HYDROGEN-PRODUCING FUEL PROCESSING ASSEMBLIES, HEATING ASSEMBLIES, AND METHODS OF OPERATING THE SAME

• US 20070274904A1
• Filed: 05/21/2007
• Published: 11/29/2007
• Est. Priority Date: 05/23/2006
• Status: Active Grant

• Current Assignee: DCNS SA (Government of France)
• Original Assignee: IdaTech LLC (IdaTech Ltd.)
• Inventors: Scharf, Mesa, Renn, Curtiss, Popham, Vernon Wade, Taylor, Kyle
• Granted Patent: US 7,939,051 B2
• Time in Patent Office: Days
• US Class Current: 423/652
• CPC Class Codes: B01J 2208/00398 inside the reactor bed
• CPC Class Codes: B01J 2208/00415 electric resistance heaters
• CPC Class Codes: B01J 2208/00504 by means of a burner
• CPC Class Codes: B01J 2208/00646 Means for starting up the reaction
• CPC Class Codes: B01J 2208/00716 Means for reactor start-up
• CPC Class Codes: B01J 8/0426 the beds being superimposed one above the other
• CPC Class Codes: B01J 8/0496 Heating or cooling the reactor
• CPC Class Codes: C01B 2203/0233 the reforming step being a steam reforming step
• CPC Class Codes: C01B 2203/04 containing a purification step for the hydrogen or the synthesis gas
• CPC Class Codes: C01B 2203/06 Integration with other chemical processes
• CPC Class Codes: C01B 2203/0811 by combustion of fuel
• CPC Class Codes: C01B 2203/085 by electric heating
• CPC Class Codes: C01B 2203/0866 by combination of different heating methods
• CPC Class Codes: C01B 2203/1288 Evaporation of one or more of the different feed components
• CPC Class Codes: C01B 2203/146 At least two purification steps in series
• CPC Class Codes: C01B 2203/1604 Starting up the process
• CPC Class Codes: C01B 3/382 Multi-step processes
• CPC Class Codes: C01B 3/384 the catalyst being continuously externally heated

Abstract

Hydrogen-producing fuel processing assemblies, including steam reforming fuel processing assemblies, startup assemblies for use therein, and methods of operating the same. In some embodiments, the startup assemblies include a startup reforming region that is upstream from a primary, or second, hydrogen-producing reforming region. In some embodiments, the startup reforming region and primary reforming regions are both steam reforming regions. In some embodiments, the startup assembly further includes at least one of a vaporization region and a startup heating assembly. In some embodiments, the startup heating assembly is an electrically powered heating assembly, and the fuel processing assembly further includes a (primary) heating assembly that combusts a byproduct stream from the fuel processing assembly to produce a combustion exhaust stream. In some embodiments, the startup reforming region is adapted to produce a gaseous output stream that will remain a gas-phase stream even if cooled below a minimum hydrogen-producing temperature.

Claims

1. A steam reforming hydrogen generation assembly, comprising:

a feedstock delivery system adapted to provide at least one feed stream containing water and a carbon-containing feedstock, wherein the feedstock delivery system provides the at least one feed stream as at least one liquid-containing feed stream; and

a hydrogen-producing fuel processing assembly, comprising;

a startup assembly adapted to receive the at least one feed stream from the feedstock delivery system and to covert the at least one feed stream to a gas-phase output stream containing hydrogen gas, wherein the startup assembly comprises;

a vaporization region adapted to receive and vaporize at least a portion of the at least one feed stream; and

a startup reforming region adapted to receive the at least one feed stream from the vaporization region and to produce via chemical reaction the output stream, wherein the output stream has a different composition than the at least one feed stream;

a hydrogen-producing region containing a reforming catalyst and adapted to receive the output stream from the startup reforming region and to produce therefrom via a steam reforming reaction a reformate stream containing hydrogen gas as a majority component, and other gases; and

a heating assembly adapted to combust a fuel stream to produce a heated exhaust stream for heating at least the hydrogen-producing region to at least a minimum hydrogen-producing temperature.

2. The hydrogen generation assembly of claim 1, wherein at least a substantial portion of the carbon-containing feedstock is chemically reacted in the startup reforming region.

3. The hydrogen generation assembly of claim 2, wherein all of the carbon-containing feedstock is chemically reacted in the startup reforming region.

4. The hydrogen generation assembly of claim 2, wherein the output stream is a gas-phase stream that contains only components that remain gas-phase components even if cooled to less than the minimum hydrogen-producing temperature, wherein the startup assembly further comprises a startup heating assembly that is adapted to heat at least one of the vaporization region and the startup reforming region.

5. The hydrogen generation assembly of claim 2, wherein the startup heating assembly is adapted to heat the vaporization region to a sufficient temperature for vaporizing a liquid portion of the at least one feed stream.

6. The hydrogen generation assembly of claim 2, wherein the startup heating assembly is adapted to heat the startup reforming region to at least a minimum hydrogen-producing temperature for producing hydrogen gas from the at least one feed stream via a steam reforming reaction.

7. The hydrogen generation assembly of claim 2, wherein the startup heating assembly is an electrically powered heating assembly.

8. The hydrogen generation assembly of claim 7, wherein the vaporization region and the startup reforming region define a passage into which the startup heating assembly extends.

9. The hydrogen generation assembly of claim 2, wherein the vaporization region and the startup reforming region are housed in a common shell upstream from the hydrogen-producing region.

10. The hydrogen generation assembly of claim 1, wherein the heating assembly is adapted to receive at least a portion of the reformate stream as the fuel stream.

11. The hydrogen generation assembly of claim 10, wherein the heating assembly is a gas burner that receives only the portion of the reformate stream as the fuel stream.

12. The hydrogen generation assembly of claim 10, wherein the heating assembly is adapted to heat at least the startup reforming region and the hydrogen-producing region to at least a minimum hydrogen-producing temperature for producing hydrogen gas via a steam reforming reaction.

13. The hydrogen generation assembly of claim 1, wherein the fuel processing assembly further comprises at least one purification region that is adapted to receive the reformate stream and to produce a hydrogen-rich stream and a byproduct stream therefrom, wherein the hydrogen-rich stream contains at least one of a greater concentration of hydrogen gas and a lower concentration of at least one of the other gases than the reformate stream, and further wherein the byproduct stream contains a greater concentration of at least one of the other gases than the reformate stream.

14. The hydrogen generation assembly of claim 13, wherein the at least one purification region includes at least one hydrogen-selective membrane.

15. The hydrogen generation assembly of claim 13, wherein the at least one purification region includes at least one chemical carbon monoxide removal assembly.

16. The hydrogen generation assembly of claim 13, wherein the at least one purification region and the hydrogen-producing region are housed in a common shell downstream from the startup assembly.

17. The hydrogen generation assembly of claim 1, wherein the hydrogen-producing region contains more reforming catalyst than the startup reforming region.

18. The hydrogen generation assembly of claim 1, wherein the hydrogen-producing region contains less reforming catalyst than the startup reforming region.

19. The hydrogen generation assembly of claim 1, in combination with a fuel cell stack that is adapted to receive at least a portion of the hydrogen gas produced by the fuel processing assembly.

20. A method for producing hydrogen gas via a steam reforming reaction, the method comprising:

heating a startup assembly comprising a vaporization region and a startup reforming region;

delivering a liquid feed stream that contains water and a carbon-containing feedstock to the startup assembly;

vaporizing the liquid feed stream and producing an output stream therefrom in the startup assembly, wherein the output stream is a gas-phase stream that contains hydrogen gas and has a different composition than the feed stream;

delivering the output stream to a hydrogen-producing region that comprises a steam reforming catalyst;

producing a reformate stream from the output stream;

wherein the reformate stream contains hydrogen gas as a majority component and other gases;

separating the reformate stream into a hydrogen-rich stream, which contains a greater concentration of hydrogen gas than the reformate stream, and a byproduct stream, which contains a greater concentration of the other gases than the reformate stream; and

combusting the byproduct stream to produce a heated exhaust stream for heating the startup assembly and the hydrogen-producing region.

21. The method of claim 20, wherein the heating includes electrically heating the startup assembly.

22. The method of claim 20, wherein the startup assembly includes a first housing containing the vaporization region and the startup reforming region.

23. The method of claim 20, wherein the hydrogen-producing region is contained in a second housing that is separate from the first housing.

24. The method of claim 20, wherein the output stream does not contain any of the carbon-containing feedstock.

25. The method of claim 20, wherein the output stream is a gas-phase stream.

26. The method of claim 20, wherein the method further comprises producing an electrical output from a portion of the hydrogen-rich stream.

27. The method of claim 20, wherein the hydrogen-producing region and the startup reforming region contain different amounts of stream reforming catalyst.

28. The method of claim 20, wherein the hydrogen-producing region and the startup reforming region contain the same amount of steam reforming catalyst.

29. The method of claim 20, wherein the method further comprises chemically reacting at least a portion of any carbon monoxide in the hydrogen-rich stream.