Electrochemical reaction device

Patent metadata

Field	Value
Publication number	US-11946150-B2
Application number	US-202217881114-A
Country	US
Kind code	B2
Filing date	Aug 4, 2022
Priority date	Sep 19, 2018
Publication date	Apr 2, 2024
Grant date	Apr 2, 2024

Abstract

An electrochemical reaction device in an embodiment includes: a reaction unit including a first accommodation part to accommodate carbon dioxide and a second accommodation part to accommodate an electrolytic solution containing water; a reduction electrode to reduce the carbon dioxide; an oxidation electrode to oxidize the water; a power supply to pass current between the reduction electrode and the oxidation electrode; a pressure regulator to regulate a pressure in the first accommodation part; a reaction product detector to detect at least one of an amount and a kind of a substance produced at the reduction electrode; and a controller to control the pressure regulator based on a detection signal of the reaction product detector.

First claim

What is claimed is:

1. An electrochemical reaction method, comprising:
supplying gas containing carbon dioxide to a gas supply flow path connected to an inlet port of a first flow path in an electrochemical reaction cell so that the gas is in contact with a reduction electrode, and supplying an electrolytic solution containing water to a liquid supply flow path connected to an inlet port of a second flow path in the electrochemical reaction cell so that the electrolytic solution is in contact with an oxidation electrode, wherein the electrochemical reaction cell comprises the reduction electrode, the oxidation electrode, the first flow path arranged to face the reduction electrode, the second flow path arranged to face the oxidation electrode, and a diaphragm provided between the reduction electrode and the oxidation electrode;
applying a voltage from a power supply connected to the reduction electrode and the oxidation electrode, to reduce carbon dioxide and thus produce a carbon compound, and to oxidize water and thus produce oxygen;
discharging the carbon compound from a first gas and liquid discharge flow path connected to an outlet port of the first flow path, and oxygen from a second gas and liquid discharge flow path connected to an outlet port of the second flow path;
detecting continuously at least one of a voltage value and a current value of a current flowing between the reduction electrode and the oxidation electrode to obtain a detection signal indicating an amount and a kind of a substance produced at the reduction electrode; and
regulating a pressure in the first flow path of the electrochemical reaction cell by a first pressure regulator provided in the first gas and liquid discharge flow path based on the detection signal to control the amount and the kind of the substance produced at the reduction electrode so that the pressure in the first flow path becomes 0.1 MPa or more and 6.4 MPa or less when the detection signal does not satisfy a request criterion.

2. The method according to claim 1 , further comprising:
regulating a pressure in the second flow path of the electrochemical reaction cell by a second pressure regulator provided in the second gas and liquid discharge flow path so that a difference between the pressure in the first flow path and the pressure in the second flow path becomes 0.5 MPa or less.

3. The method according to claim 1 , wherein
the power supply comprises a power source which converts kinetic energy or potential energy to electric energy, a power source which converts light energy to electric energy, a power source which converts chemical energy to electric energy, or a power source which converts vibrational energy to electric energy.

4. The method according to claim 1 , wherein
the pressure in the first flow path of the electrochemical reaction cell is regulated to stabilize the amount and the kind of the substance produced at the reduction electrode.

5. The method according to claim 3 , wherein
the pressure in the first flow path of the electrochemical reaction cell is regulated to control the amount and the kind of the substance produced at the reduction electrode when the applied voltage from the power supply fluctuates.

6. The method according to claim 1 , wherein
the pressure regulating comprises comparing the detection signal against the request criterion stored in a storage part, determining whether the detection signal satisfies the request criterion, and outputting a control signal to the first pressure regulator to control the amount and the kind of the substance produced at the reduction electrode when the detection signal does not satisfy the request criterion.

7. The method according to claim 1 , wherein
the detection signal further includes a result of an analysis the substance produced at the reduction electrode.

8. The method according to claim 1 , wherein
the detection signal further includes a potential of the reduction electrode.

9. The method according to claim 8 , wherein
the reduction electrode contains Au as a reduction catalyst, and
the pressure in the first flow path is regulated by the first pressure regulator so that the potential of the reduction electrode becomes in a range of −1.4 V or more and −1.1 V or less on a basis of a reference electrode including Ag/AgCl (3M NaCl).

10. The method according to claim 1 , wherein
the request criterion is decided by a relation between the amount and the kind of the substance produced at the reduction electrode and at least one of the voltage value and the current value of the current flowing between the reduction electrode and the oxidation electrode.

Assignees

• Toshiba Kk

Inventors

• Kitagawa Ryota
• MOTOSHIGE Asahi
• Sugano Yoshitsune
• Yamagiwa Masakazu
• Tamura Jun
• Kudo Yuki
• Ono Akihiko
• Mikoshiba Satoshi

Classifications

• C25B15/025

  of electrolyte parameters · CPC title

• C25B3/26

  of carbon dioxide · CPC title

• C25B1/04

  by electrolysis of water · CPC title

• C25B9/19 Primary

  with diaphragms · CPC title

• C25B15/02 Primary

  Process control or regulation · CPC title