Power generator with additional hydrogen storage

• US 20080268303A1
• Filed: 04/25/2007
• Published: 10/30/2008
• Est. Priority Date: 04/25/2007
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Eickhoff, Steven J.
• Granted Patent: US 8,551,663 B2
• Time in Patent Office: Days
• US Class Current: 429/19
• CPC Class Codes: H01M 8/04201 Reactant storage and supply, e.g. means for feeding, pipes
• CPC Class Codes: H01M 8/04208 Cartridges, cryogenic media or cryogenic reservoirs
• CPC Class Codes: H01M 8/04216 characterised by the choice for a specific material, e.g. carbon, hydride, absorbent
• CPC Class Codes: H01M 8/065 by dissolution of metals or alloys; by dehydriding metallic substances
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

A power generator includes a hydrogen producing fuel and a hydrogen storage element. A fuel cell having a proton exchange membrane separates the hydrogen producing fuel from ambient. A valve is positioned between the hydrogen storage element and the hydrogen producing fuel and the fuel cell. Hydrogen is provided to the fuel cell from the hydrogen storage element if demand for electricity exceeds the hydrogen producing capacity of the hydrogen producing fuel.

Claims

1. A power generator comprising:

a hydrogen producing fuel;

a fuel cell having a proton exchange membrane separating the hydrogen producing fuel from ambient; and

a hydrogen storage element.

2. The power generator of claim 1 and further comprising a valve positioned between the hydrogen storage element and the hydrogen producing fuel and the fuel cell.

3. The power generator of claim 1 wherein the hydrogen storage element comprises a porous metal hydride hydrogen storage element.

4. The power generator of claim 3 wherein the storage element has an equilibrium pressure in the range of approximately 0.01 to 10 atmospheres.

5. The power generator of claim 4 wherein the equilibrium pressure in the range of approximately 0.01 to 10 atmospheres is over an approximately −

20 to 60°

C. temperature range.

6. The power generator of claim 1 wherein the hydrogen storage element comprises a metal hydride including at least one of an ab5 compound, ab2 compound, ab compound, complex alloys, intermetallic compounds or solid solution alloys.

7. The power generator of claim 1 wherein the hydrogen storage element comprises a material selected from the group consisting of LaNi₅, LaNi₄.6Mn_0.4, MnNi_3.5Co_0.7Al_0.8, MnNi₄.2Co_0.2Mn_0.3Al_0.3, TiFe_0.8Ni_0.2, CaNi₅, (V_0.9Ti_0.1)_0.95Fe_0.05, (V_0.9Ti_0.1)_0.95Fe_0.05, and LaNi_4.7Al_0.3.

8. The power generator of claim 1 and further comprising a hydrogen permeable particulate filter disposed between the hydrogen producing fuel and the hydrogen storage element.

9. The power generator of claim 1 wherein the hydrogen producing fuel comprises a chemical hydride.

10. The power generator of claim 1 wherein the hydrogen producting fuel comprises an intermetallic compound selected from the group consisting of Li3Al2, CaAl19, and Mg2Al3.

11. The power generator of claim 1 and further comprising a water vapor hydrogen permeable membrane between the hydrogen producing fuel and the fuel cell.

12. The power generator of claim 1 wherein the fuel cell comprises a PEM membrane with an anode and a cathode.

13. A power generator comprising:

a hydrogen producing fuel;

a metal hydride hydrogen storage element; and

a fuel cell having and cathode, proton exchange member, and anode positioned between ambient the fuel and hydrogen storage element.

14. The power generator of claim 13 and further comprising a pressure regulated valve disposed between the hydrogen producing fuel and the fuel cell, wherein the pressure regulated valve is coupled to a pressure responsive flexible diaphragm.

15. The power generator of claim 14 wherein the pressure regulated valve is coupled to a seat in a closed position when pressure between an anode side of the fuel cell and ambient is above a predetermined level.

16. The power generator of claim 15 wherein the pressure regulated valve is in an open position and allows exposure of the hydrogen producing fuel to the fuel cell when a difference in pressure between the anode side of the fuel cell and ambient is below a predetermined level.

17. The power generator of claim 16 wherein hydrogen produced by the hydrogen producing fuel is stored in the storage element when the pressure in the power generator is above a predetermined value.

18. The power generator of claim 16 wherein hydrogen is released from the storage element when the pressure in the power generator is below a predetermined value.

19. The power generator of claim 18 wherein the hydrogen storage element operates to maintain a temperature dependent constant pressure by adsorbing/desorbing hydrogen as a function of temperature and pressure.

20. A method of providing electricity from a fuel cell based power generator, the method comprising:

producing hydrogen as a function of water vapor and a hydride fuel;

providing hydrogen from a hydrogen storage element; and

producing electricity from hydrogen provided by the hydrogen storage element in response to electricity demands that exceed the ability to produce electricity from hydrogen produced in real time from the hydride fuel.

21. The method of claim 20 and further comprising regulating the flow of hydrogen to the fuel cell as a function of electricity demand.

22. The method of claim 20 wherein hydrogen is stored in the hydrogen storage element when demand decreases.

23. The method of claim 20 wherein the hydrogen storage element comprises a metal hydride hydrogen storage element and the hydrogen storage element comprises a metal hydride including at least one of an ab5 compound, ab2 compound, ab compound, complex alloys, intermetallic compounds or solid solution alloys.

24. The method of claim 23 wherein the storage element has an equilibrium pressure in the range of approximately 0.01 to 10 atmospheres.

25. The method of claim 24 wherein the equilibrium pressure in the range of approximately 0.01 to 10 atmospheres is over an approximately −

20 to 60°

C. temperature range.