IP Library › Granted Patent US 7,815,892
Granted Patent B2
US 7,815,892 · App. 10/912,820 · Granted Oct 19, 2010

Integration of hydrogen and power generation using pressure swing reforming

Assignee: ExxonMobil Research and Engineering Company
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Quick Facts
Patent No.
US 7,815,892
App. No.
10/912,820
Granted
Oct 19, 2010
Kind
B2
Abstract

The invention provides a method for generating power with a gas turbine which utilizes pressure swing reforming under conditions that facilitate CO 2 capture. First a synthesis gas stream at a first pressure is produced in a pressure swing reformer. Next the synthesis gas stream is subjected to a high temperature water gas shift process to produce a CO 2 containing hydrogen enriched stream from which hydrogen and CO 2 each are separated. The separated hydrogen in turn is combusted with air to produce a gas turbine and the separated CO 2 is easily sequestered.

Claims (23)

1. A method for producing power under conditions that facilitate CO 2 capture, said method comprising:

(a) producing a synthesis gas by a pressure swing reforming process comprising a reforming stage and a regeneration stage, said reforming stage method comprising:

(i) passing a feed stream under high pressure conditions and comprising a hydrocarbon and steam through a first end of a first, reforming zone containing packing materials and a steam reforming catalyst at an elevated temperature to produce a high pressure synthesis gas stream ranging in pressure from about ten (10) atmospheres to about one hundred (100) atmospheres;

(ii) passing substantially all the synthesis gas stream of step (a) through the first end of a second, recuperating zone, containing bed packing materials at a temperature lower than the first zone, thereby transferring sensible heat from the synthesis gas stream to the packing material in the second, recuperating zone, and providing a high pressure synthesis gas cooled to a temperature of about the packing material at the second end;

said steps (i) and (ii) being conducted at conditions sufficient to provide a synthesis gas at said second end of said second zone in the range of about 200° C. to about 650° C. said conditions comprising: combined reforming and regenerative cooling steps (i) and (ii) are done at a reforming space velocity C 1 GHSV greater than about 1000 hr −1 calculated using a combined volume of both the first and second zones and, bed packing providing a heat transfer parameter ΔT HT between about 0.1° C. and about 500°, to produce a time-averaged level of reforming conversion of greater than about 80%;

(iii) removing substantially all of the high pressure synthesis gas from the second zone;

And regeneration stage method comprising:

(iv) introducing a oxygen containing gas into the second end of the second zone, in reverse flow to steps (i) and (ii), combusting said gas and a regenerative fuel at about an interface between the recuperating zone and the reforming zone to re-heat the packing material of the first, reforming zone sufficient for the synthesis gas production of step (i);

(v) removing a regeneratively cooled flue gas from the first end of the first zone;

(b) Enriching and separating hydrogen from the synthesis gas by a process comprising:

(i) introducing said synthesis gas into a water-gas shift reaction zone to provide a shifted gas stream enriched in CO 2 and enriched in hydrogen;

(ii) passing the shifted gas stream through a hydrogen separation zone to separate high pressure hydrogen from CO2;

(iii) removing the high pressure hydrogen-containing gas stream from the separation zone;

(iv) removing the CO2 containing gas stream from the separation zone; and

(c) introducing at least part of the separated hydrogen as fuel to a combustion zone of a gas turbine together with an oxidant to produce power whereby substantially the only CO 2 produced is that contained in the CO 2 containing gas stream from the separation zone thereby producing power under conditions that facilitate CO 2 capture.

2. The method of claim 1 wherein the fuel of step (a)(iv) is a portion of the high pressure hydrogen-containing gas stream removed from the separation zone and wherein the regeneration stage is conducted at a lower pressure than the reforming stage.

3. The method of claim 2 wherein the amount of feed in step (a) is sufficient to produce sufficient hydrogen for step (a-iv) and (c).

4. The method of claim 2 wherein the amount of feed in step (a) is in excess of that needed to produce sufficient hydrogen for step (a-iv) and (c) whereby power and hydrogen are produced.

5. The method of claim 2 wherein steps (b)(ii) through (b)(iv) are conducted in a membrane separator in which a portion of the flue gas from step (a)(v) is fed to the separator as a sweep gas.

6. The method of claim 1 wherein the separation comprises use of a solvent-based system to absorb CO 2 from the hydrogen enriched stream.

7. The method of claim 1 wherein the separation comprises use of solid adsorbents to adsorb CO 2 from the hydrogen enriched stream.

8. The method of claim 1 wherein at least step (a) is conducted at a space velocity ranging from about 1,000 to about 50,000.

9. The method of claim 1 wherein the regeneration stage method is conducted at pressures ranging from about five atmospheres to about thirty atmospheres.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 23, 2010
From: HERSHKOWITZ, FRANK; DECKMAN, HARRY W.
To: EXXONMOBIL RESEARCH AND ENGINEERING COMPANY
Reel/Frame 024734/0688 →
Continuity (4)
Continuation In Part 1077191900 · Feb 4, 2004
Continuation In Part 1075665200 · Jan 13, 2004
Provisional Application 6045090300 · Feb 28, 2003
Related Publication 20050201929A1 · Sep 15, 2005