Process for sequestering carbon dioxide and sulfur dioxide

• US 20050002847A1
• Filed: 04/29/2004
• Published: 01/06/2005
• Est. Priority Date: 05/02/2003
• Status: Active Grant

• Current Assignee: Penn State Research Foundation
• Original Assignee: Penn State Research Foundation
• Inventors: Zhang, Yinzhi, Kuchta, Matthew E., Fauth, Dan J., Maroto-Valer, M. Mercedes, Andresen, John M.
• Granted Patent: US 7,604,787 B2
• Time in Patent Office: Days
• US Class Current: 423/432
• CPC Class Codes: B01D 2253/106 Silica or silicates
• CPC Class Codes: B01D 2257/302 Sulfur oxides
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: B01D 2259/80 Employing electric, magnetic, electromagnetic or wave energy, or particle radiation
• CPC Class Codes: B01D 53/62 Carbon oxides
• CPC Class Codes: C01B 32/60 Preparation of carbonates or bicarbonates in general of percarbonates C01B15/10; of specific carbonates or bicarbonates according to the cation C01B-C01G
• CPC Class Codes: C01B 33/193 of aqueous solutions of silicates
• CPC Class Codes: C01F 5/24 Magnesium carbonates
• CPC Class Codes: Y02C 20/40 of CO2
• CPC Class Codes: Y02P 20/151 Reduction of greenhouse gas [GHG] emissions, e.g. CO2

Abstract

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.

Claims

1. A process for sequestering carbon dioxide, comprising:

a) reacting a silicate based material with an acid to form a suspension; 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 is a serpentine material according to the formula X_nSi₂O₅(OH)₄;

wherein X is selected from the group consisting of Mg, Ca, Fe²⁺, Fe³⁺, Ni, Al, Zn, and Mn;

n is 2 or 3, said serpentine material being a heterogeneous mixture of primarily magnesium hydroxide and silica.

3. The process of claim 1, wherein the silicate based material is selected from the group consisting of olivine, serpentine, wollastonite, magnesium silicate, and calcium silicate.

4. The process of claim 1, wherein the acid reacts with the silicate based material for a period of time for the silica to achieve a surface area ranging from about 15 to over 330 m²/g.

5. The process of claim 1, wherein the acid is selected from the group consisting of sulfuric acid, nitric acid, phosphoric acid, and acetic 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. The process of claim 1 further including the additional steps, directly after the silicate based material is reacted with the acid, of reacting the suspension with calcium nitrate (Ca(NO₃)₂) and then adding calcium hydroxide (Ca(OH)₂) to precipitate the metal.

9. The process of claim 1, wherein the silica has a surface area of about 100 to over 330 m²/g after the addition of the acid.

10. The process of claim 1, wherein the process is conducted at temperature ranges from about 15°

C. to about 150°

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 below 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 (caustic wastes) and high pH aqueous streams (ammonia hydroxide streams). The pH range of the bases includes from 7 to 14.

14. A process for sequestering carbon dioxide, comprising:

a) reacting a silicate based material with sulfuric acid to form a suspension;

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, serpentine, and calcium silicate.

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 below 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 for a period of time for the silica to achieve a surface area ranging from about 100 to over 330 m²/g.

20. A process for sequestering carbon dioxide, comprising:

a) reacting a silicate based material with sulfuric acid, to form a suspension;

b) mixing calcium nitrate Ca(NO₃)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 possibly 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.