Miniature hydrogen generator

• US 4,155,712 A
• Filed: 10/06/1977
• Issued: 05/22/1979
• Est. Priority Date: 04/12/1976
• Status: Expired due to Term

• Current Assignee: Walter G. Taschek
• Original Assignee: Walter G. Taschek
• Inventors: Taschek, Walter G.
• Primary Examiner(s): Tayman, Jr., James H.
• Application Number:
  US05/839,949
• Time in Patent Office: 593 Days
• Field of Search: 23/282, 23/281, 423/657, 48/4
• 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 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

A relatively small size apparatus for generating hydrogen by the reaction of a metal hydride with water vapor is disclosed. The metal hydride utilized to generate the hydrogen gas is housed in a fuel chamber of the apparatus and water vapor is introduced into the fuel chamber through a porous membrane having selected characteristics. The metal hydride reacts with the water vapor in a conventional manner to produce pure hydrogen. A variable gas pressure - liquid pressure balance means for introduction of water vapor enables automatic hydrogen generation on demand and enables complete shut down when demand ceases. The apparatus of this invention may be operated at any selected constant pressure feed rate. Further, with the apparatus of this invention the water source is effectively isolated from the metal hydride by the porous membrane, which has hydrophobic characteristics, and as a consequence, both contamination of the water source and caking of the metal hydride fuel is minimized. The apparatus of this invention can be utilized as a hydrogen or other gas source in many applications where a source of hydrogen or other gas is required but is ideally suited for regulated and pressure feed applications, for example, as the hydrogen source for the hydrogen electrode of the fuel cell.

Claims

1. An automatic, demand responsive gas generator for producing gas by chemical reaction of a solid fuel upon controlled exposure to a liquid vapor, said generator comprising:

a compartment for storing solid fuel;

a first compartment adapted to contain a liquid such as water;

a wall common to said fuel compartment and said liquid compartment, said wall including a porous hydrophobic membrane of Teflon material of a selected wall thickness adapted to pass gaseous and vaporous mediums and

to restrict free passage of said liquid;

a second compartment adapted to contain a second portion of said liquid;

a hollow tubular means interconnecting said first and second liquid compartments;

said second liquid compartment being disposed above said first liquid compartment such that the mass of liquid in said second compartment exerts a head pressure on said first liquid compartment; and

a gas outlet connected to said fuel compartment for conducting produced gas to a gas utilization means whereby the gas utilization causes a decrease in gas pressure in the fuel compartment and the first liquid compartment which causes liquid to flow from said second liquid compartment into said first liquid compartment and increases the liquid vapor diffusion into the fuel compartment thereby increasing the gas production rate.

2. An automatic, demand responsive, gas generator as defined in claim 1 wherein said selected wall thickness of said porous membrane is in the general 5 to 19 mils region and the bubble pressure characteristic of the porous membrane material is at least 0.1 psi.