Electrochemical process for gas separation
The present disclosure generally relates to apparatuses, systems, and methods for separating a target species (e.g., CO 2 ) from a gas mixture (e.g., gas stream) via an electrochemical process.
1. An electrochemical cell comprising:
a porous first electrode for treating a gas stream comprising a target species, the first electrode comprising a composite comprising a porous matrix of a gas permeable material mixed with an immobilized electroactive species;
a second electrode having an opposite polarity of the first electrode;
a separator positioned between the first electrode and the second electrode; and
a conductive liquid, at least a portion of which is associated with the separator and the first electrode;
wherein:
the electroactive species is capable of bonding with the target species when the electroactive species is in a first oxidation state and releasing the target species when the electroactive species is in a second oxidation state;
the target species comprises carbon dioxide, sulfur dioxide, a borane, or a combination thereof; and
the electroactive species comprises a polymeric quinone, a polymeric thiolate, and/or a polymeric bipyridine.
2. The electrochemical cell of claim 1 , wherein the first electrode is a negative electrode, the second electrode is a positive electrode, the first oxidation state is a reduced state and the second oxidation state is an oxidized state.
3. The electrochemical cell of claim 1 , wherein the electroactive species comprises a polymeric quinone.
4. The electrochemical cell of claim 1 , wherein the target species comprises carbon dioxide.
5. The electrochemical cell of claim 1 , wherein the electrode is at least 70% porous.
6. The electrochemical cell of claim 2 , wherein the electroactive species comprises a polymeric quinone.
7. The electrochemical cell of claim 6 , wherein the aprotic acidic gas is target species comprises carbon dioxide.
8. The electrochemical cell of claim 1 , wherein the composite has an absorption capacity for the target species of between 0.01 and 0.1 mol per m 2.
9. The electrochemical cell of claim 5 , wherein the first electrode is a negative electrode, the second electrode is a positive electrode, the first oxidation state is a reduced state, and the second oxidation state is an oxidized state.
10. The electrochemical cell of claim 9 , wherein the electroactive species comprises a polymeric quinone.
11. The electrochemical cell of claim 9 , wherein the target species comprises carbon dioxide.
12. The electrochemical cell of claim 1 , wherein the first electrode is at least 20% porous.
13. The electrochemical cell of claim 1 , wherein a portion of the conductive liquid is associated with the separator and the second electrode.
14. A porous electrode for treating a gas stream comprising a target species, the electrode comprising a composite comprising a porous matrix of a gas permeable material mixed with an immobilized electroactive species;
wherein:
the composite has an absorption capacity for the target species of greater than or equal to 0.01 mol per m 2 ;
the electroactive species is capable of bonding with the target species when the electroactive species is in a first oxidation state and releasing the target species when the electroactive species is in a second oxidation state;
the target species comprises carbon dioxide, sulfur dioxide, a borane, or a combination thereof; and
the electroactive species comprises a polymeric quinone, a polymeric thiolate, and/or a polymeric bipyridine.
15. The electrode of claim 14 , wherein the target species comprises carbon dioxide.
16. The electrode of claim 15 , wherein the composite has an absorption capacity for the target species of between 0.01 and 0.1 mol per m 2 .
17. The electrode of claim 14 , wherein the electrode is at least 20% porous.
18. The electrode of claim 14 , wherein the electroactive species comprises a polymeric quinone.
19. The electrode of claim 15 , wherein the electroactive species comprises a polymeric quinone.
20. The electrode of claim 16 , wherein the electroactive species comprises a polymeric quinone.