Co-production of hydrogen and electricity in a high temperature electrochemical system

• US 20040202914A1
• Filed: 05/29/2003
• Published: 10/14/2004
• Est. Priority Date: 04/09/2003
• Status: Active Grant

• Current Assignee: Bloom Energy Corporation
• Original Assignee: Bloom Energy Corporation
• Inventors: Gottmann, Matthias, McElroy, James F., Sridhar, K.R., Mitlitsky, Fred, Finn, John E.
• Granted Patent: US 7,482,078 B2
• Time in Patent Office: Days
• US Class Current: 429/34
• CPC Class Codes: C01B 2203/0205 containing a reforming step
• CPC Class Codes: C01B 2203/0283 containing a CO-shift step, i.e. a water gas shift step
• CPC Class Codes: C01B 2203/0405 Purification by membrane separation
• CPC Class Codes: C01B 2203/043 Regenerative adsorption process in two or more beds, one for adsorption, the other for regeneration
• CPC Class Codes: C01B 2203/0475 the impurity being carbon dioxide
• CPC Class Codes: C01B 2203/067 the reforming process taking place in the fuel cell
• CPC Class Codes: C01B 2203/1241 Natural gas or methane
• 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 3/34 by reaction of hydrocarbons with gasifying agents
• CPC Class Codes: C01B 3/342 with the aid of electrical means, electromagnetic or mechanical vibrations, or particle radiations
• CPC Class Codes: C01B 3/48 followed by reaction of water vapour with carbon monoxide
• CPC Class Codes: C10J 2300/093 Coal
• CPC Class Codes: C10J 2300/0969 Carbon dioxide
• CPC Class Codes: C10J 2300/1646 integrated with a fuel cell
• CPC Class Codes: C10J 3/463 in stationary fluidised beds
• CPC Class Codes: C25B 1/02 Hydrogen or oxygen
• CPC Class Codes: H01M 2008/1293 Fuel cells with solid oxide electrolytes
• CPC Class Codes: H01M 2008/147 Fuel cells with molten carbonates
• CPC Class Codes: H01M 2250/20 Fuel cells in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H01M 8/04022 Heating by combustion
• CPC Class Codes: H01M 8/04208 : Cartridges, cryogenic media or cryogenic reservoirs
• CPC Class Codes: H01M 8/04753 : of fuel cell reactants
• CPC Class Codes: H01M 8/04761 : of fuel cell exhausts
• CPC Class Codes: H01M 8/0491 : of fuel cell stacks
• CPC Class Codes: H01M 8/0494 : of fuel cell stacks
• CPC Class Codes: H01M 8/0612 : from carbon-containing material
• CPC Class Codes: H01M 8/0625 : in a modular combined reactor/fuel cell structure
• CPC Class Codes: H01M 8/0637 : Direct internal reforming at the anode of the fuel cell
• CPC Class Codes: H01M 8/0662 : Treatment of gaseous reactants or gaseous residues, e.g. cleaning
• CPC Class Codes: H01M 8/186 : by electrolytic decomposition of the electrolytic solution or the formed water product
• CPC Class Codes: Y02E 60/50 : Fuel cells
• CPC Class Codes: Y02P 30/00 : Technologies relating to oil refining and petrochemical industry
• CPC Class Codes: Y02T 90/40 : Application of hydrogen technology to transportation, e.g. using fuel cells

Abstract

A high temperature electrochemical system, such as a solid oxide fuel cell system, generates hydrogen and optionally electricity in a fuel cell mode. At least a part of the generated hydrogen is separated and stored or provided to a hydrogen using device. A solid oxide regenerative fuel cell system stores carbon dioxide in a fuel cell mode. The system generates a methane fuel in an electrolysis mode from the stored carbon dioxide and water by using a Sabatier subsystem. Alternatively, the system generates a hydrogen fuel in an electrolysis mode from water alone.

Claims

1. A high temperature electrochemical system, comprising:

a high temperature fuel cell;

a carbon containing fuel source;

a hydrogen separator which is adapted to separate at least a portion of hydrogen from a fuel side exhaust stream while the fuel cell operates in a fuel cell mode; and

a hydrogen storage/use subsystem operatively connected to the hydrogen separator which is adapted to store at least a portion of hydrogen received from the hydrogen separator or a hydrogen storage/use subsystem operatively connected to the hydrogen separator which is adapted to provide at least a portion of hydrogen received from the hydrogen separator to a hydrogen using device.

2. The system of claim 1, wherein the hydrogen separator is adapted to separate at least a portion of hydrogen while the fuel cell generates electricity in the fuel cell mode.

3. The system of claim 2, wherein the high temperature fuel cell comprises a molten carbonate fuel cell.

4. The system of claim 2, wherein the high temperature fuel cell comprises a solid oxide fuel cell.

5. The system of claim 1, wherein the high temperature fuel cell comprises a solid oxide fuel cell.

6. The system of claim 1, further comprising a hydrogen conditioner which is adapted to receive at least a portion of hydrogen from the hydrogen separator, to condition the hydrogen and to provide the conditioned hydrogen to the hydrogen storage/use subsystem.

7. The system of claim 2, further comprising a control unit which is adapted to control a variable amount of hydrogen separated by the hydrogen separator based on predetermined criteria or based on received data.

8. The system of claim 7, wherein the control unit is adapted to control a variable ratio of an amount of electricity generated to an amount of hydrogen separated by the hydrogen separator.

9. The system of claim 8, wherein the control unit is adapted to control the ratio of electricity generated to hydrogen separated by varying at least one of an amount of current drawn from the fuel cell and the amount of fuel being provided into the fuel cell.

10. The system of claim 1, wherein the hydrogen storage/use subsystem comprises a hydrogen storage vessel.

11. The system of claim 1, wherein the hydrogen storage/use subsystem comprises a second fuel cell which uses hydrogen fuel provided from the hydrogen separator.

12. The system of claim 11, wherein the high temperature fuel cell is located in a stationary location and the second fuel cell is located in a vehicle.

13. The system of claim 1, wherein the hydrogen storage/use subsystem comprises a hydrogen conduit operatively connected to a hydrogen using device.

14. The system of claim 1, wherein the carbon containing fuel source comprises a methane or a natural gas source.

15. The system of claim 1, wherein the carbon containing fuel source comprises a non-hydrocarbon carbon containing fuel source.

16. The system of claim 1, further comprising a fuel preprocessor subsystem which is operatively connected to the carbon containing fuel source and to the fuel cell, and which is adapted to convert a natural gas fuel into methane fuel to be supplied into the fuel cell.

17. The system of claim 1, further comprising a fuel reformer which is operatively connected to the carbon containing fuel source and to the fuel cell, and which is adapted to reform a carbon and bound hydrogen containing fuel provided from the carbon containing fuel source and to provide a carbon containing and free hydrogen containing fuel to a fuel inlet of the fuel cell.

18. The system of claim 17, wherein the fuel reformer is thermally integrated with the fuel cell.

19. The system of claim 1, further comprising a water-gas shift reactor which is operatively connected to the fuel side exhaust of fuel cell and to the hydrogen separator, and which is adapted to convert at least a portion of water in the fuel side exhaust stream to hydrogen and to provide at least a portion of the hydrogen to the hydrogen separator.

20. The system of claim 1, further comprising a water supply connected to a fuel inlet of the fuel cell.

21. The system of claim 1, further comprising:

a first conduit which connects the hydrogen separator to a fuel inlet conduit; and

a valve which separates hydrogen flow from the hydrogen separator between the first conduit and the hydrogen storage/use subsystem.

22. The system of claim 1, further comprising:

a second hydrogen separator;

a first conduit which connects the second hydrogen separator to a fuel inlet conduit; and

a valve which separates the fuel side exhaust stream between the hydrogen separator and the second hydrogen separator.

23. The system of claim 1, wherein the hydrogen separator comprises a pressure swing adsorption hydrogen separator.

24. The system of claim 4, wherein the fuel cell is part of a fuel cell stack.

25. The system of claim 4, wherein the solid oxide fuel cell comprises a solid oxide regenerative fuel cell.

26. The system of claim 25, further comprising:

a carbon dioxide storage vessel;

a water source;

a methane storage vessel; and

a Sabatier subsystem;

wherein;

the solid oxide regenerative fuel cell is adapted to provide carbon dioxide into the carbon dioxide storage vessel in a fuel cell mode;

the solid oxide regenerative fuel cell is adapted to receive the carbon dioxide from the carbon dioxide storage vessel and water from the water source and to provide carbon monoxide and hydrogen into the Sabatier subsystem in an electrolysis mode; and

the Sabatier subsystem is adapted to generate methane and water vapor from the received carbon monoxide and hydrogen, and to provide the methane into the methane storage vessel.

27. A solid oxide electrochemical system, comprising:

a solid oxide fuel cell;

a carbon containing fuel source;

a hydrogen separator which is adapted to separate at least a portion of hydrogen from a fuel side exhaust stream while the fuel cell generates electricity and operates in the fuel cell mode; and

a hydrogen storage/use subsystem operatively connected to the hydrogen separator which is adapted to store at least a portion of hydrogen received from the hydrogen separator or a hydrogen storage/use subsystem operatively connected to the hydrogen separator which is adapted to provide at least a portion of hydrogen received from the hydrogen separator to a hydrogen using device.

28. The system of claim 27, further comprising a hydrogen conditioner which is adapted to receive at least a portion of hydrogen from the hydrogen separator, to condition the hydrogen and to provide the conditioned hydrogen to the hydrogen storage/use subsystem.

29. The system of claim 27, further comprising a control unit which is adapted to control a variable ratio of an amount of electricity generated to an amount of hydrogen separated by the hydrogen separator based on predetermined criteria or based on received data.

30. The system of claim 27, wherein the hydrogen storage/use subsystem comprises a hydrogen storage vessel.

31. The system of claim 27, wherein the hydrogen storage/use subsystem comprises a second fuel cell which uses hydrogen fuel provided from the hydrogen separator.

32. The system of claim 31, wherein the solid oxide fuel cell is located in a stationary location and the second fuel cell is located in a vehicle.

33. The system of claim 27, wherein the hydrogen storage/use subsystem comprises a hydrogen conduit operatively connected to a hydrogen using device.

34. The system of claim 27, wherein the carbon containing fuel source comprises a methane gas source, a natural gas source or a non-hydrocarbon carbon containing fuel source.

35. The system of claim 27, further comprising at least one of:

a fuel preprocessor subsystem which is operatively connected to the carbon containing fuel source and to the fuel cell, and which is adapted to convert a natural gas fuel into a methane fuel to be supplied into the fuel cell;

a fuel reformer which is operatively connected to the carbon containing fuel source and to the fuel cell, and which is adapted to reform a carbon and bound hydrogen containing fuel provided from the carbon containing fuel source and to provide a carbon containing and free hydrogen containing fuel to a fuel inlet of the fuel cell;

a water-gas shift reactor which is operatively connected to the fuel side exhaust of fuel cell and to the hydrogen separator, and which is adapted to convert at least a portion of water in the fuel side exhaust stream to hydrogen and to provide at least a portion of the hydrogen to the hydrogen separator; and

a water supply connected to a fuel inlet of the fuel cell.

36. The system of claim 27, further comprising:

a first conduit which connects the hydrogen separator to a fuel inlet conduit; and

a valve which separates hydrogen flow from the hydrogen separator between the first conduit and the hydrogen storage/use subsystem.

37. The system of claim 27, further comprising:

a second hydrogen separator;

a first conduit which connects the second hydrogen separator to a fuel inlet conduit; and

a valve which separates the fuel side exhaust stream between the hydrogen separator and the second hydrogen separator.

38. A high temperature fuel cell system, comprising:

a first means for generating a fuel side exhaust stream from a carbon containing fuel inlet stream and an oxidizer inlet stream by oxygen ion conduction;

a second means for separating at least a portion of the hydrogen from the fuel side exhaust stream during generation of electricity by the first means; and

a third means for storing at least a portion of the separated hydrogen or a third means for providing at least a portion of the separated hydrogen to a hydrogen using device.

39. The system of claim 38, further comprising a fourth means for conditioning hydrogen received from the first means and for providing the conditioned hydrogen to the third means.

40. The system of claim 38, further comprising a fifth means for controlling a variable amount of hydrogen separated by the second means based on predetermined criteria or based on received data.

41. The system of claim 40, wherein the fifth means controls a variable ratio of an amount of electricity generated to an amount of hydrogen separated by the second means.

42. The system of claim 38, wherein the third means is a means for storing hydrogen.

43. The system of claim 38, wherein the third means is a means for providing the separated hydrogen to the hydrogen using device.

44. The system of claim 38, further comprising a sixth means for receiving separated hydrogen from the second means and for recirculating the separated hydrogen into a fuel inlet gas stream.

45. The system of claim 44, further comprising a seventh means for controlling an amount of hydrogen provided to the third means and to the sixth means by separating the fuel side exhaust stream into two portions or by dividing the separated hydrogen into two portions.

46. The system of claim 38, wherein the first means is a means for reversibly operating in a fuel cell mode and in an electrolysis mode.

47. The system of claim 46, wherein:

the first means provides carbon dioxide into a carbon dioxide storage vessel in a fuel cell mode;

the first means receives carbon dioxide and water, and provides carbon monoxide and hydrogen into a seventh means in an electrolysis mode; and

the seventh means is a means for generating methane and water vapor from the received carbon monoxide and hydrogen, and for providing the methane into a methane storage vessel.

48. The system of claim 38, wherein the fuel inlet stream comprises a methane gas stream, a natural gas stream or a non-hydrocarbon carbon containing fuel stream.

49. The system of claim 38, wherein the third means comprises a second fuel cell which uses hydrogen fuel provided from the second means.

50. The system of claim 38, further comprising at least one of:

an eighth means for converting a natural gas fuel into a methane fuel supplied into the first means;

a ninth means for reforming a carbon and bound hydrogen containing fuel into a carbon containing and free hydrogen containing fuel provided into the first means;

a tenth means for converting at least a portion of water in the fuel side exhaust stream to hydrogen and for providing at least a portion of the hydrogen to the second means; and

an eleventh means for providing water into the first means.

51. A method of producing hydrogen, comprising:

providing a carbon containing fuel and an oxidizer into a high temperature fuel cell;

generating a fuel side exhaust stream from the fuel cell while the fuel and the oxidizer are provided into the fuel cell operating in a fuel cell mode;

separating at least a portion of hydrogen from the fuel side exhaust stream during the fuel cell mode; and

providing at least a portion of the separated hydrogen to a hydrogen storage vessel or to a hydrogen using device.

52. The method of claim 51, further comprising generating electricity during the step of separating at least a portion of hydrogen.

53. The method of claim 52, wherein the high temperature fuel cell comprises a molten carbonate fuel cell.

54. The method of claim 52, wherein the high temperature fuel cell comprises a solid oxide fuel cell.

55. The method of claim 51, wherein the high temperature fuel cell comprises a solid oxide fuel cell.

56. The method of claim 51, further comprising conditioning the separated hydrogen and providing the conditioned hydrogen to the hydrogen storage vessel or to the hydrogen using device.

57. The method of claim 52, further comprising controlling a variable amount of separated hydrogen based on predetermined criteria or based on received data.

58. The method of claim 57, further comprising controlling a variable ratio of an amount of electricity generated to an amount of separated hydrogen.

59. The method of claim 58, wherein 20 to 50% of the fuel provided into the fuel cell is utilized for hydrogen production.

60. The method of claim 57, wherein the ratio is controlled by varying at least one of an amount of current drawn from the fuel cell and the amount of fuel being provided into the fuel cell.

61. The method of claim 51, wherein no or minimum amount of electricity is generated in the fuel cell mode during the step of separating at least a portion of hydrogen.

62. The method of claim 51, wherein the separated hydrogen is provided to a hydrogen storage vessel.

63. The method of claim 51, wherein the separated hydrogen is provided to a hydrogen using device.

64. The method of claim 63, wherein the hydrogen using device comprises a second fuel cell.

65. The method of claim 51, further comprising recirculating a portion of the separated hydrogen into a fuel inlet gas stream.

66. The method of claim 65, further comprising using a first hydrogen separator to recirculate a portion of the separated hydrogen into a fuel inlet gas stream and using a second hydrogen separator to provide the separated hydrogen to the hydrogen storage vessel or to the hydrogen using device.

67. The method of claim 51, wherein the solid oxide fuel cell is a solid oxide regenerative fuel cell which acts as a power generator and a hydrocarbon fuel reformer in the fuel cell mode.

68. The method of claim 67, further comprising:

providing carbon dioxide from the solid oxide regenerative fuel cell into a carbon dioxide storage vessel when the solid oxide regenerative fuel cell operates in a fuel cell mode;

providing the carbon dioxide from the carbon dioxide storage vessel and water from a water source into the solid oxide regenerative fuel cell and providing carbon monoxide and hydrogen from the solid oxide regenerative fuel cell into a Sabatier subsystem when the solid oxide regenerative fuel cell operates in an electrolysis mode;

generating methane and water vapor in the Sabatier subsystem from the received carbon monoxide and hydrogen; and

providing the methane into a methane storage vessel.

69. The method of claim 51, wherein the fuel comprises a methane or a natural gas fuel.

70. The method of claim 51, wherein the fuel comprises at least 50% non-hydrocarbon carbon containing fuel.

71. The method of claim 51, further comprising converting a natural gas fuel into a methane fuel and providing the methane fuel into the fuel cell.

72. The method of claim 51, further comprising reforming a carbon and bound hydrogen containing fuel to a carbon containing and free hydrogen containing fuel and providing the carbon containing and free hydrogen containing fuel into the fuel cell.

73. The method of claim 51, further comprising converting at least a portion of water in the fuel side exhaust stream to hydrogen and providing at least a portion of the converted hydrogen to the hydrogen storage vessel or to the hydrogen using device.

74. The method of claim 51, further comprising providing water together with the fuel into a fuel inlet of the fuel cell.

75. A method of producing hydrogen, comprising:

providing a carbon containing fuel and an oxidizer into a solid oxide fuel cell;

generating electricity and a fuel side exhaust stream from the fuel cell while the fuel and the oxidizer are provided into the fuel cell;

separating at least a portion of hydrogen from the fuel side exhaust stream during generation of electricity; and

providing at least a portion of the separated hydrogen to a hydrogen storage vessel or to a hydrogen using device.

76. The method of claim 75, further comprising controlling a variable ratio of an amount of electricity generated to an amount of separated hydrogen based on predetermined criteria or based on received data.

77. The method of claim 75, wherein the separated hydrogen is provided to a hydrogen storage vessel.

78. The method of claim 75, wherein the separated hydrogen is provided to a hydrogen using device.

79. The method of claim 75, further comprising recirculating a portion of the separated hydrogen into a fuel inlet gas stream.

80. The method of claim 75, wherein the step of providing a carbon containing fuel comprises providing a hydrocarbon fuel into the fuel cell and reforming the hydrocarbon fuel in the fuel cell.

81. The method of claim 75, wherein the step of providing a carbon containing fuel comprises:

providing a hydrocarbon fuel into a reformer which is thermally integrated with the fuel cell;

reforming the hydrocarbon fuel in the reformer; and

introducing the reformed fuel into the fuel cell.