CO 2 mineralization in produced and industrial effluent water by pH-swing carbonation
Effluent water is combined with carbon dioxide sourced from a carbon dioxide-containing emission stream to produce a reaction solution. The pH of the reaction solution is controlled to induce precipitation of a carbonate salt from the reaction solution.
1. A method comprising:
combining effluent water with carbon dioxide sourced from a carbon dioxide-containing emission stream to produce a reaction solution; and
controlling the pH of the reaction solution with a regenerable, heterogeneous pH buffer agent to induce precipitation of a carbonate salt from the reaction solution;
wherein the carbon dioxide-containing emission stream is a flue gas stream; and
the regenerable heterogeneous pH buffer agent is a polymer-supported buffer agent or a zeolite that supports cation exchange reactions.
2. The method of claim 1 , wherein controlling the pH includes increasing the pH of the reaction solution.
3. The method of claim 1 , wherein controlling the pH includes adjusting the pH of the reaction solution to 6 or greater.
4. The method of claim 1 , wherein controlling the pH includes adjusting the pH of the reaction solution to 6.5 or greater.
5. The method of claim 1 , further comprising, subsequent to the precipitation of the carbonate salt, recovering the regenerable, heterogeneous pH buffer agent by filtration.
6. The method of claim 1 , wherein the flue gas stream comprises from about 1% CO 2 to about 100% CO 2 .