Portable chemical hydrogen hydride system

• US 6,544,400 B2
• Filed: 03/30/2001
• Issued: 04/08/2003
• Est. Priority Date: 03/30/2000
• Status: Active Grant

• Current Assignee: Manhattan Scientifics Inc.
• Original Assignee: Manhattan Scientifics Inc.
• Inventors: Hockaday, Robert G., Turner, Patrick S., DeJohn, Marc D., Navas, Carlos J., Vaz, Heathcliff L., Vazul, L. Luke
• Primary Examiner(s): Bell, Bruce F.
• Application Number:
  US09/821,052
• Publication Number:
  US 20010045364A1
• Time in Patent Office: 739 Days
• Field of Search: 204/252, 204/263, 204/264, 204/265, 204/266, 204/276, 422/129, 422/212, 422/255, 422/305, 429/41, 429/46, 429/59, 429/40, 205/637, 205/638, 205/639, 205/343, 205/351, 205/353, 205/338
• US Class Current: 205/338
• CPC Class Codes: B01D 19/0031 by filtration
• CPC Class Codes: B01J 7/02 by wet methods
• CPC Class Codes: C01B 2203/041 In-situ membrane purification during hydrogen production
• CPC Class Codes: C01B 2203/0495 the impurity being water
• CPC Class Codes: C01B 3/0005 Reversible uptake of hydrogen by an appropriate medium, i.e. based on physical or chemical sorption phenomena or on reversible chemical reactions, e.g. for hydrogen storage purposes purification of hydrogen C01B3/508; Reversible gettering of hydrogen; Reversible uptake of hydrogen by electrodes
• CPC Class Codes: C01B 3/065 from a hydride
• CPC Class Codes: C01B 3/501 by diffusion
• CPC Class Codes: H01M 8/04201 Reactant storage and supply, e.g. means for feeding, pipes
• CPC Class Codes: H01M 8/065 by dissolution of metals or alloys; by dehydriding metallic substances
• CPC Class Codes: Y02E 60/32 Hydrogen storage
• CPC Class Codes: Y02E 60/36 Hydrogen production from non-carbon containing sources, e.g. by water electrolysis
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y02P 20/129 Energy recovery, e.g. by cogeneration, H2recovery or pressure recovery turbines

Abstract

A hydrogen source system delivers a controlled fuel stream to applications, using wicking to control the contact between a mixture of NaBH₄, NaOH and H₂O and a hydrolyzing catalyst to create a feedback mechanism to automatically maintain a constant pressure production supply of hydrogen. A small compact device packaged for storage, the system operates in any orientation and is mobile. The system is a small portable packaged hydrogen generator for small fuel cells to power applications that are currently powered by batteries. These packaged devices have higher energy per unit mass, higher energy per unit volume, are more convenient for energy users, environmentally less harmful, and less expensive than conventional power sources.

Claims

1. A hydrogen generator comprising a fuel tank, a wicking material in the fuel tank, a fluid in the wicking material, a hydrophilic membrane bounding the wicking material for receiving the fluid from the wicking material by a wicking pressure, a surface proximal to the hydrophilic membrane, a catalyst on the surface, and hydrogen generated by hydrolyzation of the fluid contacting the catalyst due to reduced internal pressure.

2. The apparatus of claim 1, further comprising a first pressure regulation for controlling wicking of the fuel from the wicking material.

3. The apparatus of claim 2, further comprising a second pressure regulation providing capillary pressure and a third pressure regulation providing a generated hydrogen pressure for regulating generation of the hydrogen.

4. The apparatus of claim 1, further comprising a matrix and a reservoir for the fluid in the tank, and a capillary pressure gradient created by the matrix for circulating a bubbling fluid from the reservoir in the tank.

5. The apparatus of claim 4, wherein the matrix comprises a porous material having a pore diameter gradient for creating the capillary pressure gradient.

6. The apparatus of claim 1, further comprising tapered pores or channels in the tank and a capillary pressure gradient created by the tapered pores or channels.

7. The apparatus of claim 6, wherein the capillary pressure gradient created by the pores changes surface tension energy with geometric positioning of the fluid.

8. The apparatus of claim 1, further comprising capillary pressure in the tank for separating the hydrogen from the fluid.

9. The apparatus of claim 1, wherein the fluid comprises a chemical hydride in solution producing the hydrogen on contacting the catalyst.

10. The apparatus of claim 1, wherein the fluid comprises a solution of NaBH₄+NaOH+H₂O and wherein the catalyst is Ru.

11. The apparatus of claim 1, wherein the fluid comprises a hydrocarbon and wherein the catalyst is a solid catalyst.

12. The apparatus of claim 1, wherein the fluid comprises a hydrocarbon and the catalyst is Pt and Ru.

13. The apparatus of claim 1, further comprising separate compartments for storing the fluid and the catalyst in a non-generating state and for mixing from the compartments when the hydrogen production is desired.

14. The apparatus of claim 13, further comprising a separation barrier between the compartments for breaching and contacting the fluid with the catalyst and for generating the hydrogen.

15. The apparatus of claim 1, wherein the catalyst comprises two electrodes for electrochemically acting on the fluid to produce the hydrogen.

16. The apparatus of claim 1, further comprising a thermoregulation device for heating the catalyst for increasing hydrogen production.

17. The apparatus of claim 16, wherein the thermoregulation is by an electrode in the catalyst electrically heated for increasing the hydrogen production.

18. The apparatus of claim 16, wherein the thermoregulation device is selected from a group consisting of a thermopile, diversion of exhaust, evaporative cooling, gas compression refrigerator, heat pump, resistance wire and combinations thereof.

19. The apparatus of claim 1, wherein the surface is an electrical resistance heated catalytic surface for increasing hydrolysis reaction rates, and a feedback mechanism in the tank for controlling electrical heating proportional to a load and for adjusting a production rate proportional to a need for the hydrogen.

20. The apparatus of claim 1, wherein the catalyst is a fuel cell electrode.

21. The apparatus of claim 20, wherein the fuel cell electrode is part of a fuel cell comprising a pore free hydrogen selective membrane.

22. The apparatus of claim 21, wherein the hydrogen selective membrane separates the fluid and the catalyst.

23. The apparatus of claim 20, wherein the fuel electrode is a metal hydride capable of storing hydrogen.

24. The apparatus of claim 20, wherein the fuel cell electrode comprises capillary pressure gradient electrodes for using bubbling of the fluid to circulate the hydrogen through the electrode.

25. The apparatus of claim 24, further comprising pressure of the hydrogen and capillary pressure, wherein the capillary pressure gradient electrodes prevent contact of the fluid with the fuel cell electrode when undesired.

26. The apparatus of claim 1, further comprising a selective gas permeable membrane for separating the hydrogen and the fluid.

27. The apparatus of claim 26, wherein the selective gas permeable membrane is more permeable to molecules of the hydrogen than to molecules of the fluid.

28. The apparatus of claim 27, wherein the selectively permeable membrane is a platinum coated palladium silver alloy film supported on a porous surface.

29. The apparatus of claim 1, further comprising a valve between the fluid and the catalyst.

30. The apparatus of claim 1, further comprising a pump between the fluid and the catalyst.

31. The apparatus of claim 1, where the wicking positions the fluid on the hydrophilic membrane after hydrolysis.

32. The apparatus of claim 1, wherein the wicking material comprises an absorbent material.

33. The apparatus of claim 1, wherein the wicking material comprises a neutralizing material for neutralizing spent fuel in the fluid.

34. The apparatus of claim 33, wherein the wicking material fully utilizes chemical energy in the fuel.

35. A hydrogen generation process comprising providing a fluid and a catalyst in a fuel tank, contacting the fluid and the catalyst, causing dehydrogenation of the fluid on contacting with the catalyst, generating hydrogen, coupling a pressure of the generated hydrogen to a mechanical means, causing bubble formation and capillary wetting for positioning the fluid.

36. The process of claim 35, further comprising regulating further generation of hydrogen using the pressure of the generated hydrogen.

37. The process of claim 35, wherein providing the catalyst comprises providing a fuel cell electrode.

38. The process of claim 35, wherein contacting the fluid and the catalyst comprises expanding and contracting the fuel tank to respectively press in contact or remove from contact the fluid and the catalyst in the tank.