Integration of thermochemical water splitting with CO2 direct air capture

Patent metadata

Field	Value
Publication number	US-11634322-B2
Application number	US-202016837450-A
Country	US
Kind code	B2
Filing date	Apr 1, 2020
Priority date	Apr 3, 2019
Publication date	Apr 25, 2023
Grant date	Apr 25, 2023

Abstract

The present disclosure is directed to the integration of direct air capture of carbon dioxide with thermochemical water splitting, the latter optionally driven by solar energy. The disclosure is also directed to a process comprising extracting carbon dioxide from an air stream by contacting the air-stream with an alkali metal ion-transition metal oxide of empirical formula AxMO2 (0.1<x≤1), where A represents the alkali metal ion comprising sodium ion, potassium ion, or a combination thereof and M comprises iron, manganese, or a combination thereof to form a transition metal composition comprising an oxidized ion extracted-transition metal oxide.

First claim

What is claimed:

1. A process comprising extracting carbon dioxide from an air stream by contacting the air stream with a composition comprising an alkali metal ion-transition metal oxide of empirical formula A x MO 2 (0.1<x≤1) to form a transition metal composition comprising an oxidized ion extracted-transition metal oxide, where A represents the alkali metal ion comprising sodium ion, potassium ion, or a combination thereof and M comprises iron, manganese, or a combination thereof.

2. The process of claim 1 , wherein the contacting is done in the presence of water or steam.

3. The process of claim 1 , wherein the contacting is done at a temperature in a range of from about 60° C. to 250° C.

4. The process of claim 1 , wherein the air stream is atmospheric air.

5. The process of claim 4 , wherein the atmospheric air has a CO 2 content in a range of from 150 ppm to 500 ppm by weight.

6. The process of claim 1 , wherein the air stream containing the carbon dioxide is delivered to the alkali metal ion-transition metal oxide using a solar updraft air tower.

7. The process of claim 1 , wherein the alkali metal ion-transition metal oxide is generated in a second process of thermochemically forming H 2 , O 2 , or both H 2 and O 2 , each separately, from water, said second process comprising:
(a) contacting a composition comprising a spinel-type transition metal oxide of formula M 3 O 4 with an alkali metal carbonate, bicarbonate, or mixture thereof in the presence of H 2 O at a first temperature in a range of from 450° C. to 1000° C. to form H 2 , CO 2 , and the alkali metal ion-transition metal oxide, said alkali metal ion-transition metal oxide having an average transition metal oxidation state that is higher than the average oxidation state of the transition metal in the spinel-type transition metal oxide;
(b) hydrolytically extracting at least a portion of alkali metal ions from the alkali metal ion-transition metal oxide by the reaction with CO 2 , and liquid H 2 O at a second temperature in a range of from 60° C. to 250° C. to form a transition metal composition comprising an oxidized ion extracted-transition metal oxide in which the average oxidation state of the transition metal in the oxidized ion extracted-transition metal oxide is the same as the average oxidation state of the transition metal in the alkali metal ion-transition metal oxide; and
(c) thermochemically reducing the transition metal composition of step (b) at a third temperature in a range of from 450° C. to 1150° C., with the associated formation of O 2 :
wherein the transition metal, M, comprises iron, manganese, or a combination thereof, and the corresponding spinel-type transition metal oxide comprises Fe 3 O 4 , Mn 3 O 4 , or a solid solution or physical mixture thereof; and
wherein the alkali metal ion comprises sodium ion, potassium ion, or a combination thereof.

8. The process of claim 7 , wherein the H 2 and CO 2 generated by the second process is captured.

9. The process of claim 7 , wherein the H 2 and CO 2 generated by the second process is captured and converted to (a) syngas via the reverse water gas shift reaction or (b) to methanol by hydrogenation of the CO 2 or (c) to higher hydrocarbons by upgrading the CO 2 /H 2 stream.

10. The process of claim 7 , where energy for the process or the second process is derived from solar energy, preferably via solar concentrator.

11. The process of claim 7 , wherein the second process is operated one or more times a day or continuously.

12. The process of claim 7 , wherein the step (a) of contacting the composition comprising a spinel-type transition metal oxide of formula M 3 O 4 with an alkali metal carbonate, bicarbonate, or mixture thereof is done stepwise first in the absence and then in the presence of H 2 O.

13. The process of claim 7 , wherein the carbonate, bicarbonate, or mixture thereof comprises a carbonate.

14. The process of claim 7 , wherein at least one of the first and third temperatures is in a range of from 750° C. to 850° C.

15. The process of claim 7 , wherein the second temperature is (1) in a range of from about 60° C. to about 95° C., at ambient atmospheric pressure or (2) in a range of from about 100° C. to about 250° C., wherein the CO 2 is present at a partial pressure in a range of from about 1 bar to about 25 bar.

16. The process of claim 7 , wherein the third temperature is in a range of from 550° C. to 1150° C.

17. The process of claim 7 , wherein the thermochemical reduction of the oxidized-transition metal oxide results in a regeneration of the spinel-type transition metal oxide of (a).

18. The process of claim 7 , wherein the transition metal comprises manganese; the carbonate, bicarbonate, or mixture thereof comprises a carbonate; and the alkali metal ion comprises sodium ion.

19. The process of claim 7 , wherein the alkali metal ion is Na + and the alkali metal ion transition metal oxide comprises a composition having an empirical formula NaMnO 2 .

20. The process of claim 7 , wherein the transition metal composition of step (b) comprises a protonic birnessite, and the thermochemical reduction of this product is done at the third temperature in a range of from 750° C. to 850° C.

21. The process of claim 7 , said method comprising:
(a) contacting a composition comprising a spinel-type Mn 3 O 4 with sodium carbonate in the presence of H 2 O at a first temperature in a range of from about 550° C. to about 900° C., to form H 2 , CO 2 , and a sodium birnessite-type A x MnO 2 (0<x<1), the sodium birnessite-type manganese dioxide having an average transition metal oxidation state that is higher than the average oxidation state of the transition metal in the spinel-type Mn 3 O 4 ;
(b) hydrolytically extracting at least a portion of sodium cations from the sodium birnessite-type manganese dioxide by the reaction with CO 2 and liquid H 2 O at a second temperature in a range of (1) from about 70° C. to about 90° C. at ambient pressure or (2) from about 140° C. to about 200° C. at a partial pressure of CO 2 in a range of from about 3 bar to about 20 bar to form a transition metal composition comprising an protonic birnessite in which the average oxidation state of the transition metal in the protonic birnessite is the same as the average oxidation state of the transition metal in the sodium birnessite-type manganese dioxide; and
(c) thermochemically reducing the transition metal composition of step (b) at a third temperature in a range of from about 550° C. to about 900° C., preferably about 850° C., with the associated formation of O 2 .

22. The process of claim 7 , wherein the transition metal comprises iron; the carbonate, bicarbonate, or mixture thereof comprises a carbonate; and the alkali metal ion comprises sodium ion, potassium ion, or a combination thereof.

23. The process of claim 7 , wherein the alkali metal ion-transition metal oxide is NaFeO 2 or KFeO 2 , formed by the reactions between Fe 3 O 4 and sodium carbonate or between Fe 3 O 4 and potassium carbonate, respectively.

24. The process of claim 7 , wherein the alkali metal ion is Na + or K + or a combination thereof, and the alkali metal ion-transition metal oxide comprises a composition having a stoichiometry of NaFeO 2 or KFeO 2 .

25. The process of claim 1 , wherein the alkali metal ion-stabilized oxidized-transition metal oxide comprises a composition having an empirical formula of NaMn

Assignees

• California Inst Of Techn
• Univ Delaware

Inventors

• Davis Mark E
• Xu Bingjun
• Brady Casper O

Classifications

• C01B3/10

  by reaction of water vapour with metals · CPC title

• B01D2257/504

  Carbon dioxide · CPC title

• B01D2251/602

  Oxides · CPC title

• Y02P20/151

  Reduction of greenhouse gas [GHG] emissions, e.g. CO2 · CPC title

• B01D2258/06

  Polluted air · CPC title