Hybrid reformer for fuel flexibility

• US 7,704,617 B2
• Filed: 04/02/2007
• Issued: 04/27/2010
• Est. Priority Date: 04/03/2006
• Status: Active Grant

• Current Assignee: Bloom Energy Corporation
• Original Assignee: Bloom Energy Corporation
• Inventors: Venkataraman, Swaminathan
• Primary Examiner(s): Kalafut; Stephen J.
• Application Number:
  US11/730,529
• Publication Number:
  US 20070231631A1
• Time in Patent Office: 1,121 Days
• Field of Search: 429/17, 429/19, 429/20, 429/30, 422/190, 422/191
• US Class Current: 429/423
• CPC Class Codes: C01B 2203/0227 containing a catalytic reforming step
• CPC Class Codes: C01B 2203/066 with fuel cells
• CPC Class Codes: C01B 2203/0811 by combustion of fuel
• CPC Class Codes: C01B 2203/1052 Nickel or cobalt catalysts
• CPC Class Codes: C01B 2203/107 Platinum catalysts
• CPC Class Codes: C01B 2203/1205 Composition of the feed
• CPC Class Codes: C01B 2203/1235 Hydrocarbons
• CPC Class Codes: C01B 2203/142 At least two reforming, decomposition or partial oxidation steps in series
• CPC Class Codes: C01B 3/382 Multi-step processes
• CPC Class Codes: H01M 2008/1293 Fuel cells with solid oxide electrolytes
• CPC Class Codes: H01M 8/0247 characterised by the form characterised by a channel configuration H01M8/0258
• CPC Class Codes: H01M 8/04022 Heating by combustion
• CPC Class Codes: H01M 8/04097 with recycling of the reactants H01M8/04119, H01M8/04104 take precedence
• CPC Class Codes: H01M 8/0625 in a modular combined reactor/fuel cell structure
• CPC Class Codes: H01M 8/0631 Reactor construction specially adapted for combination reactor/fuel cell hydrogen C01B3/00; reactors for physicochemical processes B01J19/00
• CPC Class Codes: H01M 8/0662 Treatment of gaseous reactants or gaseous residues, e.g. cleaning
• CPC Class Codes: H01M 8/2425 High-temperature cells with solid electrolytes
• CPC Class Codes: H01M 8/2465 Details of groupings of fuel cells
• CPC Class Codes: H01M 8/2475 Enclosures, casings or containers of fuel cell stacks
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y02P 20/52 : using catalysts, e.g. selective catalysts

Abstract

A reformer for a fuel cell system includes a leading segment and a trailing segment. The leading segment includes less reactive catalyst and/or more stabilizing catalyst than the trailing segment. The reformer may be used for reformation of high and low hydrocarbon fuels.

Claims

1. A reformer for a fuel cell system, comprising a leading segment and a trailing segment, wherein:

the leading segment comprises less reactive catalyst than the trailing segment;

the reactive catalyst comprises nickel;

a rhodium stabilizing catalyst is located in the reformer; and

the leading segment of the reformer contains a substantially equal amount or concentration of the rhodium stabilizing catalyst compared to the trailing segment.

2. The reformer of claim 1, wherein the leading segment contains a lower amount of nickel than the trailing segment.

3. The reformer of claim 1, wherein the leading segment contains a lower nickel concentration than the trailing segment.

4. The reformer of claim 1, wherein nickel amount or concentration increases between the leading segment and the trailing segment in a single step or in a graded fashion.

5. A fuel cell system, comprising:

the reformer of claim 1; and

at least one fuel cell stack.

6. The system of claim 5, wherein:

the at least one fuel cell stack comprises an internal or an external reformation type solid oxide fuel cells;

the reformer comprises an external reformer; and

the reformer is thermally integrated with the at least one fuel cell stack.

7. The system of claim 6, further comprising a burner which is thermally integrated with the reformer.

8. The system of claim 5, further comprising a high hydrocarbon fuel source and a low hydrocarbon fuel source which are fluidly connected to the leading segment of the reformer.

9. The system of claim 8, wherein the high hydrocarbon fuel source comprises a diesel or jet fuel source, and the low hydrocarbon fuel source comprises a natural gas, methane, propane, ethanol or methanol fuel source.

10. A method of reforming different fuels, comprising:

providing a reformer comprising a leading segment and a trailing segment, wherein the leading segment comprises less reactive catalyst than the trailing segment;

providing a high hydrocarbon fuel into the reformer, such that the fuel passes through the leading segment before the trailing segment;

providing a reformate of the high hydrocarbon fuel into a fuel cell stack;

providing a low hydrocarbon fuel into the reformer, such that the fuel passes through the leading segment before the trailing segment; and

providing a reformate of the low hydrocarbon fuel into a fuel cell stack.

11. The method of claim 10, wherein the reactive catalyst comprises nickel.

12. The method of claim 11, wherein the leading segment contains a lower amount of nickel than the trailing segment.

13. The method of claim 11, wherein the leading segment contains a lower nickel concentration than the trailing segment.

14. The method of claim 10, wherein:

the reformer comprises an external reformer;

the fuel cell stack comprises an internal or an external reformation type solid oxide fuel cells; and

the reformer is thermally integrated with the fuel cell stack.

15. The method of claim 11, wherein:

nickel amount or concentration increases between the leading segment and the trailing segment in a single step or in a graded fashion;

a rhodium stabilizing catalyst is located in the reformer; and

the leading segment of the reformer contains a substantially equal or higher amount or concentration of the rhodium stabilizing catalyst compared to the trailing segment.

16. A fuel cell system, comprising:

at least one fuel cell stack;

a reformer comprising a leading segment and a trailing segment, wherein the leading segment comprises less reactive catalyst than the trailing segment; and

a high hydrocarbon fuel source and a low hydrocarbon fuel source which are fluidly connected to the leading segment of the reformer.

17. The system of claim 16, wherein the reactive catalyst comprises nickel.

18. The system of claim 17, wherein the leading segment contains a lower amount of nickel than the trailing segment.

19. The system of claim 17, wherein the leading segment contains a lower nickel concentration than the trailing segment.

20. The system of claim 17, wherein nickel amount or concentration increases between the leading segment and the trailing segment in a single step or in a graded fashion.

21. The system of claim 17, wherein:

a rhodium stabilizing catalyst is located in the reformer; and

the leading segment of the reformer contains a substantially equal amount or concentration of the rhodium stabilizing catalyst compared to the trailing segment.

22. The system of claim 17, wherein:

a rhodium stabilizing catalyst is located in the reformer; and

the leading segment of the reformer comprises more of the rhodium stabilizing catalyst than the trailing segment.

23. The system of claim 16, wherein:

the at least one fuel cell stack comprises an internal or an external reformation type solid oxide fuel cells;

the reformer comprises an external reformer; and

the reformer is thermally integrated with the at least one fuel cell stack.

24. The system of claim 23, further comprising a burner which is thermally integrated with the reformer.

25. The system of claim 16, wherein the high hydrocarbon fuel source comprises a diesel or jet fuel source, and the low hydrocarbon fuel source comprises a natural gas, methane, propane, ethanol or methanol fuel source.