Method for the co-production of hydrogen and electricity in a high temperature electrochemical system

• US 8,071,241 B2
• Filed: 08/29/2008
• Issued: 12/06/2011
• Est. Priority Date: 04/09/2003
• Status: Active Grant

• Current Assignee: Bloom Energy Corporation
• Original Assignee: Bloom Energy Corporation
• Inventors: Sridhar, K. R., McElroy, James F., Finn, John E., Mitlitsky, Fred, Gottmann, Matthias
• Primary Examiner(s): Alejandro, Raymond
• Application Number:
  US12/230,486
• Publication Number:
  US 20080318092A1
• Time in Patent Office: 1,194 Days
• Field of Search: 429/408, 429/411, 429/415, 429/417, 429/418, 429/419, 429/443, 429/515, 429/472, 429/495, 205/343
• US Class Current: 429/408
• 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 method in which 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 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;

providing the fuel side exhaust stream to a hydrogen separator;

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

providing at least a first portion of the separated hydrogen from the hydrogen separator to a hydrogen storage vessel or to a hydrogen using device;

recycling at least a second portion of the separated hydrogen the hydrogen separator to the fuel cell; and

providing a remainder of the fuel side exhaust stream from the hydrogen separator as tail gas, and wherein the step of separating in the hydrogen separator at least the portion of hydrogen occurs prior to recycling a portion of the fuel side exhaust stream toward the fuel cell.

2. The method of claim 1, further comprising generating electricity during the step of separating at least a portion of hydrogen.

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

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

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

6. The method of claim 1, further comprising conditioning the separated hydrogen and providing the conditioned hydrogen to the hydrogen storage vessel or to the hydrogen using device.

7. The method of claim 2, further comprising controlling a variable amount of separated hydrogen based on predetermined criteria or based on received data.

8. The method of claim 7, further comprising controlling a variable ratio of an amount of electricity generated to an amount of separated hydrogen.

9. The method of claim 8, wherein 20 to 50% of the fuel provided into the fuel cell is utilized for hydrogen production.

10. The method of claim 7, 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.

11. The method of claim 1, wherein the separated hydrogen is provided to a hydrogen storage vessel.

12. The method of claim 1, wherein the separated hydrogen is provided to a hydrogen using device.

13. The method of claim 12, wherein the hydrogen using device comprises a second fuel cell.

14. The method of claim 1, further comprising recirculating a portion of the separated hydrogen into a fuel inlet gas stream.

15. The method of claim 14, 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.

16. The method of claim 1, 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.

17. The method of claim 16, 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.

18. The method of claim 1, wherein the fuel comprises a methane or a natural gas fuel.

19. The method of claim 1, wherein the fuel comprises at least 50% non-hydrocarbon carbon containing fuel.

20. The method of claim 1, further comprising converting a natural gas fuel into a methane fuel and providing the methane fuel into the fuel cell.

21. The method of claim 1, 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.

22. The method of claim 1, 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.

23. The method of claim 1, further comprising providing water together with the fuel into a fuel inlet of the fuel cell.

24. 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;

providing the fuel side exhaust stream to a hydrogen separator;

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

providing at least a first portion of the separated hydrogen from the hydrogen separator to a hydrogen storage vessel or to a hydrogen using device;

recycling at least a second portion of the separated hydrogen from the hydrogen separator to the fuel cell; and

providing a remainder of the fuel side exhaust stream from the hydrogen separator as tail gas, and wherein the step of separating in the hydrogen separator at least the portion of hydrogen occurs prior to recycling a portion of the fuel side exhaust stream toward the fuel cell.

25. The method of claim 24, 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.

26. The method of claim 24, wherein the separated hydrogen is provided to a hydrogen storage vessel.

27. The method of claim 24, wherein the separated hydrogen is provided to a hydrogen using device.

28. The method of claim 24, further comprising recirculating a portion of the separated hydrogen into a fuel inlet gas stream.

29. The method of claim 24, 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.

30. The method of claim 24, 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.