US 2025/0018339 A1Published application

Method and apparatus for carbon capture coupled hydrogen production

AssigneeXeca Turbo Technologies (Beijing) Co., Ltd.

InventorsXijia LV, Shuxian ZHUANG, Junwei ZHANG, Hao ZHANG, Tu ZHAO, Yifan LIU, Shen CHEN, Yakui BAI

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Abstract

Disclosed are a method and an apparatus for carbon capture coupled hydrogen production. The method includes: capturing low-concentration CO2 by a solution of an alkali metal hydroxide to obtain a low-concentration CO2 absorption solution; capturing high-concentration CO2 by a first portion of the low-concentration CO2 absorption solution to obtain a high-concentration CO2 absorption solution; and performing electrolysis by a second portion of the low-concentration CO2 absorption solution as a catholyte solution, using the high-concentration CO2 absorption solution as an anolyte, and using a non-ionic diaphragm as a diaphragm. According to the method, capture of CO2 in a wide concentration range can be realized; electrolysis is performed by a non-ionic diaphragm, to implement regeneration of an absorption solution coupled hydrogen production; capture costs of CO2 in a wide concentration range can be reduced; additional products of H2 and O2 can be obtained; and hydrogen production costs can be reduced.

Claims15

Dependent claims

A method for carbon capture coupled hydrogen production, comprising the following steps:

step S1:
capturing low-concentration CO2 by using a solution of an alkali metal hydroxide, to obtain a low-concentration CO2 absorption solution, wherein the low-concentration CO2 absorption solution comprises an alkali metal carbonate and the alkali metal hydroxide;
step S2:
dividing the low-concentration CO2 absorption solution into a first portion of the low-concentration CO2 absorption solution and a second portion of the low-concentration CO2 absorption solution;
and capturing high-concentration CO2 by using the first portion of the low-concentration CO2 absorption solution, to obtain a high-concentration CO2 absorption solution, wherein the high-concentration CO2 absorption solution comprises the alkali metal carbonate and an alkali metal bicarbonate;
and
step S3:
performing electrolysis by using the second portion of the low-concentration CO2 absorption solution as a catholyte solution, using the high-concentration CO2 absorption solution as an anolyte solution, and using a non-ionic diaphragm as a diaphragm, to obtain H2 and a cathodic discharge liquid at an electrolytic cathode, and obtain O2, CO2, and an anodic discharge liquid at an electrolytic anode;
and performing step S1 by using the cathodic discharge liquid, wherein the cathodic discharge liquid comprises the alkali metal carbonate and the alkali metal hydroxide;
and
the anodic discharge liquid comprises the alkali metal carbonate and the alkali metal bicarbonate.

8 more elements

An apparatus for carbon capture coupled hydrogen production, comprising:

a low-concentration CO2 absorption unit, having an inlet for a solution of an alkali metal hydroxide, an inlet for a first to-be-captured raw material that comprises low-concentration CO2, an outlet for a first portion of a low-concentration CO2 absorption solution, an outlet for a second portion of the low-concentration CO2 absorption solution, and an outlet for a first exhaust gas, wherein the low-concentration CO2 absorption unit is configured to capture low-concentration CO2 by using the solution of the alkali metal hydroxide, to obtain the low-concentration CO2 absorption solution;
and the low-concentration CO2 absorption solution comprises an alkali metal carbonate and the alkali metal hydroxide;
a high-concentration CO2 absorption unit, having an inlet for the first portion of the low-concentration CO2 absorption solution, an inlet for a second to-be-captured raw material that comprises high-concentration CO2, an outlet for a high-concentration CO2 absorption solution, and an outlet for a second exhaust gas, wherein the inlet for the first portion of the low-concentration CO2 absorption solution is connected to the outlet for the first portion of the low-concentration CO2 absorption solution;
the high-concentration CO2 absorption unit is configured to capture high-concentration CO2 by using the first portion of the low-concentration CO2 absorption solution, to obtain the high-concentration CO2 absorption solution;
and the high-concentration CO2 absorption solution comprises the alkali metal carbonate and an alkali metal bicarbonate;
and
an electrolysis unit, having an inlet for a catholyte solution, a non-ionic diaphragm, an inlet for an anolyte solution, an outlet for a cathodic discharge liquid, an outlet for an anodic discharge liquid, an outlet for H2, and an outlet for a mixed gas of O2 and CO2, wherein the inlet for the catholyte solution is connected to the outlet for the second portion of the low-concentration CO2 absorption solution;
the outlet for the catholyte solution is connected to the inlet for the solution of the alkali metal hydroxide;
the inlet for the anolyte solution is connected to the outlet for the high-concentration CO2 absorption solution;
and the electrolysis unit is configured to electrolyze the second portion of the low-concentration CO2 absorption solution and the high-concentration CO2 absorption solution, to obtain H2 and the cathodic discharge liquid at an electrolytic cathode, and obtain O2, CO2, and the anodic discharge liquid at an electrolytic anode, wherein the cathodic discharge liquid comprises the alkali metal carbonate and the alkali metal hydroxide;
and the anodic discharge liquid comprises the alkali metal carbonate and the alkali metal bicarbonate.

8 more elements

Dependencies are inferred from the claim text.