Reactor

Abstract

To provide a novel technology that reduces the temperature bias of the catalyst part producing hydrocarbon by the reaction according to the FT method.SOLUTION: A reaction device 10 includes a reactor 12 configured to discharge hydrocarbon generated from a raw material gas introduced from the upstream side inlet 12a from the downstream side outlet 12b, a first catalyst part 14 arranged in the inside of the reactor 12 and producing carbon monoxide using hydrogen and carbon dioxide contained in the raw material gas, and a second catalyst part 16 arranged in the inside of the reactor 12 and producing hydrocarbon using carbon monoxide and hydrogen produced in the first catalyst part 14. The reaction device 10 is configured so as the difference between the gas temperature before the carbon monoxide-containing gas flows into the second catalyst part 16 and the temperature in the high temperature region where the second catalyst part 16 has the highest temperature when producing hydrocarbon to be 30°C or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to catalyst technology used in producing hydrocarbons. [Background technology]

[0002] As a method for effectively utilizing carbon dioxide contained in exhaust gases, etc., studies have been conducted on producing liquid hydrocarbons with high energy density from carbon dioxide and hydrogen in the presence of a catalyst (for example, Patent Document 1). Also, the Fischer-Tropsch process (hereinafter referred to as the "FT process" as appropriate) is known as a method for producing hydrocarbons using hydrogen and carbon monoxide (see Non-Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 7-80309 [Non-patent literature]

[0004] [Non-Patent Document 1] Energy & Fuels, Vol. 23, 4195(2009) Summary of the Invention [Problem to be solved by the invention]

[0005] The catalysts used in the FT process mainly contain metals such as cobalt, ruthenium, and iron. Furthermore, the catalytic reaction in the FT process is exothermic, and heat tends to be generated more upstream in the catalyst layer. Therefore, some kind of ingenuity is required to ensure a uniform reaction temperature throughout the entire FT catalyst layer.

[0006] The present invention has been made in view of the above circumstances, and one of its exemplary purposes is to provide a new technology for reducing the temperature bias in a catalyst portion that produces hydrocarbons through a reaction by the FT method. [Means for solving the problem]

[0007] To solve the above problems, a reaction apparatus according to one embodiment of the present invention comprises a reactor configured to discharge hydrocarbons produced from a feed gas introduced through an upstream inlet from a downstream outlet, a first catalytic section disposed inside the reactor for producing carbon monoxide using hydrogen and carbon dioxide contained in the feed gas, and a second catalytic section disposed inside the reactor for producing hydrocarbons using the carbon monoxide and hydrogen produced in the first catalytic section. The reaction apparatus is configured so that the difference between the temperature of the carbon monoxide-containing gas before it flows into the second catalytic section and the temperature of the high-temperature region in the second catalytic section that becomes the highest during hydrocarbon production is 30°C or less. [Effects of the Invention]

[0008] According to one aspect of the present invention, it is possible to reduce the temperature deviation of the catalyst portion that generates hydrocarbons. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram showing a schematic configuration of a reaction apparatus according to a first embodiment. [Figure 2] FIG. 10 is a schematic diagram showing a schematic configuration of a reaction apparatus according to a second embodiment. [Figure 3] FIG. 10 is a schematic diagram showing a schematic configuration of a reaction apparatus according to a third embodiment. [Figure 4] FIG. 10 is a schematic diagram showing a schematic configuration of a reaction apparatus according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] First, embodiments of the present invention will be listed. A reaction apparatus according to one embodiment of the present invention comprises a reactor configured to discharge hydrocarbons produced from a feed gas introduced through an upstream inlet from a downstream outlet, a first catalytic section disposed inside the reactor to produce carbon monoxide using hydrogen and carbon dioxide contained in the feed gas, and a second catalytic section disposed inside the reactor to produce hydrocarbons using the carbon monoxide and hydrogen produced in the first catalytic section. The reactor is configured so that the difference between the gas temperature before the carbon monoxide-containing gas flows into the second catalytic section and the temperature of the high-temperature region in the second catalytic section that becomes the hottest during hydrocarbon production is 30°C or less.

[0011] Heat tends to concentrate in the end region of the second catalyst section on the side where carbon monoxide flows in. This results in a large temperature imbalance in the second catalyst section. According to this embodiment, the temperature rise in the high-temperature region, which becomes the hottest in the second catalyst section when hydrocarbons are generated, is kept to 30°C or less compared to the gas temperature before the carbon monoxide-containing gas flows into the second catalyst section, thereby reducing the temperature imbalance in the second catalyst section. As a result, a stable catalytic reaction can be achieved in the second catalyst section.

[0012] The first catalyst portion may contain at least one of copper and copper oxide, and may also contain a catalyst that produces carbon monoxide from hydrogen and carbon dioxide by a so-called reverse shift reaction.

[0013] The second catalyst portion may include a support containing at least one of iron and iron oxide, and an additive metal, which is at least one metal selected from the group consisting of alkali metals and alkaline earth metals, added to the support. The support may be, for example, one or more substances selected from iron (Fe), ferric oxide (Fe2O3), triiron tetroxide (Fe3O4), etc.

[0014] The second catalyst section may have a carbon monoxide conversion rate [mol / s] in the upstream half of the region that is 30 to 60% of the carbon monoxide conversion rate [mol / s] in the downstream half of the region, which suppresses the reaction in the upstream side, where heat generation tends to concentrate, compared to the downstream side, thereby reducing temperature imbalance in the second catalyst section.

[0015] The second catalyst section may contain 10 to 50 mass% of inert catalyst in the upstream half of the second catalyst section. This suppresses reactions on the upstream side where heat generation tends to concentrate in the second catalyst section. It is also preferable that the amount of inert catalyst in the upstream half of the second catalyst section is greater than the amount of inert catalyst in the downstream half of the second catalyst section.

[0016] The second catalyst section may have 10 to 50 mass % of the catalyst contained in the first catalyst section mixed in its upstream half region. Because the reaction in the first catalyst section is an endothermic reaction, this suppresses the reaction on the upstream side where heat generation tends to concentrate in the second catalyst section.

[0017] The amount of added metal in the upstream half of the second catalyst section may be less than 10% by mass, and the amount of added metal in the downstream half may be 10% by mass or more. A low proportion of added metal typically results in low activity and suppressed reaction. This suppresses the reaction on the upstream side, where heat generation tends to concentrate, compared to the downstream side, thereby reducing temperature imbalances in the second catalyst section.

[0018] The first catalyst section and the second catalyst section may be spaced apart, which makes it easier for gas coming out of the first catalyst section to flow uniformly into the second catalyst section.

[0019] A flow straightening section may be provided between the first catalyst section and the second catalyst section to straighten the flow of carbon monoxide from the first catalyst section to the second catalyst section, making it easier for the gas leaving the first catalyst section to flow uniformly into the second catalyst section.

[0020] A return flow path may be provided between the first catalyst section and the second catalyst section, with the first catalyst section being located upstream of the return flow path and on the outer periphery of the reactor, and the second catalyst section being located downstream of the return flow path and inside the first catalyst section. This allows heat generation in the second catalyst section to be utilized for heat absorption in the first catalyst section. Furthermore, a heat transfer path or heat exchanger is not required between the first catalyst section and the second catalyst section.

[0021] Any combination of the above components and any transformation of the present invention into a method, device, system, etc. are also valid aspects of the present invention. Appropriate combinations of the above elements may also be included in the scope of the invention for which patent protection is sought by this patent application.

[0022] The present invention will be described below with reference to the drawings based on preferred embodiments. The embodiments are illustrative and do not limit the invention, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention. The same or equivalent components, parts, and processes shown in the drawings are designated by the same reference numerals, and redundant descriptions will be omitted where appropriate. The scale and shape of each part shown in the drawings are set for convenience to facilitate explanation and should not be interpreted as limiting unless otherwise specified. The same components may have slightly different scales between the drawings. Furthermore, when terms such as "first" and "second" are used in this specification or claims, unless otherwise specified, they do not represent any order or importance, but are used to distinguish one configuration from another.

[0023] [First embodiment] The schematic configuration of a reaction apparatus according to a first embodiment will be described. Fig. 1 is a schematic diagram showing the schematic configuration of a reaction apparatus according to the first embodiment. The reaction apparatus 10 shown in Fig. 1 includes a reactor 12 configured to discharge hydrocarbons generated from a feed gas introduced through an upstream inlet 12a from a downstream outlet 12b, a first catalyst section 14 disposed inside the reactor 12 and generating carbon monoxide using hydrogen and carbon dioxide contained in the feed gas, and a second catalyst section 16 disposed inside the reactor 12 and generating hydrocarbons using the carbon monoxide generated in the first catalyst section 14 and hydrogen contained in the feed gas.

[0024] The first catalyst section 14 is filled with a pellet-shaped reverse shift catalyst 14a that causes a reverse shift reaction. In the reverse shift catalyst 14a, carbon monoxide is produced from hydrogen and carbon dioxide through the reverse shift reaction. The second catalyst section 16 is filled with a pellet-shaped FT catalyst 16a that causes a reaction by the FT method. In the FT catalyst 16a, hydrocarbons are produced from carbon monoxide and hydrogen through a reaction by the FT method. This catalyst system can easily produce gaseous or liquid hydrocarbons by introducing a raw material gas containing carbon dioxide, hydrogen, and carbon monoxide into the inlet side of the reactor 12.

[0025] The reactor 10 produces CH4 and C2-C4 components, which are gaseous hydrocarbons with 1 to 4 carbon atoms, such as methane, ethane, propane, and butane, and C5+ components, which are hydrocarbons with 5 or more carbon atoms and are liquid oil components at normal pressure (for example, linear alkanes with a carbon number n of 5 or more), and performs gas-liquid separation of the gas components and oil components, and in some cases, fractional distillation to extract the desired components.

[0026] Because the reaction by the FT method is an exothermic reaction, heat is likely to be concentrated in the end region R of the second catalyst section 16, on the side where carbon monoxide flows in, of the FT catalyst 16a packed in the second catalyst section 16. As a result, the temperature in the end region R of the second catalyst section 16 is likely to rise, and if left as is, the temperature will become uneven across the entire second catalyst section 16. Therefore, the reaction device 10 according to the first embodiment is configured so that the difference between the gas temperature before the carbon monoxide-containing gas flows into the second catalyst section 16 and the temperature of the high-temperature region that becomes the hottest in the second catalyst section 16 when hydrocarbons are produced is 30°C or less.

[0027] This reduces temperature bias in the second catalyst section 16 by limiting the temperature rise in the high-temperature region (e.g., end region R) that becomes the hottest in the second catalyst section 16 when hydrocarbons are produced to 30°C or less compared to the gas temperature immediately before the carbon monoxide-containing gas flows into the second catalyst section 16. As a result, a stable catalytic reaction in the second catalyst section 16 is achieved.

[0028] In the reactor 10 according to this embodiment, in order to suppress a local temperature rise in the end region R, 10 to 50 mass % (based on the total amount of catalyst packed in this region; the same applies below) of inert catalyst 18 is mixed into the upstream half (or one-third, or less) region of the second catalyst section 16. The inert catalyst 18 is, for example, alumina balls. The amount of inert catalyst 18 may be 15 mass % or more, or may be 20 mass % or more. Alternatively, the amount of inert catalyst 18 may be 40 mass % or less, or may be 30 mass % or less. In this specification, "half (or one-third, or less) region" refers to the entire volume of the second catalyst section 16.

[0029] This suppresses the reaction on the upstream side (end region R) where heat generation tends to concentrate in the second catalyst section 16, preventing sudden heat generation on the upstream side. Furthermore, it is preferable that the amount of inert catalyst in the upstream half (or one-third or less) of the second catalyst section 16 is greater than the amount of inert catalyst in the downstream half (or one-third or less) of the second catalyst section 16. This reduces the temperature difference between the upstream and downstream sides of the inert catalyst 18.

[0030] [Second embodiment] FIG. 2 is a schematic diagram showing the overall configuration of a reactor according to the second embodiment. Components similar to those in the reactor 10 according to the first embodiment are denoted by the same reference numerals, and descriptions thereof will be omitted where appropriate. In the reactor 20 according to the second embodiment, a reverse shift catalyst 14a is mixed in addition to the FT catalyst 16a in the upstream half of the second catalyst section 16 in order to suppress heat generation on the upstream side of the second catalyst section 16. In other words, a portion of the first catalyst section 14 and a portion of the second catalyst section 16 overlap (overlap region R'). The second catalyst section 16 is mixed with 10 to 50 mass% of the reverse shift catalyst 14a in the upstream half of the second catalyst section 16, including the overlap region R'. This suppresses reactions on the upstream side, where heat generation tends to concentrate in the second catalyst section 16.

[0031] In this way, multiple catalysts with different reaction characteristics may be used to suppress heat generation at the upstream end of the second catalyst section 16. For example, the FT catalyst 16a according to each embodiment may have a first FT catalyst used in a reaction by the FT method and a second FT catalyst used in a reaction by the FT method and having different reaction characteristics in the FT method from the first FT catalyst. Also, instead of or in addition to the second FT catalyst, a non-FT catalyst that does not involve a reaction by the FT method may be used. Naturally, the non-FT catalyst has different reaction characteristics from the first FT catalyst and the second FT catalyst.

[0032] Here, different reaction characteristics refer to cases where the activity differs due to differences in the elements or composition that make up the catalyst, or differences in shape (form). It can also be said that reaction characteristics differ when the dominant reaction during the FT method reaction due to the action of the catalyst differs. In the first and second embodiments, by having the second catalyst section 16 contain multiple types of catalysts that generate different amounts of heat during the catalytic reaction, it is possible to suppress localized heat generation in the second catalyst section 16 (particularly at the upstream end).

[0033] As described above, the reaction device according to each embodiment includes at least the reverse shift catalyst 14a and the FT catalyst 16a. The reverse shift catalyst 14a is a copper-based catalyst containing copper or copper oxide. This allows efficient production of carbon monoxide from carbon dioxide contained in the raw material gas. Furthermore, in the reverse shift catalyst 14a according to each embodiment, the reaction caused by the action of the copper-based catalyst is an endothermic reaction, and the reverse shift catalyst 14a can be used as a heat-absorbing portion of the FT catalyst 16a. The reverse shift catalyst 14a may also be a platinum-based catalyst containing platinum.

[0034] The FT catalyst 16a according to each embodiment may be an iron-based catalyst containing iron or iron oxide, or a cobalt-based catalyst containing cobalt. The iron-based catalyst includes a support containing at least one of iron and iron oxide, and an additive metal, which is at least one metal selected from the group consisting of alkali metals and alkaline earth metals, and is added to the support. The support may be, for example, one or more substances selected from iron (Fe), ferric oxide (Fe2O3), triiron tetroxide (Fe3O4), etc. The additive metal may be sodium or potassium.

[0035] In this way, by configuring the FT catalyst 16a of the second catalyst section 16 from multiple FT catalysts with different reaction characteristics, it is possible to suppress variations in temperature distribution within the second catalyst section 16 and efficiently produce the desired hydrocarbons. For example, the upstream side of the second catalyst section 16 (the first catalyst section 14 side) may contain a higher proportion of FT catalyst that has relatively low activity and therefore suppresses heat generation, and the downstream side may contain a higher proportion of FT catalyst that has relatively high activity and therefore promotes reaction by the FT method.

[0036] The difference in activity can also be adjusted by the amount of additive metal added to the support of the iron-based catalyst body. For example, the amount of additive metal in the upstream half of the second catalyst section 16 may be less than the amount of additive metal in the downstream half. In this case, the amount of additive metal in the upstream half may be 0.5% by mass to 20% by mass, and the amount of additive metal in the downstream half may be 1% by mass to 30% by mass. This suppresses the reaction on the upstream side, where heat generation tends to concentrate, compared to the downstream side, thereby reducing temperature imbalance in the second catalyst section 16. Furthermore, the difference in activity can also be generated by differentiating the type of additive metal added to the support on the upstream and downstream sides of the second catalyst section 16.

[0037] The second catalyst section 16 may also be configured so that the carbon monoxide conversion rate [mol / s] in the upstream half of the second catalyst section 16 is 30 to 60% of the carbon monoxide conversion rate [mol / s] in the downstream half of the second catalyst section 16. Here, the carbon monoxide conversion rate refers to the rate at which carbon monoxide is converted and reduced by the FT reaction. To achieve this configuration, multiple catalysts with different activity and reaction characteristics can be used, as described above. This suppresses the reaction upstream, where heat generation tends to concentrate, compared to the downstream side, thereby reducing temperature bias in the second catalyst section 16.

[0038] [Third embodiment] Fig. 3 is a schematic diagram showing the outline of the reactor according to the third embodiment. Note that the same components as those in the reactor 10 according to the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted as appropriate. In the reactor 30 according to the third embodiment shown in Fig. 3, the first catalyst section 14 and the second catalyst section 16 are separated from each other, and a space S is provided between the catalyst sections. The distance between the first catalyst section 14 and the second catalyst section 16 is 0.1 mm / mm per unit cross-sectional area of ​​the reactor. 2 ~0.5mm / mm 2This makes it easier for the reaction gas (carbon monoxide) G emitted from the first catalyst section 14 to flow uniformly into the second catalyst section 16. One of the reasons for the sudden exothermic reaction occurring upstream of the second catalyst section 16 is thought to be that the reaction gas generated by the reverse shift reaction in the first catalyst section 14 flows unevenly into the second catalyst section 16. Therefore, by providing a space S between the first catalyst section 14 and the second catalyst section 16, it is possible to prevent the reaction gas from flowing unevenly into the second catalyst section 16.

[0039] Furthermore, a flow straightening section may be provided between the first catalyst section 14 and the second catalyst section 16 to straighten the flow of the reaction gas G from the first catalyst section 14 to the second catalyst section 16. The flow straightening section may be, for example, a punched metal with regular holes or a flow straightening plate. By providing the flow straightening section, the reaction gas G leaving the first catalyst section 14 is more likely to flow uniformly into the second catalyst section 16.

[0040] [Fourth embodiment] Fig. 4 is a schematic diagram showing the outline configuration of a reaction apparatus according to the fourth embodiment. Components similar to those of the reaction apparatus 10 according to the first embodiment are denoted by the same reference numerals, and descriptions thereof will be omitted where appropriate. The reaction apparatus 40 shown in Fig. 4 has a cylindrical reactor 42. The reactor 42 has an outer cylinder 44 having an upstream inlet 42a on its bottom surface, and an inner cylinder 46 arranged inside the outer cylinder 44 and having a downstream outlet 42b on its bottom surface.

[0041] The annular gap between the outer cylinder 44 and the inner cylinder 46 is filled with a first catalyst section 14 in an annular shape. The inner cylinder 46 is filled with a second catalyst section 16 in a cylindrical shape. A return flow path 48 is provided in the path from the first catalyst section 14 to the second catalyst section 16. The first catalyst section 14 is located upstream of the return flow path 48 and on the outer periphery of the reactor 42, and the second catalyst section 16 is located downstream of the return flow path 48 and inside the first catalyst section 14. This allows heat generated in the second catalyst section 16 to be used to heat the first catalyst section 14, improving the heat utilization efficiency of the entire reactor. Furthermore, no heat transfer path or heat exchanger is required between the first catalyst section 14 and the second catalyst section 16.

[0042] In each of the above-described embodiments, the form of each catalyst body is not particularly limited, and may be, for example, a powder or a granular compact consisting of an aggregate of powder. The shape of the granular catalyst body is not particularly limited, and may be, for example, cylindrical, prismatic, spherical, or irregular. The particle size (maximum width) of the granular compact may be 1 mm or more and 50 mm or less. The particle size (maximum width) of the catalyst body powder may be 1 μm or more and less than 1000 μm.

[0043] The reverse shift catalyst 14a may contain metallic copper, copper oxide (CuO), or both. While the copper-based catalyst body functions as a catalyst, it contains at least metallic copper. Therefore, the catalyst is subjected to a reduction treatment before being used in a reaction. Before the reduction treatment, the copper-based catalyst body often contains copper oxide.

[0044] The content of the copper component in the copper-based catalyst body is preferably 20 to 100 mass % based on the mass of the entire copper-based catalyst body when the amount of all copper components contained in the copper-based catalyst body is converted into the amount of metallic copper.

[0045] The copper-based catalyst body may further contain zinc oxide (ZnO). When the copper-based catalyst body contains zinc oxide, liquid hydrocarbons can be produced more efficiently. When the amount of copper element contained in the copper-based catalyst body is converted into the amount of copper oxide, the proportion of the amount of zinc oxide is preferably 10 to 70 mass %, and more preferably 20 to 50 mass %, based on the total amount of copper oxide and zinc oxide.

[0046] The copper-based catalyst body may further contain a carrier that supports a copper component. When the copper-based catalyst body contains zinc oxide, the zinc oxide is usually also supported on a carrier. The carrier is preferably alumina, such as γ-alumina. The content of the carrier in the copper-based catalyst body is, for example, 0.5 to 60 mass%, preferably 1 to 50 mass%, and more preferably 1 to 40 mass%, based on the total content of copper, zinc oxide, and alumina. The copper content here means the amount of copper component contained in the copper-based catalyst body converted into the amount of metallic copper.

[0047] A copper-based catalyst body containing a copper component and zinc oxide can be obtained, for example, by a method including a step of forming a precipitate containing copper and zinc by coprecipitation and a step of calcining the formed precipitate. The precipitate includes, for example, hydroxides, carbonates, or composite salts of copper and zinc. A copper-based catalyst body containing a copper component, zinc oxide, and a support can be obtained by forming a precipitate containing copper and zinc by coprecipitation from a solution containing a support (e.g., alumina).

[0048] The calcined body containing the copper component and zinc oxide formed by calcination may be powdered, and the powder may be further molded to form a granular compact. Examples of methods for molding the powder include extrusion molding and tablet molding. A molded body can also be obtained by molding a mixture containing the powder of the calcined body and carbon black.

[0049] The FT catalyst 16a is preferably an iron-based catalyst body containing an iron component including metallic iron, iron oxide, or both, and at least one additive metal selected from the group consisting of alkali metals and alkaline earth metals. Alternatively, the FT catalyst 16a may be an iron-copper-based catalyst body containing a copper component in addition to the iron component. While the iron-based catalyst body functions as a catalyst, it typically contains at least metallic iron. Therefore, the catalyst is typically subjected to a reduction treatment before being used in a reaction. Before the reduction treatment, the iron-based catalyst body typically contains iron oxide (e.g., Fe3O4 or Fe2O3).

[0050] The content of iron components in the iron-based catalyst body is preferably 5 to 100 mass % based on the mass of the entire iron-based catalyst body when the amount of iron components contained in the iron-based catalyst body is converted into the amount of iron oxide.

[0051] The added metal includes one or more types arbitrarily selected from alkali metals. For example, the added metal preferably includes at least one type selected from the group consisting of sodium, potassium, and cesium. Of course, two or more types of added metals may be used. When the added metal includes sodium, potassium, or cesium, liquid hydrocarbons can be produced more efficiently.

[0052] The content of the additive metal in the iron-based catalyst body is preferably 0.2 to 40 mass%, and more preferably 0.5 to 20 mass%, based on the amount of the portion of the iron-based catalyst body other than the additive metal. When the additive metal includes sodium, the content of sodium in the iron-based catalyst body is preferably 0.2 to 20 mass%, and more preferably 0.5 to 10 mass%. When the additive metal includes potassium, the content of potassium in the iron-based catalyst body is preferably 0.2 to 40 mass%, and more preferably 0.5 to 20 mass%. When the additive metal includes cesium, the content of cesium in the iron-based catalyst body is preferably 0.2 to 20 mass%, and more preferably 0.5 to 10 mass%. When the content of the additive metal is within the above range, the conversion rate of carbon monoxide to hydrocarbons tends to be further improved.

[0053] The iron-based catalyst body is, for example, Fe 3+ The iron(III) oxide powder can be obtained by a method comprising the steps of: generating a precipitate of a hydroxide containing trivalent iron from an aqueous solution containing the metal; calcining the precipitate to form a powder containing ferric oxide; mixing the powder with an aqueous solution containing an additive metal; and then drying the aqueous solution containing the additive metal.

[0054] The powder containing ferric oxide may be further molded to form a granular compact. Examples of methods for molding the powder include extrusion molding and tablet molding. A mixture containing the sintered powder and carbon black may also be molded to obtain a compact.

[0055] Each catalyst may be heated while the reaction for producing hydrocarbons from the raw material gas proceeds. The heating temperature for the reaction is, for example, 200 to 400° C. The raw material gas may contain only carbon dioxide or carbon monoxide, or may be a mixed gas containing carbon dioxide and carbon monoxide. [Example]

[0056] The present invention will be described in more detail below with reference to examples, although the present invention is not limited to these examples.

[0057] Example 1 [Preparation of copper-based catalyst: reverse shift catalyst 14a] 5.0 g of γ-alumina (Sumitomo Chemical Co., Ltd., BK-105) was suspended in 1.0 L of purified water by stirring with a homomixer. 300 mL of an aqueous solution containing 31.7 g of copper nitrate hydrate (Nacalai Reagent Co., Ltd.) and 38.1 g of zinc nitrate hydrate (Nacalai Reagent Co., Ltd.) was quickly added to the resulting suspension at room temperature, and the suspension was then stirred for an additional 1 hour. Subsequently, while continuing to stir with the homomixer, 300 mL of an aqueous solution containing 35.0 g of sodium carbonate (Fujifilm Wako Pure Chemical Industries, Ltd.) was added dropwise at a rate of 5 mL / min using a roller pump at room temperature. The resulting suspension containing the precipitate was then allowed to stand at 35°C for 24 hours for aging. The supernatant was removed from the aged suspension by decanting, and the remaining precipitate was diluted again with water. This decanting and dilution process was repeated four times.

[0058] The precipitate was then removed by suction filtration, suspended again in pure water, and then removed by suction filtration. This procedure was repeated four times. The precipitate was thoroughly washed with water. The resulting precipitate was dried by heating at 120°C for 24 hours. The dried precipitate was calcined by heating under air flow in the following order: 150°C for 1 hour, 200°C for 1 hour, 250°C for 1 hour, 300°C for 1 hour, 350°C for 1 hour, and 400°C for 4 hours. Calcination yielded a black powder, which was a copper-based catalyst containing copper components and zinc oxide. This black powder was pulverized in a mortar and molded at a pressure of 40 MPa to obtain a cylindrical copper-based catalyst body with a diameter of 3 mm and a height of 3 mm.

[0059] [Preparation of iron-based catalyst: FT catalyst 16a] A solution with an iron ion concentration of 3 mol / L was prepared by dissolving 146.9 g of iron nitrate nonahydrate (Fujifilm Wako Pure Chemical Industries, Ltd.) in 120 mL of purified water with stirring at 70 °C. A sodium hydroxide solution (16.6 mol / L) prepared by dissolving 47.9 g of sodium hydroxide in 70 mL of purified water was added dropwise to the solution to adjust the pH to 11–12, producing a solution containing a precipitate of iron(III) hydroxide (Fe(OH)3). The precipitate was filtered using a vacuum pump, and the resulting filtrate was repeatedly washed until the alkali metal content was below a predetermined level. This is because if a large amount of alkali metal remained (unspecified), it would be difficult to adjust the amount of alkali metal to be supported on the ferric oxide support in the subsequent alkali metal addition step.

[0060] The resulting precipitate was then dried by heating at 120°C for 12 to 20 hours. The dried precipitate was calcined by finally heating at 400°C for 5 hours while increasing the ambient temperature at a rate of 5°C / min under air flow. As a result, 28.7 g of ferric oxide (Fe2O3) was obtained.

[0061] Next, 5 g of the obtained ferric oxide was dissolved in an aqueous sodium hydroxide solution or an aqueous sodium nitrate solution, dried at 120°C for 12 to 20 hours, and finally calcined by heating at 400°C for 5 hours while increasing the ambient temperature at a rate of 5°C / min under air flow. This yields a powder of an iron-based catalyst body containing a support mainly composed of ferric oxide and an alkali metal supported on the support. Note that when ferric oxide is dissolved in an aqueous sodium hydroxide solution, the calcination step may be omitted and only the drying step may be performed. The powder is then molded to obtain a molded body of a predetermined shape. The iron-based catalyst body in each of the following examples is in the form of flakes with a diameter of 2 to 3 mm.

[0062] When potassium is to be supported on ferric oxide as the alkali metal, an aqueous solution of potassium hydroxide or potassium nitrate may be used, and when cesium is to be supported on ferric oxide as the alkali metal, an aqueous solution of cesium hydroxide or cesium nitrate may be used.

[0063] [Preparation of cobalt-based catalyst: FT catalyst 16a] 1.23 g of cobalt nitrate hexahydrate was dissolved in 1.50 g of pure water. The resulting aqueous solution was impregnated into 4 g of spherical alumina (KHA-24, manufactured by Sumitomo Chemical Co., Ltd.) and dried overnight at 110°C. This impregnation and drying process was repeated twice to obtain a cobalt-based catalyst (Al-supported Co-based catalyst) in which 12.5 mass% of cobalt was supported on the alumina support.

[0064] [Reduction treatment of each catalyst] Each catalyst was packed sequentially into a fixed-bed reactor tube with an inner diameter of 1.27 cm, and arranged in the following order from the gas inlet side (upstream) of the reactor tube: copper-based catalyst, iron-based catalyst, and cobalt-based catalyst. Subsequently, a flow gas consisting of 1% by volume hydrogen and nitrogen was circulated through the reactor tube at a flow rate of 200 Ncc / min under atmospheric pressure, while the temperature of the catalyst was raised from room temperature to 150°C over 1 hour. While maintaining the temperature at 150°C, the hydrogen concentration in the flow gas was sequentially changed to 2%, 10%, 20%, 50%, and 100% by volume. After changing to a flow gas (hydrogen gas) with a hydrogen concentration of 100% by volume, the flow state was maintained for 2 hours. Subsequently, while continuing to flow hydrogen gas, the temperature of the catalyst was raised to 350°C at a rate of 200°C / hour and maintained at 350°C for 7 hours, thereby reducing the catalyst.

[0065] Example 2 [Preparation of iron-based catalyst: FT catalyst 16a] In Example 2, triiron tetroxide (Fe3O4) was prepared as a support for an iron-based catalyst. 15.8 g of iron trichloride hexahydrate (Fujifilm Wako Pure Chemical Industries, Ltd.) and 6.3 g of iron dichloride tetrahydrate (Fujifilm Wako Pure Chemical Industries, Ltd.) were dissolved in a mixed solution of 75 mL of purified water and 2.5 mL of 35% hydrochloric acid at 60°C while stirring. 336 mL of 5% aqueous ammonia was added dropwise to the resulting solution while maintaining the temperature at 60°C, and the solution was then stirred for 1 hour. A precipitate formed in the solution. The supernatant was removed by decanting, and the remaining precipitate was filtered while washing with 400 mL of purified water. The resulting precipitate was dried by heating at 70°C for 6 hours. The resulting black powder was pulverized in a mortar. The fine powder was compacted under a pressure of 40 MPa to obtain a cylindrical compact containing Fe3O4, measuring 2 mm in diameter and 2 mm in height. 10 g of this compact was impregnated with an aqueous solution containing 0.17 g of sodium hydroxide (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) and 4.63 g of pure water, and the aqueous solution impregnated into the compact was dried by heating at 60°C for 18 hours to obtain an iron-based catalyst compact containing an iron-based catalyst (NaFe3O4). The ratio of sodium to Fe3O4 was calculated to be approximately 1 mass%.

[0066] Example 3 [Preparation of iron-copper catalyst: FT catalyst 16a] In Example 3, an iron-copper catalyst was prepared as an iron-containing catalyst. 34.6 g of iron nitrate nonahydrate and 2.3 g of copper nitrate trihydrate were dissolved in distilled water to prepare a 100 mL solution. Subsequently, while maintaining the temperature at 70°C, 5% aqueous ammonia was added dropwise until the pH reached 8. The amount added was 212 mL. The solution was further stirred at room temperature for 15 hours, and the resulting precipitate was filtered and washed with distilled water. The precipitate was dried by heating at 120°C for 6 hours. 8 g of the resulting powder was impregnated with an aqueous solution containing 0.55 g of sodium hydroxide (manufactured by Fujifilm Wako Pure Chemical Industries) and 3 g of pure water and dried at 60°C for 18 hours. The powder was then calcined at 350°C for 3 hours to obtain an iron-copper catalyst containing iron, copper, and sodium. The calculated sodium content of the iron-copper catalyst was approximately 4% by mass.

[0067] Although the present invention has been described above with reference to the above-mentioned embodiments and examples, the present invention is not limited to the above-mentioned embodiments and examples, and appropriate combinations or substitutions of the configurations of the embodiments and examples are also included in the present invention. Furthermore, based on the knowledge of those skilled in the art, it is possible to appropriately rearrange the combinations and processing orders in the embodiments and examples, and to make various design changes and other modifications to the embodiments, and such modified embodiments are also included in the scope of the present invention. [Explanation of symbols]

[0068] 10 Reactor, 12 Reactor, 14 First catalyst section, 14a Reverse shift catalyst, 16 Second catalyst section, 16a FT catalyst, 18 Inactive catalyst, 20, 30 Reactor, 40 Reactor, 42 Reactor, 44 Outer cylinder, 46 Inner cylinder, 48 Turn-back flow path, G Reactant gas, R End region, S Space.

Claims

1. a reactor configured to discharge hydrocarbons produced from a raw material gas introduced from an upstream inlet through a downstream outlet; a first catalyst section disposed inside the reactor and configured to generate carbon monoxide using hydrogen and carbon dioxide contained in the raw material gas; a second catalytic section disposed inside the reactor and configured to produce hydrocarbons using the carbon monoxide and the hydrogen produced in the first catalytic section; The second catalyst section has an upstream half region containing 10 to 50 mass % of an inert catalyst mixed therein, A reactor in which the amount of the inert catalyst in the second catalyst section is greater in the upstream half region than in the downstream half region.

2. 2. The reaction device according to claim 1, wherein the first catalyst portion contains at least one of copper and copper oxide.

3. 3. The reaction device according to claim 1, wherein the second catalyst portion includes a support containing at least one of iron and iron oxide, and an additive metal that is at least one metal selected from the group consisting of alkali metals and alkaline earth metals and is added to the support.

4. The reaction apparatus according to any one of claims 1 to 3, wherein the second catalyst section has an upstream half region in which the catalyst contained in the first catalyst section is mixed at 10 to 50 mass%.

5. 4. The reaction apparatus according to claim 3, wherein the amount of the added metal in the upstream half region of the second catalyst section is less than 10 mass % and the amount of the added metal in the downstream half region is 10 mass % or more.

6. 6. The reactor according to claim 1, wherein the first catalyst portion and the second catalyst portion are spaced apart from each other.

7. 7. The reaction apparatus according to claim 1, further comprising a flow straightening section provided between the first catalyst section and the second catalyst section, the flow straightening section straightening the flow of carbon monoxide from the first catalyst section to the second catalyst section.

8. a return flow path is provided between the first catalyst portion and the second catalyst portion, the first catalyst section is disposed on the upstream side of the turning flow path and on the outer circumferential side of the reactor, The reaction device according to claim 1 , wherein the second catalyst section is disposed downstream of the turn-back flow path and inside the first catalyst section.

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