Carbon monoxide production device and carbon monoxide production method

Abstract

The present invention addresses the problem of providing a device and method that efficiently produce carbon monoxide under lower temperature conditions by using a transition metal oxide-containing catalyst while avoiding the equilibrium constraints of the reverse water-gas shift reaction.　A carbon monoxide production device according to the present invention is characterized by producing carbon monoxide by bringing carbon dioxide into contact with a catalyst that contains a hydrogen reduction-treated transition metal oxide that can assume a plurality of oxidation numbers.

Description

Carbon monoxide production apparatus and carbon monoxide production method

[0001] The present invention relates to a carbon monoxide production apparatus and method utilizing the reverse water gas shift reaction.

[0002] In recent years, carbon dioxide (CO2) has been identified as a major cause of global warming, and reducing its emissions into the environment has become an urgent issue worldwide. To achieve this, it is important not only to reduce CO2 emissions into the atmosphere by improving the efficiency of existing processes, but also to develop a carbon dioxide capture and utilization (CCU) process that treats CO2 as a resource and converts it into fuels and chemicals for effective use. At the core of this process is the technology for producing synthesis gas, a mixture of carbon monoxide and hydrogen, from CO2. Processes for converting synthesis gas into liquid fuels and chemicals have already been established. If synthesis gas could be efficiently produced from exhaust gases and atmospheric CO2, it would be possible to produce liquid fuels and chemicals using CO2, which was previously discarded into the atmosphere, as a raw material.

[0003] Patent Document 1 provides a reverse shift reaction catalyst that has excellent durability at high temperatures, can suppress the generation of methanation reactions, and can efficiently generate a reverse shift reaction to efficiently produce a synthesis gas consisting of carbon monoxide and unreacted hydrogen with a low methane content, and a method for producing synthesis gas using the reverse shift reaction catalyst. The reverse shift reaction catalyst used to generate carbon monoxide and water vapor from carbon dioxide and hydrogen is composed of a composite oxide containing at least one alkaline earth metal selected from the group consisting of Ca, Sr, and Ba, and at least one transition metal selected from the group consisting of Ti and Zr. A raw material gas containing carbon dioxide and hydrogen is contacted with the reverse shift reaction catalyst at a temperature of 700°C or higher to cause the reverse shift reaction. The method for producing synthesis gas is characterized by comprising the steps of:

[0004] Restated WO2011 / 065194 publication

[0005] The reverse water gas shift reaction, shown in the following formula (1), is known as a method for producing synthesis gas from carbon dioxide. Carbon dioxide is reduced by reaction with hydrogen to produce carbon monoxide. ２ +H ２ →CO+H ２ O...(1) The reverse water-gas shift reaction is an equilibrium reaction, and as an endothermic reaction, high temperatures are advantageous. This is because the equilibrium constant of the reverse water-gas shift reaction increases with increasing temperature. Therefore, high temperatures of 750°C or higher are required, which requires high heat resistance in the catalyst and reactor, inevitably increasing the cost of the equipment. Furthermore, because the reverse water-gas shift reaction is a reversible reaction, there is an equilibrium constraint imposed by the generated water vapor, making it difficult to achieve a sufficient conversion rate. Furthermore, when the generated carbon monoxide is used, for example, for the synthesis of hydrocarbons by the Fischer-Tropsch process, the by-product water vapor must be removed by cooling (quenching) in the upstream stage of the Fischer-Tropsch reactor.

[0006] Therefore, an object of the present invention is to solve the above-mentioned problems and to provide an apparatus and a method for producing carbon monoxide efficiently at lower temperatures by avoiding the equilibrium constraints of the reverse water-gas shift reaction using a catalyst containing a transition metal oxide.

[0007] As a result of extensive research into the above-mentioned problems, the present inventors have discovered that by incorporating into a catalyst a transition metal oxide that can assume multiple oxidation states and has reversible oxygen deficiency, and that has been subjected to hydrogen reduction treatment, it is possible to avoid the equilibrium constraints of the reverse water-gas shift reaction and to efficiently produce carbon monoxide under lower temperature conditions, and have completed the present invention. That is, the present invention relates to the following carbon monoxide production apparatus and carbon monoxide production method.

[0008] The carbon monoxide production apparatus of the present invention, which solves the above problems, is characterized by producing carbon monoxide by bringing carbon dioxide into contact with a catalyst containing a transition metal oxide that has been subjected to hydrogen reduction and is capable of assuming multiple oxidation states. As a result, the oxidation-reduction effect of the transition metal oxide contained in the catalyst, which is capable of assuming oxidation states of tetravalent to hexavalent, avoids equilibrium constraints, making it possible to provide an apparatus for producing carbon monoxide efficiently under lower temperature conditions.

[0009] One embodiment of the carbon monoxide production apparatus of the present invention is an apparatus comprising two or more reactors filled with a catalyst containing a transition metal oxide that has been reduced by hydrogen and is capable of taking multiple oxidation states, wherein carbon dioxide is supplied to one reactor and brought into contact with the catalyst in that reactor to produce carbon monoxide, and hydrogen is supplied to another reactor and brought into contact with the catalyst in that reactor to reduce the catalyst in that reactor, and the supply of carbon dioxide or hydrogen can be switched so that the carbon monoxide production operation in one reactor and the catalyst reduction operation in the other reactor can be carried out alternately in the first and second reactors. With this configuration, one of the two or more reactors is always operated to produce carbon monoxide, making it possible to provide a continuous carbon monoxide production apparatus.

[0010] Furthermore, in one embodiment of the carbon monoxide production apparatus of the present invention, the catalyst contains at least one transition metal oxide selected from the group consisting of molybdenum, tungsten, cobalt, and iron. These transition metal oxides, which are hydrogen-reduced and can take on multiple oxidation states, have an oxidation-reduction effect in a high oxidation state, which avoids equilibrium constraints in the reverse water-gas shift reaction and enables the provision of an efficient carbon monoxide production apparatus at lower temperatures while suppressing carbon deposition from carbon monoxide due to the Boudouard reaction.

[0011] Additionally, in one embodiment of the carbon monoxide production apparatus of the present invention, the catalyst contains at least one transition metal oxide selected from the group consisting of molybdenum and tungsten. These transition metal oxides, which are capable of adopting multiple oxidation states and have been subjected to hydrogen reduction treatment, have an oxidation-reduction effect in a high oxidation state, thereby avoiding equilibrium constraints in the reverse water-gas shift reaction and more effectively suppressing carbon deposition from carbon monoxide due to the Boudouard reaction under low-temperature conditions, thereby enabling the provision of an efficient carbon monoxide production apparatus.

[0012] The carbon monoxide production method of the present invention, which solves the above problems, is characterized by producing carbon monoxide by bringing carbon dioxide into contact with a catalyst containing a transition metal oxide that can take multiple oxidation states and has been subjected to hydrogen reduction treatment. As a result, equilibrium constraints can be avoided due to the oxidation-reduction effect of the transition metal oxide, which can take tetravalent to hexavalent oxidation states and has been subjected to hydrogen reduction treatment, contained in the catalyst, and this makes it possible to provide a carbon monoxide production method that can be performed at lower temperatures and is efficient.

[0013] According to the present invention, by using a catalyst containing a transition metal oxide to avoid equilibrium constraints in the reverse water gas shift reaction, it is possible to provide an efficient carbon monoxide production apparatus and method while suppressing carbon deposition from carbon monoxide due to the Boudouard reaction under lower temperature conditions.

[0014] FIG. 1 is a schematic explanatory diagram of a reactor of a carbon monoxide manufacturing apparatus of the present invention. FIG. 2 is an explanatory diagram of a carbon monoxide manufacturing apparatus according to a second embodiment of the present invention. FIG. 3 is an explanatory diagram of a gas introduction mechanism according to the second embodiment of the present invention. FIG. 4 is an explanatory diagram of a gas delivery mechanism according to the second embodiment of the present invention. FIG. 5 is a conceptual explanatory diagram of an oxidation-reduction reaction of a transition metal oxide of the present invention. FIG. 6 is an explanatory diagram of a modified example of a carbon monoxide manufacturing apparatus according to the second embodiment of the present invention. FIG. 7 is an explanatory diagram of a modified example of a carbon monoxide manufacturing apparatus according to the second embodiment of the present invention. FIG. 8 is an explanatory diagram of a gas introduction mechanism according to a modified example of the second embodiment of the present invention. FIG. 9 is an explanatory diagram of a gas delivery mechanism according to a modified example of the second embodiment of the present invention.

[0015] The following describes in detail the embodiments of the present invention, but the present invention is not limited to these, and various modifications are possible within the scope of the description. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention.

[0016] [First Embodiment] FIG. 1 illustrates an outline of a reactor 10 of a carbon monoxide production apparatus according to a first embodiment of the present invention. The reactor 10 includes a reaction tower 11, which is a container forming the outer shell of the reactor 10, and a reaction catalyst 21 packed inside the reaction tower 11. The reaction catalyst 21 is a catalyst in which a catalytically active component and a co-catalyst are supported on a carrier. The catalyst in which the catalytically active component and the co-catalyst are supported on a carrier is packed inside the reaction tower 11 in the form of, for example, granules. Carbon dioxide is introduced into the reaction tower 11, and carbon monoxide is generated due to the reverse water gas shift reaction-promoting effect of the reaction catalyst 21. Depending on the conditions of the reactor 10, such as the temperature and pressure, and the performance of the reaction catalyst 21, not all of the carbon dioxide introduced into the reactor 10 is converted to carbon monoxide. Therefore, the gas discharged from the reaction tower 11 is a mixture of carbon monoxide and carbon dioxide.

[0017] The reaction catalyst 21 promotes the reverse water gas shift reaction, selectively produces carbon monoxide, and efficiently progresses the reverse water gas shift reaction. The catalytically active component constituting the reaction catalyst 21 is a transition metal oxide that can assume multiple oxidation states after hydrogen reduction. For example, the catalyst preferably contains at least one element selected from molybdenum, tungsten, cobalt, and iron as the active component, more preferably at least one element selected from the group consisting of molybdenum, tungsten, and cobalt, and most preferably either molybdenum or tungsten. The active component exists in the form of an oxide.

[0018] The co-catalyst constituting the reaction catalyst 21 has a function of promoting the adsorption of carbon dioxide or promoting the desorption of carbon monoxide due to its solid basicity. Examples of the co-catalyst that promotes the adsorption of carbon dioxide include K ２ O, Rb ２ O, Cs ２ O, MgO, BaO, ZnO, Y ２ O３ , La ２ O ３ , CeO ２ The promoter for promoting the desorption of carbon monoxide includes, for example, TiO ２ , ZrO ２ The catalyst 21 includes at least one oxide selected from the group consisting of Al, ２ O ３ , SiO ２ -Al ２ O ３ , SiO ２ The performance of the active component of the reverse water gas shift catalyst is improved by being supported on a support component.

[0019] The carbon monoxide production apparatus according to an embodiment of the present invention is a technology for decomposing carbon dioxide into carbon monoxide and oxygen using an oxygen-deficient transition metal oxide, which is a catalytically active component constituting the reaction catalyst 21 packed in the reactor 10, and recovering only the carbon monoxide. Because carbon dioxide is produced by reducing carbon dioxide through a stoichiometric reaction, a regeneration operation is required after the reaction to restore the oxygen deficiency of the transition metal oxide.

[0020] The technology for generating and recovering carbon monoxide of the present invention is carried out by the oxidation-reduction reaction of transition metal oxides, which are the active components of the catalyst. The water gas shift (WGS) reaction is a reversible reaction, and the reverse water gas shift (RWGS) reaction (CO ) generates carbon monoxide from carbon dioxide and hydrogen. ２ +H ２ →CO+H ２O(g)) occurs. The RWGS reaction requires high temperatures exceeding 700°C due to thermodynamic equilibrium (Patent Document 1). To use transition metal oxides as active components of catalysts effective for WGS and RWGS reactions, it is important that the oxygen atoms (O) of the transition metal oxide react with a reducing substance such as hydrogen to generate oxygen vacancies that exhibit oxidophilicity or oxygen affinity. Oxygen vacancies on the surface of transition metal oxides that exhibit oxidophilicity or oxygen affinity can acquire carbon dioxide reducibility. Reversible vacancies are generated when oxygen is forcibly extracted from the metal oxide by treatment under strong reducing conditions. Reversible vacancies are vacancies that allow oxygen atoms (O) to be incorporated into the vacant sites. When oxygen atoms (O) are again incorporated into the vacant sites, the vacancies disappear; however, oxygen vacancies are again generated by treatment under strong reducing conditions.

[0021] FIG. 5 is a conceptual diagram illustrating the oxidation-reduction reaction of the transition metal oxide of the present invention. In FIG. 5, the catalytically active component is molybdenum trioxide (MoO ３ The redox reaction will be explained in detail using the case where the clockwise reaction loop is the reverse water gas shift reaction (RWGS) that produces CO. ３ Is H ２ is reduced by MoO ３ Some of the oxygen atoms that make up water vapor (H ２ O(g)) and a partially reduced state of MoO with oxygen deficiency. ３－ｘ The charge balance shift due to oxygen deficiency is as follows: when the X value is 1, Mo becomes tetravalent (Mo ４＋ The oxygen vacancy site is compensated by becoming CO ２ The Mo species then extracts an oxygen atom (O) from the Mo atom to generate CO, and the Mo species becomes MoO ３ In this way, the oxygen vacancy site returns to the CO ２The reversible oxygen vacancy sites formed on the surface of molybdenum trioxide cause a redox reaction (redox) in which partial reduction by hydrogen and oxidation by carbon dioxide are repeated. By utilizing the redox that occurs at the reversible oxygen vacancy sites, the partially reduced MoO ３－ｘ For seeds, CO ２ By contacting with CO ２ One oxygen atom can be supplied to the oxygen vacancy site on the catalyst surface from the X value, thereby producing only CO. For efficient CO production, the X value is preferably 1 or 2, and 1 is most suitable.

[0022] By alternately performing the reduction step and the oxidation step of the surface of the transition metal oxide such as molybdenum trioxide, the surface is less susceptible to the equilibrium constraints of the reverse water-gas shift reaction. ３－Ｘ The X value is preferably 1 or 2, and most preferably 1. When the X value is 3, i.e., Mo ０ So, the Boudouard reaction (2CO → CO ２ This makes it possible to provide a carbon monoxide generating apparatus that generates carbon monoxide from carbon dioxide even at a reaction temperature of 400°C or higher and lower than 700°C while suppressing carbon deposition from carbon monoxide due to the Boudouard reaction.

[0023] The carbon monoxide production apparatus according to an embodiment of the present invention includes a hydrogen supply source and a carbon dioxide supply source. The hydrogen supply source supplies hydrogen gas to the reactor 10 via a gas introduction mechanism including piping and valves. The carbon dioxide supply source supplies carbon dioxide to the reactor 10 via a gas introduction mechanism including piping and valves.

[0024] The carbon dioxide supplied by the carbon dioxide supply source is not particularly limited and can be used without any restrictions, but examples thereof include carbon dioxide recovered from a thermal power plant, carbon dioxide recovered from a steam reformer, carbon dioxide recovered from the atmosphere, carbon dioxide transported through a pipeline, and at least one selected from carbon dioxide recovered from a combustion device, carbon dioxide recovered from a chemical plant, carbon dioxide recovered from a steel mill, and carbon dioxide recovered from a cement factory. The carbon dioxide may be recovered from a single device or from multiple devices. Carbon dioxide recovered from each supply source may be liquefied and stored, and the vaporized carbon dioxide may be supplied to the carbon monoxide production apparatus according to an embodiment of the present invention as needed.

[0025] The hydrogen supplied by the hydrogen supply source is not particularly limited and can be used without any restrictions. For example, at least one selected from hydrogen produced by steam reforming of hydrocarbons, hydrogen produced by electrolysis of water, and hydrogen recovered from exhaust gas of steelworks can be used. It is preferable to use renewable energy for water electrolysis. For example, hydrogen produced by steam reforming of hydrocarbons can be used, and surplus hydrogen from the synthesis of hydrocarbons by the Fischer-Tropsch process can also be used. Furthermore, in order to regenerate the catalytically active components constituting the reaction catalyst 21 packed in the reactor 10, hydrogen may be introduced into the reactor 10 and subjected to hydrogen reduction treatment, and then the hydrogen may be refluxed and used. Hydrogen from the hydrogen supply source is dried in a hydrogen drying unit (not shown) and then stored. The hydrogen is supplied to the carbon monoxide production apparatus according to an embodiment of the present invention as needed.

[0026] [Second Embodiment] Figure 2 is an explanatory diagram of a carbon monoxide production apparatus according to a second embodiment of the present invention. As described in the explanation of the first embodiment, the transition metal oxide of the catalytically active component reduces carbon dioxide through a stoichiometric reaction to produce carbon monoxide, and therefore a regeneration operation to recover oxygen deficiency in the transition metal oxide after the reaction is required. Therefore, in the carbon monoxide production apparatus according to the second embodiment, when the reactor is configured with two columns, reactor 10A and reactor 10B, carbon monoxide production operation and hydrogen reduction treatment of the transition metal oxide of the catalytically active component are alternately performed, thereby enabling continuous carbon monoxide production.

[0027] The carbon monoxide production apparatus according to the second embodiment of the present invention includes a reactor 10A, a reactor 10B, a gas introduction mechanism 31, and a gas delivery mechanism 32. The reactors 10A and 10B are filled with a reaction catalyst 21. FIG. 2(a) shows a state in which the reactor 10A performs hydrogen reduction of the transition metal oxide, which is a catalytically active component, and the reactor 10B performs carbon monoxide production operation. FIG. 2(b) shows the opposite state in which the reactor 10A performs carbon monoxide production operation and the reactor 10B performs hydrogen reduction of the transition metal oxide, which is a catalytically active component. The alternating operation of the reactors 10A and 10B is switched by the gas introduction mechanism 31 and the gas delivery mechanism 32 shown in FIGS. 2(a) and 2(b).

[0028] FIG. 3 is an explanatory diagram of a gas introduction mechanism 31 according to a second embodiment of the present invention. In FIGS. 3 and 4, the open and closed states of the valves are indicated by open valve symbols and closed valve symbols, respectively. The gas introduction mechanism 31 is composed of two paths: one for introducing hydrogen and one for introducing carbon dioxide. The piping used in these paths is shared by the two paths, and the introduced gas is switched by switching the valve. Hydrogen and carbon dioxide are introduced from the hydrogen supply source and carbon dioxide supply source described above. Furthermore, the hydrogen or carbon dioxide that has passed through the gas introduction mechanism 31 is introduced into the reactor 10A and the reactor 10B.

[0029] The gas introduction mechanism 31 includes four valves: a valve 31a, a valve 31b, a valve 31c, and a valve 31d. In FIG. 3( a), the valves 31a and 31d are in an open position. The valves 31b and 31c are in a closed position. As a result, hydrogen from the hydrogen supply source passes through the gas introduction mechanism 31 and is introduced into the reactor 10A, and carbon dioxide from the carbon dioxide supply source is introduced into the reactor 10B. Although not shown, by closing the valves 31a and 31d and opening the valves 31b and 31c, hydrogen from the hydrogen supply source is introduced into the reactor 10B through the gas introduction mechanism 31, and carbon dioxide from the carbon dioxide supply source is introduced into the reactor 10A.

[0030] 4 is an explanatory diagram of a gas delivery mechanism 32 according to a second embodiment of the present invention. The gas delivery mechanism 32 is composed of two paths: one path for delivering a mixed gas of carbon monoxide and carbon dioxide, and another path for delivering wet hydrogen. The piping used in these paths is shared by the two paths, and the gas to be delivered is switched by switching a valve. The gas that has undergone the carbon dioxide production reaction or the hydrogen reduction treatment of the transition metal oxide of the catalytically active component in the reactor 10A and the reactor 10B passes through the gas delivery mechanism 32 and is delivered to the outside.

[0031] The gas discharge mechanism 32 includes four valves: valve 32a, valve 32b, valve 32c, and valve 32d. In FIG. 3A, valves 32a and 32d are in a closed position. Valves 32b and 32c are in an open position. As a result, wet hydrogen from reactor 10A and a mixed gas of carbon monoxide and carbon dioxide from reactor 10B are discharged to the outside. Although not shown, by opening valves 32a and 32d and closing valves 32b and 32c, the mixed gas of carbon monoxide and carbon dioxide from water reactor 10A and wet hydrogen from reactor 10B are discharged to the outside.

[0032] While this embodiment illustrates a process comprising two reactors, a configuration comprising three or more reactors (n reactors) is also preferable, as shown in Figures 6 to 8. This is effective, for example, when the time required for the transition metal oxide reduction step differs from the time required for carbon monoxide production by contact with carbon dioxide. Figures 6 to 8 are explanatory diagrams of a carbon monoxide production apparatus according to a second embodiment, comprising three reactors 10A, 10B, and 10C. Figure 6 shows a carbon monoxide production operation in reactor 10A, and a hydrogen reduction treatment of the transition metal oxide of the catalytically active component in reactors 10B and 10C. Figure 7 shows a carbon monoxide production operation in reactor 10B, and a hydrogen reduction treatment of the transition metal oxide of the catalytically active component in reactors 10A and 10C. Figure 8 shows a carbon monoxide production operation in reactor 10C, and a hydrogen reduction treatment of the transition metal oxide of the catalytically active component in reactors 10A and 10B. FIG. 9 is an explanatory diagram of a gas introduction mechanism according to a modified example of the second embodiment. FIG. 10 is an explanatory diagram of a gas discharge mechanism according to a modified example of the second embodiment. The operation of the reactors 10A, 10B, and 10C is alternately switched by a gas introduction mechanism 33 and a gas discharge mechanism 34 shown in FIGS. 9 and 10. The indication of valve opening and closing in FIGS. 9 and 10 is the same as in the present embodiment in which the reactors have two columns, with open valve symbols indicating open and filled valve symbols indicating closed. The open / closed states of each valve and the operating states of the reactors 10A, 10B, and 10C can be replaced with the explanation for the case in which the reactors have two columns, and the explanation here will be omitted.

[0033] [Third embodiment] In a carbon monoxide generating apparatus according to a third embodiment of the present invention, the transition metal oxide serving as the catalytically active component in the reaction catalyst 21 is at least one transition metal oxide selected from the group consisting of molybdenum, tungsten, cobalt, and iron. In particular, when an oxide of molybdenum or tungsten is used as the catalytically active component, it is possible to provide a carbon monoxide generating apparatus that generates carbon monoxide from carbon dioxide even at a reaction temperature of 400°C or higher and lower than 700°C, while suppressing carbon deposition from carbon monoxide due to the Boudouard reaction. In particular, when an oxide of MoO ３－Ｘ and W.O.３―Ｘ The X value is preferably 1 or 2, and most preferably 1. When the X value is 3, that is, Mo ０ and W ０ is not preferred because it tends to reduce the ability to suppress the Boudouard reaction.

[0034] [Other Embodiments] A fourth embodiment of the present invention is a method for producing carbon monoxide, characterized in that carbon monoxide is produced by bringing carbon dioxide into contact with a catalyst containing a transition metal oxide that has been subjected to hydrogen reduction and is capable of taking multiple oxidation states. The configuration of the fourth embodiment is intended to be interpreted as a method by replacing the configuration of the apparatus of the first embodiment. Therefore, the description of the carbon monoxide production method in this embodiment can be replaced with the description of the features and operation of the carbon monoxide production apparatus of the first embodiment.

[0035] A fifth embodiment of the present invention is a carbon monoxide production method comprising two reactors filled with a catalyst, the method comprising the steps of supplying carbon dioxide to one reactor and bringing it into contact with the catalyst in the first reactor to perform a carbon monoxide production operation, and supplying hydrogen to the other reactor and bringing it into contact with the catalyst in the other reactor to perform a reduction operation of the catalyst in the other reactor, wherein the supply of carbon dioxide or hydrogen can be switched so that the carbon monoxide production operation in the first reactor and the catalyst reduction operation in the other reactor can be performed alternately in the first and other reactors. The configuration of the fifth embodiment is equivalent to the configuration of the apparatus in the second embodiment. Therefore, the description of the carbon monoxide production method in this embodiment can be replaced with the description of the features and operation of the carbon monoxide production apparatus of the second embodiment.

[0036] A sixth embodiment of the present invention is a method for producing carbon monoxide, characterized in that the catalyst contains an oxide of at least one transition metal selected from the group consisting of molybdenum, tungsten, cobalt, and iron. The configuration of the sixth embodiment is intended to be interpreted as a method by replacing the configuration of the apparatus of the third embodiment. Therefore, the description of the carbon monoxide production method in this embodiment can be replaced with the description of the features and operation of the carbon monoxide production apparatus of the third embodiment.

[0037] In each embodiment of the present invention, the use of a catalyst containing a transition metal oxide avoids the equilibrium constraint of the reverse water gas shift reaction, thereby providing an apparatus and method for producing carbon monoxide efficiently at lower temperatures. Furthermore, carbon deposition from carbon monoxide due to the Boudouard reaction can be suppressed, enabling more efficient carbon monoxide production.

[0038] 10, 10A, 10B, 10C, reactor, 11 reaction tower, 21 reaction catalyst, 31 gas introduction mechanism, 31a, 31b, 31c, 31d valve, 32 gas discharge mechanism, 32a, 32b, 32c, 32d valve, 33 gas introduction mechanism, 33a, 33b, 33c, 33d, 33e, 33f, 33g, 33f valve, 34 gas discharge mechanism, 34a, 34b, 34c, 34d, 34e, 34f, 34g valve

Claims

1. A carbon monoxide production device that produces carbon monoxide by contacting carbon dioxide with a catalyst containing a transition metal oxide that can take multiple oxidation states and has been subjected to hydrogen reduction treatment.

2. A carbon monoxide production apparatus having two or more reactors filled with a catalyst containing a transition metal oxide that can take multiple oxidation numbers and has been reduced with hydrogen, wherein carbon dioxide is supplied to one of the reactors and brought into contact with the catalyst in the first reactor to produce carbon monoxide, and hydrogen is supplied to another of the reactors and brought into contact with the catalyst in the other of the reactors to reduce the catalyst in the other of the reactors, and the supply of carbon dioxide or hydrogen can be switched so that the carbon monoxide production operation in the one of the reactors and the reduction operation of the catalyst in the other of the reactors can be performed alternately in the one and other of the reactors.

3. The carbon monoxide generating apparatus according to claim 1 or 2, characterized in that the catalyst contains an oxide of at least one transition metal selected from the group consisting of molybdenum, tungsten, cobalt and iron.

4. The carbon monoxide production apparatus according to claim 1 or 2, characterized in that the catalyst contains at least one transition metal oxide selected from the group consisting of molybdenum and tungsten.

5. A method for producing carbon monoxide, comprising the steps of: bringing carbon dioxide into contact with a catalyst containing a transition metal oxide that can take multiple oxidation states and has been subjected to hydrogen reduction treatment to produce carbon monoxide.

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