Carbon sequestration methods and systems, and compositions produced thereby
Aspects of the invention include methods of removing carbon dioxide (CO 2 ) from a CO 2 containing gas. In some instances, the methods include contacting CO 2 containing gas with a bicarbonate buffered aqueous medium under conditions sufficient to produce a bicarbonate rich product. Where desired, the resultant bicarbonate rich product or a component thereof may then be stored or further processed, e.g., combined with a divalent alkaline earth metal cation, under conditions sufficient to produce a solid carbonate composition. Aspects of the invention further include systems for practicing the methods, as well as products produced by the methods.
1. A method of removing carbon dioxide (CO 2 ) from a CO 2 containing gas, the method comprising:
contacting the gas with a bicarbonate buffered aqueous medium under conditions sufficient to produce a bicarbonate rich product;
combining the bicarbonate rich product or a component thereof with a cation source under conditions sufficient to produce a solid carbonate composition and a CO 2 gaseous product; and
actively removing the CO 2 gaseous product and thereby enhancing the production of the solid carbonate composition;
to remove CO 2 from the CO 2 containing gas.
2. The method according to claim 1 , wherein the bicarbonate buffered aqueous medium has a pH ranging from 8 to 10.
3. The method according to claim 1 , wherein the pCO 2 of the CO 2 containing gas in contact with bicarbonate buffered aqueous medium is 10 4 Pa or higher.
4. The method according to claim 1 , wherein the bicarbonate rich product comprises droplets of a liquid condensed phase (LCP) in a bulk liquid.
5. The method according to claim 1 , wherein the CO 2 containing gas is contacted with the aqueous medium in the presence of a catalyst that mediates the conversion of CO 2 to bicarbonate.
6. The method according to claim 5 , wherein the catalyst is an enzyme.
7. The method according to claim 6 , wherein the enzyme is a carbonic anhydrase.
8. The method according to claim 5 , wherein the catalyst is a synthetic catalyst.
9. The method according to claim 5 , wherein the catalyst is a metal colloid particle catalyst.
10. The method according to claim 1 , wherein the aqueous medium further comprises an alkali metal cation.
11. The method according to claim 10 , wherein the alkali metal cation is Na + .
12. The method according to claim 1 , wherein the building material is an aggregate.
13. The method according to claim 1 , wherein the method is a method of sequestering CO 2 .
14. The method according to claim 1 , wherein the CO 2 containing gas is obtained from an industrial plant.
15. The method according to claim 1 , wherein the CO 2 gaseous product is purified.
16. The method according to claim 1 , wherein actively removing the CO 2 gaseous product comprises the use of a catalyst.
17. The method according to claim 1 , wherein actively removing the CO 2 gaseous product comprises purging the CO 2 gaseous product using N 2 gas.
18. A system for removing CO 2 from a CO 2 containing gas, the system comprising:
a source of the CO 2 containing gas;
a source of bicarbonate buffered aqueous medium; and
a reactor configured to contact the CO 2 containing gas with the aqueous medium under conditions sufficient to produce a bicarbonate rich product and produce a CO 2 gaseous product, wherein the system is configured to produce a solid carbonate composition from the bicarbonate rich product and actively remove the CO 2 gaseous product from the system and thereby enhancing the production of the solid carbonate composition.
19. The system according to claim 18 , wherein the reactor comprises a catalyst that mediates the conversion of CO 2 to bicarbonate.