JPS5847213B2 - Slurry continuous extraction method under high pressure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a method for extracting coal liquefied oil contained in a high-pressure vessel to a low-pressure vessel.

In the direct hydrogenation and liquefaction reaction of coal, solid powder is reacted with liquid or gas under high pressure, so liquefied coal oil containing unreacted coal, inorganic substances in coal, powdered catalyst, etc. under high pressure is obtained as a product. It will be done.

Such high-pressure coal liquefied oil needs to be reduced to a low pressure to make it suitable for subsequent solid-liquid separation and transportation, but since coal liquefied oil contains fine solid powder, it is not as easy to use as a normal liquid. are different and involve various difficulties.

For example, when directly hydrogenating and liquefying coal, conventional methods yield a mixture of high-pressure coal liquefied oil and gas containing medium oil, product oil, unreacted coal, coal minerals, and powdered catalyst;
This mixture is introduced into a high-pressure gas-liquid separation tank, where the gas and coal liquefied oil are separated, and then the high-pressure coal liquefied oil is lowered by a pressure regulating valve to become low-pressure coal liquefied oil.

In such conventional methods, high-pressure coal liquefied oil passes through a pressure regulating valve at high speed due to pressure drop.
A problem arises in that the valve seat and valve stem are severely worn away by the solid powder in the coal liquefied oil.

For this reason, these valve seats and valve stems are made using wear-resistant materials such as tungsten carbide, artificial ruby, and artificial sapphire, but even with these wear-resistant materials, satisfactory results cannot be obtained. Frequent replacement of these parts was required.

Replacing such parts is not only expensive, but also requires a temporary interruption of continuous operation, which significantly impairs the economics of the process. In addition, the conventional method requires external mechanical force for stirring to prevent sedimentation and separation of solid powder in coal liquefied oil, which is economically disadvantageous, and also requires sufficient stirring effectiveness. There was also the problem that it was not possible to obtain

The inventors of the present invention have conducted intensive research to fundamentally solve the above-mentioned problems associated with converting conventional high-pressure coal liquefied oil into low-pressure coal liquefied oil. Forms high-pressure coal liquefied oil that generates gas pressure by dispersing air bubbles in advance or by dissolving gas in the oil or by lowering the pressure by expanding the air bubbles and vaporizing the dissolved gas, and This high-pressure coal liquefied oil is first introduced and stored in a measuring container, and communication with the high-pressure container is cut off and sealed, and then this measuring container is communicated with a low-pressure container, and the pressure drop at that time causes the coal to liquefy. These gas pressures are generated in the measuring container by expanding the air bubbles contained in the oil and vaporizing the dissolved gases, and this generated gas pressure is used to transfer the coal liquefied oil in the measuring container to a low-pressure container. It has been discovered that by doing so, extremely advantageous extraction of high-pressure coal liquefied oil can be achieved, and the present invention has been completed.

That is, according to the present invention, when extracting the coal liquefied oil stored in the high pressure container into the low pressure container, the coal liquefied oil under high pressure containing bubbles and/or dissolved gas is once transferred from the high pressure container to the measuring container under high pressure. After storing and sealing the coal liquefied oil as it is, the measuring container under high pressure is communicated with a low pressure container to lower the internal pressure of the measuring container, and the pressure drop expands the bubbles contained in the coal liquefied oil and/or removes the dissolved gas. A method for extracting liquefied coal oil under high pressure is characterized in that the liquefied coal oil in a measuring container is transferred to a low pressure container by the gas pressure generated by the expansion of bubbles and/or the vaporization of dissolved gas. provided.

Note that the term "liquefied coal oil" as used in the present invention is broadly interpreted and is defined as an oil that is generated when coal is treated under high pressure using hydrogen and is a liquid containing solid content.

In the present invention, first, air bubbles are dispersed and/or gas fractions are dissolved in coal liquefied oil in a high pressure vessel.

This dispersion of bubbles and/or dissolution of gases can cause hydrogen, nitrogen, air, oxygen, ammonia, carbon dioxide, hydrogen sulfide, lower hydrocarbons (methane, ethane, propane, methane, etc.), This is achieved by ejecting other gaseous substances through a nozzle.

This can also be achieved by mixing gas with the liquefied coal oil and introducing it into the high-pressure container through a nozzle when storing the liquefied coal oil in the high-pressure container.

The amount of gas contained in the form of bubbles and/or dissolved in the coal liquefied oil varies depending on the properties of the coal liquefied oil, the type of gas, the pressure difference between the high pressure container and the low pressure container, etc. When the measuring container is filled with dissolved gas and/or bubble gas, it is sufficient to reach a pressure higher than that of the low pressure container.

The gas dispersed as bubbles in the coal liquefied oil is produced by storing and sealing the coal liquefied oil in a measuring container, communicating the measuring container with a low pressure container to lower the internal pressure of the measuring container, and then responding to the pressure drop. The liquefied coal oil expands in volume and generates gas pressure that forces the liquefied coal oil in the measuring container into the low-pressure container.The gas dissolved in the liquefied coal oil also vaporizes due to this pressure drop, and the gas flows into the measuring container. Generates pressure.

When coal is directly hydrogenated and liquefied, the liquefied product from the reactor is sent to a high-pressure gas-liquid separation tank where it is separated into gas and liquid, but in this case, the separated liquefied coal oil already contains hydrogen and hydrogen. ,
Lower hydrocarbons (CH4, C2H6,
C3H8, C4H1o, etc.) and inorganic gases (CO2, C
O, H2S, NH3, etc.) are dissolved in large quantities, so no special gas introduction operation is required, and this coal liquefied oil can be used as it is as coal liquefied oil to be transferred to the next measuring container.

Of course, if necessary, gas for forming bubbles can be injected into the coal liquefied oil.

In this case, the jet of gas into the coal liquefied oil not only increases the propulsive force for extracting and transferring the coal liquefied oil in the measuring container to the low-pressure container, but also serves as a stirring force for the coal liquefied oil. , to prevent settling of solids from coal liquefied oil.

In the conventional method, a stirring blade was rotated to prevent the solid content from settling from the coal liquefied oil in the high-pressure gas-liquid separation tank, but in the case of the present invention, as described above, the gas after the reaction is By squirting coal into liquefied oil in a high-pressure gas-liquid separation tank,
The use of such stirring blades can be omitted.

Next, in the present invention, the coal liquefied oil in the high pressure container is
Store tightly in a measuring container.

This metering container consists of a high pressure sealed container equipped with a coal liquefied oil inlet valve and a coal liquefied oil discharge valve, the inlet valve is connected to the high pressure container, and the discharge valve is connected to the low pressure container.

To transfer and seal the liquefied coal oil in the high-pressure container to this metering container, close the discharge valve, open the inlet valve to accommodate a certain amount of high-pressure liquefied coal oil, and then close the inlet valve. do.

When high-pressure coal liquefied oil is contained and sealed in a measuring container in this way, the amount of coal liquefied oil is determined by the volume of the measuring container and not by the flow rate adjustment of the inlet valve. The diameter of the valve can be selected arbitrarily large, so that the mass velocity of the coal liquefied oil passing through this valve can be reduced, and therefore the wear of the valve is also necessarily reduced.

Furthermore, when high-pressure coal liquefied oil is stored in a measuring container according to the present invention, since the measuring container is airtight,
The flow rate of the high pressure coal liquefied oil introduced into the measuring container is:
It becomes smaller depending on the amount of high-pressure coal liquefied oil introduced, and as a result, the wear of the valve mentioned above becomes even less due to this effect.

Next, in the present invention, the high-pressure coal liquefied oil stored and sealed in the measuring container as described above opens the discharge valve of the measuring container to communicate the inside of the measuring container with the low-pressure container.

This operation causes the internal pressure of the measuring container to drop, but in response to this pressure drop, the bubbles contained in the coal liquefied oil expand and/or the dissolved gases evaporate, causing these to remain in the measuring container. A new gas pressure is generated, and this self-generated pressure forces the coal liquefied oil contained in the metering container into the low-pressure container.

In this case, the gas pressure generated in the metering container before communicating with the low-pressure container is equal to the pressure in the high-pressure container, but the internal pressure drops rapidly by communicating with the low-pressure container.

Therefore, since most of the coal liquefied oil in the metering container is pumped to the low pressure container at such a reduced pressure,
Naturally, the wear on the discharge valve is also reduced.

Furthermore, when the coal liquefied oil in the measuring container is drawn out into the low-pressure container in this way, there is no need to send gas that becomes the driving force for drawing out the coal liquefied oil into the measuring container. Even if there is a liquid seal in the pipe connecting the coal liquefied oil and the low pressure vessel, there will be no problem in extracting the coal liquefied oil.

Therefore, in the case of the present invention, the coal liquefied oil from the metering vessel does not need to be introduced into the head space of the low pressure vessel, but can be introduced into the coal liquefied oil phase in the bottom or middle of the vessel.

This means that the energy of the coal liquefied oil spilled at this time can be used as energy for stirring the coal liquefied oil in the low-pressure container, and unlike the conventional case, there is no need to install a special stirrer for the low-pressure container. Alternatively, even if a stirrer is installed, it has the advantage that it can be small.

According to the present invention, as described above, unlike conventional methods, coal liquefied oil in a high-pressure container can be extracted or transferred to a low-pressure container extremely smoothly and stably, and moreover, it is applicable to the case of the present invention. The design of the valve is extremely simple, as it does not need to precisely adjust the flow rate, but merely has the function of opening and closing the flow of coal liquefied oil.

In addition, as mentioned above, the flow rate of coal liquefied oil passing through this valve can be significantly reduced compared to the conventional case, so its wear is also significantly reduced, making long-term continuous operation of the process difficult in the past. becomes possible.

The flow rate of the coal liquefied oil according to the present invention is determined by the metering container without using the flow rate regulating valve, so that extremely stable extraction of the coal liquefied oil can be achieved.

In the case of the present invention, in order to obtain a large flow rate of coal liquefied oil, a plurality of these measuring containers may be installed and these may be operated simultaneously, alternately, or periodically.

In the case of the present invention, stirring of the coal liquefied oil in the container can be accomplished by the kinetic energy of the coal liquefied oil or coal liquefied oil/gas mixture, so no special stirring equipment is required.

That is, stirring of the coal liquefied oil in the high pressure container is achieved by dispersing air bubbles in the coal liquefied oil or blowing out a gaseous substance for dissolving gas, and the coal liquefied oil in the low pressure container is This can be achieved by introducing the coal liquefied oil/gas mixture from a metering vessel into the liquefied oil.

The present invention is useful for extracting not only coal liquefied oil but also produced oil containing solid particles produced by heavy oil such as coal refining, cracking and refining of tar sand, oil shale, etc. from a high-pressure container to a low-pressure container. Applicable.

In the case of the present invention, there is no particular restriction depending on the internal pressure of the container, but in general, in the case of a high-pressure container, the internal pressure of the container is 2 to 10
001<g/crit and 1 to 50 for low pressure vessels
It is in the range of 0 kg/ffl.

In particular, the present invention reduces the pressure of high-pressure coal liquefied oil by several hundred to one
Hereinafter, it is preferably applied particularly to lowering the temperature to about 1/10 to 1/1000.

The present invention is particularly suitable for extracting high pressure coal liquefied oil coexisting with gas.

In such a case, no special operation is required to introduce gas into the coal liquefied oil, and the coal liquefied oil in the presence of gas may be accommodated in a high-pressure container through a nozzle.

Next, embodiments of the present invention will be described with reference to the drawings.

In this figure, 4 is a coal liquefaction reactor, 9 is a high-pressure gas-liquid separation tank, 20 and 23 are measuring containers, and 28 is a low-pressure receiving tank.

Coal liquefied oil with a concentration of about 40% by weight is passed through a high-pressure pump 1,
and hydrogen gas are respectively introduced into a reactor 4 via a hydrogen compressor 2 and a preheater 3, where liquefied coal oil and hydrogen react to liquefy the coal.

In this case, the general reaction conditions are salinity 350-500°C
1 pressure is 20 to 700 Yu/cwL.

The reaction mixture of coal liquefied oil (hereinafter simply referred to as coal liquefied oil) produced by this reaction, unreacted hydrogen gas, and cutting gas is heat-recovered in a heat exchanger 5, and then passed through a line 6 or 7 under high pressure. Coal liquefied oil phase 11 in gas-liquid separation tank 9
is introduced through the bottom nozzle.

In this case, a part of the reaction mixture may be introduced into the gas phase 10 of the high-pressure gas-liquid separation tank 9 through the line 8 in order to adjust the degree of stirring of the coal liquefied oil phase 1j.

Next, an example of the composition of the reaction mixture extracted from the reactor 4 is shown in which the coal liquefied oil content is 70% by weight and the gas content is 30% by weight.
% by weight, and the solid concentration in coal liquefied oil is 20% by weight.
It is.

In addition, the total gas content in this coal liquefied oil is 0.6
% by weight, of which 0.5% by weight in the form of bubbles and 0.1% by weight as dissolved gas.

Further, in this embodiment, the internal pressure of the high-pressure gas-liquid separation tank 9 is 30
0, and on the other hand, the internal pressure of the low pressure tank 28 is 1 kg/-
It was set to

By such an operation, the coal liquefied oil can be uniformly stirred, and as a result, (a) sedimentation of the slurry is prevented and fluidity suitable for extraction of the coal liquefied oil is obtained.

(b) The temperature distribution of the coal liquefied oil phase is made uniform.

(c) Advantages such as formation and dispersion of air bubbles in coal liquefied oil are most easily achieved.

The coal liquefied oil in the high-pressure gas-liquid separation tank 9 is transferred to the coal liquefied oil outlet pipe 1 in response to the opening of the inlet valves 19 and 20 of the measuring container (in this case, the discharge valves 21 and 24 are in the closed state).
8 and valve 18' into the metering vessel.

After this coal liquefied oil is charged, the inlet valves 19 and 20 are closed, and the discharge valves 21 and 24 are opened, and the inside of the measuring container is communicated with the low pressure receiving tank 28, and accordingly, the coal in the measuring container is As described above, the liquefied oil is forced into the low-pressure receiving tank 28 by the gas pressure generated by the expansion of the gas contained in the coal liquefied oil and the gas vaporization.

In this case, high pressure (pressure 300 ky) with the composition as described above is used.
/cwt) Coal liquefied oil is transferred from the measuring volume to the low pressure receiving tank (pressure 1
The gas pressure generated when transferring kg/criY) is
60 ky/cI at its highest? LH1f, which is significantly reduced compared to the case where the internal pressure of the high-pressure gas-liquid separation tank is 300 kg/criL as a back pressure and is pumped to the low-pressure receiving tank.

Note that the first valve 18' is an emergency extraction stop valve,
Not because of pressure drop.

This valve 18' is intended to be automatically activated, for example, when the liquid level in the high-pressure gas-liquid separation tank 9 drops abnormally, or when the reactor 4 and other parts become abnormally high in pressure and temperature. , is open during normal operation.

The series of operations described above is carried out using the liquid level detection device 14, which includes a liquid pressure detection tube 12 and a gas pressure detection tube 13, each having a nozzle at its tip, and the inlet valve 19, 22, discharge valve 21, . 24 and a sequencer 15 electrically connected to the liquid level detection device 14.

In this case, the liquid level detection device 14 is composed of a diaphragm type differential pressure receiver, which passes through a line 17 on the discharge side of the hydrogen compressor 2 and hydrogen circulation compressor 16, and passes through a line 17 at the ends of the liquid pressure detection tube 12 and the pressure detection tube 13. It detects the differential pressure of hydrogen gas ejected from each source and converts it into an electrical signal.

This liquid level detection method is preferable because it is simple in terms of equipment and is functionally stable against external disturbances, but other methods include the differential pressure detection method using the seal subtraction method, the gamma ray method, X-ray method, ultrasonic method, capacitance method, phototube method,
Other conventional methods such as float methods are also applicable.

The measuring vessel is a normal small pressure vessel with an inlet valve and a discharge valve attached, and the drawing shows an example in which two are arranged between the high-pressure gas-liquid separation tank 9 and the low-pressure receiving tank 28. ing.

One or more of these measuring containers can be provided, and each valve of the measuring container can be operated arbitrarily according to the program of the sequencer 15.

For example, it is possible to operate the two measuring vessels shown in the drawing alternately or simultaneously, or to operate these measuring vessels at a predetermined cycle, and it is possible to operate the measuring vessels most suitable for the purpose or to operate them simultaneously. Coal liquefied oil can be extracted.

The internal volume and number of measuring containers are appropriately determined depending on the discharge amount of the coal slurry pump.Theoretically, the product of the number of extractions per hour and the internal volume is calculated for each measuring container. , the sum of the calculated values should be equal to the amount of product calculated from the discharge amount of the coal slurry pump per hour.

However, in practice, certain restrictions arise due to the structure of the coal liquefaction reactor and high-pressure gas-liquid separation tank, the allowable pressure changes within the high-pressure system, etc. is appropriately determined in accordance with the characteristics of the liquefaction reactor so that stable extraction of coal liquefied oil can be achieved.

By disposing a measuring container between such a high-pressure gas-liquid separation tank and a low-pressure receiving tank and extracting high-pressure coal liquefied oil, (a) valve wear can be avoided; (b)
(C) Even if there is a liquid seal in the piping between the measuring container and the low-pressure receiving tank, it will not interfere with the extraction of the coal liquefied oil. This provides advantages such as no damage to coal, making it possible to extract high-pressure coal liquefied oil continuously and stably for a long period of time.

The mixture of coal liquefied oil and released gas extracted from the measuring container 20.23 is introduced into the coal liquefied oil phase of the low pressure receiving tank 28 through the coal liquefied oil inlet pipe 25, 26, and this introduction causes the coal in the tank to The liquefied oil is stirred.

The introduction pipe 27 for introducing the coal liquefied oil into the gas phase is provided to control the amount of coal liquefied oil introduced from the introduction pipes 25 and 26, and is not necessarily required.

The coal liquefied oil temporarily stored in this low pressure receiving tank is sent to the coal liquefied oil refining system via line 32 and pump 29.

The line 30 is a backup piping for preventing the line 32 from being blocked by coal liquefied oil when the operation is stopped, and can also be used to control the flow rate of the pump 29 during normal operation.

Gas released from the coal liquefied oil is sent to the gas purification system via line 31.

As mentioned above, in the case of the present invention, the gas pressure for pumping coal liquefied oil to the low-pressure receiving tank is self-generated within the metering container, and is not due to gas pressure introduced from the outside. The coal liquefied oil can be introduced into the bottom and/or the middle of the coal liquefied oil phase in the tank, and very good coal liquefied oil stirring can be achieved.

Therefore, in the case of the present invention, it is not necessary to use a special stirring device equipped with conventional stirring blades for stirring coal liquefied oil.

In the present invention, as described above, the measuring container and the low pressure container as the high pressure container pressure drop section are integrally connected, and such a coal liquefied oil extraction system allows the flow from the high pressure container to the low pressure container. The highly advantageous extraction of liquefied oil from coal is distantly related.

The present invention can be applied to various applications, such as direct hydrogenation of coal, liquefied coal, coal extraction hydrogenation and liquefaction, coal carbonization hydrogenation, tar sand bitumen, oil shale oil, etc. It is also applied to the extraction of solid-containing product oil produced in liquid-phase hydrogenation reactions.

Furthermore, the present invention is applicable to the extraction of high-pressure liquids that do not contain solids, in addition to solids-containing coal liquefaction product oil, for example,
It is also applied to the extraction of high-pressure heavy oil from heavy oil hydrodesulfurization equipment.

Furthermore, the present invention can be modified in various ways. For example, in the apparatus system shown in the drawings, coal liquefied oil can be extracted directly from the reactor 4 to the low-pressure receiving tank 28 without going through the high-pressure gas-liquid separation tank 9. It is also possible to further cool the gas separated in the high-pressure gas-liquid separation tank 9 and extract the condensed heavy oil from the high-pressure system to the low-pressure system.

Furthermore, by installing a power recovery turbine between the measuring container 20, 23 and the low pressure receiving tank 28, the kinetic energy of the extracted coal liquefied oil and the expansion energy of the extracted gas can be recovered as motive power or electric power. .

[Brief explanation of the drawing]

The drawing shows an example of an apparatus system diagram for implementing the present invention. 4...Reactor, 9...High pressure gas-liquid separation tank, 20.23
...Measuring container, 19.22...Inflow valve, 21゜24...Outflow valve, 28...Low pressure receiver, 14...
・Liquid level detection device, 15...Sequencer-8

Claims (1)

[Claims] 1. When extracting the coal liquefied oil stored in the high-pressure container Cζ into the low-pressure container, the coal liquefied oil under high pressure containing bubbles and/or dissolved gas is first transferred from the high-pressure container to the measuring container under high pressure. After storing and sealing the coal liquefied oil as it is, the measuring container under high pressure is communicated with a low pressure container to lower the internal pressure of the measuring container, and the pressure drop expands the bubbles contained in the coal liquefied oil and/or releases the dissolved gas. Coal liquefied oil extraction power point 2 under high pressure, characterized in that the coal liquefied oil in the measuring container is transferred to a low pressure container by the gas pressure generated by the expansion of the bubbles and/or the vaporization of the dissolved gas. Claim 1: When transferring the liquefied coal oil in the measuring container to the low-pressure container, the liquefied coal oil is introduced into the liquid phase of the low-pressure container together with gas, and the liquefied coal oil in the low-pressure container is stirred. the method of.