SYSTEM FOR RECOVERY OF AMMONIA FROM LEAN SOLUTION IN A CHILLED AMMONIA PROCESS UTILIZING RESIDUAL FLUE GAS

• US 20130255495A1
• Filed: 03/30/2012
• Published: 10/03/2013
• Est. Priority Date: 03/30/2012
• Status: Active Grant

• Current Assignee: Altom Technology, Ltd., General Electric Technology GmbH (GE Aerospace)
• Original Assignee: Alstom Technology Ltd. (Alstom SA)
• Inventors: Askander, Jalal, Kozak, Fred
• Granted Patent: US 8,864,879 B2
• Time in Patent Office: Days
• US Class Current: 95/165
• CPC Class Codes: B01D 2252/102 Ammonia
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: B01D 2258/0283 Flue gases
• CPC Class Codes: B01D 2259/124 Liquid reactants
• CPC Class Codes: B01D 53/62 Carbon oxides
• CPC Class Codes: B01D 53/96 Regeneration, reactivation or recycling of reactants
• CPC Class Codes: Y02C 20/40 of CO2

Abstract

Disclosed herein is a method comprising contacting a residual flue gas stream with a lean solution stream in an appendix stripper; where the residual flue gas stream comprises nitrogen, oxygen and moisture; and where the lean solution stream comprises ammonium, ammonium carbonate, ammonium bicarbonate and ammonium sulfate; forming a vapor phase that comprises ammonia vapor, water vapor, carbon dioxide and nitrogen; forming a liquid phase that comprises water, ammonium sulfate and ammonia; discharging the vapor phase to a capture system; and discharging the liquid phase to a direct contact cooler.

Claims

1. A method comprising:

contacting a residual flue gas stream with a lean solution stream in an appendix stripper;

where the residual flue gas stream comprises nitrogen, oxygen and moisture; and

where the lean solution stream comprises ammonium, ammonium carbonate, ammonium bicarbonate and ammonium sulfate;

forming a vapor phase that comprises ammonia vapor, water vapor, carbon dioxide and nitrogen;

forming a liquid phase that comprises water, ammonium sulfate and ammonia;

discharging the vapor phase to a capture system; and

discharging the liquid phase to a direct contact cooler.

2. The method of claim 1, where the residual flue gas stream is at a temperature of about 25 to about 50°

C.

3. The method of claim 1, further comprising heating the residual flue gas stream in a direct contact heater prior to discharging it into the appendix stripper.

4. The method of claim 1, where the method does not use steam or electrical energy.

5. The method of claim 1, where the appendix stripper is operated at a pressure effective to facilitate circulation.

6. The method of claim 1, where the ammonium sulfate is not decomposed.

7. The method of claim 1, where the residual flue gas stream with the lean solution stream are introduced at opposite ends of the appendix stripper.

8. The method of claim 6, where the residual flue gas stream and the lean solution stream travel through the appendix stripper in opposing directions.

9. The method of claim 1, where the liquid phase comprises 0.02 to 0.04 M ammonia.

10. A system comprising:

a capture system;

the capture system being operative to produce a residual flue gas stream by absorbing carbon dioxide from a flue gas stream by contacting it with an ionic solution comprising ammonia;

a regeneration system in fluid communication with the capture system;

the regeneration system being operative to remove carbon dioxide from the ionic solution to form a lean ionic solution;

a direct contact heater;

the direct contact heater being in fluid communication with the capture system and being operative to heat the residual flue gas stream; and

an appendix stripper;

the appendix stripper being operative to facilitate contact between the residual flue gas stream and the lean solution stream.

11. The system of claim 10, where the flue gas stream is at a temperature of about 25 to about 50°

C. and the lean solution stream is at a temperature of about 100 to about 150°

C.

12. The system of claim 10, where the appendix stripper is further operative to form a vapor phase that comprises ammonia vapor, water vapor, carbon dioxide and nitrogen.

13. The system of claim 10, where the appendix stripper is further operative to form a liquid phase that comprises water, ammonium sulfate and 0.02 to 0.04 M ammonia.

14. The system of claim 12, where the vapor phase is discharged to the capture system.

15. The system of claim 13, where the liquid phase is discharged to a direct contact cooler.

16. The system of claim 10, where the appendix stripper is further in fluid communication with the capture system.

17. The system of claim 10, further comprising a blower located upstream of the appendix stripper.

18. The system of claim 10, where the appendix stripper comprises structured or random packing to facilitate mass transfer.