Electrolytic Reactor

Abstract

To provide an electrolysis reactor capable of improving electrolysis processing speed.SOLUTION: An electrolysis reactor 1 has a cathode part 24 having a cathode electrode 22, an anode part 28 having an anode electrode 26, a separating membrane 30 consisting of a cation-exchange membrane that is provided between the cathode part 24 and the anode part 28, a first supply device 12 supplying an electrolyte containing at least one of carbonate ions and hydrogen carbonate ions to the cathode part 24, and a second supply device 14 supplying humidifying carrier gas to the anode part 28, and is characterized in that at least one of a carbon compound and hydrogen (H2) is produced from the cathode part 24 as a product by applying a voltage between the cathode electrode 22 and the anode electrode 26.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to the technology of electrolytic reactors. [Background technology]

[0002] In recent years, from the perspectives of both energy and environmental issues, there has been a demand not only for converting renewable energy such as sunlight into electrical energy for use, but also for converting it into a form that can be stored and transported. In response to this demand, research and development is underway on artificial photosynthesis technology, which uses sunlight to produce chemical substances, similar to the photosynthesis performed by plants. This technology has the potential to store renewable energy as storable fuel, and is also expected to create value by producing chemical substances that can be used as industrial raw materials.

[0003] As a device that generates chemical substances using renewable energy such as sunlight, for example, carbon dioxide (CO2), carbonate ions (CO3 2- ) or bicarbonate ion (HCO 3- Electrolytic reaction devices equipped with a cathode electrode that reduces hydrogen (H 2 O) and an anode electrode that oxidizes water (H 2 O) are known (for example, Patent Documents 1 to 6, Non-Patent Documents 1 to 3). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2019 / 204938 [Patent Document 2] International Publication No. 2021 / 207857 [Patent Document 3] International Publication No. 2020 / 223804 [Patent Document 4] Japanese Patent Publication No. 2021-147679 [Patent Document 5] Patent Publication No. 2021-046576 [Patent Document 6] Japanese Patent Application Publication No. 2018-150596 [Non-patent literature]

[0005] [Non-Patent Document 1] David A. Vermaas and Wilson A. Smith, “Synergistic Electrochemical CO2 Reduction and Water Oxidation with a Bipolar Membrane”, ACS Energy Lett., 1, 1143-1148(2016) [Non-patent document 2] Tengfei Li, Eric W. Lees, Maxwell Goldman, Danielle A. Salvatore, David M. Weekes, and Curtis P. Berlinguette, “Electrolytic Conversion of Bicarbonate into CO in a Flow Cell”, Joule, 3, 1487-1497(2019) [Non-patent document 3] Yuguang C. Li, Geonhui Lee, Tiange Yuan, Ying Wang, Dae-Hyun Nam, Ziyun Wang, F. Pelayo Garcia de Arquer, Yanwei Lum, Cao-Thang Dinh, Oleksandr Voanyy, and Edward H. Sargent, “CO2 Electroreduction from Carbonate Electrolyte”, ACS Energy Lett., 4, 1427-1431(2019) Summary of the Invention [Problem to be solved by the invention]

[0006] In conventional electrolytic reaction devices, liquid water is supplied to an anode electrode to cause an oxidation reaction and generate oxygen (O2). However, the generated oxygen tends to remain at the anode electrode, resulting in a slow electrolytic processing speed.

[0007] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an electrolytic reaction apparatus that can improve the electrolytic treatment speed. [Means for solving the problem]

[0008] The electrolytic reaction device according to this embodiment includes a cathode section having a cathode electrode, an anode section having an anode electrode, a diaphragm made of a cation exchange membrane provided between the cathode section and the anode section, a first supply device that supplies an electrolytic solution containing at least one of carbonate ions and bicarbonate ions to the cathode section, and a second supply device that supplies a humidified carrier gas to the anode section. The electrolytic reaction device is characterized in that at least one of carbon compounds and hydrogen (H2) is produced as a product from the cathode section by applying a voltage between the cathode electrode and the anode electrode.

[0009] The electrolytic reaction device preferably includes a gas-liquid separator that separates the electrolytic solution containing the product discharged from the cathode section into gas and liquid.

[0010] The electrolytic reactor preferably further comprises a gas-liquid contactor that brings a gas containing carbon dioxide into contact with the electrolytic solution obtained through gas-liquid separation by the gas-liquid separator.

[0011] The electrolytic reactor preferably further comprises a circulation device that circulates the electrolyte separated into gas and liquid by the gas-liquid separator to the cathode section.

[0012] In the electrolytic reaction device, the second supply device preferably includes a humidifier that humidifies a carrier gas to generate the humidified carrier gas.

[0013] The electrolytic reaction device preferably further comprises a condenser that condenses the humidified carrier gas discharged from the anode section, and a condensate line that supplies the condensate obtained by the condenser to the humidifier.

[0014] In the electrolytic reaction device, the cathode electrode preferably has a reduction catalyst containing at least one element selected from the group consisting of Sn, In, Co, Au, Ag, Zn, Cu, Pd, Pt, and Mo.

[0015] In the electrolytic reaction device, the anode electrode preferably has an oxidation catalyst containing an oxide containing at least one of Ir, Ru, Pt, and Rh.

[0016] In the electrolytic reactor, the electrolytic solution preferably contains alkali metal ions.

[0017] In the electrolytic reaction apparatus, the humidifier preferably humidifies the carrier gas at a humidification temperature of 80° C. or less.

[0018] In the electrolytic reaction device, the cathode potential (V) of the cathode electrode is preferably lower than −0.06(x+1) (vs. standard hydrogen electrode potential), where x is the pH of the electrolytic solution.

[0019] In the electrolytic reaction device, the voltage applied between the cathode electrode and the anode electrode is preferably 1.29 V or higher. [Effects of the Invention]

[0020] According to the present invention, it is possible to provide an electrolytic reaction device that can improve the electrolytic treatment speed. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a schematic diagram showing an example of an electrolytic reaction device according to an embodiment of the present invention. [Figure 2] 1 is a gas chromatogram of gas products produced on the cathode side in the electrolysis treatments of Examples 1 and 2. [Figure 3] 1 is a gas chromatogram of gas products produced on the cathode side in the electrolysis treatments of Examples 3 and 4. [Figure 4] 1 shows linear sweep voltammograms in electrolysis tests of Example 5 and Comparative Example. DETAILED DESCRIPTION OF THE INVENTION

[0022] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below. The embodiment is an example of implementing the present invention, and the present invention is not limited to this embodiment.

[0023] Fig. 1 is a schematic diagram showing an example of an electrolytic reaction apparatus according to this embodiment. The electrolytic reaction apparatus 1 shown in Fig. 1 includes an electrochemical cell 10, a first supply device 12, and a second supply device 14. The electrolytic reaction apparatus 1 shown in Fig. 1 also preferably includes a gas-liquid separator 16, a gas-liquid contactor 18, and a circulation device 20.

[0024] The electrochemical cell 10 shown in FIG. 1 includes a cathode section 24 having a cathode electrode 22, an anode section 28 having an anode electrode 26, and a diaphragm 30 made of a cation exchange membrane provided between the cathode section 24 and the anode section 28. The cathode section 24 preferably has a flow path 32 through which an electrolyte flows between the diaphragm 30 and the cathode electrode 22. The anode section 28 preferably has a diffusion layer 34 for diffusing a humidified carrier gas on the side of the anode electrode 26 opposite the diaphragm 30. In the electrochemical cell 10 shown in FIG. 1, the anode section 28 and the cathode section 24 are structurally supported by a frame member 36.

[0025] 1 includes an electrolyte solution storage tank 38, an electrolyte solution supply pump 40, and an electrolyte solution supply line 42. The electrolyte solution supply pump 40 is installed in the electrolyte solution supply line 42. One end of the electrolyte solution supply line 42 is connected to the electrolyte solution storage tank 38, and the other end is connected to the flow path 32 of the cathode section 24. The first supply device 12 is not limited to the above configuration as long as it is configured to supply the electrolyte solution described below to the cathode section 24.

[0026] 1 includes a blower 44 and a gas supply line 46. The second supply device 14 also preferably includes a humidifier 48. The blower 44 and the humidifier 48 are installed in the gas supply line 46. The gas supply line 46 is connected to the diffusion layer 34 of the anode section 28. The second supply device 14 is not limited to the above configuration as long as it is configured to supply a humidified carrier gas, which will be described later, to the anode section 28.

[0027] The humidifier 48 includes, for example, a tank for storing water and a heating device for heating the water in the tank, and by heating the water in the tank with the heating device, an amount of moisture corresponding to the heating temperature of the water is contained in a carrier gas such as air passing through the humidifier 48, thereby generating a humidified carrier gas. The humidification temperature (i.e., the heating temperature of the water) by the humidifier 48 is not particularly limited, but is preferably set to, for example, 80°C or less, and more preferably set to 20°C or more and 80°C or less, in order to contain sufficient moisture in the carrier gas.

[0028] 1 includes, for example, a gas-liquid separator 50 and an electrolyte discharge line 52. One end of the electrolyte discharge line 52 is connected to the flow path 32 of the cathode section 24, and the other end is connected to the gas-liquid separator 50. The gas-liquid separator 50 may be, for example, a conventionally known device capable of separating gas and liquid.

[0029] The circulation device 20 includes, for example, a circulation line 54 and a circulation pump 56. The circulation pump 56 is installed in the circulation line 54. One end of the circulation line 54 is connected to the gas-liquid separator 50, and the other end is connected to the electrolyte supply pump 40.

[0030] The gas-liquid contactor 18 includes, for example, a carbon dioxide supply line 58, a gas-liquid contact tank 60, and a discharge line 62. The carbon dioxide supply line 58 is connected to the gas-liquid contact tank 60. One end of the discharge line 62 is connected to the gas-liquid contact tank 60, and the other end is connected to the circulation line 54.

[0031] 1 includes, for example, a gas exhaust line 64 connected to the diffusion layer 34 of the anode section 28. In addition, a condenser 66 is preferably installed in the gas exhaust line 64, and a condensate line 68 is preferably provided between the condenser 66 and the humidifier 48.

[0032] 1 denotes a power supply that applies a voltage between the anode electrode 26 and the cathode electrode 22. The power supply 70 is not particularly limited, and examples thereof include a chemical battery (including a primary battery, a secondary battery, etc.), a constant voltage source, and a solar cell.

[0033] Next, an example of the operation of the electrolytic reaction device 1 shown in FIG. 1 will be described.

[0034] When the electrolyte supply pump 40 is operated, the electrolyte containing carbonate ions and / or bicarbonate ions contained in the electrolyte storage tank 38 is supplied to the flow path 32 of the cathode section 24 through the electrolyte supply line 42. When the blower 44 is operated, a carrier gas such as air passes through the gas supply line 46, is humidified by the humidifier 48, and is supplied to the diffusion layer 34 of the anode section 28 as the humidified carrier gas.

[0035] When a voltage is applied between the cathode electrode 22 and the anode electrode 26 by the power supply 70, when the humidified carrier gas passing through the diffusion layer 34 comes into contact with the anode electrode 26 on the anode section 28 side, for example, water in the humidified carrier gas is oxidized to oxygen (O2) and hydrogen ions (H + ) are produced. On the cathode 24 side, carbonate ions and bicarbonate ions in the electrolyte flowing through the flow path 32 react with protons that have migrated to the cathode 24 side through the diaphragm 30 (cation exchange membrane), for example, to produce carbon dioxide (CO2). On the cathode 24 side, carbonate ions and bicarbonate ions in the electrolyte flowing through the flow path 32 are reduced by, for example, protons that have migrated to the cathode 24 side through the diaphragm 30 (cation exchange membrane), electrons supplied from the power source, and the like, to produce carbon compounds. On the cathode electrode 22, hydrogen (H2) is produced by a reduction reaction of water. Carbon compounds produced by the reduction reaction of carbonate ions, bicarbonate ions, and the like include, for example, carbon monoxide (CO), formic acid (HCOOH), methane (CH4), methanol (CH3OH), ethane (C2H6), ethylene (C2H4), ethanol (C2H5OH), and propanol (C3H7OH). The reduction reaction of carbonate ions, bicarbonate ions, etc. is presumably promoted by protons transferred from the anode side. Furthermore, formate ions are generated by the reduction reaction of carbonate ions, bicarbonate ions, etc., and the reaction of formate ions with protons is presumably also promoted to generate carbon compounds other than formate ions.

[0036] The product produced at the cathode electrode 22 is discharged together with the electrolyte through an electrolyte discharge line 52 and introduced into a gas-liquid separator 50. In the gas-liquid separator 50, for example, gas-liquid separation is performed into a gas containing the product and a liquid (electrolyte) from which the product has been removed, and the gas containing the product is recovered. When the circulation pump 56 is operated, the separated electrolyte is supplied (circulated) to the cathode unit 24 through a circulation line 54. A portion of the separated electrolyte may be transferred to a gas-liquid contact tank 60. Then, a gas containing carbon dioxide is supplied into the gas-liquid contact tank 60 through a carbon dioxide supply line 58, and the electrolyte is brought into contact with the gas containing carbon dioxide, thereby increasing the content of carbonate ions and bicarbonate ions in the electrolyte. The electrolyte after gas-liquid contact is supplied to the cathode unit 24 through, for example, the discharge line 62 and the circulation line 54.

[0037] On the other hand, the humidified carrier gas is discharged, for example, from a gas discharge line 64 and condensed by a condenser 66. The condensed liquid (water, etc.) obtained by the condenser 66 is supplied to the humidifier 48 through a condensate line 68 and is used to humidify the carrier gas.

[0038] The anode electrode 26, the cathode electrode 22, the cation exchange membrane used as the diaphragm 30, the electrolyte, the humidified carrier gas, etc. will be described in detail below.

[0039] As described above, the anode electrode 26 promotes the oxidation reaction of water (H2O) in the humidified carrier gas, and generates oxygen (O2) and hydrogen ions (H + ) is an electrode (oxidation electrode).

[0040] The anode electrode 26 preferably contains an oxidation catalyst. Examples of the oxidation catalyst include metals such as Ru, Ir, Pt, Rh, Co, Ni, and Fe, alloys containing these metals, and oxides containing these metals. Among these, oxides containing at least one of Ru, Ir, Pt, and Rh are preferred because they can reduce the overvoltage of the oxidation reaction. The oxidation catalyst is not limited to the above, and metal hydroxides containing Co, Ni, Fe, Mn, and the like, and metal complexes such as Ru complexes and Fe complexes can also be used. A mixture of multiple materials may also be used.

[0041] The anode electrode 26 may contain both an oxidation catalyst and a conductive material. Examples of the conductive material include carbon materials such as carbon black, activated carbon, fullerene, carbon nanotubes, graphene, ketjen black, and diamond; transparent conductive oxides such as indium tin oxide, fluorine-doped tin oxide, aluminum-doped zinc oxide, and antimony-doped tin oxide; metals such as copper, aluminum, titanium, nickel, silver, tungsten, and gold; and alloys containing at least one of these metals. The anode electrode 26 is formed, for example, by supporting an oxidation catalyst or the like on the diffusion layer 34.

[0042] The diffusion layer 34 is preferably a porous conductive substrate that can efficiently supply the humidified carrier gas to the anode electrode 26. Examples of the porous conductive substrate include a metal porous body or metal mesh made of titanium, a titanium alloy, or stainless steel, or carbon paper.

[0043] As described above, the cathode electrode 22 is an electrode (reduction electrode) that produces carbon compounds and hydrogen (H) when a voltage is applied. The cathode electrode 22 includes a reduction catalyst for producing reduction products such as carbon compounds through a reduction reaction of carbonate ions and bicarbonate ions, for example.

[0044] The reduction catalyst preferably includes at least one element selected from the group consisting of Sn, In, Co, Au, Ag, Zn, Cu, Pd, Pt, and Mo. Specific examples include metals such as Sn, In, Co, Au, Ag, Zn, Cu, Pd, Pt, and Mo, alloys containing these metals, and compounds containing these metals. Mo may also be a sulfide such as MoS2. The reduction catalyst is not limited to the above, and may also be, for example, a carbon material such as graphene, carbon nanotubes, fullerene, or Ketjen Black, a metal complex such as a Ru complex or a Re complex, or an organic molecule having an imidazole or pyridine skeleton. The reduction catalyst may also be a mixture of multiple materials. The cathode electrode 22 may have a structure in which the reduction catalyst is supported on a conductive substrate.

[0045] The cation exchange membrane used as the diaphragm 30 may be a conventionally known membrane, but a membrane having particularly high hydrogen ion conductivity and water permeability is preferred, such as Nafion or Flemion. Note that the diaphragm 30 does not include ion exchange membranes other than cation-cation exchange membranes, such as anion exchange membranes.

[0046] The electrolyte solution supplied to the cathode section 24 is not particularly limited as long as it contains carbonate ions and bicarbonate ions. However, from the viewpoint of stabilizing the carbonate ions and bicarbonate ions, it is preferable that the electrolyte solution contain alkali metal ions. Examples of such electrolyte solutions include aqueous solutions containing alkali metal bicarbonates or alkali metal carbonates, such as lithium bicarbonate (LiHCO), sodium bicarbonate (NaHCO), potassium bicarbonate (KHCO), sodium carbonate (NaCO), potassium carbonate (KCO), and cesium bicarbonate (CsHCO). The concentration of alkali metal ions in the electrolyte solution is preferably in the range of 0.1 M to 3 M, for example, in order to improve the electrolysis rate and enable the electrolysis process to be carried out continuously for a long period of time.

[0047] The electrolyte may contain alcohols such as methanol, ethanol, acetone, etc. The electrolyte may contain a cation such as an imidazolium ion or a pyridinium ion and BF4 - and PF6 - and the like, and may include an ionic liquid that is in a liquid state over a wide temperature range, or an aqueous solution thereof.

[0048] The humidified carrier gas supplied to the anode section 28 is a carrier gas containing moisture. The carrier gas may be air or an inert gas (e.g., nitrogen gas, argon gas, helium gas, etc.). The degree of humidification of the carrier gas may be at least at a level exceeding the humidity of the carrier gas, but it is preferable to increase the moisture content above that of air at 25°C and 50% humidity, for example. Specifically, the moisture content in the humidified carrier gas is 11.5 g / m 3 It is preferable that the above is set.

[0049] For example, in order to improve the electrolysis rate, the cathode potential (V) of the cathode electrode 22 is preferably lower than −0.06(x+1) (vs. standard hydrogen electrode potential), where x is the pH of the electrolytic solution.

[0050] In order to improve the electrolysis rate, the voltage applied between the cathode electrode 22 and the anode electrode 26 is preferably 1.29 V or more. The upper limit of the applied voltage may be, for example, 5 V.

[0051] According to the electrolytic reactor 1 of this embodiment, a humidified carrier gas is supplied to the anode electrode 26 to induce an oxidation reaction and generate oxygen (O). This reduces the likelihood of the generated oxygen remaining at the anode electrode 26 compared to when liquid water is supplied, thereby improving the electrolysis rate. Furthermore, when a humidified carrier gas is supplied to the anode electrode 26, it is not necessary to supply an excessive amount of gas to remove the accumulated oxygen. Furthermore, the pressure loss is lower than when liquid water is supplied, reducing the energy consumption required for the operation of the electrolytic reactor 1. Furthermore, in conventional electrolytic reactors using bipolar membranes, water is ionized into hydrogen ions and hydroxide ions, resulting in a ΔpH between the cathode and anode of approximately 14, which causes a large voltage drop. In contrast, the electrolytic reactor 1 of this embodiment uses a diaphragm 30 composed solely of a cation exchange membrane. This reduces the likelihood of ionization, and the ΔpH between the cathode and anode is approximately 1 to 5 (e.g., the cathode pH is 8 to 12, and the anode pH is 7), thereby reducing the voltage drop. [Example]

[0052] EXAMPLES The present invention will be explained in more detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[0053] Example 1 Electrolysis was carried out using the electrochemical cell shown in Figure 1. The cathode electrode was a gold mesh, and the anode electrode was a Ti mesh on which a 250 nm thick Ir layer was deposited by sputtering. The diaphragm was a DuPont cation exchange membrane, Nafion N115. The geometric area of ​​both the cathode and anode electrodes was 5 cm. 2 When electrolysis was performed, a 3M potassium bicarbonate solution was applied to the cathode at a depth of 3 cm. 3 / min, and humidified helium at 25°C was pumped to the anode at 30cm 3 A voltage of 2.5 V was applied between the cathode and anode electrodes for 1 hour. The average current density during electrolysis was 5.9 mA / cm. 2During this electrolysis, the product gases generated at the cathode electrode were identified and quantified by gas chromatography.

[0054] <Example 2> An electrochemical cell was prepared in the same manner as in Example 1, except that a 0.1 M potassium bicarbonate aqueous solution was used as the electrolyte supplied to the cathode side, and that a 500 nm thick Ag layer was deposited on carbon paper by sputtering as the cathode electrode. Using this electrochemical cell, electrolysis was carried out in the same manner as in Example 1, except that a voltage of 3.5 V was applied between the cathode and anode electrodes for 1 hour. The average current density during electrolysis in Example 2 was 28.9 mA / cm. 2 It was.

[0055] Figure 2 shows gas chromatograms of the gas products produced on the cathode side during the electrolysis in Examples 1 and 2. For comparison, a gas chromatogram of air collected on the same day as the experiment is also shown. In both Examples 1 and 2, hydrogen (H), carbon monoxide (CO), and carbon dioxide (CO) were produced on the cathode side by the electrolysis.

[0056] Example 3 An electrochemical cell was fabricated in the same manner as in Example 1, except that the electrolyte supplied to the cathode side was an aqueous solution containing potassium carbonate at a concentration of 0.64 M and potassium bicarbonate at a concentration of 0.72 M, and the cathode electrode was a carbon paper on which a Pt layer with a thickness of 100 nm had been deposited by sputtering. Using this electrochemical cell, electrolysis was carried out in the same manner as in Example 1, except that a voltage of 2.0 V was applied between the cathode electrode and the anode electrode for 1 hour. The average current density during electrolysis in Example 3 was 0.19 mA / cm. 2 It was.

[0057] Example 4 Electrolysis was carried out in the same manner as in Example 3, except that a voltage of 2.15 V was applied between the cathode and anode electrodes for 1 hour. The average current density during electrolysis in Example 4 was 1.20 mA / cm.2 It was.

[0058] FIG. 3 shows gas chromatograms of gas products generated on the cathode side during the electrolysis in Examples 3 and 4. For comparison, gas chromatograms of air collected on the same day of the experiment are also shown. In both Examples 3 and 4, hydrogen (H2) and carbon dioxide (CO2) were generated from the cathode side by the electrolysis. However, no carbon monoxide was generated. This is thought to be because Pt captured the generated CO or because the applied voltage was low and it was not reduced to CO.

[0059] <Example 5> An electrochemical cell was fabricated in the same manner as in Example 1, except that the electrolyte supplied to the cathode side was an aqueous solution containing 0.5 M potassium carbonate and 1 M potassium bicarbonate, and the cathode electrode was a carbon paper on which a 100 nm thick Pt layer had been deposited by sputtering. Using this electrochemical cell, a voltage of 1.7 to 2.7 V was applied between the cathode and anode electrodes at a scanning rate of 5 mV / s, and the total current density flowing at that time was measured.

[0060] <Comparative Example> Instead of humidified helium at 25°C, add 0.1cm of distilled water. 3 An electrolysis test was carried out in the same manner as in Example 5, except that the flow rate of the electrolyte to the anode was 1 / min, and the total current density flowing at that time was measured.

[0061] Figure 4 shows linear sweep voltammograms from the electrolysis tests of Example 5 and Comparative Example. As shown in Figure 4, it was confirmed that Example 5, in which gaseous water (humidified carrier gas) was supplied, had a higher total current density than the Comparative Example, in which liquid water was supplied to the anode. Therefore, supplying a humidified carrier gas to the anode can improve the electrolysis rate. [Explanation of symbols]

[0062] 1 Electrolytic reactor, 10 Electrochemical cell, 12 First supply device, 14 Second supply device, 16 Gas-liquid separator, 18 Gas-liquid contactor, 20 Circulation device, 22 Cathode electrode, 24 Cathode section, 26 Anode electrode, 28 Anode section, 30 Diaphragm, 32 Flow path, 34 Diffusion layer, 36 Frame material, 38 Electrolyte storage tank, 40 Electrolyte supply pump, 42 Electrolyte supply line, 44 Blower, 46 Gas supply line, 48 Humidifier, 50 Gas-liquid separator, 52 Electrolyte discharge line, 54 Circulation line, 56 Circulation pump, 58 Carbon dioxide supply line, 60 Gas-liquid contactor tank, 62 Discharge line, 64 Gas discharge line, 66 Condenser, 68 Condensate line, 70 Power supply.

Claims

1. a cathode portion having a cathode electrode; an anode portion having an anode electrode; a diaphragm made of a cation exchange membrane provided between the cathode section and the anode section; a first supply device that supplies an electrolyte solution containing at least one of carbonate ions and bicarbonate ions to the cathode portion; a second supply device that supplies a humidified carrier gas to the anode portion, By applying a voltage between the cathode electrode and the anode electrode, carbon compounds and hydrogen (H ２ ) is produced as a product, The electrolytic reaction apparatus further comprises a gas-liquid separation device that separates the electrolytic solution containing the product discharged from the cathode section into gas and liquid, a gas-liquid contactor that brings a gas containing carbon dioxide into contact with the electrolytic solution that has been gas-liquid separated by the gas-liquid separation device, and a circulation device that circulates the electrolytic solution that has been contacted with the gas containing carbon dioxide by the gas-liquid contactor to the cathode section.

2. 2. The electrolytic reactor according to claim 1, wherein the second supply device comprises a humidifier for humidifying a carrier gas to generate the humidified carrier gas.

3. 3. The electrolytic reaction apparatus according to claim 2, further comprising: a condenser that condenses the humidified carrier gas discharged from the anode section; and a condensate line that supplies the condensate obtained by the condenser to the humidifier.

4. The electrolytic reaction device according to any one of claims 1 to 3, characterized in that the cathode electrode has a reduction catalyst containing at least one element selected from the group consisting of Sn, In, Co, Au, Ag, Zn, Cu, Pd, Pt, and Mo.

5. 5. The electrolytic reaction device according to claim 1, wherein the anode electrode has an oxidation catalyst containing an oxide containing at least one of Ir, Ru, Pt, and Rh.

6. 6. The electrolytic reactor according to claim 1, wherein the electrolytic solution contains alkali metal ions.

7. 3. The electrolytic reaction apparatus according to claim 2, wherein the humidifier humidifies the carrier gas at a humidification temperature of 80° C. or less.

8. The electrolytic reaction device according to any one of claims 1 to 7, wherein a cathode potential (V) of the cathode electrode is lower than -0.06(x+1) (vs. standard hydrogen electrode potential), where x is the pH of the electrolytic solution.

9. 9. The electrolytic reaction device according to claim 1, wherein the voltage applied between the cathode electrode and the anode electrode is 1.29 V or more.

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