METHOD AND APPARATUS FOR THE REMOVAL OF CARBON DIOXIDE FROM A GAS STREAM

• US 20090104098A1
• Filed: 10/19/2007
• Published: 04/23/2009
• Est. Priority Date: 10/19/2007
• Status: Active Grant

• Current Assignee: FluGen, Inc.
• Original Assignee: FluGen, Inc.
• Inventors: Singh, Uday
• Granted Patent: US 7,964,170 B2
• Time in Patent Office: Days
• US Class Current: 423/224
• CPC Class Codes: B01D 2251/304 of sodium
• CPC Class Codes: B01D 2251/404 of calcium
• CPC Class Codes: B01D 2251/604 Hydroxides
• CPC Class Codes: B01D 2251/606 Carbonates
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: B01D 53/1493 Selection of liquid materials for use as absorbents
• CPC Class Codes: B01D 53/501 by treating the gases with a solution or a suspension of an alkali or earth-alkali or ammonium compound
• CPC Class Codes: B01D 53/62 Carbon oxides
• CPC Class Codes: B01D 53/864 Removing carbon monoxide or hydrocarbons
• CPC Class Codes: F01N 3/01 by means of electric or electrostatic separators
• CPC Class Codes: Y02A 50/20 Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
• CPC Class Codes: Y02C 20/40 of CO2

Abstract

The invention provides methods and apparatuses for removing carbon dioxide from a gas stream. In particular, the invention provides methods and apparatuses for absorbing carbon dioxide from a coal-fired boiler flue gas stream using an absorbing solution and for regeneration of an alkaline component used in the absorbing solution. In one embodiment, the invention provides a method for removing carbon dioxide from a gas stream by contacting a gas stream containing carbon dioxide with an alkaline liquid stream; absorbing at least a portion of the carbon dioxide into the alkaline liquid stream to produce absorbed carbon dioxide; and catalyzing a reaction of the: absorbed carbon dioxide to a form of carbonate.

Claims

1. A method for removing at least a portion of carbon dioxide in a gas stream, comprising:

contacting a gas stream comprising carbon dioxide with an alkaline liquid stream;

absorbing at least a portion of the carbon dioxide into the alkaline liquid stream to produce absorbed carbon dioxide; and

catalyzing a reaction of the absorbed carbon dioxide to a form of carbonate.

2. The method of claim 1, wherein the gas stream comprises a flue gas stream from a coal-fired boiler, and the alkaline liquid stream comprises sodium hydroxide.

3. The method of claim 1, wherein the gas stream comprises a flue gas stream from a coal-fired boiler, and the alkaline liquid stream comprises calcium hydroxide.

4. The method of claim 1, wherein said catalyzing comprises catalyzing the reaction of the absorbed carbon dioxide to the form of carbonate with a catalyst and wherein the alkaline liquid stream comprises the catalyst.

5. The method of claim 4, wherein the catalyst comprises a monosaccharide.

6. The method of claim 4, wherein the catalyst comprises a disaccharide.

7. The method of claim 4, wherein the catalyst comprises an alcohol.

8. The method of claim 4, wherein the catalyst comprises an aldehyde.

9. The method of claim 4, wherein the catalyst comprises a catalyst selected from the group consisting of sucrose, dextrose, ethanol, methanol, ethylene glycol, levulose, glycerol, lactose, and mixtures thereof.

10. The method of claim 1, further comprising maintaining a pH of the alkaline liquid stream of at least pH 7.0.

11. The method of claim 1, wherein the gas stream comprises a flue gas stream from a coal-fired boiler further comprising sulfur dioxide, and further comprising removing at least a portion of the sulfur dioxide from the flue gas stream prior to said absorbing.

12. The method of claim 1, wherein said absorbing comprises absorbing the portion of the carbon dioxide into the alkaline liquid stream to produce absorbed carbon dioxide in an absorber comprising a wet electrostatic precipitator.

13. The method of claim 1, wherein the alkaline stream is a first alkaline stream and wherein said absorbing comprises absorbing in a first absorber at least a portion of the carbon dioxide into the first alkaline liquid stream to produce absorbed carbon dioxide and further comprising:

passing the gas stream from the first absorber to a second absorber; and

absorbing in the second absorber at least another portion of the carbon dioxide into a second alkaline liquid stream to produce absorbed carbon dioxide.

14. The method of claim 13, wherein the first alkaline liquid stream comprises calcium hydroxide, and the second alkaline liquid stream comprises sodium hydroxide.

15. The method of claim 13, wherein said catalyzing comprises catalyzing the reaction of the absorbed carbon dioxide in the first alkaline liquid stream to the form of carbonate with a catalyst.

16. The method of claim 15, wherein the catalyst comprises a catalyst selected from the group consisting of sucrose, dextrose, ethanol, methanol, ethylene glycol, levulose, glycerol, lactose, and mixtures thereof.

17. The method of claim 13, further comprising catalyzing a reaction of the absorbed carbon dioxide in the second alkaline liquid stream to a form of carbonate with a catalyst.

18. The method of claim 17, wherein the catalyst comprises a catalyst selected from the group consisting of sucrose, dextrose, ethanol, methanol, ethylene glycol, levulose, glycerol, lactose, and mixtures thereof.

19. The method of claim 13, wherein the second absorber comprises a wet electrostatic precipitator.

20. The method of claim 19, wherein the first absorber comprises a wet electrostatic precipitator.

21. The method of claim 1, wherein the alkaline liquid stream comprises sodium hydroxide and wherein said absorbing produces sodium carbonate in the alkaline liquid stream, and further comprising:

reacting a portion of the alkaline liquid stream with calcium hydroxide to produce sodium hydroxide and calcium carbonate;

separating at least a portion of the calcium carbonate from the sodium hydroxide; and

passing at least a portion of the sodium hydroxide to the alkaline liquid stream.

22. An apparatus for removing at least a portion of carbon dioxide from a gas stream, comprising:

an absorber tower;

a packed bed positioned in said absorber tower;

a gas manifold extending inside said absorber tower and positioned upstream of said packed bed and configured to deliver a gas stream to said packed bed, thereby agitating a gas and liquid in said packed bed during operation.

23. An apparatus for removing at least a portion of carbon dioxide from a gas stream, comprising:

an absorber tower;

a packed bed positioned in said absorber tower; and

a wet electrostatic precipitator positioned in said absorber tower.

24. The apparatus of claim 23, wherein said packed bed is positioned in said absorber tower downstream of said wet electrostatic precipitator.

25. The apparatus of claim 23, wherein said packed bed is positioned in said absorber tower upstream, of said wet electrostatic precipitator.

26. The apparatus of claim 23, wherein said packed bed is positioned within said wet electrostatic precipitator.