Ultra cleaning of combustion gas including the removal of CO
View Patent ↗Ultra cleaning of combustion gas to near zero concentration of residual contaminants followed by the capture of CO 2 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 CO 2 is captured from the cooled and clean flue gas in a CO 2 absorber ( 134 ) utilizing an ammoniated solution or slurry in the NH 3 —CO 2 H 2 O system. The absorber operates at 0-20 degrees Celsius. Regeneration is accomplished by elevating the pressure and temperature of the CO 2 -rich solution from the absorber. The CO 2 vapor pressure is high and a pressurized CO 2 stream, with low concentration of NH 3 and water vapor is generated. The high pressure CO 2 stream is cooled and washed to recover the ammonia and moisture from the gas.
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 CO 2 absorbing stages configured to absorb CO 2 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 CO 2 ;and
(d) one or more CO 2 regeneration stages configured to separate absorbed CO 2 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 CO 2 absorbing stages are further configured to absorb said CO 2 using a CO 2 -lean NH 3 —CO 2 —H 2 O solution or slurry.
5. The system as set forth in claim 4 , wherein said CO 2 -lean solution or slurry has a NH 3 /CO 2 mole ratio in the range of 1.5-4.0.
6. The system as set forth in claim 4 , wherein said CO 2 -lean solution or slurry has a NH 3 /CO 2 mole ratio in the range of 1.5-3.0.
7. The system as set forth in claim 1 , wherein said one or more CO 2 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 CO 2 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 CO 2 absorbing stages are further configured to absorb CO 2 so as to generate a CO 2 -rich NH 3 —CO 2 —H 2 O solution.
10. The system as set forth in claim 9 , wherein said CO 2 -rich solution has a NH 3 /CO 2 mole ratio in the range of 1.0-2.0.
11. The system as set forth in claim 9 , wherein said CO 2 -rich solution has a NH 3 /CO 2 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 CO 2 to a temperature in the range of 50-200 degrees Celsius;
wherein the one or more CO 2 regeneration stages are further configured to separate absorbed CO 2 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 CO 2 to a temperature in the range of 100-150degrees Celsius;
wherein the one or more CO 2 regeneration stages are further configured to separate absorbed CO 2 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 CO 2 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 CO 2 ; and
(d) regenerating CO 2 by separating CO 2 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 CO 2 is a CO 2 lean NH 3 —CO 2 —H 2 O solution or slurry.
20. The method as set forth in claim 19 , wherein said CO 2 -lean solution or slurry has a NH 3 /CO 2 mole ratio in the range of 1.5-4.0.
21. The method as set forth in claim 19 , wherein said CO 2 -lean solution or slurry has a NH 3 /CO 2 mole ratio in the range of 1.5-3.0.
22. The method as set forth in claim 19 , wherein said NH 3 —CO 2 —H 2 O solution or slurry is in water-dissolved form.
23. The method as set forth in claim 19 , wherein the species in said NH 3 —CO 2 —H 2 O solution or slurry are concentrated such to contain dissolved and suspended solids having ammonium carbonate, (NH 4 ) 2 CO 3 , and ammonium bicarbonate, NH 4 HCO 3 , 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 CO 2 is a CO 2 -rich NH 3 —CO 2 —H 2 O solution.
27. The method as set forth in claim 26 , wherein said CO 2 -rich solution has a NH 3 /CO 2 mole ratio in the range of 1.0-2.0.
28. The method as set forth in claim 26 , wherein said CO 2 -rich solution has a NH 3 /CO 2 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 CO 2 to a temperature in the range of 50-200 degrees Celsius;
wherein the pressurized ammoniated solution or slurry from which CO 2 is separated to regenerate CO 2 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 CO 2 to a temperature in the range of 100-150 degrees Celsius;
wherein the pressurized ammoniated solution or slurry from which CO 2 is separated to regenerate CO 2 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 CO 2 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 CO 2 is pressurized to a pressure in the range of 150-400 psi.