Method for producing ethylene and propylene

Abstract

A method for producing ethylene and propylene comprises: a reaction step (1) for bringing a raw material (1a) containing ethanol into contact with a catalyst to obtain a product (1b) containing ethylene and propylene; a gas-liquid separation step (2) for separating the product (1b) into a gas component (2a) containing ethylene and propylene and a liquid component (2b) containing acetone; a gas separation step (3) for separating carbon dioxide (3a), water (3b), and hydrogen (3c) from the gas component (2a) to obtain a gas component (3d) containing ethylene and propylene; and an olefin separation step (4) for separating the gas component (3d) into a low-boiling fraction (4a), ethylene (4b), propylene (4c), and a high-boiling fraction (4d).

Description

Method for producing ethylene and propylene CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority from Japanese Patent Application Nos. 2024-69203 and 2025-45973, the disclosures of which are incorporated herein by reference.

[0002] The present invention relates to a method for producing ethylene and propylene using ethanol as a raw material.

[0003] Ethylene and propylene, which are lower olefins, are key raw materials in the chemical industry and have traditionally been produced from petroleum as a raw material by, for example, petroleum refining, naphtha cracking, and the like.

[0004] Recently, due to growing interest in climate change issues and increased awareness of environmental conservation, there is a demand for technologies to produce lower olefins from raw materials with low environmental impact and sustainable raw materials. For example, technologies to produce lower olefins using methanol or ethanol produced from biomass raw materials, waste, etc. as raw materials are attracting attention.

[0005] For example, Patent Documents 1 and 2 disclose zirconium oxide catalysts as catalysts for producing propylene from ethanol, and Patent Documents 3 and 4 disclose methods for producing ethylene and propylene from ethanol using zirconium oxide catalysts.

[0006] Japanese Patent Publication No. 2012-254447 Japanese Patent Publication No. 2023-96890 Japanese Patent Publication No. 2016-150932 International Publication No. 2022 / 168695

[0007] In the above-mentioned conventional methods for producing ethylene and propylene using ethanol as a raw material, productivity, including production efficiency of ethylene and propylene and operational stability of the production process, has not necessarily been sufficient.

[0008] Under these circumstances, the problem to be solved by the present invention is to provide a method for producing ethylene and propylene with excellent productivity using ethanol as a raw material.

[0009] The present invention is as follows: <1> A method for producing ethylene and propylene, comprising: a reaction step (1) of contacting a raw material (1a) containing ethanol with a catalyst to obtain a product (1b) containing ethylene and propylene; a gas-liquid separation step (2) of separating the product (1b) obtained in the reaction step (1) into a gas component (2a) containing ethylene and propylene and a liquid component (2b) containing acetone; a gas separation step (3) of separating carbon dioxide (3a), water (3b), and hydrogen (3c) from the gas component (2a) obtained in the gas-liquid separation step (2) to obtain a gas component (3d) containing ethylene and propylene; and an olefin separation step (4) of separating the gas component (3d) containing ethylene and propylene obtained in the gas separation step (3) into a light-boiling fraction (4a), ethylene (4b), propylene (4c), and a high-boiling fraction (4d).

[0010] FIG. 1 is a process flow diagram showing a method for producing ethylene and propylene according to an embodiment of the present invention. FIG. 2 is a process flow diagram showing a first aspect of the gas separation step (3) according to an embodiment of the present invention. FIG. 3 is a process flow diagram showing a second aspect of the gas separation step (3) according to an embodiment of the present invention. FIG. 4 is a process flow diagram showing a fourth aspect of the gas separation step (3) according to an embodiment of the present invention. FIG. 5 is a process flow diagram showing the methanol synthesis step (5) according to an embodiment of the present invention. FIG. 6 is a process flow diagram showing the methane synthesis step (5') according to an embodiment of the present invention. FIG. 7 is a process flow diagram showing the acetone / water separation step (6) and the recycle step (7) according to an embodiment of the present invention. FIG. 8 is a process flow diagram showing the water supply step (8) according to an embodiment of the present invention. FIG. 9 is a process flow diagram showing the methanol synthesis step (5), the acetone / water separation step (6), the recycle step (7), and the water supply step (8) according to an embodiment of the present invention. FIG. 10 is a process flow diagram showing a first distillation method for the olefin separation step (4) according to an embodiment of the present invention. FIG. 11 is a process flow diagram showing a second distillation method for the olefin separation step (4) according to an embodiment of the present invention. FIG. 12 is a process flow diagram showing a third distillation method for the olefin separation step (4) according to an embodiment of the present invention. 1 is a process flow diagram showing a fourth distillation method in the olefin separation step (4) according to an embodiment of the present invention. FIG. 2 is a process flow diagram showing a fifth distillation method in the olefin separation step (4) according to an embodiment of the present invention.

[0011] The method for producing ethylene and propylene according to an embodiment of the present invention will be described below. As shown in Figure 1, the method for producing ethylene and propylene according to an embodiment of the present invention includes a reaction step (1), a gas-liquid separation step (2), a gas separation step (3), and an olefin separation step (4).

[0012] [Reaction Step (1)] The method for producing ethylene and propylene according to this embodiment includes a reaction step (1) in which a raw material (1a) containing ethanol is contacted with a catalyst to obtain a product (1b) containing ethylene and propylene. The raw material (1a) may further contain at least one compound selected from the group of oxygen-containing compounds consisting of water, acetone, acetaldehyde, and isopropanol.

[0013] The ethanol contained in the raw material (1a) is not particularly limited, and examples thereof include biomass-derived ethanol, ethanol produced from carbon dioxide and hydrogen as raw materials, ethanol produced by the hydration reaction of ethylene, etc. These ethanols can be used alone or in combination of two or more.

[0014] Examples of carbon oxides that can be used as raw materials for ethanol include carbon oxides produced by decomposing biomass, carbon oxides produced from fossil fuels, carbon oxides generated in the process of using fossil resources as energy, carbon oxides generated in the process of manufacturing steel or chemical products, carbon oxides produced using plastics as raw materials, and carbon dioxide recovered from the air. These carbon oxides can be used alone or in combination of two or more. Examples of hydrogen that can be used as raw materials for ethanol include hydrogen derived from fossil fuels, hydrogen produced by decomposing ammonia, and hydrogen produced by electrolysis of water.

[0015] From the viewpoint of further increasing the yield of propylene in the product (1b), the raw material (1a) preferably contains water. The molar ratio of water to ethanol in the raw material (1a) (water (mol) / ethanol (mol)) is preferably 0.1 or more, more preferably 0.2 or more, and even more preferably 0.3 or more. The molar ratio of water to ethanol in the raw material (1a) is preferably 10 or less, more preferably 8 or less, and even more preferably 5 or less.

[0016] The catalyst may be any catalyst capable of synthesizing ethylene and propylene from ethanol, such as a zirconium oxide catalyst, an indium oxide catalyst, a cerium oxide catalyst, an aluminum oxide catalyst, or a zeolite catalyst. The catalyst is preferably a zirconium oxide catalyst, and more preferably a zirconium oxide catalyst further containing at least one element (M) selected from the group consisting of metals of Group 1 and Group 2 elements of the IUPAC Periodic Table of the Elements (2022), scandium, yttrium, cerium, titanium, vanadium, chromium, copper, silver, gallium, germanium, manganese, lanthanum, neodymium, and tin. The element (M) is preferably at least one element selected from the group consisting of lithium, sodium, potassium, magnesium, calcium, strontium, barium, scandium, yttrium, and cerium, more preferably at least one of calcium and yttrium, and even more preferably calcium. The element (M) may be contained in the zirconium oxide catalyst as a simple element, or as an oxide, hydroxide, salt, or alkoxide of the element. Examples of the salt include inorganic salts such as nitrates, sulfates, phosphates, hydrochlorides, and carbonates, and organic salts such as carboxylates, sulfonates, and organic phosphates.

[0017] The content of the element (M) in the catalyst is preferably more than 0 mass % and not more than 50 mass %, with the total of zirconium oxide and the element (M) being 100 mass %.

[0018] As the catalyst, for example, JP 2012-120978 A, JP 2012-136516 A, JP 2013-252495 A, JP 2013-254447 A, JP 2016-150932 A, WO 2022 / 168695, WO 2022 / 226371, JP 2023-96890 A catalyst described in can be used.

[0019] The reaction step (1) may be carried out using a reactor. Examples of reactors that can be used include fixed-bed reactors, moving-bed reactors, fluidized-bed reactors, batch reactors, and semi-batch reactors. The reactor may be an adiabatic reactor, an isothermal reactor, or a heat exchange reactor. The reactor may be a single-stage reactor or a multi-stage reactor equipped with a plurality of reactors. When the reactor is a multi-stage reactor, a heating device may be installed between each reactor. The reactor is preferably an adiabatic reactor such as a fixed-bed adiabatic reactor, a moving-bed adiabatic reactor, or a fluidized-bed adiabatic reactor, and more preferably a fixed-bed adiabatic reactor.

[0020] In the method for contacting the raw material (1a) with the catalyst, it is sufficient that the raw material (1a) can be contacted with the catalyst in a gaseous or liquid state. From the viewpoint of further increasing the yield of propylene in the product (1b), the method for contacting the raw material (1a) with the catalyst is preferably a method in which the raw material (1a) gasified by heating is supplied to a reactor pre-filled with a catalyst, and the gasified raw material (1a) is contacted with the catalyst. The gasified raw material (1a) may be supplied to the reactor in combination with other gas components, such as nitrogen, hydrogen, carbon monoxide, carbon dioxide, etc.

[0021] The reaction temperature in the reaction step (1) is preferably 270°C to 700°C, more preferably 300°C to 650°C, and even more preferably 350°C to 550°C. When a reactor is used in the reaction step (1), the reaction temperature may be the temperature of the steam containing the raw material (1a) or the catalyst inside the reactor. The reactor may be equipped with a thermometer inside the reactor for measuring the temperature of the steam or the catalyst inside the reactor.

[0022] The reaction pressure in the reaction step (1) is preferably 10 kPaA to 10,000 kPaA, more preferably 100 kPaA to 5,000 kPaA.

[0023] [Raw Material Treatment Step] From the viewpoint of suppressing side reactions, the method for producing ethylene and propylene according to this embodiment may include a raw material treatment step in which the raw material (1a) is brought into contact with an acid adsorbent before being supplied to the reaction step (1). Examples of the acid adsorbent include (a) microporous aluminosilicate, (b) macroporous resin grafted with an acid group (e.g., sulfonic acid), (c) strongly acidic ion exchange resin, (d) silica impregnated with an acid (e.g., phosphoric acid, sulfuric acid), (e) activated carbon, (f) activated alumina, (g) clay, (h) molecular sieve, and (i) crystalline microporous aluminophosphate.

[0024] [Gas-Liquid Separation Step (2)] The method for producing ethylene and propylene according to this embodiment includes a gas-liquid separation step (2) for separating the product (1b) obtained in the reaction step (1) into a gas component (2a) containing ethylene and propylene and a liquid component (2b) containing acetone. The gas-liquid separation step (2) may be any method capable of separating the majority of ethylene and propylene contained in the product (1b) into a gas phase and the majority of acetone contained in the product (1b) into a liquid phase.

[0025] Examples of methods for separating the majority of ethylene and propylene contained in the product (1b) into a gas phase and the majority of acetone into a liquid phase include a method of separating the product (1b) by pressurizing or cooling the product (1b). In the gas-liquid separation step (2), the product (1b) is cooled by a known cooling method using, for example, a tubular heat exchanger, an air fin cooler, or the like to form a gas component (2a) containing ethylene and propylene and a liquid component (2b) containing acetone, and the gas component (2a) and the liquid component (2b) are separated using a packed tower. For example, a countercurrent packed tower is used as the packed tower. The gas component (2a) and the liquid component (2b) are supplied to the bottom of the packed tower. An absorbing fluid (e.g., water) is added dropwise from the top of the packed tower. The gas component (2a) rises in the packed tower while contacting the absorbing fluid and is discharged from the top. The liquid component (2b) containing the absorbing fluid is withdrawn from the bottom of the packed tower. Furthermore, a method for separating most of the ethylene and propylene contained in the product (1b) into a gas phase and most of the acetone into a liquid phase may be performed by supplying the high-temperature gas of the product (1b) to a packed column, and cooling, liquefying, absorbing and separating, for example, acetone, etc., with the absorbing fluid in the packed column.

[0026] [Gas Separation Step (3)] The method for producing ethylene and propylene according to this embodiment includes a gas separation step (3) in which carbon dioxide (3a), water (3b), and hydrogen (3c) are separated from the gas component (2a) obtained in the gas-liquid separation step (2) to obtain a gas component (3d) containing ethylene and propylene.

[0027] Methods for separating carbon dioxide (3a) from gas component (2a) include, for example, chemical absorption, physical absorption, solid adsorption, solid absorption, membrane separation, etc. Two or more of these may be used in combination. Note that chemical absorption, physical absorption, and solid absorption may be collectively referred to as absorption methods.

[0028] The chemical absorption method is a method for separating and recovering carbon dioxide that utilizes a chemical reaction between carbon dioxide and an absorbing solution. Examples of absorbing solutions include amine compounds such as monoethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, monoisopropanolamine, diisopropanolamine, diglycolamine, 2-isopropylaminoethanol, and piperazine. Examples of methods for recovering carbon dioxide include heating an absorbing solution containing carbon dioxide to 110 to 130°C to dissociate the carbon dioxide from the absorbing solution, cooling the gas containing the dissociated carbon dioxide to condense the water in the gas, and separating the condensed water from the gas. Carbon dioxide separation by chemical absorption may also be performed multiple times using one or more absorbing solutions.

[0029] The physical absorption method is a method for separating and recovering carbon dioxide by dissolving carbon dioxide in an absorbing liquid. Examples of the absorbing liquid include N-methylpyrrolidone, methanol, a dimethyl ether solution of polyethylene glycol, and polypropylene carbonate. Methods for recovering carbon dioxide include reducing the pressure or heating the absorbing liquid containing carbon dioxide to separate the carbon dioxide from the absorbing liquid. Furthermore, separation of carbon dioxide by physical absorption may be carried out multiple times using one or more types of absorbing liquid.

[0030] The solid adsorption method is a method for separating and recovering carbon dioxide that utilizes the pressure-temperature dependence of the amount of carbon dioxide adsorbed onto a solid adsorbent. Examples of adsorbents include zeolite and activated carbon. One method for recovering carbon dioxide is to desorb carbon dioxide from a solid adsorbent by reducing the pressure or heating the adsorbent. Carbon dioxide separation by the solid adsorption method may be performed multiple times using one or more adsorbents.

[0031] The solid absorption method is a method for separating and recovering carbon dioxide using a solid absorbent. Examples of solid absorbents include those in which an amine compound used as an absorption liquid in chemical absorption is supported on or coated on a support. Examples of supports include organic materials such as polymethyl methacrylate beads and styrene beads, silica, alumina, clay minerals, silica alumina, magnesia, zirconia, lithium silicate, and mixtures thereof. Examples of methods for recovering carbon dioxide include heating or steam-treating a solid absorbent that has absorbed carbon dioxide to desorb the carbon dioxide from the solid absorbent, cooling the desorbed gas to condense the water in the gas, and separating the condensed water from the gas. Carbon dioxide separation by the solid absorption method may also be performed multiple times using one or more solid absorbents.

[0032] Membrane separation is a method for separating and capturing carbon dioxide using a carbon dioxide separation membrane with a carbon dioxide separation function. Examples of separation membranes include zeolite-based separation membranes, ceramic-based separation membranes, polyamide-amine-based separation membranes, aromatic polyimide-based separation membranes, and siloxane-based separation membranes. Examples of carbon dioxide separation membranes include those described in JP 2008-36463 A, JP 2012-232274 A, WO 2013 / 180218 A, WO 2019 / 131786 A, WO 2018 / 211945 A, JP 2017-176989 A, and JP 2016-163871 A. Carbon dioxide separation by membrane separation may be performed multiple times using one or more types of separation membranes.

[0033] Examples of methods for separating water (3b) include a method in which water is condensed by compression and / or cooling and then the condensed water is separated, an adsorption method, etc. The method for separating water (3b) may be a combination of two or more of these methods, and is preferably a method in which water is condensed by compression and cooling and then the condensed water is separated (compression / cooling separation method), and then water is separated by an adsorption method.

[0034] Examples of a method for condensing water by compression and / or cooling and separating the condensed water include a method in which gas at about 0.01 MPaG is compressed to 0.5 MPaG to 3 MPaG using a gas compressor, the compressed gas is cooled to 40°C or less to condense the water, and the condensed water is separated using a gas-liquid separator.

[0035] The adsorption method is a method of adsorbing water onto an adsorbent. Examples of adsorbents include synthetic zeolite, silica gel, activated alumina, etc. The adsorption method usually includes an adsorption step in which a packed tower is filled with the adsorbent and a gas is passed through the packed tower to adsorb water in the gas onto the adsorbent. A method for regenerating a water-adsorbed adsorbent includes passing a heated gas through the packed tower to desorb water from the adsorbent (also referred to as a regeneration step). When a packed tower is used, the adsorption method preferably involves filling two or more packed towers with the adsorbent, performing the adsorption step in at least one packed tower, and performing the regeneration step of the packing in at least one packed tower. The regeneration step preferably includes a step of compressing and cooling the desorbed water-containing gas discharged from the packed tower to condense the desorbed water and separate the condensed water. In addition, water separation by the adsorption method may be performed multiple times using one or more adsorbents.

[0036] Examples of methods for separating hydrogen (3c) include membrane separation, adsorption, cryogenic recovery, etc. Two or more of these methods may be combined to separate hydrogen (3c).

[0037] Membrane separation is a method for separating and recovering hydrogen using a hydrogen separation membrane with a hydrogen separation function. Examples of such membranes include palladium alloy separation membranes, polyamide separation membranes, zeolite separation membranes, and ceramic separation membranes. Examples of hydrogen separation methods include those described in JP 2016-59902 A, WO 2019 / 131786 A, and WO 2022 / 030572 A. Hydrogen separation by membrane separation may be performed multiple times using one or more types of separation membranes.

[0038] The adsorption method is a method for separating and recovering hydrogen that utilizes the pressure and temperature dependence of the amount of hydrogen adsorbed onto an adsorbent. Examples of adsorption methods include pressure swing adsorption, and examples of adsorbents include activated carbon and carbon molecular sieves. One method for recovering hydrogen using pressure swing adsorption involves decompressing a solid adsorbent to desorb hydrogen from the adsorbent. Furthermore, hydrogen separation using the adsorption method may be performed multiple times using one or more adsorbents.

[0039] The cryogenic recovery method is a method of increasing the concentration of hydrogen by cooling the gas and condensing most of the components other than hydrogen. Typically, the gas is cooled in a heat exchanger, and the condensed liquid is separated in a gas-liquid separator to extract hydrogen.

[0040] In the gas separation step (3), carbon dioxide (3a) may be separated multiple times, water (3b) may be separated multiple times, or hydrogen (3c) may be separated multiple times. In addition, carbon dioxide (3a) and water (3b) may be separated simultaneously in the gas separation step (3), in which case carbon dioxide (3a) and water (3b) may be separated multiple times. In the gas separation step (3), water (3b) and hydrogen (3c) may be separated simultaneously in which case water (3b) and hydrogen (3c) may be separated multiple times. In the gas separation step (3), carbon dioxide (3a) and hydrogen (3c) may be separated simultaneously in which case carbon dioxide (3a) and hydrogen (3c) may be separated multiple times. In the gas separation step (3), carbon dioxide (3a), water (3b), and hydrogen (3c) may be separated simultaneously, and in this case, carbon dioxide (3a), water (3b), and hydrogen (3c) may be separated multiple times. Furthermore, these separations may be performed in any order.

[0041] 2 , in a first embodiment, the gas separation step (3) may separate carbon dioxide (3a) from the gas component (2a), then water (3b), and then hydrogen (3c). From the viewpoint of obtaining better productivity, the ethylene and propylene production method according to this embodiment has, as a first embodiment, the gas separation step (3) including a carbon dioxide separation step (3-1) for separating carbon dioxide (3a) from the gas component (2a) obtained in the gas-liquid separation step (2) to obtain a gas component (3e), a water separation step (3-2) for separating water (3b) from the gas component (3e) obtained in the carbon dioxide separation step (3-1) to obtain a gas component (3f), and a hydrogen separation step (3-3) for separating hydrogen (3c) from the gas component (3f) obtained in the water separation step (3-2) to obtain a gas component (3d) containing ethylene and propylene.

[0042] 3 , in a second aspect of the gas separation step (3), carbon dioxide (3a) and hydrogen (3c) may be separated from the gas component (2a), and then water (3b) may be separated. From the viewpoint of obtaining better productivity, the ethylene and propylene production method according to this embodiment has, as a second aspect, the gas separation step (3) including a carbon dioxide / hydrogen separation step (3-4) in which carbon dioxide (3a) and hydrogen (3c) are separated from the gas component (2a) obtained in the gas-liquid separation step (2) to obtain a gas component (3g), and a water separation step (3-5) in which water (3b) is separated from the gas component (3g) obtained in the carbon dioxide / hydrogen separation step (3-4) to obtain a gas component (3d) containing ethylene and propylene.

[0043] In the carbon dioxide / hydrogen separation step (3-4), carbon dioxide (3a) and hydrogen (3c) may be simultaneously separated from the gas component (2a), and then the mixture of carbon dioxide (3a) and hydrogen (3c) may be separated into carbon dioxide (3a) and hydrogen (3c), or carbon dioxide (3a) may be separated from the gas component (2a) and then hydrogen (3c) may be separated, or hydrogen (3c) may be separated from the gas component (2a) and then carbon dioxide (3a). Furthermore, at least one of the separation of carbon dioxide (3a) and the separation of hydrogen (3c) may be performed multiple times, and in this case, the separation of carbon dioxide (3a) and the separation of hydrogen (3c) may be performed alternately.

[0044] 4, in a third aspect of the gas separation step (3), water (3b) may be separated from gas component (2a), followed by separation of carbon dioxide (3a) and hydrogen (3c). From the viewpoint of obtaining better productivity, the method for producing ethylene and propylene according to this embodiment has, as a third aspect, the gas separation step (3), which includes a water separation step (3-6) in which water (3b) is separated from the gas component (2a) obtained in the gas-liquid separation step (2) to obtain gas component (3h), and a carbon dioxide / hydrogen separation step (3-7) in which carbon dioxide (3a) and hydrogen (3c) are separated from the gas component (3h) obtained in the water separation step (3-6) to obtain gas component (3d) containing ethylene and propylene.

[0045] In the carbon dioxide / hydrogen separation step (3-7), carbon dioxide (3a) and hydrogen (3c) may be simultaneously separated from the gas component (3h), and then the mixture of carbon dioxide (3a) and hydrogen (3c) may be separated into carbon dioxide (3a) and hydrogen (3c), or carbon dioxide (3a) may be separated from the gas component (3h) and then hydrogen (3c) may be separated, or hydrogen (3c) may be separated from the gas component (3h) and then carbon dioxide (3a) may be separated. Also, at least one of the separation of carbon dioxide (3a) and the separation of hydrogen (3c) may be performed multiple times, and in this case, the separation of carbon dioxide (3a) and the separation of hydrogen (3c) may be performed alternately.

[0046] 5, in a fourth aspect of the gas separation step (3), hydrogen (3c) may be separated from the gas component (2a), followed by separation of water (3b), and then separation of carbon dioxide (3a). From the viewpoint of obtaining better productivity, the method for producing ethylene and propylene according to this embodiment has, as a fourth aspect, the gas separation step (3) including a hydrogen separation step (3-8) in which hydrogen (3c) is separated from the gas component (2a) obtained in the gas-liquid separation step (2) to obtain a gas component (3i), a water separation step (3-9) in which water (3b) is separated from the gas component (3i) obtained in the hydrogen separation step (3-8) to obtain a gas component (3j), and a carbon dioxide separation step (3-10) in which carbon dioxide (3a) is separated from the gas component (3j) obtained in the water separation step (3-9) to obtain a gas component (3d) containing ethylene and propylene.

[0047] From the viewpoint of obtaining better productivity, in the method for producing ethylene and propylene according to this embodiment, the water separation step (3-2), (3-5), (3-6), or (3-9) may include a condensation step of condensing water by compression and cooling, and an adsorption step of separating the water generated in the condensation step by an adsorption method. As the water separation step (3-2), (3-5), (3-6), or (3-9), a step of performing water separation by a compression / cooling separation method and then performing water separation by an adsorption method is preferred.

[0048] More specifically, the gas separation process (3) can include the following processes: (1) A carbon dioxide separation process by absorption, a water separation process by compression and cooling separation, a water separation process by adsorption, and a hydrogen separation process by membrane separation, arranged in this order. (2) A carbon dioxide separation process by absorption, a water separation process by compression and cooling separation, a water separation process by adsorption, and a hydrogen separation process by adsorption, arranged in this order. (3) A carbon dioxide separation process by solid adsorption, a water separation process by compression and cooling separation, a water separation process by adsorption, and a hydrogen separation process by membrane separation, arranged in this order. (4) A carbon dioxide separation process by solid adsorption, a water separation process by compression and cooling separation, a water separation process by adsorption, and a hydrogen separation process by adsorption, arranged in this order. (5) A carbon dioxide separation process by membrane separation, a water separation process by compression and cooling separation, a water separation process by adsorption, and a hydrogen separation process by membrane separation, arranged in this order. (6) A carbon dioxide separation process by membrane separation, a water separation process by compression and cooling separation, a water separation process by adsorption, and a hydrogen separation process by adsorption, arranged in this order.

[0049] (7) A carbon dioxide / hydrogen separation process using a membrane separation method, a water separation process using a compression / cooling separation method, and a water separation process using an adsorption method are arranged in this order. (8) A carbon dioxide separation process using a membrane separation method, a hydrogen separation process using an adsorption method, a water separation process using a compression / cooling separation method, and a water separation process using an adsorption method are arranged in this order. (9) A carbon dioxide separation process using an absorption method, a hydrogen separation process using a membrane separation method, a water separation process using a compression / cooling separation method, and a water separation process using an adsorption method are arranged in this order. (10) A carbon dioxide separation process using an absorption method, a hydrogen separation process using an adsorption method, a water separation process using a compression / cooling separation method, and a water separation process using an adsorption method are arranged in this order. (11) A carbon dioxide separation process using a solid adsorption method, a hydrogen separation process using a membrane separation method, a water separation process using a compression / cooling separation method, and a water separation process using an adsorption method are arranged in this order. (12) A carbon dioxide separation process using a solid adsorption method, a hydrogen separation process using an adsorption method, a water separation process using a compression / cooling separation method, and a water separation process using an adsorption method are arranged in this order. (13) A hydrogen separation process by adsorption, a carbon dioxide separation process by membrane separation, a water separation process by compression and cooling separation, and a water separation process by adsorption are arranged in this order. (14) A hydrogen separation process by membrane separation, a carbon dioxide separation process by absorption, a water separation process by compression and cooling separation, and a water separation process by adsorption are arranged in this order. (15) A hydrogen separation process by adsorption, a carbon dioxide separation process by absorption, a water separation process by compression and cooling separation, and a water separation process by adsorption are arranged in this order. (16) A hydrogen separation process by membrane separation, a carbon dioxide separation process by solid adsorption, a water separation process by compression and cooling separation, and a water separation process by adsorption are arranged in this order. (17) A hydrogen separation process by adsorption, a carbon dioxide separation process by solid adsorption, a water separation process by compression and cooling separation, and a water separation process by adsorption are arranged in this order.

[0050] (18) A water separation process by a compression-cooling separation method, a water separation process by an adsorption method, and a carbon dioxide / hydrogen separation process by a membrane separation method are arranged in this order. (19) A water separation process by a compression-cooling separation method, a water separation process by an adsorption method, a carbon dioxide separation process by a membrane separation method, and a hydrogen separation process by an adsorption method are arranged in this order. (20) A water separation process by a compression-cooling separation method, a water separation process by an adsorption method, a carbon dioxide separation process by an adsorption method, and a hydrogen separation process by a membrane separation method are arranged in this order. (21) A water separation process by a compression-cooling separation method, a water separation process by an adsorption method, a carbon dioxide separation process by an adsorption method, and a hydrogen separation process by an adsorption method are arranged in this order. (22) A water separation process by a compression-cooling separation method, a water separation process by an adsorption method, a carbon dioxide separation process by a solid adsorption method, and a hydrogen separation process by a membrane separation method are arranged in this order. (23) A water separation process by a compression-cooling separation method, a water separation process by an adsorption method, a carbon dioxide separation process by a solid adsorption method, and a hydrogen separation process by an adsorption method are arranged in this order. (24) A water separation process by a compression and cooling separation method, a water separation process by an adsorption method, a hydrogen separation process by an adsorption method, and a carbon dioxide separation process by a membrane separation method are arranged in this order. (25) A water separation process by a compression and cooling separation method, a water separation process by an adsorption method, a hydrogen separation process by a membrane separation method, and a carbon dioxide separation process by an absorption method are arranged in this order. (26) A water separation process by a compression and cooling separation method, a water separation process by an adsorption method, a hydrogen separation process by an adsorption method, and a carbon dioxide separation process by an absorption method are arranged in this order. (27) A water separation process by a compression and cooling separation method, a water separation process by an adsorption method, a hydrogen separation process by a membrane separation method, and a carbon dioxide separation process by a solid adsorption method are arranged in this order. (28) A water separation process by a compression and cooling separation method, a water separation process by an adsorption method, a hydrogen separation process by an adsorption method, and a carbon dioxide separation process by a solid adsorption method are arranged in this order.

[0051] (29) A hydrogen separation process by membrane separation, a water separation process by compression and cooling separation, a water separation process by adsorption, and a carbon dioxide separation process by absorption are arranged in this order. (30) A hydrogen separation process by adsorption, a water separation process by compression and cooling separation, a water separation process by adsorption, and a carbon dioxide separation process by absorption are arranged in this order. (31) A hydrogen separation process by membrane separation, a water separation process by compression and cooling separation, a water separation process by adsorption, and a carbon dioxide separation process by solid adsorption are arranged in this order. (32) A hydrogen separation process by adsorption, a water separation process by compression and cooling separation, a water separation process by adsorption, and a carbon dioxide separation process by solid adsorption are arranged in this order. (33) A hydrogen separation process by membrane separation, a water separation process by compression and cooling separation, a water separation process by adsorption, and a carbon dioxide separation process by membrane separation are arranged in this order. (34) A hydrogen separation process by adsorption, a water separation process by compression and cooling separation, a water separation process by adsorption, and a carbon dioxide separation process by membrane separation are arranged in this order.

[0052] The carbon dioxide (3a) and hydrogen (3c) obtained in the gas separation step (3) may be used as raw materials for synthesizing chemical products. Examples of the chemical products include formic acid, methane, ethanol, dimethyl ether, carbon monoxide, formaldehyde, and methanol. The chemical product is preferably methanol. The method for producing ethylene and propylene according to this embodiment may further include a step of synthesizing chemical products using the carbon dioxide (3a) and hydrogen (3c) as raw materials (chemical product synthesis step). The carbon dioxide and hydrogen may each be used for purposes other than the methanol synthesis step (5) and the methane synthesis step (5') described below. Examples of uses of hydrogen include fuel and raw materials for chemical reactions.

[0053] [Olefin Separation Step (4)] The method for producing ethylene and propylene according to this embodiment includes an olefin separation step (4) in which the gas component (3d) containing ethylene and propylene obtained in the gas separation step (3) is separated into a light boiling fraction (4a), ethylene (4b), propylene (4c), and a high boiling fraction (4d). Separation of the light boiling fraction, which is a component having a boiling point lower than that of ethylene, from ethylene, propylene, and the high boiling fraction, which is a component having a boiling point higher than that of propylene, is usually carried out by distillation. A known method can be used for the distillation, and it may be a single-stage distillation or a multi-stage distillation.

[0054] When the olefin separation step (4) is carried out by multi-stage distillation, the following distillation methods can be mentioned. (a) First distillation method (Fig. 11) First stage: The gas component (3d) is separated into a light-boiling point component (4a) and an ethylene- and propylene-containing component. Second stage: The ethylene- and propylene-containing component of the first stage is separated into a high-ethylene-containing component and a propylene-containing component. Third stage: The high-ethylene-containing component of the second stage is separated into ethylene (4b) and components other than ethylene (e.g., ethane). Fourth stage: The propylene-containing component of the second stage is separated into a high-propylene-containing component and a high-boiling point component (4d). Fifth stage: The high-propylene-containing component of the fourth stage is separated into propylene (4c) and components other than propylene (e.g., propane).

[0055] (b) Second distillation method (Figure 12) First stage: The gas component (3d) is separated into an ethylene-containing component and a propylene-containing component. Second stage: The ethylene-containing component of the first stage is separated into a light boiling point component (4a) and a high ethylene-containing component. Third stage: The high ethylene-containing component of the second stage is separated into ethylene (4b) and components other than ethylene (ethane, etc.). Fourth stage: The propylene-containing component of the first stage is separated into a high boiling point component (4d) and a high propylene-containing component. Fifth stage: The high propylene-containing component of the fourth stage is separated into propylene (4c) and components other than propylene (propane, etc.).

[0056] (c) Third Distillation Method (Figure 13) First stage: The gas component (3d) is separated into a high boiling point component (4d) and an ethylene and propylene-containing component. Second stage: The ethylene and propylene-containing component of the first stage is separated into a light boiling point component (4a) and an ethylene and propylene-containing component. Third stage: The ethylene and propylene-containing component of the second stage is separated into a high ethylene-containing component and a high propylene-containing component. Fourth stage: The high ethylene-containing component of the third stage is separated into ethylene (4b) and components other than ethylene (e.g., ethane). Fifth stage: The high propylene-containing component of the third stage is separated into propylene (4c) and components other than propylene (e.g., propane).

[0057] (d) Fourth Distillation Method (Figure 14) First stage: The gas component (3d) is separated into a light boiling point fraction (4a) and an ethylene and propylene-containing component. Second stage: The ethylene and propylene-containing component of the first stage is separated into a high boiling point fraction (4d) and an ethylene and propylene-containing component. Third stage: The ethylene and propylene-containing component of the second stage is separated into a high ethylene-containing component and a high propylene-containing component. Fourth stage: The high ethylene-containing component of the third stage is separated into ethylene (4b) and components other than ethylene (e.g., ethane). Fifth stage: The high propylene-containing component of the third stage is separated into propylene (4c) and components other than propylene (e.g., propane).

[0058] (e) Fifth Distillation Method (Figure 15) First stage: The gas component (3d) is separated into a high boiling point fraction (4d) and an ethylene- and propylene-containing component. Second stage: The ethylene- and propylene-containing component of the first stage is separated into an ethylene-containing component and a high propylene-containing component. Third stage: The ethylene-containing component of the second stage is separated into a light boiling point fraction (4a) and a high ethylene-containing component. Fourth stage: The high ethylene-containing component of the third stage is separated into ethylene (4b) and components other than ethylene (ethane, etc.). Fifth stage: The high propylene-containing component of the second stage is separated into propylene (4c) and components other than propylene (propane, etc.).

[0059] [Methanol Synthesis Step (5)] From the viewpoint of obtaining better productivity, as shown in FIG. 6 , the method for producing ethylene and propylene according to this embodiment may include a methanol synthesis step (5) in which methanol (5a) and water (5b) are obtained using carbon dioxide (3a) and hydrogen (3c) obtained in the gas separation step (3) as raw materials. Carbon monoxide may also be produced in the methanol synthesis step (5). The volume fraction of hydrogen and carbon dioxide (hydrogen / carbon dioxide) used in the synthesis reaction is preferably 1.0 or more and 5.0 or less, more preferably 2.0 or more and 4.0 or less, and even more preferably 2.5 or more and 3.5 or less. Carbon dioxide and hydrogen may be combined with other inert gas components and subjected to the synthesis reaction. Examples of inert gases include nitrogen, methane, and ethane.

[0060] The carbon dioxide (3a) and hydrogen (3c) obtained in the gas separation step (3) may be used in their entirety as raw materials in the methanol synthesis step (5), or a portion of each may be used as raw materials in the methanol synthesis step (5). Alternatively, a portion of the hydrogen may be used as raw material in the methanol synthesis step (5), and the remaining portion may be used as fuel.

[0061] In the methanol synthesis step (5), in order to increase the efficiency of the methanol synthesis reaction, in addition to the carbon dioxide (3a) and hydrogen (3c) obtained in the gas separation step (3), carbon dioxide and hydrogen obtained in a step other than the gas separation step (3) may be used. Examples of such carbon dioxide and hydrogen include those described in Unexamined Technical Publication No. 2024-500154.

[0062] The catalyst used in the methanol synthesis reaction is preferably a copper-based catalyst, more preferably a catalyst having copper and zinc as essential components and optionally containing aluminum, silicon, magnesium, a transition element (excluding scandium and yttrium), a rare earth element, and gallium, and even more preferably a catalyst having copper, zinc, and aluminum as essential components and optionally containing silicon, magnesium, a transition element (excluding scandium and yttrium), a rare earth element, and gallium. Examples of such catalysts include those described in JP-A-62-53740, JP-A-2010-194419, JP-A-2010-194420, JP-A-2010-194421, and WO 2013 / 183577.

[0063] From the viewpoint of increasing the yield of methanol, the methanol synthesis step (5) may include an extraction step in which at least a portion of the produced methanol (5a) and / or water (5b) is condensed or separated by membrane and discharged outside the methanol synthesis reaction system. By including an extraction step in the methanol synthesis step (5), the concentrations of methanol (5a) and water (5b) in the methanol synthesis reaction system can be kept low. Therefore, the equilibrium in the methanol synthesis reaction tends to favor the production of methanol (5a) and water (5b), thereby promoting the methanol synthesis reaction. As an apparatus for performing such a synthesis reaction, a reactor capable of condensing the produced methanol and water within the reactor is preferred. For example, the reactors described in JP 2005-298423 A, WO 2021 / 060145 A, and WO 2022 / 045326 A can be used.

[0064] The reaction temperature in the methanol synthesis step (5) is preferably 150°C or higher, more preferably 180°C or higher, and even more preferably 220°C or higher. The reaction temperature in the methanol synthesis step (5) is preferably 300°C or lower, more preferably 260°C or lower, and even more preferably 240°C or lower. When a reactor is used in the methanol synthesis step (5), the reaction temperature may be the temperature of the steam or catalyst inside the reactor. The reactor may be equipped with a thermometer inside the reactor for measuring the temperature of the steam or catalyst inside the reactor. The reaction pressure in the methanol synthesis step (5) is preferably 0.5 MPaA or higher, and more preferably 3 MPaA or higher. The reaction pressure in the methanol synthesis step (5) is preferably 10 MPaA or lower, and more preferably 8 MPaA or lower.

[0065] The methanol obtained in the methanol synthesis step (5) can be used in the methanol-to-olefin, methanol-to-ethylene, and methanol-to-propylene processes, and can be used as a raw material for synthesizing olefins such as ethylene, propylene, and butene. The methanol can also be used as a raw material for synthesizing other chemicals such as propane, butane, acetic acid, methyl acetate, methyl acrylate, and methyl methacrylate. The methanol can also be used as a raw material for synthesizing synthetic fuels using the methanol-to-gasoline, methanol-to-jet, and methanol-to-diesel processes.

[0066] The method for producing ethylene and propylene according to this embodiment may include an acetic acid synthesis step in which acetic acid is obtained from the methanol obtained in the methanol synthesis step (5) and carbon monoxide as raw materials. The carbon monoxide produced in the methanol synthesis step (5) can be used as a raw material for the acetic acid synthesis step. The method for producing ethylene and propylene according to this embodiment may also include an acetone synthesis step in which acetone is obtained from the acetic acid obtained in the acetic acid synthesis step as a raw material. The acetone can be used as a raw material for the reaction step (1).

[0067] [Methane Synthesis Step (5')] From the viewpoint of obtaining better productivity, the ethylene and propylene production method according to this embodiment may include a methane synthesis step (5') in which methane (5a') and water (5b') are obtained using carbon dioxide (3a) and hydrogen (3c) obtained in the gas separation step (3) as raw materials, as shown in FIG. 7 . The volume fraction of hydrogen and carbon dioxide (hydrogen / carbon dioxide) used in the synthesis reaction is preferably 1.5 or more and 5.5 or less, more preferably 2 or more and 5 or less, and even more preferably 2.5 or more and 4.5 or less. Carbon dioxide and hydrogen may be combined with other inert gas components and subjected to the synthesis reaction. Examples of inert gases include nitrogen.

[0068] The carbon dioxide (3a) and hydrogen (3c) obtained in the gas separation step (3) may be used in their entirety as raw materials in the methane synthesis step (5'), or a portion of each may be used as raw materials in the methane synthesis step (5'). Alternatively, a portion of the hydrogen may be used as raw material in the methane synthesis step (5'), and the remaining portion may be used as fuel.

[0069] In the methane synthesis step (5'), in order to increase the efficiency of the methane synthesis reaction, in addition to the carbon dioxide (3a) and hydrogen (3c) obtained in the gas separation step (3), carbon dioxide and hydrogen obtained in a step other than the gas separation step (3) may be used. Examples of such carbon dioxide and hydrogen include those described in Unexamined Technical Publication No. 2024-500154.

[0070] The catalyst used in the methane synthesis reaction is preferably at least one catalyst selected from the group consisting of nickel-based catalysts, ruthenium-based catalysts, cobalt-based catalysts, iron-based catalysts and palladium-platinum-based catalysts.

[0071] From the viewpoint of increasing the yield of methane, the methane synthesis step (5') may include an extraction step in which at least a portion of the produced methane (5a') and / or water (5b') is condensed or separated by membrane separation and discharged to the outside of the methane synthesis reaction system. By including the extraction step in the methane synthesis step (5'), the concentrations of methane (5a') and water (5b') in the methane synthesis reaction system can be kept low. Therefore, the equilibrium in the methane synthesis reaction is shifted toward the production of methane (5a') and water (5b'), thereby accelerating the methane synthesis reaction.

[0072] The reaction temperature in the methane synthesis step (5') is preferably 100°C or higher, more preferably 200°C or higher, and even more preferably 300°C or higher. Furthermore, the reaction temperature in the methane synthesis step (5') is preferably 700°C or lower, more preferably 600°C or lower, and even more preferably 500°C or lower. When a reactor is used in the methane synthesis step (5'), the reaction temperature may be the temperature of the steam or catalyst inside the reactor. The reactor may be equipped with a thermometer inside the reactor for measuring the temperature of the steam or catalyst inside the reactor. The reaction pressure in the methane synthesis step (5') is preferably 0 MPaA or higher, and more preferably 0.1 MPaA or higher. Furthermore, the reaction pressure in the methane synthesis step (5') is preferably 3 MPaA or lower, and more preferably 2 MPaA or lower.

[0073] The methane obtained in the methane synthesis step (5') can be used as fuel to supply the heat required in the reaction step (1).

[0074] [Acetone / Water Separation Step (6)] As shown in Fig. 8, the method for producing ethylene and propylene according to this embodiment may include an acetone / water separation step (6) in which the liquid component (2b) obtained in the gas-liquid separation step (2) is separated into a component (6a) mainly composed of acetone and a component (6b) mainly composed of water. The liquid component (2b) may contain components other than acetone. The liquid component (2b) may contain, for example, oxygenated hydrocarbons such as ethanol, acetaldehyde, and isopropanol.

[0075] An example of a method for separating component (6a) and component (6b) is distillation. The separation method may be carried out, for example, by supplying liquid component (2b) to a distillation column, recovering component (6a) mainly composed of acetone from the distillation column, and discharging component (6b) mainly composed of water. The distillation conditions for the distillation column are not particularly limited, and the distillation method may be carried out under any conditions. The separation method may also be carried out using a plurality of distillation columns, in which case the distillation pressures of the distillation columns may be different. For example, the first stage of the plurality of distillation columns may be a distillation column operating under positive pressure, and the second stage may be a distillation column operating under atmospheric pressure.

[0076] [Recycle Step (7)] As shown in Fig. 8 , the method for producing ethylene and propylene according to this embodiment may include a recycle step (7) in which the component (6a), mainly composed of acetone obtained in the acetone / water separation step (6), is supplied to the reaction step (1). The method for supplying the component (6a) to the reaction step (1) is not particularly limited. The component (6a) may be premixed with the raw material (1a) and supplied to the reactor, or the raw material (1a) and the component (6a) may be supplied separately to the reactor. Furthermore, a portion of the component (6a) may be added to the reaction step (1) and supplied to the gas-liquid separation step (2) and / or the acetone / water separation step (6).

[0077] When the raw material (1a) contains acetone, or when the component (6a) is supplied to the reaction step (1), the molar ratio of ethanol to acetone in the total raw materials supplied to the reaction step (1) (acetone (mol) / ethanol (mol)) is preferably 0.01 or more, from the viewpoint of further increasing the yield of ethylene and propylene. Furthermore, the molar ratio of ethanol to acetone in the total raw materials supplied to the reaction step (1) is preferably 1.7 or less, more preferably 1.6 or less, and even more preferably 1.5 or less.

[0078] From the viewpoint of reducing the proportion of unreacted substances, as shown in FIG. 8 , one aspect of the method for producing ethylene and propylene according to this embodiment includes an acetone / water separation step (6) for separating the liquid component (2b) obtained in the gas-liquid separation step (2) into a component (6a) mainly containing acetone and a component (6b) mainly containing water, and a recycle step (7) for supplying the component (6a) obtained in the acetone / water separation step (6) to the reaction step (1).

[0079] [Water Supply Step (8)] From the viewpoint of promoting the reaction in the reaction step (1), the method for producing ethylene and propylene according to this embodiment may include a water supply step (8) in which a component (6b) mainly composed of water obtained in the acetone / water separation step (6) is supplied to the reaction step (1), as shown in Fig. 9. The method for supplying the component (6b) to the reaction step (1) is not particularly limited, and the component (6b) may be premixed with the raw material (1a) and supplied to the reactor, or the component (6a) to be supplied to the reaction step (1) may be premixed with the raw material (1a) and supplied to the reactor, or the component (6a) to be supplied to the reaction step (1) and the raw material (1a) may be premixed and supplied to the reactor, or the component (6b) may be supplied to the reactor independently of the raw material (1a) and the component (6a) to be supplied to the reaction step (1).

[0080] When component (6b) is supplied to reaction step (1), or when water is supplied to reaction step (1) from a source other than raw material (1a), the molar ratio of water to ethanol in the total of all raw materials supplied to reaction step (1) (water (mol) / ethanol (mol)) is preferably 0.1 or more, more preferably 0.2 or more, and even more preferably 0.3 or more. In addition, the molar ratio of water to ethanol in the total of all raw materials supplied to reaction step (1) is preferably 10 or less, more preferably 8 or less, and even more preferably 5 or less.

[0081] From the viewpoint of obtaining better productivity, as shown in FIG. 10 , the method for producing ethylene and propylene according to this embodiment, as one aspect, includes a methanol synthesis step (5) for synthesizing methanol (5a) using carbon dioxide (3a) and hydrogen (3c) obtained in the gas separation step (3) as raw materials; an acetone / water separation step (6) for separating a liquid component (2b) obtained in the gas-liquid separation step (2) into a component (6a) mainly composed of acetone and a component (6b) mainly composed of water; a recycling step (7) for supplying the component (6a) obtained in the acetone / water separation step (6) to the reaction step (1); and a water supply step (8) for supplying the component (6b) obtained in the acetone / water separation step (6) to the reaction step (1).

[0082] From the viewpoint of improving the purity of the product, the ethylene and propylene production method according to this embodiment may include a desulfurization step for removing sulfur components at any stage after the gas-liquid separation step (2). In the desulfurization step, for example, sulfur components such as hydrogen sulfide and carbonyl sulfide are removed from the propylene-containing gas. Examples of stages in which the desulfurization step is performed include between the gas-liquid separation step (2) and the gas separation step (3), between the gas separation step (3) and the olefin separation step (4), within the gas separation step (3), and within the olefin separation step (4). Examples of the propylene-containing gas include gas component (2a), gas component (3d), gas component (3e), gas component (3f), gas component (3g), gas component (3h), gas component (3i), gas component (3j), and propylene (4c). The ethylene and propylene production method according to this embodiment preferably includes a desulfurization step for removing sulfur components from the gas component (3d) before it is supplied to the olefin separation step (4).

[0083] A method for removing sulfur components includes an adsorption method in which the sulfur components are adsorbed onto an adsorbent. Examples of adsorbents include physical adsorbents such as activated carbon, alumina, and zeolite, and chemical adsorbents such as iron oxide, zinc oxide, and potassium permanganate. Furthermore, these chemical adsorbents may be supported on a support such as alumina, silica, titania, silica-alumina, magnesia, or activated carbon.

[0084] The removal of sulfur components by the adsorption method is usually carried out by filling a packed tower with an adsorbent and passing a gas through the packed tower to adsorb the sulfur components in the gas onto the adsorbent. When using a packed tower to remove sulfur components by the adsorption method, preferably, two or more packed towers are filled with the adsorbent, and an adsorption step is carried out in at least one packed tower and a packing regeneration step is carried out in at least one packed tower. The removal of sulfur components by the adsorption method may be carried out multiple times using one or more adsorbents.

[0085] When heating is required in each step of the method for producing ethylene and propylene according to this embodiment, the heating method may be, for example, a heating method that uses hydrogen or ammonia as fuel and does not generate carbon dioxide, a heating method that uses electricity obtained by a method that does not emit carbon dioxide when generating electricity, etc. By using these heating methods, the method for producing ethylene and propylene according to this embodiment can reduce the amount of carbon dioxide emitted throughout the process.

[0086] According to the method for producing ethylene and propylene according to the present embodiment, it is possible to provide a method for producing ethylene and propylene using ethanol as a raw material with excellent productivity.

[0087] The present invention includes the following aspects.

[0088] <1> A method for producing ethylene and propylene, comprising: a reaction step (1) of contacting a raw material (1a) containing ethanol with a catalyst to obtain a product (1b) containing ethylene and propylene; a gas-liquid separation step (2) of separating the product (1b) obtained in the reaction step (1) into a gas component (2a) containing ethylene and propylene and a liquid component (2b) containing acetone; a gas separation step (3) of separating carbon dioxide (3a), water (3b), and hydrogen (3c) from the gas component (2a) obtained in the gas-liquid separation step (2) to obtain a gas component (3d) containing ethylene and propylene; and an olefin separation step (4) of separating the gas component (3d) containing ethylene and propylene obtained in the gas separation step (3) into a light boiling fraction (4a), ethylene (4b), propylene (4c), and a high boiling fraction (4d).

[0089] <2> The method for producing ethylene and propylene according to <1>, wherein the gas separation step (3) comprises: a carbon dioxide separation step (3-1) of separating carbon dioxide (3a) from the gas component (2a) obtained in the gas-liquid separation step (2) to obtain a gas component (3e); a water separation step (3-2) of separating water (3b) from the gas component (3e) obtained in the carbon dioxide separation step (3-1) to obtain a gas component (3f); and a hydrogen separation step (3-3) of separating hydrogen (3c) from the gas component (3f) obtained in the water separation step (3-2) to obtain a gas component (3d) containing ethylene and propylene.

[0090] <3> The method for producing ethylene and propylene according to <1>, wherein the gas separation step (3) comprises: a carbon dioxide / hydrogen separation step (3-4) of separating carbon dioxide (3a) and hydrogen (3c) from the gas component (2a) obtained in the gas-liquid separation step (2) to obtain a gas component (3g); and a water separation step (3-5) of separating water (3b) from the gas component (3g) obtained in the carbon dioxide / hydrogen separation step (3-4) to obtain a gas component (3d) containing ethylene and propylene.

[0091] <4> The method for producing ethylene and propylene according to <1>, wherein the gas separation step (3) comprises: a water separation step (3-6) of separating water (3b) from the gas component (2a) obtained in the gas-liquid separation step (2) to obtain a gas component (3h); and a carbon dioxide / hydrogen separation step (3-7) of separating carbon dioxide (3a) and hydrogen (3c) from the gas component (3h) obtained in the water separation step (3-6) to obtain a gas component (3d) containing ethylene and propylene.

[0092] <5> The method for producing ethylene and propylene according to <1>, wherein the gas separation step (3) comprises: a hydrogen separation step (3-8) of separating hydrogen (3c) from the gas component (2a) obtained in the gas-liquid separation step (2) to obtain a gas component (3i); a water separation step (3-9) of separating water (3b) from the gas component (3i) obtained in the hydrogen separation step (3-8) to obtain a gas component (3j); and a carbon dioxide separation step (3-10) of separating carbon dioxide (3a) from the gas component (3j) obtained in the water separation step (3-9) to obtain a gas component (3d) containing ethylene and propylene.

[0093] <6> The method for producing ethylene and propylene according to any one of <2> to <5>, wherein the water separation step (3-2), (3-5), (3-6) or (3-9) comprises: a condensation step of condensing water by compression and cooling; and an adsorption step of separating the water produced in the condensation step by an adsorption method.

[0094] <7> The method for producing ethylene and propylene according to any one of <1> to <6>, further comprising a methanol synthesis step (5) of obtaining methanol (5a) and water (5b) using carbon dioxide (3a) and hydrogen (3c) obtained in the gas separation step (3) as raw materials.

[0095] <8> The method for producing ethylene and propylene according to any one of <1> to <6>, further comprising a methane synthesis step (5′) of obtaining methane (5a′) and water (5b′) using the carbon dioxide (3a) and hydrogen (3c) obtained in the gas separation step (3) as raw materials.

[0096] <9> The method for producing ethylene and propylene according to <7>, wherein the methanol synthesis step (5) includes an extraction step of condensing or membrane-separating at least a portion of the produced methanol (5a) and / or water (5b) and discharging it from the methanol synthesis reaction system.

[0097] <10> The method for producing ethylene and propylene according to any one of <1> to <9>, comprising: an acetone / water separation step (6) of separating a liquid component (2b) obtained in the gas-liquid separation step (2) into a component (6a) mainly containing acetone and a component (6b) mainly containing water; and a recycling step (7) of supplying the component (6a) obtained in the acetone / water separation step (6) to the reaction step (1).

[0098] <11> The method for producing ethylene and propylene according to <10>, further comprising a water supply step (8) of supplying the component (6b) obtained in the acetone / water separation step (6) to the reaction step (1).

[0099] <12> The method for producing ethylene and propylene according to any one of <1> to <6>, comprising: a methanol synthesis step (5) of synthesizing methanol (5a) using carbon dioxide (3a) and hydrogen (3c) obtained in the gas separation step (3) as raw materials; an acetone / water separation step (6) of separating a liquid component (2b) obtained in the gas-liquid separation step (2) into a component (6a) mainly composed of acetone and a component (6b) mainly composed of water; a recycling step (7) of supplying the component (6a) obtained in the acetone / water separation step (6) to the reaction step (1); and a water supply step (8) of supplying the component (6b) obtained in the acetone / water separation step (6) to the reaction step (1).

[0100] <13> The method for producing ethylene and propylene according to any one of <1> to <12>, further comprising a raw material treatment step of contacting the raw material (1a) with an acid adsorbent before it is supplied to the reaction step (1).

[0101] <14> The method for producing ethylene and propylene according to any one of <1> to <13>, further comprising a desulfurization step of removing sulfur components from the gas component (3d) before it is supplied to the olefin separation step (4).

Claims

1. A method for producing ethylene and propylene, comprising: a reaction step (1) of contacting a raw material (1a) containing ethanol with a catalyst to obtain a product (1b) containing ethylene and propylene; a gas-liquid separation step (2) of separating the product (1b) obtained in the reaction step (1) into a gas component (2a) containing ethylene and propylene and a liquid component (2b) containing acetone; a gas separation step (3) of separating carbon dioxide (3a), water (3b), and hydrogen (3c) from the gas component (2a) obtained in the gas-liquid separation step (2) to obtain a gas component (3d) containing ethylene and propylene; and an olefin separation step (4) of separating the gas component (3d) containing ethylene and propylene obtained in the gas separation step (3) into a light boiling fraction (4a), ethylene (4b), propylene (4c), and a high boiling fraction (4d).

2. The method for producing ethylene and propylene according to claim 1, wherein the gas separation step (3) comprises: a carbon dioxide separation step (3-1) of separating carbon dioxide (3a) from the gas component (2a) obtained in the gas-liquid separation step (2) to obtain a gas component (3e); a water separation step (3-2) of separating water (3b) from the gas component (3e) obtained in the carbon dioxide separation step (3-1) to obtain a gas component (3f); and a hydrogen separation step (3-3) of separating hydrogen (3c) from the gas component (3f) obtained in the water separation step (3-2) to obtain a gas component (3d) containing ethylene and propylene.

3. The method for producing ethylene and propylene according to claim 1, wherein the gas separation step (3) comprises: a carbon dioxide / hydrogen separation step (3-4) of separating carbon dioxide (3a) and hydrogen (3c) from the gas component (2a) obtained in the gas-liquid separation step (2) to obtain a gas component (3g); and a water separation step (3-5) of separating water (3b) from the gas component (3g) obtained in the carbon dioxide / hydrogen separation step (3-4) to obtain a gas component (3d) containing ethylene and propylene.

4. The method for producing ethylene and propylene according to claim 1, wherein the gas separation step (3) comprises: a water separation step (3-6) of separating water (3b) from the gas component (2a) obtained in the gas-liquid separation step (2) to obtain a gas component (3h); and a carbon dioxide / hydrogen separation step (3-7) of separating carbon dioxide (3a) and hydrogen (3c) from the gas component (3h) obtained in the water separation step (3-6) to obtain a gas component (3d) containing ethylene and propylene.

5. The method for producing ethylene and propylene according to claim 1, wherein the gas separation step (3) comprises: a hydrogen separation step (3-8) of separating hydrogen (3c) from the gas component (2a) obtained in the gas-liquid separation step (2) to obtain a gas component (3i); a water separation step (3-9) of separating water (3b) from the gas component (3i) obtained in the hydrogen separation step (3-8) to obtain a gas component (3j); and a carbon dioxide separation step (3-10) of separating carbon dioxide (3a) from the gas component (3j) obtained in the water separation step (3-9) to obtain a gas component (3d) containing ethylene and propylene.

6. The method for producing ethylene and propylene according to any one of claims 2 to 5, wherein the water separation step (3-2), (3-5), (3-6) or (3-9) comprises a condensation step of condensing water by compression and cooling, and an adsorption step of separating the water produced in the condensation step by an adsorption method.

7. The method for producing ethylene and propylene according to claim 6, further comprising a methanol synthesis step (5) for obtaining methanol (5a) and water (5b) using carbon dioxide (3a) and hydrogen (3c) obtained in the gas separation step (3) as raw materials.

8. The method for producing ethylene and propylene according to claim 6, further comprising a methane synthesis step (5') for obtaining methane (5a') and water (5b') using carbon dioxide (3a) and hydrogen (3c) obtained in the gas separation step (3) as raw materials.

9. The method for producing ethylene and propylene according to claim 7, wherein the methanol synthesis step (5) comprises an extraction step of condensing or membrane separating at least a portion of the produced methanol (5a) and / or water (5b) and removing it from the methanol synthesis reaction system.

10. A method for producing ethylene and propylene according to any one of claims 1 to 5, comprising: an acetone / water separation step (6) for separating a liquid component (2b) obtained in the gas-liquid separation step (2) into a component (6a) mainly composed of acetone and a component (6b) mainly composed of water; and a recycling step (7) for supplying the component (6a) obtained in the acetone / water separation step (6) to the reaction step (1).

11. The method for producing ethylene and propylene according to claim 10, further comprising a water supply step (8) for supplying the component (6b) obtained in the acetone / water separation step (6) to the reaction step (1).

12. A method for producing ethylene and propylene according to any one of claims 1 to 5, comprising: a methanol synthesis step (5) for synthesizing methanol (5a) using carbon dioxide (3a) and hydrogen (3c) obtained in the gas separation step (3) as raw materials; an acetone / water separation step (6) for separating a liquid component (2b) obtained in the gas-liquid separation step (2) into a component (6a) mainly composed of acetone and a component (6b) mainly composed of water; a recycling step (7) for supplying the component (6a) obtained in the acetone / water separation step (6) to the reaction step (1); and a water supply step (8) for supplying the component (6b) obtained in the acetone / water separation step (6) to the reaction step (1).

13. The method for producing ethylene and propylene according to any one of claims 1 to 5, further comprising a raw material treatment step of contacting the raw material (1a) with an acid adsorbent before it is supplied to the reaction step (1).

14. The method for producing ethylene and propylene according to any one of claims 1 to 5, further comprising a desulfurization step for removing sulfur components from the gas component (3d) before it is supplied to the olefin separation step (4).

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