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 to produce a bicarbonate rich product; and
combining the bicarbonate rich product or a component thereof with a cation source to produce a solid carbonate composition without the use of an additional alkalinity source;
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 CO 2 containing gas is contacted with the aqueous medium in the presence of an LCP promoter.
5. The method according to claim 1 , wherein the reaction is a continuous reaction.
6. The method according to claim 1 , wherein the reaction is a batch reaction.
7. The method according to claim 1 , wherein the method is a method of sequestering CO 2 .
8. The method according to claim 1 , wherein the CO 2 containing gas is obtained from an industrial plant.
9. The method according to claim 1 , wherein the aqueous medium comprises an amine.
10. The method according to claim 1 , wherein the bicarbonate rich product comprises droplets of a liquid condensed phase (LCP) in a bulk liquid.
11. The method according to claim 10 , wherein the concentration of bicarbonate anions in the LCP droplets is 10,000 ppm or higher.
12. 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.
13. The method according to claim 12 , wherein the catalyst is an enzyme.
14. The method according to claim 1 , wherein the cation source is a source of divalent cations.
15. The method according to claim 14 , wherein the divalent cations are alkaline earth metal cations.
16. The method according to claim 15 , wherein the divalent alkaline earth metal cations are selected from the group consisting of Ca 2+ and Mg 2+ , and combinations thereof.
17. The method according to claim 1 , wherein the method further comprises producing a commodity from the solid carbonate composition.
18. The method according to claim 17 , wherein the commodity is a building material.
19. The method according to claim 18 , wherein the building material is a cement or supplemental cementitious material.
20. A method of removing carbon dioxide (CO 2 ) from a CO 2 containing gas obtained from an industrial plant, the method comprising:
contacting the gas obtained from the industrial plant with a bicarbonate buffered aqueous medium having a pH ranging from 8 to 10 to produce a bicarbonate rich product comprising droplets of a liquid condensed phase (LCP) in a bulk liquid;
combining the bicarbonate rich product or a component thereof with a cation source to produce a solid carbonate composition without the use of an additional alkalinity source; and
producing a commodity from the solid carbonate composition;
to remove CO 2 from the CO 2 containing gas.
21. The method according to claim 20 , wherein the industrial plant is a power plant.
22. A method of removing carbon dioxide (CO 2 ) from a CO 2 containing gas obtained from an industrial plant, the method comprising:
contacting the gas obtained from the industrial plant with a bicarbonate buffered aqueous medium having a pH ranging from 8 to 10 to produce a bicarbonate rich product comprising droplets of a liquid condensed phase (LCP) in a bulk liquid;
combining the bicarbonate rich product or a component thereof with a cation source to produce a solid carbonate composition without the use of an additional alkalinity source; and
producing an aggregate from the solid carbonate composition;
to remove CO 2 from the CO 2 containing gas and produce purified CO 2 from the gaseous stream.