Carbon recycling equipment and carbon recycling method

Abstract

To provide carbon recycling equipment that can improve the reaction efficiency of carbon resource conversion reactions. [Solution] The system comprises a carbon resource conversion device (oxidation-reduction device 2) that converts carbon-containing gas into resources through a carbon resource conversion reaction (oxidation-reduction reaction), a catalytic reduction device 3 having a catalyst capable of absorbing and reducing carbon dioxide, an off-gas line 41 that introduces off-gas containing carbon dioxide from the carbon resource conversion device to the catalytic reduction device 3, and a reducing gas line 43 that introduces reducing gas to the catalytic reduction device 3. The system is configured to introduce a gas containing carbon monoxide, which is produced by the action of the catalyst by introducing the off-gas and reducing gas into the catalytic reduction device 3, from the catalytic reduction device 3 to the carbon resource conversion device.

Description

[Technical Field]

[0001] This invention relates to a carbon recycling facility and a carbon recycling method that utilize carbon-containing gas as a raw material gas. [Background technology]

[0002] As a carbon recycling technology, there is a known method that combines the reverse water-gas shift reaction (CO2 + H2 → CO + H2O) and the Boudouar reaction (2CO → C + CO2) to produce solid carbon from carbon dioxide (see, for example, Patent Document 1).

[0003] Patent Document 1 discloses equipment for recycling off-gas from a solid carbonization reactor that converts carbon monoxide into solid carbon via the Booduor reaction back into the solid carbonization reactor. In this equipment, the off-gas from the solid carbonization reactor contains unreacted carbon monoxide that was not converted into solid carbon. Therefore, by recycling the off-gas from the solid carbonization reactor as a raw material gas for the Booduor reaction, the yield of solid carbonization can be improved. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2024-54920 [Overview of the project] [Problems that the invention aims to solve]

[0005] In the equipment described in Patent Document 1, the off-gas from the solid carbonization reactor contains carbon dioxide produced as a by-product by the Boudouar reaction, in addition to unreacted carbon monoxide. Therefore, if the carbon dioxide in the off-gas from the solid carbonization reactor inhibits the redox reaction (Boudouar reaction) in the solid carbonization reactor, the reaction efficiency of the redox reaction will decrease, and the efficiency of solid carbon production will decrease.

[0006] In carbon recycling facilities, such as those described in Patent Document 1, there is a need to improve the reaction efficiency when converting carbon-containing gases into resources such as solid carbon through carbon resource conversion reactions such as oxidation-reduction reactions.

[0007] This invention has been made in view of the above-mentioned problems, and aims to provide carbon recycling equipment and a carbon recycling method that can improve the reaction efficiency of carbon resource conversion reactions. [Means for solving the problem]

[0008] The characteristic configuration of the carbon recycling equipment according to the present invention, which solves the above problems, is as follows: A carbon resource conversion device that converts carbon-containing gases into resources through a carbon resource conversion reaction, A catalytic reduction apparatus having a catalyst capable of absorbing and reducing carbon dioxide, An off-gas line for introducing off-gas containing carbon dioxide from the carbon resource recovery device to the catalytic reduction device, A reducing gas line for introducing reducing gas to the catalyst reduction device, Equipped with, The system is configured such that the off-gas and the reducing gas are introduced into the catalytic reduction device, and the gas containing carbon monoxide produced by the action of the catalyst is then introduced from the catalytic reduction device to the carbon resource recovery device.

[0009] In this carbon recycling system, off-gas containing carbon dioxide from the carbon resource recovery device is introduced to the catalytic reduction device via an off-gas line, and reducing gas is introduced to the catalytic reduction device via a reducing gas line. In the catalytic reduction device, the carbon dioxide contained in the off-gas is absorbed by the catalyst, and carbon monoxide is produced by a reduction reaction when the reducing gas comes into contact with the catalyst that has absorbed the carbon dioxide. The gas containing the carbon monoxide produced in the catalytic reduction device is then introduced from the catalytic reduction device to the carbon resource recovery device. With this carbon recycling system, even if the off-gas from the carbon resource recovery device contains carbon dioxide, the catalyst in the catalytic reduction device produces carbon monoxide from the carbon dioxide and reducing gas, and the gas containing the produced carbon monoxide is used as a raw material gas for carbon resource recovery reactions, including oxidation-reduction reactions, in the carbon resource recovery device, thereby improving the reaction efficiency of carbon resource recovery reactions, including oxidation-reduction reactions.

[0010] In the carbon recycling equipment according to the present invention, The carbon-containing gas preferably includes carbon dioxide and / or carbon monoxide.

[0011] With this carbon recycling equipment configuration, if the carbon-containing gas contains carbon dioxide, the carbon resource recovery device cannot directly produce resources such as solid carbon or hydrocarbon fuels such as methane from the carbon dioxide in the carbon-containing gas. However, carbon monoxide is produced in the catalytic reduction device from the carbon dioxide and reducing gas in the carbon-containing gas. As a result, the gas containing the produced carbon monoxide can be used as a raw material gas for the carbon resource recovery reaction in the carbon resource recovery device. On the other hand, if the carbon-containing gas contains carbon monoxide, the carbon resource recovery device can directly produce resources such as solid carbon and fuel by using this carbon-containing gas containing carbon monoxide as a raw material gas for the carbon resource recovery reaction. In this way, resources such as solid carbon and fuel can be produced using carbon-containing gas containing carbon dioxide and / or carbon monoxide as a raw material gas.

[0012] In the carbon recycling equipment according to the present invention, The reducing gas preferably contains hydrogen.

[0013] According to the carbon recycling equipment of this configuration, carbon monoxide can be efficiently generated by the reaction of carbon dioxide with hydrogen contained in the reducing gas in the catalytic reduction device.

[0014] In the carbon recycling equipment according to the present invention, It is preferable that a moisture removal device for removing moisture in the off-gas is provided in the off-gas line.

[0015] When the concentration of moisture contained in the off-gas introduced from the carbon resource conversion device to the catalytic reduction device via the off-gas line is high, water may adsorb on the catalyst and inhibit the reduction reaction of carbon dioxide. According to the carbon recycling equipment of this configuration, since the moisture in the off-gas is removed in advance by the moisture removal device provided in the off-gas line, it is possible to prevent the reduction reaction of carbon dioxide by the catalyst from being inhibited by water.

[0016] In the carbon recycling equipment according to the present invention, It is preferable that a hydrogen separation device for separating hydrogen in the off-gas is provided in the off-gas line.

[0017] According to the carbon recycling equipment of this configuration, unreacted hydrogen contained in the off-gas introduced from the carbon resource conversion device to the catalytic reduction device via the off-gas line can be separated and recovered by the hydrogen separation device.

[0018] In the carbon recycling equipment according to the present invention, It is preferable that the hydrogen separated by the hydrogen separation device is configured to be introduced into the carbon resource conversion device.

[0019] According to the carbon recycling equipment of this configuration, since the hydrogen separated by the hydrogen separation device is introduced into the carbon resource conversion device, the carbon resource conversion reaction in the carbon resource conversion device will be carried out in a reducing atmosphere, and the carbon resource conversion reaction can be promoted.

[0020] In the carbon recycling equipment according to the present invention, It is preferable that the hydrogen separated by the hydrogen separation device is configured to be used as the reducing gas.

[0021] According to the carbon recycling equipment of this configuration, since the hydrogen separated by the hydrogen separation device is used as the reducing gas introduced into the catalytic reduction device, the unreacted hydrogen contained in the off-gas can be effectively utilized.

[0022] In the carbon recycling equipment according to the present invention, It is preferable that a hydrogen separation device for separating hydrogen in the gas is provided in the gas line through which the gas after carbon dioxide is occluded by the catalyst flows.

[0023] According to the carbon recycling equipment of this configuration, since the gas after carbon dioxide is reduced by the occlusion of carbon dioxide by the catalyst is introduced into the hydrogen separation device, even when a hydrogen separation device with low separation performance between carbon dioxide and hydrogen is adopted, the unreacted hydrogen contained in the gas after carbon dioxide is occluded by the catalyst can be efficiently recovered.

[0024] In the carbon recycling equipment according to the present invention, It is preferable that the hydrogen separated by the hydrogen separation device is configured to be used as the reducing gas.

[0025] According to the carbon recycling equipment of this configuration, since the hydrogen separated by the hydrogen separation device is used as the reducing gas introduced into the catalytic reduction device, the unreacted hydrogen contained in the gas after carbon dioxide is occluded by the catalyst can be effectively utilized.

[0026] In the carbon recycling equipment according to the present invention, It is preferable that the gas after carbon dioxide has been absorbed by the catalyst is introduced into the catalytic reduction device, thereby generating carbon monoxide through the action of the catalyst.

[0027] With this carbon recycling equipment configuration, the unreacted hydrogen contained in the gas after carbon dioxide has been absorbed by the catalyst is used as a reducing gas introduced into the catalytic reduction unit. Therefore, it is possible to effectively utilize unreacted hydrogen with a simple configuration without having to use unreacted hydrogen separated in a hydrogen separation unit as a reducing gas.

[0028] In the carbon recycling equipment according to the present invention, It is preferable that the carbon resource recovery device is configured to use the reaction heat to maintain the temperature necessary for the reduction reaction in the catalytic reduction device.

[0029] With this carbon recycling equipment configuration, by utilizing the reaction heat in the carbon resource conversion device, the thermal energy required to maintain the temperature necessary for the reduction reaction in the catalytic reduction device can be reduced, thereby lowering energy costs.

[0030] In the carbon recycling equipment according to the present invention, The catalyst is preferably a binary functional catalyst comprising a composite of at least one selected from the group consisting of indium, copper, platinum, palladium, and zinc, an alkali metal, and a support.

[0031] According to this carbon recycling equipment configuration, the dual-function catalyst used in the catalytic reduction device includes a composite of at least one element selected from the group consisting of indium, copper, platinum, palladium, and zinc, an alkali metal, and a support. The indium and other elements, along with the alkali metal, act as active sites, enabling the catalyst to exhibit both carbon dioxide storage and reduction functions (reducing the stored carbon dioxide to carbon monoxide) in the reverse water-gas shift reaction. Furthermore, this dual-function catalyst exhibits superior carbon dioxide storage and reduction functions (reducing the stored carbon dioxide to carbon monoxide) even when the gas to be treated contains carbon monoxide in addition to carbon dioxide. As a result, a greater amount of carbon monoxide can be produced from carbon dioxide. In addition, for example, if the carbon monoxide produced in the reverse water-gas shift reaction is reduced to solid carbon by the Boudouar reaction, a large amount of solid carbon can be produced. Furthermore, since the reverse water-gas shift reaction using this dual-function catalyst has a lower reaction temperature than the Boudouar reaction, the reverse water-gas shift reaction is not the rate-limiting step, and energy consumption can be reduced.

[0032] In the carbon recycling equipment according to the present invention, The carbon resource conversion reaction is preferably a redox reaction.

[0033] With this carbon recycling equipment configuration, for example, if carbon monoxide is contained in the carbon-containing gas, solid carbon can be produced as a resource through a redox reaction using the carbon-containing gas as the raw material gas.

[0034] Next, the characteristic configuration of the carbon recycling method according to the present invention for solving the above problems is as follows: A carbon resource conversion process that converts carbon-containing gases into resources through a carbon resource conversion reaction, A carbon dioxide storage step involves contacting a catalyst with an off-gas containing carbon dioxide to cause the catalyst to absorb carbon dioxide, A carbon monoxide generation step involves contacting a reducing gas with the catalyst that has absorbed carbon dioxide to generate carbon monoxide, It includes, The carbon resource utilization process is carried out using the gas containing carbon monoxide generated as a result of the carbon dioxide storage process and the carbon monoxide generation process.

[0035] According to this carbon recycling method, by contacting a catalyst with an off-gas containing carbon dioxide, and then contacting the catalyst, which has absorbed the carbon dioxide, with a reducing gas, the resulting gas containing carbon monoxide is used as a raw material gas for the carbon resource conversion reaction. Therefore, the reaction efficiency of the carbon resource conversion reaction using a carbon-containing gas as a raw material gas can be improved. [Brief explanation of the drawing]

[0036] [Figure 1] Figure 1 is a block diagram showing the schematic configuration of a carbon recycling facility according to the first embodiment of the present invention. [Figure 2] Figure 2 is a block diagram showing the schematic configuration of a carbon recycling facility according to the second embodiment of the present invention. [Figure 3] Figure 3 is a block diagram showing the schematic configuration of a carbon recycling facility according to the third embodiment of the present invention. [Figure 4] Figure 4 is a block diagram showing the schematic configuration of a carbon recycling facility according to the fourth embodiment of the present invention. [Figure 5] Figure 5 is a block diagram showing the schematic configuration of a carbon recycling facility according to the fifth embodiment of the present invention. [Figure 6] Figure 6 is a block diagram showing the schematic configuration of a carbon recycling facility according to another embodiment 1. [Figure 7] Figure 7 is a block diagram showing the schematic configuration of a carbon recycling facility according to another embodiment 2. [Figure 8] Figure 8 is a block diagram showing the schematic configuration of a carbon recycling facility according to another embodiment 3. [Modes for carrying out the invention]

[0037] The present invention will be described below with reference to the drawings. In the following embodiments, a carbon recycling facility and carbon recycling method will be described as an example in which a carbon-containing gas is used as a raw material gas and a carbon recycling facility is used as an example in which a carbon resource conversion reaction is performed by an oxidation-reduction reaction to convert the carbon-containing gas into a resource (solid carbon). However, the present invention is not intended to be limited to the embodiments and configurations described below or shown in the drawings. In the following description, the carbon-containing gas line 10, gas lines 41-44, gas lines 51-55, and gas lines 61-63 are gas pipelines composed of necessary pipes, ducts, etc.

[0038] [First Embodiment] <Overall Structure> Figure 1 is a block diagram illustrating the schematic configuration of a carbon recycling facility 1A according to the first embodiment of the present invention. Figure 1(a) shows the case when the switching valves 33 and 34 are in the first switching state, and Figure 1(b) shows the case when the switching valves 33 and 34 are in the second switching state. The carbon recycling facility 1A shown in Figures 1(a) and (b) comprises an oxidation-reduction reactor 2 and a catalytic reduction device 3. The oxidation-reduction reactor 2 corresponds to the "carbon resource recovery device" of the present invention.

[0039] <Redox reaction apparatus> The redox reactor 2 has a gas inlet 2a and a gas outlet 2b, and is mainly composed of a reactor filled with a catalyst (for example, an iron-based metal catalyst) that promotes the redox reaction (Boudouar reaction). Both reduction and oxidation of carbon monoxide are carried out inside the reactor. The redox reactor 2 uses a carbon-containing gas supplied via a carbon-containing gas line 10 connected to the gas inlet 2a as a raw material gas, and produces solid carbon by the Boudouar reaction (2CO → C + CO2). In the redox reactor 2, carbon monoxide is passed through the reactor, causing carbon to precipitate on the catalyst surface inside the reactor. The gas temperature inside the redox reactor 2 is, for example, 300 to 1000°C, preferably 450 to 850°C (in this example, about 500°C). It is preferable that the carbon-containing gas supplied to the redox reactor 2 is preheated by a heater (not shown). Furthermore, while it may not be necessary to heat the catalyst using a heating furnace or the like inside the redox reaction apparatus 2, a configuration that uses a heating furnace or the like to heat the catalyst may be adopted as needed.

[0040] In this example, the carbon-containing gas is obtained, for example, from combustion exhaust gas from a waste incineration facility that has undergone exhaust gas treatment, after being treated in a carbon dioxide recovery device (not shown) and a reverse water-gas shift reactor (not shown), and is supplied to the oxidation-reduction reactor 2 via the carbon-containing gas line 10.

[0041] Here, carbon dioxide recovery devices are devices that recover carbon dioxide contained in combustion exhaust gas, and include devices that utilize chemical absorption, membrane separation, physical absorption, and solid absorption methods. A carbon dioxide recovery device using the chemical absorption method, for example, uses an amine absorbent and is configured to chemically bond (react) carbon dioxide in the exhaust gas with an amine to separate and recover only the carbon dioxide. A carbon dioxide recovery device using the membrane separation method uses a solid thin film with separation function and is configured to separate and recover carbon dioxide from the exhaust gas by utilizing its permeation selectivity. A carbon dioxide recovery device using the physical absorption method is configured to separate and recover carbon dioxide in the exhaust gas by dissolving it in a liquid. A carbon dioxide recovery device using the solid absorption method is configured to separate and recover carbon dioxide in the exhaust gas by adsorbing it onto the adsorbent, using zeolite or activated carbon as a physical adsorbent, or using an inorganic porous material supporting alkali metals or amines as a chemical adsorbent.

[0042] On the other hand, the reverse water-gas shift reactor uses a mixed gas of carbon dioxide-containing gas recovered by a carbon dioxide recovery device and hydrogen-containing gas from a hydrogen supply source (not shown) as raw material gas to produce carbon monoxide and water through a reverse water-gas shift reaction (CO2 + H2 → CO + H2O). The reverse water-gas shift reactor mainly consists of a reactor filled with a catalyst (for example, a copper-based metal catalyst) that promotes the reverse water-gas shift reaction, and both reduction of carbon dioxide and oxidation of hydrogen occur inside the reactor. In the reverse water-gas shift reactor, carbon monoxide and water (water vapor) are produced inside the reactor by passing carbon dioxide and hydrogen through the reactor, and carbon monoxide and water (water vapor) are discharged from the reactor. The gas temperature inside the reverse water-gas shift reactor is, for example, 300 to 1000°C, preferably 450 to 850°C (about 500°C in this example). Furthermore, it is preferable to preheat the carbon-containing gas supplied to the reverse water-gas shift reactor using a heater (not shown). In addition, it may not be necessary to heat the catalyst using a heating furnace or the like inside the reverse water-gas shift reactor, but a configuration that heats the catalyst using a heating furnace or the like may be adopted if necessary.

[0043] In this example, the carbon-containing gas supplied to the redox reactor 2 via the carbon-containing gas line 10 includes carbon dioxide recovered in the carbon dioxide recovery unit, carbon monoxide produced by the reverse water-gas shift reaction in the reverse water-gas shift reactor, unreacted hydrogen not used in the reverse water-gas shift reaction in the reverse water-gas shift reactor, and water (water vapor) produced as a by-product of the reverse water-gas shift reaction.

[0044] <Catalytic Reduction Device> The catalytic reduction apparatus 3 comprises a first reactor 31, a second reactor 32, a first switching valve 33, and a second switching valve 34.

[0045] The first reactor 31 has a gas inlet 31a and a gas outlet 31b, and is filled with a catalyst that can absorb and reduce carbon dioxide. The second reactor 32 has basically the same configuration as the first reactor 31, and has a gas inlet 32a and a gas outlet 32b, and is filled with a catalyst that can absorb and reduce carbon dioxide. In each reactor 31 and 32, carbon dioxide contained in the off-gas (described later) is absorbed by the catalyst, and carbon monoxide is produced by a reduction reaction when a reducing gas containing hydrogen comes into contact with the catalyst that has absorbed carbon dioxide. The produced carbon monoxide, unreacted hydrogen, and water (water vapor) produced as a by-product of the reduction reaction are discharged. The gas temperature inside each reactor 31 and 32 is, for example, 200 to 700°C, preferably 300 to 500°C (about 350°C in this example). It is preferable that the gas supplied to each reactor 31 and 32 is preheated by a heater (not shown). Furthermore, while it may not be necessary to heat the catalyst using a heating furnace or the like inside each reactor 31, 32, a configuration that uses a heating furnace or the like to heat the catalyst may be adopted as needed.

[0046] <Catalyst> In each reactor 31, 32, it is preferable to use a binary functional catalyst that has both an adsorption function for adsorbing carbon dioxide contained in the off-gas and a reduction function for reducing the adsorbed carbon dioxide to carbon monoxide. The binary functional catalyst comprises a composite of at least one selected from the group consisting of indium, copper, platinum, palladium, and zinc, an alkali metal, and a support. More specifically, the binary functional catalyst is a composite in which at least one selected from the group consisting of indium, copper, platinum, palladium, and zinc, and an alkali metal are supported on a support. The binary functional catalyst is usually in powder or granular form.

[0047] <Indium, copper, platinum, palladium, zinc> Indium (In) is an element in Group 13, Period 5 of the periodic table. Copper (Cu) is an element in Group 11, Period 4 of the periodic table. Platinum (Pt) is an element in Group 10, Period 6 of the periodic table. Palladium (Pd) is an element in Group 10, Period 5 of the periodic table. Zinc (Zn) is an element in Group 12, Period 4 of the periodic table. At least one element selected from the group consisting of indium, copper, platinum, palladium, and zinc is supported on a carrier together with an alkali metal. At least one element selected from the group consisting of indium, copper, platinum, palladium, and zinc acts as an active site together with the alkali metal, and can exhibit the above-mentioned storage function and reduction function in the reverse water-gas shift reaction. Moreover, even when the gas to be treated contains not only carbon dioxide but also carbon monoxide, the above-mentioned storage function and reduction function are excellent, so more carbon monoxide can be produced from carbon dioxide. Of indium, copper, platinum, palladium, and zinc, indium and copper are preferred, with indium being more preferred. The inclusion of indium and copper in the composite reduces the yield of by-products such as methane, thereby relatively increasing the carbon monoxide yield, and consequently enhancing the reducing function. These elements can be used individually, or as a mixture of two or more.

[0048] The content of at least one selected from the group consisting of indium, copper, platinum, palladium, and zinc in the binary-function catalyst is preferably 1 to 70% by mass, more preferably 1 to 30% by mass, even more preferably 2 to 25% by mass, even more preferably 5 to 25% by mass, and particularly preferably 10 to 20% by mass. By setting the content of at least one selected from the group consisting of indium, copper, platinum, palladium, and zinc within the above ranges, the storage function and the reduction function are further enhanced.

[0049] <Alkali metals> Alkali metals are elements of Group 1 in the periodic table. Alkali metals are supported on a carrier together with at least one selected from the group consisting of indium, copper, platinum, palladium, and zinc. The alkali metals, together with at least one selected from the group consisting of indium, copper, platinum, palladium, and zinc, act as active sites and can exert the above-mentioned storage and reduction functions in the reverse water-gas shift reaction. Moreover, even when the off-gas contains carbon monoxide in addition to carbon dioxide, the above-mentioned storage and reduction functions are excellent, allowing more carbon monoxide to be produced from carbon dioxide.

[0050] The alkali metal is not particularly limited, as long as it can serve as an active site for exhibiting the above-mentioned storage function and reduction function. Examples of alkali metals include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr), of which sodium, potassium, rubidium, and cesium are preferred. By selecting the above elements as alkali metals, the above-mentioned storage function and reduction function can be further enhanced. Alkali metals can be used individually, or as a mixture of two or more.

[0051] The alkali metal content in the dual-function catalyst is preferably 1 to 70% by mass, more preferably 1 to 40% by mass, even more preferably 3 to 30% by mass, even more preferably 5 to 25% by mass, and particularly preferably 10 to 20% by mass. By setting the alkali metal content within the above ranges, the storage function and the reduction function can be further enhanced. The content of at least one selected from the group consisting of indium, copper, platinum, palladium, and zinc, and the alkali metal content can be appropriately set within a range where the total content, including the content of the carrier and any other components, does not exceed 100% by mass.

[0052] <Mass ratio of at least one selected from the group consisting of indium, copper, platinum, palladium, and zinc to an alkali metal> The mass ratio of at least one selected from the group consisting of indium, copper, platinum, palladium, and zinc to an alkali metal is preferably set to 1:0.2 to 1:20, more preferably set to 1:0.5 to 1:20, and even more preferably set to 1:5 to 1:20. By setting the mass ratio of at least one selected from the group consisting of indium, copper, platinum, palladium, and zinc to an alkali metal within the above range, the above occlusion function and the above reduction function can be further enhanced.

[0053] <Support> The support is one that supports at least one selected from the group consisting of indium, copper, platinum, palladium, and zinc having active sites and an alkali metal, and a composite is formed by their being supported on the support. Examples of the support include metal oxides. In this case, the dual-functional catalyst will include a composite oxide of at least one selected from the group consisting of indium, copper, platinum, palladium, and zinc, an alkali metal, and a metal oxide. When the content of at least one selected from the group consisting of indium, copper, platinum, palladium, and zinc in the dual-functional catalyst is X (mass %), the alkali metal is A, the content of the alkali metal A in the dual-functional catalyst is Y (mass %), the metal in the metal oxide is B, its molar number is m, and the molar number of oxygen is n, the dual-functional catalyst is In(X)A(Y) / B m O n , Cu(X)A(Y) / B m O n , Pt(X)A(Y) / B m O n , Pd(X)A(Y) / B m O n , Zn(X)A(Y) / B m O n , In(X1)Cu(X2)A(Y) / B m O nIt can be expressed by structural formulas such as the following. Note that " / " indicates that the element on the left is supported in the compound on the right. Also, if multiple elements are selected from indium, copper, platinum, palladium, and zinc, "X" is the total content, and the content of each element can be expressed as "X1", "X2", "X3", and "X4" depending on the number of elements selected (1 to 4). In such metal oxides, as described above, the content X of at least one element selected from the group consisting of indium, copper, platinum, palladium, and zinc, the content Y of alkali metals, and the mass ratio (X:Y) of at least one element selected from indium, copper, platinum, palladium, and zinc to alkali metals can be set as described above.

[0054] Preferred metal oxides for the support are zirconium oxide, aluminum oxide, titanium oxide, and magnesium oxide. Zirconium oxide is ZrO2, which corresponds to the case where B is Zr, m is 1, and n is 2 in the above structural formula. Aluminum oxide (Al2O3) corresponds to the case where B is Al, m is 2, and n is 3 in the above structural formula. Titanium oxide (TiO2) corresponds to the case where B is Ti, m is 1, and n is 2 in the above structural formula. Magnesium oxide (MgO) corresponds to the case where B is Mg, m is 1, and n is 1 in the above structural formula. By selecting the above metal oxides as the support, at least one selected from indium, copper, platinum, palladium, and zinc, which have active sites, and an alkali metal can be more reliably supported, forming a stronger composite, and thus the above storage function and the above reduction function can be more reliably exhibited. The support can be used individually, or as a mixture of two or more types.

[0055] As shown in Figure 1(a), the first switching valve 33 is configured to switch between a state in which the first port 33a and the second port 33b, and the third port 33c and the fourth port 33d are connected (hereinafter referred to as the "first switching state") and a state in which the first port 33a and the fourth port 33d, and the second port 33b and the third port 33c are connected (hereinafter referred to as the "second switching state"), as shown in Figure 1(b).

[0056] As shown in Figure 1(a), the second switching valve 34 is configured to switch between a state in which the first port 34a and the second port 34b, and the third port 34c and the fourth port 34d are connected (hereinafter referred to as the "first switching state") and a state in which the first port 34a and the fourth port 34d, and the second port 34b and the third port 34c are connected (hereinafter referred to as the "second switching state"), as shown in Figure 1(b).

[0057] In the first exchange valve 33, the first port 33a is connected to the gas outlet 2b of the oxidation-reduction reactor 2 via the gas line 41. The second port 33b is connected to the gas inlet 31a of the first reactor 31 via the gas line 42. The third port 33c is connected to the hydrogen storage and supply device 20 via the gas line 43. The fourth port 33d is connected to the gas inlet 32a of the second reactor 32 via the gas line 44. Note that the gas line 41 corresponds to the "off-gas line" of the present invention.

[0058] Here, although a detailed explanation with illustrations is omitted, the hydrogen storage and supply device 20 may include, for example, a device equipped with a hydrogen gas tank, a booster, and a pressure reducing valve, which stores hydrogen gas produced by electrolyzing water using electricity from a power generation facility that generates electricity using the heat of combustion exhaust gas from a waste incineration treatment facility, and / or from a power generation facility that generates electricity using renewable energy, in a pressurized state in the hydrogen gas tank via a booster, and then supplies the compressed hydrogen gas stored in the hydrogen gas tank to a hydrogen demand site after being reduced to a predetermined pressure by a pressure reducing valve. Other examples of hydrogen storage and supply devices 20 include a configuration in which a hydrogen storage alloy tank absorbs and retains hydrogen gas. The hydrogen storage and supply device 20 may also take the form of a device in which the components (hydrogen gas tank, booster, pressure reducing valve, etc.) are housed in a container and packaged so that it can be transported by vehicle or the like.

[0059] In the second switching valve 34, the first port 34a is connected to the carbon-containing gas line 10 via the gas line 51. The second port 34b is connected to the gas outlet 31b of the first reactor 31 via the gas line 52. The third port 34c is connected to the carbon-containing gas line 10 via the gas line 53. The fourth port 34d is connected to the gas outlet 32b of the second reactor 32 via the gas line 54.

[0060] In the carbon recycling facility 1A configured as described above, a carbon recycling method is carried out that includes the following steps: a carbon-containing gas supply step, a redox reaction step (solid carbonization step), a first off-gas supply step, a carbon dioxide storage step, a reducing gas supply step, a carbon monoxide generation step, and a second off-gas supply step. Of these steps, the essential steps in the carbon recycling method of the present invention are the redox reaction step (solid carbonization step), the carbon dioxide storage step, and the carbon monoxide generation step, while the other steps can be carried out as needed.

[0061] <Carbon-containing gas supply process> The carbon-containing gas is supplied to the oxidation-reduction reactor 2 via the carbon-containing gas line 10.

[0062] <Redox reaction process (solid carbonization process)> The redox reaction apparatus 2 uses a carbon-containing gas supplied via the carbon-containing gas line 10 as a raw material gas and generates solid carbon through a redox reaction (Booduar reaction). The redox reaction process corresponds to the "carbon resource utilization process" of the present invention (the same applies to the carbon recycling equipment 1F to H of the other embodiments 1 to 3 described later).

[0063] <First off-gas supply process> The gas containing carbon dioxide, a by-product of the Booduor reaction, is introduced from the redox reactor 2 as the first off-gas to the catalytic reduction reactor 3 via the gas line 41.

[0064] <Carbon dioxide storage process> When the first off-gas valve 33 is in the first off-gas state shown in Figure 1(a), the first off-gas is introduced into the first reactor 31 from the gas line 41 via the first port 33a and the second port 33b of the first off-gas valve 33 and the gas line 42. As a result, the carbon dioxide contained in the first off-gas is absorbed into the catalyst of the first reactor 31.

[0065] When the second switching valve 34 is in the first switching state shown in Figure 1(a), the exhaust gas discharged from the gas outlet 31b of the first reactor 31 is joined to the carbon-containing gas flowing through the carbon-containing gas line 10 via the gas line 52, the second port 34b and the first port 34a of the second switching valve 34, and the gas line 51.

[0066] <Reducing gas supply process> When the first-round exchange valve 33 is in the first-round exchange state shown in Figure 1(a), reducing gas (gas mainly composed of hydrogen) from the hydrogen storage and supply device 20 is introduced into the second reactor 32 via the gas line 43, through the third port 33c and fourth port 33d of the first-round exchange valve 33, and the gas line 44. As a result, the hydrogen contained in the reducing gas comes into contact with the catalyst in the second reactor 32.

[0067] When the second switching valve 34 is in the first switching state shown in Figure 1(a), the exhaust gas discharged from the gas outlet 32b of the second reactor 32 is joined to the carbon-containing gas flowing through the carbon-containing gas line 10 via the gas line 54, the fourth port 34d and the third port 34c of the second switching valve 34, and the gas line 53.

[0068] After a predetermined time has elapsed (for example, after 30 seconds), the first switching valve 33 and the second switching valve 34 are switched from the first switching state shown in Figure 1(a) to the second switching state shown in Figure 1(b).

[0069] <Carbon dioxide storage process> When the first off-gas valve 33 is in the second switching state shown in Figure 1(b), the first off-gas is introduced into the second reactor 32 from the gas line 41 via the first port 33a and the fourth port 33d of the first off-gas valve 33 and the gas line 44. As a result, the carbon dioxide contained in the first off-gas is absorbed into the catalyst of the second reactor 32.

[0070] When the second switching valve 34 is in the second switching state shown in Figure 1(b), the exhaust gas discharged from the gas outlet 32b of the second reactor 32 is joined to the carbon-containing gas flowing through the carbon-containing gas line 10 via the gas line 54, the fourth port 34d and the first port 34a of the second switching valve 34, and the gas line 51.

[0071] <Reducing gas supply process> When the first-row exchange valve 33 is in the second switching state shown in Figure 1(b), reducing gas (gas mainly composed of hydrogen) from the hydrogen storage and supply device 20 is introduced into the first reactor 31 via the gas line 43, through the third port 33c and second port 33b of the first-row exchange valve 33, and the gas line 42. As a result, the hydrogen contained in the reducing gas comes into contact with the catalyst in the first reactor 31.

[0072] When the second switching valve 34 is in the second switching state shown in Figure 1(b), the exhaust gas discharged from the gas outlet 31b of the first reactor 31 is joined to the carbon-containing gas flowing through the carbon-containing gas line 10 via the gas line 52, the second port 34b and third port 34c of the second switching valve 34, and the gas line 53.

[0073] After a predetermined time has elapsed (for example, after 30 seconds), the first switching valve 33 and the second switching valve 34 are switched from the second switching state shown in Figure 1(b) to the first switching state shown in Figure 1(a).

[0074] <Carbon monoxide generation process> Thus, the first switching valve 33 and the second switching valve 34 are repeatedly switched alternately between the first switching state shown in Figure 1(a) and the second switching state shown in Figure 1(b) at predetermined intervals. In this way, in the first reactor 31, the carbon dioxide storage step, in which carbon dioxide contained in the off-gas is absorbed into the catalyst, and the carbon monoxide generation step, in which carbon monoxide is produced by a reduction reaction when hydrogen contained in the reducing gas comes into contact with the catalyst that has absorbed carbon dioxide in the carbon dioxide storage step, are repeated alternately. At the same time, in the second reactor 32, the carbon monoxide generation step, in which carbon monoxide is produced by a reduction reaction when hydrogen contained in the reducing gas comes into contact with the catalyst that has absorbed carbon dioxide in the carbon dioxide storage step, and the carbon dioxide storage step, in which carbon dioxide contained in the off-gas is absorbed into the catalyst, are repeated alternately. In this way, the carbon dioxide storage step and the carbon monoxide generation step are repeated alternately in the first reactor 31, and at the same time, the carbon monoxide generation step and the carbon dioxide storage step are repeated alternately in the second reactor 32. In other words, in the first reactor 31 and the second reactor 32, the carbon dioxide storage process and the carbon monoxide generation process are repeated alternately. As a result, in the catalytic reduction device 3, the carbon dioxide storage process is carried out continuously while the carbon monoxide generation process is carried out continuously, enabling the continuous and efficient generation of carbon monoxide.

[0075] <Second off-gas supply process> The gas containing carbon monoxide generated in the catalytic reduction device 3 is then introduced into the redox reactor 2 as a second off-gas, flowing through the gas line 53 to the carbon-containing gas line 10. In this way, the solid carbonization process is carried out in the redox reactor 2 using the second off-gas containing carbon monoxide generated during the carbon dioxide storage process and the carbon monoxide generation process.

[0076] According to the carbon recycling equipment 1A of the first embodiment, even if the first off-gas from the redox reactor 2 contains carbon dioxide produced as a by-product by the Booduor reaction, the catalyst in the catalytic reduction device 3 generates carbon monoxide from the carbon dioxide and reducing gas, and the second off-gas containing the generated carbon monoxide is used as a raw material gas for the Booduor reaction in the redox reactor 2, thereby improving the efficiency of solid carbon production.

[0077] In the carbon recycling equipment 1A of the first embodiment, when the second switching valve 34 is in the first switching state shown in Figure 1(a), the exhaust gas discharged from the gas outlet 31b of the first reactor 31 contains carbon dioxide that was not absorbed by the catalyst of the first reactor 31. Also, when the second switching valve 34 is in the second switching state shown in Figure 1(b), the exhaust gas discharged from the gas outlet 32b of the second reactor 32 contains carbon dioxide that was not absorbed by the catalyst of the second reactor 32. In the carbon recycling equipment 1A of the first embodiment, the exhaust gas containing carbon dioxide that was not absorbed by the catalysts of each reactor 31 and 32 is merged with the carbon-containing gas flowing through the carbon-containing gas line 10 via the gas line 51 and recycled again as a raw material for solid carbon, thereby improving the yield of solid carbonization and reducing the amount of carbon dioxide that is wasted without being converted into solid carbon.

[0078] [Second Embodiment] Figure 2 is a block diagram illustrating the schematic configuration of carbon recycling equipment 1B according to the second embodiment of the present invention. Figure 2(a) shows the case when the switching valves 33 and 34 are in the first switching state, and Figure 2(b) shows the case when the switching valves 33 and 34 are in the second switching state. In the second embodiment, parts that are the same as or similar to those in carbon recycling equipment 1A of the first embodiment are denoted by the same reference numerals in the figures, and detailed explanations are omitted. Hereafter, the explanation will focus on parts specific to the second embodiment (the same applies to the third to fifth embodiments and other embodiments 1 to 3 described later).

[0079] If the concentration of water in the first off-gas introduced from the redox reactor 2 to the catalytic reduction reactor 3 via the gas line 41 is high, the water may be adsorbed onto the catalysts in reactors 31 and 32, potentially inhibiting the reduction reaction of carbon dioxide. Therefore, in the carbon recycling facility 1B of the second embodiment, a water removal device 4 is installed in the gas line 41 to remove water from the first off-gas.

[0080] Here, the moisture removal device 4 is not particularly limited as long as it can be configured to remove moisture from the first off-gas. For example, it can be configured to adsorb moisture from the first off-gas by passing the first off-gas through an adsorption section filled with an adsorbent that adsorbs moisture, or it can be configured to remove moisture from the first off-gas by passing the first off-gas through a moisture removal filter.

[0081] According to the carbon recycling equipment 1B of the second embodiment, since moisture in the first off-gas is removed in advance by the moisture removal device 4 interposed in the gas line 41, it is possible to prevent the reduction reaction of carbon dioxide by the catalyst in reactors 31 and 32 from being inhibited by water.

[0082] [Third Embodiment] Figure 3 is a block diagram illustrating the schematic configuration of carbon recycling equipment 1C according to the third embodiment of the present invention. Figure 3(a) shows the case when the switching valves 33 and 34 are in the first switching state, and Figure 3(b) shows the case when the switching valves 33 and 34 are in the second switching state.

[0083] In the carbon recycling equipment 1C of the third embodiment, a hydrogen separation device 5 for separating hydrogen from the first off-gas is interposed between the moisture removal device 4 and the first exchange valve 33 in the gas line 41, as in the carbon recycling equipment 1B of the second embodiment.

[0084] Here, the hydrogen separation device 5 is not particularly limited, as long as it is capable of separating hydrogen from the first off-gas. For example, it can be a device that separates hydrogen from the first off-gas using a pressure swing adsorption method, a device that separates hydrogen from the first off-gas using a hydrogen separation metal that selectively permeates hydrogen, such as palladium or a palladium alloy, or a device that separates hydrogen from the first off-gas using a membrane separation module with a hydrogen separation membrane that selectively permeates hydrogen (for example, an organic membrane made from an organic polymer compound, or an inorganic membrane made by sintering an inorganic material). In this way, in the carbon recycling facility 1C, unreacted hydrogen contained in the first off-gas introduced from the oxidation-reduction reactor 2 to the catalytic reduction device 3 via the gas line 41 can be separated and recovered by the hydrogen separation device 5.

[0085] Furthermore, in the carbon recycling equipment 1C of the third embodiment, the hydrogen separator 5 and the carbon-containing gas line 10 are connected via the gas line 61, and the hydrogen separated by the hydrogen separator 5 is introduced into the oxidation-reduction reactor 2 via the gas line 61 and the carbon-containing gas line 10.

[0086] According to the carbon recycling equipment 1C of the third embodiment, the hydrogen separated in the hydrogen separator 5 is introduced into the redox reactor 2 via the gas line 61 and the carbon-containing gas line 10. As a result, the Boodor reaction in the redox reactor 2 is carried out in a reducing atmosphere, which can accelerate the Boodor reaction.

[0087] [Fourth Embodiment] Figure 4 is a block diagram illustrating the schematic configuration of carbon recycling equipment 1D according to the fourth embodiment of the present invention. Figure 4(a) shows the case when the switching valves 33 and 34 are in the first switching state, and Figure 4(b) shows the case when the switching valves 33 and 34 are in the second switching state.

[0088] In the carbon recycling facility 1D of the fourth embodiment, the hydrogen separator 5 and the gas line 43 are connected via the gas line 62, and the hydrogen separated by the hydrogen separator 5 is combined with the gas flowing through the gas line 43 via the gas line 62 and used as a reducing gas.

[0089] According to the carbon recycling equipment 1D of the fourth embodiment, since the hydrogen separated in the hydrogen separation device 5 is used as a reducing gas introduced into the catalytic reduction device 3, unreacted hydrogen contained in the first off-gas can be effectively utilized.

[0090] [Fifth Embodiment] Figure 5 is a block diagram illustrating the schematic configuration of carbon recycling equipment 1E according to the fifth embodiment of the present invention. Figure 5(a) shows the case when the switching valves 33 and 34 are in the first switching state, and Figure 5(b) shows the case when the switching valves 33 and 34 are in the second switching state.

[0091] In the fifth embodiment of the carbon recycling equipment 1E, a first heat transfer medium circulation path 71 is provided between the first reactor 31 and the oxidation-reduction reactor 2, and a second heat transfer medium circulation path 72 is provided between the second reactor 32 and the oxidation-reduction reactor 2, and the equipment is configured to use the reaction heat in the oxidation-reduction reactor 2 to maintain the temperature necessary for the reduction reaction in the catalytic reduction device 3.

[0092] According to the carbon recycling equipment 1E of the fifth embodiment, by utilizing the reaction heat in the oxidation-reduction reactor 2, the thermal energy required to maintain the temperature necessary for the reduction reaction in the catalytic reduction device 3 can be reduced, thereby lowering energy costs.

[0093] Although the carbon recycling equipment and carbon recycling method of the present invention have been described above based on several embodiments, the present invention is not limited to the configurations described in the above embodiments, and the configuration can be modified as appropriate without departing from the spirit of the invention, such as by appropriately combining the configurations described in each embodiment.

[0094] (Another Embodiment 1) Figure 6 is a block diagram showing the schematic configuration of carbon recycling equipment 1F of another embodiment 1. In each of the above embodiments, the carbon dioxide storage process and the carbon monoxide generation process are repeated alternately in the first reactor 31 and the second reactor 32, so that in the catalytic reduction device 3, the carbon dioxide storage process is carried out continuously and the carbon monoxide generation process is carried out continuously, thereby continuously generating carbon monoxide. However, the invention is not limited to this. As shown in Figure 6, in carbon recycling equipment 1F, as a representative example, instead of the first reactor 31 and the second reactor 32 in carbon recycling equipment 1A of the first embodiment, a single reactor 30 with a configuration similar to these reactors 31 and 32 may be used to generate carbon monoxide by batch processing. It goes without saying that the carbon recycling equipment 1B to 1E of the second to fifth embodiments can also adopt a configuration using a single reactor 30 in the same way.

[0095] <Catalytic Reduction Device> In the carbon recycling facility 1F shown in Figure 6, the catalytic reduction device 3 is equipped with a reactor 30, a first switching valve 33, and a second switching valve 34.

[0096] Reactor 30 has a gas inlet 30a and a gas outlet 30b, and, like the first reactor 31 and the second reactor 32, is a reactor filled with a catalyst that can absorb and reduce carbon dioxide. The catalyst used to fill reactor 30 is the same catalyst used in the first reactor 31 and the second reactor 32.

[0097] The first switching valve 33 is configured to switch between a state in which the first port 33a and the second port 33b are connected (hereinafter referred to as the "first switching state"), as shown in Figure 6(a), and a state in which the second port 33b and the third port 33c are connected (hereinafter referred to as the "second switching state"), as shown in Figure 6(b).

[0098] The second switching valve 34 is configured to switch between a state in which the first port 34a and the second port 34b are connected (hereinafter referred to as the "first switching state") as shown in Figure 6(a), and a state in which the second port 34b and the third port 34c are connected (hereinafter referred to as the "second switching state") as shown in Figure 6(b).

[0099] In the first exchange valve 33, the first port 33a is connected to the gas outlet 2b of the oxidation-reduction reactor 2 via the gas line 41. The second port 33b is connected to the gas inlet 30a of the reactor 30 via the gas line 42. The third port 33c is connected to the hydrogen storage and supply device 20 via the gas line 43.

[0100] In the second switching valve 34, the first port 34a is connected to the carbon-containing gas line 10 via the gas line 51. The second port 34b is connected to the gas outlet 30b of the reactor 30 via the gas line 52. The third port 34c is connected to the carbon-containing gas line 10 via the gas line 53.

[0101] In the carbon recycling facility 1F of the alternative embodiment 1, which is configured as described above, the following processes are carried out: a carbon-containing gas supply process, a redox reaction process (solid carbonization process), a first off-gas supply process, a carbon dioxide storage process, a reducing gas supply process, a carbon monoxide generation process, and a second off-gas supply process.

[0102] <Carbon-containing gas supply process> The carbon-containing gas is supplied to the oxidation-reduction reactor 2 via the carbon-containing gas line 10.

[0103] <Redox reaction process (solid carbonization process)> The redox reaction apparatus 2 uses a carbon-containing gas supplied via the carbon-containing gas line 10 as a raw material gas to produce solid carbon through a redox reaction (Booduar reaction).

[0104] <First off-gas supply process> The gas containing carbon dioxide, a by-product of the Booduor reaction, is introduced from the redox reactor 2 as the first off-gas to the catalytic reduction reactor 3 via the gas line 41.

[0105] <Carbon dioxide storage process> When the first off-gas valve 33 is in the first off-gas state shown in Figure 6(a), the first off-gas is introduced into the reactor 30 from the gas line 41 via the first port 33a and the second port 33b of the first off-gas valve 33 and the gas line 42. As a result, the carbon dioxide contained in the first off-gas is absorbed into the catalyst in the reactor 30.

[0106] When the second switching valve 34 is in the first switching state shown in Figure 6(a), the exhaust gas discharged from the gas outlet 30b of the reactor 30 is joined to the carbon-containing gas flowing through the carbon-containing gas line 10 via the gas line 52, the second port 34b and the first port 34a of the second switching valve 34, and the gas line 51.

[0107] After a predetermined time has elapsed (for example, after 30 seconds), the first switching valve 33 and the second switching valve 34 are switched from the first switching state shown in Figure 6(a) to the second switching state shown in Figure 6(b).

[0108] <Reducing gas supply process> When the first-instance valve 33 is in the second switching state shown in Figure 6(b), reducing gas (gas mainly composed of hydrogen) from the hydrogen storage and supply device 20 is introduced into the reactor 30 via the gas line 43, the third port 33c and the second port 33b of the first-instance valve 33, and the gas line 42. As a result, the hydrogen contained in the reducing gas comes into contact with the catalyst in the reactor 30.

[0109] When the second switching valve 34 is in the second switching state shown in Figure 6(b), the exhaust gas discharged from the gas outlet 30b of the reactor 30 is joined to the carbon-containing gas flowing through the carbon-containing gas line 10 via the gas line 52, the second port 34b and third port 34c of the second switching valve 34, and the gas line 53.

[0110] After a predetermined time has elapsed (for example, after 30 seconds), the first switching valve 33 and the second switching valve 34 are switched from the second switching state shown in Figure 6(b) to the first switching state shown in Figure 6(a).

[0111] <Carbon monoxide generation process> In this way, the first switching valve 33 and the second switching valve 34 are repeatedly switched alternately between the first switching state shown in Figure 6(a) and the second switching state shown in Figure 6(b) at predetermined intervals. As a result, in the reactor 30, the carbon dioxide storage step, in which carbon dioxide contained in the off-gas is absorbed by the catalyst, and the carbon monoxide generation step, in which carbon monoxide is produced by a reduction reaction when hydrogen contained in the reducing gas comes into contact with the catalyst that has absorbed carbon dioxide, are repeated alternately at predetermined intervals. This allows the catalytic reduction device 3 to generate carbon monoxide in a batch process.

[0112] <Second off-gas supply process> The gas containing carbon monoxide generated in the catalytic reduction device 3 is then introduced into the redox reactor 2 as a second off-gas, flowing through the gas line 53 to the carbon-containing gas line 10. In this way, the solid carbonization process is carried out in the redox reactor 2 using the second off-gas containing carbon monoxide generated during the carbon dioxide storage process and the carbon monoxide generation process.

[0113] In the carbon recycling facility 1F of the alternative embodiment 1, carbon monoxide is generated from carbon dioxide and reducing gases contained in the first off-gas by the action of the catalyst in the catalytic reduction device 3, and the second off-gas containing the generated carbon monoxide is used as a raw material gas for the Booduor reaction in the redox reaction device 2, thereby improving the efficiency of solid carbon generation.

[0114] (Another Embodiment 2) Figure 7 is a block diagram showing the schematic configuration of carbon recycling equipment 1G of another embodiment 2. Figure 7(a) shows the case when the switching valves 33 and 34 are in the first switching state, and Figure 7(b) shows the case when the switching valves 33 and 34 are in the second switching state. In the carbon recycling equipment 1C of the third embodiment (see Figure 3) described above, an example was shown in which a hydrogen separation device 5 for separating hydrogen in the first off-gas is interposed between the moisture removal device 4 in the gas line 41 and the first switching valve 33, but the invention is not limited to this, and a configuration such as carbon recycling equipment 1G shown in Figure 7 may be adopted.

[0115] In carbon recycling facility 1G, a hydrogen separator 5 is installed in the gas line 51 through which the gas remaining after carbon dioxide has been absorbed by the catalysts in reactors 31 and 32 (which may contain carbon dioxide that was not absorbed by the catalysts) flows, in order to separate hydrogen from the gas. Furthermore, in carbon recycling facility 1G, the hydrogen separator 5 and the gas line 43 are connected via a gas line 63, and the hydrogen separated by the hydrogen separator 5 is combined with the gas flowing through the gas line 43 via the gas line 63 and used as a reducing gas.

[0116] As the hydrogen separation device 5, for example, a configuration that separates hydrogen from the gas using a hydrogen separation membrane is employed. Depending on the hydrogen separation membrane, the separation performance of carbon monoxide and hydrogen may be high, but the separation performance of carbon dioxide and hydrogen may be low. Even in such cases, in the carbon recycling facility 1G, the gas after carbon dioxide has been reduced by carbon dioxide storage by the catalysts in reactors 31 and 32 is introduced into the hydrogen separation device 5, so unreacted hydrogen contained in the gas after carbon dioxide has been stored by the catalysts in reactors 31 and 32 can be efficiently recovered.

[0117] Furthermore, in carbon recycling facility 1G, the hydrogen separated in hydrogen separator 5 is used as a reducing gas introduced into reactors 31 and 32, so that unreacted hydrogen contained in the gas after carbon dioxide has been absorbed by the catalysts in reactors 31 and 32 can be effectively utilized.

[0118] (Another embodiment 3) Figure 8 is a block diagram illustrating the schematic configuration of carbon recycling equipment 1H according to another embodiment 3. Figure 8(a) shows the case where the switching valves 33 and 34 are in the first switching state, and Figure 8(b) shows the case where the switching valves 33 and 34 are in the second switching state. In each of the above embodiments, an example was shown in which the gas after carbon dioxide has been absorbed by the catalysts in reactors 31 and 32 is merged with the carbon-containing gas flowing through the carbon-containing gas line 10 via the gas line 51, but the invention is not limited to this, and a configuration such as carbon recycling equipment 1H shown in Figure 8 may be adopted.

[0119] In carbon recycling facility 1H, the first port 34a of the second switching valve 34 and the gas line 43 are connected via the gas line 55. The gas after carbon dioxide has been absorbed by the catalysts in reactors 31 and 32 is introduced into reactors 31 and 32 together with the reducing gas flowing through the gas line 43, thereby generating carbon monoxide through the action of the catalysts. In carbon recycling facility 1H with this configuration, the unreacted hydrogen contained in the gas after carbon dioxide has been absorbed by the catalysts in reactors 31 and 32 is used as the reducing gas introduced into reactors 32 and 31. Therefore, unlike carbon recycling facilities 1D and 1G, which use unreacted hydrogen separated by the hydrogen separation device 5 as the reducing gas, unreacted hydrogen can be effectively utilized with a simple configuration. [Industrial applicability]

[0120] The carbon recycling equipment and carbon recycling method of the present invention can be used, for example, in applications to produce chemical products such as solid carbon or hydrocarbon fuels such as methane from carbon dioxide contained in exhaust gas generated by the combustion of fossil fuels in thermal power plants, steel mills, petroleum refineries, etc.; carbon dioxide contained in exhaust gas generated by the combustion of off-gas in hydrogen production facilities; carbon dioxide contained in exhaust gas generated by the combustion of waste in general waste incineration facilities; and carbon dioxide contained in exhaust gas generated by the combustion of biomass fuel in biomass power generation facilities.

[0121] 1A-1H Carbon Recycling Facility 2. Redox reaction apparatus (carbon resource recovery apparatus) 3. Catalytic Reduction Device 4 Moisture removal device 5. Hydrogen separation device 41 Gas lines (off-gas lines) 43. Gas lines (reducing gas lines)

Claims

1. A carbon resource conversion device that converts carbon-containing gases into resources through a carbon resource conversion reaction, A catalytic reduction apparatus having a catalyst capable of absorbing and reducing carbon dioxide, An off-gas line for introducing off-gas containing carbon dioxide from the carbon resource recovery device to the catalytic reduction device, A reducing gas line for introducing reducing gas to the catalyst reduction device, Equipped with, A carbon recycling facility configured to introduce the off-gas and the reducing gas into the catalytic reduction device, thereby introducing the gas containing carbon monoxide produced by the action of the catalyst from the catalytic reduction device to the carbon resource recovery device.

2. The carbon recycling equipment according to claim 1, wherein the carbon-containing gas comprises carbon dioxide and / or carbon monoxide.

3. The carbon recycling equipment according to claim 1 or 2, wherein the reducing gas comprises hydrogen.

4. The carbon recycling facility according to claim 1 or 2, wherein a moisture removal device for removing moisture from the off-gas is interposed in the off-gas line.

5. The carbon recycling facility according to claim 1 or 2, wherein a hydrogen separation device for separating hydrogen from the off-gas is interposed in the off-gas line.

6. The carbon recycling equipment according to claim 5, configured to introduce the hydrogen separated by the hydrogen separation device into the carbon resource recovery device.

7. The carbon recycling equipment according to claim 5, configured to use the hydrogen separated by the hydrogen separation device as the reducing gas.

8. The carbon recycling equipment according to claim 1 or 2, wherein a hydrogen separation device for separating hydrogen from the gas is interposed in the gas line through which the gas, after carbon dioxide has been absorbed by the catalyst, flows.

9. The carbon recycling equipment according to claim 8, configured to use the hydrogen separated by the hydrogen separation device as the reducing gas.

10. The carbon recycling equipment according to claim 1 or 2, wherein the gas after carbon dioxide has been absorbed by the catalyst is introduced into the catalytic reduction device, thereby generating carbon monoxide through the action of the catalyst.

11. The carbon recycling equipment according to claim 1 or 2, configured to use the reaction heat in the carbon resource recovery device to maintain the temperature necessary for the reduction reaction in the catalytic reduction device.

12. The carbon recycling equipment according to claim 1 or 2, wherein the catalyst is a dual-function catalyst comprising a composite of at least one selected from the group consisting of indium, copper, platinum, palladium, and zinc, an alkali metal, and a support.

13. The carbon recycling equipment according to claim 1 or 2, wherein the carbon resource conversion reaction is an oxidation-reduction reaction.

14. A carbon resource conversion process that converts carbon-containing gases into resources through a carbon resource conversion reaction, A carbon dioxide storage step involves contacting a catalyst with an off-gas containing carbon dioxide to cause the catalyst to absorb carbon dioxide, A carbon monoxide generation step involves contacting a reducing gas with the catalyst that has absorbed carbon dioxide to generate carbon monoxide, It includes, A carbon recycling method that uses a gas containing carbon monoxide generated in connection with the carbon dioxide storage step and the carbon monoxide generation step to perform the carbon resource conversion step.

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