Photoelectrochemical reaction system

Patent metadata

Field	Value
Publication number	US-2016369409-A1
Application number	US-201615249988-A
Country	US
Kind code	A1
Filing date	Aug 29, 2016
Priority date	Mar 24, 2014
Publication date	Dec 22, 2016
Grant date	—

Abstract

A photoelectrochemical reaction system of an embodiment includes: a CO 2 generation unit, a CO 2 reduction unit, and a CO 2 supply unit supplying gas containing CO 2 generated in the CO 2 generation unit into the CO 2 reduction unit. The CO 2 reduction unit includes: a stack 3 including an oxidization electrode layer 11 oxidizing H 2 O, a reduction electrode layer 21 reducing CO 2 , and a photovoltaic layer 31 provided between the electrode layers 11, 21; an electrolytic solution tank 2 storing a first electrolytic solution 4 in which the oxidization electrode layer 11 is immersed and a second electrolytic solution 5 in which the reduction electrode layer 21 is immersed; and an ion migration pathway 6 allowing ions to migrate between the first electrolytic solution 4 and the second electrolytic solution 5. The gas containing CO 2 generated in the CO 2 generation unit is supplied into the second electrolytic solution 5 by a gas supply pipe 51 of the CO 2 supply unit.

First claim

What is claimed is:

1 . A photoelectrochemical reaction system, comprising:
a CO 2 generation unit generating gas containing carbon dioxide; a CO 2 reduction unit comprising: a stack including an oxidization electrode layer oxidizing water, a reduction electrode layer reducing carbon dioxide, and a photovoltaic layer provided between the oxidization electrode layer and the reduction electrode layer, and performing a charge separation by light energy; an electrolytic solution tank storing a first electrolytic solution in which the oxidization electrode layer is immersed and a second electrolytic solution in which the reduction electrode layer is immersed; and an ion migration pathway allowing ions to migrate between the first electrolytic solution and the second electrolytic solution; and a CO 2 supply unit comprising a gas supply pipe supplying the gas generated in the CO 2 generation unit into the second electrolytic solution.

2 . The system of claim 1 , wherein the gas supply pipe is immersed in the second electrolytic solution, and has a gas supply hole which releases the gas introduced from the CO 2 generation unit into the second electrolytic solution.

3 . The system of claim 1 , wherein the CO 2 supply unit supplies the gas exhausted from the CO 2 generation unit into the second electrolytic solution by an exhaust pressure of the gas.

4 . The system of claim 1 , wherein the stack further comprises an oxidation catalyst layer provided on the oxidization electrode layer and a reduction catalyst layer provided on the reduction electrode layer.

5 . The system of claim 1 , wherein the CO 2 reduction unit reduces the carbon dioxide to generate a carbon compound and oxidizes water to generate oxygen and hydrogen ions.

6 . The system of claim 5 , further comprising:
a product collection unit collecting the carbon compound generated in the CO 2 reduction unit.

7 . The system of claim 6 , wherein the carbon compound generated in the CO 2 reduction unit is sent from the CO 2 reduction unit to the product collection unit by a pressure of the gas released from the gas supply pipe.

8 . The system of claim 6 , further comprising
a CO 2 separation unit separating carbon dioxide from the carbon compound generated in the CO 2 reduction unit.

9 . The system of claim 8 , further comprising:
an impurity removal unit removing an impurity from the gas exhausted from the CO 2 generation unit, wherein the CO 2 supply unit supplies the gas from which the impurity has been removed in the impurity removal unit, into the second electrolytic solution.

10 . The system of claim 9 , further comprising
a CO 2 absorption unit absorbing at least one of the gas from which the impurity has been removed in the impurity removal unit and the carbon dioxide gas separated from the carbon compound in the CO 2 separation unit.

11 . The system of claim 1 , wherein the CO 2 reduction unit reduces water together with the carbon dioxide to generate a mixture of a carbon compound and hydrogen, and oxidizes water to generate oxygen and hydrogen ions.

12 . The system of claim 11 , further comprising:
an impurity removal unit removing an impurity from the gas exhausted from the CO 2 generation unit; a CO 2 separation unit separating carbon dioxide from the mixture of the carbon compound and hydrogen generated in the CO 2 reduction unit; a product collection unit collecting the mixture of the carbon compound and hydrogen produced in the CO 2 reduction unit; and a CO 2 absorption unit absorbing at least one of the gas from which the impurity has been removed in the impurity removal unit and the carbon dioxide gas separated from the carbon compound in the CO 2 separation unit.

13 . The system of claim 1 , wherein the photovoltaic layer has at least one of a pin-junction semiconductor and a pn-junction semiconductor.

14 . The system of claim 1 , wherein the CO 2 reduction unit comprises the stack in a tubular shape arranged around the gas supply pipe and the electrolytic solution tank in a tubular shape arranged around the stack in the tubular shape.

15 . A photoelectrochemical reaction system, comprising:
a CO 2 generation unit generating gas containing carbon dioxide; a CO 2 reduction unit comprising: a stack including an oxidization electrode layer oxidizing water, a reduction electrode layer reducing carbon dioxide, and a photovoltaic layer provided between the oxidization electrode layer and the reduction electrode layer, and performing a charge separation by light energy; an electrolytic solution tank storing a first electrolytic solution in which the oxidization electrode layer is immersed and a second electrolytic solution in which the reduction electrode layer is immersed; and an ion migration pathway allowing ions to migrate between the first electrolytic solution and the second electrolytic solution, the CO 2 reduction unit reducing the carbon dioxide to generate a carbon compound and oxidizing water to generate oxygen and hydrogen ions; a CO 2 supply unit comprising a gas supply pipe supplying the gas generated in the CO 2 generation unit into the second electrolytic solution; and a product collection unit collecting the carbon compound generated in the CO 2 reduction unit, wherein the carbon compound generated in the CO 2 reduction unit is sent from the CO 2 reduction unit to the product collection unit by a pressure of the gas containing the carbon dioxide released from the gas supply pipe.

Assignees

• Toshiba Kk

Inventors

• Kudo Yuki
• Mikoshiba Satoshi
• Ono Akihiko
• Tamura Jun
• Tsutsumi Eishi
• Kitagawa Ryota
• Huang Chingchun
• Sugano Yoshitsune

Classifications

• C25B1/04

  by electrolysis of water · CPC title

• H01G9/20

  Light-sensitive devices · CPC title

• C25B15/08 Primary

  Supplying or removing reactants or electrolytes; Regeneration of electrolytes · CPC title

• C25B9/00

  Cells or assemblies of cells; Constructional parts of cells; Assemblies of constructional parts, e.g. electrode-diaphragm assemblies; Process-related cell features · CPC title

• C25B3/04

  Chemistry & Metallurgy · mapped topic