Ultra cleaning of combustion gas including the removal of CO2

• US 7,641,717 B2
• Filed: 04/12/2005
• Issued: 01/05/2010
• Est. Priority Date: 08/06/2004
• Status: Active Grant

• Current Assignee: General Electric Technology GmbH (GE Vernova, Inc.)
• Original Assignee: EIG, Inc.
• Inventors: Gal, Eli
• Primary Examiner(s): LAWRENCE JR, FRANK M
• Application Number:
  US11/632,537
• Publication Number:
  US 20080072762A1
• Time in Patent Office: 1,729 Days
• Field of Search: 962/34, 962/42, 951/87, 951/99, 952/23, 952/25, 952/29, 952/36, 423/220, 423/234
• US Class Current: 95/187
• CPC Class Codes: B01D 2251/2062 Ammonia
• CPC Class Codes: B01D 2252/102 Ammonia
• CPC Class Codes: B01D 53/1475 Removing carbon dioxide
• CPC Class Codes: B01D 53/62 Carbon oxides
• CPC Class Codes: B01D 53/75 Multi-step processes
• CPC Class Codes: F23J 15/006 Layout of treatment plant
• CPC Class Codes: F23J 15/06 of coolers
• CPC Class Codes: F23J 2215/50 Carbon dioxide
• CPC Class Codes: F23J 2219/50 Sorption with semi-dry devices, e.g. with slurries
• 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
• CPC Class Codes: Y02E 20/32 Direct CO2 mitigation

Abstract

Ultra cleaning of combustion gas to near zero concentration of residual contaminants followed by the capture of CO₂ is provided. The high removal efficiency of residual contaminants is accomplished by direct contact cooling and scrubbing of the gas with cold water. The temperature of the combustion gas is reduced to 0-20 degrees Celsius to achieve maximum condensation and gas cleaning effect. The CO₂ is captured from the cooled and clean flue gas in a CO₂ absorber (134) utilizing an ammoniated solution or slurry in the NH₃—CO₂H₂O system. The absorber operates at 0-20 degrees Celsius. Regeneration is accomplished by elevating the pressure and temperature of the CO₂-rich solution from the absorber. The CO₂ vapor pressure is high and a pressurized CO₂ stream, with low concentration of NH₃ and water vapor is generated. The high pressure CO₂ stream is cooled and washed to recover the ammonia and moisture from the gas.

Claims

1. A system for cleaning of a contaminated combustion gas, comprising:

(a) one or more direct and wet cooling stages configured to cool a gas stream to condense water from said gas stream and to capture and remove contaminants from said gas stream, wherein the one or more direct and wet cooling stages includes a final cooling stage configured to cool the gas stream to below ambient temperature;

(b) one or more CO₂ absorbing stages configured to absorb CO₂ from the gas stream cooled to below ambient temperature using an ammoniated solution or slurry;

(c) a pressurizer configured to pressurize the ammoniated solution or slurry with the absorbed CO₂;

and

(d) one or more CO₂ regeneration stages configured to separate absorbed CO₂ from said pressurized ammoniated solution or slurry.

2. The system as set forth in claim 1, wherein said final cooling stage is further configured to cool said gas stream to about 0-20 degrees Celsius.

3. The system as set forth in claim 1, wherein said final cooling stage is further configured to cool said gas stream to about 0-10 degrees Celsius.

4. The system as set forth in claim 1, wherein the one or more CO₂absorbing stages are further configured to absorb said CO₂ using a CO₂-lean NH₃—

CO₂—

H₂O solution or slurry.

5. The system as set forth in claim 4, wherein said CO₂-lean solution or slurry has a NH₃/CO₂ mole ratio in the range of 1.5-4.0.

6. The system as set forth in claim 4, wherein said CO₂-lean solution or slurry has a NH₃/CO₂ mole ratio in the range of 1.5-3.0.

7. The system as set forth in claim 1, wherein said one or more CO₂ absorbing stages are further configured to operate at a temperature in the range of 0-20 degrees Celsius.

8. The system as set forth in claim 1, wherein said one or more CO₂ absorbing stages are further configured to operate at a temperature in the range of 0-10 degrees Celsius.

9. The system as set forth in claim 1, wherein said one or more CO₂ absorbing stages are further configured to absorb CO₂ so as to generate a CO₂-rich NH₃—

CO₂—

H₂O solution.

10. The system as set forth in claim 9, wherein said CO₂-rich solution has a NH₃/CO₂ mole ratio in the range of 1.0-2.0.

11. The system as set forth in claim 9, wherein said CO₂-rich solution has a NH₃/CO₂ mole ratio in the range of 1.0-1.5.

12. The system as set forth in claim 1, further comprising:

a heater configured to heat the ammoniated solution or slurry with the absorbed CO₂ to a temperature in the range of 50-200 degrees Celsius;

wherein the one or more CO₂ regeneration stages are further configured to separate absorbed CO₂ from said pressurized and heated ammoniated solution or slurry.

13. The system as set forth in claim 1, further comprising:

a heater configured to heat the ammoniated solution or slurry with the absorbed CO₂ to a temperature in the range of 100-150degrees Celsius;

wherein the one or more CO₂ regeneration stages are further configured to separate absorbed CO₂ from said pressurized and heated ammoniated solution or slurry.

14. The system as set forth in claim 1, wherein said pressurizer is further configured to pressurize the ammoniated solution or slurry to a pressure in the range of 30-2000 psi.

15. The system as set forth in claim 1, wherein said pressurizer is further configured to pressurize the ammoniated solution or slurry to a pressure in the range of 150-400 psi.

16. A method for cleaning of a contaminated combustion gas, comprising:

(a) cooling down a gas stream to condense water from said gas stream and to capture and remove contaminants from said gas stream, wherein the gas stream is cooled to below ambient temperature;

(b) absorbing CO₂ from said cooled gas stream using an ammoniated solution or slurry, wherein the cooled gas stream and ammoniated solution or slurry are maintained below ambient temperature during said absorbing;

(c) pressurizing the ammoniated solution or slurry with the absorbed CO₂; and

(d) regenerating CO₂ by separating CO₂ from said pressurized ammoniated solution or slurry.

17. The method as set forth in claim 16, wherein said gas stream is cooled to a temperature in the range of 0-20 degrees Celsius.

18. The method as set forth in claim 16, wherein said gas stream is cooled to a temperature in the range of 0-10 degrees Celsius.

19. The method as set forth in claim 16, wherein the ammoniated solution or slurry used to absorb said CO₂ is a CO₂ lean NH₃—

CO₂—

H₂O solution or slurry.

20. The method as set forth in claim 19, wherein said CO₂-lean solution or slurry has a NH₃/CO₂ mole ratio in the range of 1.5-4.0.

21. The method as set forth in claim 19, wherein said CO₂-lean solution or slurry has a NH₃/CO₂ mole ratio in the range of 1.5-3.0.

22. The method as set forth in claim 19, wherein said NH₃—

CO₂—

H₂O solution or slurry is in water-dissolved form.

23. The method as set forth in claim 19, wherein the species in said NH₃—

CO₂—

H₂O solution or slurry are concentrated such to contain dissolved and suspended solids having ammonium carbonate, (NH₄) ₂CO₃, and ammonium bicarbonate, NH₄HCO₃, salts.

24. The method as set forth in claim 16, wherein the cooled gas stream and ammoniated solution or slurry maintained at a temperature in the range of 0-20 degrees Celsius during said absorbing.

25. The method as set forth in claim 16, wherein the cooled gas stream and ammoniated or slurry are maintained at a temperature in the range of 0-10 degrees Celsius during said absorbing.

26. The method as set forth in claim 16, wherein said ammoniated solution or slurry with the absorbed CO₂ is a CO₂-rich NH₃—

CO₂—

H₂O solution.

27. The method as set forth in claim 26, wherein said CO₂-rich solution has a NH₃/CO₂ mole ratio in the range of 1.0-2.0.

28. The method as set forth in claim 26, wherein said CO₂-rich solution has a NH₃/CO₂ mole ratio in the range of 1.0-1.5.

29. The method as set forth in claim 16, further comprising:

heating the ammoniated solution or slurry with the absorbed CO₂ to a temperature in the range of 50-200 degrees Celsius;

wherein the pressurized ammoniated solution or slurry from which CO₂ is separated to regenerate CO₂ is the pressurized and heated ammoniated solution or slurry.

30. The method as set forth in claim 16, further comprising:

heating the pressurized ammoniated solution or slurry with the absorbed CO₂ to a temperature in the range of 100-150 degrees Celsius;

wherein the pressurized ammoniated solution or slurry from which CO₂ is separated to regenerate CO₂ is the pressurized and heated ammoniated solution or slurry.

31. The method as set forth in claim 16, wherein the ammoniated solution or slurry with the absorbed CO₂ is pressurized to a pressure in the range of 30-2000 psi.

32. The method as set forth in claim 16, wherein the ammoniated solution or slurry with the absorbed CO₂ is pressurized to a pressure in the range of 150-400 psi.