JP7696751B2 - Ammonia mixed fuel, ammonia mixed fuel manufacturing device, ammonia mixed fuel manufacturing method, ammonia mixed fuel supply device, ammonia mixed fuel combustion device, power generation equipment using ammonia mixed fuel, and transportation equipment using ammonia mixed fuel - Google Patents

Description

The present invention relates to an ammonia-mixed fuel, an apparatus for producing an ammonia-mixed fuel, a method for producing an ammonia-mixed fuel, an apparatus for supplying an ammonia-mixed fuel, an apparatus for burning an ammonia-mixed fuel, a power generation facility using an ammonia-mixed fuel, and a transport device using an ammonia-mixed fuel.

Due to recent regulations on greenhouse gas (GHG) emissions, there is a demand for a shift from the conventionally widely used fossil fuels (e.g., gasoline, kerosene, diesel, heavy oil, coal, etc.) that generate carbon dioxide when burned to other fuels that can suppress GHG emissions. In contrast, ammonia does not contain carbon, so it does not generate carbon dioxide when burned. For this reason, ammonia has been considered promising in recent years as an alternative fuel to comply with GHG regulations.
However, since ammonia has a much higher ignition temperature and a much slower combustion speed than conventional fossil fuels, it is difficult to stably burn ammonia alone.
For this reason, a technique is known in which a liquid hydrocarbon fuel such as diesel or a gas fuel such as methane or hydrogen is added to ammonia as a combustion improver for assisting the combustion of ammonia.

For example, it has been reported that in a combustion device simulating a two-stroke diesel engine capable of periodically pressurizing and compressing the mixed gas in the combustion chamber, the diffusion combustion required for the operation of a diesel engine is made possible by directly injecting pressurized liquefied ammonia and a small amount of diesel fuel as pilot fuel into the combustion chamber into which air is introduced (Non-Patent Document 1).
According to the above-mentioned Non-Patent Document 1, in the direct injection combustion of liquefied ammonia, liquefied ammonia is injected into a diesel engine and vaporized in the same manner as conventional volatile hydrocarbon fuels, and is heated by auto-ignition combustion after vaporization of the pilot fuel diesel, causing the ammonia to ignite and undergo diffusion combustion.

Also, Non-Patent Document 2 reports that pre-vaporized ammonia, which is equivalent to 70% of the total calorific value, is mixed with hydrogen as a combustion improver, which is equivalent to 30% of the total calorific value, nitrogen in a volume ratio of 1/3 of the hydrogen, and a certain amount of air, and then injected into the combustion device of a four-stroke engine and ignited by spark, so that the mixture can be burned with an unburned rate of 2%, thereby operating the engine. Here, nitrogen is added to the fuel gas in order to simulate a situation in which hydrogen produced on the spot by catalytic decomposition of part of ammonia (reaction formula: _NH3 → 3/ _2H2 + 1/ _2N2 ) is used as a combustion improver when it is put into practical use, and the nitrogen produced as a by-product at that time is also added to the fuel gas.

In addition, Non-Patent Document 3 reports on the evaluation of laminar burning velocity of premixed gas made by mixing prevaporized ammonia with hydrogen or methane and a specified amount of air, and the evaluation of turbulent burning behavior assuming application to gas turbines, etc., in order to increase the burning velocity and stabilize the combustion. In this document, it is confirmed that the laminar burning velocity of ammonia, which is low at about 7 cm/s at 25°C under atmospheric pressure, increases when mixed with methane (laminar burning velocity about 37 cm/s) or hydrogen (about 220 cm/s).

On the other hand, in recent years, from the environmental viewpoint of preventing ozone layer destruction and global warming caused by refrigerants used in refrigerators, air conditioners, etc., liquefied ammonia, liquefied propane, and other hydrocarbon components of liquefied petroleum gas have been attracting attention as "natural refrigerants" that can replace conventional fluorocarbons and alternative fluorocarbons. In addition, in order to expand the refrigerant function, the use of mixed systems of these has been assumed, and the phase equilibrium between the liquid phase and the gas phase of these mixtures has also been studied. For example, the results of evaluating the equilibrium relationship between the liquid phase and the gas phase in a two-component system of liquefied ammonia and liquefied propane, liquefied propylene, liquefied n-butane, or liquefied 1-butene have been reported (Non-Patent Documents 4 and 5).
According to the above non-patent documents 4 and 5, in a mixture of liquefied ammonia and each of the hydrocarbon species of the above liquefied petroleum gas components, a heterogeneous azeotropic vapor-liquid-liquid equilibrium relationship (VLLE) is observed between the liquid phase and the gas phase separated into two phases in a temperature range of about -10 to 20°C, and it is shown that the composition range in which the liquid phases are miscible expands with increasing temperature, and an approximate calculation of these vapor-liquid-liquid equilibrium relationships is also shown. Furthermore, it is shown that propylene and 1-butene become completely miscible with liquefied ammonia at any liquid phase composition (mixing ratio) when the temperature is increased above a certain temperature, and a homogeneous azeotropic vapor-liquid equilibrium relationship (VLE) is established between the homogeneous liquid phase and the gas phase.

Daisuke Tsuru, Dr. Tajima, "Research on Direct Injection of Ammonia Fuel" 89th Japan Marine Engineering Conference, October 3, 2019 Makoto Koike, "Development of Combustion Technology for Ammonia Reciprocating Engines", SIP (Strategic Innovation Promotion Program) Final Report (public version), March 2019 Hideaki Kobayashi, "Elucidation of the fundamental characteristics of ammonia combustion and development of fundamental technologies", SIP (Strategic Innovation Promotion Program) Final Report (public version), March 2019 K. Noda et al. , “Isothermal Vapor-Liquid and Liquid-Liquid Equilibria for the Propane-Ammonia and Propylene-Ammonia Systems”, J. Chem. Eng. Data, Vol. 38, 9-11 (1993). Y. Zhao et al. , “Apparatus for Low-Temperature Investigations: Phase Equilibrium Measurements for Systems Containing Ammonia”, J. Chem. Eng. Data, Vol. 61, 3883-3889 (2016).

Among the above reports, Non-Patent Document 1 states that liquefied ammonia can be ignited using pilot fuel diesel, but at the same time, it is recognized that ignition is poor and the flame propagation speed is small, suggesting that it is not easy to completely burn the entire amount of ammonia supplied as fuel uniformly and stably with a small amount of pilot fuel diesel. In addition, since ammonia contains nitrogen elements, there is a risk that a large amount of nitrogen oxides (NOx), including NO, _NO2 , which are harmful to the environment, and _N2O , which has a high global warming potential, will be generated, especially if combustion does not proceed uniformly and quickly.
It is also possible to improve the combustibility of liquefied ammonia by mixing it with a liquid hydrocarbon fuel such as diesel, which was used as the pilot fuel in Non-Patent Document 1. However, since highly polar liquefied ammonia and liquid non-polar hydrocarbons such as diesel are hardly compatible with each other in the liquid phase, it is difficult to mix them uniformly and stably and burn them.

In addition, in Non-Patent Documents 2 and 3, by utilizing the fact that any substances can be mixed uniformly in the gas phase regardless of polarity, hydrogen or methane gas is premixed as a combustion improver with pre-vaporized ammonia to improve combustion. However, these combustion improvers have major drawbacks in terms of storage and transportation. Ammonia itself can be easily liquefied by cooling to about -33°C under atmospheric pressure or pressurizing to about 0.8 MPa at room temperature (25°C), and can be easily stored and transported as liquefied ammonia. However, the above-mentioned hydrogen and methane cannot be liquefied unless they are cooled to extremely low temperatures of about -253°C and -162°C, respectively, under atmospheric pressure, and expensive, large-scale cooling equipment is required for liquefaction, and the energy required for cooling is also very large. Furthermore, even in a liquefied state, the volumetric energy density of hydrogen is only about 29% of that of gasoline or diesel, which is 26% smaller than the volumetric energy density of liquefied ammonia. Moreover, near room temperature, neither of them can be liquefied by pressurization (they become supercritical), and the volumetric energy density of these compressed states is even lower than that of the liquefied state. Furthermore, the solubility of non-polar methane and hydrogen gas in liquefied ammonia is low, and it is practically impossible to dissolve the amount required for combustion support in liquefied ammonia. For this reason, when using hydrogen or methane as a combustion improver, expensive and large-scale facilities are required for storage and transportation in addition to the facilities for liquefied ammonia.
In addition, Non-Patent Document 2 assumes that hydrogen as a combustion improver is obtained by catalytic decomposition of ammonia, and in this case, there is no need to store or transport hydrogen itself. However, in the stage prior to the combustion of ammonia, a certain amount of hydrogen as a combustion improver must be successively produced from ammonia that is partially branched off from the supply path to the combustion, and if any problem such as a breakdown occurs in this process, the entire system must be stopped. Therefore, this is unlikely to be a highly robust process.

On the other hand, Non-Patent Documents 4 and 5 show that liquefied ammonia and liquefied petroleum gas components such as liquefied propane are at least partially dissolved based on their gas-liquid equilibrium relationship, and also state that these components or mixtures thereof can be used as "refrigerants" that do not promote ozone layer destruction or global warming even if they are discharged into the atmosphere. However, these documents do not at all assume that they can be used as "fuels" that do not generate GHG such as _CO2 even when burned. Furthermore, there is no description or suggestion of the possibility of mixing and dispersing liquefied ammonia and liquefied petroleum gas components under conditions where the mixed liquid phase of the liquefied ammonia and liquefied petroleum gas components undergoes phase separation, the requirements for their mixing required for use as a fuel, or the types of combustion improvers that can be used other than the above-mentioned liquefied petroleum gas components.

The present invention aims to provide an ammonia-mixed fuel that can efficiently burn liquefied ammonia while suppressing emissions of GHG, NOx, etc., by stably mixing and dispersing a combustion improver that has high combustibility, storability, and transportability with liquefied ammonia, and to provide an apparatus for producing this ammonia-mixed fuel, a method for producing this ammonia-mixed fuel, and an apparatus for supplying this ammonia-mixed fuel, as well as a combustion apparatus that uses this ammonia-mixed fuel, a power generation facility that uses this ammonia-mixed fuel, and transportation equipment that uses this ammonia-mixed fuel.

One aspect of the present invention is
An ammonia-blended fuel,
Liquefied ammonia;
A combustion improver that assists the combustion of the ammonia,
The combustion improver is
(a) Liquefied petroleum gas, naphtha, gasoline, kerosene, and diesel;
(b) a feedstock hydrocarbon which is at least one hydrocarbon species contained as a component in any one of the liquefied petroleum gas, the naphtha, the gasoline, the kerosene, and the diesel; and (c) a feedstock alcohol which is an alcohol having 3 or less carbon atoms.
At least one of
The ammonia mixed fuel is characterized in that it is in a gas-liquid equilibrium state, and at least a part of a liquid phase portion of the ammonia mixed fuel is in a solution state in which the ammonia and the combustion improver are dissolved in each other, or in an emulsion state of the ammonia and the combustion improver.

Another aspect of the present invention is a manufacturing apparatus for manufacturing an ammonia-mixed fuel, comprising:
an ammonia storage sealed container for storing liquefied ammonia;
(a) a sealed container for storing a combustion improver that assists the combustion of the ammonia, the combustion improver being at least one of: (a) liquefied petroleum gas, naphtha, gasoline, kerosene, and diesel; (b) a raw material hydrocarbon that is at least one hydrocarbon species contained as a component in any one of the liquefied petroleum gas, the naphtha, the gasoline, the kerosene, and the diesel; and (c) a raw material alcohol that is an alcohol having 3 or less carbon atoms;
a mixing sealed vessel configured to obtain a dissolved solution state or an emulsified mixture by stirring and mixing the above and the combustion improver with a stirrer, and to enable the mixture obtained by stirring and mixing with the stirrer to maintain a gas-liquid equilibrium state;
an ammonia introduction line provided with an ammonia quantitative introduction mechanism configured to connect the ammonia storage sealed container and the mixing sealed container and introduce a predetermined amount of the ammonia into the mixing sealed container;
a combustion improver introduction line that connects the combustion improver storage sealed container and the mixing sealed container and is provided with a combustion improver quantity introduction mechanism configured to introduce a predetermined amount of the combustion improver from the combustion improver storage sealed container into the mixing sealed container;
and at least one liquid phase discharge line configured to discharge the mixture obtained by stirring and mixing of the agitator in the sealed mixing container from the sealed mixing container as an ammonia mixed fuel.

Another embodiment of the present invention is a supply device for an ammonia-mixed fuel, comprising:
The ammonia mixed fuel production apparatus;
and an ammonia mixed fuel supply line for supplying the ammonia mixed fuel discharged from the mixing sealed container to a combustor configured to combust the ammonia mixed fuel.
In this embodiment, the supply device may include a plurality of the combustors. In this case, it is preferable that the supply device includes a plurality of the ammonia mixed fuel supply lines so that the ammonia mixed fuel is supplied to each of the combustors.

Another aspect of the present invention is a combustion apparatus for an ammonia-mixed fuel, comprising:
a combustor configured to combust the ammonia fuel blend;
a supply device for supplying the ammonia mixed fuel to the combustor;
and a combustion gas exhaust line configured to exhaust combustion gas generated by the combustion of the ammonia mixed fuel in the combustor into the atmosphere.

Another aspect of the present invention is a power generation facility that generates power in any one of a land area, a water area, and an air area,
The power generation facility is equipped with at least one of a combustion device for the ammonia mixed fuel having an internal combustion engine and a combustion device for the ammonia mixed fuel having an external combustion engine,
A generator configured to generate electricity by utilizing mechanical power extracted by utilizing the energy of the combustion gas of the ammonia mixed fuel;
a power output terminal configured to output the power generated by the generator;
and a control mechanism configured to control the amount of power at the power output end.

Another aspect of the present invention is a transportation device configured to move or transport goods in any one of land, water, and airspace,
At least one of a combustion device for the ammonia mixed fuel having an internal combustion engine and a combustion device for the ammonia mixed fuel having an external combustion engine is installed,
and a power conversion and transmission mechanism configured to utilize the mechanical power extracted by at least one of the internal combustion engine and the external combustion engine from the energy of the combustion gas of the ammonia mixed fuel as at least a part of the power for propelling the transportation equipment.

Another aspect of the present invention is a transportation device configured to move or transport goods in any one of land, water, and airspace,
The power generation equipment is installed,
The transportation equipment is characterized in that it comprises at least one of an electric propulsion mechanism and a power supply mechanism that are configured to utilize the energy of the combustion gas of the ammonia mixed fuel to use the electricity output from the power generation facility for at least a portion of the power required for at least one of propulsion of the transportation equipment, operation control of the transportation equipment, and maintenance and management of the transportation equipment.

Another aspect of the present invention is a method for producing an ammonia-blended fuel, comprising the steps of:
(1) liquid ammonia;
(a) Liquefied petroleum gas, naphtha, gasoline, kerosene, and diesel;
(b) a feedstock hydrocarbon that is at least one hydrocarbon species contained as a component in any one of the liquefied petroleum gas, the naphtha, the gasoline, the kerosene, and the diesel; and
(c) a raw material alcohol having 3 or less carbon atoms;
and a liquid combustion improver that assists the combustion of the ammonia, which is at least one of the above, is introduced into a mixing sealed vessel;
(2) The ammonia and the combustion improver are stirred and mixed while being kept in a gas-liquid equilibrium state with a liquid phase remaining in the sealed mixing vessel, thereby producing a mixture in which at least a part of the liquid phase portions of the ammonia and the combustion improver are in a solution state in which the ammonia and the combustion improver are dissolved in each other, or in an emulsion state of the ammonia and the combustion improver;
(3) The mixture is discharged from the sealed mixing vessel as an ammonia mixed fuel.

The above-mentioned ammonia mixed fuel, the manufacturing device for the ammonia mixed fuel, the manufacturing method for the ammonia mixed fuel, the supply device for the ammonia mixed fuel, and the combustion device using the ammonia mixed fuel can uniformly and stably mix and disperse a combustion improver having high combustibility, storability, and transportability with the liquefied ammonia, thereby making it possible to efficiently combust the liquefied ammonia while suppressing emissions of GHG, NOx, etc. Therefore, the above-mentioned ammonia mixed fuel, etc. can be suitably used in power generation facilities and even transportation equipment, etc.

5A and 5B are diagrams illustrating an example of the properties (gas-liquid-liquid equilibrium state and emulsified state at a predetermined temperature) of an ammonia mixed fuel according to an embodiment. 1 is a diagram showing an example of a configuration of an apparatus for producing an ammonia-mixed fuel according to an embodiment; 3A and 3B are diagrams illustrating an example of a modification of the main part of the apparatus for producing an ammonia mixed fuel according to the embodiment of FIG. 2 . FIG. 13 is a diagram showing an example of the configuration of an apparatus for producing an ammonia-mixed fuel according to another embodiment. FIG. 13 is a diagram showing an example of the configuration of an apparatus for producing an ammonia-mixed fuel according to another embodiment. FIG. 13 is a diagram showing an example of the configuration of an apparatus for producing an ammonia-mixed fuel according to another embodiment. FIG. 13 is a diagram showing an example of the configuration of an apparatus for producing an ammonia-mixed fuel according to another embodiment. FIG. 13 is a diagram showing an example of the configuration of an apparatus for producing an ammonia-mixed fuel according to another embodiment. FIG. 13 is a diagram showing an example of the configuration of an apparatus for producing an ammonia-mixed fuel according to another embodiment. FIG. 13 is a diagram showing an example of the configuration of an apparatus for producing an ammonia-mixed fuel according to another embodiment. FIG. 13 is a diagram showing an example of the configuration of an apparatus for producing an ammonia-mixed fuel according to another embodiment. 1 is a block diagram of an example of a main part of an apparatus for producing an ammonia-mixed fuel according to an embodiment. FIG. 1A and 1B are block diagrams illustrating an example of the configuration of an ammonia mixed fuel supply device according to an embodiment. FIG. 11 is a block diagram showing an example of the configuration of an ammonia mixed fuel supply device according to another embodiment. 1 is a block diagram illustrating an example of the configuration of an ammonia mixed fuel combustion device according to an embodiment. FIG.

The following provides a detailed description of the embodiments of the ammonia mixed fuel, the ammonia mixed fuel manufacturing device, the ammonia mixed fuel manufacturing method, the ammonia mixed fuel supply device, the ammonia mixed fuel combustion device, the power generation facility using the ammonia mixed fuel, and the transportation equipment using the ammonia mixed fuel.

(Ammonia mixed fuel)
The ammonia mixed fuel of the embodiment is a fuel containing ammonia in a liquefied state (liquefied ammonia) and a combustion improver.
Since liquefied ammonia has the properties of being difficult to ignite and having a low combustion rate, a combustion improver is used to make ammonia easier to ignite and to increase the combustion rate.
As a combustion improver,
(a) Liquefied petroleum gas, naphtha, gasoline, kerosene, and diesel;
(b) a feedstock hydrocarbon which is at least one type of hydrocarbon (hereinafter also referred to as a component hydrocarbon) contained as a component in any one of the liquefied petroleum gas, the naphtha, the gasoline, the kerosene, and the diesel; and (c) a feedstock alcohol which is an alcohol having 3 or less carbon atoms.
At least one of the following is used.

Here, liquefied petroleum gas (LPG) is generally obtained from by-product gases of oil fields, natural gas fields, oil refineries, etc. as a fraction that is easily liquefied at around room temperature (25°C) using a compressor or cooling vessel. LPG contains chain hydrocarbons with 3 and 4 carbon atoms as components. LPG can be easily stored and transported after liquefaction, and the gas after vaporization is used as portable fuel or propellant fuel for mobile bodies equipped with gas engines.
Naphtha corresponds to a fraction with a boiling point range of about 30 to 200°C among products obtained by distilling and separating crude oil using an atmospheric distillation unit, and its components are mainly linear and alicyclic hydrocarbons (naphthenes) with carbon numbers of about 5 to 12, and aromatic hydrocarbons such as benzene. Naphtha is mainly used as a raw material for the petrochemical industry, as well as for gasoline, which will be described later. Naphtha and its component hydrocarbons can also be used as fuel.
Gasoline is a hydrocarbon fuel obtained mainly by refining and reforming the light fraction of the naphtha, and like naphtha, it is a mixture of hydrocarbons with a carbon number of about 5 to 11, and is a petroleum product with a boiling point in the range of about 30° C. to 220° C. and a flash point of −40° C. or less. Compared to naphtha, gasoline contains mainly aromatic hydrocarbons such as toluene and branched hydrocarbons generated by reforming, which gives it a higher octane number and makes it a fuel that can be stably burned, especially in gasoline engines, and it is widely used as a propellant fuel for vehicles such as automobiles.
Kerosene is a petroleum product mainly composed of linear hydrocarbon components with a carbon number of about 8 to 15, which corresponds to the fraction with a boiling point in the range of about 150 to 280° C. Products based on kerosene that have been refined as required and have anti-freezing components added are used as heating fuel (kerosene), as well as jet engine fuel for aircraft, rocket fuel, etc., and in this specification, kerosene includes these products.
Diesel fuel is a petroleum product with a boiling point in the range of approximately 180°C to 350°C, and is mainly composed of linear hydrocarbons with a carbon number of approximately 10 to 22. Diesel fuel is widely used for thermal power generation, large land vehicles, and propulsion of trains and ships, as a fuel that burns particularly well in diesel engines.

The feedstock hydrocarbons contained in the liquefied petroleum gas, naphtha, gasoline, kerosene, and diesel are generally mainly composed of linear, branched, or alicyclic saturated hydrocarbons having 3 to 20 carbon atoms, and/or unsaturated hydrocarbons such as alkenes and aromatics. Specific components of liquefied petroleum gas include propane, propylene, n-butane, isobutane, 1-butene, cis-2-butene, trans-2-butene, and isobutene. Naphtha contains, as components, linear and branched saturated hydrocarbons such as n-pentane, isopentane, neopentane, n-hexane, n-octane, and n-decane, linear and branched unsaturated hydrocarbons such as 1-pentene, 1-hexene, and isopentene, alicyclic hydrocarbons such as cyclohexane and cycloheptane, and isomers thereof. In order to improve the octane number, gasoline contains mainly branched saturated or unsaturated hydrocarbons and aromatic hydrocarbons such as toluene produced by reforming naphtha, with linear saturated hydrocarbon components removed. Kerosene and diesel are mainly composed of linear saturated hydrocarbons with larger molecular weights than the hydrocarbon species in gasoline, and kerosene mainly contains a series of linear saturated hydrocarbon species, such as n-tridecane and n-tetradecane with carbon numbers of 13 to 14, and diesel mainly contains n-pentadecane and n-hexadecane with carbon numbers of 15 to 16.
The above-mentioned liquefied petroleum gas, naphtha, gasoline, kerosene, diesel, and the above-mentioned feedstock hydrocarbons are generally obtained from fossil fuels extracted from nature or from fossil fuels through separation, refining, reforming, and the like, but as long as they have roughly the same chemical structure, as described below, they may be bio-derived extracts or reformed products thereof, or may be synthetic products with roughly equivalent components.

Liquefied petroleum gas, naphtha, gasoline, kerosene, diesel, and the above-mentioned feedstock hydrocarbons that are components of these can all act as combustion improvers to compensate for the difficulty of igniting ammonia. The ignition point of ammonia is about 650°C, which is extremely high compared to methane (about 540°C), a hydrocarbon known to have a particularly high ignition point, making it difficult to ignite. On the other hand, for example, although there are some differences depending on the person who measures, the ignition points of liquefied petroleum gas (ignition point about 400°C), naphtha (about 230 to 290°C), gasoline (about 300°C), kerosene (about 220°C), diesel (about 250°C), and propane (about 430°C) and n-butane (about 365°C), which are components of liquefied petroleum gas, cyclohexane (245°C), which is a component of naphtha, n-hexane (about 220°C) and toluene (480°C), which are components of naphtha and gasoline, n-decane (about 210°C), which is a component of kerosene, and n-hexadecane (about 200°C), which is a component of diesel, are all low, compensating for the difficulty of igniting ammonia. In addition, liquefied petroleum gas, naphtha, gasoline, kerosene, diesel, and the hydrocarbon species that are their constituents generally have a higher burning speed than ammonia (for example, their laminar burning speeds at atmospheric pressure and room temperature (25°C) are equal to or greater than that of methane, and are about 5 to 7 times the laminar burning speed of ammonia, which is about 7 cm/s). For this reason, the low flammability of ammonia can be compensated for by adding the above-mentioned feedstock hydrocarbons of liquefied petroleum gas, naphtha, gasoline, kerosene, diesel, and the constituents of these as combustion improvers.

The raw material alcohols include methanol, ethanol, n-propanol, and isopropanol. These raw material alcohols also have lower ignition points than ammonia (the ignition points of methanol, ethanol, n-propanol, and isopropanol are about 385°C, about 384°C, about 370°C, and about 450°C, respectively), and all have high combustion speeds (about 6 to 7 times that of ammonia in laminar combustion speed), so they can also be used as combustion improvers. In addition, like ammonia, these raw material alcohols hardly produce soot when burned, so they have the advantage of making it easier to keep the inside of the combustor (including the sliding parts of reciprocating engines, etc.) and the inside of the flue clean during combustion.

According to the following embodiment of the present invention, the ammonia mixed fuel, which is a mixture of liquefied ammonia and such a combustion improver, can have at least a part of its liquid phase in a solution state in which the ammonia and the combustion improver are dissolved in each other, or in an emulsion state of the ammonia and the combustion improver.
For example, when liquefied ammonia is mixed with liquefied petroleum gas in a liquid state or its component hydrocarbon species as a combustion improver in a closed space, a thermodynamic vapor-liquid equilibrium relationship (a phase equilibrium relationship between the gas phase and the liquid phase (two-phase separation or miscibility), or between the liquefied petroleum gas as a mixture of the component hydrocarbon species, as described below, is established between the ammonia and the liquefied petroleum gas as each of the component hydrocarbon species or a mixture of them. Based on this relationship, although there are differences depending on the component hydrocarbon species, simply mixing these with liquefied ammonia makes them at least partially miscible and thermodynamically stable. If the temperature is further increased, the proportion of these combustion improvers that are miscible with ammonia can be further increased, and they can even be completely miscible. In addition, by further adding a suitable surfactant (an example of the embodiment will be shown later), it is possible to homogenize at least a portion of the remaining parts of these combustion improvers that could not be dissolved by simple mixing at a specified temperature as an emulsion state at that temperature.
In addition, in the case of naphtha, gasoline, kerosene, and diesel fuel, which are made up of hydrocarbon species having 5 or more carbon atoms, and in the case of using these component hydrocarbon species as a combustion improver, as described later, a thermodynamic gas-liquid equilibrium relationship (a phase equilibrium relationship between a gas phase and a liquid phase (two-phase separation or miscibility), i.e., a two-phase gas-liquid or three-phase gas-liquid or three-phase gas-liquid-liquid) is established, and ammonia can be dissolved under gas-liquid equilibrium conditions in a closed space. For example, naphtha containing many branched chain hydrocarbon species, alicyclic hydrocarbon species, and aromatic hydrocarbons such as benzene, which have higher dispersibility than straight chain hydrocarbon species, has a relatively high compatibility with ammonia. In addition, gasoline containing many aromatic hydrocarbon species that are non-polar or low polar but have a large induced dipole in addition to branched chain hydrocarbon species has a high compatibility with liquefied ammonia (see Example 14 described later). For example, the above-mentioned benzene and aromatic hydrocarbon species such as toluene, o-, m-, and p-xylene, which are contained in large amounts as components in commercially available gasoline, are completely miscible with liquefied ammonia at around room temperature (25° C.), regardless of the mixing ratio, as with the above-mentioned methanol.
In addition, by adding a suitable surfactant as described below, it is possible to further solubilize at least a portion of the liquefied petroleum gas and its component hydrocarbons in an emulsion state, as in the case of liquefied petroleum gas and its component hydrocarbons, thereby improving the combustibility of the entire mixed fuel more uniformly.
When ammonia and these combustion improvers are in a solution or emulsion state, a situation arises in which the vaporized ammonia is mixed in the vicinity of these combustion improvers that are vaporized and ignited during combustion, and the vaporized ammonia is inductively ignited and the combustion speed is also improved, resulting in the realization of good, simultaneous and uniform combustion overall.
In addition, the raw material alcohol having 3 or less carbon atoms is a liquid having the same polarity as liquefied ammonia at around room temperature (25°C) and atmospheric pressure, and has a high affinity due to the effect of hydrogen bonds acting between the molecules, so it is compatible with liquefied ammonia in a wide composition range. Furthermore, in a mixture of liquefied ammonia and the raw material alcohol, hydrogen bonds are formed between the molecules of both, suppressing the vaporization of ammonia, so that the saturated vapor pressure of the mixed solution is lower than the saturated vapor pressure of ammonia alone at the same temperature. This means that when storing a solution of liquefied ammonia and the raw material alcohol, the pressure resistance of a storage container when storing at around room temperature (25°C) and the energy required for cooling when cooling and liquefying at around atmospheric pressure can be significantly reduced compared to the case of ammonia alone, which is a great advantage in storage and transportation. In other words, it has excellent storage properties and transportability.
In addition, during combustion, ammonia and the raw material alcohol are in a solution state, and thus, as in the case of mixing with the above-mentioned hydrocarbon species, a very uniform mixed gas of these is generated after vaporization, and the raw material alcohol dissolved in ammonia acts as a combustion improver, so that the ignition point is lowered and the ignition ability is improved, and the burning speed is also improved, compared to when ammonia is used alone, resulting in improved combustibility. However, it is known that, among these raw material alcohols, ethanol may react with ammonia in the solution and decompose, albeit gradually, which may increase the risk of fire, etc. For this reason, it is preferable that ammonia-mixed fuel containing ethanol is not stored for a long time after production, but is quickly burned and consumed as fuel, unless an additive or the like that inhibits such a reaction is added.

The mass ratio of ammonia and the combustion improver is appropriately determined according to the application and purpose of the mixed fuel. For example, when the purpose is to replace a portion of a hydrocarbon fuel such as liquefied petroleum gas, naphtha, gasoline, kerosene, and diesel fuel and their component hydrocarbon species with liquefied ammonia (for example, the ammonia content is about 1 mass% or more and 20 mass% or less) and suppress the generation of CO ₂ generated during combustion, the mass of these combustion improvers is relatively greater than the mass of ammonia. In such a composition ratio, in a closed space in a temperature range up to about 50°C close to room temperature (25°C), the liquefied ammonia and the combustion improver can be made to be compatible with each other in most parts, or can be made emulsified by adding a suitable surfactant described later. A mixed fuel with such a mass ratio is advantageous when performing a certain GHG emission suppression while continuing to use a combustor, burner, internal combustion or external combustion engine, or other existing combustion device that is compatible with the hydrocarbon fuel that has been used until now.
Conversely, it is also possible to prepare a mixed fuel containing liquefied ammonia as the main component and a relatively small amount of the above-mentioned hydrocarbon fuel and its component hydrocarbon species or the above-mentioned raw material alcohol as a combustion improver (for example, when the ammonia content is about 80 mass% or more and 99 mass% or less). Even with such a mass ratio, the liquefied ammonia and the combustion improver can be made to be compatible with each other in the temperature range up to about 50°C, which is close to room temperature (25°C), in most of the total volume, or can be made to be emulsified by adding a suitable surfactant, which will be described later. When such a mixed fuel containing liquefied ammonia as the main component is used, it is possible to more significantly suppress GHG emissions.

In addition, when the combustion improver is liquefied petroleum gas, naphtha, gasoline, and their component hydrocarbons, or raw material alcohol having 3 or less carbon atoms, the mixing and dispersing property with liquefied ammonia is high, so even if the mixed fuel has an ammonia content of about 20 to 80 mass%, which is intermediate between the two cases shown in the mass ratio, most of the part can be made compatible with the total volume by stirring in a temperature range from about room temperature (25°C) to about 50°C, or it can be emulsified by adding a suitable surfactant described below. On the other hand, when the combustion improver is kerosene, light oil, and their component hydrocarbons, the mixing and dispersing property with liquefied ammonia is low in a temperature range from about room temperature (25°C) to about 50°C, in a mixing ratio where the ammonia content is about 20 to 80 mass% and the mass ratio with the combustion improver is antagonistic, even if a suitable surfactant described below is used, the required amount of the surfactant to be added is significantly large (for example, an amount equivalent to about 10 mass% or more is required) in order to uniformly disperse the whole as an emulsion. It is also difficult to disperse a large amount of surfactant sufficiently. Therefore, in such a mixed composition, it is difficult to avoid that a liquid phase separation will remain (for this reason, the amount of either liquefied ammonia or combustion improver added is limited to the upper limit amount that can be solubilized or emulsified, etc.). However, if a suitable surfactant described later is used, even if the liquid phase is separated by adding up to about 5 mass%, the combustion improver (kerosene, light oil, and their component hydrocarbons) can be emulsified and dispersed up to about 10 mass% in the ammonia side phase, which is inferior in combustion, of the separated two phases, so that the combustibility of such ammonia side phase in which the combustion improver is dispersed is improved compared to when liquefied ammonia is used alone. Note that the other phase of the liquid phase separation is mainly composed of the combustion improver, so its combustibility is high. As described later, kerosene and its component hydrocarbons can be made compatible with liquefied ammonia over a wide range of mixing ratios by heating them to about 50 to 100°C, and light oil and its component hydrocarbons can be made compatible with liquefied ammonia over a wide range of mixing ratios even without the addition of a surfactant, if heated to about 50 to 100°C, and light oil and its component hydrocarbons can be made compatible with liquefied ammonia over a wide range of mixing ratios even if no surfactant is added (at temperatures above about 130°C, the mixture becomes subcritical or supercritical and is compatible).
In the above-mentioned combustion improver for ammonia mixed fuel, even when both the feedstock hydrocarbon and the feedstock alcohol are contained, the mass ratio of each is appropriately determined according to the application and purpose of the mixed fuel.

In the ammonia mixed fuel, the proportion of the mixed solution or emulsion state to the total amount is preferably as large as possible, and if possible, it is preferable that the equilibrium stable composition is maintained as it is after production. This makes it possible to more uniformly improve the overall combustibility of the ammonia mixed fuel. In addition, if the liquid phase is separated into two phases when the ammonia mixed fuel is sent through a piping system, the phases are separated into layers in the vertical direction in the piping system due to the specific gravity difference between the phases, and one of the phases is likely to remain in a stagnant place in the piping system, which may result in a situation where the composition of the ammonia mixed fuel is shifted at the liquid sending outlet. However, the greater the proportion of the mixed solution or emulsion state to the total amount, the easier it is to prevent such a situation where the composition is shifted.
In particular, when the combustion improver added to ammonia is liquefied petroleum gas, naphtha, gasoline, and their component hydrocarbons, and the above-mentioned raw material alcohol, which are compatible to a considerable extent due to equilibrium relationships even without the addition of a surfactant, the portion that has once been compatible will remain in a thermodynamically stable solution state and will remain compatible as such permanently as long as the temperature at which it was dissolved is maintained and the gas-liquid equilibrium state is maintained (however, as described above, when the combustion improver contains ethanol, the reaction with ammonia will gradually proceed).
The longer the time for which the emulsion state formed after mixing and dispersion is stably maintained, the better. The stable maintenance time is, as a guideline, at least about 5 minutes, preferably several days, and more preferably about one month or more, in terms of storage and use as a fuel. In particular, when an emulsion-state mixed fuel is prepared by adding a sufficient amount of a suitable surfactant described below and stirring at an appropriate temperature, the emulsion once formed maintains the temperature at which it was dissolved and maintains a thermodynamically metastable state as long as the gas-liquid equilibrium state is maintained, and therefore the dispersed state can be maintained for a long period of time, from one day to several days to about one month or more.
In the case where the ammonia mixed fuel is in a non-equilibrium transient emulsion state and the components undergo phase separation during storage, it is advisable to re-agitate and mix the ammonia mixed fuel to return it to an emulsion state before supplying it to the combustor. At that time, if necessary, the temperature is appropriately adjusted as described below. This makes it possible to restore the combustion advantages of the ammonia mixed fuel.
Furthermore, it is preferable that the ammonia mixed fuel is maintained at a predetermined temperature according to the liquid phase composition such that the entire liquid phase portion of the ammonia mixed fuel is in a solution state in which the ammonia and the combustion improver are dissolved in each other, or in an emulsion state of the ammonia and the combustion improver.
As described later, the composition and temperature of the constituent components of the ammonia-mixed fuel can be kept at an appropriate composition and in an appropriate temperature range according to the composition, or a sufficient amount of a suitable surfactant described later can be added and mixed and dispersed, so that the entire liquid phase portion of the ammonia-mixed fuel is in a solution state in which the ammonia and the combustion improver are dissolved in each other, or in an emulsion state of the ammonia and the combustion improver. By keeping the entire liquid phase portion of the ammonia-mixed fuel in a solution state in which the ammonia and the combustion improver are dissolved in each other, or in an emulsion state of the ammonia and the combustion improver, the overall combustibility of the ammonia-mixed fuel can be improved uniformly and to the highest degree.

In particular, ammonia (containing no carbon at all), liquefied petroleum gas, and raw material alcohols having three or less carbon atoms emit less _CO2 per calorific value than gasoline, kerosene, light oil, heavy oil, coal, and other fossil fuels that have traditionally been widely used. Therefore, ammonia-mixed fuels that are mixed with these as a combustion improver are themselves very effective fuels in reducing greenhouse gas (GHG) emissions such as _CO2 .
In addition, the aforementioned liquefied petroleum gas, naphtha, gasoline, kerosene, diesel, and hydrocarbon species having the same structure as the feedstock hydrocarbons of these components, as well as feedstock alcohols having 3 or less carbon atoms, excluding ethanol, may be produced by chemical synthesis via CO or methane, which is synthesized by reducing _CO2 separated and collected from industrial exhaust gas or the atmosphere, using electricity obtained from renewable energy sources such as solar, wind, hydroelectric, and geothermal energy, or nuclear power, or hydrogen obtained by electrolysis of water using said electricity. Unlike the case of fossil fuels, with regard to such feedstock hydrocarbons and the aforementioned feedstock alcohols produced using renewable energy, even if they are burned and the exhaust gas is released into the atmosphere, it is considered that _CO2 emissions are substantially suppressed.
It is also known that many of the hydrocarbons with the same structure as these and raw material alcohols with 3 or less carbon atoms, including methanol and ethanol, can be synthesized from raw materials such as metabolic products of plants and microorganisms that perform photosynthesis. When such products based on photosynthesis or metabolic products are used as combustion improvers, the carbon contained therein is derived from atmospheric _CO2 , so it is considered that the amount of _CO2 in the atmosphere is not substantially increased even when burned. Therefore, the use of ammonia-mixed fuel mixed with the above-mentioned renewable energy-based combustion improver and the bio-derived combustion improver based on photosynthesis can highly suppress global warming.

In order to store and transport the ammonia mixed fuel so that the fuel can be steadily supplied in a liquefied state, it is preferable to store it in isolation in a sealed environment where gas-liquid equilibrium is maintained.

In one embodiment, the ammonia mixed fuel contains at least one of the liquefied petroleum gas, the feedstock hydrocarbon, and the feedstock alcohol as a combustion improver, and the feedstock hydrocarbon is at least one hydrocarbon species contained as a component in the liquefied petroleum gas, and the feedstock alcohol is preferably methanol. That is, the ammonia mixed fuel preferably contains at least one of the liquefied petroleum gas, the at least one hydrocarbon contained as a component in the liquefied petroleum gas, and methanol as a combustion improver.
Liquefied petroleum gas and the hydrocarbons contained as its constituent components are preferable in that they generate less _CO2 per calorific value when combusted, compared to gasoline, kerosene, light oil, or heavy oil, which have traditionally been widely used as liquid fuels.
As described above, liquefied petroleum gas and the hydrocarbon species contained as its constituent components have a saturated vapor pressure relatively close to that of ammonia when in a liquid state at the same temperature, and have a lower ignition temperature than lower molecular weight hydrocarbons such as methane, making them easier to ignite. In addition, they have a burning speed that is approximately 5 to 6 times that of ammonia and is equal to or greater than that of methane, making them advantageous as a combustion improver for ammonia.
Therefore, when the liquefied petroleum gas or its component hydrocarbons and ammonia are in a solution or emulsion state, they are vaporized almost simultaneously and uniformly in a very uniformly mixed state during combustion, and the vaporized mixed gas is easily heated simultaneously and uniformly. Therefore, when the liquefied petroleum gas or its component hydrocarbons such as propane are vaporized and ignited in the combustor, the vaporized ammonia mixed very close to the liquefied petroleum gas or its component hydrocarbons is heated and ignited, and as a whole, particularly good simultaneous and uniform combustion can be realized.

Among the liquid fossil fuels that have been widely used as fuels, kerosene, diesel, and the hydrocarbon species of these components, excluding gasoline, are mainly non-polar linear saturated hydrocarbons with a carbon number of about 8 or more. In general, a mixture of such non-polar linear saturated hydrocarbon species with a carbon number of about 8 or more and liquefied ammonia is not easily mixed with each other under the gas-liquid equilibrium conditions in the temperature range from about room temperature (25°C) to about 50°C, and separates into two phases. In order to make them compatible without adding a surfactant, which will be described later, it is necessary to heat them to a higher temperature than liquefied petroleum gas and its component hydrocarbon species (for example, about 50 to 100°C for kerosene and its component hydrocarbon species, and about 80 to 130°C for diesel and its component hydrocarbon species), and at that time, the saturated vapor pressure, which is mainly governed by the vaporization properties of ammonia, increases (for example, about 3 to 4 MPa or more), so that the manufacturing equipment for manufacturing and storing the mixed fuel is required to have high pressure resistance. For this reason, in order to stably and precisely mix such non-polar linear saturated hydrocarbons having a carbon number of approximately 8 or more with liquefied ammonia for combustion, it is generally necessary to emulsify the mixture by adding and mixing a specific surfactant as described below.
On the other hand, eight types of hydrocarbons with carbon numbers of 3 and 4 (propane, propylene, n-butane, isobutane, 1-butene, cis-2-butene, trans-2-butene, and isobutene), which are the main components of liquefied petroleum gas, are non-polar, but are uniformly compatible with highly polar liquid ammonia in almost any composition range under gas-liquid equilibrium conditions at a predetermined temperature of about 40° C. or less and in an enclosed space with a saturated vapor pressure of about 2 MPa or less, even without adding a surfactant. The compatibility of ammonia and low molecular weight hydrocarbons and the related equilibrium relationship between the gas-liquid phase are partially shown in Non-Patent Documents 4 and 5, which relate to the mixed properties of ammonia and low molecular weight hydrocarbons as refrigerants. Below, based on the data described in Non-Patent Documents 4 and 5, the situation in which the liquefied ammonia and the combustion improver are compatible with each other and the situation in which they are in an emulsion state will be described using the cases in which propane and n-butane, which are the main components of liquefied petroleum gas, are used as combustion improvers as examples.

1(a) and (b) show the vapor-liquid-liquid equilibrium (VLLE) relationships of an ammonia-propane system and an ammonia-n-butane system, respectively, described in Non-Patent Documents 4 and 5. (In FIGS. 1(a) and (b), the ammonia concentrations (x, y) in the liquid and gas phases are converted from the mole fraction representation used in Non-Patent Documents 4 and 5 to mass %).
1(a) shows the relationship between the gas-liquid composition and the saturated vapor pressure in the vapor-liquid-liquid equilibrium (VLLE) of a heterogeneous azeotropic system of an ammonia-propane system at 20° C. (upper panel) and 0° C. (lower panel). The solid line in the figure (the locus of PABQ at 20° C. and P'A'B'Q' at 0° C.) shows the relationship (liquidus) between the liquid phase composition (x) and the saturated vapor pressure (p), and the dashed line below (the locus of POQ at 20° C. and P'O'Q' at 0° C.) shows the relationship (vapor phase) between the gas phase composition (y) in equilibrium with the liquid phase and the saturated vapor pressure (p). At 20° C., the ammonia concentration in the liquid phase increases from point P where the gas-liquid phase composition x, y = 0, which indicates the gas-liquid equilibrium of pure propane, until point A (ammonia concentration x _A = 16.2 mass %) is reached at which the dissolution of ammonia is saturated. Ammonia continues to dissolve uniformly in the liquid phase mainly composed of propane, and the saturated vapor pressure increases while maintaining a single liquid phase state.
When the ammonia concentration in the liquid phase reaches point A, where it becomes the saturated concentration _xA (at this time, the gas phase reaches point O, where the saturated vapor pressure becomes maximum (azeotropic point: gas phase ammonia concentration _yO = 31.2 mass%, saturated vapor pressure _pO = 1.64 MPa)), the ammonia concentration in the liquid phase mainly composed of propane does not increase any more, and another liquid phase mainly composed of ammonia appears, which is phase-separated from the liquid phase mainly composed of ammonia. In this phase-separated liquid phase mainly composed of ammonia, propane is saturated and dissolved (ammonia concentration in the phase _xB = 86.5 mass%, propane concentration (saturated) 1 - _xB = 13.5 mass%). In the region where the liquid phase composition ranges from _xA to _xB (on the line segment AB of the liquidus line), two phase-separated phases, a propane-based liquid phase with an ammonia concentration of _xA and an ammonia-based liquid phase with an ammonia concentration of _xB , coexist, and during that time, the gas phase is maintained in an azeotropic state (point O) with an ammonia concentration of _yO and a saturated vapor pressure of _pO , which is in equilibrium with the liquid phase. In addition, at point C (ammonia concentration _xC ) on the line segment AB in the region where the liquid phase separates into two phases, the mass ratio of the propane-based phase with an ammonia concentration of _xA and the ammonia-based phase with an ammonia concentration of _xB is expressed by the "lever principle" as ( _xB - _xC ):( _xC - _xA ).
When the ammonia concentration in the liquid phase increases beyond _xB (point B on the liquidus line), the phase mainly composed of propane disappears, and the liquid phase becomes a single phase mainly composed of the ammonia dissolved in propane. If the ammonia concentration in the phase is further increased, the single phase will pass through the BQ locus on the liquidus line and reach point Q in the figure showing the gas-liquid equilibrium of pure ammonia. The composition and saturated vapor pressure of the gas phase in equilibrium with this will draw the OQ locus on the gas phase line, and the saturated vapor pressure will decrease to point Q as the gas-phase ammonia concentration increases. Since the above behavior is based on a thermodynamic equilibrium relationship, it will be the same even if the ammonia concentration is decreased from point Q, which shows the gas-liquid equilibrium of pure ammonia.

From the above, at 20°C, ammonia can be dissolved in the liquid phase mainly composed of propane in a thermodynamically stable manner without phase separation up to its saturation concentration x _A (=16.2 mass%), via the trajectory PA in Fig. 1(a). Also, propane can be dissolved in the liquid phase mainly composed of ammonia in a thermodynamically stable manner without phase separation up to its saturation concentration 1-x _B (=13.5 mass%), via the trajectory QB in the same figure. Assuming a mixed fuel at 20°C in which liquefied propane is dissolved as a combustion improver in liquefied ammonia, the propane-based liquid phase of the above two liquid phases corresponds to a case in which the amount of liquefied propane as a combustion improver is significantly greater than that of liquefied ammonia. By replacing a part of the liquefied propane (here, 16.2 mass% or less) with ammonia, if this is taken out as a mixed fuel and used for combustion, it becomes a single-phase miscible mixed fuel that burns uniformly as a whole, and the generation of _CO2 can be suppressed by the amount of the replacement compared to when liquefied propane is burned alone. Moreover, of the above two liquid phases, the liquid phase mainly composed of ammonia corresponds to a case where the amount of liquefied propane as a combustion improver is less than that of liquefied ammonia. By replacing a part of the liquefied ammonia (here, 13.5 mass% or less) with propane, if this is taken out as a mixed fuel and used for combustion, it becomes a single-phase miscible mixed fuel that burns uniformly as a whole, and the combustibility can be improved by the amount of the replacement compared to when liquefied ammonia is burned alone.
In addition, in the gas-liquid-liquid equilibrium relationship at 20°C in Fig. 1(a), at point C where the liquid phase ammonia concentration is _xC , the liquid phase separates into two phases (at this time, due to the difference in specific gravity, the upper layer is a phase mainly composed of propane (ammonia concentration _xA = 16.2 mass%), and the lower layer is a phase mainly composed of ammonia (ammonia concentration _xB = 86.5 mass%)). At this time, when point C is located close to point B as shown in the figure, the mass of the liquid phase mainly composed of propane is relatively small compared to the mass of the liquid phase mainly composed of ammonia due to the above-mentioned "leverage principle". When the entire amount is taken out as a mixed fuel and subjected to combustion, the uniformity of combustion as a mixed fuel is inferior to that of the single-phase miscible mixed fuel described above due to phase separation, but the small amount of the liquid phase mainly composed of propane that has separated into phases is also originally highly combustible, so it can be burned well overall. On the other hand, even when point C is located close to point A, if the entire amount is extracted as a mixed fuel and subjected to combustion, the uniformity of combustion as a mixed fuel is inferior to that of the above-mentioned single-phase miscible mixed fuel, but the liquid phase mainly composed of ammonia that has separated into a small amount of phases is also saturated with propane at a concentration of 1- _xB (=13.5 mass%) and is therefore given a combustion-supporting effect, so that the mixture can be combusted well overall. Furthermore, as described below, if the upper and/or lower layers separated into two phases can be extracted separately as mixed fuel and each layer can be subjected to combustion separately, each layer itself becomes a single-phase mixed fuel, and each layer will exhibit uniform and good combustibility.

In the gas-liquid-liquid equilibrium relationship of the ammonia-propane system at 0°C shown at the bottom of Fig. 1(a), the liquidus is represented by the locus of P'A'B'Q', and the gasus is represented by the locus of P'O'Q'. At 0°C, the two-phase separation region in the liquid phase (between A'B' on the liquidus) is enlarged, and the single-phase regions on both sides (between P'A' and B'Q' on the liquidus) are reduced, compared to the above-mentioned 20°C, and the saturated vapor pressure, including the azeotropic vapor pressure pO _' (=0.66 MPa) at the azeotropic point O', is generally lower than that at 20°C. The reduction in the single-phase region (between P'A' and B'Q' on the liquidus) indicates that the compatibility between liquefied ammonia and liquefied propane is reduced by the decrease in temperature. Therefore, when this system is used as a single-phase miscible mixed fuel at 0°C, it is possible to dissolve ammonia up to a concentration xA _' (=6.7 mass%) in the liquid phase mainly composed of propane, and propane up to a concentration 1-xB _' (=6.5 mass%) in the liquid phase mainly composed of ammonia, but the solubility of each is lower than at 20°C.
FIG. 1(b) shows the relationship between the gas-liquid composition and the saturated vapor pressure in the gas-liquid-liquid equilibrium (VLLE) of the ammonia-n-butane system at 0° C. For comparison with the ammonia-propane system, the symbols (P', A', B', Q', O', etc.) in the figure are the same as the corresponding symbols in the ammonia-propane system at 0° C. in FIG. 1(a). In the gas-liquid-liquid equilibrium relationship of the ammonia-n-butane system at 0° C. in FIG. 1(b), the liquidus line shown by the solid line (locus of P'A'B'Q') and the gasus line shown by the dashed line (locus of P'O'Q') are also recognized, and are qualitatively common to the gas-liquid-liquid equilibrium of the ammonia-propane system in FIG. 1(a). That is, when this system is used as a single-phase miscible mixed fuel at 0°C, ammonia can be dissolved in the liquid phase mainly composed of n-butane up to a concentration xA _' (=5.2 mass%), and n-butane can be dissolved in the liquid phase mainly composed of ammonia up to a concentration 1-xB _' (=2.7 mass%). Also, reflecting the lower volatility of n-butane compared to propane, the saturated vapor pressure, including the azeotropic vapor pressure pO _' (=0.53 MPa) at the azeotropic point O', is generally lower than that of the ammonia-propane system. Despite the above differences, the vapor-liquid equilibrium relationship of the ammonia-n-butane system is qualitatively common to the vapor-liquid equilibrium relationship of the ammonia-propane system described above in that it has a temperature and composition region where the liquid phase separates into two phases.

In general, not only the above-mentioned propane and n-butane, but also the other component hydrocarbons of liquefied petroleum gas each qualitatively exhibit a heterogeneous azeotropic vapor-liquid-liquid equilibrium (VLLE) relationship in a given temperature range. In addition, with a relative increase in temperature, for example, the points A and B (or A' and B') on the liquidus line shown in FIG. 1(a) approach each other, the two-phase separation region shrinks, and the compatibility increases. Furthermore, at or above each given temperature (critical solution temperature), the above-mentioned points A (or A') and B (or A') converge to the azeotropic point O (or O'), and the two-phase separation region in the liquid phase disappears. That is, it is known that the component hydrocarbons of liquefied petroleum gas become completely miscible in the liquid phase with liquefied ammonia at any composition ratio at or above the above-mentioned critical solution temperature.
Among the component hydrocarbons of liquefied petroleum gas, those with three carbon atoms (propane, propylene) and those with double bonds (propylene, various butenes) are relatively more compatible with liquid ammonia than those component hydrocarbons outside of these categories when compared at the same temperature. For example, the critical solution temperature is about 33°C for propane, a saturated straight-chain hydrocarbon with three carbon atoms, and about 38°C for n-butane, a straight-chain saturated hydrocarbon with four carbon atoms, and it has been confirmed that both are liquid-phase miscible with ammonia at any composition ratio in the temperature range above these. In addition, Non-Patent Documents 4 and 5 also report that propylene, an unsaturated straight-chain hydrocarbon with three carbon atoms, is liquid-phase miscible with ammonia at 0°C, and 1-butene, an unsaturated straight-chain hydrocarbon with four carbon atoms, is liquid-phase miscible with ammonia at 10°C, regardless of composition (however, it is not specified whether these temperatures are critical solution temperatures or not). In the temperature range above the critical solution temperature of each of the component hydrocarbons of these liquefied petroleum gases, a homogeneous azeotropic vapor-liquid equilibrium (VLE) relationship is established between the completely miscible liquid phase of these hydrocarbons and ammonia and the vapor phase.
In addition, for example, in the liquid phase composition (ammonia concentration x _C ) at point C in the gas-liquid-liquid equilibrium relationship of the ammonia-propane system at 20° C. in FIG. 1(a), as described above, the liquid phase separates at 20° C. However, even in the liquid phase composition at point C, there is always a certain temperature higher than 20° C. and lower than the above-mentioned critical solution temperature (about 33° C.) at which ammonia and propane are completely compatible with each other. For example, in the case of the liquid phase ammonia concentration _xC ≈ 77% by mass, which corresponds to the position of the composition xC at point _C in the equilibrium relationship between ammonia and propane at 20°C in Figure 1 (a) (at this time, the overall average composition of the liquid phase and the gas phase together, i.e., the ammonia concentration of the feed composition, is about 75% by mass, which corresponds to the conditions of Example 1 described later), if the temperature is about 23°C or higher, a homogeneous solution is formed without phase separation (i.e., at 23°C, points B and C overlap, and the ammonia concentration _xB corresponding to point B, which is the saturated state of propane, is about 77% by mass. See Example 1 described later). Such behavior is also observed for all component hydrocarbon species of liquefied petroleum gas other than propane. That is, in a mixed fuel of liquefied petroleum gas or a component hydrocarbon of liquefied petroleum gas and ammonia, the temperature of the mixed fuel is maintained at or above the above-mentioned temperature according to the liquid phase composition of the mixed fuel, so that the entire liquid phase portion of the mixed fuel can be made into a solution state in which the ammonia and the combustion improver are dissolved together (see Example 2 described below (when the combustion improver is n-butane)). As a result, when the entire amount is taken out as a mixed fuel and subjected to combustion, the effect of the combustion improver is maximized, and the mixed fuel can be burned extremely uniformly.

In the above-mentioned mixed system of liquefied ammonia and the component hydrocarbon species of liquefied petroleum gas, the gas-liquid-liquid equilibrium and the saturated vapor pressure at the gas-liquid equilibrium are generally higher than the saturated vapor pressures of the liquefied ammonia and the component hydrocarbon species of liquefied petroleum gas alone at the same temperature.
In addition, for single-phase compatible mixed fuels of liquefied petroleum gas component hydrocarbons other than propane, and even mixtures of liquefied petroleum gas and liquefied ammonia, the component hydrocarbons of the liquefied petroleum gas dissolved in liquefied ammonia form a uniform mixed gas with ammonia after vaporization, and act as a combustion improver in that state, as in the case of propane described above, the ignition point is lowered and ignition improves, and the burning speed also increases, resulting in improved combustibility, compared to when liquefied ammonia is used alone. On the other hand, even in a mixture composition and temperature conditions where ammonia is not completely miscible with the component hydrocarbons and phase separation occurs, the liquid phase mainly composed of ammonia produced by phase separation has liquefied petroleum gas components saturated and dissolved as a combustion improver, and the liquid phase mainly composed of the component hydrocarbons of the other liquefied petroleum gas also has good combustibility, so that good combustion can be achieved overall. Furthermore, if each phase separated is taken out separately as a mixed fuel and each is burned separately, each becomes a uniform single phase and shows good combustibility.

Methanol can also be used as a fuel that suppresses the generation of GHG, similar to liquefied petroleum gas or its components. Methanol is also easy to ignite because its ignition point is low at about 385°C, and its laminar burning velocity is about 45 cm/s, which is 6 to 7 times higher than that of ammonia, making it easy to burn, and suitable as a combustion improver for ammonia. In addition, compared to heavy oil, light oil, kerosene, and gasoline, which have traditionally been widely used as liquid fuels, methanol generates less _CO2 per calorific value during combustion. Furthermore, methanol is uniformly mixed (completely dissolved) in a liquid state with liquefied ammonia in any composition without the addition of a surfactant at least in the temperature range of about 0 to 40°C, so that the vaporized ammonia mixed very close to the ignited methanol after vaporization is heated and ignited, similar to liquefied petroleum gas or its main components, and as a whole, particularly good simultaneous and uniform combustion can be realized. In addition, methanol, like ammonia, has the advantage that it is less likely to produce soot during combustion, making it easier to maintain the cleanliness of the inside of the combustor and the flue. Unlike the case of a mixture of liquefied ammonia and liquefied petroleum gas or its component hydrocarbon species, a mixture of liquefied ammonia and methanol shows a non-azeotropic vapor-liquid equilibrium of complete liquid miscibility regardless of the liquid phase composition. Therefore, regardless of the composition ratio, if this is taken out as a mixed fuel and subjected to combustion, uniform and good combustion is possible. Furthermore, in a solution of liquefied ammonia and methanol, hydrogen bonds are formed between the molecules of both, suppressing the vaporization of ammonia, so that the saturated vapor pressure of these mixed solutions is significantly lower than the saturated vapor pressure of ammonia alone at the same temperature (see Example 13 described later). This means that when storing a mixed fuel of liquefied ammonia and methanol, the pressure resistance of the storage container when storing at around room temperature (25°C) and the energy required for cooling when storing it in a cooled liquefied state at around atmospheric pressure can be significantly reduced compared to when using ammonia alone, which is a great advantage in storage and transportation.

Furthermore, the raw materials for the ammonia-mixed fuel, i.e., ammonia, liquefied petroleum gas or its component hydrocarbons, and methanol, are also advantageous in terms of raw material procurement.
That is, ammonia has been synthesized in large quantities worldwide by the Haber-Bosch process using methane, the main component of natural gas, as a raw material. For this reason, mass synthesis plants for ammonia are often built near natural gas fields around the world. Natural gas with a high methane content, which is the raw material for ammonia, is mainly extracted from raw gas extracted from a gas field by separating hydrocarbons with higher boiling points by liquefying them under pressure or cooling. These high boiling point components generally include liquefied petroleum gas as well as naphtha components. These are separated from each other in the same natural gas refining plant and each becomes a product. Therefore, in ammonia production plants using natural gas as a raw material, liquefied petroleum gas is often co-produced in the vicinity. For this reason, when an ammonia mixed fuel is also produced incidentally in an ammonia production plant, liquefied petroleum gas and its components, such as propane and n-butane, are advantageous in terms of procuring raw materials in terms of production as a combustion improver added to the ammonia mixed fuel.

Similarly, methanol is mass-produced using methane, the main component of natural gas, as a raw material. The initial steps of methanol synthesis from methane are a desulfurization step and a steam reforming step ( _CH4 + _2H2O → _4H2 + _CO2 , and _CH4 + _H2O → _3H2 + CO), which are the same as the initial steps of ammonia production by the Haber-Bosch process from natural gas as described above. For this reason, the co-production of ammonia and methanol in the same production plant is advantageous in both terms of reducing _CO2 emissions to the environment by effectively utilizing carbon in natural gas (carbon, a component element in natural gas that is rejected in ammonia production, is utilized in methanol production) and improving efficiency by sharing the process. In fact, large-scale production plants that co-produce both have been built in recent years. Therefore, methanol can be advantageously co-produced in ammonia production plants that use natural gas as a raw material. For this reason, in the case where an ammonia-mixed fuel is incidentally produced in an ammonia production plant, methanol is also advantageous in terms of procuring raw materials as a combustion improver contained in the ammonia-mixed fuel.

Furthermore, when it is assumed that ammonia is transported in large quantities by transportation equipment from a base where it is mass-produced to a mass-consumption demand area far away, it is preferable in terms of efficiency and cost that the fuel for propelling the transportation equipment can also be procured easily and at low cost at the base where ammonia is mass-produced. As described above, liquefied petroleum gas and its component hydrocarbons, as well as methanol, can be advantageously procured at the base where ammonia is mass-produced, so that ammonia-mixed fuel containing these can be advantageously used as the driving fuel for transportation equipment that transports ammonia in large quantities. Furthermore, by taking advantage of the similarity between liquefied petroleum gas and liquefied ammonia, that is, their saturated vapor pressures and liquefaction temperatures are close, it is possible to share pressure-resistant or cooling tanks for storing them, so that currently, about 20% of liquefied petroleum gas transport ships operating around the world are designed to be able to carry liquefied ammonia as well. For this reason, being able to use the liquefied ammonia and liquefied petroleum gas and their component hydrocarbons together as fuel for the propulsion engines, such as engines, gas turbines, and steam turbines, used to propel these transport ships would not only consolidate equipment, but would also be of great significance in terms of reducing GHG emissions from the internal and external combustion engines used to propel the transport ships.

(Surfactants and emulsification with surfactants)
In one embodiment, the ammonia-mixed fuel containing the non-polar feedstock hydrocarbon, which is poorly compatible with liquefied ammonia, as a combustion improver preferably contains a surfactant to emulsify the liquid ammonia and the combustion improver. Emulsification by a surfactant can be suitably applied to any of the feedstock hydrocarbons contained in the ammonia-mixed fuel, including liquefied petroleum gas, naphtha, gasoline, diesel, and their component hydrocarbons. In particular, when the feedstock hydrocarbon is kerosene, diesel, or any of their component hydrocarbons, it is difficult to dissolve with ammonia in a temperature range from about room temperature (25°C) to about 50°C, so emulsification by adding a surfactant is necessary. By emulsification caused by the addition of a surfactant, at least a part of the phase separation portion that is not compatible in the liquid phase of the ammonia-mixed fuel at that temperature in terms of gas-liquid-liquid equilibrium can be further dispersed in the liquid phase while maintaining the temperature.
For example, in the case of an ammonia-mixed fuel using propane, a component hydrocarbon of liquefied petroleum gas, as a combustion improver, in the gas-liquid equilibrium relationship of the ammonia-propane system at 20° C. shown in FIG. 1( a), the liquid phase composition is separated into two phases at 20° C. at around point C in FIG. 1( a) (ammonia concentration x _C ≈77 mass%), but it can be uniformly emulsified by adding an appropriate amount of a suitable surfactant. For example, the upper liquid phase mainly composed of propane (ammonia concentration _xA = 16.2 mass%, mass ratio to the whole ( _xB - _xC ) / ( _xB - _xA ) ≈ 0.14) can be uniformly dispersed in the lower liquid phase mainly composed of ammonia (ammonia concentration _xB = 86.5 mass%, mass ratio to the whole ( _xC - _xA ) / ( _xB - _xA ) ≈ 0.86) by adding about 1 mass% of the same mixed surfactant as used in Example 3 described later. This uniform emulsion state is maintained even when cooled to about 17°C (the upper layer separates and appears at temperatures below 17°C). The above-mentioned emulsification can be achieved for other component hydrocarbons of liquefied petroleum gas in addition to n-butane.
The emulsification described above increases the amount of the combustion improver (liquefied petroleum gas and its component hydrocarbons) that can be dissolved in ammonia at a specified temperature, which further enhances the aforementioned combustion improver effect when the mixed fuel is burned, and also reduces the temperature required for solubilization, thereby suppressing the rise in the saturated vapor pressure of the ammonia mixed fuel. Therefore, emulsification by adding a surfactant can reduce the required pressure resistance of the storage container when storing at around room temperature (25°C).

The amount of surfactant added is adjusted depending on the molecular weight, blending composition, characteristics, and performance of the surfactant, which will be described later, but is basically appropriately determined based on the volume fraction (approximately, mass fraction is also acceptable) of the liquefied ammonia and the combustion improver that are dispersed and suspended as fine droplets in a liquid phase mainly composed of the other. For example, when liquefied ammonia becomes fine droplets (when the combustion improver is liquefied petroleum gas or its component hydrocarbons, a part of the combustion improver is dissolved in the liquid phase mainly composed of the liquefied ammonia) and is dispersed and suspended in the liquid phase mainly composed of the combustion improver (hereinafter, this state is referred to as "a/o (ammonia in oil) emulsion"), the amount of surfactant added is determined according to the volume fraction of liquefied ammonia in the ammonia-mixed fuel. Conversely, when the combustion improver becomes fine droplets (when the combustion improver is liquefied petroleum gas or its component hydrocarbons, a part of liquefied ammonia is dissolved in the liquid phase mainly composed of the combustion improver) and is dispersed and suspended in the liquid phase mainly composed of ammonia (hereinafter, this state is referred to as "o/a (oil in ammonia) emulsion"), the amount of surfactant added is determined according to the volume fraction (approximately mass fraction) of the combustion improver in the mixed fuel. The emulsion formed by the mixed surfactant used in Example 3 described above corresponds to this o/a emulsion. In general, the larger the volume fraction (approximately mass fraction) of the liquefied ammonia or combustion improver that becomes fine droplets and is dispersed and suspended in the mixed fuel, the larger the amount of surfactant that is generally required to be added. The amount of surfactant required varies depending on the type of surfactant, but when using a suitable surfactant (a high-performance mixed surfactant that is a mixture of nonionic and ionic surfactants) described below, as a guideline, a surfactant with a mass fraction of about 1/10 of the volume fraction (approximately mass fraction) of the liquefied ammonia or combustion improver to be dispersed or suspended in the mixed fuel is preferable for forming a stable emulsion. Usually, about 0.1 to 10 mass % is added to the ammonia mixed fuel.
In addition, when such a nonionic and ionic mixed surfactant is used in combination, it is possible to make the polar ammonia and the nonpolar feedstock hydrocarbon into either the a/o emulsion or the o/a emulsion. Furthermore, in order to preferentially form either of these, a surfactant that is particularly suitable for each of the emulsions can be appropriately selected or adjusted by blending. In general, when the volume of the separated liquid phase mainly composed of liquefied ammonia is smaller than the volume of the separated liquid phase mainly composed of the feedstock hydrocarbon, it is advantageous to form an a/o emulsion in terms of saving the amount of surfactant and dispersing it uniformly throughout, and therefore a surfactant that is more likely to form an a/o emulsion is selected or blended. In the opposite case, a surfactant that is more likely to form an o/a emulsion is selected or blended. However, the same surfactant may be selected or blended to be suitable for both a/o emulsification and o/a emulsification.

In the ammonia-mixed fuel of the above embodiment, a preferred surfactant is a mixed surfactant containing at least one nonionic surfactant (A) and at least one ionic surfactant (B). However, the terms "ionic" and "nonionic" herein are distinguished from each other by whether or not they have the property of ionizing in the environment of the ammonia-mixed fuel in a liquid state. The general terms "ionic" and "nonionic" are distinguished from each other by whether or not they ionize as hydrated ions in the presence of water. However, since the ammonia-mixed fuel of the present invention does not substantially contain water, the terms "ionic" and "nonionic" are distinguished from each other by whether or not they can ionize as ions solvated mainly by ammonia in the ammonia-mixed fuel. In addition, the ionization process may involve the transfer and exchange of H ⁺ or anionic species/cationic species between ionic and nonionic surfactant molecules, or between these surfactant molecules and ammonia molecules, and the above-mentioned "ionic" and "nonionic" are distinguished from each other by whether or not they ionize, including the series of processes.
In general, surfactants have the property that the surfactant molecules, which have two parts that show affinity to each of the two liquid phases, are arranged two-dimensionally at the interface between the two phases while the parts that have affinity to each of the two phases face each other. In order for such surfactants to exhibit the effect of emulsification, when either of the two separated liquid phases is divided into a large number of microdroplets by stirring and dispersed in the other phase, the surfactant molecules must be arranged two-dimensionally at the surface interface of all the microdroplets in the above manner and continue to cover the microdroplets (the formation of so-called "micelles"), and generate stable electrostatic repulsion between the microdroplets (micelles) so as to prevent the microdroplets (micelles) from contacting each other again and fusing again.

In the case of forming an emulsion between liquefied petroleum gas, naphtha, gasoline, kerosene, diesel, and their component hydrocarbons and water, there are many surfactants that can form emulsions by themselves, whether nonionic or ionic. However, when emulsifying an ammonia-mixed fuel containing liquefied ammonia and the feedstock hydrocarbon, the present inventor tried using representative nonionic and ionic surfactants that are generally available on the market by themselves, but the effect of emulsion formation was poor, and the mixture was separated into two layers as in the case of no additive. This is presumably because the polarity of ammonia is not as high as that of water, and the polarity difference between the feedstock hydrocarbon is smaller than that of the water-based system, and it is difficult for a single surfactant to achieve the above-mentioned two elements of covering the microdroplets by arranging them two-dimensionally at the surface interface of the microdroplets (forming micelles) and providing sufficient electrostatic repulsion between the micelles.
However, the present inventor has found that, as described below, by mixing and using several types of nonionic surfactants and several types of ionic surfactants in an appropriate ratio, it is possible to stably and satisfactorily emulsify an ammonia-mixed fuel containing liquefied ammonia and the feedstock hydrocarbons (liquefied petroleum gas, naphtha, gasoline, kerosene, diesel, and their component hydrocarbons). Here, the nonionic surfactant mainly contributes to the stable formation of an extremely thin film (film at the micelle interface) that covers the microdroplets while being two-dimensionally arranged at the surface interface of the microdroplets. On the other hand, the ionic surfactant mainly contributes to preventing recontact and refusion between the microdroplets by steadily ionizing itself while participating in the formation of the film by the nonionic surfactant, thereby imparting stable electrostatic repulsion to the surface interface of the microdroplets (micelles). In this way, when a suitable nonionic and ionic surfactants are mixed and used, the ammonia-mixed fuel can be satisfactorily emulsified by the synergistic effect of the above-mentioned respective contributions.
However, even if a nonionic surfactant suitable for membrane formation at the micelle interface or an ionic surfactant suitable for ionization repulsion is used alone, it is difficult to form a stable emulsion. That is, with the former alone, the electrostatic repulsion between the formed micelles is insufficient, and the transiently generated micelles repeatedly contact and fuse with each other, eventually re-separating into two phases. Moreover, with the latter alone, the film-forming ability at the two-phase interface is insufficient, making it difficult to form micelles themselves.
In addition, the category of "mixture of nonionic surfactant (A) and ionic surfactant (B)" in the above "suitable surfactant" includes not only a simple physical mixture of each surfactant, but also an embodiment using a surfactant having both nonionic and ionic polar sites in one surfactant molecule. Such surfactants also include copolymers in which the above-mentioned two types of polar sites, ionic and ionic, are polymerized. The molecular structure may be, for example, one having the above-mentioned suitable nonionic surfactant partial structure and the above-mentioned suitable ionic surfactant partial structure in series in the main chain, or one having the above-mentioned suitable nonionic surfactant partial structure and the above-mentioned suitable ionic surfactant partial structure in parallel as a side chain. In these, the quantitative ratio of the nonionic surfactant partial structure and the ionic surfactant partial structure is determined in accordance with the respective quantitative ratios that are suitable in the case of a simple physical mixture of the nonionic and ionic surfactants described above.

Among the above-mentioned preferred mixed surfactants, particularly preferred surfactants have the following features:
(A) In the molecular structure, a primary or secondary amino group [-NH ₂ or >NH], a polyoxyalkylene amino group [>N(C _a H _2a O) _c -H or -N((C _b H _2b O) _d -H) ((C _b H _2b O) _e -H)] (a and b are 2 or 3, c is an integer of 1 to 8, d and e are 0 or positive integers such that d+e=1 to 8), an amide group [-C(=O)NH ₂ ], a polyoxyalkylene amide group [-C(=O)N((C _f H _2f O) _g -H) ((C _f H _2f O) _h -H)] (f is 2 or 3, g and h are 0 or positive integers such that g+h=1 to 8), and a polyoxyalkylene group [-O(C _i at least one of the nonionic surfactants having at least one group selected from the group consisting of a alkyl group [C _k H _{2k + 1} -] (k is an integer of 7 to 18) and an alkenyl group [C _l H _2l-1 -] (l is an integer of 7 to 18) as a nonionic polar moiety;
(B) In its molecular structure, it has at least one of a quaternary methylammonium group, a quaternary methylalkanolammonium group, or a quaternary alkanolammonium group [-N ⁺ (CH ₃ ) _p (C _m H _2m OH) _q.X ^- , or >N ⁺ (CH ₃ ) _r (C _n H _2n OH) _s.X ' ^- ] (m and n are 2 or 3, p and q are 0 or positive integers such that p+q=3, r and s are 0 or positive integers such that r+s=2, and X and X' are any of Cl, Br and I) and a carboxyl group [-C(=O)OH] as an ionic polar site, and also has an alkyl group [C _t H _2t+1 - ] (t is an integer of 7 to 18) and an alkenyl group [C _u H _2u-1 and at least one of the ionic surfactants having at least one group as a non-polar moiety, such as at least one of the following:

In the above, (A) is a nonionic surfactant as a main component constituting a particularly suitable surfactant in an ammonia-blended fuel containing the nonpolar feedstock hydrocarbon as a combustion improver, and (B) is an ionic surfactant as a subcomponent constituting a particularly suitable surfactant. As described above, the nonionic surfactant (A) mainly contributes to the formation of a thin film in which the molecules are two-dimensionally arranged at the interface between two separated liquid phases, and micelles covered by said film, and the ionic surfactant (B) mainly contributes to the electrostatic repulsion between the micelles by ionizing in the film.
Among the above, the molecule of the nonionic surfactant (A) has, as a nonionic polar site, a primary or secondary amino group [-NH ₂ or >NH] having the same structure as ammonia (-N<), a polyoxyalkylene amino group [>N(C _a H _2a O) _c -H or -N((C _b H _2b O) _d -H) ((C _b H _2b O) _e -H)] (a and b are 2 or 3, c is an integer of 1 to 8, d and e are 0 or positive integers such that d+e=1 to 8), an amide group [-C(=O)NH ₂ ], and a polyoxyalkylene amide group [-C(=O)N((C _f H _2f O) _g -H) ((C _f H _2f O) _h Since these surfactants have either a polyoxyalkylene group [-O(CiH2iO)j-H] (i is 2 or 3, j is an integer from 1 to 8) containing a large amount of ether oxygen _{( -O-} ), the surfactants have a high affinity based on hydrogen bonds to liquefied ammonia or a liquid phase mainly composed of liquefied ammonia. These nonionic surfactants (A), including those in which the polar portion is an _amino group, hardly take part in ionization themselves in ammonia-mixed fuel that does not contain water (for this reason, they are classified as "nonionic"). In addition, the nonionic surfactant (A) also has a nonpolar long-chain alkyl group [C _k H _2k+1 -] or a long-chain alkenyl group [C _l H _2l-1 -] (k and l are integers from 7 to 18), and therefore has a high affinity for the feedstock hydrocarbon or the liquid phase mainly composed of feedstock hydrocarbons. Moreover, while commercially available surfactants may dissolve in either liquefied ammonia or the liquid phase mainly composed of liquefied ammonia, or the feedstock hydrocarbon or the liquid phase mainly composed of feedstock hydrocarbons, the above nonionic surfactant (A) has a low solubility in both liquid phases, probably due to the balance of its affinity, and is characterized in that it does not dissolve in either phase and tends to migrate to the interface between them.

In the case of forming an emulsion between liquefied ammonia or a liquid phase mainly composed of liquefied ammonia and a liquid phase mainly composed of feedstock hydrocarbons, the inventors' trials showed that a long-chain alkylamine having one long-chain alkyl group and a primary amino group (-NH ₂ ) [rational formula: C _k H _2k+1 NH ₂ ] (k is an integer of 7 to 18) showed the highest effect as a nonionic surfactant (A). Such long-chain alkylamines migrate to the interface between the two phases to form a membrane well, and as a result, micelles are also easily formed. Such long-chain alkylamine nonionic surfactants (A) can be used well in both the a/o emulsion and the o/a emulsion. In particular, they seem to be more likely to form the latter, and therefore are particularly effective in emulsifying a mixed fuel containing a large amount of liquefied ammonia and a relatively small amount of feedstock hydrocarbons.
Among the nonionic surfactants (A), those which exhibit a film-forming effect at the interface similar to that of the above-mentioned long-chain alkylamines when an emulsion is formed between liquefied ammonia or a liquid phase mainly composed of liquefied ammonia and a liquid phase mainly composed of raw material hydrocarbons are as follows:
long-chain alkyl polyoxyalkylene amine having one long-chain alkyl group and a polyoxyalkylene amino group [rational formula: C _k H _2k+1 N((C _b H _2b O) _d -H)((C _b H _2b O) _e -H)] (b is 2 or 3, d and e are 0 or positive integers such that d+e=1 to 8, and k is an integer from 7 to 18);
long-chain alkylamides having one long-chain alkyl group and an amide group [rational formula: C _k H _2k+1 -C(=O)NH ₂ ] (k is an integer of 7 to 18);
Long-chain alkyl polyoxyalkylene amides having one long-chain alkyl group and a polyoxyalkylene amide group [rational formula: _{CkH2k +1} -C(=O)N(( _CfH2fO ) _g -H)(( _CfH2fO ) _h -H)] ( _f is 2 or 3, g and _h are 0 or positive integers such that g+h=1 to 8, and k is an integer from 7 to 18), and
An example of such a copolymer is polyalkoxyethylene long-chain alkyl ether [rational formula: C _k H _2k+1 O(C _i H _2i O) _j -H] (i is 2 or 3, j is an integer from 1 to 8, and k is an integer from 7 to 18), which has one long-chain alkyl group and a polyoxyalkylene group.
Among the above, long-chain alkyl (and long-chain alkenyl) polyoxyalkylene amines, long-chain alkyl (and long-chain alkenyl) polyoxyalkylene amides, and polyalkoxyethylene long-chain alkyl (or long-chain alkenyl) ethers, which have a partial structure of a polyoxyalkylene group (polyether), may be particularly effective in forming an emulsion containing a raw material alcohol in addition to liquefied ammonia and a raw material hydrocarbon.

On the other hand, as the ionic surfactant (B), when an emulsion is formed between liquefied ammonia or a liquid phase mainly composed of liquefied ammonia and a liquid phase mainly composed of a feedstock hydrocarbon or a liquid phase mainly composed of a feedstock hydrocarbon, in the trials conducted by the present inventor, a quaternary long-chain alkyltrimethylammonium having one long-chain alkyl group and a trimethylammonium group [rational formula: C _k H _2k+1 N ⁺ (CH ₃ ) _3.X ⁻ ] (k is an integer of 7 to 18) showed the highest effect. The quaternary long-chain alkyltrimethylammonium ionizes at the boundary with the liquid phase mainly composed of liquefied ammonia while participating in the film formation at the interface by the nonionic surfactant (A), and therefore effectively prevents contact and fusion between micelles. Such an ionic surfactant (B) of quaternary long-chain alkyltrimethylammonium can be used effectively in both the formation of the a/o emulsion and the o/a emulsion. Like the above-mentioned long-chain alkylamines in the nonionic surfactant (A), they appear to have a tendency to form o/a emulsions in particular, and for this reason are particularly effective in emulsifying mixed fuels containing a large amount of liquefied ammonia and a relatively small amount of feedstock hydrocarbons.
In addition, an ionic surfactant (B) of long-chain alkylmethylalkanolammonium [C _{k H} 2k+1 N + (CH ₃ ) _p (C _m H _2m OH ₎ q.X - ] (k is an integer from 7 to 18, m is 2 or 3, p and q are 0 or positive integers such that _{p +q=3} , ^and _X is any of Cl, Br and I) having a quaternary ammonium group as a polar site in _which one to three methyl groups [-CH 3 ] of the trimethylammonium group are replaced with alkanol groups [C m ^H 2m OH] (m is 2 or 3), exhibits film formation and ionization effects at the interface similar to those of the surfactant having a trimethylammonium group when an emulsion is formed between liquefied ammonia or a liquid phase mainly composed of liquefied ammonia and a raw material hydrocarbon or a liquid phase mainly composed of a raw material hydrocarbon. Furthermore, these ionic surfactants (B) having a quaternary methylalkanol ammonium group may be particularly effective in forming an emulsion containing a raw material alcohol in addition to liquefied ammonia and a liquid raw material hydrocarbon.

Furthermore, an ionic surfactant (B) having a carboxyl group [—C(═O)OH] as a polar moiety can also be used favorably when forming an emulsion with the feedstock hydrocarbon or a liquid phase mainly composed of the feedstock hydrocarbon. For example, ionic surfactant (B) which is a long-chain alkyl carboxylic acid [rational formula: C _k H _2k+1 C(═O)OH] (k is an integer from 7 to 18) having a carboxyl group as a polar portion also participates in the film formation at the interface by nonionic surfactant (A), and at the boundary with the liquid phase mainly composed of liquefied ammonia, ionizes by donating H ⁺ to the coexisting ammonia (and the long-chain alkyl (or long-chain alkenyl) amine in (A)) [ionization formula: -C(═O)OH + NH ₃ (or C _k H _2k+1 NH ₂ , etc.) = -C(═O)O ^- + NH ₄ ⁺ (or C _k H _2k+1 NH ₃ ⁺ , etc.)], thereby electrostatically repelling the micelles and preventing them from contacting and fusing with each other. Furthermore, such an ionic surfactant (B) having a long-chain alkyl group or alkenyl group and a carboxyl group can form either the above-mentioned a/o emulsion or o/a emulsion, but is particularly likely to form the former, and is therefore particularly effective in emulsifying a mixed fuel containing a large amount of feedstock hydrocarbons and a relatively small amount of liquefied ammonia.
Further, there is (A) a long-chain dialkyl (or long-chain dialkenyl) amine having two long-chain alkyl or alkenyl groups and a secondary amino group [>NH] [the rational formula: (C _k H _2k+1 ) ₂ NH ₂ or (C _l H _2l-1 ) ₂ NH ₂ ] (k and l are integers of 7 to 18), or (B) a quaternary long-chain dialkyl or dialkenyl dimethyl ammonium having two long-chain alkyl or alkenyl groups and a dimethyl amino group [>N ⁺ (CH ₃ ) ₂ ·X ^- ] [the rational formula: (C _k H _2k+1 ) ₂ N ⁺ (CH ₃ ) _r (C _n H _2n OH) _s ·X' ^- or (C _l H _2l-1 ) ₂ N ⁺ (CH ₃ ) _r (C _n When ( ^B ) of the formula (H _2n OH) _s.X'- (n is 2 or 3, r and s are 0 or positive integers such that r+s=2, and X' is any of Cl, Br and I) is added in a small amount to (A) of the above-mentioned simple long-chain alkyl (or long-chain alkenyl) amine having one long-chain alkyl or alkenyl group and a primary amino group (-NH ₂ ), or (B) of the above-mentioned quaternary long-chain alkyltrimethylammonium having one long-chain alkyl or alkenyl group and a trimethylammonium group, it tends to form an O/A emulsion more easily.

The mixing ratio of the nonionic surfactant (A) to the ionic surfactant (B) in the above mixed surfactant system ((A) + (B)) is preferably in the range of about 0.7:0.3 to 0.9:0.1 in terms of molar ratio, and in particular, an emulsion is most favorably formed at a ratio of about 0.80:0.20 (see comparison of Examples 3 and 11 with Reference Examples 1 and 2 described later).
In addition, in the above, the carbon numbers k, l, t and u of the long-chain alkyl or alkenyl groups of the nonionic surfactant (A) and the ionic surfactant (B) are appropriately selected depending on the temperature at which the ammonia mixed fuel is prepared and stored. In general, the higher the temperature, the more suitable the carbon numbers are. For example, when the preparation and mixing temperature is near the liquefaction temperature of ammonia (-33°C) under atmospheric pressure (for example, about minus several tens of degrees Celsius), k, l, t and u are suitable to be about 7 to 8 in order to suppress solidification and precipitation of the surfactant at low temperatures. Also, when the temperature is near room temperature (25°C), for example, about 0 to 50°C, in order to achieve both stability of the arrangement at the separation liquid phase interface and fluidity, the carbon numbers of these are often about 10 to 14. At higher temperatures, generally more carbon numbers are suitable. Therefore, each surfactant has a temperature range suitable for expressing its function. On the other hand, the temperature at which the ammonia mixed fuel is prepared and stored is often selected depending on the type of combustion improver. For example, when the combustion improver is liquefied petroleum gas and its component hydrocarbons, it is preferable that the saturated vapor pressure is as low as possible from the viewpoint of the pressure resistance of the mixing vessel and ease of operation, and therefore the temperature of preparation and mixing is performed from the vicinity of the liquefaction temperature of ammonia under atmospheric pressure to the vicinity of room temperature (25°C), that is, about minus several tens of degrees Celsius to 50°C. Also, when the combustion improver is naphtha, gasoline, kerosene, and diesel, or their component hydrocarbons, the temperature of preparation and mixing is often selected from the viewpoint of the viscosity and stirring and mixing properties, such as the vicinity of room temperature (25°C), for example, about 0 to 50°C, or a temperature range higher than that. Also, when using a mixed surfactant of a plurality of chain lengths (carbon numbers) in which the chain lengths (carbon numbers k, l, t, and u) are distributed in a certain range, a more stable emulsion may be formed. For example, there is a specific distribution of the carbon numbers of long-chain alkyl groups derived from inexpensive coconut oil (k, t ≈ 8 to 18; generally, among these, k, t = 12 accounts for about 60% and is the most common), and mixed surfactants having these groups may be more likely to form stable emulsions.
Therefore, by selecting a surfactant having a long-chain alkyl group or an alkenyl group suitable for a temperature range according to the liquid phase composition to be emulsified as described above and maintaining the temperature range, at least a part of, or even the entire liquid phase portion of the ammonia mixed fuel becomes an emulsion state of the ammonia and the combustion improver, and the ammonia mixed fuel can be burned well.

In addition, the nonionic and ionic surfactants having the above molecular structures have high affinity based on hydrogen bonds to polar ammonia molecules (and also to raw material alcohol molecules having 3 or less carbon atoms that may be added), and have polar sites of moderate polarity in which the local structures of the atomic arrangements of the molecules are similar to each other.

Furthermore, the nonionic and ionic surfactants used in the above ammonia-mixed fuel do not have a molecular structure portion that has a problem with durability against the alkalinity exhibited by ammonia, and are chemically stable. On the other hand, it is not preferable that the molecular structure contains, for example, an ester group (-C(=O)-O-), a urethane group (-O-C(=O)-NH-), etc., which are easily deteriorated under alkaline conditions. In particular, when the combustor that burns the ammonia-mixed fuel is a reciprocating engine or the like having a moving part that requires sliding properties, it is preferable to avoid surfactants that generate by-products that become ash in the combustion gas and that can deteriorate the sliding properties when the mixed fuel is burned. For example, as the ionic surfactant, it is possible to use a surfactant whose polar site is, for example, a sulfonate salt (the polar site is -SO ₃ ^{-.Na +} , etc.), but in that case, ash containing sodium sulfate and the like generated after combustion is generated as a by-product that is disadvantageous in terms of sliding, and therefore it is not preferable as a surfactant to be used in the ammonia-mixed fuel of the present invention.
In Examples 3 to 12 described later, when n-butane, a component of liquefied petroleum gas, is used as a combustion improver and a predetermined amount of various mixed surfactants are added and mixed, the lower limit temperature at which the upper and lower two-phase separation state is eliminated by the formation of an emulsion (in this case, an O/A emulsion) and the saturated vapor pressure at that time are listed (the standard for comparison is Example 2, in which no surfactant is added). From these Examples, it can be seen that emulsification by adding a mixed surfactant can reduce the temperature required for solubilization, and therefore the rise in the saturated vapor pressure of the ammonia mixed fuel can also be suppressed. Therefore, emulsification by adding these mixed surfactants increases the amount of the combustion improver n-butane soluble in ammonia at a predetermined temperature, and also reduces the required pressure resistance of the storage container during storage.

(Production apparatus and production method for ammonia-mixed fuel)
FIG. 2 is a diagram showing an example of the configuration of an apparatus for producing an ammonia mixed fuel according to an embodiment.
The manufacturing apparatus 10 shown in FIG. 2 is an apparatus for manufacturing an ammonia-mixed fuel in the case where the combustion improver is liquefied petroleum gas and the component hydrocarbon species of the liquefied petroleum gas. The liquefied petroleum gas and the hydrocarbon species contained as its components are preferable in that they generate less CO ₂ per calorific value when burned, compared with the liquid fossil fuels that have been widely used in the past, such as gasoline, kerosene, light oil, or heavy oil. In addition, the liquefied petroleum gas and its component hydrocarbon species have a saturated vapor pressure close to that of ammonia in the liquid state at the same temperature, and are easy to ignite because they have a lower ignition temperature than ammonia, and also have a higher burning speed than ammonia (about 5 to 6 times that of ammonia in laminar burning speed), making them easy to burn. For this reason, the liquefied petroleum gas and the hydrocarbon species contained as its components are preferable as a combustion improver for ammonia. An ammonia-mixed fuel containing such a combustion improver can be manufactured by the manufacturing apparatus 10 shown in FIG. 2.
The manufacturing apparatus 10 mainly includes an ammonia storage sealed container 12, a combustion improver storage sealed container 14, a mixing sealed container 16, an ammonia introduction line 18, a combustion improver introduction line 20, a gas phase discharge line 21, a liquid phase discharge line 22, an agitator 24, a thermometer 33, and a pressure gauge 31. In addition, the manufacturing apparatus 10 shown in FIG. 2 includes a surfactant storage container 26, a surfactant introduction line 28, a nitrogen gas introduction mechanism 30, flowmeters 18a, 20a, 28a, regulating valves 18b, 20b, 28b, 18c, 20c, 28c, and a control device 32. The regulating valves 18c, 20c, 28c are inlet valves that introduce raw materials into the mixing sealed container 16. Furthermore, the mixing sealed container 16 is provided with a temperature control jacket 17 for controlling the temperature inside the mixing sealed container 16, a temperature control medium inlet nozzle 17a at the bottom, and a temperature control medium outlet nozzle 17b at the top.

The ammonia-storage sealed container 12 is a cylinder or tank that stores ammonia in a liquid state (liquefied ammonia).
The combustion improver storage sealed container 14 is a cylinder or tank for storing a liquid combustion improver that assists the combustion of ammonia. As described above, the combustion improver here is at least one of (a) liquefied petroleum gas and (b) a feedstock hydrocarbon, which is at least one type of hydrocarbon contained as a component in the liquefied petroleum gas.

The mixing sealed container 16 is provided with an agitator 24. The mixing sealed container 16 is configured so that a dissolved solution state or an emulsified mixture is obtained by agitating and mixing liquid ammonia and a combustion improver with the agitator 24, and the mixture obtained by agitating and mixing with the agitator can maintain a gas-liquid equilibrium state. Specifically, the mixing sealed container 16 has a pressure-resistant structure and is airtight so that the saturated vapor pressure of the ammonia, the combustion improver, and the mixture thereof can be maintained inside the mixing sealed container 16.

The ammonia introduction line 18 is provided with a flowmeter 18a and regulating valves 18b, 18c configured to introduce a predetermined amount into the ammonia storage sealed container 12 and the mixing sealed container 16 as an ammonia quantitative introduction mechanism. The control device 32 receives the measurement result of the ammonia flow rate by the flowmeter 18a, generates a control signal for controlling the opening degree of the regulating valves 18b, 18c, and sends the generated control signal to the regulating valves 18b, 18c. During the quantitative introduction, when the control device 32 determines that the time integral value of the ammonia flow rate from the start of the introduction of ammonia has reached the set amount to be introduced into the mixing sealed container 16, the regulating valves 18b, 18c are fully closed by the control signal generated by the control device 32, and the introduction is stopped.
As the flow meter 18a, for example, a flow meter that determines the flow rate from the floating height of a float that floats due to the upward flow of the fluid in the piping of the ammonia introduction line 18, a critical nozzle type or thermal type flow sensor type mass flow meter or mass flow controller, an ultrasonic flow meter, a Coriolis type flow meter, or the like is used. In this case, the amount of ammonia introduced can be determined by the time integration of the flow rate measurement value from the start to the end of the introduction of ammonia.
Instead of the flowmeter 18a in Fig. 2, a weighing machine (not shown) for weighing the weight of the mixing closed vessel 16 may be provided separately, and the amount of ammonia introduced may be controlled based on the weighing value of the weighing machine associated with the introduction of liquefied ammonia into the mixing closed vessel 16. However, this control method cannot be applied to the case of continuous production of ammonia mixed fuel with a constant composition by continuous introduction of raw ammonia and combustion improver as shown in Fig. 5 described later. In that case, the ammonia quantitative introduction mechanism is composed of the weighing machine and the regulating valves 18b and 18c. When introducing a fixed amount of ammonia, the control device 32 receives the weighing result by the weighing machine, generates a control signal for controlling the opening degree of the regulating valves 18b and 18c, and sends the generated control signal to the regulating valves 18b and 18c. During the introduction of a fixed quantity, when the control device 32 determines that the weighing result of the amount of ammonia introduced (the value obtained by subtracting the mass of the mixing sealed container 16 before the start of the introduction of ammonia) has reached the set amount to be introduced into the mixing sealed container 16, the control device 32 generates a control signal to fully close the adjustment valves 18b, 18c and stop the introduction.

The combustion improver introduction line 20 connects the combustion improver storage sealed container 14 and the mixing sealed container 16. The combustion improver introduction line 20 is provided with a flowmeter 20a and regulating valves 20b, 20c configured to introduce a predetermined amount of the combustion improver from the combustion improver storage sealed container 14 to the mixing sealed container 16 as a combustion improver quantitative introduction mechanism. The flowmeter 20a has a mechanism similar to that of the liquefied ammonia flowmeter 18a. The control device 32 receives the measurement result by the flowmeter 20a, generates a control signal for controlling the opening degree of the regulating valves 20b, 20c, and sends the generated control signal to the regulating valves 20b, 20c. When the control device 32 determines that the time integral value of the flow rate of the combustion improver from the start of the introduction of the combustion improver has reached the set amount to be introduced into the mixing sealed container 16, the regulating valves 20b, 20c are fully closed by the control signal generated by the control device 32, and the introduction is stopped.
Also, as in the case of introducing liquefied ammonia, it is possible to grasp and control the amount of the combustion improver introduced from the weighing value of the weighing machine (not shown) that weighs the weight of the mixing sealed container 16 instead of the flowmeter 20a. However, this control method cannot be applied to the case of continuous production of ammonia mixed fuel with a constant composition by continuous introduction of raw ammonia and combustion improver as shown in FIG. 5 described later. In that case, the combustion improver fixed amount introduction mechanism is composed of the weighing machine and the regulating valves 20b, 20c. When introducing a fixed amount, the control device 32 receives the weighing result of the combustion improver by the weighing machine, generates a control signal for controlling the opening degree of the regulating valves 20b, 20c, and sends the generated control signal to the regulating valves 20b, 20c. When introducing a fixed amount, when the control device 32 determines that the weighing result of the amount of combustion improver introduced (the value minus the mass of the mixing sealed container 16 before the introduction of the combustion improver started) has reached the set amount to be introduced into the mixing sealed container 16, the control signal generated by the control device 32 fully closes the adjustment valves 20b, 20c and stops the introduction.
The saturated vapor pressure of ammonia in a liquid state and the saturated vapor pressure of the combustion improver, which is liquefied petroleum gas or a component hydrocarbon of liquefied petroleum gas, are both considerably higher than atmospheric pressure at around room temperature (25° C.). Therefore, if the internal pressure of the mixing sealed container 16 is about atmospheric pressure and sufficiently lower than these saturated vapor pressures, as shown in FIG. 2, even if a liquid feed pump is not provided in the ammonia introduction line 18 and the combustion improver introduction line 20, they can be introduced into the mixing sealed container 16 by discharging the liquid phase due to the saturated vapor pressure inside the ammonia storage sealed container 12 and the combustion improver storage sealed container 14.

The nitrogen gas introduction mechanism 30 is provided to replace the gas present in each introduction line and the mixing sealed container 16 with nitrogen gas as necessary from the viewpoint of explosion prevention, such as when starting up the production apparatus 10 and after the end of the production of ammonia mixed fuel. The nitrogen gas introduction mechanism 30 is provided with a nitrogen gas introduction valve 30a for introducing a predetermined amount of nitrogen gas into the ammonia introduction line 18 and the combustion improver introduction line 20. The opening degree of the nitrogen gas introduction valve 30a is controlled by a control signal generated based on a control signal that the control device 32 uses to control the opening degrees of the adjustment valves 18b, 18c, 20b, and 20c.
The introduction of liquefied ammonia and the combustion improver, which is a component hydrocarbon of liquefied petroleum gas, into the mixing sealed container 16 is preferably carried out in the following manner. When introducing these liquefied gases, ammonia and the combustion improver, they can be introduced into the mixing sealed container 16 by being discharged at their respective saturated vapor pressures in the respective storage sealed containers (12, 14). In this case, in order to complete the introduction of both, the saturated vapor pressure of the mixture of the two in the mixing sealed container 16 must always be lower than the internal pressure of the ammonia storage sealed container 12 (saturated vapor pressure of ammonia) and the internal pressure of the combustion improver storage sealed container 14 (saturated high pressure of the combustion improver) during the introduction. For this reason, before a series of introduction steps, the temperature of the liquid phase of the mixture in the mixing sealed container 16 is maintained at a predetermined temperature such that the saturated vapor pressure is sufficiently low (for example, about 0.05 to 0.1 MPa or less) by temperature control described later (in many cases, it is cooled to a temperature lower than the external environment).
After that, the gas phase exhaust valve 21a is opened (opened to the atmosphere), and a predetermined amount of nitrogen gas is passed through each introduction line into the mixing sealed container 16 by the nitrogen gas introduction mechanism 30, and the air in each introduction line and the mixing sealed container 16 is replaced with nitrogen gas once from the viewpoint of explosion prevention, as necessary. Next, the above-mentioned quantitative introduction mechanism sequentially introduces predetermined amounts of liquefied ammonia, combustion improver, and surfactant into the mixing sealed container 16 through each introduction line. During these introductions, in order to avoid a situation in which the internal pressure of the mixing sealed container 16 rises and it becomes impossible to introduce any more liquefied ammonia, combustion improver, etc., as described later, the order of introduction is basically preferably from the one with the lowest saturated vapor pressure at the temperature during stirring and mixing in the mixing sealed container 16, as described later. Among the raw materials of liquefied ammonia as a liquefied gas, liquefied petroleum gas as a combustion improver, and its component hydrocarbon species, they are introduced into the mixing sealed container 16 in the order of the lowest saturated vapor pressure at the set temperature. Here, for example, between ammonia and propane, one of the components of liquefied petroleum gas, the saturated vapor pressure of propane is higher than that of ammonia at temperatures below about 15°C, and the order of introduction must be selected with attention being paid to the fact that the saturated vapor pressure of propane is higher than that of ammonia at temperatures above that temperature. In this case, it is preferable that the nitrogen gas that filled the inside of the mixing sealed container 16 is sufficiently removed and replaced by the vaporized gas of the liquefied gas component with the lowest saturated vapor pressure, which is introduced first among the liquefied gas raw materials. After this gas replacement, the gas phase discharge valve 21a is closed, and the regulating valves 18b, 18c or the regulating valves 20b, 20c are opened, and at the same time, the measurement of the introduction amount (time integral value of the flow rate) of the liquefied gas raw material introduced first is started, and after the introduction of the predetermined amount is completed, the regulating valves 18b, 18c or the regulating valves 20b, 20c are closed. When the second and subsequent liquefied gas raw materials are introduced, the above-mentioned gas replacement is not performed, and the remaining liquefied gas raw materials are introduced in the same manner in order of the lowest saturated vapor pressure.

According to the above configuration and procedure, even if the ammonia introduction line 18 and the combustion improver introduction line 20 are not provided with a liquid feed pump, the ammonia and the combustion improver can be introduced into the mixing sealed container 16, which has a lower internal pressure, by the discharge due to the saturated vapor pressure of the liquefied ammonia and the liquefied petroleum gas or the combustion improver, which is a component hydrocarbon of the liquefied petroleum gas, in the respective storage sealed containers 12 and 14. However, there are also cases where it is advantageous to be able to introduce the raw material ammonia and the combustion improver under pressure into the mixing sealed container 16, into which the ammonia and the combustion improver have already been introduced, against the saturated vapor pressure of the mixture of ammonia and the combustion improver (in many cases, the saturated vapor pressure of the mixture is higher than the saturated vapor pressure of the ammonia and the combustion improver alone). In particular, as described below, in cases where ammonia and the combustion improver are continuously additionally introduced in a fixed amount into the mixing sealed container 16 to continuously produce an ammonia-mixed fuel, etc., the ammonia introduction line 18 and/or the combustion improver introduction line 20 must each be provided with a liquid feed pump. In this case, the liquid feed pump is required to have a head sufficiently higher than the saturated vapor pressure of the mixture of ammonia and the above-mentioned combustion improver in the mixing sealed container 16, a sufficient discharge amount corresponding to the production speed and discharge speed of the ammonia mixed fuel, and the discharge amount is variable, and in addition to a high-head centrifugal pump, a volumetric type such as a gear type, screw type, plunger type, or uniaxial eccentric screw type is appropriately selected. Note that, when such a high-head liquid feed pump is provided in the ammonia introduction line 18 and the combustion improver introduction line 20, it is also possible to forcefully introduce ammonia and the combustion improver into the mixing sealed container 16 without following the above-mentioned introduction order.
When the liquid feed pump is provided in the ammonia introduction line and/or the combustion improver introduction line, each liquid feed pump is also driven or stopped in conjunction with the regulating valves 18b, 18c and/or the regulating valves 20b, 20c. At this time, when the liquid feed pump is a non-positive-displacement centrifugal pump or the like, the opening degree of each of the above-mentioned regulating valves is adjusted to control the liquid feed amount. On the other hand, when a positive-displacement liquid feed pump such as the above-mentioned vane type, gear type, screw type, plunger type, or uniaxial eccentric screw type is used, the opening degree of each of the above-mentioned regulating valves is almost fully opened during liquid feed, and the rotation speed of the motor of the liquid feed pump itself is controlled to be a predetermined discharge amount. After the series of introductions described above is completed, the control valves 18b, 18c, 20b, and 20c are all closed, and the mixing closed vessel 16 is put into a sealed state, the liquid phase temperature of the mixture in the mixing closed vessel 16 is switched by a temperature control mechanism described later from the predetermined temperature at the time of introduction for lowering the saturated vapor pressure to a temperature range preferable for the production of ammonia mixed fuel described later, and the temperature is preferably maintained throughout the subsequent production of ammonia mixed fuel. The series of controls described above are performed based on control signals generated by the control device 32.

The liquid phase discharge line 22 is usually provided at the lower part, preferably at the bottom, of the mixing closed vessel 16, and is configured so that substantially the entire amount of the mixture obtained by the stirring and mixing of the agitator 24 can be discharged from the mixing closed vessel 16 as an ammonia mixed fuel.
However, when the combustion improver is liquefied petroleum gas, naphtha, gasoline, kerosene, diesel, or a component hydrocarbon of these, the liquid phase of the mixture with ammonia in the mixing sealed vessel 16 may separate into upper and lower two layers. At this time, the lower liquid phase portion separated due to the difference in specific gravity is discharged from the liquid phase discharge line 22 provided at the bottom of the mixing sealed vessel 16 as shown in FIG. 2.
On the other hand, as a modification of the manufacturing apparatus 10 shown in Fig. 2, the liquid phase discharge line ₂₂₂ can be extended upward from the bottom of the mixing sealed container so that the opening of the upper end of the piping is slightly above the upper and lower layer interface, as shown in Fig. 3(a), to separately discharge the upper liquid phase portion. That is, the liquid phase discharge line of the manufacturing apparatus 10 includes both the form of ₂₂ in Fig. 2 and the form of 222 in Fig. 3, and further includes one having _both 221 and ₂₂₂ as shown in Fig. 3(b). These liquid phase discharge lines 22, ₂₂₁ , ₂₂₂ are provided with regulating valves 22a, _22a1 , _22a2 , and the openings of the regulating valves 22a, _22a1 , _22a2 are controlled by control signals from the control device 32. Note that Figs. 3(a) and 3(b) show only the parts of the manufacturing apparatus 10 related to the above configuration, and the other parts are omitted.

As the agitator 24 provided in the mixing sealed container 16, if the liquid ammonia and the combustion improver are compatible with each other by simple mixing without adding a surfactant, a general single-type agitator blade type is sufficient. However, if an emulsion is formed by adding a surfactant, the above-mentioned single-type agitator blade type may be applicable, but it is more effective to use a single or double planetary (planetary rotation) type agitator blade type, ultrasonic irradiation type, or a type that forcibly pressurizes and circulates the liquid mixture to be agitated in a narrow space, which have a higher dispersion effect. If a type of agitator with a high agitation effect is used, it becomes easier to form an emulsion state, but the internal pressure may increase due to heat generation caused by viscous friction of the liquid mixture to be agitated. This inconvenience can be eliminated by adjusting the temperature inside the mixing sealed container 16 using a series of temperature adjustment mechanisms in the embodiment described below.

In the manufacturing apparatus 10 according to one embodiment, a temperature control mechanism is provided that is configured to control the temperature of the mixture of ammonia and combustion improver in the mixing closed vessel 16 to a predetermined temperature. This temperature control mechanism can achieve the following three functions.
As a first function of the temperature control mechanism, when liquid ammonia, liquefied petroleum gas and its component hydrocarbon combustion improver are introduced into the mixing sealed vessel 16 and stirred and mixed by the agitator 24, the liquid phase temperature of the mixture is controlled so that the internal pressure of the mixing sealed vessel 16 (if the nitrogen in the gas phase has been sufficiently replaced in advance by the vaporized gas components of the raw material ammonia or the combustion improver, the internal pressure will be equal to the saturated vapor pressure of the mixture) is within a temperature range that does not exceed the set withstand pressure of the mixing sealed vessel 16. In other words, the liquid phase temperature of the mixture is controlled so that the saturated vapor pressure of the mixture in the mixing sealed vessel 16 does not exceed the set withstand pressure of the mixing sealed vessel 16. As a result, the saturated vapor pressure of the mixture at the highest expected mixing temperature can be set as the design pressure resistance of the mixing sealed vessel 16 (generally, a pressure value with a safety margin added is adopted), and there is no need to unnecessarily increase the pressure resistance of the mixing sealed vessel 16 any further, so that the mixing sealed vessel 16 and the manufacturing apparatus 10 are lighter and less expensive. In addition, once the liquid phase composition of the mixture in the mixing sealed vessel 16 is determined, there is a uniform relationship between the saturated vapor pressure and temperature of the mixture based on gas-liquid equilibrium (the relationship between the saturated vapor pressure and temperature is generally expressed with good accuracy by an approximation formula such as the Antoine formula, for example). The above pressure resistance design can be applied to the case where, in addition to the above-mentioned liquefied petroleum gas or its component hydrocarbons, naphtha, gasoline, kerosene, light oil, and their component hydrocarbons or raw material alcohol, which will be described later, are used as the combustion improver, and further, when a combination of a plurality of these is used as the combustion improver, and the mixing sealed vessel 16 and the manufacturing apparatus 10 are similarly lighter and less expensive.
The temperature control mechanism includes, in addition to the agitator 24, a thermometer 33, a pressure gauge 31, a temperature control jacket 17, and a thermostatic bath equipped with a heating and cooling mechanism for the temperature control medium m and a circulation pump for the temperature control medium m. The thermostatic bath is installed outside the manufacturing apparatus 10 and is not shown in FIG. 2. As the temperature control medium m, an inert liquid that is unlikely to solidify or volatilize in the controlled temperature range, such as water, ethylene glycol, diethylene glycol, etc., is selected. In FIG. 2, the temperature control jacket 17 is a heat exchanger that covers the outer periphery of the mixing sealed container 16, and the liquid temperature control medium m adjusted to a predetermined temperature flows inside the jacket 17, and the outer periphery of the mixing sealed container 16 is heated or cooled, so that the temperature of the mixture of ammonia and combustion improver inside the mixing sealed container 16 is adjusted to a target temperature by heat exchange. The temperature control medium m is adjusted to a predetermined temperature in the thermostatic bath, and flows into the temperature control medium inlet nozzle 17a provided at the bottom of the jacket 17 via a pipe (not shown), and after heat exchange, is discharged from the temperature control medium outlet nozzle 17b provided at the top of the jacket 17 and returns to the thermostatic bath via a pipe (not shown). When adjusting the temperature of the mixture inside the mixing sealed vessel 16, the agitator 24 is driven at a predetermined output based on a control signal for the agitator 24 generated by the control device 32, and the mixture in the mixing sealed vessel 16 is stirred. At the same time, the temperature adjustment of the thermostatic bath is operated based on the control signal generated by the control device 32, and the temperature control medium m adjusted in temperature in the thermostatic bath flows into the jacket 17 and is circulated to the thermostatic bath. During the temperature adjustment of the mixture, the stirring and circulation of the temperature control medium m are continued, and the liquid phase temperature near the gas-liquid interface in the mixing sealed container 16 is measured over time by a thermometer 33, and the gas phase internal pressure in the temperature control jacket 17 is measured over time by a pressure gauge 31. The control device 32 receives the measurement results from the thermometer 33 and the pressure gauge 31 over time.

The second function of the temperature control mechanism is to control the gas phase internal pressure and liquid phase temperature of the mixture in the mixing sealed vessel 16 as follows, so that the introduction of ammonia and a combustion improver into the mixing sealed vessel 16 proceeds smoothly. For example, in a series of processes of introducing liquefied gas raw materials into the mixing sealed vessel 16, as described above, the gas phase internal pressure (saturated vapor pressure) of the mixture of liquefied gas raw materials already introduced into the mixing sealed vessel 16 must be always kept lower than the lowest pressure value among the saturated vapor pressures in the respective storage sealed vessels of the individual raw materials liquefied ammonia, liquefied petroleum gas, and their component hydrocarbons to be introduced, and the liquid phase temperature is adjusted to a temperature required for this purpose or lower. In addition, in the process of producing an ammonia-mixed fuel by stirring and mixing after the introduction of the raw materials into the mixing sealed vessel 16 is completed, it is preferable that the liquid phase of the mixture of raw materials in the mixing sealed vessel 16 is kept in a preferred temperature range described later. In these temperature adjustments, the temperature of the temperature adjustment medium m flowing into the temperature adjustment jacket 17 is adjusted by controlling the output of the heating/cooling power of the thermostatic bath based on a control signal generated by the control device 32 so that the difference between the control target value of the gas phase internal pressure in the mixing sealed container 16 and the actual internal pressure measured by the pressure gauge 31, or the difference between the control target temperature value of the mixture and the actual temperature value measured by the thermometer 33, is within a respective set allowable range (for example, within ±0.01 MPa for the former, within ±1°C for the latter).
In order to improve the response speed and accuracy of the temperature control mechanism, it is preferable that the relationship between the gas phase internal pressure or liquid phase temperature of the mixture inside the mixing sealed container 16 after temperature control and the temperature of the temperature control medium m in the thermostatic chamber is recognized in advance by the control device 32, and the output of heating and cooling power of the thermostatic chamber is controlled by using a PID control or the like for the temperature of the temperature control medium m in the thermostatic chamber by a control signal generated by the control device 32 based on the relationship. In addition, in the process of these controls, if the control device 32 judges that the measured value of the gas phase internal pressure of the mixing sealed container 16 by the pressure gauge 31 is likely to reach the design pressure resistance of the mixing sealed container 16 due to some unexpected situation, the temperature control medium m is appropriately quenched in the thermostatic chamber or the circulation of the temperature control medium m by the thermostatic chamber is stopped based on the control signal generated by the control device 32 (the latter is effective when the temperature of the temperature control medium m is higher than the temperature of the surrounding environment), thereby preventing the internal pressure from increasing further.
In the above, on the premise of ensuring safety such as explosion prevention, instead of regulating the temperature inside the mixing sealed container 16 by heat exchange with the temperature control medium m in the temperature control jacket 17, for example, a Peltier element or a combination of a Peltier element and an electric heater may be provided on the outer periphery of the mixing sealed container 16 (not shown in FIG. 2 ) to regulate the temperature. In this case, the temperature inside the mixing sealed container 16 is regulated by controlling the heating or cooling output by the Peltier element or the like based on a control signal generated by the control device 32 which receives the internal temperature value measured by the thermometer 33.

As a third function of the temperature control mechanism, in the manufacturing apparatus 10 according to another preferred embodiment, after the introduction of ammonia and a combustion improver into the mixing sealed container 16, the temperature of the mixture is controlled by the temperature control mechanism so that the entire liquid phase part of the mixture of ammonia and a combustion improver in the mixing sealed container 16, which maintains a gas-liquid equilibrium state, is in a temperature range in which the ammonia and the combustion improver are dissolved in each other, or in an emulsion state of the ammonia and the combustion improver, depending on the liquid phase composition of the mixture. As a result, the entire mixture becomes an ammonia mixed fuel in which the combustion improver is stably and uniformly dispersed, and if this is burned in this state, uniform vaporization occurs as a whole, as described above, and subsequent uniform and high-speed combustion becomes possible. The above-mentioned temperature control for dissolving the entire liquid phase or for stabilizing and homogenizing the ammonia-mixed fuel by emulsifying it can be applied to the case where naphtha, gasoline, kerosene, diesel, and their component hydrocarbons, or raw material alcohol, which will be described later, are used as the combustion improver, in addition to the above-mentioned liquefied petroleum gas and its component hydrocarbons, and further, when a combination of a plurality of these is used as the combustion improver, and the combustibility can be improved in the same way.
In the above, the "temperature range in which the ammonia and the combustion improver are in a solution state in which they are dissolved in each other, or in which the ammonia and the combustion improver are in an emulsion state" is selected as an appropriate temperature range depending on the type of combustion improver and the liquid phase composition of the mixture, and is adjusted to be within that temperature range by the temperature control mechanism. In the case where the combustion improver is liquefied petroleum gas or its component hydrocarbons, the above temperature range will be explained below using an ammonia-propane system at 20°C as an example, which shows the phase equilibrium relationship of the azeotropic liquid two-phase separation in Figure 1(a).

For example, as described above, the ammonia mixed fuel in the mixing sealed container 16 becomes a gas-liquid equilibrium system having a composition range in which the liquid phase separates into two phases in a relatively low temperature range below the critical solution temperature (about 33°C in the case of an ammonia-propane mixed system). As described above, each of the two separated phases is in a single "solution state in which ammonia and a combustion improver are dissolved in each other", and if at least one of the two phases can be taken out to the outside, it becomes an ammonia mixed fuel in which the combustion improver is stably and uniformly dispersed. Since both of these two phases can be taken out to the outside by the configuration described later, if the temperature range corresponds to the liquid phase composition in such a two-phase separation state, it is included in the above-mentioned "temperature range in which ammonia and a combustion improver are dissolved in each other, or an emulsion state of ammonia and a combustion improver is formed".
As described above, in a mixture of ammonia and liquefied petroleum gas or its component hydrocarbon species, there is a temperature at which the entire liquid phase becomes a single-phase solution when the temperature exceeds a certain predetermined temperature. For example, as shown in FIG. 1(a) above, in the ammonia-propane mixture, at both compositions at points A and B (ammonia concentrations x _A =16.2 mass% and x _B =86.5 mass%), the entire solution becomes a homogeneous solution by being maintained at 20° C. or higher, and if this is to be taken out as a single phase, this temperature or higher is the above-mentioned "temperature range in which ammonia and the combustion improver are in a solution state in which they are dissolved together, or in an emulsion state between ammonia and the combustion improver". Furthermore, in a temperature range above the critical solution temperature (about 33° C. in the case of an ammonia-propane mixture), the composition range in which phase separation occurs disappears, and the mixture becomes a homogeneous solution at any liquid phase composition, which can be taken out. Therefore, the temperature range above the critical solution temperature is "a temperature range in which ammonia and the combustion improver are in a solution state in which they are dissolved in each other, or in which ammonia and the combustion improver are in an emulsion state", regardless of the composition.
Furthermore, for example, in the composition at point C in the ammonia-propane mixed system shown in FIG. 1(a) (ammonia concentration x _C =77% by mass), as described above, when about 1% by mass of a suitable mixed surfactant (same as that used in Example 3) is added and stirred and mixed, and the temperature is maintained at about 17° C. or higher, the phase separation portion is emulsified and disappears, and the whole can be made uniform. When no surfactant is added, the solution is made uniform at 23° C. In addition, the specifications and operating method of the manufacturing apparatus 10 when a surfactant is used will be described later. Therefore, in the composition at point C in the figure (ammonia concentration 77% by mass), when a predetermined amount (about 1% by mass) of the above-mentioned suitable mixed surfactant is added, about 17° C. or higher becomes the above-mentioned "temperature range in which the ammonia and the combustion improver are in a solution state in which they are dissolved together, or the ammonia and the combustion improver are in an emulsion state." At this time, it is preferable to select the mixed surfactant that exhibits the best performance in this temperature range. In other words, if such a surfactant is selected, the above-mentioned temperature range also coincides with the temperature range in which the emulsifying performance of the surfactant can be fully exhibited.
The homogeneous ammonia-mixed fuel produced in the above-described "temperature range in which the ammonia and the combustion improver are in a solution state in which they are dissolved in each other, or in an emulsion state between the ammonia and the combustion improver" according to the composition is taken out in that state and subjected to combustion, and exhibits high combustibility.

Next, the composition change state due to the liquid phase temperature of the ammonia-liquefied petroleum gas (or component hydrocarbon species of liquefied petroleum gas) ammonia mixed fuel, which is stirred and mixed while the liquid phase temperature is constantly controlled by the temperature control mechanism in the sealed mixing vessel 16 in Figure 2 and discharged from the liquid phase discharge line 22, will be explained below using the gas-liquid-liquid equilibrium of the ammonia-propane system at 20°C in the above-mentioned Figure 1 (a) as an example. Even when other component hydrocarbon species of liquefied petroleum gas, whose mixture with ammonia is also an azeotropic system with liquid phase separation, is used as a combustion improver, the situation is qualitatively similar, although there are differences in the temperature range, pressure range, and composition range.

(i) In the case of a liquid phase composition in which the liquid phase is a single phase In the gas-liquid-liquid equilibrium diagram at 20°C in Fig. 1( _a ) described above, there are two regions in which the liquid phase becomes a single-phase solution: a region between points P and A in which the liquid phase ammonia concentration is 0 mass% to _xA and is mainly composed of propane, and a region between points B and Q in which the liquid phase ammonia concentration is xB to 100 mass% and is mainly composed of ammonia. By introducing liquefied ammonia and liquefied propane into the mixing closed vessel 16 at the corresponding charging composition ratios and stirring and mixing, a single-phase ammonia mixed fuel having the liquid phase composition in the above two regions is prepared. This can be discharged from the liquid phase discharge line 22 by discharge based on the saturated vapor pressure in the mixing closed vessel 16.
However, it should be noted that as the discharge proceeds, the composition of the single-phase ammonia mixed fuel changes as follows. In the following, for simplicity, it is assumed that sufficient stirring and mixing of the liquid phase continues even during discharge, the composition and temperature of the entire liquid phase are always uniform, and the liquid phase temperature does not change. In reality, the liquid phase temperature drops somewhat as the liquid phase is discharged due to the endotherm associated with evaporation, which will be described later, but this is compensated for by the temperature control mechanism described above.

For example, when discharging an ammonia mixed fuel mainly composed of propane, in which the liquid phase ammonia concentration at the start of discharge is the saturated concentration _xA , which corresponds to point A in Fig. 1(a), the gas-liquid interface drops as the discharge proceeds, increasing the volume of the gas phase, and the pressure inside the mixing closed vessel 16 is reduced. In response to this change, the mixture of ammonia and propane evaporates (boils) from the liquid phase to the gas phase side by the increase in the gas phase volume inside the mixing closed vessel 16, dynamically maintaining the gas-liquid equilibrium. The composition of the evaporated gas that is in equilibrium with the liquid phase composition _xA at the start of discharge is the azeotropic composition _yO , which has a higher ammonia concentration than _xA , so that a relatively larger amount of ammonia evaporates from the liquid phase, and the ammonia concentration in the liquid phase drops somewhat from _xA . As the discharge of the ammonia-mixed fuel further progresses, the state of the liquid phase in the mixing closed vessel 16 changes so as to move on the liquidus line AP from point A (ammonia concentration x _A ) in Fig. 1(a) at the start of the discharge toward point P of pure propane (ammonia concentration 0 mass%), and accordingly, the state of the gas evaporating into the gas phase side changes so as to move on the gasus line OP from point O (ammonia concentration y _O ) in Fig. 1(a) toward point P of pure propane. During this process, the internal pressure in the mixing closed vessel 16 decreases from the azeotropic vapor pressure at point O toward the saturated vapor pressure of pure propane at point P as the liquid phase is discharged.
In addition, when discharging an ammonia-mixed fuel having a liquid phase ammonia concentration between 0 mass % and _xA , the above operation is equivalent to starting from a point midway between the liquid phase line AP and the gas phase line OP.
On the other hand, when discharging an ammonia-based ammonia-mixed fuel in which the liquid-phase propane concentration at the start of discharge is 1- _xB , which corresponds to point B in Fig. 1(a), the following state change is shown. That is, as the discharge of the ammonia-mixed fuel progresses, the state of the liquid phase in the mixing sealed container 16 (i.e., the ammonia-mixed fuel discharged from the liquid-phase discharge line 22) changes so as to move on the liquid phase line AQ from point B (ammonia concentration _xB ) in Fig. 1(a) at the start of discharge to point Q of pure ammonia (ammonia concentration 100 mass%), and accordingly, the state of the gas evaporated to the gas phase side changes so as to move on the gas phase line OQ from point O (ammonia concentration _yO ) in Fig. 1(a) to point Q of pure ammonia. During this process, the internal pressure in the mixing sealed container 16 decreases from the azeotropic vapor pressure at point O to the saturated vapor pressure of pure ammonia at point Q with the discharge of the liquid phase.
When discharging an ammonia-mixed fuel having a liquid phase ammonia concentration between x _B and 100 mass %, the above behavior is equivalent to starting from a point midway along each of the liquid phase line BQ and the gas phase line OQ.
Therefore, in the composition region where the liquid phase becomes a single-phase solution, the above-mentioned composition change accompanying the progress of the discharge of the ammonia mixed fuel must be allowed. However, in the above, if the stirring of the liquid phase is stopped during the above-mentioned discharge and the mass transfer of each component in the liquid phase and at the gas-liquid interface is suppressed, the liquid phase composition change near the liquid phase discharge line 22 in the mixing sealed container 16 where the ammonia mixed fuel is discharged can be reduced. Furthermore, if the opening of the liquid phase discharge valve 22a is widened and the discharge speed of the ammonia mixed fuel is increased, a larger portion of the ammonia mixed fuel in the mixing sealed container 16 can be discharged while suppressing the above-mentioned composition change. If the composition change during the discharge may cause some kind of trouble when using the ammonia mixed fuel as fuel, the liquid phase discharge valve 22a is closed at that point and the discharge is terminated.

(ii) In the case of a liquid phase composition in which the liquid phase separates into two phases In the gas-liquid-liquid equilibrium diagram at 20°C in Fig. 1 (a), the region in which the liquid phase separates into two phases is the region between points A and B of the liquid phase ammonia concentrations _xA to _xB . By introducing liquefied ammonia and liquefied propane into the mixing sealed vessel 16 at a feed composition ratio corresponding to the liquid phase composition (ammonia concentration _xC ) of point C (average state of the entire two liquid phases) at an arbitrary position within this region, and stirring and mixing, a state in which the liquid phase is separated into two phases is formed: a liquid phase mainly composed of propane with an ammonia concentration of _xA , which is the saturated concentration, and a liquid phase mainly composed of ammonia with a propane concentration of 1- _xB , which is the saturated concentration (at this time, the ammonia concentration is _xB ). At this time, since the specific gravity of liquefied propane is smaller than that of liquefied ammonia, the propane-based phase with an ammonia concentration of _xA is in the upper layer, and the ammonia-based phase with an ammonia concentration of _xB is in the lower layer. In general, other constituent hydrocarbons of the liquefied petroleum gas and the liquefied petroleum gas mixtures thereof all have a specific gravity smaller than that of the liquefied ammonia, so the phase mainly composed of these always becomes the upper layer. At this time, as long as the two-phase separation state continues, the lower layer mainly composed of ammonia having a constant ammonia concentration _xB can be discharged from the liquid phase discharge line 22 as an ammonia mixed fuel by discharge based on the saturated vapor pressure in the mixing closed vessel 16.
In the above, in order to discharge as much of the lower layer, which is mainly composed of ammonia and has the above-mentioned constant ammonia concentration _xB , as possible, it is preferable that liquefied ammonia and liquefied propane are introduced into the mixing closed vessel 16 at a charging composition ratio such that the position of the above-mentioned point C (average state of the entire two liquid phases) is located near the center of the line segment AB and closer to point B. This is because, if point C is close to point A, the absolute amount of the lower layer with ammonia concentration _xB that can be discharged decreases due to the above-mentioned principle of leverage, and the time when the discharge of the lower layer ends and the discharge of the upper layer with ammonia concentration _xA begins is accelerated, and if point C is too close to point B, the upper layer disappears early due to the change (increase) in the average concentration of the liquid phase associated with evaporation during the discharge of the liquid phase (when point C is close to point B, relatively more propane is evaporated than ammonia) as described in (i) above, and the state transitions to the single phase state described in (i) above, and the ammonia concentration rises from _xB .

As described above, in the mixing closed vessel 16 of Fig. 2, if the piping of the liquid phase discharge line 22 is extended upward from the bottom surface of the mixing closed vessel 16 and the position of the discharge outlet at the upper end of the piping is configured to be slightly higher than the bottom surface of the upper layer at the start of discharge (22 ₂ in Fig. 3(a)), it is possible to discharge only the upper layer mainly composed of propane having an ammonia concentration of _xA as an ammonia mixed fuel, leaving the lower layer having an ammonia concentration of _xB as described above. In this case, in order to discharge as much of the upper layer as possible, it is preferable that the liquefied ammonia and the liquefied propane are introduced into the mixing closed vessel 16 at a charging composition ratio such that the position of the above-mentioned point C (average state of the entire two liquid phases) is located closer to point A than near the center of the line segment AB.
Furthermore, as described above, if the discharge port in the mixing closed vessel 16 has both the liquid phase discharge line 22 on the bottom surface of the mixing closed vessel 16 as shown in Fig. 2 and the liquid phase discharge line ₂₂₁ whose discharge port is located slightly higher than the bottom of the upper layer at the start of discharge as shown in Fig. 3(a) (Fig. 3(b)), it is possible to simultaneously discharge the lower layer having an ammonia concentration _xB and the upper layer having an ammonia concentration _xA as an ammonia mixed fuel. In this case, it is preferable that the liquefied ammonia and the liquefied propane are introduced into the mixing closed vessel 16 at a charge composition ratio such that the position of the above-mentioned point C (average state of the entire two liquid phases) is near the center of the line segment AB.
However, in the above, as the discharge of the upper layer having the ammonia concentration _xA and/or the lower layer having the ammonia concentration _xB progresses, the gas-liquid interface and/or the interface between the upper layer and the lower layer will descend, and eventually the height position of the discharge port in the upper layer and/or the lower layer in the mixing sealed container 16 of the liquid phase discharge lines 22, 22 ₁ , 22 ₂ will reach the descending gas-liquid interface and/or the interface between the upper layer and the lower layer, and the discharge of the upper layer and/or the lower layer will no longer be able to continue. Therefore, if it is desired to avoid the mixing of a different phase (a layer of a liquid phase other than the target or a gas phase) in the discharge, the liquid phase discharge valves 22 a, 22 a ₁ , 22 a ₂ will be closed by that time.

In the above, when liquefied ammonia and liquefied propane are introduced into the mixing sealed vessel 16 at a charging composition ratio corresponding to the liquid phase composition (ammonia concentration x _C ) in the two-phase separation region, the ammonia concentration x _A in the upper layer (x _A corresponds to the saturation concentration of ammonia in the upper layer) and the ammonia concentration x _B in the lower layer (1-x _B corresponds to the saturation concentration of propane in the lower layer) can be controlled as follows by keeping the temperature of the liquid phase in the mixing sealed vessel 16 at a predetermined temperature while stirring and mixing it with the temperature control mechanism.
For example, the ammonia concentrations _xA ' and _xB ' at both ends of the two-phase separation region at 0°C shown in FIG. 1(a) are about 6.7% by mass and about 93.5% by mass, respectively, as described above. At 20°C, the liquid phase composition range of the two-phase separation region is smaller than that at 0°C, with _xA being about 16.2% by mass and _xB being about 86.5% by mass. As described above, the liquid phase temperature in the mixing sealed vessel 16 is maintained between 0°C and 20°C by the temperature control mechanism, so that the upper layer and/or lower layer having the above compositions ( _xA , _xB ) can be discharged. If the holding temperature of the liquid phase during stirring and mixing is further lowered below 0°C, _xA and _xB approach 0% by mass and 100% by mass, respectively. Moreover, when the liquid phase temperature is further increased beyond 20°C, the two-phase separation region gradually shrinks, _xA and _xB approach each other, and when the critical solution temperature (about 33°C) is reached, the two-phase separation region disappears, and _xA and _xB become equal to the ammonia concentration _xO (= _yO ≈32 mass%) at the azeotropic point O at the critical solution temperature.
Therefore, in an ammonia-propane mixture system, liquefied ammonia and liquefied propane are introduced into the mixing sealed vessel 16 at a charging composition ratio corresponding to an arbitrary liquid phase composition (ammonia concentration x _C ) in the two-phase separation region, and the liquid phase temperature in the mixing sealed vessel 16 is maintained at a predetermined constant value from a low temperature below 0° C. to the critical solution temperature (about 33° C.), whereby the ammonia concentrations in the upper and lower layers can be controlled to a predetermined value x _A within a range from near 0 mass % to the ammonia concentration x _O (=y _O ) at the azeotropic point O at the critical solution temperature (about 33° C.) and a predetermined value x _B within a range from the ammonia concentration x _O (=y _O ) at the azeotropic point O at the critical solution temperature (about 33° C.) to near 100 mass %, respectively. As a result, the upper layer and/or the lower layer having these compositions can be discharged as a single-phase solution of ammonia mixed fuel from the liquid phase discharge lines _22-1 and/or _22-2 , respectively.
In a special situation, when the raw materials ammonia and propane are introduced into the mixing closed vessel 16 at an introduction composition ratio equal to the azeotropic composition _xO (= _yO ≈32 mass%) at the critical azeotropic temperature (about 33°C), stirred and mixed, and the liquid phase temperature is maintained at the critical azeotropic temperature (about 33°C) or higher by the temperature control mechanism, the liquid phase of the mixture in the mixing closed vessel 16 becomes a single-phase solution of the azeotropic composition. The composition of the vapor evaporated from this liquid phase is always the same azeotropic composition as the liquid phase, so that the entire amount of the liquid phase in the mixing closed vessel 16 can be discharged from the liquid phase discharge line 22 (22 ₁ ) as an ammonia mixed fuel in a single-phase solution while maintaining the liquid phase composition at the azeotropic composition, regardless of the progress of evaporation accompanying the discharge of the liquid phase.
According to the manufacturing apparatus 10 of this embodiment, not only for the ammonia-propane system described above, but also for other liquefied petroleum gas component hydrocarbons, whose mixtures with ammonia similarly show azeotropic gas-liquid equilibrium of liquid-phase two-phase separation, and for the case where a liquefied petroleum gas mixture of these is used as a combustion improver, the liquid phase of the mixture in the mixing sealed vessel 16 can be discharged as an ammonia mixed fuel while controlling the discharge composition, in the same manner as in the case of the ammonia-propane system described above, although there are differences in the temperature range, pressure range, and composition range in which the mixture is separated into two phases, by using a similar apparatus and method.
However, as described above, with the discharge of the ammonia mixed fuel, the gas-liquid interface of the mixture in the mixing sealed container 16 and the interface between the upper and lower layers at the time of liquid phase separation may drop and reach the discharge outlet positions of the liquid phase discharge lines 22, 22 ₁ , 22 ₂ in the mixing sealed container, so that different phases may be mixed into the ammonia mixed fuel, and the evaporation of the mixture may progress, which may change the composition of the discharged ammonia mixed fuel. This requires attention.

In the manufacturing apparatus 10 according to one embodiment, in addition to the above-mentioned configurations shown in Fig. 2 and Fig. 3(a) and (b), as shown in Fig. 4, a nitrogen gas introduction line 30b is provided, which is configured to introduce the nitrogen gas into the gas phase portion in the mixing sealed container 16 at a discharge pressure equal to or higher than the saturated vapor pressure of the mixture in the mixing sealed container 16. In Fig. 4, when the same configuration and function as those of the components shown in Fig. 2 are used, the same reference numerals are used and the description thereof is omitted. This makes it possible to quickly discharge the ammonia mixed fuel while suppressing the change in the liquid phase composition due to the progress of evaporation of the mixture in the mixing sealed container 16 accompanying the discharge of the ammonia mixed fuel, as described above. This embodiment can be applied to both the case where the liquid phase of the mixture in the mixing sealed container 16 becomes a single phase and the case where it separates into two phases (separated into upper and lower layers). Fig. 4 shows the former form.
The nitrogen gas introduction line 30b is led from a storage container such as a general pressurized nitrogen gas cylinder filled with an internal pressure of about 14.7 MPa. If the nitrogen gas has an equivalent pressure, it may be branched from the piping of the nitrogen gas introduction mechanism 30 as shown in FIG. 4. The nitrogen gas introduction line 30b is provided with a nitrogen gas pressure reducing valve 30c, a nitrogen gas pressure gauge 30d, and a nitrogen gas adjustment valve 30e from its upstream side to the mixing sealed container 16. The nitrogen gas introduced through the nitrogen gas introduction line 30b is reduced in pressure by the pressure reducing valve 30c so that the indication of the nitrogen gas pressure gauge 30d becomes equal to or higher than the saturated vapor pressure of the mixture in the mixing sealed container 16 (for example, the saturated vapor pressure + about 0.05 to 0.1 MPa). When the liquid phase of the mixture is discharged from the mixing closed vessel 16, the nitrogen gas regulating valve 30e is opened in conjunction with the opening of the liquid phase discharge valves 22a, _22a1 , and _22a2 , and the mixture is forced out by the nitrogen gas introduced from the gas phase side and discharged from the liquid phase discharge line as an ammonia mixed fuel. The operation of these valves is controlled by the control device 32.
When the ammonia mixed fuel is discharged by introducing the nitrogen gas, the nitrogen introduced in the mixed sealed container 16 diffuses and dilutes the evaporated gas from the mixture in the container, which causes a shift in the gas-liquid equilibrium at the gas-liquid interface, and the gas continues to evaporate from the liquid phase during the discharge of the liquid phase. Strictly speaking, however, the change in the liquid phase composition is reduced. In particular, when the ammonia concentration in the mixture is relatively low and the concentration of the combustion improver (liquefied petroleum gas or its component hydrocarbon species) is high, the specific gravity of the evaporated gas of these mixtures is greater than that of nitrogen gas, and the evaporated gas tends to remain near the gas-liquid interface below the gas phase, thereby suppressing the shift in the gas-liquid equilibrium and the change in the composition of the ammonia mixed fuel described above. In addition, the longer the container shape of the mixing sealed container 16 is in the vertical direction and the greater the flow rate of the nitrogen gas introduction, the closer the discharge of the internal fluid becomes to a so-called "plug flow", and the less likely the convection and diffusive dilution of the nitrogen gas and the evaporated gas described above occurs, thereby suppressing the composition change described above.

In addition to the above-mentioned configuration shown in Fig. 2, the manufacturing apparatus 10 of one embodiment is configured with the above-mentioned quantitative introduction mechanism for ammonia and combustion improver so that the raw material ammonia and combustion improver can be continuously introduced into the mixing sealed container 16 through the introduction lines 18 and 20 against the saturated vapor pressure of the mixture in the mixing sealed container 16 at a flow rate equal to the composition ratio and flow rate of the liquid phase discharged through the liquid phase discharge line 22. An example of this embodiment is shown in Fig. 5. In Fig. 5, the same reference numerals are used for components having the same configuration and function as those shown in Fig. 2, and their description is omitted.
These configurations make it possible to maintain constant the height position of the gas-liquid interface of the mixture in the mixing sealed vessel 16, and the height position of the interface between the upper and lower layers when the liquid phase of the mixture separates into two phases, and to continuously discharge the liquid phase with a constant composition as the ammonia mixed fuel. This embodiment can also be applied to both the case where the liquid phase of the mixture in the mixing sealed vessel 16 becomes a single phase and the case where it separates into two phases (separation into upper and lower layers). Figure 5 shows the latter embodiment in which both the upper and lower layers are discharged.
In this embodiment, in addition to the components shown in Fig. 2 as equipment included in the quantitative introduction mechanism, as shown in Fig. 5, liquid feed pumps 18d and 20d are provided in the ammonia introduction line 18 and the combustion improver introduction line 20, respectively, so that the raw material liquefied ammonia and the combustion improver can be introduced against the saturated vapor pressure of the mixture in the mixing sealed container 16. As these liquid feed pumps, the above-mentioned high lift pumps are selected. In addition, discharge flow meters 22b, _22b1 , and _22b2 that measure the flow rate of the liquid phase portion discharged as ammonia mixed fuel from the mixing sealed container 16 through the liquid phase discharge lines 22, ₂₂₁ , and ₂₂₂ , and composition evaluation means 22c, _22c1 , and _22c2 that evaluate the composition (ammonia concentration, etc.) of the liquid phase portion are provided in the liquid phase discharge lines 22, ₂₂₁ , and ₂₂₂ . These may be located either upstream or downstream of the liquid phase discharge valves 22a, 22a ₁ , 22a ₂ .
When discharging the ammonia mixed fuel, the liquid phase discharge valves 22a, _22a1 , _22a2 are opened, and liquid phase discharge is started. At the same time, the control device 32 starts receiving the discharge flow rates passing through the liquid phase discharge lines 22, ₂₂₁ , ₂₂₂ measured by the discharge flow meters 22b, _22b1 , _22b2 , and the liquid phase compositions measured by the composition evaluation means 22c, _22c1 , _22c2 , and calculates the flow rates of ammonia and combustion improver in the discharged liquid phase passing through the liquid phase discharge lines 22, ₂₂₁ , ₂₂₂ , respectively, from these. Furthermore, the output of the liquid delivery pumps 18d and 20d and/or the opening of the regulating valves 18c and 20c are controlled by the control signal sent by the control device 32 so that the calculated discharge flow rate of the ammonia and the combustion improver and the introduction flow rate value of the raw material liquefied ammonia and the combustion improver introduced into the mixing sealed container 16 measured by the flowmeters 18a and 20a are equal to each other. During this process, the mixing and stirring of the liquid phase of the mixture in the mixing sealed container 16 and the temperature control are continued as they are. According to these controls, the height positions of the gas-liquid interface and the interface between the upper and lower layers of the mixture in the mixing sealed container 16 are kept constant, and the composition of the gas-liquid phase and the saturated vapor pressure are also kept constant. Therefore, even if the discharge of the liquid phase proceeds, the original gas-liquid equilibrium state is maintained as it is, and evaporation into the gas phase does not occur, so the liquid phase composition is also kept constant. Therefore, it is possible to produce an ammonia mixed fuel with a constant composition and discharge it continuously.

In the continuous production of ammonia mixed fuel with a constant composition by continuously additionally introducing the above-mentioned raw materials, the composition evaluation means 22c, _22c1 , _22c2 are preferably those capable of rapid in-line measurement and evaluation in the liquid phase discharge line, and examples thereof include ammonia or combustion improver concentration evaluation means based on evaluation of absorption intensity in the infrared absorption band of each component such as N-H stretching vibration (in the case of quantitative determination of ammonia) or C-H stretching vibration (in the case of quantitative determination of hydrocarbons) by a Fourier transform infrared absorption spectrometer based on a predetermined calibration method (calibration curve), refractive index of the discharged liquid phase measured by a refractometer, and sound speed measurement by ultrasonic irradiation using an ultrasonic concentration meter, but are not limited to these. The data measured by such composition evaluation means is converted into the concentration of ammonia or combustion improver by a calibration method built into the composition evaluation means itself, or is transmitted to the control device 32 as the measured data itself, and the latter is converted into the concentration of ammonia or combustion improver in the control device 32, and then multiplied by the flow rate value of the liquid phase discharge lines ₂₂ , ₂₂₁ , ₂₂₂ transmitted from the discharge flow meters 22b, _22b1 , 22b2 to calculate the discharge flow rates of ammonia and combustion improver. Note that when the relationship between the initial amounts of liquefied ammonia and combustion improver introduced into the mixing closed vessel 16 before the discharge of the liquid phase and the liquid phase composition is known, the liquid phase composition can be obtained from the initial amounts introduced, so the composition evaluation means 22c, _22c1 , _22c2 can be omitted.

As shown in FIG. 2, 3(a), 3(b), 4, and 5, the manufacturing apparatus 10 of one embodiment includes a surfactant storage container 26 for storing a surfactant, a surfactant introduction line 28, and a liquid feed pump 28d. The surfactant introduction line 28 connects the surfactant storage container 26 and the mixing sealed container 16. Since the surfactant introduction line 28 does not spontaneously introduce the surfactant into the mixing sealed container 16 due to its low saturated vapor pressure, the surfactant is supplied from the surfactant storage container 26 to the mixing sealed container 16 using the liquid feed pump 28d. The surfactant introduction line 28 is provided with a flow meter 28a and regulating valves 28b and 28c configured to introduce a predetermined amount of the surfactant into the mixing sealed container 16 as a constant amount introduction mechanism of the surfactant. The control device 32 receives the measurement result by the flow meter 28a, generates a control signal for controlling the opening degree of the regulating valves 28b and 28c, and sends the generated control signal to the regulating valves 28b and 28c. However, as described later, when the state of the surfactant is a viscous slurry or mud, the flowmeter 28a and the regulating valves 28b, 28c must be adapted to the state and have a hard-to-clog specification. Furthermore, as described later, a liquid feed pump 28d adapted to the transfer of a viscous slurry or mud-like surfactant must be adopted. When it is difficult to control the amount of the surfactant by opening and closing the regulating valves 28b, 28c, the discharge amount of the liquid feed pump 28d itself is controlled by a control signal generated by the control device 32, so that the surfactant is supplied at a fixed amount. That is, the liquid feed pump 28d is also included in the mechanism for introducing a fixed amount of the surfactant. Furthermore, the nitrogen gas introduction mechanism 30 replaces the gas present in the surfactant introduction line 28 as necessary from the viewpoint of explosion prevention when the manufacturing apparatus 10 is started up and after the end of the production of ammonia mixed fuel. For this purpose, a nitrogen gas introduction valve 30a is provided for introducing a predetermined amount of nitrogen gas into the surfactant introduction line 28. The opening degree of the nitrogen gas introduction valve 30a is controlled by the control device 32.
Therefore, in the mixing sealed container 16, the surfactant is stirred and mixed by the stirrer 24 together with the liquid ammonia and the combustion improver, and the mixture containing the surfactant is discharged from the liquid phase discharge line 22. In this way, by using the surfactant, it is possible to easily produce an ammonia-mixed fuel in which the polar ammonia and the non-polar combustion improver are in an emulsion state.

When the combustion improver is the above-mentioned liquefied petroleum gas or its component hydrocarbon species, at least a portion of it is compatible with ammonia at about room temperature (25°C) in the liquid phase in the gas-liquid equilibrium state, but the portion that is not compatible and undergoes phase separation can also be emulsified by adding a surfactant.
As described above, the surfactant used for emulsifying the ammonia-mixed fuel is preferably a mixed surfactant containing at least one nonionic surfactant (A) that has a high ability to form micelles by two-dimensional arrangement at the interface between two liquid phases that are phase-separated in the ammonia-mixed fuel, and at least one ionic surfactant (B) that has a high ability to ionize at the interface, electrostatically repel the micelles, and prevent contact and fusion. As these nonionic surfactants (A) and ionic surfactants (B), those with the molecular structures described above can be suitably used. When using these mixed surfactants, it is preferable to thoroughly mix and disperse them before storing them in a surfactant storage container.
The above-mentioned surfactants are generally in a liquid or solid state at around room temperature (25°C). Ionic surfactants and surfactants having a long-chain alkyl group with a large number of carbon atoms (long chain length) even if they are nonionic often become solid at around room temperature (25°C). When using a mixed surfactant that becomes a liquid state or a stable slurry state in which the solid content does not easily settle after mixing the above-mentioned nonionic surfactant (A) and ionic surfactant (B) and has sufficient fluidity when introduced, it can be introduced into the mixing closed vessel 16 by the surfactant introduction system (surfactant storage vessel 26, surfactant introduction line 28, and liquid delivery pump 28d) shown in Figure 2. On the other hand, when the above-mentioned mixed surfactant becomes a solid or a state with insufficient fluidity close to that of a solid and is difficult to introduce as it is, it is preferable to add a small amount of any of liquefied ammonia, liquefied petroleum gas, and their component hydrocarbon species, which are the raw materials of the mixed fuel, to the surfactant in advance, mix and disperse it, and make it into a fluid state (e.g., slurry or mud) that can be introduced by the above-mentioned surfactant introduction system. When introducing the surfactant into the mixing sealed container 16, if the mixed surfactant is a viscous liquid, slurry, or mud, the liquid delivery pump 28d used is of a type that can quantitatively discharge and deliver such substances.
The surfactant itself has a low saturated vapor pressure at room temperature (25°C) and near atmospheric pressure, which is almost zero. When the surfactant itself is introduced into the mixing sealed container 16 in a liquid state or in a stable slurry state in which solids are unlikely to settle, it is necessary to avoid a situation in which the surfactant cannot be further introduced due to an increase in the internal pressure of the mixing sealed container 16 caused by the advance introduction of a liquefied gas such as ammonia. For this reason, the surfactant is preferably introduced into the mixing sealed container 16 prior to the liquefied gases ammonia, liquefied petroleum gas, and the combustion improver which is a component hydrocarbon of the ammonia and the liquefied petroleum gas. At this time, the surfactant is introduced in a fixed amount by opening and closing the regulating valves 28b and 28c and driving and stopping the liquid sending pump 28d, which are controlled by a control signal generated by the control device 32 based on the time integral value of the flow rate value measured by the flowmeter 28a. On the other hand, as described above, when the surfactant is in a solid or nearly solid state and is introduced into the mixing sealed vessel 16 in a slurried or muddy state by the addition of liquefied ammonia, liquefied petroleum gas, or any of their component hydrocarbon species, it is preferable that a fixed amount is introduced in conjunction with the introduction of the same raw material system of liquefied ammonia, raw liquefied petroleum gas, or any of their component hydrocarbon species.

When the combustion improver is liquefied petroleum gas or a component hydrocarbon of liquefied petroleum gas, the manufacturing apparatus 10 shown in Fig. 2, Fig. 3(a), (b), Fig. 4, and Fig. 5 can be basically used suitably depending on the composition, mixing temperature, and other conditions when manufacturing an ammonia-mixed fuel that has been emulsionized by introducing a surfactant. For example, in the above-mentioned ammonia-propane mixture, the composition range and temperature range in which the mixture separates into upper and lower layers are changed by the effect of emulsification by adding and mixing a surfactant, compared to when no surfactant is added. However, even when the mixture is emulsified by adding a surfactant, the fact that there is a composition range and temperature range in which the mixture separates into upper and lower layers, and that the mixture becomes a single layer due to temperature rise, is essentially the same as when no surfactant is added.
Therefore, for example, by using the manufacturing apparatus 10 shown in FIG. 2 (the apparatus in which the outlet of the liquid phase discharge line 22 is located at the bottom surface of the mixing closed vessel 16), if the composition and temperature conditions are such that the liquid phase of the mixture becomes a single layer, the single layer, or if the mixture is separated into upper and lower two layers, the lower layer, can be discharged as an emulsified ammonia mixed fuel by performing the same operation as in the case of not adding the surfactant described above. Also, for example, by using the manufacturing apparatus 10 shown in FIG. 3(b) (the apparatus in which the outlets of the liquid phase discharge lines 22 ₁ and 22 ₂ are located slightly above the bottom surface of the upper layer of the upper and lower layers of the mixture in the mixing closed vessel 16 and at the bottom surface of the vessel, respectively), the upper layer and/or the lower layer of the liquid phase separated into upper and lower two layers can be discharged as an emulsified ammonia mixed fuel. Also, by using the manufacturing apparatus 10 shown in FIG. 4 having the nitrogen gas introduction line 30b, the composition change accompanying the progress of liquid phase discharge can be suppressed and the liquid phase can be rapidly discharged as an emulsified ammonia mixed fuel.

Furthermore, according to the configuration shown in Fig. 5 in which the raw material ammonia, combustion improver, and surfactant are continuously introduced into the mixing closed vessel 16 at an introduction flow rate equal to the discharge flow rate, it is possible to continuously produce and discharge an emulsified ammonia mixed fuel while suppressing the composition change accompanying the progress of liquid phase discharge of the upper and/or lower layers of the liquid phase separated into two layers. Here, _the manufacturing apparatus 10 in Fig. 5 is provided with a surfactant quantitative introduction mechanism (including liquid feed pump 28d) configured to introduce the surfactant into the mixing closed vessel 16 at an introduction flow rate equal to the discharge flow rate, in addition to the _{above -} mentioned ammonia and combustion improver quantitative introduction mechanism (including liquid feed pump 18d, 20d, discharge flow meters 22a, 22a ₁ , 22a 2, liquid phase composition evaluation means 22b, 22b 1, 22b 2, and control device 32) configured for the above purpose. Here, since the liquid delivery pump 28d needs to be introduced against the saturated vapor pressure of the mixture in the mixing sealed container 16, a pump of the same type as the high lift liquid delivery pump for the liquefied ammonia and the combustion improver described above, which is required to perform the same function, is selected.
In this embodiment, the control device 32 calculates the concentration of the surfactant in the ammonia mixed fuel from the respective amounts of ammonia, the combustion improver, and the surfactant previously introduced into the mixing closed vessel 16 as raw materials. Furthermore, the control device 32 receives the measured values of the discharge flow rates of the ammonia mixed fuel measured by the discharge flow meters 22a, _22a1 , and _22a2 from the start of the discharge of the ammonia mixed fuel, and obtains the discharge flow rates of the surfactant discharged through the liquid phase discharge lines 22, ₂₂₁ , and ₂₂₂ by multiplying the discharge flow rates by the concentration of the surfactant. The control device 32 transmits control signals for adjusting the output of the liquid feed pump 28d and the openings of the regulating valves 28b and 28c so that a constant amount of the surfactant is continuously introduced from the surfactant storage vessel 26 into the mixing closed vessel 16 at a flow rate equal to the discharge flow rate.

2, 4, and 5 may be partially modified as described below to produce an ammonia-mixed fuel by using at least one of naphtha, gasoline, kerosene, and diesel as (a) and at least one of naphtha, gasoline, kerosene, and diesel as (b), instead of using liquefied petroleum gas as (a) and at least one of hydrocarbon species contained as a component in liquefied petroleum gas as (b). In this case, the sealed container 14 for storing the combustion improver is a container for storing at least one of naphtha, gasoline, kerosene, and diesel, or at least one of hydrocarbon species contained as a component in these. These feedstock hydrocarbons, which are liquid at around room temperature (25° C.) and around atmospheric pressure, are easier to ignite because they have a lower ignition temperature than ammonia, and have a higher burning speed than ammonia (about 5 to 7 times that of ammonia in laminar burning speed), making them easier to burn. For this reason, naphtha, gasoline, kerosene, and diesel, as well as the hydrocarbon species contained as components thereof, can also be used as a combustion improver for ammonia.
When using naphtha, gasoline, kerosene, and diesel, which are liquid at room temperature (25°C) and atmospheric pressure, and the combustion improver which is a component hydrocarbon of these, the saturated vapor pressure of the combustion improver in the combustion improver storage sealed container 14 is almost zero at room temperature (25°C), so the liquid phase is not discharged by the saturated vapor pressure and does not spontaneously flow into the mixing sealed container 16. Therefore, the combustion improver introduction line 20 needs to be further provided with a liquid feed pump 20d for supplying the combustion improver from the combustion improver storage sealed container 14 to the mixing sealed container 16. At this time, the combustion improver quantitative introduction mechanism also includes the liquid feed pump 20d, and its drive and output are controlled by a control signal generated by the control device 32. When this liquid feed pump is provided, during the quantitative supply of the combustion improver, the liquid feed pump is output-controlled or driven or stopped by a control signal generated by the control device 32 in conjunction with the opening or opening/closing of the regulating valves 20b and 20c.
When naphtha, gasoline, kerosene, light oil, and the combustion improver and surfactant, which are component hydrocarbons of these, are introduced into the mixing sealed container 16 by liquid transfer using the liquid transfer pump 20d, it is necessary to avoid a situation in which the internal pressure of the mixing sealed container 16 increases due to the prior introduction of ammonia, which is a liquefied gas, during the introduction of these, making it impossible to introduce them any further. For this reason, when a liquid transfer pump with a particularly high lift is not used, naphtha, gasoline, kerosene, light oil, and the combustion improver and surfactant, which are component hydrocarbons of these, are preferably introduced into the mixing sealed container 16 before ammonia. During the introduction, in many cases, no particular temperature control is required. However, during the subsequent introduction of ammonia, as described above, the saturated vapor pressure of the mixture in the mixing sealed container 16 must always be lower than the internal pressure of the ammonia storage sealed container 12 (the saturated vapor pressure of ammonia), so the temperature of the liquid phase of the mixture in the mixing sealed container 16 must be maintained at a predetermined temperature at which the saturated vapor pressure is sufficiently low. As described above, when the surfactant is in a solid or nearly solid state, it is preferable to introduce the surfactant into the mixing sealed vessel 16 in a slurried or muddy state by adding liquefied ammonia, naphtha, gasoline, kerosene, light oil, or any of these component hydrocarbon species, and in this case, it is preferable to introduce a fixed amount of the surfactant in conjunction with the introduction of the same raw material system of liquefied ammonia, naphtha, gasoline, kerosene, light oil, or any of these component hydrocarbon species, or any of these component hydrocarbon species.

When the combustion improver is naphtha, gasoline, kerosene, diesel, or at least one of these component hydrocarbons, as in the case of the liquefied petroleum gas and its component hydrocarbons described above, in the absence of surfactants, in the equilibrium state, it can either separate into two phases, a polar liquefied ammonia phase and a combustion improver phase, or become a homogeneous solution. In this case, as in the case of liquefied petroleum gas and its component hydrocarbons, the two-phase separation state changes to a homogeneous solution state by heating. Furthermore, the critical solution temperature described above also exists, and above this temperature, any composition becomes completely miscible. However, when the combustion improver is naphtha, gasoline, kerosene, diesel, or their component hydrocarbons, the mixed fuel with liquefied ammonia generally does not exhibit azeotropic behavior, and its saturated vapor pressure is approximately equal to or lower than the saturated vapor pressure of pure ammonia at the same temperature. When it separates into two layers, the specific gravity of naphtha, gasoline, kerosene, diesel, and their component hydrocarbons are all greater than the specific gravity of liquefied ammonia, so in a sealed container, the phase mainly composed of these combustion improvers becomes the lower layer of the phase mainly composed of liquefied ammonia, unlike the case of liquefied petroleum gas and its component hydrocarbons.

Even when the combustion improver is naphtha, gasoline, kerosene, light oil, or a component hydrocarbon thereof, if it is desired to dissolve the combustion improver and/or ammonia in the other liquid phase to a degree greater than the solubility determined by the above-mentioned gas-liquid-liquid equilibrium, emulsification by adding a suitable surfactant is required. In particular, when the combustion improver is kerosene, light oil, or a component hydrocarbon thereof, in the low temperature range from about room temperature (25°C) to about 50°C, where the vapor pressure can be kept low, the solubility of both the combustion improver and/or ammonia remains at a low concentration of about 5 mass% or less, so the addition of a surfactant becomes important. In this case, the solubility of the liquefied ammonia and the combustion improver that can be mixed and dispersed is almost governed by the performance of the surfactant and the amount of the surfactant added. For this reason, it is preferable to add a sufficient amount of a suitable surfactant so that the entire mixture becomes a uniformly emulsified layer. When the amount of surfactant added is small, it is preferable that the transiently emulsified portion is quickly used up by combustion before it separates into two layers, upper and lower. Alternatively, after being stored for a certain period of time in a storage sealed container described later, the mixture may be re-stirred to return to an emulsion state in which the entire mixture is well dispersed, and then the mixture may be burned. When naphtha, gasoline, or their component hydrocarbons (especially aromatic hydrocarbons), which are relatively compatible with ammonia even without the addition of a surfactant, are used as a combustion improver, the addition of a surfactant may not be necessary. In that case, the surfactant introduction system (surfactant storage container 26, surfactant introduction line 28, flow meter 28a, control valves 28b, 28c, and liquid delivery pump 28d) can be omitted.
Even when the combustion improver is naphtha, gasoline, kerosene, diesel, or any of their component hydrocarbons, it is possible to discharge the upper and/or lower layers of the two-phase separated liquid phase as an ammonia mixed fuel by using the liquid phase discharge line 22 ₂ for discharging the upper layer of the two-phase separated liquid phase and the associated devices (liquid phase discharge valve 22 a ₂ , discharge flow meter 22 b ₂ , and composition evaluation means 22 c ₂ ) shown in FIG. 3( a ) and ( b ) or FIG. 5 .

In order to produce a homogeneous and stable ammonia mixed fuel in which the combustion improver contains naphtha, gasoline, kerosene, diesel, or at least one of these component hydrocarbons, a mixed surfactant having a molecular structure common to that of the above-mentioned combustion improver containing liquefied petroleum gas and its component hydrocarbons can be used. However, as described above, the chain length of the long-chain alkyl group or alkenyl group of the surfactant is often preferably longer than that of liquefied petroleum gas and its component hydrocarbons. When a sufficient amount of such a suitable mixed surfactant is added and mixed by stirring, the phase separation portion (ammonia or combustion improver) is dispersed in the other phase by emulsification, and the entire mixed fuel can be homogenized. At that time, it is preferable to maintain the temperature range in which the emulsification performance of the surfactant is fully exhibited, as in the above-mentioned case in which the combustion improver is liquefied petroleum gas and its component hydrocarbons. If the ammonia mixed fuel produced in the above manner is taken out and burned in that state, it shows high combustibility.
In addition, even when the combustion improver is naphtha, gasoline, kerosene, diesel, or its component hydrocarbons, when the production apparatus of FIG. 2 is used, when the liquid phase portion of the emulsified mixture is discharged from the liquid phase discharge line 22, the composition of the discharged liquid phase changes in the same manner as when the combustion improver is liquefied petroleum gas or its component hydrocarbons. That is, with the discharge of the liquid phase, the gas-liquid interface of the mixture in the mixing closed vessel 16 descends, and evaporation (boiling) of the mixture from the liquid phase to the gas phase occurs. At that time, regardless of the liquid phase composition, the ammonia concentration in the evaporated gas is higher than the ammonia concentration in the liquid phase, so that the ammonia concentration in the liquid phase decreases with the progress of the liquid phase discharge.
In contrast, by using the manufacturing apparatus 10 in Fig. 4 (equipment equipped with a combustion improver liquid feed pump 20d, not shown), similarly to the above-mentioned case where the combustion improver is liquefied petroleum gas or its component hydrocarbon species, it is possible to suppress the above-mentioned composition change in the discharged liquid phase by pressurizing and introducing nitrogen into the gas phase in the sealed mixing vessel 16, and quickly discharge the ammonia mixed fuel. Also, by using the manufacturing apparatus 10 in Fig. 5 (liquid phase discharge line ₂₂₂ and the above-mentioned equipment attached thereto are often omitted), it is possible to continuously discharge the ammonia mixed fuel without causing the above-mentioned composition change in the discharged liquid phase by continuously introducing a fixed amount of the raw material liquefied ammonia, combustion improver, and surfactant at a flow rate equal to the respective discharge flow rates of the ammonia, combustion improver, and surfactant in the discharged liquid phase (the pumps for sending these liquids are selected to have the above-mentioned high head).
As described above, even when the combustion improver is naphtha, gasoline, kerosene, diesel, or any of their component hydrocarbons, the manufacturing apparatus 10 shown in Fig. 2, Fig. 4 (which are equipped with a combustion improver liquid delivery pump 20d, not shown), and Fig. 5 can be used to manufacture an ammonia-mixed fuel with the respective benefits. In this case, a series of controls including the above-mentioned controls, such as the introduction of a fixed amount of liquefied ammonia, combustion improver, and surfactant, and temperature control during stirring and mixing, are performed based on the control signal of the control device 32, basically in the same manner as when the combustion improver is liquefied petroleum gas or any of its component hydrocarbons, as described above.

FIG. 6 is a diagram showing an example of the configuration of the manufacturing apparatus 10 of another embodiment different from the configuration of the manufacturing apparatus 10 shown in FIG. 2. The example shown in FIG. 6 shows the form of the apparatus when using the raw material alcohol having 3 or less carbon atoms in the molecule as the above (c) such as methanol as a combustion improver. The raw material alcohol has a lower ignition temperature than ammonia, so it is easy to ignite, and also has a higher combustion speed (about 6 to 7 times that of ammonia in laminar combustion speed), so it is easy to burn. In addition, compared to liquid fossil fuels that have been widely used in the past, such as heavy oil, light oil, kerosene, and gasoline, less CO ₂ is generated per calorific value during combustion. For this reason, the raw material alcohol is preferable as a combustion improver for ammonia. In addition, the raw material alcohol has polarity and further generates hydrogen bonds between the molecules with ammonia, so that in a gas-liquid equilibrium state, the liquid phase portion of the mixed fuel with the ammonia becomes a compatible solution state over a wide composition range and temperature range. At that time, the mixed fuel does not show azeotropic behavior, and its saturated vapor pressure is lower than the saturated vapor pressure of pure ammonia at the same temperature. For this reason, a surfactant is often not necessary, and the surfactant introduction system (surfactant storage container 26, surfactant introduction line 28, flowmeter 28a, regulating valves 28b, 28c, and liquid delivery pump 28d) can be omitted in the manufacturing apparatus 10. Also, if the external environmental temperature is room temperature (25°C) or in the vicinity thereof, for example, about 0°C to 40°C, in many cases, there is no need to adjust the temperature during stirring and mixing. Therefore, when the combustion improver is raw material alcohol, the configuration of the manufacturing apparatus 10 can be simplified. Note that the symbols of the components shown in FIG. 6 are also given the same symbols when they have the same configuration and function as the components shown in FIG. 2, and their explanations are omitted.
The combustion improver storage sealed container 14 shown in Fig. 6 stores raw material alcohol. The raw material alcohol has a low saturated vapor pressure and is not discharged at the saturated vapor pressure in the combustion improver storage sealed container 14, and is not spontaneously introduced into the mixing sealed container 16, so a liquid feed pump 20d is provided. The liquid feed pump 20d supplies the raw material alcohol from the combustion improver storage sealed container 14 to the mixing sealed container 16. In addition, when the raw material alcohol, which is liquid at around room temperature (25°C) and around atmospheric pressure, is introduced, there is no need to adjust the temperature. However, when the liquefied ammonia is introduced after that, if the liquid feed pump 20d is not a particularly high lift pump, it is necessary to maintain the temperature in the mixing sealed container 16 so that the gas phase internal pressure in the mixing sealed container 16 is always lower than the saturated vapor pressure in the storage sealed container of the liquefied ammonia, which is the raw material to be introduced.

2 is used, the composition of the discharged liquid phase changes as in the case where the combustion improver is liquefied petroleum gas or its component hydrocarbons when the liquid phase portion of the mixture in a solution state is discharged from the liquid phase discharge line 22. That is, as the liquid phase is discharged, the gas-liquid interface of the mixture in the mixing closed vessel 16 descends, and evaporation (boiling) of the mixture from the liquid phase to the gas phase occurs. At that time, regardless of the liquid phase composition, the ammonia concentration in the evaporated gas is higher than the ammonia concentration in the liquid phase, and therefore the ammonia concentration in the liquid phase decreases as the liquid phase discharge progresses.
In contrast, by using the manufacturing apparatus 10 in Fig. 4 (equipped with a combustion improver liquid feed pump 20d, not shown), similarly to the above-mentioned case where the combustion improver is liquefied petroleum gas or its component hydrocarbon species, it is possible to suppress the above-mentioned composition change in the discharged liquid phase by pressurizing and introducing nitrogen into the gas phase in the sealed mixing vessel 16, and quickly discharge the ammonia mixed fuel. Also, by using the manufacturing apparatus 10 in Fig. 5 (omitting the liquid phase discharge line ₂₂₂ and the above-mentioned equipment attached thereto), it is possible to continuously discharge the liquefied ammonia and combustion improver as raw materials as ammonia mixed fuel without causing the above-mentioned composition change in the discharged liquid phase by continuously introducing a fixed amount (the pumps for sending these liquids are selected to have the above-mentioned high head) at a flow rate equal to the respective discharge flow rates of the ammonia and combustion improver in the discharged liquid phase.
As described above, even when the combustion improver is raw material alcohol, by using the production apparatus 10 of Fig. 2 or Fig. 4 (which includes a combustion improver liquid delivery pump 20d, not shown, and omits the surfactant introduction system), or Fig. 5 (which omits the liquid phase discharge line ₂₂₂ and the above-mentioned devices attached thereto, and the surfactant introduction system), it is possible to produce an ammonia-mixed fuel with the respective benefits. In this case, a series of controls including the above-mentioned ones, such as the introduction of a fixed amount of liquefied ammonia and combustion improver and the temperature control during stirring and mixing, are performed based on the control signal of the control device 32, basically in the same manner as in the case where the combustion improver is either liquefied petroleum gas or its component hydrocarbons, as described above.

The combustion improver in the ammonia mixed fuel of one embodiment may be any one of the above (a) to (c), or may be a combination of a plurality of the above (a) to (c). For example, at least one of the above (a) liquefied petroleum gas and the above (b) hydrocarbon species that are components of the liquefied petroleum gas, and the raw material alcohol of (c) may be used together as a combustion improver. FIG. 7 is a diagram showing an example of the configuration of a production apparatus of this another embodiment, and the example shown in FIG. 7 shows an apparatus form in which liquefied petroleum gas or hydrocarbon species that are components of the liquefied petroleum gas and the raw material alcohol are both used as a combustion improver. The symbols of the components shown in FIG. 7 are also given the same symbols when they have the same configuration and action as the components shown in FIG. 2, and their explanations are omitted.
The manufacturing apparatus 10 includes combustion improver storage sealed containers _14-1 , _14-2 . The combustion improver storage sealed container _14-1 stores liquefied petroleum gas or component hydrocarbons of liquefied petroleum gas, and the combustion improver storage sealed container _14-2 stores raw material alcohol. Combustion improver introduction lines 20-1, 20-2 are provided extending from the combustion improver storage sealed containers _14-1 , _14-2 to the mixing sealed container 16, and the combustion improver introduction lines _20-1 , _20-2 are provided with flow meters 20- _a-1 , 20-a- ₂ and control valves 20-b _{- 1} , 20-c- ₁ , 20-b _{-2 ,} 20-c _-2 . The control device 32 receives the measurement results from the flowmeters _20a1 and _20a2 , generates a control signal for controlling the opening degree of the regulating valves _20b1 , _20c1 , _20b2 , and _20c2 , and sends the generated control signal to the regulating valves _20b1 , _20c1 , _20b2 , and _20c2 . The nitrogen gas introduction mechanism 30 is provided to replace the gas present in each introduction line and the mixing sealed container 16 as necessary from the viewpoint of explosion prevention when starting up the production apparatus 10 and after the end of the production of ammonia mixed fuel, and is provided with a nitrogen gas introduction valve 30a for introducing a predetermined amount of nitrogen gas into the combustion improver introduction lines ₂₀₁ and _202. The opening degree of the nitrogen gas introduction valve 30a is controlled by the control device 32.

The raw material alcohol has a low saturated vapor pressure, close to zero at room temperature (25°C). Therefore, it is not discharged at the saturated vapor pressure in the combustion improver storage sealed container ₁₄₂ , and is not spontaneously introduced into the mixing sealed container 16. Therefore, the combustion improver introduction line ₂₀₂ is provided with a liquid feed pump _20d2 for supplying the combustion improver from the combustion improver storage sealed container ₁₄₂ to the mixing sealed container 16. When the raw material alcohol, which is liquid at around room temperature (25°C) and atmospheric pressure, is introduced, there is no need to adjust the temperature. However, when liquefied ammonia, liquefied petroleum gas, and their component hydrocarbons are introduced thereafter, if a particularly high-head liquid feed pump is not used for these, it is necessary to maintain the temperature in the mixing sealed container 16 so that the gas phase internal pressure in the mixing sealed container 16 is always lower than the lowest saturated vapor pressure in each of the storage sealed containers of the raw material liquefied ammonia, liquefied petroleum gas, and their component hydrocarbons. In many cases, it is actually cooled to a temperature lower than the external environment. The quantitative introduction of ammonia, liquefied petroleum gas, the component hydrocarbon species of the liquefied petroleum gas, and the raw material alcohol into the mixing sealed container 16 and the temperature adjustment during the quantitative introduction are performed by the quantitative introduction mechanism and temperature adjustment mechanism described above based on control signals generated by the control device 32.
As another embodiment using a combination of a plurality of the above (a) to (c) as a combustion improver, the configuration shown in Fig. 5 may be partially modified to use naphtha, gasoline, kerosene, and diesel as (a) or at least one of these component hydrocarbons as (b) as a combustion improver together with the raw material alcohol, instead of the above liquefied petroleum gas or the component hydrocarbons of the liquefied petroleum gas, to produce an ammonia-mixed fuel. In this case, for example, naphtha, gasoline, kerosene, diesel, and these component hydrocarbons are stored in a combustion improver storage sealed container _14-1 and introduced into the mixing sealed container 16 through a combustion improver introduction line _20-1 . The saturated vapor pressure of naphtha, gasoline, kerosene, diesel, and these component hydrocarbons is low and is almost zero at room temperature (25°C) like the raw material alcohol, so they are not spontaneously introduced into the mixing sealed container 16, and therefore a liquid feed pump 20d- ₁ is also provided on the combustion improver introduction line _20-1 . There is no particular need to adjust the temperature when naphtha, gasoline, kerosene, diesel, and their component hydrocarbons, which are liquid at about room temperature (25° C.) and atmospheric pressure, and the raw material alcohol are introduced, but when liquefied ammonia is introduced thereafter, the temperature inside the mixing sealed vessel 16 must be maintained so that the gas phase internal pressure inside the mixing sealed vessel 16 is always lower than the saturated vapor pressure inside the storage sealed vessel for the raw material liquefied ammonia. In this case as well, the introduction of a fixed amount and temperature adjustment are performed based on a control signal from the control device 32.

When the above-mentioned non-polar liquefied petroleum gas, naphtha, gasoline, kerosene, light oil, and their component hydrocarbons (hereinafter collectively referred to as "feedstock hydrocarbons"), which are hardly compatible with liquefied ammonia, are used as a combustion improver in combination with liquefied ammonia and feedstock alcohol, the effect of the feedstock alcohol having affinity for both the polar liquefied ammonia and the non-polar feedstock hydrocarbons significantly increases the compatible portion without adding a surfactant. However, depending on the mixing ratio, a surfactant may be required to homogenize by emulsification. For example, when the feedstock alcohol is methanol, when the amount of methanol added is about 10 mass% or less of the total and the liquefied ammonia is about 10 to 70 mass% (the remainder is the feedstock hydrocarbon), the non-polar feedstock hydrocarbons may not be completely dissolved, and the phase mainly composed of them may separate in the liquid phase. A surfactant is required to emulsify and uniformly disperse this phase-separated portion.
The above-mentioned mixed surfactant can be suitably used as the surfactant in this case. When the mixed surfactant is added and stirred, the ammonia mixed fuel is at least partially in an emulsion state. Also, depending on the mixed composition of the ammonia and the combustion improver, it is possible to make the whole of the ammonia mixed fuel in an emulsion state by adding a sufficient amount of surfactant and stirring. In this case, since the solubility and dispersibility of the feedstock hydrocarbons are generally improved by heating, it is preferable to stir while controlling the temperature of the mixture in the mixing closed vessel 16 by the above-mentioned temperature control mechanism based on the control signal of the control device 32 so that the temperature of the mixture is equal to or higher than a predetermined temperature suitable for mixing and dispersion, as necessary. Furthermore, it is preferable to select the mixed surfactant having an alkyl group or alkenyl group with a chain length suitable for fully exerting emulsifying power (emulsification ability) in that temperature range. In addition, when the above-mentioned mixed surfactant is in a solid or nearly solid state and difficult to introduce as it is, it is preferable to add a small amount of any of liquefied ammonia, feedstock hydrocarbons, or feedstock alcohol, which are the raw materials of the ammonia mixed fuel, to the surfactant in advance, mix and disperse it, and make it into a state that can be introduced by the surfactant introduction system (for example, a slurry or mud state). On the other hand, when the total amount of liquefied ammonia and feedstock alcohol is sufficiently large and the ratio of the amount of non-polar feedstock hydrocarbons is small, it may be possible to make it into a solution state in which it is dissolved almost uniformly without adding a surfactant. In such a case, the surfactant introduction system (surfactant storage container 26, surfactant introduction line 28, and liquid delivery pump 28d) can be omitted in the manufacturing apparatus 10.

In addition, as yet another embodiment in which a combination of a plurality of the above (a) to (c) is used as a combustion improver, liquefied petroleum gas, at least one of the component hydrocarbons of liquefied petroleum gas, and naphtha, gasoline, kerosene, diesel, and at least one of the component hydrocarbons of these are used in combination as a combustion improver, and an ammonia-mixed fuel can be produced by a production apparatus similar to that shown in FIG.
In this case, in FIG. 7, liquefied petroleum gas and its component hydrocarbons, which do not require a liquid feed pump when being introduced into the mixing sealed vessel 16, are stored in a combustion improver storage sealed vessel _14-1 , and naphtha, gasoline, kerosene, diesel, and their component hydrocarbons, which require a liquid feed pump ( _20d2 in FIG. 5), are stored in a combustion improver storage sealed vessel _14-2 and are introduced into the mixing sealed vessel 16 through introduction lines _20-1 and _20-2 , respectively.
Among these combustion improvers, i.e., liquefied petroleum gas, naphtha, gasoline, kerosene, light oil, and their component hydrocarbons, the component hydrocarbons of liquefied petroleum gas are partially compatible with liquefied ammonia in the liquid phase in a gas-liquid equilibrium state around room temperature (25°C), but the component hydrocarbons of naphtha, gasoline, kerosene, and light oil, which are liquid around room temperature (25°C) and atmospheric pressure, are almost incompatible. Therefore, in order to produce ammonia-mixed fuel that is uniformly and stably dispersed, emulsification by adding a surfactant is necessary.
The above-mentioned mixed surfactant can be suitably used as the surfactant in this case. When the mixed surfactant is added and mixed and dispersed, the ammonia mixed fuel is at least partially in an emulsion state. Also, although it depends on the mixed composition of the ammonia and the combustion improver, it is possible to make the whole of the ammonia mixed fuel in an emulsion state by adding a sufficient amount of surfactant. In this case, since the solubility of the feedstock hydrocarbon is generally improved by heating, it is preferable to stir the mixture in the mixing closed vessel 16 while adjusting the temperature by the above-mentioned temperature adjustment mechanism based on the control signal of the control device 32 so that the temperature of the mixture in the mixing closed vessel 16 is equal to or higher than a predetermined temperature suitable for mixing and dispersion. Furthermore, it is preferable to select the mixed surfactant having an alkyl group or alkenyl group with a chain length suitable for fully exerting emulsifying power in that temperature range. Note that, if the above-mentioned mixed surfactant becomes solid or close to it and is difficult to introduce as it is, it is preferable to add a small amount of liquefied ammonia or feedstock hydrocarbon, which is the raw material of the ammonia mixed fuel, to the surfactant in advance, mix and disperse it, and make it into a state (e.g., slurry or mud) that can be introduced by the surfactant introduction system.

In the case of producing an ammonia mixed fuel in each case where the combustion improver is a combination of a plurality of the above (a) to (c) as described above, when each raw material component is introduced into the mixing sealed container 16, if the discharge is due to the saturated vapor pressure in the raw material storage sealed container or if the liquid feed pump is not particularly high lift, it is advantageous to introduce all the objects to be introduced into the mixing sealed container, including ammonia and the combustion improver, in order from the object with the lowest saturated vapor pressure at the temperature inside the mixing sealed container. Specifically, it is as follows. That is, first, the raw material alcohol, naphtha, gasoline, kerosene, light oil, and their component hydrocarbons, and surfactants, which are liquids with low saturated vapor pressures near room temperature (25°C), are introduced into the mixing sealed container 16 using the liquid feed pump before ammonia, liquefied petroleum gas, and their component hydrocarbons, which have high saturated vapor pressures near room temperature (25°C). Before and after the introduction of these predetermined amounts, the regulating valves 20b ₂ , 20c ₂ , 28b, and 28c are opened and closed, and during the introduction, the respective introduction amounts are controlled to be the predetermined amounts. Next, after the inside of the mixing sealed container 16 is sufficiently cooled by the temperature control mechanism, the liquefied gases liquefied ammonia, liquefied petroleum gas, and their component hydrocarbons are introduced into the mixing sealed container 16 by discharging them at their own saturated vapor pressures in order of the lowest saturated vapor pressure at the set temperature. At that time, the gas phase in the mixing sealed container 16 is replaced in advance with the vaporized gas of the liquefied gas with the lowest saturated vapor pressure, which is introduced first. Before and after the introduction of these predetermined amounts, the regulating valves 18b, 18c, 20b ₁ , and 20c ₁ are opened and closed, and during the introduction, the respective introduction amounts are controlled to be the predetermined amounts. In addition, when the surfactant is in a solid or nearly solid state and difficult to introduce by itself, it is preferable to introduce it into the mixing closed vessel 16 in a slurried or muddy state by adding any one of the raw materials liquefied ammonia, liquefied petroleum gas, naphtha, gasoline, kerosene, light oil, and their component hydrocarbons, and in that case, a fixed amount is introduced in conjunction with the introduction of the raw material system common to the fluidizing medium, liquefied ammonia, liquefied petroleum gas, naphtha, gasoline, kerosene, light oil, and their component hydrocarbons. After the introduction of the fixed amounts of the above raw materials is completed and all the control valves are closed, the liquid phase inside the mixing closed vessel 16 is stirred by the stirrer 24 while the temperature is controlled by the temperature control mechanism so as to be maintained within a preferred temperature range, and an ammonia-mixed fuel is produced.
In any of the above cases where the combustion improver is a combination of a plurality of the above (a) to (c), the constant amount introduction mechanism and the temperature adjustment mechanism are configured in the same manner as described in the explanation of Fig. 2, and constant amount introduction and temperature adjustment are performed based on a control signal from the control device 32. Thereafter, temperature control is further performed based on a control signal generated by the control device 32 so that the temperature is appropriately maintained within an appropriate temperature range according to the liquid phase composition of the mixture, thereby making it possible to produce an ammonia mixed fuel in which the combustion improver is stably and uniformly dispersed throughout.

In addition, when the ammonia mixed fuel is produced in each case where the combustion improver is a combination of the above-mentioned (a) to (c), when the production apparatus of FIG. 7 is used, the composition change of the discharged liquid phase described above progresses when the liquid phase portion of the emulsified mixture is discharged from the liquid phase discharge line 22. That is, with the discharge of the liquid phase, the gas-liquid interface of the mixture in the mixing closed vessel 16 descends, and evaporation (boiling) of the mixture from the liquid phase to the gas phase occurs. At that time, the composition of the evaporated gas becomes complex because various combustion improvers coexist (the components contained in the evaporated gas are mainly a mixed gas of ammonia and liquefied petroleum gas or its component hydrocarbon species and/or raw material alcohol), but the composition of the evaporated gas and the liquid phase are different, as in the case of using various combustion improvers described above, and the liquid phase composition changes with the progress of the discharge of these components in the liquid phase.
In contrast, if a manufacturing apparatus in which the nitrogen gas introduction line 30b of the manufacturing apparatus 10 in Fig. 4 is provided in accordance with the configuration of the manufacturing apparatus 10 in Fig. 7 is used, the above-mentioned composition change in the discharged liquid phase can be suppressed by pressurizing and introducing nitrogen into the gas phase in the sealed mixing vessel 16, and the discharged liquid phase can be rapidly discharged as an ammonia mixed fuel. In addition, if a manufacturing apparatus in which the continuous quantitative introduction mechanism of the raw material of the manufacturing apparatus 10 in Fig. 5 is provided in accordance with the configuration of the manufacturing apparatus 10 in Fig. 7 is used, the raw material liquefied ammonia, various combustion improvers, and surfactants can be continuously introduced in a constant amount at a flow rate equal to the respective discharge flow rates of the ammonia, various combustion improvers, and surfactants in the discharged liquid phase (the pumps for sending these liquids are selected to have the high heads described above), and the discharged liquid phase can be continuously discharged as an ammonia mixed fuel without causing the above-mentioned composition change.
As described above, in the production of ammonia mixed fuel in each case where the combustion improver is a combination of a plurality of the above (a) to (c), the production apparatus 10 in Fig. 7 and the production apparatus in which the production apparatus 10 in Fig. 7 is added with the functions of the production apparatus 10 in Fig. 4 to Fig. 5 can produce the ammonia mixed fuel with the respective benefits. In this case, the introduction of the liquefied ammonia, the combustion improver, and the surfactant, the temperature adjustment during stirring and mixing, and a series of controls including the above are also performed based on the control signal of the control device 32.

In the above, the ammonia introduction line 18, the liquid phase discharge line 22, and the mixing sealed container 16 of the manufacturing apparatus 10, and the parts that come into contact with the ammonia-containing fluid (piping, containers, adjustment valves, agitators, coolers, and other equipment, and the quantitative introduction mechanism) are made of materials that are durable against ammonia. For example, copper and alloys containing copper such as cupro-nickel and brass, aluminum and alloys containing aluminum such as duralumin, and zinc and alloys containing zinc such as galvanized iron are not preferable in terms of corrosion resistance to ammonia. In addition, iron or steel is also prone to stress corrosion cracking, especially when the carbon content is high, so when adopting it, it is necessary to select a material with a low carbon content and confirmed durability against ammonia. Usable materials include, for example, iron or steel materials that have been recognized as being durable against ammonia, austenitic stainless steel (however, stainless steel with a relatively high nickel content is said to be prone to stress corrosion cracking by ammonia, and caution is required), ceramics such as glass and quartz, and plastics and rubbers such as polyethylene, polypropylene, polytetrafluoroethylene, chloroprene rubber, and perfluoroelastomer. These materials have excellent corrosion resistance at temperatures of about 60°C or less and can be used favorably. When mixing and stirring in the sealed mixing vessel 16, if liquid ammonia (liquefied ammonia) or liquefied feedstock hydrocarbons are used, cavitation may easily occur, so it is preferable to use a material for the agitator 24 that is resistant to erosion caused by cavitation.

According to one embodiment of the manufacturing apparatus 10, the sealed mixing container 16 is preferably provided with a mixing state evaluation device (FIG. 2 shows a sight glass 29 described below as an example, and other devices are not shown) configured to evaluate the mixing state of the mixture. In this case, it is preferable that the control device 32 adjusts the strength of the stirring and mixing by the agitator 24 and the stirring and mixing time according to the evaluation result of the mixing state evaluation device. In this case, the control device 32 is a stirring adjustment device that adjusts the strength of the stirring and mixing and the stirring and mixing time.
The mixed state evaluation device may be, for example, a device having at least pressure-resistant sight glasses 29 (sight windows) provided at the upper and lower layers, or a fiberscope, and a monitor that displays the state of the liquid through the pressure-resistant sight glasses or fiberscope, which can observe whether the internal mixture is separated into two phases or is in an emulsion state. Also, as the mixed state evaluation device, a measuring instrument that evaluates the difference in physical properties such as turbidity, dielectric constant, and refractive index of at least the upper and lower layers of the liquid inside the mixing sealed container 16 can be used. Furthermore, in addition to the above-mentioned device configuration, the mixed state evaluation device may also be equipped with a microscope that can observe the micro-dispersion state of the mixture, and an automatic recognition evaluation device using artificial intelligence (AI) technology. However, when the gas-liquid equilibrium data is known and a raw material system having a compatible composition and temperature condition is used, for example, when ammonia and a raw material alcohol having a carbon number of 3 or less are mixed without adding a raw material hydrocarbon, and it is known in advance that the mixture will be almost uniformly compatible or emulsified, the mixed state evaluation device may not be required.

In addition, when liquefied ammonia is introduced into the mixing sealed vessel 16, as shown in FIG. 7, it is preferable that a temperature adjustment device 18e configured to adjust the temperature of the liquid state ammonia passing through the ammonia introduction line 18 to the same temperature as the internal temperature of the mixing sealed vessel 16 is provided in the ammonia introduction line 18.
In addition, when the liquefied petroleum gas and its component hydrocarbons are introduced into the mixing sealed vessel 16 through the combustion improver introduction line _20-1 , it is preferable that a temperature control device 20e- ₁ configured to adjust the temperature of the combustion improver passing through the combustion improver introduction line _20-1 to the same temperature as the internal temperature of the mixing sealed vessel 16 is provided in the combustion improver introduction line _20-1 as shown in FIG. 7. These temperature control devices are composed of, for example, a heat exchanger or a Peltier element. When these liquefied gas raw materials are introduced, the internal pressure of the mixing sealed vessel 16 is adjusted by the above-mentioned temperature control mechanism so as to be lower than the saturated vapor pressure in the storage sealed vessels 12 and _14-1 of the liquefied ammonia and liquefied petroleum gas or its component hydrocarbons, and in many cases, this is substantially cooling to a temperature lower than the external environment. Therefore, the temperature control of each introduction line by the above-mentioned temperature control device also often results in cooling to a temperature lower than the external environment.
As a result, when these liquefied gas raw materials are introduced into the mixing sealed container 16, the internal temperature is not increased, and therefore unnecessary vaporization of the mixture within the mixing sealed container 16 and an increase in the saturated vapor pressure can be suppressed.
Furthermore, when no liquid feed pump is provided at the time of introduction, if the temperature of the external environment is too low and the saturated vapor pressure inside the ammonia storage sealed container 12 and/or the combustion improver storage sealed container 14 ₁ is insufficient for introduction into the mixing sealed container 16, the saturated vapor pressure can be increased by providing the ammonia storage sealed container 12 and/or the combustion improver storage sealed container 14 with heating devices 13 and/or 15 and appropriately heating them. As the heating devices 13 and 15, for example, an electric heater or a thermostatic bath containing a heating medium whose temperature is appropriately adjusted is used.
The temperature control by the above-mentioned temperature control mechanism provided in the mixing sealed container 16, and the temperature control devices 18e, _20e1 provided in the introduction lines 18, ₂₀₁ , and further the heating by the heating devices 13 and ₁₅ provided in the storage sealed containers 12, 141, respectively, are controlled by the control device 32 based on the results of the thermometers 33, 18f and _20f1 provided in the mixing sealed container 16 and the introduction lines 18, ₂₀₁ , respectively.

FIG. 8 is a block diagram of an example of a main part of the manufacturing apparatus 10 of one embodiment. As shown in FIG. 8, the manufacturing apparatus 10 includes a storage sealed container 50 for ammonia mixed fuel configured to store the ammonia mixed fuel in a gas-liquid equilibrium state. The storage sealed container 50 includes an inlet 52 through which the ammonia mixed fuel is injected, and an outlet 54 provided in the lower part, preferably on the bottom surface, of the storage sealed container 50 configured to discharge the ammonia mixed fuel in a liquid state to the outside. The inlet 52 is provided with a connection mechanism 56 configured to inject the ammonia mixed fuel from the liquid phase discharge line 22 into the storage sealed container 50 while maintaining airtightness and internal pressure. As an airtight structure, the inlet 52 is provided with a sealing mechanism (not shown) using a gasket or an O-ring or the like. The inner wall of the storage sealed container 50 comes into contact with ammonia, similar to the mixing sealed container 16, so that the storage sealed container 50 and the connection mechanism 56 are made of a material having corrosion resistance against ammonia.
An ammonia mixed fuel supply line 60 that discharges the ammonia mixed fuel in a liquefied state to the outside is connected to the discharge port 54. The ammonia mixed fuel supply line 60 is provided with a discharge valve 58 that controls the supply amount of the ammonia mixed fuel by the control device 32.

When the ammonia mixed fuel is introduced from the mixing sealed container 16 into the storage sealed container 50 and filled, in order to prevent the inclusion of air or the like that was present in the storage sealed container 50, the remaining air or the like in the storage sealed container 50 must be exhausted in advance by vacuum exhaust through the gas phase exhaust line 59 or replaced with the volatilized vapor of the ammonia mixed fuel. In the former case, a vacuum pump (not shown) is connected to the ammonia mixed fuel supply line 60, the exhaust valve 58 is opened while the liquid phase exhaust valve 22a is closed, and the storage sealed container 50 is evacuated by the vacuum pump until the internal pressure of the storage sealed container 50 is about 0.01 MPa or less, and then the exhaust valve 58 is closed. Thereafter, the liquid phase exhaust valve 22a is opened, and the storage sealed container 50 is filled with the ammonia mixed fuel. In the latter case, in addition to the configuration of Fig. 9, it is preferable to provide a gas phase discharge line 59 (gas phase discharge valve 59a is provided in the gas phase discharge line 59) for discharging the gas in the gas phase part in the storage sealed container 50 to the upper part, preferably on the top surface, as shown in Fig. 10 described later. At this time, while keeping the liquid phase discharge valve 22a closed, the gas phase discharge valve 59a is opened, and then the liquid phase discharge valve 22a is slightly opened to introduce a small amount of ammonia mixed fuel into the storage sealed container 50, and the remaining air, etc. in the storage sealed container 50 is purged by the vaporized steam, and then the gas phase discharge valve 59a is closed, thereby replacing the gas in the storage sealed container 50. Thereafter, the liquid phase discharge valve 22a is opened, and the ammonia mixed fuel is filled into the storage sealed container 50.
When the above-mentioned ammonia mixed fuel is filled, it is preferable that a temperature control device (not shown) described later is provided, and the inside of the sealed storage container 50 can be sufficiently cooled so that the saturated vapor pressure inside is about 0.05 to 0.1 MPa or less so as to increase the filling amount into the sealed storage container 50 (reduce the volume of the gas phase portion after filling). As a result, the ammonia mixed fuel can be efficiently filled into the sealed storage container 50 through the liquid phase discharge line 22 by discharge based on the saturated vapor pressure of the ammonia mixed fuel in the sealed storage container 16.

In one embodiment, the sealed storage container 50 of the manufacturing apparatus 10 is preferably provided with an agitator 63 configured to agitate and mix the ammonia mixed fuel, as shown in FIG. 8.

The storage sealed container 50 of the manufacturing apparatus 10 according to one embodiment is provided with a temperature control device (not shown) configured to appropriately control the temperature of the ammonia mixed fuel inside the storage sealed container 50. Examples of the temperature control device include a heat exchanger that controls the temperature of the mixing sealed container 16 by flowing a temperature control medium, or a Peltier element. The temperature control by the temperature control device is controlled by a control signal generated by the control device 32 based on the temperature measurement value of a thermometer 61 that measures the liquid phase temperature inside the storage sealed container 50.
This temperature control device has the following three functions, similar to the temperature control mechanism in the above-mentioned mixing sealed container 16. The first function is cooling control of the internal temperature so that the internal pressure of the storage sealed container 50 is within a temperature range that does not exceed the set withstand pressure. During this temperature control, when the control device 32 predicts that the internal pressure measurement value of the pressure gauge 62 that measures the internal pressure inside the storage sealed container 50 will reach the withstand pressure level, the storage sealed container 50 is quickly cooled by the temperature control device based on a control signal generated by the control device 32.
The second is the cooling control for reducing the internal pressure of the storage sealed container 50 so that the ammonia mixed fuel can be filled efficiently and smoothly, as described above.
The third is a control to adjust the temperature of the mixture so that the entire liquid phase portion of the mixture of ammonia and the combustion improver in the sealed storage container 50, which maintains a gas-liquid equilibrium state, is in a temperature range in which the ammonia and the combustion improver are in a solution state in which the ammonia and the combustion improver are dissolved in each other, or in an emulsion state of the ammonia and the combustion improver, depending on the liquid phase composition of the mixture. For this purpose, it is preferable that the sealed storage container 50 is equipped with both the temperature adjustment device and the agitator 63, and that when the ammonia mixed fuel in the sealed storage container 50 is stirred and mixed by the agitator 63, the temperature adjustment device is configured to adjust the temperature of the ammonia mixed fuel so that the entire liquid phase portion of the ammonia mixed fuel is in a temperature range in which the ammonia and the combustion improver are in a solution state in which the ammonia and the combustion improver are dissolved in each other, or in an emulsion state of the ammonia and the combustion improver, depending on the liquid phase composition of the ammonia mixed fuel. Here, as the "temperature range in which the ammonia and the combustion improver are in a mutually dissolved solution state, or in which the ammonia and the combustion improver are in an emulsion state," a temperature range suitable for homogenization by mutual dissolution or emulsification in the ammonia mixed fuel of each mixed raw material system described above is selected. This temperature control is also performed by the temperature adjustment device based on a control signal generated by the control device 32 in accordance with the temperature measurement value by the thermometer 61.
When the ammonia mixed fuel is discharged from the mixing sealed container 16 and filled into the storage sealed container 50, the entire ammonia mixed fuel filled is in a uniform and homogeneous solution state or a uniform emulsion state (not separated into upper and lower layers) regardless of the type of combustion improver contained therein. The temperature inside the storage sealed container 50 is maintained equal to the liquid phase temperature inside the mixing sealed container 16, so that the above-mentioned uniform and homogeneous solution state or uniform emulsion state can be maintained. Even if the above-mentioned stirring and mixing and temperature adjustment are stopped for a certain period after the ammonia mixed fuel is filled into the storage sealed container 50, the ammonia mixed fuel can be restored to a uniform and homogeneous solution state or uniform emulsion state by performing stirring and mixing and temperature adjustment to the same temperature as when the ammonia mixed fuel was filled again before the ammonia mixed fuel is subjected to combustion.

In addition, when discharging the ammonia mixed fuel from the storage sealed container 50, the composition change of the mixed fuel occurs as explained in the case of discharging from the mixing sealed container. In order to suppress this composition change, the storage sealed container 50 of the manufacturing apparatus 10 of another embodiment is provided with a nitrogen gas injection line 64 having a configuration similar to the nitrogen gas introduction line 30b shown in FIG. 4 described above, and a gas phase discharge line 59 (a gas phase discharge valve 59a is provided on the gas phase discharge line 59) that discharges the gas in the gas phase part in the storage sealed container 50 to the upper part, preferably on the top surface, of the storage sealed container 50, as shown in FIG. 9.
With the above-mentioned configuration, it is possible to quickly discharge the ammonia mixed fuel while suppressing the change in the liquid phase composition caused by the progress of evaporation of the mixture in the sealed storage container 50 accompanying the discharge of the ammonia mixed fuel, as described above.
The nitrogen gas injection line 64 is led from a storage container (not shown) such as a general pressurized nitrogen gas cylinder filled to an internal pressure of about 10 to 15 MPa. The nitrogen gas injection line 64 is provided with a pressure reducing valve 64a, a pressure gauge 64b, and an adjustment valve 64c between the upstream side and the mixing sealed container 16. The nitrogen gas led through the nitrogen gas injection line 64 is reduced in pressure by the pressure reducing valve 64a so that the indication value of the pressure gauge 64b becomes a predetermined pressure (for example, the saturated vapor pressure + about 0.05 to 0.1 MPa) equal to or higher than the saturated vapor pressure of the mixture in the storage sealed container 50 (the indication value of the pressure gauge 62). When the liquid phase of the mixture is discharged from the storage sealed container 50, the adjustment valve 64c is opened in conjunction with the opening of the discharge valve 58, and the ammonia mixed fuel is discharged to the ammonia mixed fuel supply line 60 in a form forcibly pushed out by the nitrogen gas injected from the gas phase side. The operation of these series of valves is controlled by a control signal sent by the control device 32. As described above, when the ammonia mixed fuel is discharged from the storage sealed container 50, nitrogen gas is pressurized and injected into the gas phase part in the storage sealed container 50, similar to the case of discharging the ammonia mixed fuel from the mixing sealed container 16 shown in Fig. 4, so that the composition change is substantially reduced and the fuel is quickly discharged. When the ammonia mixed fuel is again injected from the mixing sealed container 16 into the storage sealed container 50 through the liquid phase discharge line 22, the gas phase discharge valve 59a is opened in advance, the liquid phase discharge valve 22a is slightly opened to introduce a small amount of ammonia mixed fuel into the storage sealed container 50, and the gas (air, nitrogen, etc.) in the storage sealed container 50 is purged by the vaporized steam, and then the gas phase discharge valve 59a is closed, so that the gas in the storage sealed container 50 is replaced with gas.

In another embodiment of the manufacturing apparatus 10, the bottom surface of the sealed storage container 50 is provided with the outlet 54, and the outlet 54 is provided with a volumetric flowmeter 65 configured to continuously measure the discharge volumetric flow rate of the ammonia mixed fuel discharged in liquid phase from the outlet 54. Furthermore, when the ammonia mixed fuel is injected into the sealed storage container 50 through the inlet 52, the ammonia mixed fuel is injected until it reaches a predetermined full-fill amount or a predetermined amount less than the full-fill amount, and when the ammonia mixed fuel is discharged from the sealed storage container 50 through the outlet 54, the injection and discharge control mechanism is configured to continuously reduce the internal volume of the sealed storage container 50 at a volumetric change rate approximately equal to the discharge volumetric flow rate measured by the volumetric flowmeter 65 while maintaining the airtightness and internal pressure of the sealed storage container 50.
The reason why the composition change occurs when the ammonia mixed fuel is discharged is that, as described above for the similar situation in the mixing sealed container 16, the volume of the gas phase portion in the storage sealed container 50 increases by the volume of the discharged liquid phase with the discharge of the ammonia mixed fuel, and the internal pressure decreases, so that the ammonia mixed fuel evaporates (boils) from the liquid phase to the gas phase in the storage sealed container 50, and the composition of the vapor at that time is different from the liquid phase composition. Therefore, if the volume of the gas phase portion and the internal pressure are maintained so that the gas-liquid equilibrium state in the storage sealed container 50 is maintained even during the discharge of the liquid phase, the evaporation does not occur and the composition of the discharged ammonia mixed fuel is kept constant. Therefore, as described above, if the injection and discharge control mechanism is provided that continuously reduces the internal volume of the storage sealed container 50 at a volume change rate equal to the discharge volumetric flow rate measured by the volumetric flow meter 65 while maintaining the airtightness and internal pressure of the storage sealed container 50 when the ammonia mixed fuel is discharged from the storage sealed container 50, the ammonia mixed fuel can be discharged while keeping the discharge composition constant.

10 shows an embodiment of a manufacturing apparatus 10 provided with an example of the injection and discharge control mechanism that falls within the scope of the above-mentioned embodiment. The storage sealed container 50 includes a cylinder 66 formed of a body (e.g., cylindrical) having an upright outer cylinder shape and a constant internal cross-sectional area perpendicular to the axial direction of the outer cylinder, and a bottom plate provided with an injection port 52 and a discharge port 54 that seals the lower end opening of the body, a piston 67 that can reciprocate up and down within the cylinder 66 while maintaining airtightness, and a reciprocating drive device 68 configured to reciprocate the piston 67 up and down.
Here, the injection and discharge control mechanism is configured to perform the following control. That is, when the ammonia mixed fuel is injected into the storage sealed container 50 through the injection port 52, the lower surface of the piston 67 is pushed up in the cylinder 66 by the reciprocating drive device 68 to a full-fill position (hereinafter referred to as H position) or a predetermined position below the full-fill position, and then stops. At that time, it is preferable that the mixing sealed container 16 and the cylinder 66 are relatively disposed so that the H position is approximately at the height of the gas-liquid interface of the ammonia mixed fuel in the mixing sealed container 16. In this state, the ammonia mixed fuel is stored in the cylinder 66.
After the ammonia mixed fuel is filled, when the ammonia mixed fuel is discharged from the sealed storage container 50 through the discharge port 54, the piston 67 is continuously pushed down by the reciprocating drive device 68 at a linear velocity approximately equal to a value calculated by dividing the discharge volumetric flow rate measured by the volumetric flow meter 65 by the internal cross-sectional area of the body of the cylinder 66 while resisting the saturated vapor pressure (equal to the internal pressure) of the ammonia mixed fuel in the sealed storage container 50 measured by the pressure gauge 62, and then the lower surface of the piston 67 stops at a discharge end position (hereinafter referred to as L position) near the bottom plate of the cylinder 66. During this discharge, the product of the internal cross-sectional area and the linear velocity is approximately equal to the discharge volumetric flow rate, so that the internal volume of the sealed storage container 50 can be continuously reduced at the volume change speed approximately equal to the discharge volumetric flow rate as described above, and as a result, the ammonia mixed fuel can be discharged while suppressing composition change.

In the embodiment of Fig. 10, the body and bottom plate of the storage sealed container 50 are the cylinder 66, and the upper surface of the cylinder 66 is the piston 67 that reciprocates, so it is preferable that there are no obstacles on the lower surface of the piston 67 or inside the cylinder 66 that would impede the reciprocating movement of the piston 67. For this reason, as shown in Fig. 11, the conduit (sheath, etc.) of the thermometer 61 and the conduit of the pressure gauge 62 are installed on the inner surface of the lowest part of the body of the cylinder 66 or the inner surface of the bottom surface so that the tips of the conduits are flush with each other. At this time, the inner wall of the surrounding cylinder 66 is countersunk so that the temperature measuring part at the tip of the conduit (sheath, etc.) of the thermometer 61 is in contact with the liquid. If it is necessary to increase the accuracy of the conduit of the pressure gauge 62, it is preferable that the pressure gauge side is extended so as to be located above the gas-liquid interface of the ammonia mixed fuel, and the influence of the liquid column pressure is eliminated. In addition, when the agitator 63 is installed, it is preferable to provide a counterbore in the bottom plate facing downward so that the working parts such as the agitator blades are located below the bottom surface of the cylinder 66, or to provide a circulation pipe (not shown) for extracting the ammonia mixed fuel inside the cylinder 66 to the outside and circulating it back inside again, and to place the working parts of the agitator 63 inside the circulation pipe. Furthermore, it is preferable that the inlet 52 and the outlet 54 are provided on the bottom surface of the cylinder 66 so that they are not blocked by the reciprocating movement of the piston 67.
10, the piston 67 is raised and lowered (reciprocated) by a reciprocating drive device 68 including a motor 68a and a crank mechanism 68b, the output and rotation speed of which are variable. In the reciprocating drive device 68 of this example, the rotation of the motor 68a is decelerated by a reduction gear and then transmitted to the crank mechanism 68b, but the present invention is not limited to this. The reciprocating drive device 68 is appropriately designed according to the output characteristics of the motor 68a, the saturated vapor pressure of the ammonia mixed fuel (measurement value of the pressure gauge 62), the required variable range of the raising and lowering (reciprocating) speed of the piston 67 accompanying injection and discharge, the required accuracy of the raising and lowering (reciprocating) stop position, and the like.
The piston 67 can move up and down (reciprocate) by rotating the crank of the crank mechanism 68b half a turn in the forward and reverse directions in the range from the upward position to the downward position. At this time, the H position and the L position of the piston 67 are set to the top dead center of the piston 67 or slightly below the top dead center, and the bottom dead center or slightly above the bottom dead center, respectively. The H position and the L position are calibrated and recognized by a position sensor that detects the position of the piston 67 or the crank of the crank mechanism 68b, an angle sensor that detects the rotation angle of the motor 68a, or the like (not shown), and when the piston 67 reaches the H position or the L position, the power supply to the motor 68a is cut off, and the motor 68a is forcibly stopped, preferably by a brake mechanism not shown.
At the start of injection of the ammonia mixed fuel, the piston 67 is at point L, and after the liquid phase discharge valve 22a is opened, the piston 67 rises to point H or a predetermined position below point H at a linear velocity such that the measured value of the pressure gauge 62 remains substantially constant, and the ammonia mixed fuel is injected and filled inside the cylinder 66, and then the liquid phase discharge valve 22a is closed, and the ammonia mixed fuel is stored in that state. After that, when the discharge valve 58 is opened and the ammonia mixed fuel is discharged, the motor 68a is driven at a rotational speed such that the descending speed of the piston 67 near the center between points H and L is substantially equal to the linear speed calculated from the discharge flow rate value measured by the volumetric flow meter 65, and is stopped when the piston 67 reaches the L position. The above series of operations are controlled by a control signal from the control device 32.
In this embodiment, the reciprocating drive device 68 is not necessarily limited to the above-mentioned crank mechanism 68b, and other reciprocating drive devices such as a rack and pinion mechanism, a ball screw mechanism, or a feed screw mechanism can also be used.

In another embodiment of the manufacturing apparatus 10 including the sealed storage container 50, the manufacturing apparatus 10 further includes an injection and discharge control mechanism configured such that, when the ammonia mixed fuel is injected into the sealed storage container 50 through the injection port 52, the ammonia mixed fuel is injected until a predetermined full-fill amount or a predetermined amount less than the full-fill amount is reached, and, when the ammonia mixed fuel is discharged from the sealed storage container 50 through the discharge port 54 after the injection of the ammonia mixed fuel into the sealed storage container 50, the ammonia mixed fuel is pushed out of the sealed storage container 50 at a pressure higher than the saturated vapor pressure of the ammonia mixed fuel at the temperature of the ammonia mixed fuel in the sealed storage container 50 while maintaining the airtightness of the sealed storage container 50.
According to the above-mentioned configuration, the ammonia mixed fuel in the storage sealed container 50 is compressed at a pressure exceeding its saturated vapor pressure during the discharge process, so that the gas phase portion disappears and the whole becomes liquid and is discharged from the discharge port 54. Therefore, evaporation (boiling) does not occur during the discharge process, so that the discharge can be performed at a high pressure equal to or higher than the saturated vapor pressure without causing the above-mentioned change in the discharge composition.

Fig. 11 shows an embodiment of a manufacturing apparatus 10 provided with an example of the injection and discharge control mechanism that falls within the scope of the above-mentioned embodiment. The embodiment of Fig. 11 has substantially the same configuration as the above-mentioned embodiment shown in Fig. 10 (e.g., a reciprocating drive device 68 having a motor 68a and a crank mechanism 68b of a common operating mechanism, etc.), so that the corresponding components are given the same symbols as in Fig. 10, and in the following, descriptions common to the manufacturing apparatus 10 of Fig. 10 will be omitted.
In the manufacturing apparatus 10 of FIG. 11, when the ammonia mixed fuel is injected and filled, the injection and filling are performed by the same operation as in the manufacturing apparatus 10 of FIG. 10, and the ammonia mixed fuel is stored in that state. When the motor 68a gradually lowers the piston 67, the initial value (=saturated vapor pressure) of the pressure gauge 62 before the start of the descent is maintained for a while, and then the internal pressure begins to rise when the gas phase in the cylinder 66 disappears. While the piston 67 is further lowered, when the measurement value of the pressure gauge 62 reaches a predetermined pressure value that does not exceed the withstand pressure of the storage airtight container 50, the discharge valve 58 is opened at a predetermined opening, and the ammonia mixed fuel is discharged. If the opening degree of the discharge valve 58 and the descending speed of the piston 67 are adjusted so that the measurement value of the pressure gauge 62 maintains the predetermined pressure during the discharge, the discharge flow rate (measured by the volumetric flow meter 65) of the ammonia mixed fuel led to the ammonia mixed fuel supply line 60 through the discharge port 54 can be changed. The above series of operations are controlled by a control signal from the control device 32.

In this embodiment, components such as the storage sealed container 50 (cylinder 66 and piston 67) and the pressure gauge 62 may be subject to sudden pressure fluctuations before and after the gas phase disappears, and therefore must have a pressure resistance and structure that can withstand this.
In addition to the configuration of the storage sealed container 50 of this embodiment, the configuration of the mixing sealed container 16 equipped with a continuous quantitative introduction mechanism of the raw material described in the embodiment of FIG. 5 above can also be provided. In that case, it is preferable that the above-mentioned H point and L point are adjusted to be the top dead center and bottom dead center of the piston 67, respectively, and that the discharge valve 58 and the liquid phase discharge valve 22a are configured to be opened and closed at appropriate openings in conjunction with the continuous up and down (reciprocation) of the piston 67 by the crank mechanism 68b rotating at a constant speed. This makes it possible to continuously discharge the ammonia mixed fuel by pressurizing it to a saturated vapor pressure or higher using the storage sealed container 50 of this embodiment while continuously producing the ammonia mixed fuel using the mixing sealed container 16 of FIG. 5. At this time, the storage sealed container 50 of this embodiment is functionally equivalent to a so-called plunger pump.
In addition, in the case where the continuous quantitative introduction mechanism for raw material shown in FIG. 5 is not provided, even in this embodiment, the reciprocating drive device 68 is not necessarily limited to the crank mechanism 68b described above, and other reciprocating drive devices such as a rack and pinion mechanism, a ball screw mechanism, or a feed screw mechanism may be used.
In addition, in the present embodiment described above, since the gas phase disappears within the cylinder 66 during the discharge process, it is possible to generally achieve the above-mentioned functions not only in a configuration in which the cylinder 66 is upright as shown in FIG. 11, but also in a configuration in which the cylinder is tilted sideways at an angle of 90 degrees, for example.

Furthermore, as shown in FIG. 12, the storage sealed container 50 of the manufacturing apparatus 10 of the embodiment is preferably provided with a mixed state evaluation device 6 9 configured to evaluate the mixed state of the ammonia mixed fuel, similar to the mixed state evaluation device described in the mixing sealed container 16. FIG. 12 is a block diagram of an example of a main part of the manufacturing apparatus 10 of the embodiment. Based on the evaluation result of the mixed state obtained by the mixed state evaluation device 6 9 , the control device 32 generates a control signal for adjusting the strength and time of the stirring and mixing by the stirrer 63, and the stirrer 63 stirs based on this control signal. In particular, the ammonia mixed fuel obtained by emulsifying ammonia in a liquid state and feedstock hydrocarbons may be re-separated over time during storage in the storage sealed container 50. In this case, the ammonia mixed fuel can be re-emulsified before being supplied to a combustor or the like by re-stirring the ammonia mixed fuel with the stirrer 63.

The connection mechanism 56 (see Figures 8 to 11) of the manufacturing apparatus 10 of one embodiment is configured so that the inlet line and the inlet 52 for introducing the ammonia mixed fuel into the storage sealed container 50 can be detached from each other, and the storage sealed container 50 is a container that can be mounted on a transportation device (not shown) in any one of land, water, and airspace. For example, in the case of the embodiment shown in Figure 8, the inlet line connected to the storage sealed container 50 is the liquid phase discharge line 22 extending from the mixing sealed container 16, but this inlet line may extend from another temporary storage container (not shown) that temporarily stores the ammonia mixed fuel manufactured by the manufacturing apparatus 10. The configuration of this temporary storage container is basically the same as any of the configurations of the storage sealed containers described so far. The transport equipment includes, for example, vehicles (small/large automobiles, motorbikes, etc.) including tank trucks capable of transporting ammonia and ammonia mixed fuel on land, railroad cars, etc., ships in general, such as merchant ships, passenger ships, warships, and various work ships, including ships for transporting liquefied ammonia, submarines, etc., in water areas, and helicopters, aircraft, airships, drones, etc. in airspace. The storage sealed container 50 has a size and structure that allows it to be moved or transported. According to the above configuration, the storage sealed container 50 after being filled with ammonia mixed fuel is detached by the detachable connecting mechanism 56 and mounted on the transport equipment, or the storage sealed container 50 is installed on the transport equipment in advance, filled with ammonia mixed fuel, and then detached by the detachable connecting mechanism 56, so that the ammonia mixed fuel produced by the production device 10 can be efficiently loaded onto the transport equipment and transported.

(Ammonia mixed fuel supply device)
13A and 13B are block diagrams illustrating an example of the configuration of an ammonia mixed fuel supply device 70 according to one embodiment.
A supply device 70 (enclosed by a dashed line) shown in Fig. 13(a) includes at least the above-mentioned ammonia mixed fuel production device 10 and an ammonia mixed fuel supply line 60. In Fig. 13(a), for the sake of simplicity, only the mixing sealed container 16 and the storage sealed container 50 are shown. The ammonia mixed fuel supply line 60 supplies the ammonia mixed fuel discharged from the exhaust port 54 of the storage sealed container 50 to a combustor 100 configured to combust the ammonia mixed fuel. The ammonia mixed fuel stored in the storage sealed container 50 is produced in the mixing sealed container 16 and then transferred to the storage sealed container 50 via the liquid phase discharge line 22.
A supply device 70 (area surrounded by a dashed line) shown in Fig. 13(b) also includes at least the above-mentioned production device 10 for ammonia mixed fuel and an ammonia mixed fuel supply line 60. The embodiment shown in Fig. 13(b) includes a mixing sealed container 16 as the production device 10, but does not include a storage sealed container 50. A part of the ammonia mixed fuel supply line 60 becomes a liquid phase discharge line 22 for the mixing sealed container 16. That is, the ammonia mixed fuel discharged from the mixing sealed container 16 is supplied to the combustor 100 configured to combust the ammonia mixed fuel through the ammonia mixed fuel supply line 60 without passing through the storage sealed container 50.

13(a) and 13(b), an ammonia mixed fuel supplying device 80 is provided on the ammonia mixed fuel supplying line 60. The ammonia mixed fuel supplying device 80 is configured to supply the ammonia mixed fuel to the combustor 100 at a predetermined flow rate and a predetermined discharge pressure. The ammonia mixed fuel supplying device 80 includes, for example, a pressurizer or a liquid feed pump (which may be, for example, the storage sealed container 50 shown in FIG. 11 described above) that boosts the ammonia mixed fuel to a pressure required by the combustor 100 and supplies the ammonia mixed fuel by controlling the flow rate, as necessary, and an injector that discharges the ammonia mixed fuel into the combustor 100. These are not shown.
The combustor 100 is, for example, a direct injection type combustor that directly supplies ammonia mixed fuel in a liquid state to a combustion chamber. A predetermined amount of air, oxygen-enriched air, oxygen gas, or the like required for combustion is separately introduced into the combustor through a separately provided introduction line (not shown). The ammonia mixed fuel is vaporized in the combustor 100, and then comes into contact with and diffuses and mixes with the air, oxygen-enriched air, oxygen gas, or the like, and is burned. The combustor may also be a combustor in which the liquid ammonia mixed fuel is prevaporized by a prevaporizer (not shown) and the gas is supplied. In this case, the vaporized ammonia mixed fuel may be premixed with air, oxygen-enriched air, or oxygen at a predetermined ratio. When the ammonia mixed fuel supplying device 80 vaporizes the ammonia mixed fuel and supplies the gas, the ammonia mixed fuel supplying device 80 may be equipped with the above prevaporizer. In the above combustor, in order to ensure smooth combustion, an ignition plug for igniting the vaporized gas of the ammonia mixed fuel or an auxiliary device such as an auxiliary burner for heating the vaporized gas of the ammonia mixed fuel to the ignition temperature or higher is appropriately provided as necessary. These are not shown in the figure.
The supply device 70 configured as above can supply the ammonia mixed fuel to the combustor 100 at a predetermined discharge pressure.

The ammonia mixed fuel supply line 60, the combustor 100, the combustion gas exhaust line (not shown) that discharges exhaust gas from the combustor 100 to the outside air, and the constituent materials around them are limited to materials that are corrosion-resistant to ammonia. In addition, for parts that come into contact with gas containing vaporized ammonia and are heated to approximately 400°C or higher by combustion heat, such as the area around the ammonia mixed fuel injector that discharges the ammonia mixed fuel into the combustor 100, the high-temperature gas contact parts that come into contact with the combustion gas inside the combustor 100, and the high-temperature parts in the combustion gas line, it is preferable that they have resistance to high-temperature corrosion due to nitriding embrittlement based on the nitrogen in ammonia, depending on the concentration of ammonia. In particular, for parts that come into contact with high-concentration ammonia gas and are heated to 400°C or higher, chromium steel alloys such as iron, steel, cast iron, or stainless steel may not have sufficient corrosion resistance. For this reason, it may be necessary to use metals such as highly corrosion-resistant pure nickel, or Inconel (trademark), Hastelloy (trademark), Nimonic (trademark), etc., which contain a high content of nickel, as materials for these parts.

FIG. 14 is a block diagram showing an example of the configuration of a supply device 70 according to an embodiment.
14 (area surrounded by a dashed line), a branching section 110 is provided on the ammonia mixed fuel supply line 60 leading to the combustor 100, which branches the ammonia mixed fuel at a predetermined ratio. The supplying device 70 includes an ammonia mixed fuel reflux line 112. The ammonia mixed fuel reflux line 112 is configured to reflux a portion of the ammonia mixed fuel flowing through the ammonia mixed fuel supply line 60 from the branching section 110, which is not supplied to the combustor 100, into the mixing sealed container 16 or the storage sealed container 50. 14, in a branching section 110 constituted by a branching valve (not shown), a part of the ammonia mixed fuel supplied by the ammonia mixed fuel supplying device 80 is branched at a predetermined flow rate and a predetermined discharge pressure required by the combustor 100, and is returned to the mixing sealed container 16 or the storage sealed container 50. In order to return the branched ammonia mixed fuel to the mixing sealed container 16 or the storage sealed container 50, it is preferable that a pressure adjustment mechanism (not shown) is provided in the ammonia mixed fuel return line 112 to adjust the branched ammonia mixed fuel to be under the same pressure condition as the ammonia mixed fuel in the mixing sealed container 16 or the storage sealed container 50. As this pressure adjustment mechanism, for example, a circulation pump or the like that can adjust the discharge pressure to be equal to the pressure in the mixing sealed container 16 or the storage sealed container 50 can be used. At the time of the branching and reflux, the control device 32 calculates the required amount of ammonia mixed fuel to be supplied to the combustion in the combustor 100 according to the required output of the combustion in the combustor 100, and transmits a control signal to the branch valve of the branching part 110 and the pressure adjustment mechanism provided in the ammonia mixed fuel reflux line 112 so as to branch the surplus amount of the ammonia mixed fuel supplied from the supply device 80 relative to this required amount at the branching part 110 and to reflux it into the mixing sealed container 16 or the storage sealed container 50 via the ammonia mixed fuel reflux line 112. Based on these control signals, the opening degree of the branch valve of the branching part 110 and the pressure adjustment mechanism are controlled. In addition, for stable operation of the above control, a flow rate adjustment valve (not shown) may be provided in the ammonia mixed fuel reflux line 112, and the opening degree of this flow rate adjustment valve is also appropriately controlled by the control signal of the control device 32 in the same manner.
According to the supply device 70 configured as described above, it is possible to continuously supply a required amount of ammonia mixed fuel to the combustor 100 at a stable predetermined discharge pressure.

(Combustion device for ammonia mixed fuel)
FIG. 15 is a block diagram illustrating an example of the configuration of an ammonia mixed fuel combustion device 120 according to one embodiment.
In this embodiment, the combustion device 120 is a device that generates thermal energy by burning the produced ammonia mixed fuel, or converts the thermal energy generated by the combustion into other energy such as mechanical energy or electrical energy, and discharges the combustion gas into the atmosphere, and each of the obtained energies can be used for various purposes described later.
The combustion device 120 includes an ammonia mixed fuel supply device 70 (see FIG. 9), a combustor 100, and a combustion gas discharge line 130.
The combustor 100 is configured to combust the ammonia fuel blend described above.
The supply device 70 is configured to supply the ammonia fuel blend to the combustor 100 as described above.
The combustion gas discharge line 130 is configured to discharge the combustion gas generated by the combustion of the ammonia mixed fuel in the combustor 100 into the atmosphere.

Furthermore, the combustion device 120 of one embodiment is equipped with a selective catalytic reactor 128 as necessary. As shown in FIG. 15, when the combustion device 120 is equipped with the selective catalytic reactor 128, the selective catalytic reactor 128 is accompanied by a nitrogen oxide and ammonia concentration measuring device 122, a supply amount calculation device 124, and a constant amount supply device 126.

In this combustion device 120, as shown in FIG. 15, it is preferable that the selective catalytic reactor 128 is provided on the exhaust side of the combustion gas of the combustor 100, i.e., in the combustion gas exhaust line 130. The selective catalytic reactor 128 is a reactor configured to decompose, by catalytic reduction, nitrogen oxides (including air pollutants such as nitric oxide and nitrogen dioxide. Hereinafter, these may be collectively referred to as NOx) in the combustion gas exhausted from the combustor 100. That is, the selective catalytic reactor 128 reduces and decomposes nitrogen oxides NOx, which are by-produced when the ammonia mixed fuel is burned in the combustor 100 and are contained in the combustion gas and are exhausted from the combustion chamber of the combustor 100 and pass through the combustion gas exhaust line 130.

Ammonia is known as a NOx reducing agent that selectively reduces and decomposes NOx with high efficiency in the presence of a suitable catalyst, and is widely used. In the selective catalytic reactor 128, as the NOx reducing agent, ammonia that is not completely burned in the combustor 100 and remains in the combustion gas and is discharged, or in addition to the ammonia, ammonia separately supplied from the above-mentioned ammonia storage sealed container 12, or ammonia mixed fuel separately supplied from the above-mentioned storage sealed container 50 can be used.
15 shows an embodiment in which the ammonia that is not completely burned in the combustor 100 and remains in the combustion gas and is discharged, and either the ammonia separately supplied from the ammonia storage sealed container 12 or the ammonia mixed fuel separately supplied from the storage sealed container 50 are used together as the reducing agent. In this embodiment, it is preferable to provide a selective catalytic reaction supply line 132 configured to merge a predetermined amount of either the liquid ammonia or the ammonia mixed fuel into the combustion gas discharge line 130. That is, the selective catalytic reaction supply line 132 is led from either the ammonia storage sealed container 12 that stores the liquid ammonia or the storage sealed container 50 that stores the ammonia mixed fuel.

In the embodiment of FIG. 15, in addition to the residual ammonia in the combustion gas discharged from the combustor 100, either liquid ammonia or ammonia in the ammonia mixed fuel is further supplied to the selective catalytic reactor 128, so that NOx coexisting in the combustion gas can be reliably reduced and decomposed. At a junction 130a of the combustion gas and either one of the ammonia, the ammonia is vaporized by the exhaust heat of the combustion gas and supplied to the selective catalytic reactor 128, where it acts as a reducing agent in the selective catalytic decomposition of NOx. In particular, when the ammonia mixed fuel is supplied for catalytic reduction, the coexisting feedstock hydrocarbon or feedstock alcohol also acts as a reducing agent in the selective catalytic reactor 128. Therefore, the nitrogen oxides NOx can be decomposed more efficiently by the synergistic effect of the reducing power of ammonia and the feedstock hydrocarbon or feedstock alcohol.
In addition, it is preferable that the catalyst in the selective catalytic reactor 128 is maintained at a predetermined temperature so that the selective catalytic reduction described above can proceed efficiently. For this reason, it is preferable that the selective catalytic reactor 128 is provided at a position in the combustion gas exhaust line 130 where the combustion gas temperature passing through the combustion gas exhaust line 130 is approximately equal to the predetermined temperature, or that a temperature regulator (not shown) for regulating the temperature of the catalyst inside the selective catalytic reactor 128 is provided to appropriately regulate the temperature inside the selective catalytic reactor 128. For example, when liquid ammonia in the ammonia storage sealed vessel 12 is used as the reducing agent, a honeycomb body made of a mixed oxide of vanadium, tungsten (or molybdenum), and titanium is preferably used as the catalyst, and the temperature of the catalyst suitable for selective catalytic reduction in this case is approximately 300 to 470° C. As the temperature regulator for maintaining the catalyst temperature in such a temperature range, for example, an electric heater is used.

In order to allow either liquid ammonia or ammonia mixed fuel to flow in a predetermined amount into the combustion gas exhaust line 130 and to use the same as a reducing agent for nitrogen oxides (NOx) in the selective catalytic reactor 128, the combustion device 120 is preferably provided with a nitrogen oxide/ammonia concentration measuring device 122, a supply amount calculating device 124, and a constant amount supplying device 126, as shown in FIG. 15.
The nitrogen oxide/ammonia concentration measuring instrument 122 is provided in the combustion gas exhaust line 130 on the combustion chamber side of the combustor 100 with respect to a junction 130a of the selective catalytic reaction supply line 132 and the combustion gas exhaust line 130, and is configured to measure the nitrogen oxide concentration and the ammonia concentration on the combustion chamber side with respect to the junction 130a. The nitrogen oxide and ammonia concentration measuring instrument 122 can be a known measuring instrument.

The supply amount calculation device 124 is configured to calculate the amount of ammonia or ammonia mixed fuel to be supplied through the selective catalytic reaction supply line 132 based on the measurement results measured by the nitrogen oxide/ammonia concentration measuring device 122. The supply amount calculation device 124 includes, for example, a reference table that predetermines the relationship between the measured concentration and the amount of ammonia or ammonia mixed fuel, and calculates the amount of ammonia or ammonia mixed fuel to be supplied through the selective catalytic reaction supply line 132 by referring to the reference table from the measurement results measured by the nitrogen oxide/ammonia concentration measuring device 122.
The constant-volume feeder 126 is provided in the selective catalytic reaction supply line 132, and is configured to control the amount of ammonia or ammonia mixed fuel supplied based on the amount calculated by the supply amount calculation device 124. The amount of ammonia or ammonia mixed fuel supplied is controlled by adjusting the aperture of an adjustment valve (not shown) provided in the selective catalytic reaction supply line 132, or the liquid supply output of a liquid supply mechanism (not shown) such as a liquid supply pump provided in the constant-volume feeder 126. As a result, even if the concentration of nitrogen oxides or ammonia in the combustion gas fluctuates, the amount of reducing agent can be appropriately adjusted in response to this fluctuation.
The NOx in the combustion gas can be reliably removed by the catalytic reduction using the ammonia supply described above. However, if it is necessary to further check the concentrations of NOx and residual ammonia still remaining in the combustion gas discharged from the selective catalytic reactor 128 and released into the atmosphere, it is preferable to provide another set of nitrogen oxide and ammonia concentration meters (not shown) having the same configuration as the nitrogen oxide and ammonia concentration meters 122 described above in the combustion gas exhaust line 130 downstream of the selective catalytic reactor 128 in addition to the configuration shown in FIG.

The combustor 100 may be an internal combustion engine such as a gas turbine, a jet engine, a reciprocating engine, or a rotary engine, configured to extract mechanical power by utilizing the thermal energy of the combustion gas generated by the combustion of the ammonia mixed fuel. The combustion device 120 may also be equipped with an external combustion engine such as a steam turbine (including a boiler) or a Stirling engine, configured to extract mechanical power by utilizing the thermal energy of the combustion gas generated by the combustion of the ammonia mixed fuel. In this case, the external combustion engine and the combustor 100 may be in close proximity to each other and may be considered to be substantially the same, or may be separate and separated from each other. In the case of a separate and separated body, a combustion gas transfer line (not shown) is provided to connect the combustor 100 and the external combustion engine. A combustion gas exhaust line 130 for the combustion gas used in the external combustion engine and exhausted into the atmosphere is provided at the rear of the external combustion engine.
Furthermore, the combustor 100 may be provided with a heat processing tool (not shown) configured to perform heat processing using the thermal energy of the combustion gas generated by the combustion of the ammonia mixed fuel. The heat processing tool is a tool that performs calcination, roasting, melting, cutting, welding, welding, casting, annealing, bending, heating reduction, incineration, etc. of materials such as metals, ceramics, and resins using the thermal energy of the combustion gas. In this case, the heat processing tool and the combustor 100 may be close to each other and considered to be substantially the same as each other, as in the case of an external combustion engine, or may be separate and separated. In the case of separate and separated, a combustion gas transfer line (not shown) is provided to connect the combustor 100 and the heat processing tool. A combustion gas exhaust line for the combustion gas used in the heat processing tool and exhausted into the atmosphere is provided downstream of the heat processing tool.

(Other applications of ammonia-blended fuel)
Combustion of ammonia-blended fuels can be used in power generation equipment and transport propulsion engines.
The power generation facility is, for example, a power generation facility that generates power in any one of land, water, and air. In this case, the power generation facility is equipped with at least one of the above-mentioned internal combustion engine and the above-mentioned external combustion engine as a combustor 100 for the ammonia-mixed fuel. The generator of the power generation facility is configured to generate power using mechanical power extracted by utilizing thermal energy of the combustion gas of the ammonia-mixed fuel, and the power output end of the power generation facility is configured to output the power generated by the generator. In this case, the power generation facility is provided with a control mechanism configured to control the amount of power at the power output end.

The transportation equipment is equipment configured to move or transport goods in any one of land, water, and airspace, and its propulsion system is a power engine configured to generate thrust for moving the transportation equipment. In this case, the transportation equipment is equipped with at least one of an ammonia-mixed fuel combustion device equipped with an internal combustion engine and an ammonia-mixed fuel combustion device equipped with an external combustion engine as a propulsion system. Furthermore, the transportation equipment is equipped with a power conversion and transmission mechanism configured to utilize mechanical power extracted by at least one of the internal combustion engine and the external combustion engine from the thermal energy of the combustion gas of the ammonia-mixed fuel as at least a part of the thrust of the transportation equipment.
Examples of transport equipment include vehicles (small and large automobiles, motorbikes, etc.) including tank trucks capable of transporting ammonia and ammonia mixed fuel, railroad cars, etc., in land areas, ships in general such as merchant ships, passenger ships, warships, and various work ships including ships for transporting liquefied ammonia, submarines, etc., in water areas, and helicopters, aircraft, airships, drones, etc., in airspace. In this case, the power conversion transmission mechanism is a known series of mechanisms that appropriately change the direction, torque, or speed of the power used for propulsion drive and transmit it to the final drive unit, and includes, for example, cams, cranks, various gears, chains, belts, transmissions, drive shafts, drive wheels, propellers, screws, etc. In addition to the above-mentioned internal combustion engines and external combustion engines, there are other power sources that can supply power, and when these powers are combined to propel and drive a transport equipment, the power conversion transmission mechanism includes, in addition to the series of mechanisms that transmit the power to the drive unit, a synchronization mechanism for both powers and a combined force mechanism such as a coaxial drive.

The transportation equipment may also be equipped with the above-mentioned power generation equipment. In this case, the transportation equipment is preferably equipped with at least one of an electric propulsion mechanism and a power supply mechanism configured to use the thermal energy of the combustion gas of the ammonia mixed fuel to generate electric power output from the power generation equipment for at least a portion of the power required for at least one of propelling the transportation equipment, controlling the operation of the transportation equipment, and maintaining the transportation equipment. In this case, the transportation equipment may be equipped with at least one of an ammonia mixed fuel combustion device equipped with an internal combustion engine and an ammonia mixed fuel combustion device equipped with an external combustion engine. In this case, the transportation equipment is equipped with a power conversion and transmission mechanism configured to convert the mechanical power extracted by at least one of the internal combustion engine and the external combustion engine from the energy of the combustion gas of the ammonia mixed fuel into at least a portion of the power for propelling the transportation equipment.

In this way, ammonia can be efficiently burned using ammonia-mixed fuel, making it suitable for use in internal combustion engines, external combustion engines, heat processing equipment, and power generation facilities that comply with GHG emission regulations.

The above provides a detailed explanation of the ammonia mixed fuel, the ammonia mixed fuel manufacturing apparatus, the ammonia mixed fuel manufacturing method, the ammonia mixed fuel supply apparatus, the ammonia mixed fuel combustion apparatus, the power generation facility using the ammonia mixed fuel, and the transport equipment using the ammonia mixed fuel of the present invention. However, the present invention is not limited to the above-mentioned embodiment and the following examples, and various improvements and modifications may be made without departing from the spirit of the present invention.

Example 1
Using the ammonia mixed fuel production apparatus shown in FIG. 2, liquefied ammonia [NH ₃ ] and liquefied propane [C ₃ H ₈ ] were introduced in this order into a mixing sealed container (capacity: about 2 L) whose temperature was adjusted to about 5° C., with a charge mass ratio of about 75:25 (total mass: about 490 g) (prior to the introduction of these, the inside of the mixing sealed container 16 was first replaced with nitrogen gas, and then with the evaporated vapor of liquefied ammonia, in that order). After the introduction of liquefied ammonia and liquefied propane was completed, all valves were closed, and the mixture was stirred and mixed with a single-type stirring blade stirrer while adjusting the liquid phase temperature to about 20° C., and the liquid phase soon separated into two phases, an upper layer mainly made of propane and a lower layer mainly made of ammonia, and stabilized. At this time, the volume ratio of the upper layer to the lower layer was about 15:85 (total volume: about 810 cm ³ ), and the internal pressure (saturated vapor pressure) was about 1.6 MPa. At this time, while maintaining the airtightness, a capillary (not shown) was inserted into the upper layer and the lower layer using the gas phase discharge line 21, and about 0.5 ^cm3 of a sample was taken from each of the upper layer and the lower layer. The ammonia concentrations in the upper layer and the lower layer were measured by gas chromatography, and were found to be about 16 mass% and about 87 mass%, respectively (the average liquid phase ammonia concentration of the entire upper and lower layers was about 77 mass%).
Thereafter, when the liquid phase temperature was increased while continuing stirring, the two-liquid phase interface between the upper and lower layers rose, and the upper layer disappeared at about 23°C, and an ammonia-mixed fuel in which the entire mixture was uniformly dissolved was obtained. At this time, the internal pressure (saturated vapor pressure) of the mixing sealed container was about 1.7 MPa. Even if the liquid phase temperature was increased beyond this temperature, the liquid phase remained uniform, but when the liquid phase temperature was subsequently lowered to less than about 23°C, it separated into two phases again. Furthermore, even after maintaining the liquid phase temperature at about 23°C for about one day, the liquid phase did not separate, and the internal pressure was maintained at about 1.7 MPa.

Example 2
Using the same mixed fuel production apparatus as in Example 1, liquefied ammonia and liquefied n-butane [n-C ₄ H ₁₀ ] were introduced into a mixing sealed vessel (capacity: about 2 L) whose temperature was adjusted to about 5° C., starting with liquefied n-butane, at a charge mass ratio of about 85:15 (total mass: about 570 g). Prior to the introduction of these, the inside of the mixing sealed vessel 16 was first replaced with nitrogen gas, and then with the vaporized vapor of liquefied n-butane, in that order. After the introduction of liquefied ammonia and liquefied n-butane was completed, all valves were closed, and the mixture was stirred and mixed with a stirrer having a single stirring blade while adjusting the liquid phase temperature to about 20° C., and the liquid phase soon separated into two phases, an upper layer mainly composed of n-butane and a lower layer mainly composed of ammonia, and stabilized. At this time, the volume ratio of the upper layer to the lower layer was about 7:93 (total volume: about 940 cm ³ ), and the internal pressure (saturated vapor pressure) was about 1.0 MPa.
After that, when the liquid phase temperature was increased while continuing stirring, the two-liquid phase interface between the upper and lower layers rose, and the upper layer disappeared at about 32°C, and an ammonia-mixed fuel in which the entire mixture was uniformly dissolved was obtained. At this time, the internal pressure (saturated vapor pressure) of the mixing sealed container was about 1.4 MPa. Even if the liquid phase temperature was increased beyond this temperature, the liquid phase remained uniform, but when the liquid phase temperature was then lowered to less than about 32°C, it separated into two phases again. Furthermore, even after the liquid phase temperature was maintained at about 32°C for about 10 hours, the liquid phase did not separate, and the internal pressure was maintained at about 1.4 MPa.

Example 3
Using the same ammonia blended fuel production apparatus as in Example 1, first, a mixed surfactant was introduced into a mixing sealed vessel in a molar ratio of approximately 80:20 consisting of a long-chain alkylamine [rational formula: C _k H _{2k+1 NH 2} , k≒8-18], which is a non-ionic primary amine having one long-chain alkyl group derived from coconut oil and a primary amino group [—NH 2 ] in the molecule, and an ionic quaternary ammonium chloride [rational formula: C ₁₂ H 25 N + (CH 3 ) 3.Cl − ] having one long-chain alkyl chain with 12 carbon atoms in the molecule and a quaternary trimethylammonium group which is a chloride (rational formula: C 12 H ₂₅ N ⁺ (CH ₃ ) _3.Cl ⁻ ), so that the concentration in the ammonia blended fuel produced was 1 mass % (amount introduced: 5.76 g). Thereafter, in the same manner as in Example 2, liquefied n-butane and liquefied ammonia were introduced into a mixing sealed vessel (capacity: about 2 L) whose temperature was adjusted to about 5° C., at a charge mass ratio of about 85:15 (total mass: about 570 g). Advance gas replacement was also carried out in the same manner as in Example 2.
After the introduction was completed, the liquid phase temperature was adjusted to about 20° C., and the mixture was stirred and mixed for about 30 minutes with a stirrer equipped with a single stirring blade. The mixture was separated into two phases, an upper layer mainly made of n-butane and a lower layer mainly made of ammonia, and stabilized. However, the volume of the upper layer mainly made of n-butane was reduced compared to that in Example 2, and the entire liquid phase became slightly turbid and had formed an emulsion.
Thereafter, when the liquid phase temperature was increased while continuing stirring, the upper layer disappeared at about 26°C, which was about 6°C lower than in Example 2, and a uniformly emulsified ammonia-mixed fuel was obtained. At this time, the internal pressure (saturated vapor pressure) of the mixing sealed vessel was about 1.1 MPa, which was about 0.3 MPa lower than in Example 2. Even when the liquid phase temperature was increased beyond this point, the liquid phase maintained a uniform emulsion state, but when the liquid phase temperature was subsequently decreased to below about 26°C, the liquid phase separated again into two phases.
Even after this emulsified ammonia mixed fuel was kept at about 26° C. for about 10 hours, the liquid phase did not separate and the internal pressure was maintained at about 1.1 MPa.

(Reference example 1)
In the above Example 3, the blending ratio of the nonionic long-chain alkylamine and the ionic quaternary ammonium chloride was changed to 0:100 (i.e., ionic only), 20:80, 50:50, 65:35, 90:10, and 100:0 (i.e., nonionic only), and each was introduced so that the concentration in the produced ammonia mixed fuel was 1 mass% (introducing amount 5.76 g). For each case, stirring and mixing were performed under the same conditions as in Example 3, and the temperature at which the entire mixture was homogenized was examined in the same manner as in Example 3. When the blending ratio was 0:100, 20:80, 50:50, 65:35, and 100:0, the homogenization temperature was about 32°C, the same as in Example 2 where no surfactant was added, and the effect of emulsification due to the addition of a surfactant was hardly observed. However, when the blending ratio was 0:100, 20:80, 50:50, and 65:35, the interface between the upper and lower layers was curved in a convex shape downward, and a significant change in the interfacial tension between the upper and lower layers was observed due to the presence of nonionic alkylamine at the interface. In addition, when the blending ratio was 90:10, the homogenization temperature was about 30°C, which was slightly higher than about 26°C when the blending ratio was 80:20 in Example 3, and although emulsification was observed, it was determined that the emulsion forming ability was lower.

Example 4
A mixed surfactant having the same components and the same mixing ratio as those used in Example 3 was introduced into a mixing sealed vessel (amount introduced: 30 g) so that the concentration in the produced ammonia mixed fuel was 5 mass %, and stirring and mixing was performed at about 20° C. under the same conditions as in Example 3, except that the stirring and mixing time was extended to about 2 hours.
Thereafter, when the liquid phase temperature was increased while continuing stirring, the upper layer disappeared at about 21°C, which was about 11°C lower than in Example 2, and a uniformly emulsified ammonia-mixed fuel was obtained. At this time, the internal pressure (saturated vapor pressure) of the mixing sealed vessel became about 1.0 MPa, which was about 0.4 MPa lower than in Example 2.
Even after this emulsified ammonia mixed fuel was kept at about 21° C. for about 10 hours, the liquid phase did not separate and the internal pressure was maintained at about 1.0 MPa.

Example 5
A non-ionic long-chain alkylamine [rational formula: C ₈ H 17 NH 2 ] having one long-chain alkyl group with 8 carbon atoms and a primary amino group [-NH ₂ ] in the molecule was used, which has a different alkyl chain length from that in Example _{3. A mixed surfactant containing this and an ionic quaternary ammonium chloride [rational formula: C 12 H 25} N ⁺ (CH ₃ ) ₃ ·Cl ^- ] in the same manner as in Example 3 in a molar ratio of approximately 80:20 was introduced (amount introduced: 5.76 g) so that the concentration in the produced ammonia mixed fuel was 1 mass %. Stirring and mixing were performed at approximately 20°C under the same conditions as in Example 3.
Thereafter, when the liquid phase temperature was increased while continuing stirring, the upper layer disappeared at about 27°C, which was about 5°C lower than in Example 2, and a uniformly emulsified ammonia-mixed fuel was obtained. At this time, the internal pressure (saturated vapor pressure) of the mixing sealed vessel became about 1.1 MPa, which was about 0.3 MPa lower than in Example 2.
Even after this emulsified ammonia mixed fuel was kept at about 27° C. for about 10 hours, the liquid phase did not separate and the internal pressure was maintained at about 1.1 MPa.

Example 6
The mixture was stirred and mixed at about 20°C under the same conditions as in Example 3, except that a mixed surfactant containing a long-chain alkylamine, which is a non-ionic primary amine having 8 to 18 carbon atoms [rational formula: C _k H _2k+1 NH ₂ , k≈8 to 18], which is a carbon number of 8 to 18, and an ionic quaternary ammonium bromide, which has one long-chain alkyl group with 12 carbon atoms in the molecule and a quaternary trimethylammonium bromide group [rational formula: C ₁₂ H ₂₅ N ⁺ (CH ₃ ) _3.Br ⁻ ], in a molar ratio of about 80:20, was introduced so that the concentration in the ammonia mixed fuel produced was 1 mass% (introduced amount 5.76 g).
Thereafter, when the liquid phase temperature was increased while continuing stirring, the upper layer disappeared at about 30°C, which was about 2°C lower than in Example 2, and a uniformly emulsified ammonia-mixed fuel was obtained. At this time, the internal pressure (saturated vapor pressure) of the mixing sealed vessel became about 1.2 MPa, which was about 0.2 MPa lower than in Example 2.
Even after this emulsified ammonia mixed fuel was kept at about 30° C. for about 10 hours, the liquid phase did not separate and the internal pressure was maintained at about 1.2 MPa.

(Example 7)
_A mixed surfactant containing a nonionic long-chain alkyldiethanolamide [rational formula: CkH2k+1C(=O)N( _C2H4OH ) ₂ ] (k is an integer from 8 to 18) having one long-chain alkyl group with 8 to 18 carbon atoms derived from coconut oil and a tertiary diethanolamide group [-C(=O) _{N ( C2H4OH} ) ₂ ] in ^{the molecule, and an ionic quaternary ammonium chloride (rational formula: C12H25N+} _{( CH3 ) 3.Cl- )} common to Example 3, in a molar ratio of about 80:20, was introduced so that the concentration in the produced ammonia mixed fuel was 1 ^mass % (amount introduced: 5.76 g). Stirring and mixing were performed at about 20°C under the same conditions as in Example 3.
Thereafter, when the liquid phase temperature was increased while continuing stirring, the upper layer disappeared at about 30°C, which was about 2°C lower than in Example 2, and a uniformly emulsified ammonia-mixed fuel was obtained. At this time, the internal pressure (saturated vapor pressure) of the mixing sealed vessel became about 1.3 MPa, which was about 0.1 MPa lower than in Example 2.
Even after this emulsified ammonia mixed fuel was kept at about 30° C. for about 10 hours, the liquid phase did not separate and the internal pressure was maintained at about 1.3 MPa.

(Example 8)
Stirring and mixing was performed at approximately 20° _C under the same conditions as in Example 3 _, except that a mixed surfactant containing a nonionic _{polyoxyethylene} alkyl ether [rational formula: _C13H27O ( _C2H4O ) ₅ -H] having one long-chain alkyl group with 13 ^carbon atoms and a polyoxyethylene group [-O( _C2H4O ) ₅ -H] in the molecule and an ionic _quaternary ammonium chloride (rational formula: _C12H25N ⁺ ( _CH3 ) _3.Cl- ) common to Example 3 in a molar ratio of approximately 80:20 was introduced (amount introduced: 5.76 g) so that the concentration in the produced ammonia mixed fuel was 1 mass%.
Thereafter, when the liquid phase temperature was increased while continuing stirring, the upper layer disappeared at about 29°C, which was about 3°C lower than in Example 2, and a uniformly emulsified ammonia-mixed fuel was obtained. At this time, the internal pressure (saturated vapor pressure) of the mixing sealed vessel became about 1.2 MPa, which was about 0.2 MPa lower than in Example 2.
Even after this emulsified ammonia mixed fuel was kept at about 29° C. for about 10 hours, the liquid phase did not separate and the internal pressure was maintained at about 1.2 MPa.

Example 9
A nonionic long-chain tertiary amine [rational formula _: CsH2s+1N+(( _C2H4O ) _d -H)(( _C2H4O ) _e -H)] (s is an integer of 8 to 18, d and _e are positive integers such that d+e=5) having one long-chain alkyl group with 8 to 18 carbon atoms derived from _{coconut oil in the molecule and a tertiary polyoxyethylene amino group [-N((C2H4O)d-H)((C2H4O ) e - H )} ^{] (} _{d and} e are positive integers such that d+e=5) and an ionic _quaternary ammonium chloride (rational formula: _C12H25N ⁺ ( _CH3 ) _3.Cl- The mixture was stirred and mixed at about 20° C. under the same conditions as in Example 3, except that a mixed surfactant containing 5.76 g of ...
Thereafter, when the liquid phase temperature was increased while continuing stirring, the upper layer disappeared at about 29°C, which was about 3°C lower than in Example 2, and a uniformly emulsified ammonia-mixed fuel was obtained. At this time, the internal pressure (saturated vapor pressure) of the mixing sealed vessel became about 1.2 MPa, which was about 0.2 MPa lower than in Example 2.
Even after this emulsified ammonia mixed fuel was kept at about 29° C. for about 10 hours, the liquid phase did not separate and the internal pressure was maintained at about 1.2 MPa.

(Example 10)
Stirring and mixing was performed under the same conditions as in Example 3 at about 20°C, except that a mixed surfactant containing a nonionic long-chain primary amine having 8 carbon atoms (rational formula: C ₈ H ₁₇ NH ₂ ) and an ionic long-chain carboxylic acid having one long-chain alkyl group having 10 to 18 carbon atoms derived from coconut oil and a carboxyl group [-C(=O)OH] in a molar ratio of about 80:20 (rational formula: C _k H _2k+1 C(=O)OH, k is an integer from 10 to 18) was introduced so that the concentration in the produced ammonia mixed fuel was 1 mass% (introduced amount 5.76 g).
Thereafter, when the liquid phase temperature was increased while continuing stirring, the upper layer disappeared at about 29°C, which was about 3°C lower than in Example 2, and a uniformly emulsified ammonia-mixed fuel was obtained. At this time, the internal pressure (saturated vapor pressure) of the mixing sealed vessel became about 1.2 MPa, which was about 0.2 MPa lower than in Example 2.
Even after this emulsified ammonia mixed fuel was kept at about 29° C. for about 10 hours, the liquid phase did not separate and the internal pressure was maintained at about 1.2 MPa.

Example 11
A mixed surfactant containing a nonionic long-chain tertiary amine having a tertiary polyoxyethylene amino group [rational formula: _{CsH2s +} 1N ⁺ (( _C2H4O ) _d -H)(( _C2H4O ) _e -H)] (d and e are positive integers such that d+e=5) common to Example 9 and an ionic long-chain carboxylic acid having 10 to 18 carbon atoms [rational formula: _{CkH2k +1C (} =O)OH, k≈10-18] common to Example 10 in a molar ratio of about 80:20 was introduced so that the concentration in the produced ammonia mixed fuel was 1 mass% (introduced amount 5.76 g) _. Except for this, stirring and mixing were performed at about 20°C under the same conditions as in Example 3.
Thereafter, when the liquid phase temperature was increased while continuing stirring, the upper layer disappeared at about 28°C, which was about 4°C lower than in Example 2, and a uniformly emulsified ammonia-mixed fuel was obtained. At this time, the internal pressure (saturated vapor pressure) of the mixing sealed vessel became about 1.2 MPa, which was about 0.2 MPa lower than in Example 2.
Even after this emulsified ammonia mixed fuel was kept at about 27° C. for about 10 hours, the liquid phase did not separate and the internal pressure was maintained at about 1.2 MPa.

(Reference example 2)
In the above Example 11, the mixing ratio of the nonionic long-chain tertiary amine having a tertiary bis(polyethoxy)amino group and the ionic long-chain carboxylic acid was changed to 0:100 (i.e., ionic only) and 20:80, respectively, and each was introduced so that the concentration in the produced ammonia mixed fuel was 1 mass% (introduced amount 5.76 g). In each case, the temperature at which the whole was homogenized was examined as in Example 3. In both cases of the mixing ratio of 0:100 and 20:80, the homogenization temperature was about 32 to 33°C, which was the same as or slightly higher than that of Example 2 in which no surfactant was added, and the effect of emulsification by adding a surfactant was hardly observed.

Example 12
A mixed surfactant having the same components and the same mixing ratio as those used in Example 11 was introduced into a mixing sealed vessel (amount introduced: 30 g) so that the concentration in the produced ammonia mixed fuel was 5 mass %, and stirring and mixing was performed at about 20°C under the same conditions as in Example 3, except that the stirring and mixing time was extended to about 2 hours.
Thereafter, when the liquid phase temperature was increased while continuing stirring, the upper layer disappeared at about 23°C, which was about 9°C lower than in Example 2, and a uniformly emulsified ammonia-mixed fuel was obtained. At this time, the internal pressure (saturated vapor pressure) of the mixing sealed vessel became about 1.1 MPa, which was about 0.3 MPa lower than in Example 2.
Even after this emulsified ammonia mixed fuel was kept at about 23° C. for about 10 hours, the liquid phase did not separate and the internal pressure was maintained at about 1.1 MPa.

Example 13
Using the ammonia mixed fuel production apparatus shown in FIG. 2, liquefied ammonia and methanol (CH ₃ OH) were introduced into a mixing sealed container (capacity: about 2 L) whose temperature was adjusted to about 15° C., starting with methanol, at a charge mass ratio of about 70:30 (total mass: about 660 g). Prior to these introductions, the inside of the mixing sealed container 16 was first replaced with nitrogen gas, and then with the vaporized vapor of liquefied ammonia, in that order. After these introductions were completed, all valves were closed, and the mixture was stirred and mixed with a single-type stirring blade stirrer while adjusting the liquid phase temperature to about 19° C., and the liquid phase soon became a uniform solution. At this time, the internal pressure (saturated vapor pressure) was about 0.7 MPa, which was about 0.1 MPa lower than the saturated vapor pressure of pure ammonia at the same temperature, which was about 0.8 MPa.
Thereafter, even when the liquidus temperature was increased to about 40° C. while continuing stirring, the liquid phase remained in a homogeneous solution state. Moreover, even after the liquidus temperature was maintained at about 19° C. for about one day, the liquid phase remained in a compatible state, and the internal pressure was maintained at about 0.7 MPa.
In addition, in the above-mentioned Example 13, the mass ratio of the liquefied ammonia and methanol was changed to about 50:50 (total mass about 710 g) and about 30:70 (total mass about 710 g), respectively, and the mixing state was examined in the same manner as in Example 13 when stirring and mixing were performed under the same conditions. In either case of the feed composition ratio of about 50:50 and about 30:70, the liquid phase became a uniform solution, and the internal pressure (saturated vapor pressure) at a liquid phase temperature of about 19°C was about 0.5 MPa and about 0.3 MPa, respectively. In either case of these feed composition ratios, even after holding the liquid phase temperature at about 19°C for about one day, the liquid phase was maintained in a compatible state, and the internal pressure was also maintained at about 0.5 MPa and about 0.3 MPa, respectively.

(Example 14)
Using the ammonia-mixed fuel production apparatus shown in FIG. 2, liquefied ammonia and regular gasoline available in Japan (note: the specific gravity of regular gasoline is about 0.74 g/cm ³ , which is greater than the specific gravity of liquefied ammonia) were introduced into a mixing sealed container (contents about 2 L) whose temperature was adjusted to about 15° C., starting with regular gasoline, at a charge mass ratio of liquefied ammonia:regular gasoline=about 40:60 (total mass about 670 g). Prior to these introductions, the inside of the mixing sealed container 16 was first replaced with nitrogen gas, and then with the vaporized vapor of liquefied ammonia, in that order. After these introductions were completed, all valves were closed, and the mixture was stirred and mixed with a stirrer with a single-type stirring blade while adjusting the liquid phase temperature to about 46° C., and the liquid phase soon became a uniform solution. At this time, the internal pressure (saturated vapor pressure) was about 1.7 to 1.8 MPa, which is approximately equal to the saturated vapor pressure of pure ammonia at the same temperature.
Thereafter, even if the liquidus temperature was further increased while stirring was continued, the liquid phase remained in a homogeneous solution state. On the other hand, when the liquidus temperature was lowered to about 44°C while stirring was continued, a different phase began to be liberated and floated in the solution, and at about 43°C, a new liquid phase (liquefied ammonia) that had phase-separated clearly appeared on the upper side of the layer of the above-mentioned solution (the internal pressure at this time was about 1.5 MPa). Furthermore, even after maintaining the liquidus temperature at about 46°C for about one day, the liquid phases remained in a compatible state, and the internal pressure was also maintained at about 1.7 to 1.8 MPa.

10 Manufacturing apparatus 12 Ammonia storage sealed container 14, 14 ₁ , 14 ₂ Combustion improver storage sealed container 16 Mixing sealed container 17 Temperature control jacket 17a Temperature control medium inlet nozzle 17b Temperature control medium outlet nozzle 18 Ammonia introduction line 18a, 20a, 20a ₁ , 20a ₂ , 28a Flow meter 18b, 20b, 28b, 18c, 19c, 20b 1, 20c ₁ , 20b ₂ , 20c ₂ , 20c, _22a , 28c Adjustment valve 18d, 20d ₁ Cooling device 19d, 20d, 20d ₂ , 28d Liquid transfer pump 20, 20 ₁ , 20 ₂ Combustion improver introduction line 21 Gas phase discharge line 21a Gas phase discharge valve 22, 22 ₁ , 22 _2. Liquid phase discharge lines 22a, 22a ₁ , 22a _2. Liquid phase discharge valves 22b, 22b ₁ , 22b _2. Discharge flow meters 22c, 22c ₁ , 22c _2. Composition evaluation means 24, 63 3. Agitator 26 4. Surfactant storage container 28 5. Surfactant introduction line 30 6. Nitrogen gas introduction mechanism 30a 7. Nitrogen gas introduction valve 30b 8. Nitrogen gas introduction line 30c 9. Nitrogen gas pressure gauge 30d 10. Nitrogen gas pressure reducing valve 30e 11. Nitrogen gas adjustment valve 31 12. Pressure gauge 32 13. Control device 33 14. Thermometer 50 15. Storage airtight container 52 16. Inlet 54 17. Discharge port 56 18. Connection mechanism 58 19. Discharge valve 59 20. Gas phase discharge line 59a 21. Gas phase discharge valve 60 22. Ammonia mixed fuel supply line 61 23. Thermometer 62 24. Pressure gauge 63 25. Agitator 64 26. Nitrogen gas injection line 64a 27. Pressure reducing valve 64b 28. Pressure gauge 64c 29. Adjustment valve 65 30. Volumetric flow meter 66 31. Cylinder 67 Piston 68, reciprocating drive device 68a, motor 68b, crank mechanism 69, mixed state evaluation device 70, supply device 80, supply machine 100, combustor 110, branching section 112, ammonia mixed fuel reflux line 120, combustion device 122, nitrogen oxide/ammonia concentration measuring device 124, supply amount calculation device 126, fixed amount supply device 128, selective catalytic reactor 130, combustion gas exhaust line

Claims (59)

An ammonia-blended fuel,
Liquefied ammonia;
A combustion improver that assists the combustion of the ammonia,
The combustion improver is
(a) liquefied petroleum gas, naphtha, gasoline, kerosene, and diesel; and (b) a feedstock hydrocarbon which is at least one hydrocarbon species contained as a component in any one of the liquefied petroleum gas, the naphtha, the gasoline, the kerosene, and the diesel.
At least one of
The content of the ammonia is 20 to 99 mass %,
The ammonia mixed fuel is in a gas-liquid equilibrium state, and is maintained at a predetermined temperature according to a liquid phase composition such that an entire liquid phase portion of the ammonia mixed fuel is in a solution state in which the ammonia and the combustion improver are dissolved in each other, or in an emulsion state of the ammonia and the combustion improver. The ammonia mixed fuel according to claim 1, wherein the ammonia mixed fuel is isolated and stored in a sealed environment in which gas-liquid equilibrium is maintained. An ammonia-blended fuel,
Liquefied ammonia;
A combustion improver that assists the combustion of the ammonia,
The combustion improver is
(a) Liquefied petroleum gas, naphtha, gasoline, kerosene, and diesel;
(b) a feedstock hydrocarbon which is at least one hydrocarbon species contained as a component in any one of the liquefied petroleum gas, the naphtha, the gasoline, the kerosene, and the diesel; and (c) a feedstock alcohol which is an alcohol having 3 or less carbon atoms.
At least one of
The ammonia mixed fuel is in a gas-liquid equilibrium state, and at least a part of a liquid phase portion of the ammonia mixed fuel is in a solution state in which the ammonia and the combustion improver are dissolved in each other, or in an emulsion state of the ammonia and the combustion improver,
The ammonia-mixed fuel further contains 0.1 to 10 mass % of a surfactant. 4. The ammonia-mixed fuel of claim 3 , wherein the surfactant comprises at least one non-ionic surfactant and at least one ionic surfactant. The surfactant is
(A) In the molecular structure, a primary or secondary amino group [-NH ₂ or >NH], a polyoxyalkylene amino group [>N(C _a H _2a O) _c -H or -N((C _b H _2b O) _d -H) ((C _b H _2b O) _e -H)] (a and b are 2 or 3, c is an integer of 1 to 8, d and e are 0 or positive integers such that d+e=1 to 8), an amide group [-C(=O)NH ₂ ], a polyoxyalkylene amide group [-C(=O)N((C _f H _2f O) _g -H) ((C _f H _2f O) _h -H)] (f is 2 or 3, g and h are 0 or positive integers such that g+h=1 to 8), and a polyoxyalkylene group [-O(C _i H _2i O) _j -H] (i is 2 or 3, j is an integer of 1 to 8),
and at least one of the nonionic surfactants having at least one alkyl group [C _k H _2k+ 1 -] (k is an integer of 7 to 18) and an alkenyl group [C _l H _2l-1 -] (l is an integer of 7 to 18) as a nonpolar moiety;
(B) in its molecular structure, it has at least one of the following ionic polar sites: a quaternary methylammonium group, a quaternary methylalkanolammonium group, or a quaternary alkanolammonium group [-N ⁺ (CH ₃ ) _p (C _m H _2m OH) _q.X ^- , or >N ⁺ (CH ₃ ) _r (C _n H _2n OH) _s.X ' ^- ] (m and n are 2 or 3, p and q are 0 or positive integers such that p + q = 3, r and s are 0 or positive integers such that r + s = 2, and X and X' are any of Cl, Br, and I), and a carboxyl group [-C(=O)OH];
and at least one of the ionic surfactants having at least one alkyl group [C _t H _2t+1 -] (where t is an integer from 7 to 18) and at least one alkenyl group [C _u H _2u-1 -] (where u is an integer from 7 to 18) as a non-polar moiety. A manufacturing apparatus for manufacturing an ammonia mixed fuel,
a sealed ammonia storage container for storing liquefied ammonia;
(a) a sealed container for storing a combustion improver that assists the combustion of the ammonia, the combustion improver being at least one of: (a) liquefied petroleum gas, naphtha, gasoline, kerosene, and diesel; (b) a raw material hydrocarbon that is at least one hydrocarbon species contained as a component in any one of the liquefied petroleum gas, the naphtha, the gasoline, the kerosene, and the diesel; and (c) a raw material alcohol that is an alcohol having 3 or less carbon atoms;
a mixing sealed container configured to obtain a dissolved solution state or an emulsified mixture by stirring and mixing the ammonia and the combustion improver with a stirrer, and to enable the mixture obtained by stirring and mixing with the stirrer to maintain a gas-liquid equilibrium state;
an ammonia introduction line provided with an ammonia quantitative introduction mechanism configured to connect the ammonia storage sealed container and the mixing sealed container and introduce a predetermined amount of the ammonia into the mixing sealed container;
a combustion improver introduction line that connects the combustion improver storage sealed container and the mixing sealed container and is provided with a combustion improver quantitative introduction mechanism configured to introduce a predetermined amount of the combustion improver from the combustion improver storage sealed container into the mixing sealed container;
and at least one liquid phase discharge line configured to discharge the mixture obtained by stirring and mixing of the agitator in the sealed mixing container as an ammonia mixed fuel from the sealed mixing container. 7. The apparatus for producing an ammonia mixed fuel according to claim 6, further comprising a temperature control mechanism configured to control a temperature of the mixture so that a saturated vapor pressure of the mixture in the mixing sealed container is within a temperature range not exceeding a set pressure resistance of the mixing sealed container when the ammonia and the combustion improver are introduced into the mixing sealed container and stirred and mixed by the stirrer . 8. The apparatus for producing an ammonia-mixed fuel according to claim 7, wherein the temperature control mechanism is configured to control a temperature of the mixture so that, when the ammonia and the combustion improver are introduced into the sealed mixing container and stirred and mixed by the stirrer, the mixture maintains a gas-liquid equilibrium state in the sealed mixing container, and the entire liquid phase portion of the mixture is in a temperature range such that the ammonia and the combustion improver are in a solution state in which they are dissolved in each other, or in an emulsion state of the ammonia and the combustion improver, depending on a liquid phase composition of the mixture. The ammonia mixed fuel contains, as the combustion improver, at least one of the liquefied petroleum gas, the feedstock hydrocarbon, and the feedstock alcohol,
The feedstock hydrocarbon is at least one hydrocarbon species contained as a component in the liquefied petroleum gas,
The raw material alcohol is methanol,
9. The apparatus for producing an ammonia mixed fuel according to claim 6 , wherein the combustion improver storage sealed container stores at least one of the liquefied petroleum gas, the feedstock hydrocarbon, and the feedstock alcohol. 10. The apparatus for producing an ammonia mixed fuel according to claim 6 , further comprising a nitrogen gas introduction line connected to the mixing sealed container, configured to introduce nitrogen gas into a gas phase portion in the mixing sealed container at a discharge pressure equal to or higher than a saturated vapor pressure of the mixture in the mixing sealed container when the ammonia mixed fuel is discharged from the liquid phase discharge line. The liquid phase discharge line is provided with a discharge flow meter configured to continuously measure a discharge flow rate of the ammonia mixed fuel discharged through the liquid phase discharge line;
10. The apparatus for producing an ammonia mixed fuel according to claim 6 , wherein the ammonia quantitative introduction mechanism and the combustion improver quantitative introduction mechanism are configured so that the ammonia can be continuously introduced into the mixing sealed container at a flow rate equal to a discharge flow rate of the ammonia discharged through the liquid phase discharge line, which is calculated from the discharge flow rate of the ammonia mixed fuel measured by the discharge flow meter and a liquid phase composition of the ammonia mixed fuel, and in parallel, the combustion improver can be continuously introduced into the mixing sealed container at a flow rate equal to a discharge flow rate of the combustion improver discharged through the liquid phase discharge line, which is calculated from the discharge flow rate of the ammonia mixed fuel measured by the discharge flow meter and a liquid phase composition of the ammonia mixed fuel. Further, a surfactant storage container for storing a surfactant;
a surfactant introduction line that connects the surfactant storage container and the sealed mixing container and is provided with a surfactant quantitative introduction mechanism configured to introduce a predetermined amount of the surfactant into the sealed mixing container;
The apparatus for producing an ammonia-mixed fuel according to any one of claims 6 to 10, wherein in the sealed mixing container, the surfactant is stirred and mixed with the ammonia and the combustion improver by the stirrer, and the mixture containing the surfactant is discharged through the liquid phase discharge line. The ammonia quantitative introduction mechanism and the combustion improver quantitative introduction mechanism are the ammonia quantitative introduction mechanism and the combustion improver quantitative introduction mechanism according to claim 11 ,
12. The exhaust flow meter of claim 11 ,
13. The apparatus for producing an ammonia-mixed fuel according to claim 12, wherein the surfactant quantitative introduction mechanism is configured to be able to continuously introduce a quantitative amount of the surfactant from the surfactant storage container into the mixing closed container at a flow rate equal to a discharge flow rate of the surfactant discharged through the liquid phase discharge line, the discharge flow rate of the ammonia-mixed fuel being calculated by multiplying a concentration of the surfactant in the ammonia-mixed fuel calculated from the amounts of the ammonia, the combustion improver, and the surfactant previously introduced into the mixing closed container by the discharge flow rate of the ammonia-mixed fuel measured by the discharge flow meter . 14. The apparatus for producing an ammonia-mixed fuel according to claim 12 or 13 , wherein the surfactant comprises at least one non-ionic surfactant and at least one ionic surfactant. The surfactant is
(A) In the molecular structure, a primary or secondary amino group [-NH ₂ or >NH], a polyoxyalkylene amino group [>N(C _a H _2a O) _c -H or -N((C _b H _2b O) _d -H) ((C _b H _2b O) _e -H)] (a and b are 2 or 3, c is an integer of 1 to 8, d and e are 0 or positive integers such that d+e=1 to 8), an amide group [-C(=O)NH ₂ ], a polyoxyalkylene amide group [-C(=O)N((C _f H _2f O) _g -H) ((C _f H _2f O) _h -H)] (f is 2 or 3, g and h are 0 or positive integers such that g+h=1 to 8), and a polyoxyalkylene group [-O(C _i H _2i O) _j -H] (i is 2 or 3, j is an integer of 1 to 8),
and at least one of the nonionic surfactants having at least one alkyl group [C _k H _2k+ 1 -] (k is an integer of 7 to 18) and an alkenyl group [C _l H _2l-1 -] (l is an integer of 7 to 18) as a nonpolar moiety;
(B) in its molecular structure, it has at least one of the following ionic polar sites: a quaternary methylammonium group, a quaternary methylalkanolammonium group, or a quaternary alkanolammonium group [-N ⁺ (CH ₃ ) _p (C _m H _2m OH) _q.X ^- , or >N ⁺ (CH ₃ ) _r (C _n H _2n OH) _s.X ' ^- ] (m and n are 2 or 3, p and q are 0 or positive integers such that p + q = 3, r and s are 0 or positive integers such that r + s = 2, and X and X' are any of Cl, Br, and I), and a carboxyl group [-C(=O)OH];
and at least one of the ionic surfactants having at least one alkyl group [C _t H _2t+1 -] (t is an integer of 7 to 18) and at least one alkenyl group [C _u H _2u-1 -] (u is an integer of 7 to 18) as a non-polar moiety. The combustion improver is at least one of those described in (a) and (b),
the ammonia quantitative introduction mechanism and the combustion improver quantitative introduction mechanism are configured to introduce the ammonia and the combustion improver into the mixing sealed container at a predetermined ratio so that when the ammonia and the combustion improver are stirred and mixed in the mixing sealed container, a liquid phase portion of the mixture separates into upper and lower two layers, and each of the upper and lower two separated liquid phase portions is entirely in a solution state or an emulsion state, and the temperature adjustment mechanism is configured to perform the stirring and mixing while maintaining a predetermined liquid phase temperature,
8. The apparatus for producing an ammonia mixed fuel according to claim 6 or 7, wherein the liquid phase portion of at least one of the upper and lower two layers is discharged from the mixing sealed container through one or two of the liquid phase discharge lines, thereby producing one or two ammonia mixed fuels in which the ammonia and the combustion improver are in a solution state or an emulsion state at one or two predetermined composition ratios. The mixing sealed container is provided with a mixing state evaluation device configured to evaluate the mixing state of the mixture,
The apparatus for producing an ammonia-mixed fuel according to any one of claims 6 to 16 , further comprising an agitation adjustment device that adjusts the strength and time of the agitation and mixing by the agitator according to the evaluation result of the mixed state evaluation device. The apparatus for producing an ammonia mixed fuel according to any one of claims 6 to 17, wherein a temperature control device configured to control a temperature of the ammonia and a temperature of the combustion improver so that a temperature of the ammonia passing through the ammonia introduction line and a temperature of the combustion improver passing through the combustion improver introduction line become equal to a temperature of the mixture inside the mixing sealed container when the ammonia and the combustion improver are introduced into the mixing sealed container is provided in the ammonia introduction line and the combustion improver introduction line , respectively. The apparatus for producing an ammonia mixed fuel according to any one of claims 6 to 18, wherein a heating device is provided in the ammonia storage sealed container and/or the combustion improver storage sealed container, the heating device heating the ammonia in the ammonia storage sealed container and/or the combustion improver in the combustion improver storage sealed container when the ammonia and the combustion improver are introduced into the mixing sealed container. Further comprising a sealed container for storing the ammonia mixed fuel configured to store the ammonia mixed fuel in a gas-liquid equilibrium state;
The sealed storage container includes an inlet through which the ammonia mixed fuel is injected, and an outlet provided at a lower portion of the sealed storage container and configured to discharge the ammonia mixed fuel to the outside,
The device for producing ammonia mixed fuel according to any one of claims 6 to 19 , wherein the injection port is provided with a connection mechanism configured to inject the ammonia mixed fuel from the liquid phase discharge line into the sealed storage container while maintaining airtightness and internal pressure. The apparatus for producing an ammonia mixed fuel according to claim 20 , wherein the storage sealed container is provided with an agitator configured to agitate and mix the ammonia mixed fuel. The storage sealed container is provided with a mixture state evaluation device configured to evaluate a mixture state of the ammonia mixed fuel,
The apparatus for producing an ammonia-mixed fuel according to claim 21, further comprising an agitation adjustment device that adjusts the strength and time of the agitation by the agitator provided in the sealed storage container based on the evaluation result of the mixed state obtained by the mixed state evaluation device. 23. The apparatus for producing ammonia mixed fuel according to claim 21 or 22, wherein the storage sealed container is provided with a temperature control device configured to control the temperature of the ammonia mixed fuel inside the storage sealed container so that the internal pressure of the storage sealed container is within a temperature range that does not exceed a set pressure resistance of the storage sealed container. 24. The apparatus for producing an ammonia mixed fuel according to any one of claims 21 to 23, wherein the temperature control device is configured to adjust a temperature of the ammonia mixed fuel so that, when the ammonia mixed fuel in the sealed storage container is stirred and mixed by the stirrer, an entire liquid phase portion of the ammonia mixed fuel is in a temperature range where the ammonia and the combustion improver are in a solution state in which they are dissolved in each other, or where the ammonia and the combustion improver are in an emulsion state, depending on a liquid phase composition of the ammonia mixed fuel. 25. The apparatus for producing an ammonia mixed fuel according to claim 20, further comprising a nitrogen gas introduction line connected to the sealed storage container, configured to introduce nitrogen gas into a gas phase portion in the sealed storage container at a discharge pressure equal to or higher than a saturated vapor pressure of the ammonia mixed fuel in the sealed storage container when the ammonia mixed fuel is discharged from the outlet . The storage sealed container has the outlet on a bottom surface of the storage sealed container,
The outlet is provided with a volumetric flow meter configured to continuously measure a volumetric flow rate of the ammonia mixed fuel discharged in a liquid phase from the outlet,
25. The device for producing an ammonia mixed fuel according to claim 20, further comprising an injection and discharge control mechanism configured to, when the ammonia mixed fuel is injected into the sealed storage container through the injection port, inject the ammonia mixed fuel until a predetermined amount equal to or less than a full filling amount of the sealed storage container, and, when the ammonia mixed fuel is discharged from the sealed storage container through the discharge port after the injection of the ammonia mixed fuel into the sealed storage container, continuously reduce an internal volume of the sealed storage container at a volume change rate approximately equal to the discharge volumetric flow rate measured by the volumetric flow meter while maintaining the airtightness and internal pressure of the sealed storage container. The storage airtight container comprises:
a cylinder having a body portion having an upright outer cylindrical shape and a constant internal cross-sectional area perpendicular to the axial direction of the outer cylindrical shape, and a bottom plate having the inlet and the outlet provided therein and sealing a lower end opening of the body portion;
A piston that can reciprocate up and down within the cylinder while maintaining airtightness;
a reciprocating drive device configured to reciprocate the piston in an up-down direction,
The injection and discharge control mechanism includes:
When the ammonia mixed fuel is injected into the sealed storage container through the injection port, the piston is pushed up in the cylinder by the reciprocating drive device to a predetermined full-fill position or a predetermined position below the full-fill position, and then stops;
27. The apparatus for producing an ammonia mixed fuel according to claim 26, further comprising: when the ammonia mixed fuel is discharged from the sealed storage container through the discharge port after the ammonia mixed fuel is filled, the piston is continuously pushed down by the reciprocating drive device at a linear velocity substantially equal to a value calculated by dividing the discharge volumetric flow rate measured by the volumetric flow meter by the internal cross-sectional area of the body of the cylinder while resisting the saturated vapor pressure of the ammonia mixed fuel in the sealed storage container, and then stops near the bottom plate. When the ammonia mixed fuel is injected into the sealed storage container through the injection port, the ammonia mixed fuel is injected until a predetermined amount equal to or less than a full-fill amount of the sealed storage container is reached,
25. The apparatus for producing an ammonia mixed fuel according to any one of claims 20 to 24, further comprising an injection and discharge control mechanism configured such that, when the ammonia mixed fuel is discharged from within the sealed storage container through the discharge port after the ammonia mixed fuel is injected into the sealed storage container, the ammonia mixed fuel is pushed out of the sealed storage container at a pressure higher than a saturated vapor pressure of the ammonia mixed fuel at a temperature of the ammonia mixed fuel in the sealed storage container, while maintaining the airtightness of the sealed storage container. The storage airtight container comprises:
a cylinder having an outer cylindrical shape, the cylinder having a body portion having a constant internal cross-sectional area perpendicular to the axial direction of the outer cylindrical shape, and a bottom plate having the inlet and the outlet provided therein and sealing an opening at one end of the body portion;
a piston capable of reciprocating in the axial direction while maintaining airtightness within the cylinder;
a reciprocating drive device configured to reciprocate the piston in the axial direction,
The injection and discharge control mechanism includes:
When the ammonia mixed fuel is injected into the sealed storage container through the injection port, the piston is pushed up to a predetermined full-fill position or a predetermined position lower than the full-fill position by the reciprocating drive device in the cylinder and then stopped;
27. The apparatus for producing an ammonia mixed fuel according to claim 26, wherein, when the ammonia mixed fuel is discharged from the sealed storage container through the outlet after the ammonia mixed fuel is filled, the piston is continuously pushed down by the reciprocating drive device at a pressure exceeding a saturated vapor pressure of the ammonia mixed fuel in the sealed storage container while maintaining the airtightness of the sealed storage container, and then stops near the bottom plate. The connecting mechanism is configured so that an introduction line for introducing the ammonia mixed fuel into the sealed storage container and the injection port are detachable from each other,
30. The apparatus for producing an ammonia-mixed fuel according to claim 20 , wherein the sealed storage container is mounted on a transport device in any one of a land area, a water area, and an airspace. The apparatus for producing an ammonia-mixed fuel according to any one of claims 6 to 30 ,
an ammonia mixed fuel supply line for supplying the ammonia mixed fuel discharged from the liquid phase discharge line to a combustor configured to combust the ammonia mixed fuel. The apparatus for producing an ammonia-mixed fuel according to any one of claims 19 to 30 ,
an ammonia mixed fuel supply line for supplying the ammonia mixed fuel discharged from the outlet of the sealed storage container to a combustor configured to combust the ammonia mixed fuel. 33. The ammonia mixed fuel supply device according to claim 31 or 32, wherein the ammonia mixed fuel supply line is provided with an ammonia mixed fuel supply machine configured to supply the ammonia mixed fuel to the combustor at a predetermined flow rate and a predetermined discharge pressure. The ammonia mixed fuel supply line is provided with a branching section that branches the ammonia mixed fuel at a predetermined ratio on the way to the combustor,
The ammonia mixed fuel supply device according to any one of claims 31 to 33, further comprising an ammonia mixed fuel reflux line configured to reflux a portion of the ammonia mixed fuel flowing through the ammonia mixed fuel supply line that is not supplied to the combustor and is branched off, into the mixing sealed container or the storage sealed container. A combustor configured to combust the ammonia mixed fuel according to any one of claims 1 to 5 ;
The ammonia mixed fuel supply device according to any one of claims 31 to 34 ,
and a combustion gas exhaust line configured to exhaust combustion gas generated by the combustion of the ammonia mixed fuel in the combustor into the atmosphere. The combustion gas exhaust line is provided with a selective catalytic reactor configured to decompose nitrogen oxides, which are by-produced when the ammonia mixed fuel is burned in the combustor, contained in the combustion gas, discharged from the combustion chamber of the combustor, and passed through the combustion gas exhaust line, by catalytic reduction using the ammonia or a vaporized gas of the ammonia mixed fuel. The ammonia mixed fuel combustion device according to claim 35 . 37. The ammonia mixed fuel combustion device according to claim 36, further comprising a selective catalytic reaction supply line configured to merge a predetermined amount of either the ammonia or the ammonia mixed fuel from either the ammonia storage sealed container for storing the ammonia or the storage sealed container for storing the ammonia mixed fuel with the combustion gas at a merging portion provided in the combustion gas discharge line between the combustion chamber and the selective catalytic reactor. a nitrogen oxide concentration meter and an ammonia concentration meter that are provided in the combustion gas exhaust line on the combustion chamber side of the junction of the selective catalytic reaction supply line and the combustion gas exhaust line, and are configured to measure the nitrogen oxide concentration and the ammonia concentration, respectively, on the combustion chamber side of the junction;
A supply amount calculation device configured to calculate the amount of the ammonia or the ammonia mixed fuel to be supplied through the selective catalytic reaction supply line based on the concentration results measured by each of the nitrogen oxide concentration meter and the ammonia concentration meter;
38. The ammonia mixed fuel combustion device according to claim 37, further comprising: a quantitative supply device that is provided in the selective catalytic reaction supply line and is configured to control the supply amount of the ammonia or the ammonia mixed fuel supplied through the selective catalytic reaction supply line based on the calculation result of the amount by the supply amount calculation device. The combustion device for an ammonia mixed fuel according to any one of claims 35 to 38 , wherein the combustor is used as an internal combustion engine configured to extract mechanical power by utilizing energy of the combustion gas generated by the combustion of the ammonia mixed fuel. An external combustion engine configured to extract mechanical power by utilizing the energy of the combustion gas generated by the combustion of the ammonia mixed fuel;
The ammonia mixed fuel combustion device according to any one of claims 35 to 38 , further comprising: a combustion gas transfer line configured to transfer the combustion gas from the combustor to the external combustion engine. A heat processing device configured to perform heat processing using the energy of the combustion gas generated by the combustion of the ammonia mixed fuel;
The ammonia mixed fuel combustion device according to any one of claims 35 to 38 , further comprising: a combustion gas transfer line configured to transfer the combustion gas from the combustor to the thermal processing device. A power generation facility that generates power in any one of land, water, and airspace,
At least one of the combustion device for the ammonia mixed fuel having the internal combustion engine according to claim 39 and the combustion device for the ammonia mixed fuel having the external combustion engine according to claim 40 is provided;
A generator configured to generate electricity by utilizing mechanical power extracted from the energy of the combustion gas of the ammonia mixed fuel by at least one of the internal combustion engine and the external combustion engine;
a power output terminal configured to output the power generated by the generator;
and a control mechanism configured to control an amount of power at the power output end. A transportation device configured to move or transport goods in any one of land, water, and airspace,
At least one of the combustion device for the ammonia mixed fuel having the internal combustion engine according to claim 39 and the combustion device for the ammonia mixed fuel having the external combustion engine according to claim 40 is installed,
A transportation device comprising a power conversion and transmission mechanism configured to utilize the mechanical power extracted from the energy of the combustion gas of the ammonia mixed fuel by at least one of the internal combustion engine and the external combustion engine as at least a part of the power for propelling the transportation device. A transportation device configured to move or transport goods in any one of land, water, and airspace,
The power generation facility according to claim 42 is mounted on the vehicle,
an electric propulsion mechanism configured to use the electric power output from the power generation facility as at least a part of the electric power required for propulsion of the transportation equipment by utilizing energy of the combustion gas of the ammonia mixed fuel;
an operation control mechanism configured to use the electric power for at least a portion of the electric power required for operation control of the transportation equipment; and
and a maintenance power supply mechanism configured to use the electric power for at least a portion of the power required for maintenance of the transportation equipment. 45. The transportation equipment according to claim 44, further comprising a power conversion transmission mechanism configured to convert the mechanical power extracted from the energy of the combustion gas of the ammonia mixed fuel by at least one of the internal combustion engine and the external combustion engine provided in the power generation facility into at least a part of the power for propelling the transportation equipment. A method for producing an ammonia-mixed fuel, comprising the steps of:
(1) liquefied ammonia;
(a) Liquefied petroleum gas, naphtha, gasoline, kerosene, and diesel;
(b) a feedstock hydrocarbon that is at least one hydrocarbon species contained as a component in any one of the liquefied petroleum gas, the naphtha, the gasoline, the kerosene, and the diesel; and
(c) a raw material alcohol having 3 or less carbon atoms;
and a combustion improver that assists the combustion of the ammonia, which is at least one of the above, is introduced into the mixing closed vessel;
(2) The ammonia and the combustion improver are stirred and mixed in the sealed mixing vessel while being kept in a gas-liquid equilibrium state with a liquid phase remaining, thereby producing a mixture in which at least a part of the liquid phase portions of the ammonia and the combustion improver are in a solution state in which the ammonia and the combustion improver are dissolved in each other, or in an emulsion state of the ammonia and the combustion improver;
(3) A method for producing an ammonia mixed fuel, comprising discharging the mixture from the sealed mixing vessel as an ammonia mixed fuel. 47. The method for producing an ammonia-mixed fuel according to claim 46, wherein, when the ammonia and the combustion improver are introduced into the mixing sealed container and stirred and mixed, a temperature of the mixture of the ammonia and the combustion improver is adjusted so that a saturated vapor pressure of the ammonia and the combustion improver in the mixing sealed container does not exceed a set withstand pressure of the mixing sealed container. In preparing the mixture,
The ammonia in the liquid state and the combustion improver in the liquid state are introduced into the mixing sealed vessel in a predetermined ratio;
The ammonia and the combustion improver are mixed by stirring in the sealed mixing vessel,
48. The method for producing an ammonia-mixed fuel according to claim 46 or 47, further comprising adjusting a temperature of the mixture so that the entire liquid phase portion of the mixture is in a temperature range in which the ammonia and the combustion improver are in a solution state in which they are dissolved in each other, or in an emulsion state of the ammonia and the combustion improver, according to the predetermined amount ratio. The ammonia mixed fuel contains, as the combustion improver, at least one of the liquefied petroleum gas, the feedstock hydrocarbon, and the feedstock alcohol,
The feedstock hydrocarbon is at least one hydrocarbon species contained as a component in the liquefied petroleum gas,
The method for producing an ammonia-mixed fuel according to any one of claims 46 to 48 , wherein the raw material alcohol is methanol. 50. The method for producing an ammonia mixed fuel according to any one of claims 46 to 49, wherein when discharging the mixture from the sealed mixing container, nitrogen gas is injected into the sealed mixing container at a discharge pressure equal to or higher than a saturated vapor pressure of the mixture in the sealed mixing container. 50. The method for producing an ammonia-mixed fuel according to any one of claims 46 to 49, wherein, when discharging the mixture from the mixing sealed container, the ammonia is continuously replenished into the mixing sealed container at a flow rate equal to a discharge flow rate of the ammonia contained in the mixture discharged from the mixing sealed container while being stirred and mixed, and in parallel, the combustion improver is continuously replenished into the mixing sealed container at a flow rate equal to a discharge flow rate of the combustion improver contained in the mixture discharged from the mixing sealed container while being stirred and mixed, thereby continuously producing the ammonia-mixed fuel in which a mixture composition of the ammonia and the combustion improver is maintained constant. 51. The method for producing an ammonia-mixed fuel according to any one of claims 46 to 50, wherein, when preparing the mixture, a surfactant is introduced into the sealed mixing container together with the ammonia and the combustion improver, and stirred and mixed to prepare the mixture in the emulsion state containing the surfactant as one component of the mixture. 53. The method for producing an ammonia-mixed fuel according to claim 52 , wherein the surfactant is introduced into the mixing sealed container so that the concentration of the surfactant in the mixture is 0.1 to 10 mass% when the mixture is prepared. 54. The method for producing an ammonia mixed fuel according to claim 52 or 53, wherein, when the ammonia mixed fuel in which a mixture composition of the ammonia and the combustion improver is maintained constant is continuously produced by the method according to claim 51 , when the mixture is discharged from the closed mixing container, the surfactant is continuously replenished into the closed mixing container at a flow rate equal to a discharge flow rate of the surfactant contained in the mixture discharged from the closed mixing container, thereby continuously producing the ammonia mixed fuel in which a concentration of the surfactant is maintained constant . 55. The method for producing an ammonia-blended fuel according to any one of claims 52 to 54 , wherein the surfactant comprises at least one non-ionic surfactant and at least one ionic surfactant. The surfactant is
(A) In the molecular structure, a primary or secondary amino group [-NH ₂ or >NH], a polyoxyalkylene amino group [>N(C _a H _2a O) _c -H or -N((C _b H _2b O) _d -H) ((C _b H _2b O) _e -H)] (a and b are 2 or 3, c is an integer of 1 to 8, d and e are 0 or positive integers such that d+e=1 to 8), an amide group [-C(=O)NH ₂ ], a polyoxyalkylene amide group [-C(=O)N((C _f H _2f O) _g -H) ((C _f H _2f O) _h -H)] (f is 2 or 3, g and h are 0 or positive integers such that g+h=1 to 8), and a polyoxyalkylene group [-O(C _i H _2i O) _j -H] (i is 2 or 3, j is an integer of 1 to 8),
and at least one of the nonionic surfactants having at least one alkyl group [C _k H _2k+ 1 -] (k is an integer of 7 to 18) and an alkenyl group [C _l H _2l-1 -] (l is an integer of 7 to 18) as a nonpolar moiety;
(B) in its molecular structure, it has at least one of the following ionic polar sites: a quaternary methylammonium group, a quaternary methylalkanolammonium group, or a quaternary alkanolammonium group [-N ⁺ (CH ₃ ) _p (C _m H _2m OH) _q.X ^- , or >N ⁺ (CH ₃ ) _r (C _n H _2n OH) _s.X ' ^- ] (m and n are 2 or 3, p and q are 0 or positive integers such that p + q = 3, r and s are 0 or positive integers such that r + s = 2, and X and X' are any of Cl, Br, and I), and a carboxyl group [-C(=O)OH];
and at least one of the ionic surfactants having at least one alkyl group [C _t H _2t+1 -] (where t is an integer from 7 to 18) and at least one alkenyl group [C _u H _2u-1 -] (where u is an integer from 7 to 18) as a non-polar moiety. 57. The method for producing an ammonia-mixed fuel according to any one of claims 46 to 56, wherein, when all of the targets to be introduced into the sealed mixing container, including the ammonia and the combustion improver, are introduced into the sealed mixing container in order of the targets to be introduced, starting with the target having a lower saturated vapor pressure at a temperature inside the sealed mixing container. introducing the ammonia and the combustion improver into the mixing sealed vessel at a predetermined ratio so that the entire liquid phase portion of the mixture is in a solution state or an emulsion state when the ammonia and the combustion improver are stirred and mixed in the mixing sealed vessel, and stirring and mixing are performed in the mixing sealed vessel while maintaining the temperature at a predetermined liquid phase temperature;
The method for producing an ammonia-mixed fuel according to any one of claims 46 to 57, wherein the liquid phase portion is discharged from the mixing sealed container to produce an ammonia-mixed fuel in which the ammonia and the combustion improver are in a solution state or an emulsion state at a composition ratio within a predetermined range. The combustion improver is at least one of those described in (a) and (b),
introducing the ammonia and the combustion improver into the mixing sealed vessel at a predetermined ratio, and stirring and mixing in the mixing sealed vessel while maintaining a predetermined liquid phase temperature, so that when the ammonia and the combustion improver are stirred and mixed in the mixing sealed vessel, a liquid phase portion of the mixture is separated into upper and lower two layers, and each of the liquid phase portions separated into the upper and lower two layers is entirely in a solution state or an emulsion state;
47. The method for producing an ammonia mixed fuel according to claim 46, wherein the liquid phase portion of at least one of the upper and lower two layers is discharged from the mixing sealed container, thereby producing one or two ammonia mixed fuels in which the ammonia and the combustion improver are in a solution state or an emulsion state at one or two predetermined composition ratios.

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