Controlled generation of cool hydrogen from solid mixtures

• US 3,977,990 A
• Filed: 10/30/1974
• Issued: 08/31/1976
• Est. Priority Date: 10/30/1974
• Status: Expired due to Term

• Current Assignee: the united states of america as represented by the secretary of the navy
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Barber, William H., Beckert, Werner F., Dengel, Ottmar H., Robb, Robert A.
• Primary Examiner(s): Padgett, Benjamin R.
• Assistant Examiner(s): Leland, David
• Application Number:
  US05/519,312
• Time in Patent Office: 671 Days
• Field of Search: 252/188, 252/188.3, 423/646-648
• US Class Current: 516/11
• CPC Class Codes: C01B 3/04 by decomposition of inorganic compounds, e.g. ammonia C01B3/0005 takes precedence
• CPC Class Codes: Y02E 60/36 Hydrogen production from non-carbon containing sources, e.g. by water electrolysis

Abstract

The hydrogen gas evolution rates and the gas temperatures of certain hydrn gas generating compositions are modified by adding compounds such as LiAlH₄ which thermally decompose in the reaction zone producing hydrogen while lowering the reaction temperature; and acetonates, metal oxides, and the like which, when added in relatively small amounts accelerate the hydrogen gas evolution rate.

Claims

1. In a hydrogen gas generating composition comprising (1) a hydride having the formula Y(ZH₄)_m wherein Y is a mono- or divalent metal capable of forming complex hydrides and is selected from the group consisting of alkali metals and alkaline earth metals, m is the valency of said mono- or divalent metal and Z is a trivalent metal capable of forming complex hydrides and is selected from the group consisting of boron and aluminum, or mixtures of said hydrides;

and (2) a hydrogen producing reactant having the formula (NH₄)_n X wherein X is an inorganic acid group and n is the valency of said inorganic acid group, and mixtures of said compounds, wherein components (1) and (2) are present in stoichiometric amounts in the hydrogen gas generating composition, the improvement comprising the incorporation in said composition of at least one metal hydride coolant which decomposes endothermically to produce hydrogen gas; and

a reaction rate modifier selected from the group consisting of the acetylacetonates of barium, calcium, chromium, cobalt (II), copper (II), iron (II), iron (III), manganese (III), nickel, vanadium, and zinc;

molybdenyl (VI) acetylacetonate;

uranyl acetylacetonate;

vanadyl acetylacetonate;

ferric oxide;

platinum dioxide;

silicon dioxide;

silver oxide;

palladium metal powder;

silver carbonate;

lanthanum chloranilate;

nickel benzoylacetonate;

cuprous oxide;

palladium chloride; and

mixtures thereof.

2. The composition of claim 1 wherein the reaction rate modifier is selected from the group consisting of the acetylacetonates of chromium, cobalt (II), copper (II), iron (II), iron (III), manganese (III), nickel, vanadium and zinc;

molybdenyl (VI) acetylacetonate, uranyl acetylacetonate;

vanadyl acetylacetonate;

ferric oxide;

platinum dioxide;

silicon dioxide;

silver oxide;

palladium metal powder; and

silver carbonate.

3. The composition of claim 1 wherein the reaction rate modifier comprises up to about 10% by weight of said composition.

4. The composition of claim 3 wherein said hydride is NaAlH₄, said hydrogen producing reactant is NH₄ Cl, said coolant is LiAlH₄ and said rate modifier is ferric oxide.

5. The composition of claim 4 wherein said rate modifier comprises about 5% by weight of said composition.

6. The composition of claim 1 wherein the reaction rate modifier is selected from the group consisting of the acetylacetonates of barium and calcium;

lanthanum chloranilate;

nickel benzoylacetonate;

cuprous oxide; and

palladium chloride.

13. The composition of claim 1 wherein said coolant is selected from the group consisting of LiAlH₄, LiBH₄, MgH₂ and AlH₃.

14. The composition of claim 1 further comprising a binder up to about 15% by weight of said composition thereby forming a solid gas generating composition.

15. The composition of claim 14 additionally comprising a suitable plasticizer up to about 30% by weight of said binder thereby improving the mechanical properties of said solid gas generating composition.

16. The composition of claim 14 wherein said binder comprises an isobutyl/styrene copolymer.

7. In a hydrogen gas generating composition comprising (1) a hydride having the formula Y(ZH₄)_m wherein Y is a mono- or divalent metal capable of forming complex hydrides and is selected from the group consisting of alkali metals and alkaline earth metals, m is the valency of said mono- or divalent metal and Z is a trivalent metal capable of forming complex hydrides and is selected from the group consisting of boron and aluminum, or mixtures of said hydrides;

and (2) a hydrogen producing reactant having the formula (NH₄)_n X wherein X is an inorganic acid group and n is the valency of said inorganic acid group, and mixtures of said compounds, wherein components (1) and (2) are present in stoichiometric amounts in the hydrogen gas generating composition, the improvement comprising the incorporation in said composition of at least one metal hydride coolant which decomposes endothermically to produce hydrogen gas; and

a reaction rate modifier selected from the group consisting of the acetylacetonates of thorium and zirconium;

titanyl acetylacetonate;

ferrocene;

thorium oxide;

titanium dioxide reduced iron powder;

uranium tetrachloride; and

mixtures thereof.

8. The composition of claim 7 wherein said coolant is selected from the group consisting of LiAlH₄, LiBH₄, MgH₂ and AlH₃.

9. The composition of claim 7 wherein the reaction rate modifier comprises up to about 10% by weight of said composition.

10. The composition of claim 8 wherein said hydride is NaAlH₄, said hydrogen producing reactant is NH₄ Cl, said coolant is LiAlH₄ and said rate modifier is thorium acetylacetonate.

11. The composition of claim 9 wherein said modifier comprises about 5% by weight of said composition.

12. The composition of claim 7 wherein the reaction rate modifier is selected from the group consisting of zirconium acetylacetonate, titanyl acetylacetonate, ferrocene, thorium oxide, titanium dioxide, reduced iron powder and uranium tetrachloride.

17. The composition of claim 7 further comprising a binder up to about 15% by weight of said composition thereby forming a solid gas generating composition.

18. The composition of claim 17 additionally comprising a suitable plasticizer up to about 30% by weight of said binder thereby improving the mechanical properties of said solid gas generating composition.

19. The composition of claim 17 wherein said binder comprises an isobutyl/styrene copolymer.