ALKALINE CATION ENRICHMENT AND WATER ELECTROLYSIS TO PROVIDE CO2 MINERALIZATION AND GLOBAL-SCALE CARBON MANAGEMENT
Provided herein are methods of removing carbon dioxide from an aqueous stream or gaseous stream by: contacting the gaseous stream comprising carbon dioxide, when present, with an aqueous solution comprising ions capable of forming an insoluble carbonate salt; contacting the aqueous solution comprising carbon dioxide with an electroactive mesh that induces its alkalinization thereby forcing the precipitation of a carbonate solid from the solution and thereby the removal of dissolved inorganic carbon by electrolysis; and removing the precipitated carbonate solids from the solution, or the surface of the mesh where they may deposit. Also provided herein are flow-through electrolytic reactors comprising an intake device in fluid connection with a rotating cylinder comprising an electroactive mesh, and a scraping device and/or liquid-spray based device for separating a solid from the mesh surface.
1 . A method of removing carbon dioxide from a fluid comprising carbon dioxide by:
contacting the fluid comprising the carbon dioxide with a first aqueous solution comprising calcium and/or magnesium cations, thereby forming a second aqueous solution comprising the carbon dioxide and the calcium and/or magnesium; and
performing water electrolysis on the second aqueous solution by contacting the second aqueous solution with an electroactive mesh, thereby inducing alkalinization of the second aqueous solution and precipitation of calcium carbonate solids and/or magnesium carbonate solids from the second aqueous solution.
2 . The method of claim 1 , wherein the fluid is a gaseous fluid.
3 . The method of claim 1 , wherein the gaseous fluid comprises between 0.04 to 100 vol. % CO 2 .
4 . The method of claim 1 , wherein the gaseous fluid is atmospheric air.
5 . The method of claim 1 , wherein the gaseous fluid is flue gas emitted from a natural gas-fired power plant, a coal-fired power plant, an iron mill, a steel mill, a cement plant, an ethanol plant, or a chemical manufacturing plant.
6 . The method of claim 1 , wherein the first aqueous solution contains an amount of dissolved carbon dioxide that is in equilibrium with the gaseous fluid.
7 . The method of claim 2 , wherein the first aqueous solution is in thermal equilibrium with the gaseous fluid.
8 . The method of claim 2 , wherein the first aqueous solution is not in thermal equilibrium with the gaseous fluid.
9 . (canceled)
10 . The method of claim 1 , wherein the aqueous solution further comprises an additional cation capable of forming an insoluble carbonate salt selected from Ba, Sr, Fe, Zn, Pb, Cd, Mn, Ni, Co, Cu, Al, and any combination thereof.
11 . (canceled)
12 . The method of claim 1 , wherein the first aqueous solution has a concentration of NaCl of about 30,000 ppm or more.
13 . The method of claim 1 , wherein the first aqueous solution comprises seawater.
14 . (canceled)
15 . The method of claim 1 , wherein the method utilizes an end-to-end energy intensity of about 2.5 MWh or less per ton of carbon dioxide mineralized.
16 . (canceled)
17 . The method of claim 1 , wherein the electroactive mesh produces an increased alkaline condition, in situ, in the second aqueous solution up to a distance in a range of about 2 to 20000 μm from a surface of the electroactive mesh.
18 . The method of claim 17 , wherein the alkalinized condition is a pH of 9 or greater.
19 . (canceled)
20 . The method of claim 1 , wherein the electroactive mesh comprises stainless steel, titanium oxide, carbon nanotubes, polymers, and/or graphite, or other hybrid compositions of these materials.
21 . The method of claim 1 , wherein the electroactive mesh comprises pores having a diameter in the range of about 0.1 μm to about 10000 μm.
22 - 33 . (canceled)
34 . The method of claim 1 , wherein contacting the fluid comprising carbon dioxide with the first aqueous solution comprises continuously equilibrating the first aqueous solution with the fluid comprising carbon dioxide.
35 . The method of claim 1 , wherein contacting the second aqueous solution with the mesh electrode comprises passing the second aqueous solution through the pores of the mesh electrode.
36 . The method of claim 1 , wherein the mesh electrode is a planar mesh electrode.
37 . The method of claim 1 , further comprising removing the precipitated calcium and/or magnesium carbonate solids from the solution or a surface of the mesh where they may deposit.