Method for producing a mixed gas, catalyst for dry reforming reaction, and method for producing the same

Abstract

To provide a production method of a gas mixture capable of keeping intensity and activity of a catalyst even when a raw material gas contains moisture vapor in dry reforming reaction and thus producing a gas mixture for a long period, a catalyst for producing a gas mixture, and a production method of the catalyst for producing a gas mixture.SOLUTION: A production method of a gas mixture includes a step for heating a catalyst layer to 700°C or higher and 800°C or lower. and a step for letting a raw material gas containing carbon dioxide and methane pass through the heated catalyst layer and producing a gas mixture containing carbon monoxide and water from the raw material gas in dry reforming reaction. The catalyst layer includes a catalyst 25 for dry reforming reaction containing a composite obtained by kneading and burning a compound that provides at least one or more of γ-alumina and θ-alumina and a sintered substance of a clay compound, and a metal carried by the composite.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for producing a mixed gas, a catalyst for dry reforming reaction, and a method for producing the same.

Background Art

[0002] Currently, the reduction and fixation of carbon dioxide, which has an adverse impact on the environment as a global warming gas, is an urgent global task. In response to this, various technologies such as CO2 emission reduction technology, CO2 separation and recovery technology, CO2 useful resource conversion technology, and CO2 fixation technology are being researched and developed for practical use everywhere.

[0003] As a method for effectively using carbon dioxide, for example, a method of generating methane from carbon dioxide and hydrogen by a methanation reaction, generating carbon monoxide from methane and carbon dioxide by a dry reforming reaction, and depositing solid carbon from carbon monoxide by a Bouduard reaction is known, and the reaction is efficiently caused by using a catalyst suitable for each reaction.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In dry reforming reactions, catalyst degradation due to the precipitation of solid carbon is a problem, and various measures have been taken to address it (see Patent Documents 1 and 2). However, since not only methane but also water vapor is generated in the methanation reaction, catalyst degradation due to water vapor is also a problem. In particular, catalysts using γ-alumina as a support have low alkali resistance, and if exposed to alkaline gases containing water vapor for a long time, the hydration reaction proceeds and they are transformed into boehmite, which has a small specific surface area. This can lead to a decrease in catalyst strength and may cause degradation of the catalyst itself or a decrease in its activity.

[0006] This invention has been made in view of these circumstances, and aims to provide a method for producing a mixed gas, a catalyst for a dry reforming reaction, and a method for producing the same, which can maintain the strength and activity of the catalyst even when the raw material gas contains water vapor in a dry reforming reaction, and enable the production of the mixed gas over a long period of time. [Means for solving the problem]

[0007] (1) To achieve the above objective, the present invention provides a method for producing a mixed gas, comprising the steps of: heating a catalyst layer to 700°C or higher and 800°C or lower; passing a raw material gas containing carbon dioxide and methane through the heated catalyst layer to produce a mixed gas containing carbon monoxide and water from the raw material gas by a dry reforming reaction; wherein the catalyst layer is characterized by using a catalyst for a dry reforming reaction comprising a composite obtained by kneading and firing a sintered product of a compound that gives at least one of γ-alumina and θ-alumina and a clay compound, and a metal supported by the composite.

[0008] Thus, because the catalyst used is formed from a composite obtained by kneading and firing a sintered clay compound with γ-alumina or θ-alumina, and a metal supported by the composite, the catalyst's strength and activity can be maintained even if the raw material gas contains water vapor. As a result, mixed gases can be produced over long periods of time.

[0009] (2) Furthermore, in the method for producing a mixed gas of the present invention, the composite is characterized in that the total amount of γ-alumina and θ-alumina is 40% by mass or more and 60% by mass or less. This makes it possible to increase the specific surface area of ​​the composite and enhance the activity of the catalyst while maintaining high alkali resistance.

[0010] (3) Furthermore, in the method for producing a mixed gas of the present invention, the metal is characterized in that it is one or more combinations selected from the group consisting of nickel, rhodium, iridium, and platinum. This makes it possible to promote the dry reforming reaction.

[0011] (4) Furthermore, in the method for producing a mixed gas of the present invention, the catalyst for the dry reforming reaction is characterized in that 90% or more by mass consists of particles with a particle size range of 0.5 mm to 5 mm. This increases the specific surface area of ​​the composite and enhances the activity of the catalyst.

[0012] (5) In addition, in the method for producing a mixed gas of the present invention, the catalyst layer is the dry reforming reaction catalyst in the gas flow path at a concentration of 0.5 g / cm³. 3 More than 1.0g / cm 3 The following is a characteristic feature: the catalyst is filled in as described below. This allows the catalyst to function fully.

[0013] (6) Furthermore, the present invention provides a method for producing a catalyst for a dry reforming reaction, comprising the steps of: kneading at least one of γ-alumina and θ-alumina with a clay compound to obtain a kneaded product such that the total content of γ-alumina and θ-alumina is 40% by mass or more and 60% by mass or less; molding the kneaded product; firing the molded body obtained in the molding at 900°C or more and 1200°C or less; and pulverizing the fired body obtained in the firing and classifying it so that 90% by mass or more of the particle size range is 0.5 mm or more and 5 mm or less. This makes it possible to produce a catalyst for a dry reforming reaction that can maintain its strength and activity even if the raw material gas contains water vapor.

[0014] (7) Further, the catalyst for dry reforming reaction of the present invention comprises a composite which is a sintered product of a molded body containing at least one or more of γ-alumina and θ-alumina and a clay compound, and a metal supported by the composite, and is characterized in that 90% by mass or more has a particle size range of 0.5 mm or more and 5 mm or less. Thereby, it can be used as a catalyst for dry reforming reaction that can maintain strength and activity even when the raw material gas contains water vapor.

Effects of the Invention

[0015] According to the present invention, even when the raw material gas contains water vapor in the dry reforming reaction, the strength and activity of the catalyst can be maintained, and it becomes possible to produce a mixed gas over a long period of time.

Brief Description of the Drawings

[0016] [Figure 1] It is a schematic diagram of a solid carbon precipitation device used for the production of a mixed gas. [Figure 2] It is a schematic diagram showing an example of a gas flow path.

Modes for Carrying Out the Invention

[0017] Hereinafter, embodiments of the present invention will be described.

[0018] [Method for Producing Mixed Gas] (Principle) The method for producing a mixed gas of the present invention is applied to the second reaction (dry reforming reaction) in a series of reactions for precipitating solid carbon from a raw material gas containing carbon dioxide and hydrogen as described below. First reaction: CO2 + 4H2 → CH4 + 2H2O ΔH = -165 kJ / mol…(Equation 1) Second reaction: CO2 + CH4 → 2CO + 2H2 ΔH = 248 kJ / mol…(Equation 2) Third reaction: 2CO → C + CO2 ΔH = -172 kJ / mol…(Equation 3).

[0019] In the above reaction, as shown in Formula 1, as the first reaction, a methanation reaction that converts carbon dioxide and hydrogen into methane occurs. In the first reaction, usually, methane and water vapor are produced from 1 mol of carbon dioxide and 4 mol of hydrogen through a catalyst. The raw material gas containing carbon dioxide and hydrogen becomes a mixed gas composed of methane and water vapor synthesized in the first reaction, unreacted carbon dioxide, and hydrogen.

[0020] Next, as shown in Formula 2, as the second reaction, a dry reforming reaction that converts carbon dioxide and methane into carbon monoxide occurs. In the second reaction, 2 mol of carbon monoxide and 2 mol of hydrogen are produced from 1 mol of methane and 1 mol of carbon dioxide synthesized in the first reaction through a catalyst. The raw material gas after the second reaction becomes a mixed gas containing hydrogen, methane, carbon dioxide, carbon monoxide, and water vapor.

[0021] Then, as shown in Formula 3, as the third reaction, solid carbon is deposited from carbon monoxide by the Boudouard reaction. In the third reaction, 1 mol of solid carbon and 1 mol of carbon dioxide are produced from 2 mol of carbon monoxide through a catalyst. Since solid carbon is deposited on the surface of the catalyst, the catalyst is recovered together to recover the deposited solid carbon. In addition, various reaction systems compete in the third reaction. Therefore, the raw material gas after the third reaction becomes a mixed gas containing hydrogen, methane, carbon dioxide, carbon monoxide, and water vapor.

[0022] (Device Configuration) FIG. 1 is a schematic diagram of a solid carbon deposition device 1 used for producing a mixed gas. A series of reactions as described above can be carried out in a solid carbon deposition device 1 that deposits solid carbon from process exhaust gas containing carbon dioxide. In particular, the part related to the method for producing the mixed gas of the present invention is shown in region A1 surrounded by a dashed line.

[0023] Note that the process exhaust gas refers to exhaust gas containing carbon dioxide discharged from, for example, a cement clinker firing process, a quicklime production process, a thermal power plant, a waste incineration treatment facility, a firing facility for ceramics, etc., a steel mill, and a chemical plant.

[0024] The solid carbon deposition apparatus 1 has a first reactor 10, a second reactor 20, and a third reactor 30 connected in series. The solid carbon deposition apparatus 1 may also be equipped with a hydrogen supply system, a hydrogen flow meter, a gas mixer, a gas separator, and a water vapor removal system.

[0025] The first reactor 10 brings the supplied raw material gas into contact with a catalyst that activates the methanation reaction, producing methane and water from the raw material gas as shown in Equation 1. The first reactor 10 is equipped with a gas flow reaction tube 13 and a methanation reaction catalyst 15. The gas flow reaction tube 13 is filled with the methanation reaction catalyst 15. The gas flow reaction tube 13 can be heated to 300-550°C by a heating furnace. For example, the first reactor 10 is an atmospheric pressure flow reactor with a fixed gas flow tube.

[0026] The catalyst for activating the methanation reaction can be any material capable of producing methane from carbon dioxide and hydrogen, such as Ni, Ru, Pt, and Rh. Various oxides and aluminosilicates such as CeO2, ZrO2, Y2O3, and Al2O3 can be used as the support. A helical shape is preferred because it requires less catalyst volume. When a helical catalyst is used for the methanation reaction, it is prepared by forming a metal plate, such as aluminum, into a spiral shape and then applying a paste-like catalyst to it.

[0027] The second reactor 20 converts methane to carbon monoxide as shown in Equation 2 by heating a mixed gas containing methane supplied from the first reactor 10 in contact with a catalyst that promotes the dry reforming reaction. Preferably, the mixed gas supplied to the second reactor 20 is supplied so that the space velocity is 1300 to 5400 / h. The second reactor 20 is equipped with a gas flow reaction tube 23 and a catalyst 25 for the dry reforming reaction. The gas flow reaction tube 23 is filled with the catalyst 25 for the dry reforming reaction. The gas flow reaction tube 23 can be heated to 700 to 900°C by a heating furnace. Since there is little concern that the gas flow path in the reactor will be blocked by solid products, for example, an atmospheric pressure flow reactor with a fixed gas flow side tube is used in the second reactor 20.

[0028] The catalyst for activating the dry reforming reaction can be one or more combinations selected from the group consisting of nickel, rhodium, iridium, and platinum, capable of producing carbon monoxide and hydrogen from carbon dioxide and methane. Nickel and rhodium are preferred, for example. As a support, a composite obtained by kneading and firing a sintered product of a compound that gives at least one of γ-alumina and θ-alumina and a clay compound can be used. Details of the dry reforming reaction catalyst 25 formed therefrom will be described later.

[0029] The third reactor 30 brings a mixed gas containing carbon monoxide supplied from the second reactor 20 into contact with a catalyst that activates the Boudoir reaction, and precipitates solid carbon from carbon monoxide as shown in Equation 3. The third reactor 30 is equipped with a gas flow reaction tube 33 and a Boudoir reaction catalyst 35. The gas flow reaction tube 33 is filled with the Boudoir reaction catalyst 35. The gas flow reaction tube 33 can be heated to 400-500°C by a heating furnace.

[0030] The catalyst for activating the Boudoir reaction can be any catalyst capable of precipitating solid carbon from carbon monoxide, such as Ni and Fe. Various oxides and aluminosilicates such as CeO2, ZrO2, Y2O3, and Al2O3 can be used as the support. It is preferable to form the catalyst in a helical shape.

[0031] Gas mixer M1 adjusts the mixed gas supplied to the second reactor 20, and gas mixer M2 adjusts the mixed gas supplied to the third reactor 30. Gas mixers M1 and M2 remove some of the mixed gas discharged from each reactor and add other gases to adjust the gas to a composition ratio suitable for the next reaction.

[0032] (Charging of catalyst for dry reforming reaction) The packing of the dry reforming reaction catalyst 25 will now be described. Figure 2 is a schematic diagram showing an example of a gas flow path used in the production of a mixed gas. The flow path formed on the inner wall surface 23a of the gas flow reaction tube is packed with the dry reforming reaction catalyst 25 and quartz wool 27. It is preferable to fix the dry reforming reaction catalyst 25 by packing the quartz wool 27 at both ends of the flow path.

[0033] (Process flow) Next, we will explain the method for precipitating solid carbon through a series of reactions. First, the raw material gas is supplied to the first reactor 10, and the raw material gas is circulated through the gas flow reaction tube of the first reactor 10. At this time, the raw material gas ratio is adjusted so that H2 / CO2 = 4 or less. The gas flow reaction tube is filled with a catalyst heated to 300-550°C by a heating furnace, and the catalyst, which activates the methanation reaction, comes into contact with the raw material gas, generating methane from the raw material gas.

[0034] Next, the mixed gas discharged from the first reactor 10 is supplied to the second reactor 20, and the mixed gas is circulated through the gas flow reaction tube of the second reactor 20. The catalyst for the dry reforming reaction inside the gas flow reaction tube is heated to between 700°C and 900°C by a heating furnace, and the catalyst comes into contact with the mixed gas, converting methane into carbon monoxide.

[0035] Next, the mixed gas discharged from the second reactor 20 is supplied to the third reactor 30, and the mixed gas is circulated through the gas flow reaction tube of the third reactor 30. The gas flow reaction tube is filled with a catalyst heated to approximately 450°C by a heating furnace. The catalyst, which activates the Boudoir reaction, comes into contact with the mixed gas, and carbon monoxide is converted into solid carbon, which precipitates on the surface of the catalyst. Solid carbon can be recovered by recovering the catalyst on which the solid carbon has precipitated.

[0036] [Composition of catalyst for dry reforming reaction] The dry reforming catalyst 25 comprises a composite and a metal supported by the composite. The composite includes a sintered product obtained by calcining a mixture of at least one of γ-alumina and θ-alumina and a clay compound.

[0037] If the alumina content of the composite is too low, its specific surface area cannot be sufficiently increased. On the other hand, if the alumina content is too high, alkali resistance decreases. For these reasons, the alumina content of the composite is preferably 40% to 60% by mass.

[0038] Sintered clay compounds are obtained by sintering clay compounds. Examples of clay compounds include aluminosilicates such as kaolinite, mullite, and illite, as well as pottery clays such as Kaorime clay, Kasaoka clay, Kibushi clay, and Shigaraki clay, which contain a large amount of aluminosilicate. These can be used individually or in combination of two or more. Furthermore, Kaorime clay is preferred because it provides high processing capacity. Sintered clay compounds are obtained by firing these clay compounds at a temperature of 900°C to 1200°C. Sintered clay compounds are effective in promoting the sintering of γ-alumina and θ-alumina.

[0039] The content of sintered clay compounds in the composite can be adjusted as appropriate depending on the amount of alumina. For example, if the alumina content in the composite is 40% to 60% by mass, the content of sintered clay compounds (the total amount including silica, if silica is included) can be adjusted to 60% to 40% by mass. Note that the content of sintered clay compounds here refers to the mass of the clay compound after drying at 105°C during manufacturing.

[0040] The composite supports a metal as an active ingredient. The supported metals include one or more combinations selected from the group consisting of nickel, rhodium, iridium, and platinum. The amount of metal supported is 0.01% to 25% by mass, preferably 1% to 15% by mass, and more preferably 5% to 15% by mass, of the weight of the support, taking into account the processing performance and cost of the dry reforming reaction.

[0041] [Method for producing catalysts for dry reforming reactions] The catalyst 25 for the dry reforming reaction is produced by a manufacturing method that includes the steps of kneading a compound that gives at least one of γ-alumina and θ-alumina with a clay compound to obtain a kneaded product, and after shaping the kneaded product, firing the molded body at a temperature of 900°C to 1200°C.

[0042] "A compound that provides γ-alumina" refers to γ-alumina or a compound that produces γ-alumina by calcination. Compounds that produce γ-alumina by calcination are not particularly limited, but include hydroxides such as gibbsite, diaspore, and boehmite, nitrates such as aluminum nitrate, and chlorides such as aluminum chloride. Compounds that provide γ-alumina can be used individually or in combination of two or more. Furthermore, "a compound that provides θ-alumina" refers to θ-alumina or a compound that produces θ-alumina by calcination. Compounds that produce θ-alumina by calcination are not particularly limited, but include aluminum hydroxide.

[0043] When obtaining a compound by kneading the above raw materials, solvents such as water and 1,3-butanediol may be added to the compound to ensure kneadability and subsequent moldability. The kneading method can be carried out using a commonly used kneader or the like.

[0044] Regarding the blending ratio of raw materials, it is preferable to set the total content of the compounds that provide γ-alumina and θ-alumina in the solid content of the kneaded product to 40% to 60% by mass in order to achieve a total content of γ-alumina and θ-alumina in the complex of 40% to 60% by mass.

[0045] The particle size of γ-alumina and θ-alumina is preferably such that the average particle size (D50) is 50 μm or less, and more preferably 10 to 30 μm, in order to maintain the specific surface area while reducing the loss of alumina due to sintering.

[0046] On the other hand, the content of the clay compound in the solid content of the kneaded product can be 40% to 60% by mass, depending on the γ-alumina content, after drying at 105°C. Furthermore, in order to maintain alkali resistance while maintaining performance, the average particle size (D50) of the clay compound is preferably 100 μm or less, and more preferably 10 to 50 μm.

[0047] The molding method for the compound can be selected according to the shape of the material to be produced. For example, when molding the compound into a spherical molded body, a granulator or the like can be used. When molding the compound into cylindrical, rectangular, tubular, honeycomb-shaped molded bodies, an extrusion molding machine or the like can be used. After molding the compound, the molded body may be fired immediately, but drying may be performed before firing as needed to prevent the occurrence of cracks, etc. Furthermore, since the raw material contains clay compounds, it has excellent moldability. Therefore, it can be easily molded even without adding a binder.

[0048] The molded body is fired at a temperature of 900°C to 1200°C. By firing within this temperature range, it is possible to obtain a catalyst for dry reforming reactions that maintains the specific surface area of ​​γ-alumina and θ-alumina while increasing its strength.

[0049] If the firing temperature is below 900°C, the strength of the dry reforming catalyst decreases, and it becomes prone to deformation. On the other hand, if the firing temperature exceeds 1200°C, γ-alumina and θ-alumina undergo a phase transition to α-alumina with a corundum structure, and sintering of the alumina progresses, reducing the specific surface area of ​​the dry reforming catalyst. The firing method is not particularly limited and can be carried out using known firing apparatus. Examples of firing apparatus include batch furnaces, tunnel kilns, rotary kilns, etc.

[0050] The composite obtained in this way is crushed and classified. Crushing methods include jaw crushers and ball mills. The crushed material is then classified so that 90% or more by mass has a particle size range of 0.5 mm to 5 mm.

[0051] Next, a metal is supported on the composite obtained in this way. The method of supporting the metal is not limited, but one example is impregnation with a metal aqueous solution. In the method of impregnation with a metal aqueous solution, the composite is first impregnated with a metal ion-containing aqueous solution. After impregnation, the water adhering to the composite is removed using an evaporator, centrifuge (low-speed rotation), etc., and the metal can be supported on the composite by calcination. For example, when supporting ruthenium, the composite is impregnated with a hexaammineruthenium chloride solution, the water is removed, and it is calcined at about 300-500°C for 2 hours.

[0052] Furthermore, removing excess moisture from the material surface by air drying before firing, such as by applying hot air or placing it in a dryer, is also effective. In particular, when firing composites without gradually increasing the firing temperature, pre-firing with air drying allows for firing with high thermal efficiency.

[0053] Furthermore, the removed metal ion-containing aqueous solution can be recovered and reused. The calcined body may also be subjected to hydrogen reduction after calcination. Hydrogen reduction can be performed, for example, by passing a 10% hydrogen-containing gas at 500°C through the calcined body. Hydrogen reduction improves the activity of catalysts, especially those whose catalytic activity has decreased.

[0054] [Examples] (1. Preparation of carrier samples) Clay for 40-60% by mass of γ-alumina, respectively. compound After adding 60-40% by mass (see Table 1), the mixture was crushed and mixed, then water was added and it was molded into a cylindrical shape. After molding, it was dried at 150°C for 12 hours and then calcined at 1000°C for 10 hours to obtain a composite support. On the other hand, as the γ-alumina support, the raw material of γ-alumina was used as is.

[0055] (2. Performance evaluation of carrier samples) As a performance evaluation, the specific surface area of ​​each support sample was measured. 2 g of each support sample was immersed in 20 g of 28% ammonia water and maintained at a temperature of 150-230°C for 12 hours in a 100 ml autoclave. After heating, the specific surface area decreased significantly in the case of the γ-alumina support catalyst, but in the case of the composite support, the fluctuation was small and the performance was maintained. Table 1 shows the composition and specific surface area of ​​the γ-alumina support and the composite support, respectively.

[0056] [Table 1]

[0057] (3. Preparation and preparation of catalyst samples) The catalyst samples were prepared according to the following procedure. First, each carrier sample was pulverized to a particle size range of 5 mm to 0.5 mm. 60 g of the sized carrier sample, 40 g of water, and 30 g of nickel nitrate hexahydrate (of which 6 g was Ni) were mixed and impregnated into the carrier sample by capillary action. After impregnation, the water was evaporated at 105°C for 12 hours to dry the sample. The sample was calcined at 500°C for 2 hours under an atmospheric environment to remove nitrate. The catalyst sample was prepared by reduction treatment at 700°C for 1 hour in a hydrogen atmosphere (200 ml / min).

[0058] Each catalyst sample was packed into a 8mm diameter quartz tube at a dose of 3.027g. Quartz wool was packed 7.7cm apart before and after the catalyst sample in the flow path. The packing density for all catalyst samples was 0.782g / cm². 3 It was filled in such a way.

[0059] (4. Performance evaluation of catalysts for dry reforming reactions) After performing a methanation reaction under the same conditions, a dry reforming reaction was carried out using each catalyst sample obtained above, and the reaction performance was evaluated. For the methanation reaction, Ni was supported on a CeO2 support, and the gas flow reaction tube was heated to 450°C. For the dry reforming reaction, an alumina support or composite was used as the catalyst support, and the gas flow reaction tube was heated to 800°C.

[0060] Table 2 shows the reaction conditions for methanation and dry reforming catalysts. Table 3 shows the composition of the outlet gas from the second reactor. As shown in Table 3, the performance of the catalyst for the dry reforming reaction was equivalent to that of the conventional γ-alumina support catalyst.

[0061] [Table 2]

[0062] [Table 3] [Explanation of symbols]

[0063] 1. Solid carbon deposition apparatus 10 First Reactor 13 Gas flow reaction tube 15 Catalysts for methanation reactions 20 Second Reactor 23 Gas flow reaction tube 23a Inner wall surface 25 Catalysts for dry reforming reactions 27 Quartz wool 30 Third Reactor 33 Gas flow reaction tube 35 Catalyst for Boudoir reaction A1 area M1, M2 gas mixer

Claims

1. A step of heating the catalyst layer to 700°C or higher and 800°C or lower, The process includes passing a raw material gas containing carbon dioxide and methane through the heated catalyst layer to generate a mixed gas containing carbon monoxide and water from the raw material gas by a dry reforming reaction, A method for producing a mixed gas, characterized in that the catalyst layer is made by kneading and calcining a clay compound containing a γ-alumina compound and an aluminosilicate, impregnating the composite obtained by this process with a nickel-containing metal aqueous solution, and then calcining the composite so that the nickel-containing metal is supported on the composite, thereby using a catalyst for a dry reforming reaction.

2. The method for producing a mixed gas according to claim 1, characterized in that the composite contains 40% by mass or more and 60% by mass or less of the γ-alumina.

3. The method for producing a mixed gas according to claim 1 or 2, characterized in that the catalyst for the dry reforming reaction is composed of particles with a particle size range of 0.5 mm to 5 mm, comprising 90% by mass or more.

4. As the catalyst layer, the catalyst for the dry reforming reaction is supplied to the gas flow path at a rate of 0.5 g / cm³. ３ 1.0g / cm or more ３ A method for producing a mixed gas according to any one of claims 1 to 3, characterized by filling as follows.

5. A step of kneading a clay compound containing γ-alumina and an aluminosilicate such that the amount of γ-alumina is 40% by mass or more and 60% by mass or less to obtain a kneaded product, The process of forming the aforementioned kneaded product, A step of firing the molded body obtained by the above molding at a temperature of 900°C to 1200°C, The calcined body obtained by the calcination process is crushed and classified so that 90% or more by mass has a particle size range of 0.5 mm or more and 5 mm or less. A method for producing a catalyst for a dry reforming reaction, comprising the steps of: impregnating the calcined body obtained in the classification with an aqueous metal aqueous solution containing nickel; and then calcining the calcined body to support the nickel-containing metal on the calcined body.

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