Alkali enrichment mediated CO
Methods of sequestering CO 2 from a gaseous source of CO 2 are provided. Aspects of the methods include employing an alkali enrichment protocol, such as a membrane mediated alkali enrichment protocol, in a CO 2 sequestration protocol. Also provided are systems for practicing the methods.
1. A method for sequestering CO 2 from a gaseous source of CO 2 , the method comprising:
a) subjecting an initial liquid to a membrane mediated alkali enrichment protocol to produce an enhanced alkalinity liquid, wherein the membrane mediated alkali enrichment protocol comprises contacting the initial liquid with a first side of a membrane and contacting a second liquid with an opposite side of the membrane, wherein charges in the initial liquid and the second liquid are balanced by flow of H + ions or OH − ions through the membrane and the initial liquid becomes the enhanced alkalinity liquid; and
b) employing the enhanced alkalinity liquid in a CO 2 sequestration protocol to sequester CO 2 .
2. The method according to claim 1 , wherein the membrane is a cationic membrane and charges in the initial liquid and the second liquid are balanced by flow of H + ions through the cationic membrane.
3. The method according to claim 1 , wherein the membrane is an anionic membrane and charges in the initial liquid and the second liquid are balanced by flow of OH − ions through the anionic membrane.
4. The method according to claim 1 , wherein alkali enrichment protocol comprises an osmotic pressure mediated protocol.
5. The method according to claim 1 , wherein the initial liquid is selected from the group consisting of freshwater, seawater, brine water, produced water and waste water.
6. The method according to claim 1 , wherein the method comprises contacting the enhanced alkalinity liquid with the gaseous source of CO 2 under conditions sufficient to produce an LCP containing liquid.
7. The method according to claim 1 , wherein the method comprises producing the initial liquid by contacting a source liquid with the gaseous source of CO 2 .
8. The method according to claim 1 , wherein the gaseous source of CO 2 is a multi-component gaseous stream.
9. The method according to claim 8 , wherein the gaseous source of CO 2 is a flue gas.
10. The method according to claim 7 , wherein the gaseous source of CO 2 is contacted with a liquid under conditions such that CO 2 is selectively absorbed by the source liquid.
11. The method according to claim 7 , wherein the gaseous source of CO 2 is contacted with the source liquid using a hollow fiber membrane contactor.
12. The method according to claim 1 , wherein the CO 2 sequestration protocol comprises producing a carbonate from a LCP that comprises dissolved inorganic carbon (DIC) obtained from the gaseous source of CO 2 .
13. The method according to claim 12 , wherein the carbonate is produced by introducing a cation source into an LCP containing liquid under conditions sufficient to produce the carbonate.
14. The method according to claim 13 , wherein the cation source is a source of divalent cations.
15. The method according to claim 14 , wherein the divalent cations comprise 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 14 , wherein the divalent cation source is introduced into a flowing LCP containing liquid under conditions sufficient such that a non-slurry solid phase CO 2 sequestering carbonate material is produced in the flowing LCP containing liquid.
18. The method according to claim 14 , wherein the divalent cation source is introduced into an LCP containing liquid under conditions sufficient such that a slurry CO 2 sequestering carbonate material is produced from the LCP containing liquid.
19. The method according to claim 1 , wherein the method is a continuous process.