INTEGRATION OF PRESSURE SWING ADSORPTION WITH A POWER PLANT FOR CO2 CAPTURE/UTILIZATION AND N2 PRODUCTION

• US 20130333391A1
• Filed: 06/13/2013
• Published: 12/19/2013
• Est. Priority Date: 06/14/2012
• Status: Active Grant

• Current Assignee: Exxonmobil Upstream Research Company (Exxon Mobil Corporation)
• Original Assignee: ExxonMobil Research & Engineering Company (Exxon Mobil Corporation)
• Inventors: GUPTA, RAMESH, WESTON, SIMON C., SUNDARAM, NARASIMHAN, THOMANN, HANS, CARAM, HUGO S., STARCHER, LOREN K., Mittricker, FRANKLIN F., WEIGEL, SCOTT J.
• Granted Patent: US 9,476,356 B2
• Time in Patent Office: Days
• US Class Current: 60/783
• CPC Class Codes: B01D 2253/1124 Metal oxides
• CPC Class Codes: B01D 2256/10 Nitrogen
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: B01D 2258/0283 Flue gases
• CPC Class Codes: B01D 2259/40056 Gases other than recycled product or process gas
• CPC Class Codes: B01D 53/0462 Temperature swing adsorption
• CPC Class Codes: B01D 53/047 Pressure swing adsorption
• CPC Class Codes: F01K 17/04 for specific purposes other than heating F01K17/06 takes precedence
• CPC Class Codes: F02C 3/34 with recycling of part of the working fluid, i.e. semi-closed cycles with combustion products in the closed part of the cycle
• CPC Class Codes: F02C 6/04 Gas-turbine plants providing heated or pressurised working fluid for other apparatus, e.g. without mechanical power output F02C6/18 takes precedence ; for a fluidised-bed combustor F02C3/205
• CPC Class Codes: F02C 9/16 Control of working fluid flow F02C9/48 takes precedence; control of air-intake flow F02C7/057
• CPC Class Codes: F05D 2220/31 in steam turbines
• CPC Class Codes: F05D 2220/32 in gas turbines
• CPC Class Codes: F05D 2260/61 Removal of CO2 removal of CO2 from waste gases B01D53/62
• CPC Class Codes: F23J 2215/50 Carbon dioxide
• CPC Class Codes: Y02C 20/40 of CO2
• CPC Class Codes: Y02E 20/14 Combined heat and power generation [CHP]
• CPC Class Codes: Y02E 20/16 Combined cycle power plant [CCPP], or combined cycle gas turbine [CCGT]

Abstract

Systems and methods are provided for combined cycle power generation while reducing or mitigating emissions during power generation. Recycled exhaust gas from a power generation combustion reaction can be separated using a swing adsorption process so as to generate a high purity CO₂ stream while reducing/minimizing the energy required for the separation and without having to reduce the temperature of the exhaust gas. This can allow for improved energy recovery while also generating high purity streams of carbon dioxide and nitrogen.

Claims

1. A method for generating power, comprising:

compressing a recycled exhaust gas in a main compressor to generate a compressed recycle exhaust gas, the compressed recycle exhaust gas having a recycle temperature from about 400°

C. to about 500°

C. and a recycle pressure from about 10 bara (about 1.0 MPaa) to about 30 bara (about 3.0 MPaa), the recycled exhaust gas comprising at least about 70 vol % of N₂ and at least about 10vol % of CO₂;

compressing enriched air in an inlet compressor to generate a compressed oxidant;

passing a first portion of the compressed recycle exhaust gas into a combustion chamber;

stoichiometrically combusting the compressed oxidant and a fuel in a combustion chamber and in the presence of the first portion of the compressed recycle exhaust gas, thereby generating a discharge stream, wherein the first portion of the compressed recycle exhaust gas acts as a diluent configured to moderate the temperature of the discharge stream;

expanding the discharge stream in an expander to at least partially drive the main compressor and generate the recycled exhaust gas;

passing a second portion of the compressed recycled exhaust gas into a swing adsorption reactor comprising an adsorbent material;

adsorbing CO₂ on the adsorbent material at an adsorption temperature that differs from the recycle temperature by less than about 20°

C. and at an adsorption pressure that differs from the recycle pressure by less than about 1 bar (about 0.1 MPa);

recovering an N₂ stream with a purity of at least about 95vol % from a forward end of the reactor, the recovered N₂ stream having a pressure that differs from the separation pressure by less than about 0.5 bar (about 50 kPa);

reducing the pressure in the swing adsorption reactor to a pressure from about 1.0 bara (about 0.1 MPaa) to about 4.0 bara (about 0.4 MPaa) by outputting a blow down stream from at least one end of the reactor; and

purging the swing adsorption reactor with a steam purge at a pressure from about 1.0 bara (about 0.1 MPaa) to about 4.0 bara (about 0.4 MPaa) to generate a CO₂ recovery stream, the CO₂ recovery stream comprising at least about 90% of the CO₂ present in the second portion of the recycled exhaust gas, the steam purge containing less than 1.0 mole of H₂O per mole of CO₂ in the second portion of the recycled exhaust gas.

2. The method of claim 1, wherein the passing, the adsorbing, the recovering, the reducing, and the purging comprise a pressure swing adsorption cycle, the second portion of the recycled exhaust gas and the steam purge comprising at least about 95 vol % of gases introduced into the swing adsorption reactor during the pressure swing adsorption cycle.

3. The method of claim 1, further comprising passing a second purge stream through the swing adsorption reactor to generate a second CO₂ recovery stream, the second purge stream having a different composition than the steam purge.

4. The method of claim 3, wherein the passing, the adsorbing, the recovering, the reducing, and the purging comprise a pressure swing adsorption cycle, the second portion of the recycled exhaust gas, the steam purge, and the second purge stream comprising at least about 95 vol % of the gases introduced into the swing adsorption reactor during the pressure swing adsorption cycle.

5. The method of claim 1, further comprising separating the CO₂ recovery stream into a CO₂ product stream and water, the CO₂ product stream containing at least about 90 vol % of CO₂.

6. The method of claim 5, wherein the CO₂ product stream further comprises N₂.

7. The method of claim 1, wherein the compressed oxidant has an oxygen concentration between about 30 vol % and about 50 vol %.

8. The method of claim 7, wherein generating the compressed oxidant further comprises mixing the enriched air with atmospheric air.

9. The method of claim 1, wherein the recycled exhaust gas has a CO₂ concentration between about 10 vol % and about 20 vol %.

10. The method of claim 1, wherein the recycled exhaust gas has an O₂ concentration of about 1 vol % or less.

11. The method of claim 1, wherein the adsorbent comprises an alkali metal carbonate and an oxide of an alkaline earth metal or a transition metal.

12. The method of claim 11, wherein the alkali metal carbonate is potassium carbonate, lithium carbonate, or sodium carbonate.

13. The method of claim 11, wherein the adsorbent comprises a transition metal oxide of a transition metal that forms an oxide with the metal in a +2 or +3 oxidation state.

14. The method of claim 11, wherein the adsorbent comprises at least one of lithium carbonate and potassium carbonate and at least one of lanthanum oxide, yttrium oxide, and magnesium oxide.

15. The method of claim 1, wherein the adsorbent comprises an alkaline earth metal carbonate and an oxide of a transition metal.

16. The method of claim 15, wherein the alkaline earth metal carbonate is magnesium carbonate or calcium carbonate.

17. The method of claim 15, wherein the adsorbent comprises a transition metal oxide of a transition metal that forms an oxide with the metal in a +2 or +3 oxidation state.

18. The method of claim 15, wherein the adsorbent comprises at least one of magnesium carbonate and calcium carbonate and at least one of lanthanum oxide, yttrium oxide, and magnesium oxide.

19. The method of claim 1, wherein the temperature of the recovered N₂ stream is at least the adsorption temperature.

20. A method for production of N₂ and CO₂ from a reactor exhaust stream, comprising:

passing a reactor exhaust stream comprising at least about 70 vol % N₂ and at least about 10 vol % CO₂ into a swing adsorption reactor comprising an adsorbent material, the reactor exhaust stream having a pressure between about 10 bara (about 1.0 MPaa) to about 30 bara (about 3.0 MPaa);

adsorbing CO₂ on the adsorbent material at an adsorption temperature of at least 400°

C.;

recovering an N₂ stream with a purity of at least about 95 vol % from a forward end of the reactor, the recovered N₂ stream having a pressure that differs from the pressure of the reactor exhaust stream by about 0.5 bar (about 50 kPa) or less;

reducing the pressure in the swing adsorption reactor to a pressure from about 1.0 bara (about 0.1 MPaa) to about 4.0 bara (about 0.4 MPaa) by outputting a blow down stream from at least one end of the reactor; and

purging the swing adsorption reactor with a steam purge at a pressure from about 1.0 bara (about 0.1 MPaa) to about 4.0 bara (about 0.4 MPaa) to generate a CO₂ recovery stream, the CO₂ recovery stream comprising at least about 90% of the CO₂ present in the reactor exhaust stream, the steam purge containing less than about 1.0 moles of H₂O per mole of CO₂ in the reactor exhaust stream.

21. The method of claim 20, wherein the passing, the adsorbing, the recovering, the reducing, and the purging comprise a pressure swing adsorption cycle, the reactor exhaust stream and the steam purge comprising at least about 95 vol % of the gases introduced into the swing adsorption reactor during the pressure swing adsorption cycle.

22. The method of claim 20, further comprising repressurizing the swing adsorption reactor to a pressure of at least about 10 bara (about 1.0 MPaa) with the reactor exhaust stream.

23. The method of claim 20, wherein the reactor exhaust stream comprises a power plant flue stream, a refinery flue stream, or a combination thereof

24. The method of claim 20, wherein the reactor exhaust stream is generated by compressing a flue stream from stoichiometric combustion of a fuel as part of generating power using a turbine.

25. The method of claim 20, wherein the steam purge contains less than 0.8 moles of H₂O per mole of CO₂ in the reactor exhaust stream.

26. The method of claim 20, wherein reducing the pressure in the swing adsorption reactor comprises outputting a first blow down stream from the forward end of the reactor.

27. The method of claim 26, wherein reducing the pressure in the swing adsorption reactor further comprises outputting a second blowdown stream from the forward end of the reactor and a third blow down stream from a back end of the reactor after outputting the first blowdown stream.

28. The method of claim 20, wherein the temperature of the recovered N₂ stream is at least the adsorption temperature.

29. A method for production of N₂ and CO₂ from a reactor exhaust stream, comprising:

compressing a recycled exhaust gas to generate a compressed recycle exhaust gas, the compressed recycle exhaust gas having a recycle temperature from about 400°

C. to about 500°

C. and a recycle pressure from about 10 bara (about 1.0 MPaa) to about 30 bara (about 3.0 MPaa), the recycled exhaust gas comprising at least about 70 vol % of N₂ and at least about 10 vol % of CO₂;

separating CO₂ from N₂ in at least a portion of the compressed recycle exhaust gas in a cyclical pressure swing adsorption process, a process cycle comprising;

passing the at least a portion of the compressed recycle exhaust gas into a swing adsorption reactor comprising an adsorbent material, the reactor exhaust stream having a pressure between about 10 bara (about 1.0 MPaa) to about 30 bara (about 3.0 MPaa);

adsorbing CO₂ on the adsorbent material at an adsorption temperature that differs from the recycle temperature by less than about 20°

C. and at an adsorption pressure that differs from the recycle pressure by less than about 1 bar (0.1 MPa);

recovering an N₂ stream with a purity of at least about 95vol % from a forward end of the reactor, the recovered N₂ stream having a pressure that differs from the pressure of the reactor exhaust stream by about 0.5 bar (about 50 kPa) or less, the recovered N₂ stream having a temperature that differs from the recycle temperature by 20°

C. or less;

reducing the pressure in the swing adsorption reactor to a pressure from about 1.0 bara (about 0.1 MPaa) to about 4.0 bara (about 0.4 MPaa) by outputting a blow down stream from at least one end of the reactor;

purging the swing adsorption reactor with a steam purge at a pressure from about 1.0 bara (about 0.1 MPaa) to about 4.0 bara (about 0.4 MPaa) to generate a CO₂ recovery stream, the CO₂ recovery stream comprising at least about 90% of the CO₂ present in the reactor exhaust stream, the steam purge containing less than about 1.0 moles of H₂O per mole of CO₂ in the reactor exhaust stream; and

separating the CO₂ recovery stream into a CO₂ product stream and water, the CO₂ product stream containing at least about 90vol % of CO₂,

wherein the at least a portion of the compressed recycle exhaust gas and the steam purge comprise at least about 95vol % of the gases introduced into the swing adsorption reactor during a process cycle.

30. The method of claim 29, wherein the recycled exhaust gas has a CO₂ concentration of between about 10 vol % and about 20 vol %.

31. The method of claim 29, wherein the recycled exhaust gas has an O₂ concentration of about 1 vol % or less.

32. The method of claim 29, wherein the adsorbent comprises an alkali metal carbonate and an oxide of an alkaline earth metal or a transition metal.

33. The method of claim 32, wherein the alkali metal carbonate is potassium carbonate, lithium carbonate, or sodium carbonate.

34. The method of claim 32, wherein the adsorbent comprises a transition metal oxide of a transition metal that forms an oxide with the metal in a +2 or +3 oxidation state.

35. The method of claim 32, wherein the adsorbent comprises at least one of lithium carbonate and potassium carbonate and at least one of lanthanum oxide, yttrium oxide, and magnesium oxide.

36. The method of claim 29, wherein the adsorbent comprises an alkaline earth metal carbonate and an oxide of a transition metal.

37. The method of claim 36, wherein the alkaline earth metal carbonate is magnesium carbonate or calcium carbonate.

38. The method of claim 36, wherein the adsorbent comprises a transition metal oxide of a transition metal that forms an oxide with the metal in a +2 or +3 oxidation state.

39. The method of claim 36, wherein the adsorbent comprises at least one of magnesium carbonate and calcium carbonate and at least one of lanthanum oxide, yttrium oxide, and magnesium oxide.

40. The method of claim 29, wherein the temperature of the recovered N₂ stream is at least the adsorption temperature.

41. A method for generating power, comprising:

compressing a recycled exhaust gas in a main compressor to generate a compressed recycle exhaust gas, the compressed recycle exhaust gas having a recycle temperature from about 400°

C. to about 500°

C. and a recycle pressure from about 10 bara (about 1.0 MPaa) to about 30 bara (about 3.0 MPaa), the recycled exhaust gas comprising at least about 70 vol % of N₂ and at least about 10 vol % of CO₂;

compressing enriched air in an inlet compressor to generate a compressed oxidant;

passing a first portion of the compressed recycle exhaust gas into a combustion chamber;

stoichiometrically combusting the compressed oxidant and a fuel in a combustion chamber and in the presence of the first portion of the compressed recycle exhaust gas, thereby generating a discharge stream, wherein the first portion of the compressed recycle exhaust gas acts as a diluent configured to moderate the temperature of the discharge stream;

expanding the discharge stream in an expander to at least partially drive the main compressor and generate the recycled exhaust gas;

passing a second portion of the recycled exhaust gas into a swing adsorption reactor comprising an adsorbent material;

adsorbing CO₂ on the adsorbent material at an adsorption temperature that differs from the recycle temperature by less than about 20°

C. and at an adsorption pressure that differs from the recycle pressure by less than about 1 bar (about 0.1 MPa);

recovering an N₂ stream with a purity of at least about 95 vol % from a forward end of the reactor, the recovered N₂ stream having a pressure that differs from the separation pressure by less than about 0.5 bar (about 50 kPa);

optionally reducing the pressure in the swing adsorption reactor to a pressure of at least 3.0 bara (0.3 MPaa) by outputting a blow down stream from at least one end of the reactor; and

purging the swing adsorption reactor with a purge containing no intentionally added water at a pressure from 3.0 bara (0.3 MPaa) to about 20.0 bara (about 2.0 MPaa) to generate a CO₂ recovery stream, the CO₂ recovery stream comprising at least about 90% of the CO₂ present in the second portion of the recycled exhaust gas.

42. A method for production of relatively high purity N₂ and CO₂ streams from a reactor exhaust stream, comprising:

passing a reactor exhaust stream comprising at least about 70 vol % N₂ and at least about 10 vol % CO₂ into a swing adsorption reactor comprising an adsorbent material, the reactor exhaust stream having a pressure between about 10 bara (about 1.0 MPaa) to about 30 bara (about 3.0 MPaa);

adsorbing CO₂ on the adsorbent material at an adsorption temperature of at least 400°

C.;

recovering an N₂ stream with a purity of at least about 95 vol % from a forward end of the reactor, the recovered N₂ stream having a pressure that differs from the pressure of the reactor exhaust stream by about 0.5 bar (about 50 kPa) or less;

optionally reducing the pressure in the swing adsorption reactor to a pressure of at least 3.0 bara (0.3 MPaa) by outputting a blow down stream from at least one end of the reactor; and

purging the swing adsorption reactor with a purge containing no intentionally added water at a pressure from 3.0 bara (0.3 MPaa) to about 20.0 bara (about 2.0 MPaa) to generate a CO₂ recovery stream, the CO₂ recovery stream comprising at least about 90% of the CO₂ present in the second portion of the recycled exhaust gas.

43. A method for production of N₂ and CO₂ from a reactor exhaust stream, comprising:

compressing a recycled exhaust gas to generate a compressed recycle exhaust gas, the compressed recycle exhaust gas having a recycle temperature from about 400°

C. to about 500°

C. and a recycle pressure from about 10 bara (about 1.0 MPaa) to about 30 bara (about 3.0 MPaa), the recycled exhaust gas comprising at least about 70 vol % of N₂ and at least about 10 vol % of CO₂;

separating CO₂ from N₂ in at least a portion of the compressed recycle exhaust gas in a cyclical pressure swing adsorption process, a process cycle comprising;

passing the at least a portion of the compressed recycle exhaust gas into a swing adsorption reactor comprising an adsorbent material, the reactor exhaust stream having a pressure between about 10 bara (about 1.0 MPaa) to about 30 bara (about 3.0 MPaa);

adsorbing CO₂ on the adsorbent material at an adsorption temperature that differs from the recycle temperature by less than about 20°

C. and at an adsorption pressure that differs from the recycle pressure by less than about 1 bar (0.1 MPa);

recovering an N₂ stream with a purity of at least about 95 vol % from a forward end of the reactor, the recovered N₂ stream having a pressure that differs from the pressure of the reactor exhaust stream by about 0.5 bar (about 50 kPa) or less, the recovered N₂ stream having a temperature that differs from the recycle temperature by 20°

C. or less;

reducing the pressure in the swing adsorption reactor to a pressure from about 1.0 bara (about 0.1 MPaa) to about 5.0 bara (about 0.5 MPaa) by outputting a blow down stream from at least one end of the reactor;

purging the swing adsorption reactor with a steam purge at a pressure from about 1.0 bara (about 0.1 MPaa) to about 5.0 bara (about 0.4 MPaa) to generate a CO₂ recovery stream, the CO₂ recovery stream comprising at least about 60% of the CO₂ present in the reactor exhaust stream, the steam purge containing less than about 1.5 moles of H₂O per mole of CO₂ in the reactor exhaust stream; and

separating the CO₂ recovery stream into a CO₂ product stream and water, the CO₂ product stream containing from about 60 vol % to about 99.5 vol % of CO₂,

wherein the at least a portion of the compressed recycle exhaust gas and the steam purge comprise at least about 90 vol % of the gases introduced into the swing adsorption reactor during a process cycle.