Promoter enhanced chilled ammonia based system and method for removal of CO 2 from flue gas stream

• US 8,168,149 B2
• Filed: 12/02/2010
• Issued: 05/01/2012
• Est. Priority Date: 12/05/2007
• Status: Expired due to Fees

• Current Assignee: General Electric Technology GmbH (GE Vernova, Inc.)
• Original Assignee: Alstom Technology Ltd. (Alstom SA)
• Inventors: Gal, Eli, Bade, Otto Morten, Jayaweera, Indira, Krishnan, Gopala
• Primary Examiner(s): Smith, Duane
• Assistant Examiner(s): Wu, Ives
• Application Number:
  US12/958,816
• Publication Number:
  US 20110070136A1
• Time in Patent Office: 516 Days
• Field of Search: 951/83, 952/36, 423/220, 423226-229, 423/242.6, 423/242.7, 423/242.4, 423/239.1
• US Class Current: 423/228
• CPC Class Codes: B01D 2251/2062 Ammonia
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: B01D 53/62 Carbon oxides
• CPC Class Codes: B01D 53/84 Biological processes
• 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

A method and system for CO₂ capture from flue gas uses an absorber vessel in which a flue gas stream containing CO₂ is contacted with an ammoniated solution to remove CO₂ from the flue gas, and a regenerator vessel in which CO₂ is released from the ammoniated solution. Parasitic energy consumption of the system can be reduced by adding to the ammoniated solution a promoter effective to enhance the formation of ammonium bicarbonate within the ammoniated solution. The amount of ammoniated solution recycled from the regenerator vessel to the absorber vessel is less than that which would be required using the ammoniated solution without the promoter for removal of the same amount of CO₂ from the flue gas.

Claims

1. A method of reducing power consumed by a system for capturing CO₂ from flue gas, the method comprising:

contacting in a contacting step a flue gas stream containing CO₂ with an ammoniated solution lean in CO₂ to provide an ammoniated solution rich in CO₂;

regenerating in a regenerating step the ammoniated solution rich in CO₂ to release CO₂ from the ammoniated solution, thereby producing the ammoniated solution lean in CO₂;

recycling the ammoniated solution lean in CO₂ from the regenerating step to the contacting step;

adding a promoter to the ammoniated solution lean in CO₂, the promoter being effective to enhance the formation of ammonium bicarbonate within the ammoniated solution lean in CO₂, thereby increasing the CO₂ absorption capacity of the ammoniated solution lean in CO₂; and

reducing the amount of ammoniated solution lean in CO₂ that is recycled from the regenerating step to the contacting step, thereby reducing the power consumed by the system.

2. The method of claim 1 wherein the promoter comprises an amine.

3. The method of claim 2 wherein the amine comprises piperazine.

4. The method of claim 3, wherein the promoter includes 0.2-2.0 molar piperazine.

5. The method of claim 4, wherein the promoter includes 0.4-1.0 molar piperazine.

6. The method of claim 1 wherein the promoter includes an enzyme.

7. A method of capturing CO₂ from flue gas using system comprising an absorber vessel in which a flue gas stream containing CO₂ is contacted with an ammoniated solution to remove CO₂ from the flue gas, and a regenerator vessel in which CO₂ is released from the ammoniated solution, the method comprising:

adding to the ammoniated solution a promoter effective to enhance the formation of ammonium bicarbonate within the ammoniated solution; and

recycling an amount of the ammoniated solution from the regenerator vessel to the absorber vessel to remove an amount of CO₂ from the flue gas, the amount of the ammoniated solution being less than that which would be required to remove the amount of CO₂ from the flue gas using the ammoniated solution without the promoter.

8. The method of claim 7 wherein the promoter comprises an amine.

9. The method of claim 8 wherein the amine comprises piperazine.

10. The method of claim 9, wherein the promoter includes 0.2-2.0 molar piperazine.

11. The method of claim 10, wherein the promoter includes 0.4-1.0 molar piperazine.

12. The method of claim 7 wherein the promoter includes an enzyme.

13. The method of claim 7, wherein the absorber vessel is reduced from the physical size required for removal of the amount of CO2 from the flue gas using the ammoniated solution without the promoter.

14. The method of claim 13, wherein the absorber vessel is reduced 50-80% from the physical size required for removal of the amount of CO₂ from the flue gas using the ammoniated solution without the promoter.