Demand responsive hydrogen generator based on hydride water reaction

• US 5,514,353 A
• Filed: 06/28/1994
• Issued: 05/07/1996
• Est. Priority Date: 06/28/1994
• Status: Expired due to Fees

• Current Assignee: AF Sammer Corporation
• Original Assignee: AF Sammer Corporation
• Inventors: Adlhart, Otto
• Primary Examiner(s): Warden, Robert J.
• Assistant Examiner(s): Carpenter, Robert
• Application Number:
  US08/266,646
• Time in Patent Office: 679 Days
• Field of Search: 422/211, 422/219, 422/239, 48/61, 48/204, 123/3, 123/DIG. 12, 423/646, 423/647, 423/657, 423/658.2, 429/19
• US Class Current: 422/239
• CPC Class Codes: B01J 7/02 by wet methods
• CPC Class Codes: C01B 3/065 from a hydride
• CPC Class Codes: H01M 2300/0082 Organic polymers
• CPC Class Codes: H01M 8/065 by dissolution of metals or alloys; by dehydriding metallic substances
• 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

Abstract

The reaction of alkali, alkali-earth metal hydride with water is utilized for the generation of hydrogen in a novel generator configuration. This overcomes the problem associated with the expansion of the hydride upon its conversion to hydroxide or oxide when reacting with water encountered in prior art generators. The hydride cartridge is comprised of a structure of corrugated perforated sheet metal and several layers of water wicking material, which hydride granules has dispersed within it. The hydride cartridge is housed in a reactor to which liquid water is admitted in a controlled mode. As the water enters the reactor and reaches the cartridge, hydrogen is instantaneously generated by the hydride water reaction. The hydrogen generation continues as long as unreacted hydride remains and water is being admitted. The wicking material allows the reaction to proceed inasmuch as it overcomes the rate limiting effect of diffusion barriers which may develop as portions of the hydride granules are reacted. As the reaction proceeds, compression of the sheet metal corrugations of the cartridge structure accommodates the volumetric expansion associated with hydride expansion. The combination of the corrugated cartridge structure and the wicking material dispersed throughout the cartridge facilitate the complete utilization of the hydride and water in a demand responsive mode. The generator is utilizable where intermediate hydrogen storage is impractical, e.g., for electric power generation in fuel cells generally and for underwater vehicles to overcome space restraints.

Claims

1. A load responsive hydrogen generator for releasing hydrogen gas from a particle hydride bed as demand for hydrogen warrants, said hydrogen generator comprising:

a) an enclosed housing adapted for containing hydrogen gas under pressure;

b) a hydride storage compartment disposed within said housing for storing a mass of hydride particles dispersed within said compartment;

c) a liquid water storage structure removed from said hydride storage compartment, said liquid water storage structure including a macroporous water absorbent material for storing liquid water;

d) a liquid water transfer means disposed between said liquid water storage structure and said hydride storage compartment for permitting passage of said liquid water from said liquid water storage structure to said hydride storage compartment, said liquid water transfer means being impervious to passage of hydrogen gas from said hydride storage compartment to said liquid water storage structure while permitting passage of liquid water from said liquid water storage structure to said hydride storage compartment;

e) a distribution means for receiving said liquid water from said liquid water transfer means and for distributing said liquid water directly to said hydride particles, thereby permitting conversion of said hydride to hydroxide and generating hydrogen gas in said hydride storage compartment; and

f) a hydrogen release means for releasing said hydrogen gas from said hydride storage compartment upon load demand.

2. The load responsive hydrogen generator according to claim 1 wherein said liquid water transfer means further comprises a hydrophilic microporous member disposed between said liquid water storage structure and said distribution means.

3. The load responsive hydrogen generator according to claim 2 wherein said hydrophilic, microporous member is an inorganic fiber.

4. The load responsive hydrogen generator according to claim 2 wherein said hydrophilic hydroporous member is an organic fiber.

5. The load responsive hydrogen generator according to claim 1 wherein said hydride storage compartment and said liquid water storage structure comprise plastic.

6. The load responsive hydrogen generator according to claim 1 wherein said hydride storage compartment is a disposable cartridge.

7. The load responsive hydrogen generator according to claim 6 wherein said liquid water storage structure comprises a disposable water cartridge made of cellulosic fiber and the quantity of water contained therein before hydrogen generation commences is in excess of that required for the complete conversion of the hydride held in the hydride cartridge.

8. The load responsive hydrogen generator according to claim 1 wherein said distribution means further comprises a liquid water wicking member.

9. The load responsive hydrogen generator according to claim 1 wherein said hydride particles further comprise a compound selected from the group of alkali and alkali-earth metal hydrides.

10. The load responsive hydrogen generator according to claim 1 wherein said hydride particles further comprise calcium hydride.

11. The load responsive hydrogen generator according to claim 1 wherein said hydride particles further comprise lithium hydride.

12. The load responsive hydrogen generator according to claim 1 wherein said hydride particles further comprise lithium-aluminum hydride.

13. The load responsive hydrogen generator according to claim 1 wherein said hydride particles further comprise lithiumborohydride.

14. The load responsive hydrogen generator according to claim 1 wherein said hydride particles are embedded within a wicking material.