Synthesis gas production system

Patent metadata

Field	Value
Publication number	US-11268198-B2
Application number	US-201816643858-A
Country	US
Kind code	B2
Filing date	Jun 27, 2018
Priority date	Sep 5, 2017
Publication date	Mar 8, 2022
Grant date	Mar 8, 2022

Abstract

A synthesis gas production system for producing CO and H2 by electrolyzing an aqueous solution containing CO2 includes: an electrolysis device including an anode chamber and a cathode chamber separated by a separator membrane; a cathode-side circulation line connected to the cathode chamber to circulate a cathode solution containing CO2; a catalyst supply device provided in the cathode-side circulation line to supply a CO production catalyst to the cathode solution; and a gas composition detection device configured to measure a ratio between CO and H2 in a production gas produced in the cathode chamber. At least one of control of a supply amount of the CO production catalyst by the catalyst supply device and control of a voltage applied between the anode and the cathode by the electrolysis device is performed to make a ratio of H2 to CO in the production gas be within a predetermined target range.

First claim

The invention claimed is:

1. A synthesis gas production system for producing CO and H 2 by electrolyzing an aqueous solution containing CO 2 , comprising:
an electrolysis device including an anode chamber having an anode, a cathode chamber having a cathode, and a separator membrane separating the anode chamber and the cathode chamber;
a cathode-side circulation line connected to the cathode chamber to circulate a cathode solution containing CO 2 ;
a catalyst supply device provided in the cathode-side circulation line to supply a CO production catalyst to the cathode solution; and
a gas composition detection device configured to measure a ratio between CO and H 2 in a production gas produced in the cathode chamber,
wherein based on a result of the gas composition detection device, at least one of control of a supply amount of the CO production catalyst by the catalyst supply device and control of a voltage applied between the anode and the cathode by the electrolysis device is performed to make a ratio of H 2 to CO in the production gas be within a predetermined target range.

2. The synthesis gas production system according to claim 1 , further comprising:
a bypass line provided in parallel with the cathode-side circulation line and having an upstream end and a downstream end connected to the cathode-side circulation line;
a flow rate control valve configured to control a flow rate of the cathode solution flowing through the bypass line; and
a solid-liquid separation device provided in the bypass line.

3. The synthesis gas production system according to claim 1 , wherein the target range is set to be greater than or equal to 0.25 and less than or equal to 2.5 for a mole ratio of H 2 to CO.

4. The synthesis gas production system according to claim 1 , wherein the CO production catalyst is supplied to the cathode solution in a state of at least one of powder, aqueous solution, and suspension.

5. The synthesis gas production system according to claim 1 , wherein the CO production catalyst includes at least one of a group consisting of Zn, ZnO, ZnO 2 , ZnO 3 , ZnSO 4 , Zn(NO 3 ) 2 , ZnCl 2 , ZnBr 2 , ZnI 2 , Zn(OCOCH 3 ) 2 , Ag, AgO, Ag 2 O, Ag 2 O 3 , AgNO 3 , AgCl, AgBr, Ag(OCOCH 3 ), Au, AuCl, AuCl 3 , H[AuCl 4 ], AuBr 3 , H[AuBr 4 ], Au(OCOCH 3 ), and Au(OCOCH 3 ) 3 .

6. The synthesis gas production system according to claim 1 , wherein the cathode solution includes at least one of a group consisting of LiOH, NaOH, KOH, Li 2 CO 3 , Na 2 CO 3 , K 2 CO 3 , LiHCO 3 , NaHCO 3 , and KHCO 3 .

7. The synthesis gas production system according to claim 1 , further comprising a carbon dioxide absorption tank provided in the cathode-side circulation line and configured to cause gaseous CO 2 to contact the cathode solution and to make the cathode solution absorb the CO 2 .

8. The synthesis gas production system according to claim 1 , further comprising a gas-liquid separation device provided in the cathode-side circulation line and configured to separate the production gas and the cathode solution.

9. The synthesis gas production system according to claim 1 , further comprising an anode-side circulation line connected to the anode chamber independently of the cathode-side circulation line to circulate an anode solution.

10. A synthesis gas production system for producing CO and H 2 by electrolyzing an aqueous solution containing CO 2 , comprising:
an electrolysis device including an anode chamber having an anode, a cathode chamber having a cathode, and a separator membrane separating the anode chamber and the cathode chamber;
a cathode-side circulation line connected to the cathode chamber to circulate a cathode solution containing CO 2 ;
a catalyst supply device provided in the cathode-side circulation line to supply a CO production catalyst to the cathode solution;
a gas composition detection device configured to measure a ratio between CO and H 2 in a production gas produced in the cathode chamber;
a bypass line provided in parallel with the cathode-side circulation line and having an upstream end and a downstream end connected to the cathode-side circulation line;
a flow rate control valve configured to control a flow rate of the cathode solution flowing through the bypass line; and
a solid-liquid separation device provided in the bypass line,
wherein based on a result of the gas composition detection device, at least one of control of a supply amount of the CO production catalyst by the catalyst supply device, control of a flow rate of the cathode solution supplied to the solid-liquid separation device by the flow rate control valve, and control of a voltage applied between the anode and the cathode by the electrolysis device is performed to make a ratio of H 2 to CO in the production gas be within a predetermined target range.

11. The synthesis gas production system according to claim 10 , wherein the target range is set to be greater than or equal to 0.25 and less than or equal to 2.5 for a mole ratio of H 2 to CO.

12. The synthesis gas production system according to claim 10 , wherein the CO production catalyst is supplied to the cathode solution in a state of at least one of powder, aqueous solution, and suspension.

13. The synthesis gas production system according to claim 10 , wherein the CO production catalyst includes at least one of a group consisting of Zn, ZnO, ZnO 2 , ZnO 3 , ZnSO 4 , Zn(NO 3 ) 2 , ZnCl 2 , ZnBr 2 , ZnI 2 , Zn(OCOCH 3 ) 2 , Ag, AgO, Ag 2 O, Ag 2 O 3 , AgNO 3 , AgCl, AgBr, Ag(OCOCH 3 ), Au, AuCl, AuCl 3 , H[AuCl 4 ], AuBr 3 , H[AuBr 4 ], Au(OCOCH 3 ), and Au(OCOCH 3 ) 3 .

14. The synthesis gas production system according to claim 10 , wherein the cathode solution includes at least one of a group consisting of LiOH, NaOH, KOH, Li 2 CO 3 , Na 2 CO 3 , K 2 CO 3 , LiHCO 3 , NaHCO 3 , and KHCO 3 .

15. The synthesis gas production system according to claim 10 , further comprising a carbon dioxide absorption tank provided in the cathode-side circulation line and configured to cause gaseous CO 2 to contact the cathode solution and to make the cathode solution absorb the CO 2 .

16. The synthesis gas production system according to claim 10 , further comprising a gas-liquid separation device provided in the cathode-side circulation line and configured to separate the production gas and the cathode solution.

17. The synthesis gas production system according to claim 10 , further comprising an anode-side circulation line connected to the anode chamber independently of the cathode-side circulation line to circulate an anode solution.

Assignees

• Chiyoda Corp

Inventors

• Matsumoto Jun
• Takeda Dai

Classifications

• C25B1/23 Primary

  Carbon monoxide or syngas · CPC title

• B01J27/232

  Carbonates · CPC title

• C25B11/033

  Liquid electrodes · CPC title

• C25B15/087

  Recycling of electrolyte to electrochemical cell · CPC title

• C25B11/081

  the element being a noble metal · CPC title