Process for sequestering carbon dioxide and sulfur dioxide
A process for sequestering carbon dioxide, which includes reacting a silicate based material with an acid to form a suspension, and combining the suspension with carbon dioxide to create active carbonation of the silicate-based material, and thereafter producing a metal salt, silica and regenerating the acid in the liquid phase of the suspension.
1. A process for sequestering carbon dioxide, comprising:
a) reacting a silicate based material with an acid to form a suspension, wherein the acid is selected from the group consisting of sulfuric acid and nitric acid, and wherein the silicate base material comprises magnesium; and
b) combining said suspension with carbon dioxide, producing a metal salt, silica and regenerating said acid in solution.
2. The process in claim 1 , wherein the silicate based material further comprises a serpentine material according to the formula X n Si 2 O 5 (OH) 4 ; wherein X is selected from the group consisting of Mg, Ca, Fe 2+ , Fe 3+ , Ni, Al, Zn, and Mn; n is 2 or 3, said serpentine material being a mixture of hydroxide and silica.
3. The process of claim 1 , wherein the silicate based material is selected from the group consisting of olivine, serpentine, wollastonite, and magnesium silicate.
4. The process of claim 1 , wherein the acid reacts with the silicate based material, wherein the silica achieves a BET surface area greater than 122 m 2 /g.
5. The process of claim 1 , wherein the acid is sulfuric acid.
6. The process of claim 1 , further including an additional step of reacting the suspension with a base after the silicate based material is reacted with the acid.
7. The process of claim 6 , wherein the base is sodium hydroxide.
8. A process for sequestering carbon dioxide, comprising:
a) reacting a silicate based material with an acid to form a suspension, wherein the acid is selected from the group consisting of sulfuric acid and nitric acid;
b) combining said suspension with carbon dioxide, producing a metal salt, silica and regenerating said acid in solution; and
c) directly after the silicate based material is reacted with the acid, reacting the suspension with calcium nitrate (Ca(NO 3 ) 2 ) and then adding calcium hydroxide (Ca(OH) 2 ) to precipitate the metal, wherein the silicate based material comprises a metal selected from the group consisting of Mg, Fe 2+ , Fe 3+ , Ni, Al, Zn, and Mn.
9. The process of claim 1 , wherein the silica has a BET surface area of about 100 to about 330 m 2 /g after the addition of the acid.
10. The process of claim 1 , wherein the reacting step is conducted at temperature ranges from about 15° C. to about 50° C.
11. The process of claim 1 , wherein the process is conducted at pressure ranges from about 14 psig (ambient conditions) to about 1850 psig.
12. A process for sequestering carbon dioxide as in claim 1 , wherein said acid is protic, diprotic or triprotic and pH from about 6.25 to about 3.
13. A process for sequestering carbon dioxide as in claim 6 , wherein said base includes both alkaline and alkaline earth hydroxides, high pH by-products and high pH aqueous streams, and said base has a pH in the range between 7 and 14.
14. A process for sequestering carbon dioxide, comprising:
a) reacting a silicate based material with sulfuric acid to form a suspension, wherein the silicate based material comprises magnesium;
b) reacting the suspension with a base to precipitate a metal hydroxide; and
c) combining said suspension with carbon dioxide, producing a metal carbonate and regenerating said sulfuric acid.
15. The process of claim 14 , wherein the silicate based material is selected from the group consisting of olivine and serpentine.
16. The process of claim 14 , wherein the form of the carbon dioxide is selected from the group consisting of a gas, a fluid, a subcritical fluid, a supercritical fluid, and a critical fluid.
17. The process of claim 14 , wherein said sulfuric acid has an initial concentration ranging from about 6 M to about 1 M.
18. The process of claim 14 , wherein the base is sodium hydroxide.
19. The process of claim 14 , wherein the sulfuric acid reacts with the silicate based material, wherein the silica achieves a BET surface area ranging from about 100 to about 330 m 2 /g.
20. A process for sequestering carbon dioxide, comprising:
a) reacting a silicate based material with sulfuric acid, to form a suspension, wherein the silicate based material comprises a metal selected from the group consisting of Mg, Fe 2+ , Fe 3+ , Ni, Al, Zn, and Mn;
b) mixing calcium nitrate Ca(NO 3 ) 2 with said suspension;
c) precipitating the metal using calcium hydroxide Ca(OH) 2 ; and
combining the suspension with carbon dioxide to sequester the carbon dioxide, producing a metal salt and silica and regenerating the sulfuric acid.
21. The process of claim 20 , wherein the silicate based material is selected from the group consisting of olivine, serpentine, and calcium silicate.
22. The process of claim 4 , wherein the BET surface area is equal to or greater than about 147 m 2 /g.
23. The process of claim 14 , wherein the sulfuric acid reacts with the silicate based material, wherein the silica achieves a BET surface area equal to or greater than about 147 m 2 /g.
24. The process of claim 23 , wherein the BET surface area is equal to or greater than about 330 m 2 /g.
25. A process for sequestering carbon dioxide, comprising:
a) reacting a silicate based material with an acid to form a suspension, wherein the acid is selected from the group consisting of sulfuric acid and nitric acid, wherein the silicate base material comprises magnesium, and wherein more than about 70% of the magnesium is dissolved from the silicate based material; and
b) combining said suspension with carbon dioxide, producing a metal salt, silica and regenerating said acid in solution.