Method for generation of hydrogen gas from borohydride

Abstract

A method for generation of hydrogen by combining a solid composition containing a borohydride compound and a base with an aqueous solution of an acid.

Description

Claims

1. A method for generation of hydrogen comprising: (a) providing a solid composition comprising from 3% to 50% of at least one base; and 50% to 97% of at least one borohydride compound; and(b) adding to the solid composition an aqueous solution of at least one acid; said aqueous solution comprising from 0.01 to 2 equivalents of acid;wherein the solid composition and the aqueous solution are substantially free of transition metals from groups 8, 9 and 10.

2. The method of claim 1 in which said at least one borohydride compound is at least one alkali metal borohydride, and said at least one base is sodium, lithium or potassium hydroxide, sodium or potassium methoxide, or a combination thereof.

3. The method of claim 2 in which in which the solid composition comprises at least 5% of said at least one base and no more than 95% alkali metal borohydride.

4. The method of claim 3 in which said at least one alkali metal borohydride is sodium borohydride, potassium borohydride or a combination thereof

5. The method of claim 4 in which the acid is a C2-C5 dicarboxylic acid, a C2-C5 hydroxy carboxylic acid, a C2-C5 hydroxy dicarboxylic acid or a combination thereof.

6. The method of claim 5 in which the alkali metal borohydride is sodium borohydride and the base is sodium hydroxide.

7. The method of claim 6 in which the acid is selected from among the group consisting of malic acid, citric acid, tartaric acid, malonic acid, oxalic acid and combinations thereof.

8. The method of claim 7 in which the aqueous solution comprises from 0.1 to 1 equivalents of acid.

9. The method of claim 8 in which the solid composition comprises from 5% to 15% of sodium hydroxide and from 85% to 95% sodium borohydride.