Method and Apparatus for the Removal of Carbon Dioxide from a Gas Stream

• US 20100074828A1
• Filed: 10/16/2008
• Published: 03/25/2010
• Est. Priority Date: 01/28/2008
• Status: Abandoned Application

• Current Assignee: FlueGen, Inc.
• Original Assignee: FlueGen, Inc.
• Inventors: Singh, Uday
• Application Number:
  US12/513,080
• Publication Number:
  US 20100074828A1
• Time in Patent Office: Days
• US Class Current: 423/432
• 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 2257/504 Carbon dioxide
• CPC Class Codes: B01D 47/06 Spray cleaning
• CPC Class Codes: B01D 50/60 Combinations of devices covered by groups B01D46/00 and B01D47/00
• CPC Class Codes: B01D 53/502 characterised by a specific solution or suspension
• CPC Class Codes: B01D 53/62 Carbon oxides
• CPC Class Codes: B01D 53/78 with gas-liquid contact
• CPC Class Codes: B03C 3/017 Combinations of electrostatic separation with other processes, not otherwise provided for
• CPC Class Codes: B03C 3/16 wet type
• 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: C01D 7/07 Preparation from the hydroxides
• CPC Class Codes: C01F 11/18 Carbonates
• CPC Class Codes: F23J 15/003 for supplying chemicals to fumes, e.g. using injection devices
• CPC Class Codes: F23J 2215/50 Carbon dioxide
• CPC Class Codes: F23J 2219/40 Sorption with wet devices, e.g. scrubbers
• CPC Class Codes: F23J 2219/60 Sorption with dry devices, e.g. beds
• CPC Class Codes: Y02C 20/40 of CO2
• CPC Class Codes: Y02E 20/32 Direct CO2 mitigation
• CPC Class Codes: Y02P 20/151 : Reduction of greenhouse gas [GHG] emissions, e.g. CO2
• CPC Class Codes: Y02P 70/10 : Greenhouse gas [GHG] capture, material saving, heat recovery or other energy efficient measures, e.g. motor control, characterised by manufacturing processes, e.g. for rolling metal or metal working

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.

27. 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 potassium hydroxide to produce sodium hydroxide and potassium carbonate; and

passing at least a portion of the sodium hydroxide and the potassium carbonate 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.

28. A method for removing at least a portion of carbon dioxide in a gas stream and for producing gaseous carbon dioxide, comprising:

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

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

reducing a pH of at least a portion of the alkaline liquid stream comprising the form of carbonate to produce gaseous carbon dioxide; and

collecting the gaseous carbon dioxide.

29. The method of claim 28, further comprising:

passing the gaseous carbon dioxide through a moisture separator; and

passing the gaseous carbon dioxide through a compressor.

30. The method of claim 28, wherein said reducing comprises reducing the pH to 3.0 or less.

31. The method of claim 28, wherein said reducing comprising reducing a pH of at least a portion of the alkaline liquid stream to produce sodium sulfite and further comprising:

using the sodium sulfite in a flue gas desulfurization system.

32. 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;

catalyzing a reaction of the absorbed carbon dioxide to produce a form of carbonate and water; and

using the water in a flue gas desulfurization system.

33. 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 in a wet electrostatic precipitator comprising a power supply;

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

oxidizing elemental mercury in the gas stream by repeatedly modulating the power supply between DC and AC.

34. The method of claim 33, wherein said absorbing produces absorbed carbon dioxide, and further comprising catalyzing a reaction of the absorbed carbon dioxide to produce a form of carbonate.