Methods and systems for pressure swing regeneration for hydrogen generation

• US 6,942,719 B2
• Filed: 06/30/2003
• Issued: 09/13/2005
• Est. Priority Date: 06/30/2003
• Status: Expired due to Term

• Current Assignee: Gas Technology Institute
• Original Assignee: The Boeing Co.
• Inventors: Stewart, Albert E.
• Primary Examiner(s): Spitzer, Robert H.
• Application Number:
  US10/609,940
• Publication Number:
  US 20040261617A1
• Time in Patent Office: 806 Days
• Field of Search: 95/96, 951/06, 951/07, 951/14, 951/15, 951/39, 423/220, 423/230, 502/20, 502/53, 502/56
• US Class Current: 95/106
• CPC Class Codes: C01B 2203/0233 the reforming step being a steam reforming step
• CPC Class Codes: C01B 2203/0283 containing a CO-shift step, i.e. a water gas shift step
• CPC Class Codes: C01B 2203/0425 In-situ adsorption process during hydrogen production
• CPC Class Codes: C01B 2203/0475 the impurity being carbon dioxide
• CPC Class Codes: C01B 2203/148 involving a recycle stream to the feed of the process for making hydrogen or synthesis gas
• CPC Class Codes: C01B 3/38 using catalysts
• CPC Class Codes: C01B 3/56 by contacting with solids; Regeneration of used solids C01B3/508 takes precedence

Abstract

Methods and systems for pressure swing absorption for hydrogen generation are presented. In one embodiment, a method includes absorbing at least one oxide of carbon with a pressure swing absorber from a steam reformation of methane. The steam reformation may occur at an ambient pressure in excess of 300 psia and at an ambient temperature in excess of 600° centigrade. The steam reformation of methane produces a stream of product gas. The steam reformation of methane is interrupted allowing the regenerating of the pressure swing absorber at an ambient pressure of less than 10 psia and at an ambient temperature sufficient to calcine the pressure swing absorber to exude carbon dioxide.

Claims

1. A method of pressure swing absorption, the method comprising:

absorbing at least one oxide of carbon with a pressure swing absorber from a steam reformation of methane, producing a stream of product gas;

interrupting the steam reformation of methane; and

regenerating the pressure swing absorber at an ambient pressure of less than or approximately equal to 10 psia and at an ambient temperature sufficient to calcine the pressure swing absorber to exude carbon dioxide.

2. The method of claim 1, wherein absorbing at least one oxide of carbon includes absorbing at least one oxide of carbon with a pressure swing absorber from a steam reformation of methane at an ambient pressure in excess of 300 psia and at an ambient temperature in excess of 600°

centigrade.

3. The method of claim 2, further comprising monitoring at least one oxide of carbon present in the product stream.

4. The method of claim 3, wherein interrupting the steam reformation of methane includes interrupting the steam reformation responsive to an amount of the at least one monitored oxide of carbon.

5. The method of claim 1, wherein absorbing at least one oxide of carbon with a pressure swing absorber includes absorbing at least one oxide of carbon with a pressure swing absorber disposed in a bed.

6. The method of claim 5, wherein interrupting the steam reformation of methane includes redirecting the steam reformation of methane away from the bed.

7. The method of claim 6, wherein interrupting the steam reformation of methane includes removing the bed from the steam reformation of methane.

8. The method of claim 1, wherein absorbing the at least one oxide further comprises absorbing at least one oxide of carbon using a pressure swing absorber having granules with a diameter of about 50 microns.

9. The method of claim 8, wherein absorbing at least one oxide of carbon using a pressure swing absorber further comprises entraining the granules in the stream of product gas.

10. The method of claim 9, wherein absorbing at least one oxide of carbon using a pressure swing absorber further comprises entraining the granules in a feedstream of methane.

11. The method of claim 1, wherein the pressure swing absorber is calcium oxide.

12. A method for regenerating a pressure swing absorber, the method comprising:

adjusting an ambient pressure to less than 10 psia;

adjusting a temperature of the pressure swing absorber sufficient to calcine the pressure swing absorber to exude carbon dioxide; and

venting exuded carbon dioxide away from the pressure swing absorber.

13. The method of claim 12, wherein adjusting the temperature includes cooling the pressure swing absorber.

14. The method of claim 12, wherein adjusting a temperature of the pressure swing absorber further comprises adjusting the ambient pressure.

15. The method of claim 12, wherein adjusting a temperature of the pressure swing absorber further comprises adjusting a temperature of calcium oxide.

16. The method of claim 12, wherein adjusting a temperature of the pressure swing absorber further comprises adjusting a temperature of granules with a diameter of about 50 microns.

17. The method of claim 12, wherein the pressure swing absorber is present in a catalyst bed.

18. A method of absorbing carbonaceous gases in steam reformation of methane, the method comprising:

providing methane gas and steam in about stoichiometric portions for steam methane reformation;

absorbing carbonaceous gas with a pressure swing absorber, the pressure swing absorber adapted to at least partially remove at least one oxide of carbon in a steam reformation of methane to produce a product stream;

interrupting the provided methane gas and steam; and

regenerating the pressure swing absorber at an ambient pressure of less than 10 psia and at an ambient temperature sufficient to calcine the pressure swing absorber to exude carbon dioxide.

19. The method of claim 18, wherein providing methane gas and steam includes providing methane gas and steam at a pressure in excess of 300 psia and at a temperature in excess of 700°

centigrade.

20. The method of claim 18, further comprising monitoring of oxides of carbon present in the product stream.

21. The method of claim 18, wherein interrupting the provided methane gas and steam further comprises interrupting the methane gas and steam in response to a monitored amount of oxides of carbon.

22. The method of claim 18, wherein the pressure swing absorber is in a bed.

23. The method of claim 22, wherein the interrupting includes redirecting the steam reformation of methane away from the bed.

24. The method of claim 22, wherein the interrupting is by removing the bed from the steam reformation of methane.

25. The method of claim 18, wherein the pressure swing absorber includes granules with a diameter of about 50 microns.

26. The method of claim 25, wherein the pressure swing absorber is entrained in the stream of product gas.

27. The method of claim 26, wherein the pressure swing absorber is entrained in a feedstream of methane.

28. The method of claim 18, wherein the pressure swing absorber is calcium oxide.