Ultra Cleaning of Combustion Gas Including the Removal of Co2

• US 20080072762A1
• Filed: 04/12/2005
• Published: 03/27/2008
• Est. Priority Date: 08/06/2004
• Status: Active Grant

• Current Assignee: General Electric Technology GmbH (GE Aerospace)
• Original Assignee: EIG, Inc.
• Inventors: Gal, Eli
• Granted Patent: US 7,641,717 B2
• Time in Patent Office: Days
• US Class Current: 96/242
• 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 ultra cleaning of a contaminated combustion gas, comprising:

(a) a cooling subsystem with one or more direct and wet cooling stages to cool down a gas stream to condense water from said gas stream and to capture and remove contaminants from said gas stream;

(b) an absorbing subsystem with one or more CO₂ absorbing stages to absorb CO₂ from said cooled gas stream using an ammoniated solution or slurry; and

(c) a regeneration subsystem with one or more CO₂ regeneration stages to separate CO₂ from said absorbed and ammoniated CO₂.

2. The system as set forth in claim 1, wherein said cooling subsystem cools down said gas stream to about 0-20 degrees Celsius.

3. The system as set forth in claim 1, wherein said cooling subsystem cools down said gas stream to about 0-10 degrees Celsius.

4. The system as set forth in claim 1, wherein said CO₂ is absorbed into 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 absorbing subsystem operates at a temperature in the range of 0-20 degrees Celsius.

8. The system as set forth in claim 1, wherein said absorbing subsystem operates at a temperature in the range of 0-10 degrees Celsius.

9. The system as set forth in claim 1, wherein said absorbing subsystem generates 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, wherein said regeneration subsystem operates at a temperature in the range of 50-200 degrees Celsius.

13. The system as set forth in claim 1, wherein said regeneration subsystem operates at a temperature in the range of 100-150 degrees Celsius.

14. The system as set forth in claim 1, wherein said regeneration subsystem operates at a pressure in the range of 30-2000 psi.

15. The system as set forth in claim 1, wherein said regeneration subsystem operates at a pressure in the range of 150-400 psi.

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

(a) cooling down a gas stream with one or more direct and wet cooling stages to condense water from said gas stream and to capture and remove contaminants from said gas stream;

(b) absorbing CO₂ from said cooled gas stream with one or more CO₂ absorbing stages using an ammoniated solution or slurry; and

(c) regenerating CO₂ with one or more CO₂ regeneration stages to separate CO₂ from said absorbed and ammoniated CO₂.

17. The method as set forth in claim 16, wherein said cooling step occurs at a temperature in the range of 0-20 degrees Celsius.

18. The method as set forth in claim 16, wherein said cooling step occurs at a temperature in the range of 0-10 degrees Celsius

19. The method as set forth in claim 16, wherein said CO₂ is absorbed into 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 the species in said NH₃—

CO₂—

H₂O solution or slurry are in water-dissolved form.

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

CO₂—

H₂O solution or slurry is 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 said absorbing step occurs at a temperature in the range of 0-20 degrees Celsius.

25. The method as set forth in claim 16, wherein said absorbing step occurs at temperature in the range of 0-10 degrees Celsius.

26. The method as set forth in claim 16, wherein said absorbing step generates 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, wherein said regenerating step occurs at a temperature in the range of 50-200 degrees Celsius.

30. The method as set forth in claim 16, wherein said regenerating step occurs at a temperature in the range of 100-150 degrees Celsius.

31. The method as set forth in claim 16, wherein said regenerating step occurs at a pressure in the range of 30-2000 psi.

32. The method as set forth in claim 16, wherein said regenerating step occurs at a pressure in the range of 150-400 psi.