Hydrogen producing fuel processing system

• US 6,221,117 B1
• Filed: 04/13/1999
• Issued: 04/24/2001
• Est. Priority Date: 10/30/1996
• Status: Expired due to Term

• Current Assignee: DCNS SA (Government of France)
• Original Assignee: IdaTech LLC (IdaTech Ltd.)
• Inventors: Edlund, David J., Pledger, William A.
• Primary Examiner(s): Tran, Hien
• Assistant Examiner(s): RIDLEY, BASIA ANNA
• Application Number:
  US09/291,447
• Time in Patent Office: 742 Days
• Field of Search: 481/97.R, 482/13, 482/14.A, 482/14.R, 482/15, 48/63, 48/76, 48/94, 48/95, 481/277, 95/56, 96/10, 96/11, 123/3, 208/66, 252/373, 422/196, 422/197, 422/193, 422/198, 423/395, 423/652, 429/17, 429/19, 502/210, 518/704, 518/708
• US Class Current: 48/76
• CPC Class Codes: B01J 19/2475 Membrane reactors
• CPC Class Codes: B01J 2208/00053 of the heat exchange medium
• CPC Class Codes: B01J 2208/00061 of the reactants
• CPC Class Codes: B01J 2208/00088 Flow rate measurement
• CPC Class Codes: B01J 2208/00106 by indirect heat exchange
• CPC Class Codes: B01J 2208/00132 Tubes
• CPC Class Codes: B01J 2208/00141 Coils
• CPC Class Codes: B01J 2208/00256 in a heat exchanger for the heat exchange medium separate from the reactor
• CPC Class Codes: B01J 2208/00309 with two or more reactions in heat exchange with each other, such as an endothermic reaction in heat exchange with an exothermic reaction
• CPC Class Codes: B01J 2208/00371 gaseous
• CPC Class Codes: B01J 2208/00415 electric resistance heaters
• CPC Class Codes: B01J 2208/00495 using insulating materials or refractories
• CPC Class Codes: B01J 2208/00504 by means of a burner
• CPC Class Codes: B01J 2208/0053 Controlling multiple zones along the direction of flow, e.g. pre-heating and after-cooling
• CPC Class Codes: B01J 2208/00539 Pressure
• CPC Class Codes: B01J 2208/00548 Flow
• CPC Class Codes: B01J 2219/00069 Flow rate measurement
• CPC Class Codes: B01J 2219/00081 Tubes
• CPC Class Codes: B01J 2219/00103 in a heat exchanger separate from the reactor
• CPC Class Codes: B01J 2219/00123 adding a temperature modifying medium to the reactants
• CPC Class Codes: B01J 2219/00135 : Electric resistance heaters
• CPC Class Codes: B01J 2219/00157 : by means of a burner
• CPC Class Codes: B01J 8/006 : by filtration
• CPC Class Codes: B01J 8/009 : Membranes, e.g. feeding or removing reactants or products to or from the catalyst bed through a membrane
• CPC Class Codes: B01J 8/0257 : in a cylindrical annular shaped bed
• CPC Class Codes: B01J 8/0285 : Heating or cooling the reactor for tubular reactors in furnaces B01J8/062
• CPC Class Codes: B01J 8/04 : the fluid passing successively through two or more beds
• CPC Class Codes: B01J 8/0465 : the beds being concentric
• CPC Class Codes: B01J 8/0469 : the beds being superimposed one above the other
• CPC Class Codes: B01J 8/0496 : Heating or cooling the reactor
• CPC Class Codes: B01J 8/062 : being installed in a furnace
• CPC Class Codes: B01J 8/067 : Heating or cooling the reactor B01J8/062 takes precedence
• CPC Class Codes: C01B 2203/0233 : the reforming step being a steam reforming step
• CPC Class Codes: C01B 2203/0244 : the reforming step being an autothermal reforming step, e.g. secondary reforming processes
• CPC Class Codes: C01B 2203/0261 : containing a catalytic partial oxidation step [CPO]
• CPC Class Codes: C01B 2203/0283 : containing a CO-shift step, i.e. a water gas shift step
• CPC Class Codes: C01B 2203/041 : In-situ membrane purification during hydrogen production
• CPC Class Codes: C01B 2203/044 : Selective oxidation of carbon monoxide
• CPC Class Codes: C01B 2203/0445 : Selective methanation
• CPC Class Codes: C01B 2203/047 : the impurity being carbon monoxide
• CPC Class Codes: C01B 2203/0475 : the impurity being carbon dioxide
• CPC Class Codes: C01B 2203/066 : with fuel cells
• CPC Class Codes: C01B 2203/0811 : by combustion of fuel
• CPC Class Codes: C01B 2203/0816 : Heating by flames
• CPC Class Codes: C01B 2203/0822 : the fuel containing hydrogen
• CPC Class Codes: C01B 2203/0827 : at least part of the fuel being a recycle stream
• CPC Class Codes: C01B 2203/0844 : the non-combustive exothermic reaction being another reforming reaction as defined in groups C01B2203/02 - C01B2203/0294
• 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 2203/0877 : by direct injection of fluid
• CPC Class Codes: C01B 2203/0883 : by indirect heat exchange
• CPC Class Codes: C01B 2203/1011 : Packed bed of catalytic structures, e.g. particles, packing elements
• CPC Class Codes: C01B 2203/1041 : Composition of the catalyst
• CPC Class Codes: C01B 2203/1058 : Nickel catalysts
• CPC Class Codes: C01B 2203/1076 : Copper or zinc-based catalysts
• CPC Class Codes: C01B 2203/1217 : Alcohols
• CPC Class Codes: C01B 2203/1223 : Methanol
• CPC Class Codes: C01B 2203/1235 : Hydrocarbons
• CPC Class Codes: C01B 2203/1241 : Natural gas or methane
• CPC Class Codes: C01B 2203/1247 : Higher hydrocarbons
• CPC Class Codes: C01B 2203/1258 : Pre-treatment of the feed
• CPC Class Codes: C01B 2203/1276 : Mixing of different feed components
• CPC Class Codes: C01B 2203/1282 : using static mixers
• CPC Class Codes: C01B 2203/1288 : Evaporation of one or more of the different feed components
• CPC Class Codes: C01B 2203/142 : At least two reforming, decomposition or partial oxidation steps in series
• 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 2203/1628 : Controlling the pressure
• CPC Class Codes: C01B 2203/1633 : Measuring the pressure
• CPC Class Codes: C01B 2203/1657 : the product being hydrogen
• CPC Class Codes: C01B 2203/1676 : Measuring the composition of the product
• CPC Class Codes: C01B 2203/169 : Controlling the feed
• CPC Class Codes: C01B 2203/1695 : Adjusting the feed of the combustion
• CPC Class Codes: C01B 2203/82 : Several process steps of C01B2203/02 - C01B2203/08 integrated into a single apparatus
• CPC Class Codes: C01B 3/323 : Catalytic reaction of gaseous or liquid organic compounds other than hydrocarbons with gasifying agents
• CPC Class Codes: C01B 3/38 : using catalysts
• CPC Class Codes: C01B 3/382 : Multi-step processes
• CPC Class Codes: C01B 3/501 : by diffusion
• CPC Class Codes: C01B 3/503 : characterised by the membrane
• CPC Class Codes: C01B 3/505 : Membranes containing palladium
• CPC Class Codes: C01B 3/586 : the reaction being a methanation reaction
• CPC Class Codes: C12F 5/00 : Preparation of denatured alcohol
• CPC Class Codes: H01M 8/0612 : from carbon-containing material
• 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: Y02E 60/50 : Fuel cells
• CPC Class Codes: Y02P 20/10 : Process efficiency

Abstract

A fuel processing system is disclosed. The system includes a steam reformer adapted to produce hydrogen from a feedstock consisting of water and at least one of an alcohol and a hydrocarbon feedstock. The hydrogen is produced by reacting the feedstock in the present of a reforming catalyst. The product stream is passed through a hydrogen-selective membrane module, at which the permeate stream is polished to remove trade carbon monoxide and carbon dioxide, and the byproduct stream is combusted to heat the reformer.

Claims

1. A steam reformer, comprising:

a shell having an outer surface;

a reforming region within the shell and including a reforming catalyst bed adapted to receive a reforming feedstock and convert the feedstock into a reformate stream comprising hydrogen, carbon monoxide and carbon dioxide;

a hydrogen purification module within the shell and including a hydrogen-selective membrane in fluid communication with the reforming catalyst bed and adapted to produce a permeate stream comprised of the portion of the reformate stream which passes through the membrane, and a byproduct stream comprised of the portion of the reformate stream which does not pass through the membrane;

a polishing catalyst bed within the shell and including a methanation catalyst, wherein the polishing catalyst bed is in fluid communication with the hydrogen purification module and is adapted to receive the permeate stream therefrom and produce a product stream from the permeate stream, wherein the polishing catalyst bed is adapted to reduce the concentration of carbon dioxide and carbon monoxide in the permeate stream by catalytic reaction to produce methane; and

a combustion chamber adapted to receive and combust a fuel stream with air to generate heat for heating the reformer, wherein the polishing catalyst bed is thermally coupled to the combustion chamber to be heated thereby.

2. The reformer of claim 1, wherein the polishing catalyst bed is fluidly isolated from the combustion chamber so that combustion fluid in the combustion chamber does not enter the polishing catalyst bed.

3. The reformer of claim 1, wherein the fuel stream is at least partially comprised of the byproduct stream.

4. The reformer of claim 1, wherein the polishing catalyst bed is located at least substantially within the combustion chamber.

5. The reformer of claim 1, wherein the combustion chamber receives air for supporting combustion from a cathode air stream discharged from a fuel cell.

6. The reformer of claim 1, wherein the combustion chamber includes an oxidation catalyst.

7. The reformer of claim 1, wherein the combustion chamber includes a burner.

8. The reformer of claim 1, wherein the reforming feedstock is preheated prior to passage into the reforming region by heat exchange with at least one of the product stream and an exhaust stream from the combustion chamber.

9. The reformer of claim 1, wherein the reforming feedstock is preheated prior to passage into the reforming region by countercurrent heat exchange with at least one of the product stream and an exhaust stream from the combustion chamber.

10. The reformer of claim 1, wherein the reformer is further adapted to receive a liquid-phase feedstock as the reforming feedstock and vaporize the liquid-phase feedstock prior to delivery to the reforming catalyst bed.

14. The reformer of claim 10, wherein the reformer includes a conduit through which the reforming feedstock is passed prior to delivery to the reforming catalyst bed, and further wherein while in the conduit, the reforming feedstock is maintained free from contact with the combustion chamber yet in thermal communication with the combustion chamber.

15. The reformer of claim 1, wherein the reformer includes a vaporization region within the shell through which the feedstock is received and vaporized prior to entering the reforming region.

16. The reformer of claim 15, wherein the vaporization region is maintained at a greater temperature than the reforming region.

17. The reformer of claim 15, wherein the vaporization region includes a mixing chamber through which a first vaporized component of the reforming feedstock is mixed with a second, at least partially liquid-phase component of the reforming feedstock.

18. The reformer of claim 17, wherein the mixing chamber includes means for promoting turbulent flow of the components through the mixing chamber.

19. The reformer of claim 1, wherein the reformer further includes a vaporization region through which the feedstock is received and vaporized prior to entering the reforming region, and further wherein the vaporization region is at least partially located external the shell while remaining in thermal communication with the shell.

20. The reformer of claim 1, wherein the reformer further includes a quenching chamber in fluid communication with the reforming region and the hydrogen purification module, wherein the quenching chamber is adapted to receive the reformate stream prior to entry to the hydrogen purification module and to reduce the temperature of the reformate stream by heat exchange with a cooler stream.

21. The reformer of claim 20, wherein the cooler stream is an air stream.

22. The reformer of claim 21, wherein the cooler stream is an air stream in fluid communication with the combustion chamber.

23. The reformer of claim 1, wherein the feedstock is comprised of water and at least one of an alcohol and a hydrocarbon.

24. The reformer of claim 1, wherein a portion of the reforming catalyst bed extends external the shell.

25. The reformer of claim 24, wherein the reforming region includes a plurality of reforming catalyst beds.

26. The reformer of claim 25, wherein the reformer further includes a distribution manifold adapted to receive the reforming feedstock and distribute the reforming feedstock to the plurality of reforming catalyst beds.

27. The reformer of claim 1, wherein the amount of hydrogen in the product stream is less than a stoichiometrically available amount of hydrogen.

28. The reformer of claim 27, wherein the amount of hydrogen in the product stream is between approximately 50% and approximately 80% of the stoichiometrically available hydrogen.

29. The reformer of claim 1, wherein the hydrogen-selective membrane is formed from at least one of palladium and a palladium alloy.

30. The reformer of claim 29, wherein the hydrogen-selective membrane contains less than 200 ppm carbon.

31. The reformer of claim 30, wherein the hydrogen-selective membrane contains less than 100 ppm carbon.

32. The reformer of claim 31, wherein the hydrogen-selective membrane contains less than 50 ppm carbon.

33. The reformer of claim 1, wherein the polishing catalyst bed further extends at least partially beyond the shell.

34. The reformer of claim 1, wherein the fuel stream is at least substantially comprised of the byproduct stream.

35. The reformer of claim 1, wherein the fuel stream is completely comprised of the byproduct stream.

11. The reformer of clam 10, wherein the reformer includes a conduit through which the reforming feedstock is passed prior to delivery to the reforming catalyst bed, and further wherein while in the conduit, the reforming feedstock is maintained free from contact with the reforming region yet in thermal communication with the reforming region.

12. The reformer of claim 11, wherein the conduit extends at least partially through the reforming catalyst bed.

13. The reformer of claim 11, wherein the conduit enables countercurrent heat exchange between the reforming feedstock and the reforming region.

36. A steam reformer, comprising:

a shell having an outer surface;

a reforming region within the shell and including a reforming catalyst bed adapted to receive a reforming feedstock and convert the feedstock into a reformate stream comprising hydrogen, carbon monoxide and carbon dioxide;

a hydrogen purification module within the shell and including a hydrogen-selective membrane in fluid communication with the reforming catalyst bed and adapted to produce a permeate stream comprised of the portion of the reformate stream which passes through the membrane, and a byproduct stream comprised of the portion of the reformate stream which does not pass through the membrane;

a polishing catalyst bed within the shell and including a methanation catalyst, wherein the polishing catalyst bed is in fluid communication with the hydrogen purification module and is adapted to receive the permeate stream therefrom and produce a product stream from the permeate stream, wherein the polishing catalyst bed is adapted to reduce the concentration of carbon dioxide and carbon monoxide in the permeate stream by catalytic reaction to produce methane; and

a combustion chamber adapted to receive and combust a fuel stream with air to generate heat for heating the reformer, wherein the combustion chamber receives air for supporting combustion from a cathode air stream discharged from a fuel cell.

37. The reformer of claim 36, wherein the polishing catalyst bed is fluidly isolated from the combustion chamber so that combustion fluid in the combustion chamber does not enter the polishing catalyst bed.

38. The reformer of claim 36, wherein the fuel stream is at least partially comprised of the byproduct stream.

39. The reformer of claim 36, wherein the polishing catalyst bed is located at least substantially within the combustion chamber.

40. The reformer of claim 36, wherein the combustion chamber includes an oxidation catalyst.

41. The reformer of claim 36, wherein the combustion chamber includes a burner.

42. The reformer of claim 36, wherein the reforming feedstock is preheated prior to passage into the reforming region by heat exchange with at least one of the product stream and an exhaust stream from the combustion chamber.

43. The reformer of claim 36, wherein the reforming feedstock is preheated prior to passage into to reforming region by countercurrent heat exchange with at least one of the product stream and an exhaust stream from the combustion chamber.

44. The reformer of claim 36, wherein the reformer is further adapted to receive a liquid-phase feedstock as the reforming feedstock and vaporize the liquid-phase feedstock prior to delivery to the reforming catalyst bed.

45. The reformer of claim 44, wherein the reformer includes a conduit through which the reforming feedstock is passed prior to delivery to the reforming catalyst bed, and filer wherein while in the conduit, the reforming feedstock is maintained free from contact with the reforming region yet in thermal communication with the reforming region.

46. The reformer of claim 45, wherein the conduit extends at least partially through the reforming catalyst bed.

47. The reformer of claim 45, wherein the conduit enables countercurrent heat exchange between the reforming feedstock and the reforming region.

48. The reformer of claim 44, wherein the reformer includes a conduit through which the reforming feedstock is passed prior to delivery to the reforming catalyst bed, and further wherein while in the conduit, the reforming feedstock is maintained free from contact with the combustion chamber yet in thermal communication with the combustion chamber.

49. The reformer of claim 36, wherein the reformer includes a vaporization region win the shell through which the feedstock is received and vaporized prior to entering the reforming region.

50. The reformer of claim 49, wherein the vaporization region is maintained at a greater temperature than the reforming region.

51. The reformer of claim 49, wherein the vaporization region includes a mixing chamber through which a first vaporized component of the reforming feedstock is mixed with a second, at least partially liquid-phase component of the reforming feedstock.

52. The reformer of claim 51, wherein the mixing chamber includes means for promoting turbulent flow of the components through the mixing chamber.

53. The reformer of claim 36, wherein the reformer further includes a vaporization region through which the feedstock is received and vaporized prior to entering the reforming region, and further wherein the vaporization region is at least partially located external the shell while remaining in thermal communication with the shell.

54. The reformer of claim 36, wherein the reformer further includes a quenching chamber in fluid communication with the reforming region and the hydrogen purification module, wherein the quenching chamber is adapted to receive the reformate stream prior to entry to the hydrogen purification module and to reduce the temperature of the reformate stream by heat exchange with a cooler stream.

55. The reformer of claim 54, wherein the cooler stream is an air stream.

56. The reformer of claim 55, wherein the cooler stream is an air stream in fluid communication with the combustion chamber.

57. The reformer of claim 36, wherein the feedstock is comprised of water and at least one of an alcohol and a hydrocarbon.

58. The reformer of claim 36, wherein a portion of the reforming catalyst bed extends external the shell.

59. The reformer of claim 58, wherein the reforming region includes a plurality of reforming catalyst beds.

60. The reformer of claim 59, wherein the reformer further includes a distribution manifold adapted to receive the reforming feedstock and distribute the reforming feedstock to the plurality of reforming catalyst beds.

61. The reformer of claim 36, wherein the amount of hydrogen in the product stream is less than a stoichiometrically available amount of hydrogen.

62. The reformer of claim 61, wherein the amount of hydrogen in the product stream is between approximately 50% and approximately 80% of the stoichiometrically available hydrogen.

63. The reformer of claim 36, wherein the hydrogen-selective membrane is formed from at least one of palladium and a palladium alloy.

64. The reformer of claim 63, wherein the hydrogen-selective membrane contains less than 200 ppm carbon.

65. The reformer of claim 64, wherein the hydrogen-selective membrane contains less than 100 ppm carbon.

66. The reformer of claim 65, wherein the hydrogen-selective membrane contains less than 50 ppm carbon.

67. The reformer of claim 36, wherein the polishing catalyst bed further extends at least partially beyond the shell.

68. The reformer of claim 36, wherein the fuel stream is at least substantially comprised of the byproduct stream.

69. The reformer of claim 36, wherein the fuel stream is completely comprised of the byproduct stream.