JP7724691B2 - Method for producing propylene using a raw material liquid containing glycerin and hydrogen as raw materials - Google Patents

Description

The present invention relates to a method for producing propylene using a raw material liquid containing glycerin and hydrogen as raw materials. Furthermore, the present invention includes catalyst technology that utilizes waste glycerin containing impurities as a raw material.

Propylene is a useful compound used as a raw material monomer for polypropylene and as a substrate for acrylonitrile. Traditionally, propylene has been produced industrially by methods such as cracking naphtha or liquefied petroleum gas, dehydrogenating propane, and using MTO (methanol to olefin) technology. However, most of the raw materials used in these manufacturing processes are derived from fossil fuels, and from the perspective of environmental conservation, there is a desire to switch to manufacturing methods that use biomass as a raw material.

Glycerin is a biomass-derived chemical produced through a multi-stage refining process of waste glycerin, a by-product of the production of biodiesel from animal and vegetable oils. However, most of the waste glycerin produced as a by-product is discarded without being used, and so it has attracted attention as an unused biomass resource. The reason for the lack of progress in using waste glycerin as a raw material is that it contains a variety of impurities, primarily soap, alkaline components, and ash, which are also by-products in the production of biodiesel.

Waste glycerin refers to the hydrophilic phase containing glycerin obtained by reacting animal and vegetable oils with methanol in the presence of a base catalyst such as potassium hydroxide, followed by removal of the oil (biodiesel). A typical composition is 80% by mass or less of glycerin, 10% by mass or less of ash, and 10% by mass or more of soap components, but the composition of waste glycerin is not limited to this.

When producing propylene from biomass resources, glycerin, which also has three carbon atoms, is a promising candidate compound. Many conversion technologies have been developed to date, and Patent Documents 1, 2, 3, 4, and 5, as well as Non-Patent Document 2, disclose methods for producing propylene from glycerin and feedstocks prepared by diluting glycerin with a solvent. Patent Document 6 and Non-Patent Document 1 disclose technologies for producing propylene through a gas-phase reaction using feedstocks prepared by diluting waste glycerin, a by-product in biodiesel production.

CN103224440A WO2016/078673A JP2016-56147A CN103274886A WO2010/012060A2 JP5721238

Journal of Japan Petroleum Institute, 2014, 57, 197 Green Chemistry, 2015, 17, 903

When using waste glycerin as a raw material, soap, ash, and alkaline components can deactivate the catalyst. In particular, because soap and alkaline components contain inorganic components, they do not volatilize even when subjected to high temperatures, such as during calcination, and remain on the catalyst, making catalyst regeneration difficult and preventing long-term operation of gas-phase reactions using waste glycerin as a raw material. In fact, Patent Document 6, which uses waste glycerin as a raw material, clearly states that "catalytic activity tends to decrease when the amount of alkali metal supported on the catalyst exceeds a certain level. Therefore, the conversion reaction should be performed under conditions that make it difficult for the alkali metal contained in the raw material to precipitate on the catalyst surface (e.g., by reducing the alkali metal concentration in the reaction liquid)." Therefore, gas-phase reactions require measures such as reducing the alkali metal concentration in the raw material. On the other hand, in liquid-phase reactions, alkali components are also dissolved in the liquid, so deposition of alkali components (synonymous with alkali metals) on the catalyst surface is expected to be avoided. Therefore, when using waste glycerin as a raw material, it is desirable to develop a liquid-phase reaction system. Another advantage of liquid phase reaction systems is that gaseous propylene spontaneously separates from the liquid phase, which is the reaction site, under reaction conditions, resulting in better separation efficiency than gas phase reaction systems.

In addition, the alkaline components make the liquid more alkaline, and in order to demonstrate catalytic activity in the presence of the various impurities mentioned above, it is preferable to use a solid catalyst with a stronger inorganic structure than a complex catalyst. Furthermore, compared to solid catalysts, complex catalysts require a great deal of energy to separate and purify the catalyst, placing a greater burden on the environment. Therefore, from an environmental conservation perspective, this is a technology that should be avoided, especially when utilizing biomass resources.

For these reasons, it is desirable to develop technology to convert glycerin to propylene under liquid-phase conditions; however, to promote this conversion reaction under liquid-phase conditions, lower temperatures and higher-pressure hydrogen conditions are required compared to gas-phase conditions.

Patent Documents 1, 2, 3, 4, and 5, as well as Non-Patent Document 2, disclose propylene synthesis using a glycerin raw material that does not contain alkaline components as a substrate, but do not clarify the tolerance to impurities contained in waste glycerin. Furthermore, Patent Documents 1, 3, 4, and 5 produce propylene using a gas-phase reaction, so, as mentioned above, waste glycerin cannot be used as a raw material. Patent Document 2 and Non-Patent Document 2 disclose propylene synthesis in a liquid phase, but Patent Document 2 uses a complex catalyst. Furthermore, Non-Patent Document 2 investigates propylene synthesis using a solid catalyst in a liquid phase, but the catalytic activity is low, and a hydrogen pressure of approximately 8 MPaG is required to selectively obtain propylene, which requires significant energy costs and is therefore not industrially suitable.

Patent Document 6 and Non-Patent Document 1 published by the same research group disclose studies using waste glycerin as a raw material, but propylene is synthesized using a gas-phase reaction, and long-term operation as described above is not possible.

As described above, there is still room for improvement in methods for producing propylene from glycerin (not limited to waste glycerin). Therefore, the present invention aims to provide a production method that can synthesize propylene by reacting glycerin with hydrogen in the liquid phase using a solid catalyst under mild conditions.

As a result of extensive research to achieve the objectives of the present invention, the inventors have discovered that propylene can be obtained in good yield under easily controllable conditions by reacting a raw material liquid containing glycerin with hydrogen in the liquid phase in the presence of a solid catalyst containing one or more metal elements selected from the group consisting of metal elements of Groups 9, 10, and 11 of the periodic table.

That is, the present invention is as follows.
[1]
A method for producing propylene, comprising a step of reacting a raw material liquid containing glycerin with hydrogen in a liquid phase in the presence of a solid catalyst containing one or more first metal elements selected from the group consisting of metal elements of Groups 9, 10, and 11 of the periodic table.
[2]
The method according to [1], wherein the raw material liquid contains 10.0% by mass or more and 98.5% by mass or less of glycerin and 30% by mass or less of an alkali metal component.
[3]
The method according to [1] or [2], wherein the raw material liquid contains 10.0% by mass or more and 80.0% by mass or less of glycerin and 0.5% by mass or more and 30% by mass or less of an alkali metal component.
[4]
[4] The method according to any one of [1] to [3], wherein the raw material liquid contains an alkali metal component, and the amount of the alkali metal component is 1 part by mass or more per 160 parts by mass of the glycerin.
[5]
The method according to any one of [1] to [4], wherein the raw material liquid contains glycerin produced as a by-product during biodiesel production.
[6]
The manufacturing method according to any one of [1] to [5], wherein the solid catalyst further contains one or more second metal elements selected from the group consisting of tungsten, molybdenum, rhenium, and vanadium.
[7]
The manufacturing method according to any one of [1] to [6], wherein the first metal element is one or more metal elements selected from the group consisting of palladium, platinum, silver, and gold.
[8]
The production method according to any one of [1] to [7], wherein the reaction produces a gas containing a hydrocarbon, and the hydrocarbon contains propylene and propane in a total amount of 70 mass% or more.
[9]
[8] The production method according to [8], wherein the ratio of the number of moles of propylene to the total number of moles of propylene and propane is 30 mol% or more.
[10]
The manufacturing method according to any one of [1] to [9], wherein the hydrogen addition pressure is 0.1 MPaG or more and 5.0 MPaG or less at room temperature.

The present invention provides a method for producing propylene using glycerin and hydrogen as raw materials under mild liquid phase conditions. Furthermore, the present invention also makes it possible to utilize waste glycerin containing impurities as a raw material.

The present invention will be described in detail below. Note that the present invention is not limited to the following embodiment (present embodiment), and can be implemented in various modifications within the scope of its gist.

[Propylene production method]
The method for producing propylene according to the present embodiment includes reacting a raw material liquid containing glycerin with hydrogen in a liquid phase in the presence of a solid catalyst (hereinafter also simply referred to as a "solid catalyst") containing one or more metal elements selected from the group consisting of metal elements of Groups 9, 10, and 11 of the periodic table (hereinafter also referred to as a "first metal element" to distinguish it from a second metal element described below).

[1] Reaction Step The reaction step is a step of reacting a raw material liquid containing glycerin with hydrogen in a liquid phase in the presence of a solid catalyst. The reaction step of this embodiment can be carried out by a conventional method such as a batch method, a semi-batch method, or a continuous method. The reaction step of this embodiment may also include a separation step of purifying propylene. This embodiment is characterized in that glycerin and hydrogen are reacted in a liquid phase and propylene is recovered as a gas.

[2] Solid Catalyst In the propylene production method of this embodiment, a solid catalyst is used. As used herein, the term "solid catalyst" refers to a catalyst that is in a solid state in the liquid phase in the production method of this embodiment. The solid catalyst contains one or more first metal elements selected from the group consisting of metal elements of Groups 9, 10, and 11 of the periodic table.

Examples of the first metal element include cobalt, rhodium, iridium, nickel, palladium, platinum, copper, silver, and gold. Among these, from the viewpoint of excellent catalytic activity, the first metal element is preferably one or more elements selected from the group consisting of rhodium, iridium, palladium, platinum, silver, and gold. From the viewpoint of excellent selectivity, the first metal element is more preferably one or more elements selected from the group consisting of palladium, platinum, silver, and gold, and even more preferably one or more elements selected from the group consisting of silver and gold.

From the viewpoint of excellent catalytic activity, it is more preferable that the solid catalyst further contains, in addition to the first metal element, one or more second metal elements selected from the group consisting of tungsten, molybdenum, rhenium, and vanadium.

The combination of the first metal element and the second metal element is not particularly limited, but a combination of one or more first metal elements selected from the group consisting of palladium, platinum, silver, and gold and one or more second metal elements selected from the group consisting of tungsten, molybdenum, rhenium, and vanadium is preferred.

The content of the metal element in the solid catalyst (the total amount of the first and second metal elements if a second metal element is included) is preferably 0.5 to 50 mass% relative to the mass of the support, and from the viewpoint of excellent catalytic activity, is more preferably 1 to 40 mass%.

The content of each metal element is expressed as a percentage by mass of each metal element when the mass of the support is taken as 100% by mass. For example, a catalyst expressed as 10% by mass _M1 * 5% by mass _M2 /support has a mass ratio of _M1 : _M2 :support = 10:5:100.

When the solid catalyst contains a first and a second metal element, the mass ratio of the first metal element to the second metal element is not particularly limited, but may be, for example, 1:0.1-10, 1:0.5-5, or 1:1-3.

The content of metal elements and other substances in the solid catalyst is measured using a calibration curve method with an X-ray fluorescence analyzer. For example, a Rigaku "ZSX Primus II" X-ray fluorescence analyzer is used.

The carrier can be, for example, any of metal oxides and carbonaceous carriers. Examples of such carriers include titanium oxide, cerium oxide, lanthanum oxide, zirconium oxide, cerium oxide, magnesium oxide, molybdenum oxide, niobium oxide, cobalt oxide, nickel oxide, zinc oxide, calcium oxide, barium oxide, titanium nitride, alumina, silica, zeolite, silica alumina, yttria-stabilized zirconia, ceria-zirconia solid solution, lanthanum oxide-zirconia solid solution, hydroxyapatite, hydrotalcite, organic polymers, and activated carbon. Among these, from the viewpoint of excellent catalytic activity, titanium oxide, lanthanum oxide, cerium oxide, niobium oxide, zirconium oxide, magnesium oxide, alumina, yttria-stabilized zirconia, ceria-zirconia solid solution, and lanthanum oxide-zirconia solid solution are preferred, with titanium oxide, zirconium oxide, alumina, and cerium oxide being more preferred.

In addition to the solid catalysts described above, any solid acid catalyst may be added to the reaction system. Examples of such solid acid catalysts include zeolite, sulfate zirconia, montmorillonite, and mesoporous silica.

Solid catalysts may be prepared by known methods. There are no particular limitations on the method for supporting the metal on the catalyst support, but examples of applicable methods include deposition-precipitation, impregnation, and ion exchange.

[3] Raw Materials The propylene production method of this embodiment is characterized in that a raw material liquid containing glycerin and hydrogen are used as raw materials. Examples of the raw material liquid containing glycerin include industrial glycerin, glycerin reagent (e.g., a product of Fujifilm Wako Pure Chemical Industries, Ltd. that complies with JIS K8295), waste glycerin, or a mixture of these with a solvent. The raw material liquid containing glycerin preferably has a glycerin concentration of 10.0% by mass or more and 98.5% by mass or less and an alkali metal component concentration of 30% by mass or less. In this specification, the alkali metal component refers to sodium and potassium.

From the perspective of being environmentally friendly, it is preferable to use waste glycerin as the raw material liquid. In this embodiment, waste glycerin refers to a glycerin mixed liquid having a glycerin concentration of 10.0% by mass or more and 80.0% by mass or less, and an alkali metal component concentration of 0.5% by mass or more and 30% by mass or less. Although not particularly limited, it is preferable to use, for example, a glycerin mixed liquid produced as a by-product during the production of biodiesel from animal and vegetable oils.

Any vegetable or animal oil can be used as a raw material for producing biodiesel. Examples of such animal or vegetable oils include rapeseed oil, palm oil, olive oil, sunflower oil, soybean oil, rice oil, hemp oil, fish oil, lard, beef tallow, and waste cooking oil.

A mixture of waste glycerin and a solvent can also be used as the raw material liquid containing glycerin. In this case, from the viewpoint of eliminating the need for dealkalization treatment of the waste glycerin and achieving excellent energy efficiency, the alkali metal component is preferably at least 1 part by mass per 160 parts by mass of glycerin contained in the raw material liquid, more preferably at least 1 part by mass and no more than 480 parts by mass, even more preferably at least 1 part by mass and no more than 240 parts by mass, and particularly preferably at least 1 part by mass and no more than 80 parts by mass.

The content of alkali metal components in the raw material solution is measured using a calibration curve method using ion chromatography. The ion chromatograph used is, for example, the "IC-2000" manufactured by Tosoh Corporation.

The glycerin content in the raw material liquid is measured by gas chromatography (GC).

From the perspective of achieving excellent energy efficiency and environmental conservation during operation, the hydrogen addition pressure is preferably 0.1 to 5.0 MPaG at room temperature (e.g., 27°C), and more preferably 0.1 to 3.0 MPaG.

[4] Reaction Product In the propylene production method of this embodiment, a gas containing hydrocarbons such as propylene (hereinafter also referred to as recovered gas) can be obtained through the reaction step. From the viewpoint of excellent efficiency in separation and purification, the recovered gas preferably has a total proportion of propane and propylene among the hydrocarbons contained in the gas of 70 mass% or more, more preferably 80 mass% or more, and even more preferably 90 mass% or more. Among these, from the viewpoint of excellent efficiency in separation and purification, the selectivity of propylene relative to propane in the recovered gas (=recovered molar amount of propylene/(recovered molar amount of propane + recovered molar amount of propylene)) is preferably 30 mol% or more, more preferably 50 mol% or more, and even more preferably 80 mol% or more.

In this specification, hydrocarbons refer to compounds consisting only of carbon and hydrogen, and do not include compounds containing heteroatoms such as methanol.

[5] Reaction Conditions From the viewpoints of achieving an excellent reaction rate and excellent separability of the solid catalyst after the reaction, the amount of the solid catalyst used is, for example, preferably 5 to 1,000 parts by mass, more preferably 10 to 750 parts by mass, and even more preferably 10 to 500 parts by mass, per 100 parts by mass of glycerin.

The propylene production method of this embodiment is characterized by carrying out the reaction step in a liquid phase, so the reaction temperature is preferably below the boiling point of glycerin (290°C). For example, 100 to 290°C is preferred, 200 to 290°C is more preferred, and 240 to 270°C is even more preferred.

[6] Solvent In the propylene production method of this embodiment, purified glycerin, crude glycerin, waste glycerin, etc. may be diluted with a solvent and used as a raw material liquid. Examples of such solvents include water, hydrocarbon solvents (e.g., toluene, benzene, xylene, pentane, hexane, decane), ether solvents (e.g., tetrahydrofuran, dioxane, dimethoxyethane), alcohol solvents (ethylene glycol, ethanol, methanol, t-butanol), amide solvents (dimethylacetamide, acetamide, dimethylformamide, N-methylpyrrolidone), and halogen-based solvents (dichloroethane, dichloromethane, chloroform, carbon tetrachloride, trifluorotoluene).

The present invention will be explained in more detail below using examples, but the present invention is not limited to the examples described below.

(X-ray fluorescence analysis)
Apparatus: Rigaku Corporation, X-ray fluorescence analyzer (ZSX Primus II)
Method: Calibration curve method: The acac complex, chloride, or nitrate used in preparing each catalyst was used as a standard substance and mixed with the support used in preparing each catalyst to prepare a standard sample. X-ray fluorescence analysis was performed using the standard sample to create a calibration curve.
The standard samples for preparing the calibration curve were prepared so as to have a concentration range exceeding the upper limit of each catalyst described in the examples.

(Analysis of alkali metal components in raw materials)
Device: Tosoh "IC-2000"
Column: TSKGEL GUARD COLUMN SUPER IC-CR
Solution: 2.2 mM methanesulfonic acid + 1.0 mM 18-crown-6-ether Method: calibration curve method

(GC analysis of gas phase)
Equipment: Shimadzu GC-2010plus
Column SPB-1
Conditions: Injection temperature: 250°C, Detection temperature: 250°C
Carrier gas: nitrogen (column flow rate 0.46 ml/min, SP ratio 200)
Temperature increase rate: 40°C (held for 13 minutes) - (5°C/min) - 200°C

(GC analysis of liquid phase: quantitative analysis method for glycerin)
Equipment: Shimadzu GC-2010plus
Column DB-1
Conditions: Injection temperature: 300°C, Detection temperature: 300°C
Carrier gas: nitrogen (column flow rate 53.8 ml/min, SP ratio 25)
Temperature increase rate: 100°C (2 min hold) - (10°C/min) - 260°C (15 min
retention)
Internal standard: Anisole

[Example 1]
Preparation of waste glycerin: 900 g of rapeseed oil, 200 g of methanol, and 10 g of potassium hydroxide were added to a reactor and heated with stirring at 60°C for 1 hour. The reaction solution was allowed to stand and separated into two phases, and 150 g of the lower waste glycerin phase was recovered. The glycerin concentration in this waste glycerin was 63 mass %, and the alkali metal potassium concentration was 4 mass %.

Catalyst preparation: Palladium chloride and ammonium molybdate (VI) tetrahydrate were dissolved in aqueous ammonia, and then impregnated onto a zirconia support (RC-100, manufactured by Daiichi Kigenso Kagaku Kogyo Co., Ltd.). The resulting powder was calcined in air at 400°C for 4 hours to obtain 1.0% by mass Pd*2.0% by mass Mo/ _ZrO2 .

Reaction: 100 g of waste glycerin liquid and 5.0 g of 1.0 mass% Pd*2.0 mass% Mo/ _ZrO2 catalyst were added to a pressure-resistant reactor, and the reaction was carried out at 1.0 MPaG and 250°C for 2 hours. After the reaction, the reactor was cooled to room temperature, and the gas was recovered into a gas bag until the pressure inside the reactor reached atmospheric pressure. This process of adding 0.7 MPaG of nitrogen to the reactor and recovering it into a gas bag was repeated twice, and the gas produced by the reaction was recovered into a gas bag. GC analysis of the recovered gas confirmed that propylene was produced. The total proportion of propane and propylene in the hydrocarbons in the recovered gas was 99 mass% or more, and the selectivity of propylene to propane was 45 mol%. It was also confirmed that the total yield of propane and propylene was 30 mol% or more.

GC analysis of the reaction liquid (liquid phase) detected no compounds with carbon numbers of 3 or less other than methanol and glycerin contained in the raw materials. This indicates that 1.0 mass% Pd*2.0 mass% Mo/ _ZrO2 selectively produces gas components from glycerin even under the mild condition of hydrogen pressure of 1.0 MPaG.
When the catalyst composition before and after the reaction was compared by X-ray fluorescence analysis, it was found that the proportion of the alkaline component (potassium) contained in the waste glycerin did not increase. Therefore, it is true that carrying out the reaction step in a liquid phase can suppress the deposition of alkaline components on the catalyst.

[Example 2]
Catalyst preparation: Silver nitrate was dissolved in water and impregnated onto a cerium oxide support (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), followed by air calcination at 300°C for 2 hours. The resulting powder was dispersed in water, and ammonium perrhenate was added and impregnated. The resulting powder was then air calcined at 400°C for 4 hours to obtain 1.0% by mass Ag * 2.0% by mass Re/ _CeO2 .

Reaction: 100 g of waste glycerin liquid (glycerin 40% by mass, alkali metal concentration 2% by mass) and 10.0 g of 1.0% by mass Ag*2.0% by mass Re/ _CeO2 catalyst were added to a pressure-resistant reactor, and the reaction was carried out for 2 hours at 3.0 MPaG and 270°C under hydrogen pressure. After the reaction, GC analysis of the recovered gas confirmed that propylene was produced. The total proportion of propane and propylene in the hydrocarbons in the recovered gas was 99% by mass or more, and the selectivity of propylene to propane was 80% by mole. It was also confirmed that the total yield of propane and propylene was 30% by mole or more.

GC analysis of the reaction liquid (liquid phase) detected no compounds with three or fewer carbon atoms other than the methanol and glycerin contained in the raw materials. Furthermore, comparison of the catalyst composition before and after the reaction using X-ray fluorescence analysis revealed no increase in the proportion of alkaline components (potassium) contained in the waste glycerin.

[Example 3]
Catalyst preparation: Chloroauric acid tetrahydrate was dissolved in water and impregnated onto a cerium oxide support (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), followed by air calcination at 300°C for 2 hours. The resulting powder was dispersed in water, and ammonium perrhenate and ammonium molybdate (VI) tetrahydrate were added and impregnated. The resulting powder was then air calcined at 400°C for 4 hours to obtain 1.0 wt% Au * 2.0 wt% Re * 2.0 wt% Mo/ _CeO2 .

Reaction: 100 g of waste glycerin liquid (glycerin 61% by mass, alkali metal concentration 1% by mass) and 10.0 g of 1.0% by mass Au*2.0% by mass Re*2.0% by mass Mo/CeO2 catalyst were added to _a pressure reactor, and the reaction was carried out for 2 hours at 3.0 MPaG and 270°C under hydrogen pressure. After the reaction, GC analysis of the recovered gas confirmed that propylene was produced. The total proportion of propane and propylene in the hydrocarbons in the recovered gas was 99% by mass or more, and the selectivity of propylene to propane was 91% by mole. It was also confirmed that the total yield of propane and propylene was 30% by mole or more.

GC analysis of the reaction liquid (liquid phase) detected no compounds with three or fewer carbon atoms other than the methanol and glycerin contained in the raw materials. Furthermore, comparison of the catalyst composition before and after the reaction using X-ray fluorescence analysis revealed no increase in the proportion of alkaline components (potassium) contained in the waste glycerin.

[Example 4]
Catalyst preparation: Hexachloroiridate (IV) n-hydrate was dissolved in water and impregnated onto an alumina support (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), followed by air calcination at 300°C for 2 hours. The resulting powder was dispersed in water, and ammonium molybdate (VI) tetrahydrate was added and impregnated. The resulting powder was then air calcined at 400°C for 4 hours to obtain 1.0% by mass Ir*2.0% _by mass Mo/ _Al2O3 .

Reaction: 65 g of glycerin, 8 g of methanol, 7 g of water, 20 g of potassium oleate, and 5.0 g of _1.0 mass % Ir * 2.0 mass % Mo / _Al2O3 catalyst were added to a pressure-resistant reactor, and the reaction was carried out for 2 hours at 1.0 MPaG and 250 °C under hydrogen pressure. After the reaction, GC analysis of the recovered gas confirmed that propylene was produced. The total proportion of propane and propylene in the hydrocarbons in the recovered gas was 99 mass % or more, and the selectivity of propylene to propane was 30 mol %. It was also confirmed that the total yield of propane and propylene was 30 mol % or more.

GC analysis of the reaction liquid (liquid phase) detected no compounds with three or fewer carbon atoms other than the methanol and glycerin contained in the raw materials. Comparison of the catalyst composition before and after the reaction using X-ray fluorescence analysis revealed no increase in the proportion of alkaline components (potassium) contained in the glycerin raw material solution.

[Example 5]
Catalyst preparation: In the same manner as in Example 3, a 1.0 mass% Au*2.0 mass% Re*2.0 mass% Mo/ _CeO2 catalyst was obtained.

Reaction: 65 g of glycerin, 8 g of methanol, 7 g of water, 20 g of potassium oleate, and 10.0 g of a 1.0 mass% Au*2.0 mass% Re*2.0 mass% Mo/CeO2 catalyst were added to a pressure-resistant _reactor , and the reaction was carried out for 8 hours at 3.0 MPaG and 270°C under hydrogen pressure. After the reaction, GC analysis of the recovered gas confirmed that propylene was produced. The total proportion of propane and propylene in the hydrocarbons in the recovered gas was 99 mass% or more, and the selectivity of propylene to propane was 91 mol%. It was also confirmed that the total yield of propane and propylene was 30 mol% or more.

GC analysis of the reaction liquid (liquid phase) detected no compounds with three or fewer carbon atoms other than the methanol and glycerin contained in the raw materials. Comparison of the catalyst composition before and after the reaction using X-ray fluorescence analysis revealed no increase in the proportion of alkaline components (potassium) contained in the glycerin raw material solution.

[Example 6]
Catalyst preparation: Chloroplatinic acid n-hydrate was dissolved in water and impregnated onto an alumina support (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), followed by air calcination at 300°C for 2 hours. The resulting powder was dispersed in water, and sodium tungstate (VI) dihydrate was added and impregnated. The resulting powder was then air calcined at 400°C for 4 hours to obtain 1.0% by mass Pt*2.0 _% by mass W/ _Al2O3 .

Reaction: 65 g of glycerin, 8 g of methanol, 7 g of water, 20 g of potassium oleate, and 10.0 g of _1.0 mass % Pt*2.0 mass % W/ _Al2O3 catalyst were added to a pressure-resistant reactor, and the reaction was carried out for 2 hours at 1.0 MPaG and 250°C under hydrogen pressure. After the reaction, GC analysis of the recovered gas confirmed that propylene was produced. The total proportion of propane and propylene in the hydrocarbons in the recovered gas was 99 mass % or more, and the selectivity of propylene to propane was 40 mol %. It was also confirmed that the total yield of propane and propylene was 30 mol % or more.

GC analysis of the reaction liquid (liquid phase) detected no compounds with three or fewer carbon atoms other than the methanol and glycerin contained in the raw materials. Comparison of the catalyst composition before and after the reaction using X-ray fluorescence analysis revealed no increase in the proportion of alkaline components (potassium) contained in the glycerin raw material solution.

[Example 7]
Catalyst preparation: Hexachloroiridium (IV) acid n-hydrate was dissolved in water, and the solution was impregnated onto an alumina carrier (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) and calcined in air at 300°C for 2 hours to obtain 1.0 _mass % Ir/ _Al2O3 .

Reaction: 65 g of glycerin, 8 g of methanol, 7 g of water, 20 g of potassium oleate, and 10.0 g of _1.0 mass % Ir/ _Al2O3 catalyst were added to a pressure reactor, and the reaction was carried out for 2 hours at 1.0 MPaG and 250°C under hydrogen pressure. After the reaction, GC analysis of the recovered gas confirmed that propylene was produced. The total proportion of propane and propylene in the hydrocarbons in the recovered gas was 99 mass % or more, and the selectivity of propylene to propane was 33 mol %. It was also confirmed that the total yield of propane and propylene was 30 mol % or more.

GC analysis of the reaction liquid (liquid phase) detected no compounds with three or fewer carbon atoms other than the methanol and glycerin contained in the raw materials. Comparison of the catalyst composition before and after the reaction using X-ray fluorescence analysis revealed no increase in the proportion of alkaline components (potassium) contained in the glycerin raw material solution.

[Example 8]
Catalyst preparation: Silver nitrate was dissolved in water and impregnated onto a cerium oxide support (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) and calcined in air at 300°C for 2 hours. The resulting powder was dispersed in water, and ammonium molybdate (VI) tetrahydrate was added and impregnated. The resulting powder was then calcined in air at 400°C for 4 hours to obtain 1.0% by mass Ag * 2.0% by mass Mo/ _CeO2 .

Reaction: 80 g of glycerin, 20 g of water, and 10.0 g of a 1.0 mass% Ag*2.0 mass% Mo/ _CeO2 catalyst were added to a pressure-resistant reactor, and the reaction was carried out for 8 hours at 1.0 MPaG and 250°C under hydrogen pressure. After the reaction, GC analysis of the recovered gas confirmed that propylene was produced. The total proportion of propane and propylene in the hydrocarbons in the recovered gas was 99 mass% or more, and the selectivity of propylene to propane was 83 mol%. It was also confirmed that the total yield of propane and propylene was 30 mol% or more.

GC analysis of the reaction liquid (liquid phase) revealed that no compounds with carbon numbers of 3 or less were detected other than the methanol and glycerin contained in the raw materials.

[Example 9]
Catalyst preparation: Rhodium (III) chloride trihydrate was dissolved in water and impregnated onto a cerium oxide support (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) and calcined in air at 300°C for 2 hours. The resulting powder was dispersed in water, and ammonium perrhenate was added and impregnated. The resulting powder was then calcined in air at 400°C for 4 hours to obtain 1.0% by mass Rh*2.0% by mass Re/ _CeO2 .

Reaction: 80 g of glycerin, 20 g of water, and 5.0 g of a 1.0 mass% Rh*2.0 mass% Re/ _CeO2 catalyst were added to a pressure-resistant reactor, and the reaction was carried out for 2 hours at 1.0 MPaG and 250°C under hydrogen pressure. After the reaction, GC analysis of the recovered gas confirmed that propylene was produced. The total proportion of propane and propylene in the hydrocarbons in the recovered gas was 99 mass% or more, and the selectivity of propylene relative to propane was 31 mol%. It was also confirmed that the total yield of propane and propylene was 30 mol% or more.

GC analysis of the reaction liquid (liquid phase) revealed that no compounds with carbon numbers of 3 or less were detected other than the methanol and glycerin contained in the raw materials.

[Example 10]
Catalyst preparation: Hexachloroiridate (IV) n-hydrate was dissolved in water and impregnated onto a cerium oxide support (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) and calcined in air at 300°C for 2 hours. The resulting powder was dispersed in water, and sodium metavanadate was added and impregnated. The resulting powder was then calcined in air at 400°C for 4 hours to obtain 1.0% Ir by mass * 2.0% V by mass / _CeO2 .

Reaction: 100 g of glycerin and 5.0 g of a 1.0 mass % Ir*2.0 mass % V/ _CeO2 catalyst were added to a pressure-resistant reactor, and the reaction was carried out for 2 hours at 1.0 MPaG and 250°C under hydrogen pressure. After the reaction, GC analysis of the recovered gas confirmed that propylene was produced. The total proportion of propane and propylene in the hydrocarbons in the recovered gas was 99 mass % or more, and the selectivity of propylene relative to propane was 32 mol %. It was also confirmed that the total yield of propane and propylene was 30 mol % or more.

GC analysis of the reaction liquid (liquid phase) revealed that no compounds with carbon numbers of 3 or less were detected other than the methanol and glycerin contained in the raw materials.

[Example 11]
Catalyst preparation: 1.0 mass % Ir/Al ₂ O ₃ was obtained in the same manner as in Example 7.

Reaction: 80 g of glycerin, 20 g of water, 5.0 g of _1.0 mass % Ir/ _Al2O3 catalyst, and 5.0 g of HSZ-5 catalyst were placed in a pressure reactor, and the reaction was carried out for 2 hours at 1.0 MPaG hydrogen and 250°C. After the reaction, GC analysis of the recovered gas confirmed that propylene was produced. The total proportion of propane and propylene in the hydrocarbons in the recovered gas was 99 mass % or more, and the selectivity of propylene relative to propane was 32 mol %. It was also confirmed that the total yield of propane and propylene was 30 mol % or more.

GC analysis of the reaction liquid (liquid phase) revealed that no compounds with carbon numbers of 3 or less were detected other than the methanol and glycerin contained in the raw materials.

Claims (7)

A method for producing propylene , comprising a step of reacting a raw material liquid containing glycerin, which is a by-product in the production of biodiesel, with hydrogen in a liquid phase in the presence of a solid catalyst containing one or more first metal elements selected from the group consisting of silver and gold, and one or more second metal elements selected from the group consisting of tungsten, molybdenum, rhenium, and vanadium. The manufacturing method described in claim 1, wherein the raw material liquid contains 10.0% by mass or more and 98.5% by mass or less of glycerin and 30% by mass or less of an alkali metal component. The manufacturing method described in claim 1 or 2, wherein the raw material liquid contains 10.0% by mass or more and 80.0% by mass or less of glycerin and 0.5% by mass or more and 30% by mass or less of an alkali metal component. The manufacturing method described in any one of claims 1 to 3, wherein the raw material solution contains an alkali metal component, and the amount of the alkali metal component is 1 part by mass or more per 160 parts by mass of the glycerin. 5. The production method according to claim 1 , wherein the reaction produces a gas containing hydrocarbons, and the hydrocarbons contain propylene and propane in a total amount of 70 mass % or more. The method according to claim 5 , wherein the ratio of the number of moles of propylene to the total number of moles of propylene and propane is 30 mol% or more. 7. The method according to claim 1 , wherein the hydrogen addition pressure is 0.1 MPaG or more and 5.0 MPaG or less at room temperature.