Electrolysis equipment

Abstract

To provide an electrolytic device which enables production of ammonia without using a hydrogen raw material.SOLUTION: An electrolytic device has an ion exchange part, a first gas diffusion electrode part, a second gas diffusion electrode part, a first gas passage and a second gas passage, wherein in the first gas diffusion electrode part, a first catalyst is carried on a first porous base material, the first catalyst is exposed to a first electrolytic solution, the first porous base material is exposed to nitrogen gas in a first gas passage, in the second gas diffusion electrode part, a second catalyst is carried on a second porous base material, the second catalyst is exposed to a second electrolytic solution, a voltage is applied between the first gas diffusion electrode part and the second gas diffusion electrode part, in a state where the second porous base material is exposed to nitrogen oxide gas in the second gas passage, nitrogen-containing gas is circulated in the first gas passage, and nitrogen oxide-containing gas is circulated in the second gas passage, thereby the nitrogen gas is oxidized on the first catalyst to product nitrogen oxide gas, and the nitrogen oxide gas is reduced on the second catalyst to produce ammonia.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an electrolysis device, and particularly to an electrolysis device for generating ammonia by electrolysis.

Background Art

[0002] In recent years, ammonia has attracted attention as a power generation fuel because it does not emit carbon dioxide even when burned and is a liquid, making it easy to store and transport. Industrially, ammonia is produced by the Haber-Bosch process in which nitrogen and hydrogen are reacted under high temperature and high pressure (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the production of ammonia by the Haber-Bosch process requires hydrogen as a raw material, so it is necessary to produce hydrogen in advance, which has the problem that a large amount of energy is required to produce hydrogen.

[0005] Therefore, an object of the present invention is to provide an electrolysis device capable of producing ammonia without using a hydrogen raw material.

Means for Solving the Problems

[0006] One aspect of the present invention for solving the above-mentioned problems comprises an electrolytic cell, an ion exchange unit, a first gas diffusion electrode unit, a second gas diffusion electrode unit, a first gas flow path through which a nitrogen-containing gas including nitrogen gas flows, a second gas flow path through which a nitrogen oxide-containing gas including nitrogen oxide gas flows, and a power supply device for applying a voltage between the first gas diffusion electrode unit and the second gas diffusion electrode unit, wherein the electrolytic cell is divided into a first tank unit and a second tank unit by the ion exchange unit, the ion exchange unit can restrict the movement between the first tank unit and the second tank unit to the movement of specific ions, the first gas diffusion electrode unit has a first catalyst supported on a first main surface of a first porous substrate, the first catalyst is exposed to a first electrolyte in the first tank unit, and the first porous This electrolytic device has a second main surface of a porous substrate exposed to nitrogen gas in the first gas channel, a second catalyst supported on the first main surface of the second porous substrate in the second gas diffusion electrode section, the second catalyst exposed to a second electrolyte in the second tank section, and the second main surface of the second porous substrate exposed to nitrogen oxide gas in the second gas channel, and with the nitrogen-containing gas flowing through the first gas channel and the nitrogen oxide-containing gas flowing through the second gas channel, a voltage is applied between the first gas diffusion electrode section and the second gas diffusion electrode section to oxidize the nitrogen gas in the nitrogen-containing gas on the first catalyst to produce nitrogen oxide gas, and to reduce the nitrogen oxide gas in the nitrogen oxide-containing gas on the second catalyst to produce ammonia.

[0007] According to this method, ammonia can be produced by electrolyzing nitrogen-containing gas and water, thus enabling ammonia production without the use of hydrogen as a raw material.

[0008] A preferred configuration includes a gas adjustment unit for adjusting the amount of nitrogen oxide-containing gas supplied to the second gas flow path, and a supply flow path for supplying nitrogen oxide gas generated on the first gas diffusion electrode unit to the gas adjustment unit or the second gas flow path.

[0009] According to this configuration, the nitrogen oxide gas generated on the first gas diffusion electrode can be supplied to the gas adjustment unit or the second gas flow path and mixed with the nitrogen oxide-containing gas, thereby being used to generate ammonia on the second gas diffusion electrode.

[0010] A preferred configuration involves circulating the nitrogen-containing gas through the first gas flow path and the nitrogen oxide-containing gas through the second gas flow path, and then applying a voltage between the first gas diffusion electrode and the second gas diffusion electrode to oxidize the first electrolyte and generate hydrogen peroxide.

[0011] According to this method, hydrogen peroxide can be produced in conjunction with the production of ammonia.

[0012] A preferred configuration is that the second electrolyte is water or an aqueous solution.

[0013] According to this configuration, the ammonia generated on the second gas diffusion electrode can be dissolved in the second electrolyte, making it easy to recover the ammonia. [Effects of the Invention]

[0014] According to the present invention, ammonia can be produced without using hydrogen as a raw material. [Brief explanation of the drawing]

[0015] [Figure 1] This is a schematic diagram illustrating the operating principle of the electrolytic device according to the first embodiment of the present invention. [Modes for carrying out the invention]

[0016] Embodiments of the present invention will be described in detail below.

[0017] The electrolytic apparatus 1 of the first embodiment of the present invention mainly produces ammonia and hydrogen peroxide from nitrogen gas and water. As shown in Fig. 1, the electrolysis device 1 includes an electrolytic cell 2, a first gas supply unit 3, a second gas supply unit 5, a gas adjustment unit 6, a first electrolytic solution supply unit 7, a second electrolytic solution supply unit 8, a first storage unit 10, a second storage unit 11, a power supply device 12, a first supply-side piping unit 13, a first recovery-side piping unit 14, a second supply-side piping unit 15, a third supply-side piping unit 16, and a second recovery-side piping unit 17.

[0018] (Electrolytic cell 2) As shown in Fig. 1, the electrolytic cell 2 includes a cell main body portion 20, a first gas diffusion electrode portion 21, a second gas diffusion electrode portion 22, an ion exchange portion 23, a first gas introduction portion 25, a first gas discharge portion 26, a first gas flow path 27, a second gas introduction portion 30, a second gas discharge portion 31, a second gas flow path 32, a first electrolytic solution introduction portion 35, a first electrolytic solution discharge portion 36, a second electrolytic solution introduction portion 37, and a second electrolytic solution discharge portion 38.

[0019] The cell main body portion 20 is partitioned by the ion exchange portion 23 and includes a first cell portion 40 and a second cell portion 41. The first cell portion 40 is a portion between the first gas diffusion electrode portion 21 and the ion exchange portion 23 and is a portion filled with the first electrolytic solution 45. The second cell portion 41 is a portion between the second gas diffusion electrode portion 22 and the ion exchange portion 23 and is a portion filled with the second electrolytic solution 46.

[0020] The first gas diffusion electrode portion 21 is an anode electrode portion that oxidizes nitrogen gas passing through the first gas flow path 27 to generate nitrogen oxide gas. The first gas diffusion electrode portion 21 is composed of a first porous base material 50 and a first catalyst 51, and the first catalyst 51 is supported on the first main surface 52 of the first porous base material 50.

[0021] The first porous base material 50 is a conductive substrate having conductivity and a plurality of voids, and is a substrate that allows gas to pass through in the thickness direction and does not allow liquid to pass through. For the first porous base material 50, polyacrylonitrile-based carbon fibers or the like can be used.

[0022] The first catalyst 51 is an anode catalyst that oxidizes nitrogen gas to form nitrogen oxide gas (NOx). The first catalyst 51 is not particularly limited as long as it oxidizes nitrogen gas to form nitrogen oxide gas (NOx). For example, at least one catalyst selected from IrO2, PtO2, PdO2, and TiO2 proposed in Chem. Sci., 2021, 12, 6442 - 6448 can be considered usable. In particular, a mixed catalyst of Ti2(110) and IrO2(110) is considered preferably usable. The "nitrogen oxide gas (NOx)" mentioned here is a general term for substances in which nitrogen and oxygen are combined, and includes nitrogen monoxide (NO), nitrogen dioxide (NO2), dinitrogen monoxide (N2O), dinitrogen trioxide (N2O3), etc.

[0023] The second gas diffusion electrode part 22 is a cathode electrode part that reduces the nitrogen oxide gas passing through the second gas flow path 32 to generate ammonia. The second gas diffusion electrode part 22 is composed of a second porous base material 60 and a second catalyst 61, and the second catalyst 61 is supported on the first main surface 62 of the second porous base material 60.

[0024] The second porous base material 60 is a conductive substrate having conductivity and a plurality of voids, and is a substrate that allows gas to pass through in the thickness direction and does not allow liquid to pass through. For the second porous base material 60, polyacrylonitrile - based carbon fibers or the like can be used.

[0025] The second catalyst 61 is a cathode catalyst that reduces nitrogen oxide gas (NOx) to form ammonia. The second catalyst 61 is not particularly limited as long as it reduces nitrogen oxide gas (NOx) to form ammonia. For example, nickel phosphide (Ni2P) proposed in Chem. Commun., 2021, 57, 7176 - 7179 can be considered usable.

[0026] The ion exchange part 23 is a separator that partitions the first tank part 40 and the second tank part 41. The ion exchange section 23 is a film that allows only specific ions to move in the thickness direction, while restricting the movement of other ions and electrons. The ion exchange section 23 in this embodiment is a cation exchange membrane that restricts or prevents the movement of anions and electrons, allowing only cations to move. Furthermore, the ion exchange section 23 also serves as a barrier film that blocks the flow of gas in the thickness direction. The ion exchange section 23 is capable of ion exchange, and the material is not particularly limited as long as hydrogen and oxygen do not cross over. For the ion exchange section 23, a polymer membrane such as a perfluoroalkyl sulfonic acid-based polymer membrane like Nafion (registered trademark) can be used.

[0027] The first gas introduction section 25 is the part that introduces nitrogen-containing gas, including nitrogen gas supplied from the first gas supply section 3, into the first gas flow path 27.

[0028] The first gas discharge section 26 is a part that discharges nitrogen-containing gas from the first gas flow path 27 to the outside of the first gas flow path 27.

[0029] The first gas flow path 27 is a flow path connecting the first gas inlet 25 and the first gas outlet 26, and is capable of passing nitrogen-containing gas through it. In the first gas flow path 27, the first gas diffusion electrode section 21 forms part of the inner wall in the intermediate portion in the flow direction.

[0030] The second gas introduction section 30 is the part that introduces nitrogen oxide-containing gas, including nitrogen oxide gas supplied from the gas adjustment section 6, into the second gas flow path 32.

[0031] The second gas discharge section 31 is a part that discharges nitrogen oxide-containing gas from the second gas flow path 32 to the outside of the second gas flow path 32.

[0032] The second gas passage 32 is a passage connecting the second gas inlet 30 and the second gas outlet 31, and is capable of passing nitrogen oxide-containing gas through it. In the second gas flow path 32, the second gas diffusion electrode section 22 forms part of the inner wall in the intermediate portion in the flow direction.

[0033] The first electrolyte introduction section 35 is the part that introduces the first electrolyte 45 supplied from the first electrolyte supply section 7 into the first tank section 40.

[0034] The first electrolyte discharge section 36 is the part that discharges the first electrolyte 45 from inside the first tank section 40 to the first storage section 10.

[0035] The first electrolyte 45 is a liquid containing hydroxide ions, and is not particularly limited as long as it contains hydroxide ions, but for example, water or an alkaline aqueous solution can be used.

[0036] The second electrolyte introduction section 37 is the part that introduces the second electrolyte 46 supplied from the second electrolyte supply section 8 into the second tank section 41.

[0037] The second electrolyte discharge section 38 is the part that discharges the second electrolyte 46 from inside the second tank section 41 to the second storage section 11.

[0038] The second electrolyte 46 is a liquid containing protons, and is not particularly limited as long as it contains protons, but is preferably, for example, water or an acidic solution.

[0039] (1st Gas Supply Department 3) The first gas supply unit 3 is the part that supplies nitrogen-containing gas, including nitrogen gas, from the first gas introduction unit 25 to the first gas flow path 27. The first gas supply unit 3 is capable of adjusting the amount of nitrogen-containing gas supplied to the first gas flow path 27.

[0040] (Second Gas Supply Department 5) The second gas supply unit 5 is the part that supplies nitrogen oxide-containing gas, including nitrogen oxide gas, to the gas adjustment unit 6. The second gas supply unit 5 is capable of adjusting the amount of nitrogen oxide-containing gas supplied to the gas adjustment unit 6.

[0041] (Gas adjustment section 6) The gas adjustment unit 6 is a part that adjusts the amount of nitrogen oxide-containing gas supplied to the second gas flow path 32. The gas adjustment unit 6 mixes the nitrogen oxide-containing gas supplied from the second gas supply unit 5, the nitrogen oxide-containing gas recovered from the first gas flow path 27, and the nitrogen oxide-containing gas recovered from the second gas flow path 32, and is capable of supplying the mixture to the second gas introduction unit 30 at a predetermined flow rate.

[0042] (First electrolyte supply section 7) The first electrolyte supply unit 7 is the part that supplies the first electrolyte 45 from the first electrolyte introduction unit 35 into the first tank unit 40. The first electrolyte supply unit 7 is capable of adjusting the amount of the first electrolyte 45 supplied to the first tank unit 40.

[0043] (Second electrolyte supply section 8) The second electrolyte supply unit 8 is the part that supplies the second electrolyte 46 from the second electrolyte introduction unit 37 into the second tank unit 41. The second electrolyte supply unit 8 is capable of adjusting the amount of the second electrolyte 46 supplied to the second cell unit 41.

[0044] (First storage section 10) The first storage section 10 is a storage tank for storing the first electrolyte 45 containing hydrogen peroxide generated in the first tank section 40. The first storage section 10 preferably has an extraction mechanism for extracting hydrogen peroxide from the first electrolyte 45.

[0045] (Second storage section 11) The second storage section 11 is a storage tank for storing the second electrolyte 46 containing ammonia generated in the second tank section 41. The second storage section 11 preferably has an extraction mechanism for extracting ammonia from the second electrolyte 46.

[0046] (Power supply 12) The power supply unit 12 is a power supply device that supplies power to the electrolytic cell 2, and is a voltage application device that applies a voltage between the first gas diffusion electrode section 21 and the second gas diffusion electrode section 22. The power supply unit 12 is not particularly limited as long as it can apply voltage between the first gas diffusion electrode unit 21 and the second gas diffusion electrode unit 22. The power supply unit 12 may be a commercial power supply unit, a power generation device using renewable energy such as a solar cell, or an energy storage device such as a secondary battery.

[0047] (1st supply side piping section 13) As shown in Figure 1, the first supply side piping section 13 is a piping section that connects the first gas supply section 3 and the first gas introduction section 25, and constitutes a supply channel that supplies nitrogen-containing gas from the first gas supply section 3 to the first gas flow path 27.

[0048] (First recovery side piping section 14) The first recovery side piping section 14 is a piping section that connects the first gas discharge section 26 and the gas adjustment section 6. The first recovery side piping section 14 constitutes a recovery channel for recovering nitrogen oxide gas and unreacted nitrogen-containing gas from the first gas flow path 27, and also constitutes a supply channel for supplying nitrogen oxide gas and unreacted nitrogen-containing gas to the gas adjustment section 6. The first recovery side piping section 14 is equipped with a check valve 70 that allows gas to flow from the first gas discharge section 26 to the gas adjustment section 6, but prevents gas from flowing from the gas adjustment section 6 to the first gas discharge section 26.

[0049] (Second supply side piping section 15) The second supply side piping section 15 is a piping section that connects the second gas supply section 5 and the gas adjustment section 6, and constitutes a supply channel for supplying nitrogen oxide-containing gas from the second gas supply section 5 to the gas adjustment section 6.

[0050] (Third supply side piping section 16) The third supply side piping section 16 is a piping section that connects the gas adjustment section 6 and the second gas introduction section 30, and constitutes a supply channel that supplies nitrogen oxide-containing gas from the gas adjustment section 6 to the second gas flow path 32.

[0051] (Second recovery side piping section 17) The second recovery side piping section 17 is a piping section that connects the second gas discharge section 31 and the gas adjustment section 6. The second recovery side piping section 17 constitutes a recovery channel for recovering unreacted nitrogen oxide gas and nitrogen oxide-containing gas that has not fully reacted from the second gas flow path 32, and also constitutes a supply channel for supplying unreacted nitrogen oxide gas and nitrogen oxide-containing gas that has not fully reacted to the gas adjustment section 6. The second recovery side piping section 17 is equipped with a check valve 71 in the middle that allows gas to flow from the second gas discharge section 31 to the gas adjustment section 6, and prevents gas from flowing from the gas adjustment section 6 to the second gas discharge section 31.

[0052] Next, we will explain the positional relationships of each part of the electrolytic device 1.

[0053] As shown in Figure 1, the electrolytic device 1 has a first gas diffusion electrode section 21 arranged in a first tank section 40, and a second gas diffusion electrode section 22 arranged in a second tank section 41. The surface of the first gas diffusion electrode section 21 facing the first catalyst 51 is opposite the surface of the second gas diffusion electrode section 22 facing the second catalyst 61, with the ion exchange section 23 in between. In the first gas diffusion electrode section 21, the first main surface 52 of the first porous substrate 50 is exposed to the first tank section 40, and the second main surface 53 of the first porous substrate 50 is exposed to the first gas flow path 27. In the second gas diffusion electrode section 22, the first main surface 62 of the second porous substrate 60 is exposed to the second chamber section 41, and the second main surface 63 of the second porous substrate 60 is exposed to the second gas flow path 32.

[0054] The first gas supply unit 3 is connected to the first gas introduction unit 25 via the first supply side piping unit 13. In other words, the electrolytic device 1 has a first supply channel that supplies nitrogen-containing gas from the first gas supply unit 3 to the first gas flow path 27. The second gas supply unit 5 is connected to the gas adjustment unit 6 via the second supply side piping unit 15, and the gas adjustment unit 6 is connected to the second gas introduction unit 30 via the third supply side piping unit 16. In other words, the electrolytic device 1 has a second supply channel that supplies nitrogen oxide-containing gas from the second gas supply unit 5 to the second gas flow path 32 via the gas adjustment unit 6. The first gas discharge section 26 is connected to the gas adjustment section 6 via the first recovery side piping section 14. In other words, the electrolytic device 1 has a third supply channel that supplies nitrogen oxide-containing gas from the first gas channel 27 to the second gas channel 32 via the gas adjustment section 6. The second gas discharge section 31 is connected to the gas adjustment section 6 via the second recovery side piping section 17. In other words, the electrolytic device 1 has a recovery channel that supplies nitrogen oxide-containing gas from the second gas channel 32 to the second gas channel 32 via the gas adjustment unit 6.

[0055] Next, we will describe the operation of generating hydrogen peroxide and ammonia using the electrolytic device 1 of this embodiment.

[0056] First, electrolytes 45 and 46 are supplied from the electrolyte supply units 7 and 8 to the tank units 40 and 41, filling most of the tank units 40 and 41 with electrolytes 45 and 46.

[0057] At this time, the first electrolyte 45 is filled into the first tank section 40, the first gas diffusion electrode section 21 is immersed in the first electrolyte 45 within the first tank section 40, and the first catalyst 51 is exposed to the first electrolyte 45. Similarly, the second electrolyte 46 is filled into the second cell section 41, the second gas diffusion electrode section 22 is immersed in the second electrolyte 46 within the second cell section 41, and the second catalyst 61 is exposed to the second electrolyte 46. The liquid level of the first electrolyte 45 is preferably such that 80% or more of the first catalyst 51 of the first gas diffusion electrode section 21 is immersed, and more preferably such that 90% or more is immersed. The liquid level of the second electrolyte 46 is preferably such that 80% or more of the second catalyst 61 of the second gas diffusion electrode section 22 is immersed, and more preferably such that 90% or more is immersed.

[0058] In addition, in a separate process, nitrogen-containing gas is supplied from the first gas supply unit 3 to the first gas flow path 27, and nitrogen oxide-containing gas is supplied from the second gas supply unit 5 to the second gas flow path 32 via the gas adjustment unit 6.

[0059] At this time, the first porous substrate 50 of the first gas diffusion electrode section 21 has its second main surface 53 exposed to the nitrogen-containing gas flowing through the first gas channel 27, and the second porous substrate 60 of the second gas diffusion electrode section 22 has its second main surface 63 exposed to the nitrogen oxide-containing gas flowing through the second gas channel 32.

[0060] Then, with nitrogen-containing gas flowing through the first gas flow path 27 and nitrogen oxide-containing gas flowing through the second gas flow path 32, a voltage is applied between the first gas diffusion electrode section 21 and the second gas diffusion electrode section 22 by the power supply unit 12.

[0061] At this time, an electrochemical reaction according to the following reaction equation (1) occurs on the first catalyst 51 of the first gas diffusion electrode section 21, producing nitrogen oxide gas, hydrogen peroxide, and water. Also, an electrochemical reaction according to the following reaction equation (2) occurs on the second catalyst 61 of the second gas diffusion electrode section 22, producing ammonia and water. As a result, the overall reaction is one in which nitrogen gas and water react to produce ammonia and hydrogen peroxide, as shown in the following reaction equation (3).

[0062] [ka]

[0063] At this time, the hydrogen peroxide and water generated in the first gas diffusion electrode section 21 dissolve in the first electrolyte 45, and the nitrogen oxide gas and unreacted nitrogen-containing gas flow downstream of the first gas flow path 27, are discharged to the outside from the first gas discharge section 26, and are recovered in the gas adjustment section 6 from the first recovery side piping section 14. The ammonia and water generated in the second gas diffusion electrode section 22 dissolve in the second electrolyte 46, and the unreacted nitrogen oxide-containing gas flows downstream of the second gas flow path 32, is discharged to the outside from the second gas discharge section 31, and is recovered in the gas adjustment section 6 from the second recovery side piping section 17.

[0064] The first electrolyte 45, in which hydrogen peroxide is dissolved, is discharged from the first electrolyte discharge section 36 to the first storage section 10 and stored in the first storage section 10, while the second electrolyte 46, in which ammonia is dissolved, is discharged from the second electrolyte discharge section 38 to the second storage section 11 and stored in the second storage section 11. Subsequently, hydrogen peroxide can be separated from the first electrolyte 45 and ammonia from the second electrolyte 46 as needed, thereby obtaining high-purity hydrogen peroxide and high-purity ammonia.

[0065] According to the electrolytic apparatus 1 of the first embodiment, by applying a voltage between the first gas diffusion electrode section 21 and the second gas diffusion electrode section 22 while a nitrogen-containing gas is flowing through the first gas flow path 27 and a nitrogen oxide-containing gas is flowing through the second gas flow path 32, the nitrogen gas in the nitrogen-containing gas is oxidized on the first catalyst 51 to produce nitrogen oxide gas, and the nitrogen oxide gas in the nitrogen oxide-containing gas is reduced on the second catalyst 61 to produce ammonia. Therefore, ammonia can be produced without using hydrogen as a raw material.

[0066] According to the electrolytic apparatus 1 of the first embodiment, a first recovery-side piping section 14 is provided for supplying nitrogen oxide gas generated on the first gas diffusion electrode section 21 to the gas adjustment section 6. Therefore, the nitrogen oxide gas generated on the first gas diffusion electrode section 21 is supplied to the gas adjustment section 6 and mixed with nitrogen oxide-containing gas for use in the generation of ammonia on the second gas diffusion electrode section 22.

[0067] According to the electrolytic apparatus 1 of the first embodiment, by applying a voltage between the first gas diffusion electrode section 21 and the second gas diffusion electrode section 22 while a nitrogen-containing gas is flowing through the first gas flow path 27 and a nitrogen oxide-containing gas is flowing through the second gas flow path 32, the first electrolyte 45 is oxidized to produce hydrogen peroxide. Therefore, hydrogen peroxide can be produced in conjunction with the production of ammonia.

[0068] According to the electrolytic apparatus 1 of the first embodiment, since the second electrolyte 46 can dissolve ammonia, ammonia generated on the second gas diffusion electrode section 22 can be easily recovered by dissolving it in the second electrolyte 46.

[0069] According to the electrolytic apparatus 1 of the first embodiment, since the first electrolyte 45 can dissolve hydrogen peroxide, hydrogen peroxide generated on the first gas diffusion electrode section 21 can be easily recovered by dissolving it in the first electrolyte 45.

[0070] In the embodiment described above, unreacted nitrogen-containing gas and nitrogen oxide gas were supplied from the first gas flow path 27 to the gas adjustment unit 6 via the first recovery side piping section 14, but the present invention is not limited thereto. Unreacted nitrogen-containing gas and nitrogen oxide gas may also be supplied directly from the first gas flow path 27 to the second gas flow path 32 via the first recovery side piping section 14.

[0071] In the embodiments described above, the nitrogen oxide-containing gas generated in the first gas diffusion electrode section 21 was recovered and used in the second gas diffusion electrode section 22, but the present invention is not limited thereto. The nitrogen oxide-containing gas generated in the first gas diffusion electrode section 21 does not need to be used in the second gas diffusion electrode section 22.

[0072] In the embodiment described above, nitrogen oxide-containing gas that was not used for ammonia generation on the second gas diffusion electrode section 22 was recovered from the second gas flow path 32 by the gas adjustment section 6 and supplied back to the second gas diffusion electrode section 22. However, the present invention is not limited thereto. It is not necessary to recover nitrogen oxide-containing gas that was not used for ammonia generation on the second gas diffusion electrode section 22 from the second gas flow path 32 by the gas adjustment section 6.

[0073] In the embodiment described above, hydrogen peroxide was generated on the first gas diffusion electrode section 21 in conjunction with the oxidation reaction of nitrogen, but the present invention is not limited thereto. Hydrogen may also be generated on the first gas diffusion electrode section 21 in conjunction with the oxidation reaction of nitrogen.

[0074] In the embodiments described above, the components can be freely substituted or added between each embodiment, as long as they fall within the technical scope of the present invention. [Explanation of Symbols]

[0075] 1 Electrolyzer 2 Electrolytic cell 6. Gas adjustment section 12 Power supply 14. First recovery side piping section (supply channel) 21 First gas diffusion electrode section 22 Second gas diffusion electrode section 23 Ion exchange section 27 First gas flow path 32 Second gas channel 40 1st tank section 41 Second tank section 45 First electrolyte 46 Second electrolyte 50 First porous base material 51 First Catalyst 52 First Main Surface 53 Second Main Surface 60 Second porous base material 61 Second Catalyst 62 First Main Surface 63 Second Main Surface

Claims

1. An electrolytic cell having an ion exchange section, a first gas diffusion electrode section, a second gas diffusion electrode section, a first gas channel through which a nitrogen-containing gas including nitrogen gas flows, and a second gas channel through which a nitrogen oxide-containing gas including nitrogen oxide gas flows, The system includes a power supply device that applies a voltage between the first gas diffusion electrode and the second gas diffusion electrode, The electrolytic cell is divided into a first tank section and a second tank section by the ion exchange section. The ion exchange unit is capable of restricting the movement between the first tank and the second tank to the movement of specific ions. The first gas diffusion electrode portion has a first catalyst supported on a first main surface of a first porous substrate, the first catalyst exposed to a first electrolyte in the first tank portion, and the second main surface of the first porous substrate exposed to nitrogen gas in the first gas flow path. In the second gas diffusion electrode section, the second catalyst is supported on the first main surface of the second porous substrate, the second catalyst is exposed to the second electrolyte within the second tank section, and the second main surface of the second porous substrate is exposed to nitrogen oxide gas within the second gas flow path. With the nitrogen-containing gas flowing through the first gas channel and the nitrogen oxide-containing gas flowing through the second gas channel, applying a voltage between the first gas diffusion electrode and the second gas diffusion electrode makes it possible to oxidize the nitrogen gas in the nitrogen-containing gas on the first catalyst to generate nitrogen oxide gas, and to reduce the nitrogen oxide gas in the nitrogen oxide-containing gas on the second catalyst to generate ammonia. The electrolytic cell has a first gas discharge section that discharges nitrogen oxide-containing gas, including nitrogen oxide gas generated on the first gas diffusion electrode section, to the outside from the first gas flow path. An electrolytic apparatus further comprising a gas adjustment unit for adjusting the amount of nitrogen oxide-containing gas supplied to the second gas flow path, and a supply flow path for supplying nitrogen oxide-containing gas discharged from the first gas discharge unit to the second gas flow path directly or via the gas adjustment unit.

2. The electrolytic cell has a second gas discharge section that discharges nitrogen oxide-containing gas to the outside from the second gas flow path, The electrolytic apparatus according to claim 1, further comprising a recovery channel for supplying nitrogen oxide-containing gas discharged from the second gas discharge section to the second gas flow path via the gas adjustment section.

3. The electrolytic apparatus according to claim 1 or 2, wherein the nitrogen-containing gas is circulated through the first gas flow path and the nitrogen oxide-containing gas is circulated through the second gas flow path, and a voltage is applied between the first gas diffusion electrode and the second gas diffusion electrode to oxidize the first electrolyte and generate hydrogen peroxide.

4. Further comprising a second storage section, The electrolytic cell has a second electrolyte discharge section that discharges the second electrolyte from the inside of the second tank section to the second storage section. The electrolytic apparatus according to claim 1 or 2, wherein the second electrolyte is water or an aqueous solution.

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