Two step novel hydrogen system using additives to enhance hydrogen release from the hydrolysis of alane and activated aluminum
View Patent ↗A system for the generation of hydrogen for use in portable power systems is set forth utilizing a two-step process that involves the thermal decomposition of AlH 3 (10 wt % H 2 ) followed by the hydrolysis of the activated aluminum (Al*) byproduct to release additional H 2 . Additionally, a process in which water is added directly without prior history to the AlH 3 :PA composite is also disclosed.
1. A process of generating hydrogen comprising the steps of:
providing a source of AlH 3 ;
heating the AlH 3 to a temperature of at least about 150°, thereby forming reaction products consisting of a fast hydrogen gas and activated aluminum; and,
adding a promoter to the activated aluminum reaction product, the promoter being selected from the group consisting of NaAlH 4 , NaH, and NaOH to provide a composite material;
adding a stoichiometric amount of water to the composite material, thereby generating a second hydrogen gas source.
2. The process according to claim 1 wherein the step of adding a stoichiometric amount of water further provides increasing the amount of water to twice the stoichiometric amount.
3. The process according to claim 1 wherein step of heating the AlH 3 uses heat generated from a thermolysis of an AlH 3 containing composite material.
4. The process according to claim 1 wherein said step of adding a promoter to activated aluminum removes an oxide layer present of the surface of the activated aluminum.
5. The process according to claim 1 wherein the activated aluminum has a particle size and shape similar to the AlH 3 material but has a greater surface area following the heating step of AlH 3 .
6. The process according to claim 1 wherein between about 3.3 weight % to about 3.6 weight % of hydrogen is released from the composite and water combination.
7. The process according to claim 1 wherein the composite material releases between about 10.0 weight % to about 10.6 weight % relative to the dry weight of the composite material.
8. The process according to claim 1 wherein said step of heating the AlH3 comprises heating the AlH3 to a temperature of between about 185° C. and about 200° C.
9. A process of providing hydrogen comprising the steps of:
providing a source of AlH 3 ;
adding a promoter to the AlH 3 , the promoter selected from the group consisting of NaAlH 4 , NaH, NaOH and combinations thereof to provide a composite material; and
adding water to the composite material, thereby generating a hydrogen gas reaction product without the addition of external heat.
10. The process according to claim 9 wherein the step of adding the promoter to the AlH 3 removes a polymeric coating on the surface of the AlH 3 .