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JP-7856516-B2 - Electrochemical cell

JP7856516B2JP 7856516 B2JP7856516 B2JP 7856516B2JP-7856516-B2

Inventors

  • 辰巳 裕規
  • 松田 信彦
  • 木下 翔太
  • 太田 篤人

Assignees

  • 株式会社デンソー
  • 株式会社SOKEN

Dates

Publication Date
20260511
Application Date
20220715

Claims (6)

  1. A working electrode (130) that performs adsorption and desorption of the gas to be recovered from a mixed gas containing the gas to be recovered by an electrochemical reaction, It comprises a counter electrode (140) that exchanges electrons with the working electrode, The volumetric porosity of the working electrode is greater than or equal to that of the counter electrode. The gas to be recovered is carbon dioxide. The working electrode has a working electrode side electrode film (132), The counter electrode has a counter electrode side electrode film (142), An electrochemical cell in which, of the working electrode side electrode film and the counter electrode side electrode film, only the counter electrode side electrode film is pressure-molded .
  2. The electrochemical cell according to claim 1, wherein the volume porosity of the working electrode side electrode film (132) is greater than or equal to the volume porosity of the counter electrode side electrode film (142).
  3. The working electrode side electrode film is provided with a working electrode side void (137), The counter electrode film is provided with a counter electrode void (147), The electrochemical cell according to claim 2, wherein the average circular equivalent diameter of the working electrode side vacancy is equal to or greater than the average circular equivalent diameter of the counter electrode side vacancy.
  4. The working electrode side electrode film (132) is provided with a working electrode side void (137), The electrochemical cell according to any one of claims 1 to 3, wherein the average circular equivalent diameter of the working electrode side vacancy is four times or more the mean free path of the recovered gas at the operating temperature.
  5. The electrochemical cell according to any one of claims 1 to 3, wherein the thickness of the working electrode side electrode film (132) is less than or equal to the thickness of the counter electrode side electrode film (142).
  6. The electrochemical cell according to any one of claims 1 to 3, wherein the thickness of the working electrode side electrode film (132) is less than or equal to the thickness at which the adsorption rate of the gas to be recovered reaches its upper limit.

Description

This disclosure relates to an electrochemical cell. Patent Document 1 proposes an electrochemical cell used in a carbon dioxide recovery system that separates carbon dioxide ( CO₂ ) from a mixed gas containing carbon dioxide by an electrochemical reaction. In Patent Document 1, by supplying a carbon dioxide-containing gas to the cathode while a potential difference is applied between the cathode and anode of the electrochemical cell, an electrochemical reaction occurs in which CO₂ is converted to CO₃²⁻ and an electrochemical reaction occurs in which CO₃²⁻ is converted to CO₂ . Japanese Patent Application Publication No. 11-33340 This is a conceptual diagram showing the overall configuration of a carbon dioxide capture system in one embodiment.This is an explanatory diagram showing a carbon dioxide capture device in one embodiment.This is a cross-sectional view showing an electrochemical cell in one embodiment.This is an explanatory diagram illustrating the structure of the working electrode.This is an explanatory diagram to illustrate the structure of opposing poles.This is an explanatory diagram illustrating the working pole side vacancy.This is an explanatory diagram for illustrating the void on the opposite side.This figure shows the relationship between the number of cycles and the adsorption Faraday efficiency.This figure shows the relationship between the number of cycles and the cumulative amount of adsorption.This figure shows the relationship between the average circular equivalent diameter of the working electrode vacancy and the molecular diffusion coefficient of carbon dioxide.This figure shows the relationship between the film thickness of the working electrode side electrode film and the calculated carbon dioxide adsorption rate.This figure shows the relationship between the film thickness of the working electrode side electrode film and the measured carbon dioxide adsorption rate.This figure shows the relationship between the film thickness of the working electrode side electrode film and the concentration reached by diffusion. One embodiment of this disclosure will be described with reference to the drawings. This embodiment applies the electrochemical cell of this disclosure to a carbon dioxide recovery system that separates and recovers carbon dioxide from a mixed gas containing carbon dioxide. Therefore, the gas to be recovered in this embodiment is carbon dioxide. As shown in Figure 1, the carbon dioxide recovery system 10 of this embodiment includes a compressor 11, a carbon dioxide recovery device 100, a flow path switching valve 12, a carbon dioxide utilization device 13, and a control device 14. The carbon dioxide capture device 100 is a device that separates and captures carbon dioxide from a mixed gas. The carbon dioxide capture device 100 emits either the carbon dioxide-removed gas (the gas remaining after carbon dioxide has been captured from the mixed gas) or the carbon dioxide captured from the mixed gas. The configuration of the carbon dioxide capture device 100 will be described in detail later. The mixed gas is a carbon dioxide-containing gas. The mixed gas also contains gases other than carbon dioxide. The mixed gas is either the atmosphere or a high-concentration gas with a higher carbon dioxide concentration than the atmosphere. Such high-concentration gases are emitted, for example, from internal combustion engines or factories. In this embodiment, the mixed gas is the atmosphere. The compressor 11 pumps the mixed gas to the carbon dioxide recovery device 100. The flow path switching valve 12 is a three-way valve that switches the flow path of the exhaust gas from the carbon dioxide recovery device 100. When carbon dioxide removal gas is discharged from the carbon dioxide recovery device 100, the flow path switching valve 12 switches the exhaust gas flow path to the atmosphere; when carbon dioxide is discharged from the carbon dioxide recovery device 100, it switches the exhaust gas flow path to the carbon dioxide utilization device 13. The carbon dioxide utilization device 13 is a device that utilizes carbon dioxide. The carbon dioxide utilization device 13 can include, for example, a storage tank for storing carbon dioxide or a conversion device that converts carbon dioxide into fuel. The conversion device can be one that converts carbon dioxide into hydrocarbon fuels such as methane. The hydrocarbon fuel may be a gaseous fuel at room temperature and pressure, or a liquid fuel at room temperature and pressure. The control device 14 is composed of a well-known microcomputer including a CPU, ROM, and RAM, and its peripheral circuits. The control device 14 performs various calculations and processes based on the control program stored in the ROM, and controls the operation of various controlled devices. In this embodiment, the control device 14 performs operation control of the compressor 11, operation control of the carbon dioxide recovery device 100, flow path switching