Integration of pressure swing adsorption with a power plant for co2 capture/utilization and n2 production

Patent metadata

Field	Value
Publication number	US-2017009652-A1
Application number	US-201615273800-A
Country	US
Kind code	A1
Filing date	Sep 23, 2016
Priority date	Jun 14, 2012
Publication date	Jan 12, 2017
Grant date	—

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 CO 2 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.

First claim

1 .- 19 . (canceled)

20 . A method for production of N 2 and CO 2 from a reactor exhaust stream, comprising:
passing a reactor exhaust stream comprising at least about 70 vol % N 2 and at least about 10 vol % CO 2 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 CO 2 on the adsorbent material at an adsorption temperature of at least 400° C.; recovering an N 2 stream with a purity of at least about 95 vol % from a forward end of the reactor, the recovered N 2 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 CO 2 recovery stream, the CO 2 recovery stream comprising at least about 90% of the CO 2 present in the reactor exhaust stream, the steam purge containing less than about 1.0 moles of H 2 O per mole of CO 2 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 H 2 O per mole of CO 2 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 N 2 stream is at least the adsorption temperature.

29 . A method for production of N 2 and CO 2 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 N 2 and at least about 10 vol % of CO 2 ; separating CO 2 from N 2 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 CO 2 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 N 2 stream with a purity of at least about 95vo1% from a forward end of the reactor, the recovered N 2 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 N 2 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 CO 2 recovery stream, the CO 2 recovery stream comprising at least about 90% of the CO 2 present in the reactor exhaust stream, the steam purge containing less than about 1.0 moles of H 2 O per mole of CO 2 in the reactor exhaust stream; and
separating the CO 2 recovery stream into a CO 2 product stream and water, the CO 2 product stream containing at least about 90vol % of CO 2 , wherein the at least a portion of the compressed recycle exhaust gas and the steam purge comprise at least about 95vo1% 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 CO 2 concentration of between about 10 vol % and about 20 vol %.

31 . The method of claim 29 , wherein the recycled exhaust gas has an O 2 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 N 2 stream is at least the adsorption temperature.

41 .- 42 . (canceled)

43 . A method for production of N 2 and CO 2 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

Assignees

• Exxonmobil Res & Eng Co

Inventors

• Sundaram Narasimhan
• Gupta Ramesh
• Thomann Hans
• Caram Hugo S
• Starcher Loren K
• Mittricker Franklin F
• Weston Simon C
• Weigel Scott J

Classifications

• B01D53/047 Primary

  Pressure swing adsorption · CPC title

• Y02E20/16

  Combined cycle power plant [CCPP], or combined cycle gas turbine [CCGT] · CPC title

• Y02E20/14

  Combined heat and power generation [CHP] · CPC title

• B01D2256/10

  Nitrogen · CPC title

• F02C6/18

  using the waste heat of gas-turbine plants outside the plants themselves, e.g. gas-turbine power heat plants (using waste heat as source of energy for refrigeration plants F25B27/02; using the waste heat of a gasturbine for steam generation or in a steam cycle see F01K23/10) · CPC title