Carbon dioxide conversion device

Abstract

To provide a carbon dioxide (CO2) conversion apparatus capable of facilitating the effective use of CO2 and reducing the discharge of CO2 into the atmosphere.SOLUTION: A CO2 conversion apparatus 1 of an embodiment comprises: an electrolysis part 3 including a cathode chamber 6 and an anode chamber 7 for reducing CO2 to generate CO; an organic substance synthesis part 4 for synthesizing an organic substance from a material gas containing a CO-containing gas supplied from the cathode chamber 6; and an oxygen permeable membrane type partial oxidation part 5 including a partial oxidation chamber 10 to which synthetic residual gas of the organic substance discharged from the organic substance synthesis part 4 is supplied, an oxygen removal chamber 11 to which an oxygen-carbon dioxide containing gas discharged from the anode chamber 7 is supplied, and an oxygen permeable membrane 12 arranged between the partial oxidation chamber 10 and the oxygen removal chamber 11.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] Embodiments of the present invention relate to a carbon dioxide conversion device. [Background technology]

[0002] Carbon dioxide (CO2), generated by burning fossil fuels such as natural gas, coal, and oil, is considered a major cause of global warming due to the greenhouse effect, and there is a demand to reduce the use of fossil fuels. In addition to removing CO2 from exhaust gases emitted from CO2 sources and suppressing its release into the atmosphere, chemical synthesis using CO2 removed from exhaust gases is being carried out. As part of this, technology is being developed to reduce CO2 to produce carbon monoxide (CO), and to synthesize organic matter from the produced CO and hydrogen (H2). A portion of the purge gas after CO generation is supplied to a CO2 electrolysis device, and the remainder is detoxified by combustion in air and released into the atmosphere. The CO2 supplied to purge the oxygen generated from the CO2 electrolysis device, and the CO2 released from the combustion device, are released into the atmosphere without being effectively utilized from the CO2 supplied to the CO2 electrolysis device. For this reason, there is a need for a carbon dioxide conversion device that effectively utilizes the supplied CO2 and reduces the release of CO2 into the atmosphere. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] International Publication No. 2014 / 154253 [Patent Document 2] Japanese Patent Publication No. 2021-055124 [Patent Document 3] Japanese Patent Publication No. 2019-218578 [Patent Document 4] Japanese Patent Publication No. 2016-124759 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] The problem to be solved by the present invention is to provide a carbon dioxide conversion device that promotes the effective utilization of CO2 and enables the reduction of the emission of CO2 into the atmosphere.

Means for Solving the Problem

[0005] The carbon dioxide conversion device according to the embodiment includes a carbon dioxide recovery unit that recovers carbon dioxide from a carbon dioxide-containing gas, a cathode chamber to which the carbon dioxide recovered by the carbon dioxide recovery unit is supplied and that reduces the carbon dioxide to convert it into carbon monoxide, an anode chamber that oxidizes an oxide to generate an oxide, a carbon dioxide electrolysis unit including the anode chamber and the cathode chamber, an organic substance synthesis unit to which a carbon monoxide-containing gas is supplied from the cathode chamber of the carbon dioxide electrolysis unit and that synthesizes an organic substance from a raw material gas containing the carbon monoxide-containing gas, a partial oxidation chamber to which the synthesis residual gas of the organic substance discharged from the organic substance synthesis unit is supplied, an oxygen removal chamber to which an oxygen-carbon dioxide-containing gas discharged from the anode chamber of the carbon dioxide electrolysis unit is supplied, and an oxygen permeable membrane type partial oxidation unit including an oxygen permeable membrane disposed between the partial oxidation chamber and the oxygen removal chamber.

Brief Description of the Drawings

[0006] [Figure 1] It is a diagram showing a carbon dioxide conversion device according to the first embodiment. [Figure 2] It is a diagram showing a carbon dioxide conversion device according to the second embodiment. [Figure 3] It is a diagram showing a carbon dioxide conversion device according to the third embodiment;

Modes for Carrying Out the Invention

[0007] The carbon dioxide conversion apparatus of the embodiment will be described below with reference to the drawings. In each embodiment shown below, substantially identical components are denoted by the same reference numerals, and their descriptions may be partially omitted. The drawings are schematic, and the relationship between thickness and planar dimensions, the ratio of the thickness of each part, etc., may differ from reality. In the following description, the symbol "~" indicates the range between the upper and lower limits of each numerical value. In this case, each numerical range includes both the upper and lower limits.

[0008] (First embodiment) Figure 1 shows a carbon dioxide conversion device according to the first embodiment. The carbon dioxide (CO2) conversion device 1 shown in Figure 1 comprises a CO2 recovery unit 2 that recovers CO2 from a carbon dioxide (CO2)-containing gas, a CO2 electrolysis unit 3 that electrolyzes and reduces CO2 to convert it into carbon monoxide (CO), an organic matter synthesis unit 4 that synthesizes organic matter from a raw material gas containing carbon monoxide (CO) and hydrogen (H2) supplied from the CO2 electrolysis unit 3, and an oxygen permeable membrane type partial oxidation unit 5 that partially oxidizes the residual organic matter gas discharged from the organic matter synthesis unit 4 to generate a gas containing CO.

[0009] The CO2 recovery unit 2 is configured to separate and recover CO2 from exhaust gas (CO2-containing gas) G1 emitted from thermal power plants, waste incinerators, steel mills, etc., and to supply the CO2 gas G2 with increased CO2 concentration to the CO2 electrolysis unit 3. Methods such as chemical absorption using a chemical absorbent solution like an amine aqueous solution, solid absorption using a solid absorbent like an amine compound, membrane separation using a CO2 separation membrane, and physical adsorption using inorganic materials like zeolites as adsorbents can be applied to the CO2 recovery unit 2. For example, in a chemical absorption method and apparatus using an amine aqueous solution, exhaust gas G1 is supplied to an absorption tower where the amine aqueous solution is sprayed, and the amine aqueous solution that has absorbed CO2 is heated in a regeneration tower to recover the CO2 released from the amine aqueous solution. The CO2 recovery methods and apparatus applied to the CO2 recovery unit 2 are not particularly limited, and various methods and apparatus capable of recovering CO2 from exhaust gas G1 can be applied.

[0010] The CO2 electrolysis unit 3 is a CO2 electrolysis device having an electrolytic cell, and includes a cathode chamber (reduction section) 6 and an anode chamber (oxidation section) 7. The cathode chamber 6 includes a reduction electrode (cathode), and the anode chamber 7 includes an oxidation electrode (anode). At least the anode chamber 7 is filled or circulated with an electrolytic solution. The cathode chamber 6 may be configured to allow CO2 gas to flow therethrough, or may be configured to circulate or fill an electrolytic solution containing CO2. In the cathode chamber 6 or the anode chamber 7, a solution using water (H2O), for example, an aqueous solution containing an arbitrary electrolyte, is used as the electrolytic solution. Examples of the aqueous solution containing an electrolyte include an aqueous solution containing phosphate ions (PO4 - , , + , , 2+ ,

[0011] , 2+ , - , + , + , - , + , 2- , 2- , - , 3- , + , - , 2- ), borate ions (BO3 3- ), sodium ions (Na + ), potassium ions (K + ), calcium ions (Ca 2+ ), lithium ions (Li[[ID=­11]] + ), cesium ions (Cs + ), magnesium ions (Mg 2+ ), chloride ions (Cl - ), hydrogen carbonate ions (HCO3 - ), carbonate ions (CO3 2- ), hydroxide ions (OH - ), etc. Specific examples of the electrolytic solution include an alkaline aqueous solution in which KOH, KHCO3, K2CO3, etc. are dissolved.

[0011] The cathode chamber 6 is supplied with the CO2 gas G2 recovered by the CO2 recovery unit 2. The cathode chamber 6 has a gas flow path facing a reduction electrode (not shown), and the CO2 gas is supplied to such a gas flow path. The anode chamber 7 has, for example, a liquid flow path facing an oxidation electrode (not shown), and the electrolytic solution is supplied to such a liquid flow path. A power source (not shown) is connected to the reduction electrode and the oxidation electrode. The cathode chamber 6 and the anode chamber 7 are separated by hydrogen ions (H<­ + ), hydroxide ions (OH - ), carbonate ions (CO3<00000­15>), hydrogen carbonate ions (HCO3 -The ions are separated by a diaphragm 8, such as an ion exchange membrane, which is capable of moving ions such as ions. The CO2 electrolysis unit 3 (CO2 electrolysis apparatus having an electrolytic cell) may have a single electrolytic cell or a structure in which they are connected in the planar direction, or it may have a stack structure in which multiple electrolytic cells are stacked and integrated.

[0012] In the cathode chamber 6 and anode chamber 7 of the CO2 electrolysis unit 3, the following reactions occur. In the cathode chamber 6, the electrolytic and reduction reactions of CO2 occur as shown in equation (1) below. In the cathode chamber 6, the reduction reaction of CO2 produces CO and carbonate ions (CO3). 2- ) is generated. 2CO2 + 2e - → CO+CO3 2- …(1) Carbonate ions (CO3) generated in cathode chamber 6 2- ) moves to the anode chamber 7 via the diaphragm 8. In the anode chamber 7, as shown in equation (2) below, carbonate ions (CO3) that were generated in the cathode chamber 6 and moved via the diaphragm 8 move to the anode chamber 7. 2- An oxidation reaction occurs, producing CO2 and O2. CO3 2- → CO2 + 0.5O2 + 2e - …(2)

[0013] Furthermore, in cathode chamber 6, an electrolytic reaction occurs with H2O in the electrolyte, and as shown in equation (3) below, hydrogen (H2) and hydroxide ions (OH) are produced. - ) and are generated. 2H2O + 2e - → H2 + 2OH - …(3) Hydroxide ions (OH) generated in cathode chamber 6 - The ) moves to the anode chamber 7 via the diaphragm 8. Then, as shown in equation (4) below, water (H2O) and oxygen (O2) are produced in the anode chamber 7. 2OH - → 0.5O2 + H2O + 2e - …(4)

[0014] Furthermore, in the anode chamber 7, as shown in equation (5) below, water (H2O) in the electrolyte is electrolyzed to produce oxygen (O2) and hydrogen ions (H + ) and are generated. 2H2O → 4H + +O2+4e - …(5) The generated hydrogen ions (H + The hydrogen ions (H) move to the cathode chamber 6 via the diaphragm 8. + ) reaches and electrons (e - In the cathode chamber 6, where the ions reach, hydrogen is generated by the reaction shown in equation (6) below. 4H + +4e - → 2H2…(6)

[0015] In the cathode chamber 6, CO is generated by the reduction reaction of CO2 shown in equation (1), and H2 is generated by the electrolytic reaction of H2O shown in equation (3) and the reaction shown in equation (6). The CO and H2 generated in the cathode chamber 6 are discharged from the cathode chamber 6 along with the unreacted CO2. The mixed gas G3 containing CO, H2, and CO2 discharged from the cathode chamber 6 is supplied to the organic synthesis unit 4 as part of the raw material gas for the organic synthesis reaction. In addition to the mixed gas G3 containing CO and H2, hydrogen (H2) is supplied to the organic synthesis unit 4 as part of the raw material gas for the organic synthesis reaction.

[0016] In the organic synthesis section 4, organic synthesis reactions, such as the Fischer-Tropsch synthesis reaction, are carried out to synthesize organic substances such as hydrocarbons, alcohols, and other organic substances. Specific examples of organic substances synthesized in the organic synthesis section 4 include carbon-containing liquid fuels. The products (organic substances) from the organic synthesis section 4 are discharged and sent to a storage facility (not shown), such as a separately installed tank. The organic synthesis residue gas G4 is discharged from the organic synthesis section 4. The synthesis residue gas G4 contains unwanted products such as residual CO, H2, CO2, and methane (CH4). This synthesis residue gas G4 is sent to the partial oxidation chamber 10 of the oxygen permeable membrane type partial oxidation section 5.

[0017] On the other hand, in the anode chamber 7 of the CO2 electrolysis unit 3, as shown in equations (2) and (4) above, carbonate ions (CO3 2- ) and hydroxide ions (OH - Oxidation of ) produces oxygen (O2) and carbon dioxide (CO2). The gas containing O2 and CO2 (O2-CO2 containing gas) produced in the anode chamber 7 is discharged from the anode chamber 7 together with the electrolyte. The electrolyte containing the O2-CO2 containing gas is sent to a gas-liquid separation unit 9 located in the discharge piping of the anode chamber 7, where the O2-CO2 containing gas G5 is separated from the electrolyte. The CO2 concentration of the separated O2-CO2 containing gas is high, at 30-60% by volume, so releasing it directly into the atmosphere would hinder the effective utilization of CO2. Since the O2-CO2 containing gas contains a relatively large amount of O2, sending it directly to the cathode chamber 6 would degrade the operation and function of the CO2 electrolysis unit 3. Therefore, the O2-CO2 containing gas G5 discharged from the anode chamber 7 of the CO2 electrolysis unit 3 and separated and recovered in the gas-liquid separation unit 9 is sent to the oxygen removal chamber 11 of the oxygen permeable membrane type partial oxidation unit 5.

[0018] The oxygen permeable membrane type partial oxidation section 5 comprises a partial oxidation chamber 10, an oxygen removal chamber 11, and an oxygen permeable membrane 12 arranged to separate them. As the oxygen permeable membrane 12, a dense solid oxide electrolyte layer is used. The solid oxide electrolyte layer is an ion conductor that allows ions such as oxygen ions to pass through but does not allow gases to pass through. As the solid oxide electrolyte layer, for example, stabilized zirconia in which a stabilizer made of oxides of rare earth elements such as Y, Sc, Ce, Gd, and Sm is solid-dissolved, typically yttria-stabilized zirconia (YSZ) or ceria-stabilized zirconia (CSZ), or composites thereof are used.

[0019] The oxygen permeable membrane type partial oxidation section 5 has a structure in which a partial oxidation chamber 10 as a first electrode chamber having a first electrode and an oxygen removal chamber 11 as a second electrode chamber having a second electrode are separated by an oxygen permeable membrane made of a solid oxide electrolyte layer or the like. The two electrodes are directly connected and short-circuited. The oxygen removal chamber 11 as the second electrode chamber removes oxygen molecules (O2) and oxygen ions (O2). 2- It is responsible for the conversion to ). The partial oxidation chamber 10, which serves as the first electrode chamber, is responsible for the conversion of oxygen ions (O 2- It is responsible for the conversion of ) into oxygen molecules (O2), as well as the partial oxidation of lower hydrocarbons such as methane (CH4).

[0020] In the oxygen permeable membrane type partial oxidation section 5 described above, the O2-CO2-containing gas G5 discharged from the anode chamber 7 of the CO2 electrolysis section 3 is supplied to the oxygen removal chamber 11. In the oxygen removal chamber 11, the O2 in the O2-CO2-containing gas G5 is converted into oxygen ions (O) as shown in equation (7) below. 2- It will be converted to ). O2+4e - → 2O 2- …(7) Oxygen ions converted in oxygen removal chamber 11 (O 2- The oxygen ions (O) sent to the partial oxidation chamber 10 are delivered via the oxygen permeable membrane 12. 2- ) is converted to oxygen molecules (O2) as shown in equation (8) below. 20 2- → O2+4e - …(8)

[0021] In the partial oxidation chamber 10, as shown in equation (9) below, methane (CH4) and other substances contained in the synthesis residue gas G4 are partially oxidized and converted into CO and H2. Partial oxidation refers to a reaction in which, for example, in the oxidation of methane (CH4), partial combustion (partial oxidation) occurs, as shown in equation (9), producing H2-rich CO without oxidizing it to stable CO2. 2CH4 + O2 → 2CO + 4H2…(9) Furthermore, as shown in equation (10) below, CO2 and H2 are converted to CO and H2O by a reverse aqueous shift reaction. CO2 + H2 → CO + H2O …(10)

[0022] From the partial oxidation chamber 10 of the oxygen-permeable membrane type partial oxidation unit 5, a gas containing CO and H2 (CO-H2-containing gas) G6 is discharged. Since the CO-H2-containing gas G6 can be used as part of the raw material gas in the organic synthesis unit 4, it is supplied to the organic synthesis unit 4. From the oxygen removal chamber 11 of the oxygen-permeable membrane type partial oxidation unit 5, an O2-CO2-containing gas (low-concentration O2-CO2-containing gas) G7 with reduced oxygen concentration is discharged. Since the low-concentration O2-CO2-containing gas G7 contains a relatively high concentration of CO2, it is returned to the CO2 recovery unit 2 for reuse. Even though the oxygen concentration of the low-concentration O2-CO2-containing gas G7 has been reduced, it still contains a certain amount of O2. For this reason, the low-concentration O2-CO2-containing gas G7 is returned to the CO2 recovery unit 2, where CO2 is separated and recovered, and the CO2-concentrated CO2 gas G2 is sent to the cathode chamber 6 of the CO2 electrolysis unit 3 for reuse.

[0023] As described above, the synthesis residue gas G4 containing unwanted products such as methane (CH4) is sent to the partial oxidation chamber 10 of the oxygen permeable membrane type partial oxidation unit 5, where methane (CH4) and other substances are partially oxidized to resynthesize CO and H2. This allows the synthesis residue gas G4 to be effectively utilized as part of the raw material gas for the organic matter synthesis unit 4. In addition, the O2-CO2 containing gas G5 discharged from the anode chamber 7 of the CO2 electrolysis unit 3 is supplied to the oxygen removal chamber 11, contributing to the resynthesis of CO and H2 as described above, and reducing the oxygen concentration in the O2-CO2 containing gas G5. This allows the low-concentration O2-CO2 containing gas G7 with a higher CO2 concentration to be returned to the CO2 recovery unit 2, thereby promoting the reuse of CO2. Furthermore, when a chemical absorption method using an amine absorbent is applied to the CO2 recovery unit 2, the O2 concentration in the low-concentration O2-CO2 containing gas G7 is reduced, thereby reducing the thermal energy required for the CO2 recovery unit 2 and suppressing oxygen degradation of the amine absorbent. These measures make it possible to improve the reuse efficiency of CO2-containing gas in the CO2 conversion device 1, and to improve the overall utilization efficiency of the device.

[0024] (Second embodiment) Next, the CO2 conversion device 1 of the second embodiment will be described with reference to Figure 2. The CO2 conversion device 1 of the second embodiment is equipped with an oxygen ion conductive electrolytic device 20 as an oxygen permeable membrane type partial oxidation unit (partial oxidation device). A solid oxide electrolytic cell (SOEC) is used as the oxygen ion conductive electrolytic device 20. The SOEC 20 is equipped with a hydrogen electrode chamber 21, an oxygen electrode chamber 22, and an oxygen permeable membrane 23 arranged to separate them. A dense solid oxide electrolyte layer is used as the oxygen permeable membrane 23. The solid oxide electrolyte layer is an ion conductor that allows ions such as oxygen ions to pass through but does not allow gases to pass through. The hydrogen electrode (cathode) located in the hydrogen electrode chamber 21 and the oxygen electrode (anode) located in the oxygen electrode chamber 22 are connected to a power supply, which is not shown in the figure.

[0025] In SOEC20, the oxygen electrode chamber 22 is supplied with O2-CO2-containing gas G5, which is discharged from the anode chamber 7 of the CO2 electrolysis unit 3 and separated and recovered in the gas-liquid separation unit 9. In the oxygen electrode chamber 22, as shown in equation (7) above, the O2 in the O2-CO2-containing gas G5 is converted into oxygen ions (O 2- It is converted to (O). The oxygen ions converted in oxygen electrode chamber 22 are (O 2- ) are sent to the hydrogen electrode chamber 21 via the oxygen permeable membrane 23. In the hydrogen electrode chamber 21, as shown in equation (8) above, oxygen ions (O 2- ) is converted into oxygen molecules (O2).

[0026] The hydrogen electrode chamber 21 is supplied with the residual organic gas G4 discharged from the organic synthesis section 4. As described above, the residual organic gas G4 contains unwanted products such as remaining CO, H2, CO2, and methane (CH4). In the hydrogen electrode chamber 21, as shown in equation (9) above, the methane (CH4) and other substances contained in the residual organic gas G4 are partially oxidized and converted into CO and H2. Furthermore, as shown in equation (10) above, CO2 and H2 are converted into CO and H2O by a reverse water-water shift reaction.

[0027] As described above, the gas G6 containing CO and H2 (CO-H2-containing gas) discharged from the hydrogen electrode chamber 21 of SOEC20 is supplied to the organic synthesis unit 4 as part of the raw material gas for synthesizing organic substances. The O2-CO2-containing gas (low-concentration O2-CO2-containing gas) G7 with reduced oxygen concentration discharged from the oxygen electrode chamber 22 of SOEC20 is returned to the CO2 recovery unit 2, where CO2 is separated and recovered as CO2 gas G2 and sent to the cathode chamber 6 of the CO2 electrolysis unit 3. In this way, by using SOEC20 to synthesize CO and H2 from methane (CH4) etc. in the residual synthesis gas G4, and to reduce the O2 concentration from the O2-CO2-containing gas G5 discharged from the anode chamber 7, it becomes possible to control the partial oxidation state by adjusting the amount of oxygen transferred with the current value. Furthermore, it becomes possible to improve reactivity by raising the temperature of the reaction unit by Joule heating.

[0028] (Third embodiment) Next, the CO2 conversion device 1 of the third embodiment will be described with reference to Figure 3. The CO2 conversion device 1 of the third embodiment is equipped with an oxygen ion conducting fuel cell 30 as an oxygen permeable membrane type partial oxidation unit (partial oxidation device). A solid oxide fuel cell (SOFC) is used as the oxygen ion conducting fuel cell 30. The SOFC 30 is equipped with a fuel electrode chamber 31, an air electrode chamber 32, and an oxygen permeable membrane 33 arranged to separate them. A dense solid oxide electrolyte layer is used as the oxygen permeable membrane 33. The solid oxide electrolyte layer is an ion conductor that allows ions such as oxygen ions to pass through but does not allow gases to pass through.

[0029] In the SOFC 30, the air electrode chamber 32 is supplied with O2-CO2-containing gas G5 that is discharged from the anode chamber 7 of the CO2 electrolysis unit 3 and separated and recovered in the gas-liquid separation unit 9. In the air electrode chamber 32, as shown in equation (7) above, the O2 in the O2-CO2-containing gas G5 is converted into oxygen ions (O 2- It is converted to oxygen ions (O) converted in the air electrode chamber 32. 2-) are sent to the fuel electrode chamber 31 via the oxygen permeable membrane 32. In the fuel electrode chamber 31, as shown in equation (8) above, oxygen ions (O 2- The CO2 is converted into oxygen molecules (O2). In SOFC30, O2 is consumed. At this time, the O2 concentration in the O2-CO2-containing gas G5 is about 30-60 volume% (for example, 33 volume%), which is higher than the oxygen concentration in air (about 20 volume%), so the power generation efficiency of SOFC30 can be increased. The electricity generated by SOFC30 may be used as part of the electricity consumed in the CO2 electrolysis unit 3.

[0030] The fuel electrode chamber 31 is supplied with the organic synthesis residue gas G4 discharged from the organic synthesis section 4. As described above, the synthesis residue gas G4 contains residual CO, H2, CO2, and unwanted products such as methane (CH4). In the fuel electrode chamber 31, as shown in equation (9) above, the methane (CH4) and other substances contained in the synthesis residue gas G4 are partially oxidized and converted into CO and H2. Furthermore, as shown in equation (10) above, CO2 and H2 are converted into CO and H2O by a reverse water-water shift reaction.

[0031] As described above, by using SOFC30, electricity can be generated from the residual organic gas G4 discharged from the organic synthesis unit 4, and furthermore, methane and other elements in the residual organic gas G4 can be partially oxidized to resynthesize CO and H2, which can be used as raw material gas in the organic synthesis unit 4. The oxygen permeable membrane type partial oxidation unit 5 shown in the first embodiment, the SOEC20 shown in the second embodiment, and the SOFC30 shown in the third embodiment all operate at high temperatures of 600 to 900°C, so it is preferable to recover heat using a heat exchanger (not shown).

[0032] The configurations of each embodiment described above can be applied in combination, and can also be partially replaced. Although several embodiments of the present invention have been described here, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as described in the claims. [Explanation of Symbols]

[0033] 1...CO2 conversion unit, 2...CO2 recovery unit, 3...CO2 electrolysis unit, 4...Organic material synthesis unit, 5...Oxygen permeable membrane type partial oxidation unit, 6...Cathode chamber, 7...Anode chamber, 8...Diaphragm, 10...Partial Oxidation chamber, 11... Oxygen removal chamber, 12, 23, 33... Oxygen permeable membrane, 20... Oxygen ion conducting electrolytic device, 21... Hydrogen electrode chamber, 22... Oxygen electrode chamber, 30... Oxygen ion conducting fuel cell, 31... Fuel electrode chamber, 32... Air electrode chamber.

Claims

1. A carbon dioxide recovery unit that recovers carbon dioxide from carbon dioxide-containing gas, A carbon dioxide electrolysis unit comprising a cathode chamber to which carbon dioxide recovered in the carbon dioxide recovery unit is supplied and which reduces the carbon dioxide to carbon monoxide, and an anode chamber to which oxides are produced by oxidizing an oxide, A carbon monoxide-containing gas is supplied from the cathode chamber of the carbon dioxide electrolysis unit, and an organic matter synthesis unit synthesizes organic matter from a raw material gas containing carbon monoxide-containing gas, An oxygen permeable membrane type partial oxidation unit comprising: a partial oxidation chamber to which the residual gas of the organic matter discharged from the organic matter synthesis unit is supplied; an oxygen removal chamber to which the oxygen-carbon dioxide-containing gas discharged from the anode chamber of the carbon dioxide electrolysis unit is supplied; and an oxygen permeable membrane disposed between the partial oxidation chamber and the oxygen removal chamber. A carbon dioxide conversion device equipped with the following features.

2. The carbon dioxide conversion apparatus according to claim 1, wherein the oxygen permeable membrane type partial oxidation unit is configured to partially oxidize the residual gas from the synthesis of the organic matter in the partial oxidation chamber to generate a gas containing carbon monoxide, and to supply the gas containing carbon monoxide to the organic matter synthesis unit.

3. The carbon dioxide conversion apparatus according to claim 1 or claim 2, wherein the oxygen permeable membrane type partial oxidation unit is configured to discharge carbon dioxide-containing residual gas with reduced oxygen concentration from the oxygen removal chamber and to supply the carbon dioxide-containing residual gas to the carbon dioxide recovery unit.

4. The carbon dioxide conversion apparatus according to claim 1, wherein the oxygen permeable membrane type partial oxidation unit is equipped with an oxygen ion conducting type electrolytic device.

5. The carbon dioxide conversion apparatus according to claim 1, wherein the oxygen permeable membrane type partial oxidation unit comprises an oxygen ion conducting fuel cell.

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