Ethylene production apparatus and ethylene production method

Abstract

This ethylene production apparatus for producing ethylene from a methane-containing gas is provided with a ceramic film having oxide ion conductivity and / or proton conductivity, a first catalyst layer that is provided on one surface of the ceramic film and that is provided with a catalyst for accelerating a methane oxidization coupling reaction, a methane supply unit for supplying the methane-containing gas to a space on the one surface side of the ceramic film, and an electric charge transfer unit that transfers electrons from one surface to the other surface of the ceramic film, or transfers holes from the other surface to the one surface of the ceramic film. When the methane-containing gas is supplied by the methane supply unit, ethylene is generated at the first catalyst layer.

Description

Technical Field

[0001] The present disclosure relates to an ethylene production apparatus and an ethylene production method.

Background Art

[0002] Conventionally, as methods for producing ethylene, methods such as pyrolyzing and fractionating higher hydrocarbons such as naphtha, and methods for pyrolyzing ethane derived from natural gas are known. Further, as another method, a method for producing ethylene by converting methane to ethylene by a methane oxidative coupling reaction using a catalyst has been proposed (see, for example, Patent Document 1 and Non-Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Non-Patent Documents

[0004]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The method using a methane oxidative coupling catalyst is advantageous in that it can reduce the amount of energy to be input during the production of ethylene as compared with the method of producing ethylene by pyrolyzing hydrocarbons. In the production of ethylene using such a methane oxidative coupling catalyst, from the viewpoint of industrialization, further improvement in the efficiency of ethylene production has been desired.

Means for Solving the Problems

[0006] The present disclosure can be realized in the following forms. (1) According to one aspect of the present disclosure, an ethylene production apparatus for producing ethylene from a methane-containing gas is provided. This ethylene production apparatus includes a ceramic membrane having at least one of oxide ion conductivity and proton conductivity, a first catalyst layer provided on one surface of the ceramic membrane and including a catalyst that promotes a methane oxidative coupling reaction that produces ethylene from methane, a methane supply unit that supplies the methane-containing gas to a space on the one surface side of the two spaces separated by the ceramic membrane, and a charge transfer unit that moves electrons from one surface of the ceramic membrane to the other surface or moves holes from the other surface of the ceramic membrane to the one surface. When the methane-containing gas is supplied to the space on the one surface side by the methane supply unit, ethylene is generated in the first catalyst layer. According to the ethylene production apparatus of this aspect, when the methane oxidative coupling reaction proceeds in the first catalyst layer, the operation of moving oxide ions or protons in the ceramic membrane and the operation of moving electrons or holes between one surface and the other surface of the ceramic membrane by the charge transfer unit can be continuously performed. Therefore, the progress of the methane oxidative coupling reaction can be promoted, and the efficiency of the entire reaction for producing ethylene from methane can be increased. (2) The ethylene production apparatus of the above aspect further includes an oxygen supply unit that supplies an oxygen-containing gas containing oxygen to a space on the other surface side of the ceramic membrane. The charge transfer unit includes an external circuit that connects one surface and the other surface of the ceramic membrane, and electrons may be moved from one surface of the ceramic membrane to the other surface via the external circuit by an electromotive force generated due to a potential difference between one surface of the ceramic membrane and the other surface of the ceramic membrane. With such a configuration, the production efficiency of ethylene can be increased, and power can be extracted from the ethylene production apparatus along with the production of ethylene. (3) In the ethylene production apparatus of the above-described embodiment, the ceramic membrane has oxide ion conductivity, and the ethylene production apparatus may further include a second catalyst layer provided on the other surface of the ceramic membrane and including a catalyst that promotes a reaction of generating oxide ions from oxygen. With such a configuration, by providing the second catalyst layer, the production efficiency of ethylene can be further increased. (4) In the ethylene production apparatus of the above-described embodiment, the ceramic membrane has proton conductivity, and the ethylene production apparatus may further include a second catalyst layer provided on the other surface of the ceramic membrane and including a catalyst that promotes a reaction of generating water using oxygen and protons. With such a configuration, by providing the second catalyst layer, the production efficiency of ethylene can be further increased. (5) In the ethylene production apparatus of the above-described embodiment, the ceramic membrane has proton conductivity, and the ethylene production apparatus further includes an inert gas supply unit that supplies an inert gas to the space on the other surface side of the ceramic membrane, or a pressure reducing unit that reduces the pressure of the space on the other surface side of the ceramic membrane, and a second catalyst layer provided on the other surface of the ceramic membrane and including a catalyst that promotes a reaction of generating hydrogen from protons. The charge transfer unit includes an external circuit that connects the one surface and the other surface of the ceramic membrane, and electrons may be moved from the one surface to the other surface of the ceramic membrane through the external circuit by an electromotive force generated due to a potential difference between the one surface and the other surface of the ceramic membrane. With such a configuration, by providing the second catalyst layer, the production efficiency of ethylene can be further increased, and power can be extracted from the ethylene production apparatus along with the production of ethylene. Also, hydrogen can be produced in the ethylene production apparatus along with the production of ethylene. (6) In the ethylene production apparatus of the above-described embodiment, the ceramic film has proton conductivity, and the ethylene production apparatus further includes a carbon dioxide supply unit that supplies a carbon dioxide-containing gas containing carbon dioxide to the space on the other surface side of the ceramic film, and a second catalyst layer provided on the other surface of the ceramic film and including a catalyst that promotes a reaction of generating methane using carbon dioxide and protons. The charge transfer unit includes an external circuit that connects the one surface and the other surface of the ceramic film, and electrons may be moved from the one surface to the other surface of the ceramic film through the external circuit by an electromotive force generated due to a potential difference between the one surface and the other surface of the ceramic film. With such a configuration, by providing the second catalyst layer, the production efficiency of ethylene can be further increased, and it becomes possible to extract electric power from the ethylene production apparatus along with the production of ethylene. Also, it becomes possible to produce methane in the ethylene production apparatus along with the production of ethylene. (7) In the ethylene production apparatus of the above-described embodiment, the ceramic film has at least one of electron conductivity and hole conductivity in addition to at least one of oxide ion conductivity and proton conductivity, the charge transfer unit is the ceramic film, and with the generation of ethylene on the one surface of the ceramic film, electrons may be moved from the one surface to the other surface within its own interior, or holes may be moved from the other surface to the one surface. With such a configuration, since an external circuit is not required for the movement of charges, the apparatus configuration can be simplified. (8) In the ethylene production apparatus of the above-described embodiment, the ceramic membrane has oxide ion conductivity and at least one of electron conductivity and hole conductivity, and the ethylene production apparatus further includes an oxygen supply unit that supplies an oxygen-containing gas containing oxygen to the space on the other surface side of the ceramic membrane, and a second catalyst layer provided on the other surface of the ceramic membrane and including a catalyst that promotes a reaction for generating oxide ions from oxygen. With such a configuration, by providing the second catalyst layer, the production efficiency of ethylene can be further increased. (9) In the ethylene production apparatus of the above-described embodiment, the ceramic membrane has proton conductivity and at least one of electron conductivity and hole conductivity, and the ethylene production apparatus further includes an oxygen supply unit that supplies an oxygen-containing gas containing oxygen to the space on the other surface side of the ceramic membrane, and a second catalyst layer provided on the other surface of the ceramic membrane and including a catalyst that promotes a reaction using oxygen and protons. With such a configuration, by providing the second catalyst layer, the production efficiency of ethylene can be further increased. (10) In the ethylene production apparatus of the above-described embodiment, the ceramic membrane has proton conductivity, and the ethylene production apparatus further includes an inert gas supply unit that supplies an inert gas to the space on the other surface side of the ceramic membrane, or a pressure reducing unit that reduces the pressure of the space on the other surface side of the ceramic membrane, and a second catalyst layer provided on the other surface of the ceramic membrane and including a catalyst that promotes a reaction for generating hydrogen from protons. With such a configuration, by providing the second catalyst layer, the production efficiency of ethylene can be further increased, and it becomes possible to produce hydrogen in the ethylene production apparatus along with the production of ethylene. (11) In the ethylene production apparatus of the above-described embodiment, the ceramic membrane has proton conductivity, and the ethylene production apparatus further includes a carbon dioxide supply unit that supplies a carbon dioxide-containing gas containing carbon dioxide to the space on the other surface side of the ceramic membrane, and a second catalyst layer provided on the other surface of the ceramic membrane and including a catalyst that promotes a reaction for generating methane using carbon dioxide and protons. With such a configuration, by providing the second catalyst layer, the production efficiency of ethylene can be further increased, and it becomes possible to produce methane in the ethylene production apparatus along with the production of ethylene. (12) The ethylene production apparatus of the above-described embodiment may further include a methane recovery unit that mixes the methane generated on the other surface of the ceramic membrane with the methane-containing gas supplied by the methane supply unit to the space on the one surface side of the ceramic membrane. With such a configuration, since the methane generated in the second catalyst layer along with the generation of ethylene is mixed by the methane recovery unit with the methane-containing gas supplied to the space on the one surface side of the ceramic membrane, the amount of methane to be supplied from the methane supply unit to the ethylene production apparatus for the production of ethylene can be reduced, and the utilization efficiency of methane can be improved. (13) In the ethylene production apparatus of the above-described embodiment, the catalyst included in the first catalyst layer has the general formula (A 1-x A' x )(Zr 1-y-z B y B' z )O 3(However, A is at least one element selected from alkaline earth metals, A' is at least one element selected from lanthanum (La) and yttrium (Y), B is at least one element selected from titanium (Ti) and cerium (Ce), and B' is at least one element selected from yttrium (Y), scandium (Sc), ytterbium (Yb), aluminum (Al), indium (In), and neodymium (Nd)). It may have a perovskite structure represented by the formula, and x, y, and z may satisfy 0 ≦ x ≦ 0.4, 0.3 ≦ (1 - z) ≦ 1, 0 ≦ y, and 0 < (1 - y - z). With such a configuration, the efficiency of ethylene production in the ethylene production apparatus can be further increased.) (14) In the ethylene production apparatus of the above aspect, the charge transfer unit may include an external circuit connecting the one surface and the other surface of the ceramic film, and an external power source connected to the external circuit. By the electromotive force of the external power source, electrons may be moved from the one surface of the ceramic film to the other surface through the external circuit. With such a configuration, the production efficiency of ethylene can be increased.) (15) According to another aspect of the present disclosure, an ethylene production method for producing ethylene from a methane-containing gas is provided. In this ethylene production method, in one of two spaces separated by a ceramic film having at least one of oxide ion conductivity and proton conductivity, a first catalyst layer including a catalyst that promotes a methane oxidative coupling reaction for generating ethylene from methane is provided on one surface side of the space of the ceramic film. The methane-containing gas is supplied to the space, and charge transfer is performed between the one surface and the other surface by moving electrons from the one surface of the ceramic film to the other surface or moving holes from the other surface of the ceramic film to the one surface, so that ethylene is generated from methane in the methane-containing gas in the first catalyst layer.) According to the ethylene production method of this embodiment, when the methane oxidative coupling reaction proceeds in the first catalyst layer, the operations of the movement of oxide ions and protons in the ceramic membrane and the movement of electrons and holes between one surface and the other surface of the ceramic membrane can be continuously performed. Therefore, the progress of the methane oxidative coupling reaction can be promoted, and the efficiency of the entire reaction of generating ethylene from methane can be increased. The present disclosure can be realized in various forms other than the above, for example, it can be realized in the form of a method for producing ethylene.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Embodiments for Carrying Out the Invention

[0008] A. First Embodiment: FIG. 1 is an explanatory diagram showing a schematic configuration of an ethylene production apparatus 101 as a first embodiment of the present disclosure. The ethylene production apparatus 101 is an apparatus for producing ethylene from a methane-containing gas. The ethylene production apparatus 101 includes a ceramic membrane 20, a first catalyst layer 22 formed on one surface of the ceramic membrane 20, a methane supply unit 30, an oxygen supply unit 32, and a charge transfer unit 40. In the following description, the surface of the ceramic membrane 20 on which the first catalyst layer 22 is formed is referred to as the "one surface", and the surface on the side different from the surface on which the first catalyst layer 22 is formed is referred to as the "other surface". Also, the ceramic membrane 20 and the first catalyst layer 22 together are also referred to as the "membrane structure 21". The ethylene production apparatus 101 further includes a housing (not shown) in which two spaces partitioned by a partition are formed. The membrane structure 21 including the ceramic membrane 20 is assembled to the above-described housing and constitutes at least a part of the above-described partition. In the ethylene production apparatus 101, of the two spaces separated by the membrane structure 21, the space on the one surface side where the first catalyst layer 22 is formed is referred to as the first space 24, and the space on the other surface side of the ceramic membrane 20 is referred to as the second space 26.

[0009] The ceramic membrane 20 is a gas-impermeable dense membrane made of ceramics. The ceramic membrane 20 of the present embodiment is configured as a self-supporting membrane without a carrier (substrate or support), unlike a membrane formed on the surface of a carrier. Further, the ceramic membrane 20 contains an oxide ion conductor and exhibits oxide ion conductivity under the use temperature and use atmosphere of the ethylene production apparatus 101.

[0010] As the oxide ion conductor contained in the ceramic film 20, for example, at least one oxide ion conductor selected from stabilized zirconia, partially stabilized zirconia, and ceria-based solid solutions can be used. Stabilized zirconia is zirconia stabilized by solid-solubilizing one or more dopants that are oxides in zirconium oxide (ZrO 2 ). Examples of the oxides that can be used as dopants include, for example, yttrium oxide (Y 2 O 3 ), scandium oxide (Sc 2 O 3 ), ytterbium oxide (Yb 2 O 3 ), calcium oxide (CaO), and magnesium oxide (MgO). From the viewpoint of improving oxide ion conductivity and stability, stabilized zirconia is preferably selected from yttria-stabilized zirconia (hereinafter also referred to as YSZ) and scandia-stabilized zirconia (hereinafter also referred to as ScSZ). Examples of the ceria-based solid solutions include cerium-based composite oxides such as gadolinium-doped ceria (GDC) and samarium-doped ceria (SDC).

[0011] To fabricate the ceramic film 20, for example, powders of raw materials such as the oxides described above may be prepared, formed by press molding or the like, and then fired. The film thickness of the ceramic film 20 can be, for example, 1 to 1000 μm, but may be less than 1 μm if the strength and denseness of the ceramic film 20 are within an acceptable range, and may exceed 1000 μm if the decrease in oxide ion conduction efficiency due to the thickening of the ceramic film 20 is within an acceptable range.

[0012] The first catalyst layer 22 includes a methane oxidative coupling catalyst that promotes a methane oxidative coupling reaction for producing ethylene from methane. The catalyst included in the first catalyst layer 22 may be any catalyst that promotes the methane oxidative coupling reaction, and various mixtures of conventionally known oxides or composite oxides can be used. The first catalyst layer 22 may further have at least one of proton conductivity, electron conductivity, hole conductivity, and oxide ion conductivity. Even when the first catalyst layer 22 has oxide ion conductivity, the ceramic film 20 of the present embodiment has higher oxide ion conductivity than the first catalyst layer 22.

[0013] The methane oxidative coupling catalyst included in the first catalyst layer 22 is, for example, a compound represented by the general formula (A 1-x A' x )(Zr 1-y-z B y B' z )O 3 (where A is at least one element selected from alkaline earth metals, A' is at least one element selected from lanthanum (La) and yttrium (Y), B is at least one element selected from titanium (Ti) and cerium (Ce), and B' is at least one element selected from yttrium (Y), scandium (Sc), ytterbium (Yb), aluminum (Al), indium (In), and neodymium (Nd)), having a perovskite structure, and the x, the y, and the z satisfy 0 ≦ x ≦ 0.4, 0.3 ≦ (1 - z) ≦ 1, 0 ≦ y, 0 < (1 - y - z), and can be a composite oxide.

[0014] The above-mentioned methane oxidative coupling catalyst can be prepared, for example, by the complex polymerization method. The complex polymerization method is a well-known method capable of preparing a composite oxide with a good mixing state of component elements. Specifically, using a powder raw material such as metal nitrate, the powder raw material is weighed and dissolved in water so that the mixing ratio of the metal elements in the powder raw material is a ratio corresponding to the composition of the composite oxide to be prepared, and an oxycarboxylic acid such as citric acid is added to form a metal oxycarboxylic acid complex. Then, glycol or the like is added thereto and heated to advance the polymerization reaction to obtain a polyester polymer gel. And by heat-treating (firing) this polyester polymer gel, a composite oxide powder can be obtained.

[0015] The method for manufacturing an oxide ion conductor or a methane oxidative coupling catalyst may be a method other than the above-mentioned complex polymerization method. For example, various methods capable of manufacturing a composite oxide such as a solid phase reaction method, a coprecipitation method, or a sol-gel method can be adopted.

[0016] The first catalyst layer 22 can be formed, for example, by pasting the powder of the above-mentioned methane oxidative coupling catalyst using a solvent, applying this paste onto the ceramic film 20, and firing it. Alternatively, the first catalyst layer 22 may be formed on the ceramic film 20 by various film-forming methods such as a PVD method (physical vapor deposition method), specifically, for example, a PLD method (pulsed laser deposition method), a dip method, a thermal spraying method, or a sputtering method.

[0017] Further, the first catalyst layer 22 may be configured using a supported catalyst in which a methane oxidative coupling catalyst is supported on a porous body powder used as a carrier. The porous body powder used as a carrier is, for example, CeO 2 , γ-Al 2 O 3 , zeolite, SiO 2 , ZrO 2 , Na 2 WO 4 , La 2 O 3 , Cs 2 SO 4 , Sm 2 O 3, MgO, SrO, Y 2 O 3 , (La,Sr)AlO 3 , LaAlO 3 It can be composed of a material selected from. At this time, the particle size of the porous body powder is larger than the particle size of the catalyst supported on the porous body powder. For example, it may be 10 nm to 10 μm. As a method for supporting the methane oxidative coupling catalyst on the carrier, various known methods such as an impregnation method can be used.

[0018] By producing the first catalyst layer 22 which is porous by the method as described above, while widely securing the surface area of the catalyst for the methane oxidative coupling reaction to proceed, the gas can be made to flow well on the catalyst surface.

[0019] The thickness of the first catalyst layer 22 may be appropriately set according to the degree of catalytic activity of the catalyst included in the first catalyst layer 22, the degree of oxide ion conductivity or electron conductivity of the first catalyst layer 22, the porosity in the first catalyst layer 22, etc., so as to obtain the desired performance for producing ethylene. The thickness of the first catalyst layer 22 may be thinner or thicker than the thickness of the ceramic film 20.

[0020] The first catalyst layer 22 may be configured using a composite catalyst containing at least one of a metal catalyst and an oxide catalyst in addition to the methane oxidative coupling catalyst. That is, the above-described methane oxidative coupling catalyst and a metal catalyst or an oxide catalyst may be combined, for example, by mixing both to form a composite catalyst, and the first catalyst layer 22 may be configured using the composite catalyst. Thereby, the effect of promoting the methane oxidative coupling reaction proceeding in the first catalyst layer 22 can be enhanced. It is known that the metal catalyst and the oxide catalyst promote the dehydrogenation reaction included in the methane oxidative coupling reaction and also promote the oxidation reaction. Therefore, when the oxidation reaction proceeds by using the metal catalyst and the oxide catalyst, carbon dioxide may also be generated as a product instead of the target ethylene. However, when the metal catalyst or the oxide catalyst is combined with the methane oxidative coupling catalyst as in the present embodiment, the coupling reaction proceeds preferentially over the oxidation reaction, and as a result, the production of ethylene can be further promoted. As the metal catalyst, for example, a metal selected from palladium (Pd), copper (Cu), iron (Fe), nickel (Ni), platinum (Pt), indium (In), manganese (Mn), ruthenium (Ru), strontium (Sr), zinc (Zn), and lithium (Li) can be used. As the oxide catalyst, for example, Li 2 ASiO 4 (A is Ca or Sr), Ce 2 (WO 4 ) 3 , CeO 2 oxides selected from can be used. When producing the composite catalyst, the above-described catalysts can be combined using various known methods such as an impregnation method, whether or not the carrier described above is used.

[0021] The methane supply unit 30 is a device that supplies a methane-containing gas to the first space 24, which is one of the two spaces separated by the ceramic membrane 20 in the ethylene production apparatus 101 and is the space on the side where the first catalyst layer 22 is formed. As the methane-containing gas, for example, natural gas mainly composed of methane may be used, or methane gas substantially containing no other components may also be used.

[0022] The oxygen supply unit 32 is a device that supplies an oxygen-containing gas to the second space 26, which is the other space on the side different from the side where the first catalyst layer 22 is formed among the two spaces separated by the ceramic membrane 20 in the ethylene production apparatus 101. As the oxygen-containing gas, for example, air may be used, or oxygen gas substantially containing no other components may also be used.

[0023] The charge transfer unit 40 moves electrons from one surface of the ceramic membrane 20 where the first catalyst layer 22 is formed to the other surface. Specifically, the charge transfer unit 40 of the present embodiment includes an external circuit 42 that connects one surface and the other surface of the ceramic membrane 20, and a load unit 43 connected to the external circuit 42. Then, due to the electromotive force generated by the potential difference between one surface and the other surface of the ceramic membrane 20, electrons are moved from one surface of the ceramic membrane 20 to the other surface via the external circuit 42. That is, in the present embodiment, when the ethylene production apparatus 101 produces ethylene from methane, power generation is performed in the ethylene production apparatus 101, and power can be extracted via the external circuit 42. The load unit 43 may be any device that extracts the power generated by the ethylene production apparatus 101 during ethylene production. The load unit 43 can be various power-consuming devices, and may also include a power storage device such as a battery or a capacitor that stores the generated power.

[0024] The following describes the Oxidative Coupling of Methane (OCM) reaction, which is a reaction related to ethylene production and proceeds in the ethylene production apparatus 101. In the ethylene production apparatus 101, in the first catalyst layer 22 formed on one surface of the ceramic membrane 20, the reaction of the following formula (1) proceeds, and on the other surface of the ceramic membrane 20, the reaction of the following formula (2) proceeds. In the entire ethylene production apparatus 101, the reaction of the following formula (3) proceeds.

[0025] 2CH 4 +2O 2- → C 2 H 4 +2H 2 O+4e - … (1) O 2 +4e - → 2O 2- … (2) 2CH 4 +2O 2 → C 2 H 4 +2H 2 O … (3)

[0026] That is, in the first catalyst layer 22, a reaction that produces ethylene, water, and electrons proceeds using methane supplied to the first space 24 and oxide ions supplied from the other surface of the ceramic membrane 20 through the inside of the ceramic membrane 20 ((Equation (1))). By continuously supplying the methane-containing gas to the first space 24, the gas containing ethylene and water generated in the first catalyst layer 22 is discharged from the first space 24 through a discharge channel (not shown). Further, on the other surface of the ceramic membrane 20, a reaction that produces oxide ions from oxygen and electrons supplied to the second space 26 proceeds ((Equation (2))). At this time, electrons move from one surface of the ceramic membrane 20 to the other surface via the external circuit 42. By these reactions, in the ethylene production apparatus 101, when the methane-containing gas is supplied to the first space 24 by the methane supply unit 30 and the oxygen-containing gas is supplied to the second space 26 by the oxygen supply unit 32, ethylene is generated in the first catalyst layer 22, and power is taken out from the ethylene production apparatus 101 together with ethylene.

[0027] In FIG. 1, the ethylene production apparatus 101 is described as having a configuration including a single flat ceramic membrane 20, but the ethylene production apparatus 101 can be in various forms. For example, the ceramic membrane 20 may be formed in a cylindrical shape. In this case, for example, the first catalyst layer 22 may be formed on the inner peripheral surface of the cylindrical ceramic membrane 20, the inside of the cylinder may be the first space 24, the outside of the cylindrical ceramic membrane 20 may be exposed to the outside air, and the outside of the cylinder may be the second space 26 through which air, which is an oxygen-containing gas, flows. Then, a channel for supplying the methane-containing gas from the methane supply unit 30 to the first space 24 may be connected to one end of the cylindrical ceramic membrane 20, and a channel for taking out the generated ethylene from the first space 24 may be connected to the other end of the cylindrical ceramic membrane 20. Alternatively, a plurality of flat ceramic membranes 20 may be stacked, the first space 24 and the second space 26 may be alternately provided between the stacked plurality of ceramic membranes 20, and the first catalyst layer 22 may be formed on the surface of the ceramic membrane 20 that is exposed to the first space 24.

[0028] According to the ethylene production apparatus 101 of the present embodiment configured as described above, the operation of supplying oxide ions to the first catalyst layer 22 where the methane oxidative coupling reaction proceeds and the operation of moving electrons from the first catalyst layer 22 using the charge transfer unit 40 having the external circuit 42 can be continuously performed. Therefore, among the reactions included in the methane oxidative coupling reaction, the reaction of generating methyl radicals from methane can be promoted, and the efficiency of the entire reaction of generating ethylene from methane can be increased. Hereinafter, the reaction of generating methyl radicals from methane will be further described.

[0029] When the above-described methane oxidative coupling reaction proceeds, the reaction that proceeds in the first catalyst layer 22 represented by the formula (1) is considered to proceed via a plurality of reactions as shown by the following formulas (4) to (6), for example. Formula (4) represents the reaction of generating methyl radicals from methane, formula (5) represents the reaction of methyl radicals coupling to generate ethane, and formula (6) represents the reaction of generating ethylene from ethane.

[0030] 2CH 4 +O 2- → 2·CH 3 +H 2 O+2e - … (4) 2·CH 3 → C 2 H 6 … (5) C 2 H 6 +O 2- → C 2 H 4 +H 2 O+2e - … (6)

[0031] The covalent bond between the carbon atom and the hydrogen atom in methane has a bond energy of 104 kcal / mol and is an extremely stable bond. Therefore, in the methane oxidative coupling reaction, generally, the reaction shown by formula (4) that generates methyl radicals from methane having the above-stable covalent bond is considered to be the rate-determining step. Thus, for promoting the methane oxidative coupling reaction, promoting the reaction that generates the above-mentioned methyl radicals is important. The ethylene production apparatus 101 of the present embodiment uses a ceramic membrane 20 having oxide ion conductivity, supplies methane to a first catalyst layer 22 provided on one surface of the ceramic membrane 20, supplies oxygen to the other surface of the ceramic membrane 20, and moves electrons from one surface of the ceramic membrane 20 to the other surface. Therefore, when the methane oxidative coupling reaction proceeds, oxide ions are supplied to the first catalyst layer 22 through the ceramic membrane 20, and electrons are extracted from the first catalyst layer 22 by the charge transfer section 40, whereby the reaction shown by formula (4) is promoted. In this way, as a result of promoting the reaction for generating methyl radicals, which is the rate-determining step, the entire reaction for generating ethylene from methane is promoted, and the production efficiency of ethylene can be increased.

[0032] Further, in the ethylene production apparatus 101 of the present embodiment, by providing a first catalyst layer 22 including a methane oxidative coupling catalyst on a ceramic membrane 20 having relatively high oxide ion conductivity, the production efficiency of ethylene is increased. As the methane oxidative coupling catalyst, for example, as described above, the general formula (A 1-x A' x )(Zr 1-y-z B y B' z )O 3(However, A is at least one element selected from alkaline earth metals, A' is at least one element selected from lanthanum (La) and yttrium (Y), B is at least one element selected from titanium (Ti) and cerium (Ce), and B' is at least one element selected from yttrium (Y), scandium (Sc), ytterbium (Yb), aluminum (Al), indium (In), and neodymium (Nd)). A composite oxide having a perovskite structure represented by the formula, wherein x, y, and z satisfy 0 ≦ x ≦ 0.4, 0.3 ≦ (1 - z) ≦ 1, 0 ≦ y, and 0 < (1 - y - z), can be used. Such a methane oxidative coupling catalyst has a relatively high activity for promoting the reaction of generating methyl radicals from methane. As a result, it has a relatively high activity for generating C 2 hydrocarbons such as ethylene from methane, and thus the production efficiency of ethylene can be further increased.

[0033] Furthermore, according to the ethylene production apparatus 101 of the present embodiment, power generation is performed in association with the reaction for producing ethylene. If the generated electric power is used, for example, in the methane supply section 30 or the oxygen supply section 32 of the ethylene production apparatus 101, the energy efficiency of the entire ethylene production apparatus 101 can be increased. Also, the generated electric power may be used in an apparatus other than the ethylene production apparatus 101.

[0034] B. Second Embodiment: FIG. 2 is an explanatory diagram showing a schematic configuration of an ethylene production apparatus 102 according to the second embodiment. The ethylene production apparatus 102 has the same structure as the ethylene production apparatus 101 of the first embodiment, except that it includes a ceramic membrane 120 instead of the ceramic membrane 20. Hereinafter, the ceramic membrane 120 and the first catalyst layer 22 are collectively referred to as a "membrane structure 121".

[0035] The ceramic membrane 120 included in the ethylene production apparatus 102 is a gas-impermeable dense membrane composed of ceramics and is configured as a self-supporting membrane. Further, the ceramic membrane 120 contains a proton conductor and exhibits proton conductivity under the operating temperature and atmosphere of the ethylene production apparatus 102.

[0036] As the proton conductor contained in the ceramic membrane 120, various conventionally known proton conductors can be used. Specifically, for example, perovskite-type complex oxides such as BaZrO 3 -based, BaCeO 3 , SrZrO 3 -based, or SrCeO 3 -based can be used. Such complex oxides can be produced, for example, by the above-described complex polymerization method, solid-phase reaction method, coprecipitation method, or sol-gel method.

[0037] Hereinafter, the methane oxidative coupling reaction, which is a reaction related to ethylene production and proceeds in the ethylene production apparatus 102, will be described. In the ethylene production apparatus 102, in the first catalyst layer 22 formed on one surface of the ceramic membrane 120, the reaction of the following formula (7) proceeds, and on the other surface of the ceramic membrane 120, the reaction of the following formula (8) proceeds, and in the entire ethylene production apparatus 102, the reaction of the following formula (9) proceeds.

[0038] 2CH 4 → C 2 H 4 +4H + +4e - … (7) O 2 +4H + +4e - → 2H 2 O … (8) 2CH 4 +O 2 → C 2 H 4 +2H 2 O … (9)

[0039] That is, in the first catalyst layer 22, a reaction in which ethylene, protons, and electrons are generated from methane supplied to the first space 24 proceeds (Equation (7)). At this time, electrons generated by the above reaction move from one surface of the ceramic film 120 to the other surface via the external circuit 42, and protons generated by the above reaction move from one surface of the ceramic film 120 to the other surface via the inside of the ceramic film 120. Further, on the other surface of the ceramic film 120, a reaction in which water is generated using oxygen supplied to the second space 26, electrons supplied via the external circuit 42, and protons supplied via the inside of the ceramic film 120 proceeds (Equation (8)). By these reactions, in the ethylene production apparatus 102, when a methane-containing gas is supplied to the first space 24 by the methane supply unit 30 and an oxygen-containing gas is supplied to the second space 26 by the oxygen supply unit 32, ethylene is generated in the first catalyst layer 22, and power is extracted from the ethylene production apparatus 102 together with ethylene.

[0040] With such a configuration, an operation of discharging protons from the first catalyst layer 22 using the ceramic film 120 having proton conductivity and an operation of moving electrons from the first catalyst layer 22 using the charge transfer unit 40 having the external circuit 42 can be continuously performed. Therefore, among the reactions included in the methane oxidative coupling reaction, the reaction of generating methyl radicals from methane can be promoted, and the efficiency of the entire reaction of generating ethylene from methane can be increased. Hereinafter, the reaction of generating methyl radicals from methane will be further described.

[0041] When the above-described methane oxidative coupling reaction proceeds, the reaction that proceeds in the first catalyst layer 22 represented by Equation (7) is considered to proceed via a plurality of reactions as shown by the following Equations (10) to (12), for example. Equation (10) shows a reaction of generating methyl radicals from methane, Equation (11) shows a reaction in which methyl radicals couple to generate ethane, similar to Equation (5) described above, and Equation (12) shows a reaction of generating ethylene from ethane.

[0042] 2CH 4 → 2·CH 3 +2H + +2e - … (10) 2·CH 3 → C 2 H 6 … (11) C 2 H 6 → C 2 H 4 +2H + +2e - … (12)

[0043] As described in the first embodiment, in the methane oxidative coupling reaction, generally, the reaction shown by the formula (10) that generates methyl radicals from methane having a stable covalent bond is considered to be the rate-determining step. The ethylene production apparatus 102 of the second embodiment uses a ceramic membrane 120 having proton conductivity, supplies methane to the first catalyst layer 22 provided on one surface of the ceramic membrane 120, supplies oxygen to the other surface of the ceramic membrane 120, and moves electrons from one surface of the ceramic membrane 20 to the other surface. Therefore, when the methane oxidative coupling reaction proceeds, protons are discharged from the first catalyst layer 22 through the ceramic membrane 20, and electrons are extracted from the first catalyst layer 22 by the charge transfer unit 40, whereby the reaction shown by the formula (10) is promoted. Thus, as a result of promoting the reaction for generating methyl radicals, which is the rate-determining step, the entire reaction for generating ethylene from methane is promoted, and the production efficiency of ethylene can be increased.

[0044] C. Third Embodiment: FIG. 3 is an explanatory diagram showing the schematic configuration of the ethylene production apparatus 103 of the third embodiment. The ethylene production apparatus 103 has the same structure as the ethylene production apparatus 101 of the first embodiment except that a second catalyst layer 28 is further provided on the other surface of the ceramic membrane 20. Hereinafter, the ceramic membrane 20, the first catalyst layer 22, and the second catalyst layer 28 are collectively referred to as a "membrane structure 23".

[0045] In the ethylene production apparatus 103 of the third embodiment, the same reactions as those in the ethylene production apparatus 101 of the first embodiment proceed. That is, in the first catalyst layer 22, the reactions represented by formulas (1) and (4) to (6) proceed, in the second catalyst layer 28, the reaction represented by formula (2) proceeds, and in the entire ethylene production apparatus 103, the reaction represented by formula (3) proceeds. The second catalyst layer 28 provided in the ethylene production apparatus 103 of the third embodiment includes a catalyst that promotes the reaction represented by formula (2). The catalyst included in the second catalyst layer 28 only needs to promote the reaction of formula (2) and is not particularly limited. As the catalyst included in the second catalyst layer 28, an oxide having oxide ion - electron mixed conductivity is preferable. For example, La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3 can be used. When such a composite oxide is used as the catalyst included in the second catalyst layer 28, such a composite oxide can be produced, for example, by the above - mentioned complex polymerization method, solid - state reaction method, coprecipitation method, or sol - gel method. Then, using the obtained catalyst, the second catalyst layer 28 may be formed on the ceramic membrane 20 in the same manner as the first catalyst layer 22.

[0046] With such a configuration, the same effects as those of the ethylene production apparatus 101 of the first embodiment can be obtained, and by providing the second catalyst layer 28, the reaction represented by formula (2) can be further promoted. As a result, the reaction of formula (3), which is the reaction proceeding in the entire ethylene production apparatus 103, can be promoted, and the production efficiency of ethylene can be further increased.

[0047] D. Fourth Embodiment: FIG. 4 is an explanatory diagram showing the schematic configuration of the ethylene production apparatus 104 of the fourth embodiment. The ethylene production apparatus 104 has the same structure as the ethylene production apparatus 102 of the second embodiment, except that a second catalyst layer 28 is further provided on the other surface of the ceramic membrane 120. Hereinafter, the ceramic membrane 120, the first catalyst layer 22, and the second catalyst layer 28 are collectively referred to as the "membrane structure 123".

[0048] In the ethylene production apparatus 104 of the fourth embodiment, the same reactions as those in the ethylene production apparatus 102 of the second embodiment proceed. That is, in the first catalyst layer 22, the reactions represented by formulas (7) and (10) to (12) proceed, in the second catalyst layer 28, the reaction represented by formula (8) proceeds, and in the entire ethylene production apparatus 103, the reaction represented by formula (9) proceeds.

[0049] The second catalyst layer 28 included in the ethylene production apparatus 104 of the fourth embodiment is provided with a catalyst that promotes the reaction represented by formula (8). The catalyst included in the second catalyst layer 28 only needs to promote the reaction of formula (8) and is not particularly limited. As the catalyst included in the second catalyst layer 28, an oxide having oxide ion - electron mixed conductivity is preferable. For example, La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3 can be used. The second catalyst layer 28 of the fourth embodiment can be produced in the same manner as the second catalyst layer 28 of the third embodiment.

[0050] With such a configuration, the same effects as those of the ethylene production apparatus 102 of the second embodiment can be obtained, and by providing the second catalyst layer 28, the reaction represented by formula (8) can be further promoted. As a result, the reaction of formula (9), which is the reaction that proceeds in the entire ethylene production apparatus 103, can be promoted, and the production efficiency of ethylene can be further increased.

[0051] E. Fifth Embodiment: FIG. 5 is an explanatory diagram showing the schematic configuration of the ethylene production apparatus 105 of the fifth embodiment. The ethylene production apparatus 105 has the same structure as the ethylene production apparatus 104 of the fourth embodiment, except that it is provided with an inert gas supply unit 34 that supplies an inert gas to the second space 26 instead of an oxygen supply unit 32 that supplies an oxygen-containing gas to the second space 26. The inert gas supplied by the inert gas supply unit 34 only needs to be a gas that does not affect the reaction proceeding on the second catalyst layer 28. For example, helium, argon, nitrogen, etc. can be used.

[0052] Note that the second catalyst layer 28 provided in the ethylene production apparatus 105 includes a catalyst that promotes the reaction of formula (14) described later, instead of the reaction of formula (8) that proceeds in the second catalyst layer 28 of the fourth embodiment. The catalyst included in the second catalyst layer 28 of the fifth embodiment only needs to promote the reaction of formula (14) and is not particularly limited. As the catalyst included in the second catalyst layer 28, an oxide having oxide ion - electron mixed conductivity is preferable. For example, La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3 can be used. The second catalyst layer 28 of the fifth embodiment can be produced in the same manner as the second catalyst layer 28 of the fourth embodiment.

[0053] In the ethylene production apparatus 105, in the first catalyst layer 22 formed on one surface of the ceramic membrane 120, the reaction of the following formula (13) (the same as the reaction of formula (7)) proceeds. On the other surface of the ceramic membrane 120, the reaction of the following formula (14) proceeds. In the entire ethylene production apparatus 102, the reaction of the following formula (15) proceeds.

[0054] 2CH 4 → C 2 H 4 +4H + +4e - … (13) 2H + +2e - → H 2 … (14) 2CH 4 → C 2 H 4 +2H 2 … (15)

[0055] That is, in the first catalyst layer 22, a reaction in which ethylene, protons, and electrons are generated from methane supplied to the first space 24 proceeds in the same manner as the reaction of formula (7) in the second and fourth embodiments (formula (13)). At this time, electrons generated in the above reaction move from one surface of the ceramic film 120 to the other surface via the external circuit 42, and protons generated in the above reaction move from one surface of the ceramic film 120 to the other surface through the inside of the ceramic film 120. Further, on the other surface of the ceramic film 120, a reaction in which hydrogen is generated proceeds using electrons supplied via the external circuit 42 and protons supplied through the inside of the ceramic film 120 (formula (14)). By supplying an inert gas to the second space 26, the hydrogen partial pressure in the second space 26 can be reduced, and the progress of the reaction of formula (14) can be maintained. By these reactions, in the ethylene production apparatus 105, when a methane-containing gas is supplied to the first space 24 by the methane supply unit 30 and an inert gas is supplied to the second space 26 by the inert gas supply unit 34, ethylene is generated in the first catalyst layer 22, and from the ethylene production apparatus 105, hydrogen and electric power are taken out together with ethylene. When the methane oxidative coupling reaction proceeds in the ethylene production apparatus 105 of the fifth embodiment, the reaction that proceeds in the first catalyst layer 22 represented by formula (13) is considered to proceed via, for example, a plurality of reactions represented by formulas (10) to (12) described above.

[0056] With such a configuration, similar to the ethylene production apparatus 104 of the fourth embodiment, the effect of enhancing the production efficiency of ethylene can be obtained. Further, according to the ethylene production apparatus 105 of the fifth embodiment, hydrogen is generated in the second catalyst layer 28 as ethylene is generated in the first catalyst layer 22. Therefore, it becomes possible to generate energy such as thermal energy and electric energy by using the obtained hydrogen as fuel for a combustion reaction or power generation, for example.

[0057] In the ethylene production apparatus 105 of the fifth embodiment shown in FIG. 5, instead of the inert gas supply unit 34, a pressure reducing unit for reducing the pressure of the second space 26 may be provided. The pressure reducing unit can be configured by, for example, a vacuum pump. Even with such a configuration, similar to the case where the inert gas supply unit 34 is provided, in the second space 26, the partial pressure of hydrogen generated in the second catalyst layer 28 can be reduced, so that the progress of the reaction of formula (14) can be maintained.

[0058] F. Sixth Embodiment: FIG. 6 is an explanatory diagram showing a schematic configuration of an ethylene production apparatus 106 of the sixth embodiment. The ethylene production apparatus 106 has the same structure as the ethylene production apparatus 104 of the fourth embodiment, except that it includes a carbon dioxide supply unit 36 that supplies a carbon dioxide-containing gas containing carbon dioxide to the second space 26 instead of the oxygen supply unit 32 that supplies an oxygen-containing gas to the second space 26.

[0059] The second catalyst layer 28 included in the ethylene production apparatus 106 is provided with a catalyst that promotes the reaction of formula (17) described later, instead of the reaction of formula (8) that proceeds in the second catalyst layer 28 of the fourth embodiment. The catalyst included in the second catalyst layer 28 of the sixth embodiment only needs to promote the reaction of formula (17) and is not particularly limited. As the catalyst included in the second catalyst layer 28, for example, nickel can be used. When nickel is used, for example, the powder of nickel oxide is made into a paste using a solvent, and this paste is applied onto the other surface of the ceramic film 120 and fired to form the second catalyst layer 28.

[0060] In the ethylene production apparatus 106, in the first catalyst layer 22 formed on one surface of the ceramic film 120, the following reaction of formula (16) (the same as the reaction of formula (7)) proceeds, on the other surface of the ceramic film 120, the following reaction of formula (17) proceeds, and in the entire ethylene production apparatus 106, the following reaction of formula (18) proceeds.

[0061] 2CH 4 → C 2 H 4 +4H+ +4e - … (16) CO 2 +8H + +8e - → CH 4 +2H 2 O … (17) 3CH 4 +CO 2 → 2C 2 H 4 +2H 2 O … (18)

[0062] That is, in the first catalyst layer 22, similar to the reaction of formula (7) in the second and fourth embodiments, a reaction in which ethylene, protons, and electrons are generated from methane supplied to the first space 24 proceeds ((formula (16))). At this time, via the external circuit 42, electrons generated in the above reaction move from one surface of the ceramic film 120 to the other surface, and protons generated in the above reaction move from one surface of the ceramic film 120 to the other surface through the inside of the ceramic film 120. Further, on the other surface of the ceramic film 120, a reaction in which methane and water are generated using carbon dioxide supplied to the second space 26, electrons supplied via the external circuit 42, and protons supplied through the inside of the ceramic film 120 proceeds ((formula (17))). By these reactions, in the ethylene production apparatus 106, when a methane-containing gas is supplied to the first space 24 by the methane supply unit 30 and carbon dioxide is supplied to the second space 26 by the carbon dioxide supply unit 36, ethylene is generated in the first catalyst layer 22, and from the ethylene production apparatus 105, ethylene, methane, and electric power are taken out. When the methane oxidative coupling reaction proceeds in the ethylene production apparatus 106 of the sixth embodiment, the reaction proceeding in the first catalyst layer 22 represented by formula (16) is considered to proceed via, for example, a plurality of reactions as shown by formulas (10) to (12) described above.

[0063] With such a configuration, similar to the ethylene production apparatus 104 of the fourth embodiment, an effect of enhancing the production efficiency of ethylene can be obtained. Further, according to the ethylene production apparatus 106 of the sixth embodiment, methane is produced in the second catalyst layer 28 as ethylene is produced in the first catalyst layer 22. Therefore, it becomes possible to generate energy by using the obtained methane as a fuel such as a combustion reaction or the like, or to use it as a material for generating other compounds.

[0064] G. Seventh Embodiment: FIG. 7 is an explanatory diagram showing a schematic configuration of an ethylene production apparatus 107 according to the seventh embodiment. The ethylene production apparatus 107 has the same structure as the ethylene production apparatus 103 of the third embodiment, except that it includes a ceramic film 220 instead of the ceramic film 20 and does not include a charge transfer unit 40 including an external circuit 42. Hereinafter, the ceramic film 220, the first catalyst layer 22, and the second catalyst layer 28 are also collectively referred to as a "membrane structure 223".

[0065] The ceramic film 220 included in the ethylene production apparatus 107 is a gas-impermeable dense film made of ceramics and is configured as a self-supporting film. Further, the ceramic film 220 contains at least one of an electron conductor and a hole conductor in addition to an oxide ion conductor, and exhibits oxide ion conductivity and at least one of electron conductivity and hole conductivity under the operating temperature and operating atmosphere of the ethylene production apparatus 107. In the following description, electron conductivity and hole conductivity are collectively referred to as "electron conductivity", and an electron conductor and a hole conductor are collectively referred to as an "electron conductor".

[0066] The ceramic film 220 can be formed, for example, by a mixture of an oxide ion conductor and an electron conductor. Alternatively, the ceramic film 220 may be formed of a composite oxide having both oxide ion conductivity and electron conductivity (hereinafter also referred to as a first mixed-conductive oxide). Alternatively, the ceramic film 220 may be formed of a mixture of at least one of an oxide ion conductor and an electron conductor and the first mixed-conductive oxide.

[0067] As the oxide ion conductor contained in the ceramic film 220, for example, the same oxide ion conductor as that of the ceramic film 20 in the first embodiment or the third embodiment may be used.

[0068] As the electron conductor contained in the ceramic film 220, for example, an oxide electron conductor having a perovskite structure, an oxide electron conductor having a spinel-type crystal structure, and an electron conductor selected from metal materials such as noble metals can be used. As the oxide electron conductor having a perovskite structure, for example, an LSM-based oxide obtained by adding Sr to the La site in a LaMnO 3 system compound, a composite oxide such as SrTiO 3 etc. can be used. Alternatively, at least one electron conductor selected from an electron conductor represented by the following formula (19) and an electron conductor represented by the following formula (20) may be used. It is desirable that the alkaline earth metal M in the formula (19) is strontium (Sr) or calcium (Ca).

[0069] La 1-x M x CrO 3 … (19) (In the formula, M is an element selected from alkaline earth metals excluding magnesium (Mg), and 0 ≦ x ≦ 0.3.)

[0070] LaCr 1-x Mg x O 3 …(20) (In the formula, 0 ≦ x ≦ 0.3.)

[0071] As the first mixed-conductive oxide included in the ceramic film 220, for example, in the LaGaO 3 system compound, an LSGF-based oxide having a perovskite structure in which Sr is added to the La site and Fe is added to the Ga site, or SrCoO 3 In the system compound, a BSCF-based oxide having a perovskite structure in which Ba is added to the Sr site and Fe is added to the Co site can be mentioned. Alternatively, as the first mixed-conductive oxide, an oxide having a layered perovskite structure, an oxide having a fluorite structure, an oxide having an oxyapatite structure, an oxide having a merilite structure, etc. can also be used.

[0072] When using the above complex oxides as the electron conductor and the first mixed-conductive oxide, such complex oxides can be produced, for example, by the previously described complex polymerization method, solid-state reaction method, coprecipitation method, or sol-gel method. Then, a mixed powder of an oxide ion conductor and an electron conductor or a powder containing the first mixed-conductive oxide is obtained, and after molding by press molding or the like, it is fired to produce the ceramic film 220.

[0073] In the ethylene production apparatus 107 of the seventh embodiment, the same reactions as those in the ethylene production apparatus 103 of the third embodiment proceed. That is, in the first catalyst layer 22, the reactions shown in equations (1) and (4) to (6) proceed, in the second catalyst layer 28, the reaction shown in equation (2) proceeds, and in the entire ethylene production apparatus 107, the reaction shown in equation (3) proceeds.

[0074] However, in the ethylene production apparatus 107 of the seventh embodiment, different from the ethylene production apparatus 103 of the third embodiment, the electrons generated in the reaction of equation (1) move to the second catalyst layer 28 through the inside of the ceramic film 220 and are used for the reaction of equation (2). Thus, in the seventh embodiment, the ceramic film 220 functions as a charge transfer part.

[0075] With such a configuration, similar to the ethylene production apparatus 103 of the third embodiment, an effect of enhancing the production efficiency of ethylene can be obtained. Further, since the charge transfer portion is constituted by the ceramic film 220 and the external circuit 42 is unnecessary, the apparatus configuration can be simplified.

[0076] H. Eighth Embodiment: FIG. 8 is an explanatory diagram showing a schematic configuration of the ethylene production apparatus 108 of the eighth embodiment. The ethylene production apparatus 108 has the same structure as the ethylene production apparatus 104 of the fourth embodiment, except that it includes a ceramic film 320 instead of the ceramic film 120 and does not include the charge transfer portion 40 including the external circuit 42. Hereinafter, the ceramic film 320, the first catalyst layer 22, and the second catalyst layer 28 are collectively referred to as a "membrane structure 323".

[0077] The ceramic film 320 included in the ethylene production apparatus 108 is a gas-impermeable dense film made of ceramics and is configured as a self-supporting film. Further, the ceramic film 320 exhibits proton conductivity and electron conductivity under the operating temperature and operating atmosphere of the ethylene production apparatus 108.

[0078] The ceramic film 320 can be formed, for example, by a mixture of a proton conductor and an electron conductor. Alternatively, the ceramic film 320 may be formed of a composite oxide having both proton conductivity and electron conductivity (hereinafter also referred to as a second mixed-conducting oxide). Alternatively, the ceramic film 320 may be formed of a mixture of at least one of a proton conductor and an electron conductor and a second mixed-conducting oxide.

[0079] As the proton conductor contained in the ceramic film 320, for example, the same proton conductor as that of the ceramic film 120 in the second and fourth to sixth embodiments may be used. Further, as the electron conductor contained in the ceramic film 320, the same electron conductor as that of the ceramic film 220 in the seventh embodiment may be used. Then, a mixed powder obtained by mixing a proton conductor and an electron conductor, or a powder containing a second mixed conductive oxide is obtained, and after being formed by press molding or the like, it is fired to produce the ceramic film 320.

[0080] In the ethylene production apparatus 108 of the eighth embodiment, the same reaction as that of the ethylene production apparatus 104 of the fourth embodiment proceeds. That is, in the first catalyst layer 22, the reactions shown in formulas (7) and (10) to (12) proceed, in the second catalyst layer 28, the reaction shown in formula (8) proceeds, and in the entire ethylene production apparatus 108, the reaction shown in formula (9) proceeds.

[0081] However, in the ethylene production apparatus 108 of the eighth embodiment, unlike the ethylene production apparatus 104 of the fourth embodiment, the electrons generated in the reaction of formula (7) move to the second catalyst layer 28 through the inside of the ceramic film 320 and are used for the reaction of formula (8). Thus, in the eighth embodiment, the ceramic film 320 functions as a charge transfer portion.

[0082] With such a configuration, similar to the ethylene production apparatus 104 of the fourth embodiment, the effect of enhancing the production efficiency of ethylene can be obtained. Further, since the charge transfer portion is constituted by the ceramic film 320 and the external circuit 42 is made unnecessary, the apparatus configuration can be simplified.

[0083] I. Ninth Embodiment: FIG. 9 is an explanatory diagram showing a schematic configuration of an ethylene production apparatus 109 according to the ninth embodiment. The ethylene production apparatus 109 has the same structure as the ethylene production apparatus 105 of the fifth embodiment, except that it includes a ceramic membrane 320 instead of the ceramic membrane 120 and does not include a charge transfer unit 40 including an external circuit 42. The ceramic membrane 320 included in the ethylene production apparatus 109 of the ninth embodiment is formed in the same manner as the ceramic membrane 320 of the eighth embodiment.

[0084] In the ethylene production apparatus 109 of the ninth embodiment, the same reactions as those in the ethylene production apparatus 105 of the fifth embodiment proceed. That is, in the first catalyst layer 22, the reaction of formula (13) (the same as the reaction of formula (7)) and the reactions shown in formulas (10) to (12) proceed, and in the second catalyst layer 28, the reaction shown in formula (14) proceeds. In the entire ethylene production apparatus 108, the reaction shown in formula (15) proceeds.

[0085] However, in the ethylene production apparatus 109 of the ninth embodiment, unlike the ethylene production apparatus 105 of the fifth embodiment, the electrons generated in the reaction of formula (13) move to the second catalyst layer 28 through the inside of the ceramic membrane 320 and are used for the reaction of formula (14). Thus, in the ninth embodiment, the ceramic membrane 320 functions as a charge transfer unit.

[0086] With such a configuration, similar to the ethylene production apparatus 105 of the fifth embodiment, the effect of enhancing the production efficiency of ethylene can be obtained. Further, since hydrogen is generated in the second catalyst layer 28 as ethylene is generated in the first catalyst layer 22, the obtained hydrogen can be used for energy generation or the like. Furthermore, since the charge transfer unit is constituted by the ceramic membrane 320 and the external circuit 42 is made unnecessary, the apparatus configuration can be simplified.

[0087] In the ethylene production apparatus 109 of the fifth embodiment shown in FIG. 9, instead of the inert gas supply unit 34, a pressure reducing unit for reducing the pressure of the second space 26 may be provided. The pressure reducing unit can be constituted by, for example, a vacuum pump. Even with such a configuration, similar to the case where the inert gas supply unit 34 is provided, in the second space 26, the partial pressure of hydrogen generated in the second catalyst layer 28 can be reduced, so that the progress of the reaction of formula (14) can be maintained.

[0088] J. Tenth Embodiment: FIG. 10 is an explanatory diagram showing a schematic configuration of the ethylene production apparatus 110 of the tenth embodiment. The ethylene production apparatus 110 has the same structure as the ethylene production apparatus 106 of the sixth embodiment, except that it includes a ceramic film 320 instead of the ceramic film 120 and does not include a charge transfer unit 40 including an external circuit 42. The ceramic film 320 provided in the ethylene production apparatus 110 of the tenth embodiment is formed in the same manner as the ceramic film 320 of the eighth embodiment.

[0089] In the ethylene production apparatus 110 of the tenth embodiment, the same reactions as those in the ethylene production apparatus 106 of the sixth embodiment proceed. That is, in the first catalyst layer 22, the reaction of formula (16) (the same as the reaction of formula (7)) and the reactions shown in formulas (10) to (12) proceed, and in the second catalyst layer 28, the reaction shown in formula (17) proceeds. In the entire ethylene production apparatus 108, the reaction shown in formula (18) proceeds.

[0090] However, in the ethylene production apparatus 110 of the tenth embodiment, different from the ethylene production apparatus 106 of the sixth embodiment, the electrons generated in the reaction of formula (16) move to the second catalyst layer 28 through the inside of the ceramic film 320 and are used for the reaction of formula (17). Thus, in the tenth embodiment, the ceramic film 320 functions as a charge transfer unit.

[0091] With such a configuration, similar to the ethylene production apparatus 106 of the sixth embodiment, the effect of enhancing the production efficiency of ethylene can be obtained. Further, according to the ethylene production apparatus 110 of the tenth embodiment, methane is produced in the second catalyst layer 28 as ethylene is produced in the first catalyst layer 22. Therefore, it becomes possible to use the obtained methane for energy generation or as a material for producing other compounds. Furthermore, since the charge transfer portion is constituted by the ceramic film 320 and the external circuit 42 is made unnecessary, the apparatus configuration can be simplified.

[0092] K. Eleventh Embodiment: FIG. 11 is an explanatory diagram showing a schematic configuration of an ethylene production apparatus 111 according to the eleventh embodiment. The ethylene production apparatus 111 has the same structure as the ethylene production apparatus 106 of the sixth embodiment, except that it further includes a methane recovery section 38.

[0093] In the ethylene production apparatus 111 of the eleventh embodiment, the same reactions as those in the ethylene production apparatus 106 of the sixth embodiment proceed. That is, in the first catalyst layer 22, the reaction of formula (16) (the same as the reaction of formula (7)) and the reactions shown in formulas (10) to (12) proceed, in the second catalyst layer 28, the reaction shown in formula (17) proceeds, and in the entire ethylene production apparatus 108, the reaction shown in formula (18) proceeds.

[0094] The methane recovery section 38 provided in the ethylene production apparatus 111 mixes the methane produced in the second catalyst layer 28 provided on the other surface of the ceramic film 120 with the methane-containing gas supplied by the methane supply section 30 to the first space 24. Specifically, the methane recovery section 38 of the eleventh embodiment is a flow path that connects an outlet section from which methane is discharged from the second space 26 of the ethylene production apparatus 111, the methane supply section 30, and the first space 24, through which the methane-containing gas flows.

[0095] With such a configuration, similar to the ethylene production apparatus 106 of the sixth embodiment, the effect of enhancing the production efficiency of ethylene can be obtained. Further, according to the ethylene production apparatus 111 of the eleventh embodiment, methane generated in the second catalyst layer 28 along with the production of ethylene in the first catalyst layer 22 is guided by the methane recovery unit 38 to the first space 24 and used for ethylene production. Therefore, compared with the case where the methane recovery unit 38 is not provided, the amount of methane to be supplied from the methane supply unit 30 for ethylene production can be reduced, and the utilization efficiency of methane can be improved.

[0096] In the ethylene production apparatus 111 of the eleventh embodiment, the methane recovery unit 38 is applied to the ethylene production apparatus 106 of the sixth embodiment, but a different configuration may be used. For example, in the ethylene production apparatus 110 of the tenth embodiment, a methane recovery unit 38 similar to that of the eleventh embodiment may be provided. Also in this case, by recovering the methane generated in the second catalyst layer 28 and supplying it to the first space 24, compared with the case where the methane recovery unit 38 is not provided, the amount of methane to be supplied from the methane supply unit 30 can be reduced, and the same effect of improving the utilization efficiency of methane can be obtained.

[0097] L. Other embodiments: Among the above-described embodiments, in the ethylene production apparatuses of the first to sixth embodiments, the charge transfer unit 40 moves electrons from one surface of the ceramic film to the other surface via the external circuit 42 by the electromotive force generated due to the potential difference between one surface and the other surface of the ceramic film, but a different configuration may be used. For example, in the charge transfer unit 40, an external power source may be connected to the external circuit 42 instead of the load unit 43. Specifically, for example, in the ethylene production apparatuses shown in FIGS. 1 to 6 and FIG. 11, an external power source may be provided instead of the load unit 43, and electrons may be moved from one surface of the ceramic film to the other surface via the external circuit 42 by the electromotive force of the external power source.

[0098] In each of the above-described embodiments, the ceramic film was a self-supporting film as shown in FIGS. 1 to 11, but it may have a different configuration. For example, the ceramic film may be a film formed on the surface of a carrier (substrate, support) made of a porous body. In this case, the ceramic film may be formed as a gas-impermeable dense film on the porous carrier by, for example, a PVD method such as the PLD method, a dip method, a thermal spraying method, a sputtering method, or the like.

Example

[0099] Hereinafter, the present disclosure will be described more specifically with reference to examples, but the present disclosure is not limited to the descriptions of these examples.

[0100] (Evaluation of Ethylene Production Apparatus) FIG. 12 is an explanatory diagram showing the results of examining the performance of 11 types of ethylene production apparatuses from Sample 1 to Sample 11. Hereinafter, the configuration and manufacturing method of each sample and the results of evaluating the performance will be described. Samples 1 to 10 each have a configuration corresponding to the ethylene production apparatuses of the first to tenth embodiments. Sample 11 is a comparative example.

[0101] (Fabrication of Membrane Structure of Each Sample) [Sample 1] As shown in FIG. 1, the ethylene production apparatus of Sample 1 includes a membrane structure 21 having a ceramic film 20 having oxide ion conductivity and a first catalyst layer 22 provided on one surface of the ceramic film 20.

[0102] The ceramic film 20 of Sample 1 was fabricated using yttria-stabilized zirconia (YSZ) as an oxide ion conductor. Specifically, TZ-8YS manufactured by Tosoh Corporation was used. The powder of the above YSZ was press-molded into a disk shape using a hydraulic press and sintered under the conditions of 1400 ° C. for 6 hours. The obtained sintered body was ground to a thickness of 0.15 mm using a surface grinding machine to obtain the ceramic film 20.

[0103] The first catalyst layer 22 of Sample 1 is BaZr as a catalyst that promotes the synthesis of ethylene from methane.0.4 Sc 0.6 O 3 was prepared using. BaZr 0.4 Sc 0.6 O 3 was prepared by the complex polymerization method as follows. As the raw material powders, barium nitrate (manufactured by Fujifilm Wako Pure Chemical Corporation), zirconyl nitrate (manufactured by Fujifilm Wako Pure Chemical Corporation), and scandium nitrate (manufactured by Alfa Aesar) were used. These raw material powders were weighed so that the ratio of the metal elements was the composition ratio in the composition formula BaZr 0.4 Sc 0.6 O 3 . Then, for the above-mentioned raw material powders, aqueous citric acid solution and propylene glycol were added so that the ratio of metal element:citric acid:propylene glycol = 1:3:3 (molar ratio), and they were stirred and mixed at 80 °C for 1 hour. Further, by slowly heating this solution to 300 °C, a polymer in which each metal element was dispersed was obtained. Further, the obtained polymer was carbonized by heat treatment at 400 °C for 2 hours, and then pulverized in an agate mortar to obtain a catalyst powder precursor. The obtained catalyst powder precursor was heat-treated at 1000 °C for 6 hours to obtain Catalyst Powder 1.

[0104] Ethyl cellulose-based binder and solvent α-terpineol were added to the obtained Catalyst Powder 1, and they were kneaded using a three-roll mill to prepare Catalyst Paste 1. This Catalyst Paste 1 was applied to one surface of the above-mentioned ceramic film 20 by screen printing with a mesh opening of 10 mm, and baked under the condition of 1000 °C for 1 hour to form the first catalyst layer 22. The film structure 21 of Sample 1 was prepared as described above.

[0105] [Sample 2] As shown in FIG. 2, the ethylene production apparatus of Sample 2 includes a membrane structure 121 having a ceramic film 120 having proton conductivity and a first catalyst layer 22 provided on one surface of the ceramic film 120.

[0106] The ceramic film 120 of Sample 2 is BaZr as a proton conductor 0.8 Y0.2 O 3 was prepared using. BaZr 0.8 Y 0.2 O 3 was prepared by the solid-state reaction method as follows. As the raw material powders, barium carbonate (manufactured by Sakai Chemical Industry Co., Ltd.), zirconium oxide (manufactured by Daiichi Kigenso Kagaku Kogyo Co., Ltd.), and yttrium oxide (manufactured by Shin-Etsu Chemical Co., Ltd.) were used. These raw material powders were weighed so that the ratio of the metal elements was the same as the composition ratio in the composition formula BaZr 0.8 Y 0.2 O 3 Then, using ZrO 2 balls (manufactured by Nikkato Corporation), they were pulverized and mixed in ethanol for 15 hours to obtain a slurry. The obtained slurry was dried by spray drying to obtain a mixed powder, and the obtained mixed powder was calcined at 1300 °C for 6 hours to obtain BaZr 0.8 Y 0.2 O 3 powder. The obtained powder was press-molded into a disk shape using a hydraulic press and sintered under the conditions of 1600 °C for 10 hours. The obtained sintered body was ground to a thickness of 0.15 mm using a surface grinding machine to obtain the ceramic film 120.

[0107] On one surface of this ceramic film 120, the first catalyst layer 22 was formed in the same manner as in Sample 1 to produce the film structure 121 of Sample 2.

[0108] [Sample 3] As shown in FIG. 3, the ethylene production apparatus of Sample 3 includes a membrane structure 23 having a ceramic film 20 having oxygen ion conductivity, a first catalyst layer 22 provided on one surface of the ceramic film 20, and a second catalyst layer 28 provided on the other surface of the ceramic film 20.

[0109] The second catalyst layer 28 of Sample 3 uses La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3 to prepare as a catalyst that promotes the reaction of formula (2). La 0.6 Sr 0.4 Co 0.2 Fe0.8 O 3 O was prepared by the solid-phase reaction method as follows. As the raw material powders, lanthanum oxide (manufactured by Fujifilm Wako Pure Chemical Corporation), strontium carbonate (manufactured by High Purity Chemical Research Institute Co., Ltd.), cobalt oxide (manufactured by High Purity Chemical Research Institute Co., Ltd.), and iron oxide (manufactured by High Purity Chemical Research Institute Co., Ltd.) were used. Using these raw material powders, catalyst paste 2 was prepared in the same manner as catalyst paste 1 of the first catalyst layer 22 described in Sample 1. Using this catalyst paste 2, a second catalyst layer 28 was formed on the other surface of a membrane structure similar to the membrane structure 21 of Sample 1 in the same manner as the first catalyst layer 22, and the membrane structure 23 of Sample 3 was prepared.

[0110] [Sample 4] As shown in FIG. 4, the ethylene production apparatus of Sample 4 includes a membrane structure 123 having a ceramic membrane 120 having proton conductivity, a first catalyst layer 22 provided on one surface of the ceramic membrane 120, and a second catalyst layer 28 provided on the other surface of the ceramic membrane 120.

[0111] The second catalyst layer 28 of Sample 4 is the same La as the second catalyst layer 28 of Sample 3 as a catalyst for promoting the reaction of formula (8) 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3 prepared using. A second catalyst layer 28 was formed on the other surface of a membrane structure 121 similar to Sample 2 in the same manner as the second catalyst layer 28 of Sample 3, and the membrane structure 123 of Sample 4 was prepared.

[0112] [Sample 5] As shown in FIG. 5, the ethylene production apparatus of Sample 5 includes a membrane structure 123 having a ceramic membrane 120 having proton conductivity, a first catalyst layer 22 provided on one surface of the ceramic membrane 120, and a second catalyst layer 28 provided on the other surface of the ceramic membrane 120.

[0113] The second catalyst layer 28 of Sample 5 was prepared using La, Sr, Co, Fe, and O, which are the same as those in the second catalyst layer 28 of Sample 3 and Sample 4, as a catalyst for promoting the reaction of formula (14). That is, the membrane structure 123 of Sample 5 has the same configuration as the membrane structure 123 of Sample 4. 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3 That is, the membrane structure 123 of Sample 5 has the same configuration as the membrane structure 123 of Sample 4.

[0114] [Sample 6] As shown in FIG. 6, the ethylene production apparatus of Sample 6 includes a membrane structure 123 having a ceramic membrane 120 having proton conductivity, a first catalyst layer 22 provided on one surface of the ceramic membrane 120, and a second catalyst layer 28 provided on the other surface of the ceramic membrane 120.

[0115] The second catalyst layer 28 of Sample 6 was prepared using nickel as a catalyst for promoting the reaction of formula (17). The second catalyst layer 28 was prepared by using nickel oxide (manufactured by High Purity Chemical Research Institute Co., Ltd.) as a raw material powder, and preparing the catalyst paste 2 of Sample 6 in the same manner as the catalyst paste 2 of Sample 3. Using this catalyst paste 2, a second catalyst layer 28 was formed on the other surface of the membrane structure 121 similar to Sample 2 in the same manner as the second catalyst layer 28 of Sample 3 to produce the membrane structure 123 of Sample 6.

[0116] [Sample 7] As shown in FIG. 7, the ethylene production apparatus of Sample 7 includes a membrane structure 223 having a ceramic membrane 220 having oxide ion conductivity and electron conductivity, a first catalyst layer 22 provided on one surface of the ceramic membrane 220, and a second catalyst layer 28 provided on the other surface of the ceramic membrane 220.

[0117] The ceramic membrane 220 of Sample 7 was prepared by mixing an oxide ion conductor and an electron conductor. As the oxide ion conductor, the same yttria-stabilized zirconia (YSZ) as the ceramic membrane 20 of Sample 1 was used. As the electron conductor, La, Sr, and CrO 0.8 Sr 0.2 CrO3 was used. La 0.8 Sr 0.2 CrO 3 was produced by the solid-phase reaction method described above, using lanthanum oxide (manufactured by Fujifilm Wako Pure Chemical Corporation), strontium carbonate (manufactured by High Purity Chemical Research Institute, Inc.), and chromium oxide (manufactured by High Purity Chemical Research Institute, Inc.) as raw material powders.

[0118] Powder of yttria-stabilized zirconia (YSZ) and powder of La 0.8 Sr 0.2 CrO 3 were weighed so that the volume ratio was YSZ:La 0.8 Sr 0.2 CrO 3 = 70:30, and using ZrO 2 balls (manufactured by Nikkato Corporation), they were pulverized and mixed in ethanol for 15 hours to obtain a slurry. The obtained slurry was spray-dried to obtain a mixed powder, and the obtained mixed powder was press-molded into a disk shape using a hydraulic press and sintered under the conditions of 1500 °C for 12 hours. The obtained sintered body was ground to a thickness of 0.15 mm using a surface grinding machine to obtain a ceramic film 220. On one surface of this ceramic film 220, the first catalyst layer 22 described above was formed, and on the other surface of the ceramic film 220, a second catalyst layer 28 similar to the second catalyst layer 28 of Sample 3 was formed to produce a film structure 223 of Sample 7.

[0119] [Sample 8] As shown in FIG. 8, the ethylene production apparatus of Sample 8 includes a membrane structure 323 having a ceramic film 320 having both proton conductivity and electron conductivity, a first catalyst layer 22 provided on one surface of the ceramic film 320, and a second catalyst layer 28 provided on the other surface of the ceramic film 320.

[0120] The ceramic film 320 of Sample 8 was produced by mixing a proton conductor and an electron conductor. As the proton conductor, BaZr similar to the ceramic film 120 of Sample 2 0.8 Y 0.2 O 3was used. As the electronic conductor, La similar to the ceramic film 220 of Sample 7 0.8 Sr 0.2 CrO 3 was used.

[0121] BaZr 0.8 Y 0.2 O 3 powder and La 0.8 Sr 0.2 CrO 3 powder were weighed so that the volume ratio was BaZr 0.8 Y 0.2 O 3 :La 0.8 Sr 0.2 CrO 3 = 70:30, and a sintered body was obtained and ground in the same manner as in Sample 7 to obtain a ceramic film 320. On one surface of this ceramic film 320, the above-described first catalyst layer 22 was formed, and on the other surface of the ceramic film 320, a second catalyst layer 28 similar to the second catalyst layer 28 of Sample 4 was formed to fabricate a film structure 323 of Sample 8.

[0122] [Sample 9] As shown in FIG. 9, the ethylene production apparatus of Sample 9 includes a film structure 323 having a ceramic film 320 having both proton conductivity and electronic conductivity, a first catalyst layer 22 provided on one surface of the ceramic film 320, and a second catalyst layer 28 provided on the other surface of the ceramic film 320.

[0123] The ceramic film 320 of Sample 9 was fabricated in the same manner as the ceramic film 320 of Sample 8. On one surface of this ceramic film 320, the above-described first catalyst layer 22 was formed, and on the other surface of the ceramic film 320, a second catalyst layer 28 similar to the second catalyst layer 28 of Sample 5 was formed to fabricate a film structure 323 of Sample 9.

[0124] [Sample 10] As shown in Fig. 10, the ethylene production apparatus of Sample 10 includes a membrane structure 323 having a ceramic membrane 320 having both proton conductivity and electron conductivity, a first catalyst layer 22 provided on one surface of the ceramic membrane 320, and a second catalyst layer 28 provided on the other surface of the ceramic membrane 320.

[0125] The ceramic membrane 320 of Sample 10 was produced in the same manner as the ceramic membranes 320 of Sample 8 and Sample 9. The first catalyst layer 22 described above was formed on one surface of the ceramic membrane 320, and a second catalyst layer 28 similar to the second catalyst layer 28 of Sample 6 was formed on the other surface of the ceramic membrane 320 to produce the membrane structure 323 of Sample 10.

[0126] [Sample 11] In the ethylene production apparatus of Sample 11, only the methane oxidative coupling catalyst is used without using a ceramic membrane. As the methane oxidative coupling catalyst of Sample 11, the catalyst powder 1 produced for forming the first catalyst layer 22 of Sample 1 was used.

[0127] <C of Samples 1 to 10 2 Measurement of Yield Fig. 13 is an explanatory diagram showing the schematic configuration of a measuring device 50 for measuring the C 2 yield in the ethylene production apparatuses of Samples 1 to 10. In Fig. 13, as an example, the state of measurement using the membrane structure 21 of Sample 1 is shown, but the measuring devices of other samples have the same configuration.

[0128] The measuring device 50 includes two outer alumina tubes 53 and 55, two inner alumina tubes 52 and 54, and an electric furnace 56. The two outer alumina tubes 53 and 55 are arranged vertically, and measurements are taken with the membrane structure of each sample sandwiched therebetween. When joining the outer alumina tubes 53 and 55 to the membrane structure, on the outer peripheral portion of the membrane structure where the ceramic membrane is exposed without being covered by the catalyst layer, thin film rings 51 of gold with an inner diameter of 10 mm are placed on both surfaces of the ceramic membrane. Then, the outer alumina tubes 53 and 55 are pressed against the ceramic membrane via the thin film rings 51, the temperature is raised to 1050 °C to soften the gold, and gas tightness is ensured. An inner alumina tube 52 is arranged inside the outer alumina tube 53, and an inner alumina tube 54 is arranged inside the outer alumina tube 55. The space above the membrane structure in the outer alumina tube 53 is the first space 24, and the space above the membrane structure in the outer alumina tube 55 is the second space 26. The outer alumina tubes 53 and 55 with the membrane structure attached are arranged in the electric furnace 56 such that the membrane structure is disposed in the isothermal portion of the electric furnace 56.

[0129] In each of the measuring devices 50 of the respective samples assembled as described above, in the first space 24, methane was supplied at a flow rate of 10 cm 3 / min via the inner alumina tube 52. The gas containing ethylene generated by the methane oxidative coupling reaction proceeding in the first catalyst layer 22 was discharged from the first space 24 through the flow path between the inner alumina tube 52 and the outer alumina tube 53 and out through the first discharge flow path 57. For the second space 26, the gas shown in FIG. 12 was supplied via the inner alumina tube 54. The gas that has undergone the reaction proceeding on the surface exposed in the second space 26 of the membrane structure was discharged from the second space 26 through the flow path between the inner alumina tube 54 and the outer alumina tube 55 and out through the second discharge flow path 58.

[0130] Also, the temperature of the electric furnace 56 was set to 700 °C. Although not shown in FIG. 13, external circuits 42 were provided for the measuring devices 50 of Samples 1 to 6, and a DC electronic load device (manufactured by Takasago Seisakusho Co., Ltd., FK-160L2Z) was used to set the current density to 0.25 A / cm 2was carried out. The analysis of the gas discharged from the first space 24 and the gas discharged from the second space 26 was performed using micro gas chromatography (manufactured by Agilent Technologies, 3000A), and C 2 yield was determined. The obtained C 2 yield is shown in accordance with FIG. 12. The gas discharged from the first space 24 contains ethane generated by the formula (5) or (11) in addition to ethylene. Usually, since the reactions of the formulas (6) and (12) further proceed, most of the obtained C 2 hydrocarbons are ethylene (data not shown).

[0131] <Yield measurement of Sample 11 2 > In the ethylene production apparatus of Sample 11, 0.1 g of the catalyst powder 1 described in Sample 1 was weighed and placed in a fixed-bed flow-type reactor. While heated to 700 °C, a mixed gas of methane, oxygen, and nitrogen was set to CH 4 :O 2 :N 2 = 3.8:1:4, and a catalytic activity test was carried out by flowing it at 1 atm and 45 cm 3 / min. The composition analysis of the gas introduced into the apparatus and the discharged gas was performed using micro gas chromatography (manufactured by Agilent Technologies, 3000A). As a result of the composition analysis, the obtained C 2 yield is shown in accordance with FIG. 12.

[0132] As shown in FIG. 12, the ethylene production apparatuses of Samples 1 to 10 including the ceramic membrane 20, the first catalyst layer 22, and the charge transfer part 40 showed a higher C 2 yield than the ethylene production apparatus of Sample 11 using a fixed-bed flow-type reactor. In particular, as can be seen by comparing Sample 1 and Sample 3, or Sample 2 and Sample 4, it was confirmed that the C 2 yield was improved by further providing the second catalyst layer 28.

[0133] (Evaluation of Methane Oxidation Coupling Catalyst) Figures 14 and 15 are explanatory diagrams showing the results of examining the performance of 34 types of methane oxidation coupling catalysts from Sample 21 to Sample 54. Below, the composition and manufacturing method of each sample and the results of evaluating the performance will be described.

[0134] <Preparation of Each Sample> [Sample 21] The catalyst of Sample 21 (BaZr 0.8 Sc 0.2 O 3 ) was prepared by the complex polymerization method. As raw material powders, barium nitrate (manufactured by Fujifilm Wako Pure Chemical Corporation), zirconyl nitrate (manufactured by Fujifilm Wako Pure Chemical Corporation), and scandium nitrate (manufactured by Alfa Aesar) were used. These raw material powders were weighed so that the ratio of metal elements became the composition ratio in the composition formula BaZr 0.8 Sc 0.2 O 3 . Then, citric acid aqueous solution and propylene glycol were added to the above-mentioned raw material powders so that the ratio of metal element:citric acid:propylene glycol = 1:3:3 (mol ratio), and they were stirred and mixed at 80°C for 1 hour. Further, by slowly heating this solution to 300°C, a polymer in which each metal element was dispersed was obtained. Further, the obtained polymer was carbonized by heat treatment at 400°C for 2 hours, and was pulverized in an agate mortar to obtain a catalyst powder precursor. The obtained catalyst powder precursor was heat-treated at 1200°C for 6 hours to obtain catalyst powder 21.

[0135] [Samples 22 to 54] The types of the raw material powders of the catalyst and the weighed amounts were adjusted to the composition ratios of the composition formulas of Samples 22 to 54 shown in FIGS. 14 and 15, and the heat treatment temperature of the catalyst powder precursor was set to the temperature shown in FIGS. 14 and 15. Catalyst powders 22 to 54 were obtained in the same manner as Sample 21 except for this. In order to add each of barium, zirconium, scandium, yttrium, ytterbium, indium, neodymium, cerium, lanthanum, strontium, calcium, iron, and titanium as constituent elements, barium nitrate (manufactured by Fujifilm Wako Pure Chemical Corporation), zirconyl nitrate (manufactured by Fujifilm Wako Pure Chemical Corporation), scandium nitrate (manufactured by Alfa Aesar), yttrium nitrate (manufactured by Sigma-Aldrich), ytterbium nitrate (manufactured by Sigma-Aldrich), indium nitrate (manufactured by Fujifilm Wako Pure Chemical Corporation), neodymium nitrate (manufactured by Fujifilm Wako Pure Chemical Corporation), cerium nitrate (manufactured by Fujifilm Wako Pure Chemical Corporation), lanthanum nitrate (manufactured by Fujifilm Wako Pure Chemical Corporation), strontium nitrate (manufactured by Fujifilm Wako Pure Chemical Corporation), calcium nitrate (manufactured by Fujifilm Wako Pure Chemical Corporation), iron nitrate (manufactured by Sigma-Aldrich), and tetra-i-propoxytitanium (manufactured by High Purity Chemical Research Institute Co., Ltd.) were used for the raw material powders.

[0136] <C 2 Measurement of Yield> 0.1 g of each of the catalyst powders 21 to 54 was weighed and placed in a fixed-bed flow-type reactor, and while heated to 750° C., a mixed gas of methane, oxygen, and nitrogen was flowed at a flow rate ratio of CH 4 :O 2 :N 2 =3.8:1:4 at 1 atm and 45 cm 3 / min to conduct a catalyst activity test. The composition analysis of the gas introduced into the apparatus and the discharged gas was performed using a micro gas chromatograph (manufactured by Agilent Technologies, 3000A). As a result of the composition analysis, the obtained C 2 yield is shown in FIGS. 14 and 15.

[0137] <Measurement of Total Conductivity> Each of the catalyst powders 21 to 54 was press-molded into a rectangular parallelepiped, sintered under the conditions of 1600 °C for 6 hours, and after a platinum wire was wound around at four locations, a platinum paste (manufactured by Tanaka Kikinzoku Kogyo K.K., TR-7905) was applied thereon, baked under the conditions of 1000 °C for 1 hour, and used as a measurement sample. Each measurement sample was placed in a tubular electric furnace, heated in a state where hydrogen humidified by a bubbler was circulated, and the total conductivity was measured at 750 °C by the four-terminal AC method.

[0138] <Measurement of Proton Transport Rate and Electron / Hole Transport Rate> Each of the catalyst powders 21 to 54 was press-molded into a disk shape, and platinum paste was screen-printed circularly on both sides of the sintered product under the conditions of 1600 °C for 6 hours, and baked under the conditions of 1000 °C for 1 hour to prepare a measurement sample. The transport rate measuring device includes two alumina tubes arranged vertically with their axial directions aligned. Then, each of the above-described measurement samples was sandwiched between the two alumina tubes, the gas sealability between the alumina tube and the measurement sample was ensured, and the portion including the measurement sample was placed in an electric furnace to measure the transport rate. Specifically, in the spaces inside the two alumina tubes, while humidified hydrogen with different concentrations or humidification amounts was circulated in one space and the other space separated by the measurement sample, it was heated to 750 °C using the above electric furnace. Then, by measuring the electromotive force generated between one surface and the other surface of the measurement sample, the proton transport rate and the electron / hole transport rate (the sum of the electron transport rate and the hole transport rate) were determined.

[0139] <Derivation of Proton Conductivity> The proton conductivity was calculated by multiplying the total conductivity measured as described above by the proton transport rate.

[0140] Among the samples shown in FIGS. 14 and 15, the catalysts of Samples 21 to 49 satisfy the following conditions. That is, the general formula (A 1-x A' x )(Zr 1-y-z B y B' z )O 3(However, A is at least one element selected from alkaline earth metals, A' is at least one element selected from lanthanum (La) and yttrium (Y), B is at least one element selected from titanium (Ti) and cerium (Ce), and B' is at least one element selected from yttrium (Y), scandium (Sc), ytterbium (Yb), aluminum (Al), indium (In), and neodymium (Nd)), having a perovskite structure represented by the following, where x, y, and z satisfy 0 ≦ x ≦ 0.4, 0.3 ≦ (1 - z) ≦ 1, 0 ≦ y, 0 < (1 - y - z), are satisfied.

[0141] As shown in FIGS. 14 and 15, the catalysts of Samples 21 to 49 showed higher C 2 yields than the catalysts of Samples 50 to 54 as comparative examples that do not satisfy the above conditions. Therefore, it is considered that the performance of the ethylene production apparatus can be enhanced by applying the catalyst that satisfies the above-described conditions to the first catalyst layer 22 provided in the ethylene production apparatus according to the first to eleventh embodiments.

[0142] Furthermore, among the catalysts of Samples 21 to 49, Samples 21 to 24, 26 to 32, 35 to 37, 39, 40, 42 to 44, 46 to 49 have a proton conductivity of 1.0×10 -4It showed a relatively high value of S / cm or more. Among the catalysts of Samples 21 to 49, Samples 21 to 44 and 46 to 49 had a proton transport rate of 0.01 or more. Among the catalysts of Samples 21 to 49, Samples 21 to 40, 42 to 44, and 46 to 49 had a total of the electron transport rate and the hole transport rate of 0.01 or more and 0.95 or less. Among the catalysts of Samples 21 to 49, Samples 21 to 32, 35 to 37, 39, 40, 43, 44, and 46 to 49 had a proton transport rate and a total of the electron transport rate and the hole transport rate of 0.10 or more, respectively. By applying such a catalyst to the first catalyst layer 22 of the ethylene production apparatus in each embodiment where the first catalyst layer 22 conducts proton and electron transfer, it is considered that the performance of the ethylene production apparatus can be further enhanced.

[0143] The present disclosure is not limited to the above-described embodiments and the like, and can be realized in various configurations without departing from the gist thereof. For example, the technical features in the embodiments corresponding to the technical features in each form described in the summary of the invention can be appropriately replaced or combined in order to solve part or all of the above-described problems or to achieve part or all of the above-described effects. Further, if the technical feature is not described as essential in this specification, it can be appropriately deleted.

Explanation of Reference Numerals

[0144] 20, 120, 220, 320... ceramic film 21, 23, 121, 123, 223, 323... film structure 22... first catalyst layer 24... first space 26... second space 28... second catalyst layer 30... methane supply section 32... oxygen supply section 34... inert gas supply section 36... carbon dioxide supply section 38... methane recovery section 40... charge transfer section 42... external circuit 43... load section 50…Measuring device 51…Thin film ring 52, 54…Inner alumina tube 53, 55…Outer alumina tube 56…Electric furnace 57…First discharge flow path 58…Second discharge flow path 101~111…Ethylene production device

Claims

1. An ethylene production apparatus for producing ethylene from a methane-containing gas, comprising: a ceramic membrane having at least one of oxide ion conductivity and proton conductivity; a first catalyst layer provided on one surface of the ceramic membrane and comprising a catalyst that promotes a methane oxidative coupling reaction for producing ethylene from methane; a methane supply unit for supplying the methane-containing gas to a space on the one surface side of the ceramic membrane among two spaces separated by the ceramic membrane; a charge transfer unit for moving electrons from one surface of the ceramic membrane to the other surface, or for moving holes from the other surface of the ceramic membrane to the one surface; an oxygen supply unit for supplying an oxygen-containing gas containing oxygen to a space on the other surface side of the ceramic membrane; and comprising: the charge transfer unit comprises an external circuit connecting the one surface and the other surface of the ceramic membrane, and electrons are moved from the one surface to the other surface of the ceramic membrane through the external circuit by an electromotive force generated due to a potential difference between the one surface and the other surface of the ceramic membrane; when the methane-containing gas is supplied to the space on the one surface side by the methane supply unit, ethylene is generated in the first catalyst layer. Ethylene production apparatus.

2. The ethylene production apparatus according to claim 1, wherein: the ceramic membrane has oxide ion conductivity; the ethylene production apparatus further comprises a second catalyst layer provided on the other surface of the ceramic membrane and comprising a catalyst that promotes a reaction for generating oxide ions from oxygen. Ethylene production apparatus.

3. The ethylene production apparatus according to claim 1, wherein: the ceramic membrane has proton conductivity; the ethylene production apparatus further comprises a second catalyst layer provided on the other surface of the ceramic membrane and comprising a catalyst that promotes a reaction using oxygen and protons. Ethylene production apparatus.

4. An ethylene production apparatus for producing ethylene from a methane-containing gas, comprising: a ceramic membrane having at least one of oxide ion conductivity and proton conductivity; A first catalyst layer provided on one surface of the ceramic membrane and comprising a catalyst that promotes the methane oxidative coupling reaction for producing ethylene from methane; A methane supply unit that supplies the methane-containing gas to the space on the one surface side of the ceramic membrane among the two spaces separated by the ceramic membrane; A charge transfer unit that moves electrons from one surface of the ceramic membrane to the other surface, or moves holes from the other surface of the ceramic membrane to the one surface; An inert gas supply unit that supplies an inert gas to the space on the other surface side of the ceramic membrane, or a pressure reducing unit that reduces the pressure of the space on the other surface side of the ceramic membrane; A second catalyst layer provided on the other surface of the ceramic membrane and comprising a catalyst that promotes the reaction for producing hydrogen from protons; Comprising; The ceramic membrane has proton conductivity; The charge transfer unit includes an external circuit connecting the one surface and the other surface of the ceramic membrane, and electrons are moved from the one surface of the ceramic membrane to the other surface through the external circuit by an electromotive force generated due to the potential difference between the one surface and the other surface of the ceramic membrane; When the methane-containing gas is supplied to the space on the one surface side by the methane supply unit, ethylene is produced in the first catalyst layer. Ethylene production apparatus.

5. An ethylene production apparatus for producing ethylene from a methane-containing gas, comprising: A ceramic membrane having at least one of oxide ion conductivity and proton conductivity; A first catalyst layer provided on one surface of the ceramic membrane and comprising a catalyst that promotes the methane oxidative coupling reaction for producing ethylene from methane; A methane supply unit that supplies the methane-containing gas to the space on the one surface side of the ceramic membrane among the two spaces separated by the ceramic membrane; A charge transfer unit that moves electrons from one surface of the ceramic membrane to the other surface, or moves holes from the other surface of the ceramic membrane to the one surface; A carbon dioxide supply unit that supplies a carbon dioxide-containing gas containing carbon dioxide to the space on the other surface side of the ceramic membrane; A second catalyst layer provided on the other surface of the ceramic film and including a catalyst that promotes a reaction for generating methane using carbon dioxide and protons. Comprising: The ceramic film has proton conductivity. The charge transfer part includes an external circuit that connects the one surface and the other surface of the ceramic film, and electrons are moved from the one surface of the ceramic film to the other surface through the external circuit due to the electromotive force generated by the potential difference between the one surface and the other surface of the ceramic film. When the methane-containing gas is supplied to the space on the one surface side by the methane supply part, ethylene is generated in the first catalyst layer. An ethylene production apparatus. **Claim 6** An ethylene production apparatus for producing ethylene from a methane-containing gas, A ceramic film having at least one of oxide ion conductivity and proton conductivity, A first catalyst layer provided on one surface of the ceramic film and including a catalyst that promotes a methane oxidative coupling reaction for generating ethylene from methane, A methane supply part that supplies the methane-containing gas to the space on the one surface side of the two spaces separated by the ceramic film, A charge transfer part that moves electrons from the one surface to the other surface of the ceramic film, or moves holes from the other surface to the one surface of the ceramic film, An oxygen supply part that supplies an oxygen-containing gas containing oxygen to the space on the other surface side of the ceramic film, A second catalyst layer provided on the other surface of the ceramic film and including a catalyst that promotes a reaction for generating oxide ions from oxygen, Comprising: The ceramic film has oxide ion conductivity and at least one of electron conductivity and hole conductivity. The charge transfer part is the ceramic film, and electrons are moved from the one surface to the other surface, or holes are moved from the other surface to the one surface inside the charge transfer part itself as ethylene is generated on the one surface of the ceramic film. When the methane-containing gas is supplied to the space on the one surface side by the methane supply part, ethylene is generated in the first catalyst layer. An ethylene production apparatus. **Claim 7** An ethylene production apparatus for producing ethylene from a methane-containing gas, a ceramic membrane having at least one of oxide ion conductivity and proton conductivity, a first catalyst layer provided on one surface of the ceramic membrane and including a catalyst that promotes a methane oxidative coupling reaction for producing ethylene from methane, a methane supply unit that supplies the methane-containing gas to the space on the one surface side of the ceramic membrane among the two spaces separated by the ceramic membrane, a charge transfer unit that moves electrons from the one surface to the other surface of the ceramic membrane or moves holes from the other surface to the one surface of the ceramic membrane, an inert gas supply unit that supplies an inert gas to the space on the other surface side of the ceramic membrane, or a pressure reducing unit that reduces the pressure of the space on the other surface side of the ceramic membrane, a second catalyst layer provided on the other surface of the ceramic membrane and including a catalyst that promotes a reaction for generating hydrogen from protons, comprising: the ceramic membrane further has at least one of electron conductivity and hole conductivity in addition to proton conductivity, the charge transfer unit is the ceramic membrane, and with the generation of ethylene on the one surface of the ceramic membrane, electrons are moved from the one surface to the other surface or holes are moved from the other surface to the one surface inside itself, characterized in that ethylene is generated in the first catalyst layer when the methane-containing gas is supplied to the space on the one surface side by the methane supply unit. Ethylene production apparatus. **Claim 8** An ethylene production apparatus for producing ethylene from a methane-containing gas, a ceramic membrane having at least one of oxide ion conductivity and proton conductivity, a first catalyst layer provided on one surface of the ceramic membrane and including a catalyst that promotes a methane oxidative coupling reaction for producing ethylene from methane, a methane supply unit that supplies the methane-containing gas to the space on the one surface side of the ceramic membrane among the two spaces separated by the ceramic membrane, a charge transfer unit that moves electrons from the one surface to the other surface of the ceramic membrane or moves holes from the other surface to the one surface of the ceramic membrane, A carbon dioxide supply unit that supplies a carbon dioxide-containing gas containing carbon dioxide to the space on the other surface side of the ceramic membrane; A second catalyst layer provided on the other surface of the ceramic membrane and including a catalyst that promotes a reaction for generating methane using carbon dioxide and protons; A methane recovery unit that mixes the methane generated on the other surface of the ceramic membrane with the methane-containing gas supplied by the methane supply unit to the space on the one surface side of the ceramic membrane; Comprising; The ceramic membrane has proton conductivity; The charge transfer unit includes an external circuit that connects the one surface and the other surface of the ceramic membrane, and electrons are moved from the one surface of the ceramic membrane to the other surface through the external circuit by an electromotive force generated due to a potential difference between the one surface and the other surface of the ceramic membrane; When the methane-containing gas is supplied to the space on the one surface side by the methane supply unit, ethylene is generated in the first catalyst layer. Ethylene production apparatus.

9. An ethylene production apparatus for producing ethylene from a methane-containing gas, comprising: A ceramic membrane having at least one of oxide ion conductivity and proton conductivity; A first catalyst layer provided on one surface of the ceramic membrane and including a catalyst that promotes a methane oxidative coupling reaction for generating ethylene from methane; A methane supply unit that supplies the methane-containing gas to the space on the one surface side of the ceramic membrane among two spaces separated by the ceramic membrane; A charge transfer unit that moves electrons from the one surface to the other surface of the ceramic membrane, or moves holes from the other surface to the one surface of the ceramic membrane; A carbon dioxide supply unit that supplies a carbon dioxide-containing gas containing carbon dioxide to the space on the other surface side of the ceramic membrane; A second catalyst layer provided on the other surface of the ceramic membrane and including a catalyst that promotes a reaction for generating methane using carbon dioxide and protons; A methane recovery unit that mixes the methane generated on the other surface of the ceramic membrane with the methane-containing gas supplied by the methane supply unit to the space on the one surface side of the ceramic membrane; Comprising; In addition to proton conductivity, the ceramic film further has at least one of electron conductivity and hole conductivity. The charge transfer part is the ceramic film, and with the generation of ethylene on one surface of the ceramic film, electrons are moved from the one surface to the other surface within itself, or holes are moved from the other surface to the one surface. When the methane-containing gas is supplied to the space on the one surface side by the methane supply part, ethylene is produced in the first catalyst layer. Ethylene production apparatus.

10. An ethylene production apparatus according to any one of Claims 1 to 9, wherein the catalyst provided in the first catalyst layer is General formula (A １－ｘ A' ｘ )(Zr １－ｙ－ｚ B ｙ B' ｚ )O ３ (wherein A is at least one element selected from alkaline earth metals, A' is at least one element selected from lanthanum (La) and yttrium (Y), B is at least one element selected from titanium (Ti) and cerium (Ce), and B' is at least one element selected from yttrium (Y), scandium (Sc), ytterbium (Yb), aluminum (Al), indium (In), and neodymium (Nd)), having a perovskite structure, and x, y, and z are 0 ≤ x ≤ 0.4, 0.3 ≤ (1 - z) ≤ 1, 0 ≤ y, 0 < (1 - y - z), characterized in that it satisfies the above conditions.

11. An ethylene production method for producing ethylene from a methane-containing gas, in one of two spaces separated by a ceramic film having at least one of oxide ion conductivity and proton conductivity, in the space on one surface side of the ceramic film provided with a first catalyst layer including a catalyst that promotes a methane oxidative coupling reaction for generating ethylene from methane, the methane-containing gas is supplied, an oxygen-containing gas containing oxygen is supplied to the space on the other surface side of the ceramic film, due to the electromotive force generated by the potential difference between the one surface of the ceramic film and the other surface of the ceramic film, electrons are moved from the one surface of the ceramic film to the other surface through an external circuit connecting the one surface and the other surface of the ceramic film, so that charge transfer is performed between the one surface and the other surface, in the first catalyst layer, ethylene is generated from methane in the methane-containing gas. Ethylene production method.

12. An ethylene production method according to Claim 11, characterized in that as the ceramic film, a film having oxide ion conductivity and provided with a second catalyst layer including a catalyst that promotes a reaction for generating oxide ions from oxygen on the other surface is used. Ethylene production method.

13. An ethylene production method according to Claim 11, As the ceramic film, a film having proton conductivity, and a second catalyst layer including a catalyst that promotes a reaction using oxygen and protons is provided on the other surface thereof. Ethylene production method.

14. An ethylene production method for producing ethylene from a methane-containing gas, In one of two spaces separated by a ceramic film having at least one of oxide ion conductivity and proton conductivity, in a space on one surface side of the ceramic film where a first catalyst layer including a catalyst that promotes a methane oxidative coupling reaction that produces ethylene from methane is provided on the ceramic film, the methane-containing gas is supplied, Supply of an inert gas to the space on the other surface side of the ceramic film, or depressurization of the space on the other surface side of the ceramic film is performed, As the ceramic film, a film having proton conductivity, and a second catalyst layer including a catalyst that promotes a reaction for generating hydrogen from protons is provided on the other surface thereof. A film is used, Due to the electromotive force generated by the potential difference between the one surface and the other surface of the ceramic film, electrons are moved from the one surface to the other surface of the ceramic film through an external circuit connecting the one surface and the other surface of the ceramic film, thereby causing charge transfer between the one surface and the other surface, In the first catalyst layer, ethylene is produced from methane in the methane-containing gas. Ethylene production method.

15. An ethylene production method for producing ethylene from a methane-containing gas, In one of two spaces separated by a ceramic film having at least one of oxide ion conductivity and proton conductivity, in a space on one surface side of the ceramic film where a first catalyst layer including a catalyst that promotes a methane oxidative coupling reaction that produces ethylene from methane is provided on the ceramic film, the methane-containing gas is supplied, A carbon dioxide-containing gas containing carbon dioxide is supplied to the space on the other surface side of the ceramic film, As the ceramic film, a film having proton conductivity, and a second catalyst layer including a catalyst that promotes a reaction for generating methane using carbon dioxide and protons is provided on the other surface thereof. A film is used, Due to the electromotive force generated by the potential difference between one surface of the ceramic film and the other surface of the ceramic film, electrons are moved from one surface of the ceramic film to the other surface through an external circuit connecting the one surface and the other surface of the ceramic film, causing the movement of charges between the one surface and the other surface, characterized in that ethylene is produced from methane in the methane-containing gas in the first catalyst layer. Ethylene production method.

16. An ethylene production method for producing ethylene from a methane-containing gas, in one of two spaces separated by a ceramic film having at least one of oxide ion conductivity and proton conductivity, in a space on one surface side of the ceramic film provided with a first catalyst layer having a catalyst that promotes a methane oxidative coupling reaction for producing ethylene from methane, the methane-containing gas is supplied, an oxygen-containing gas containing oxygen is supplied to the space on the other surface side of the ceramic film, as the ceramic film, a film having oxide ion conductivity and at least one of electron conductivity and hole conductivity, and provided with a second catalyst layer having a catalyst that promotes a reaction for generating oxide ions from oxygen on the other surface is used, with the generation of ethylene on one surface of the ceramic film, electrons are moved from the one surface to the other surface or holes are moved from the other surface to the one surface inside the ceramic film, causing the movement of charges between the one surface and the other surface, characterized in that ethylene is produced from methane in the methane-containing gas in the first catalyst layer. Ethylene production method.

17. An ethylene production method for producing ethylene from a methane-containing gas, in one of two spaces separated by a ceramic film having at least one of oxide ion conductivity and proton conductivity, in a space on one surface side of the ceramic film provided with a first catalyst layer having a catalyst that promotes a methane oxidative coupling reaction for producing ethylene from methane, the methane-containing gas is supplied, Supply an inert gas to the space on the other side of the ceramic film, or reduce the pressure in the space on the other side of the ceramic film. As the ceramic film, use a film having at least one of electron conductivity and hole conductivity in addition to proton conductivity, and provide a second catalyst layer on the other surface, the second catalyst layer including a catalyst that promotes a reaction for generating hydrogen from protons. With the generation of ethylene on one surface of the ceramic film, cause charge transfer between the one surface and the other surface by moving electrons from the one surface to the other surface or moving holes from the other surface to the one surface inside the ceramic film. In the first catalyst layer, ethylene is produced from methane in the methane-containing gas. Ethylene production method.

18. An ethylene production method for producing ethylene from a methane-containing gas, In one of two spaces separated by a ceramic film having at least one of oxide ion conductivity and proton conductivity, in the space on one surface side of the ceramic film where a first catalyst layer including a catalyst that promotes a methane oxidative coupling reaction for generating ethylene from methane is provided on the ceramic film, supply the methane-containing gas. Supply a carbon dioxide-containing gas containing carbon dioxide to the space on the other surface side of the ceramic film. As the ceramic film, use a film having proton conductivity, and provide a second catalyst layer on the other surface, the second catalyst layer including a catalyst that promotes a reaction for generating methane using carbon dioxide and protons. Due to the electromotive force generated by the potential difference between the one surface and the other surface of the ceramic film, cause charge transfer between the one surface and the other surface by moving electrons from the one surface to the other surface of the ceramic film through an external circuit connecting the one surface and the other surface of the ceramic film. In the first catalyst layer, produce ethylene from methane in the methane-containing gas. Mix the methane generated on the other surface of the ceramic film with the methane-containing gas supplied to the space on the one surface side of the ceramic film. Ethylene production method.

19. An ethylene production method for producing ethylene from a methane-containing gas, in one of two spaces separated by a ceramic membrane having at least one of oxide ion conductivity and proton conductivity, a first catalyst layer provided on the ceramic membrane and comprising a catalyst that promotes a methane oxidative coupling reaction for generating ethylene from methane is provided in the space on one surface side of the ceramic membrane, and the methane-containing gas is supplied thereto, a carbon dioxide-containing gas containing carbon dioxide is supplied to the space on the other surface side of the ceramic membrane, as the ceramic membrane, a membrane having at least one of electron conductivity and hole conductivity in addition to proton conductivity, and a second catalyst layer provided on the other surface and comprising a catalyst that promotes a reaction for generating methane using carbon dioxide and protons is used, with the generation of ethylene on the one surface of the ceramic membrane, electrons are moved from the one surface to the other surface or holes are moved from the other surface to the one surface inside the ceramic membrane, thereby causing charge transfer between the one surface and the other surface, ethylene is generated from methane in the methane-containing gas in the first catalyst layer, the methane generated on the other surface of the ceramic membrane is mixed with the methane-containing gas supplied to the space on the one surface side of the ceramic membrane, and an ethylene production method is characterized thereby.

20. The ethylene production method according to any one of claims 11 to 19, as the catalyst comprised in the first catalyst layer, General formula (A １－ｘ A' ｘ )(Zr １－ｙ－ｚ B ｙ B' ｚ )O ３ (However, A is at least one element selected from alkaline earth metals, A' is at least one element selected from lanthanum (La) and yttrium (Y), B is at least one element selected from titanium (Ti) and cerium (Ce), and B' is at least one element selected from yttrium (Y), scandium (Sc), ytterbium (Yb), aluminum (Al), indium (In), and neodymium (Nd)), having a perovskite structure, where the x, the y, and the z are 0 ≦ x ≦ 0.4, 0.3 ≦ (1 - z) ≦ 1, 0 ≦ y, 0 < (1 - y - z), and a catalyst satisfying the above is used, and an ethylene production method is characterized thereby.

Images