Sodium Alanate Hydrogen Storage Material
AssigneeGM Global Technology Operations LLC
InventorsTerry Johnson, Daniel Dedrick, Robert Stephens, Jennifer Chan
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Abstract
A hydrogen storage material based on sodium alanate contains aluminum in excess of the stoichiometric aluminum content of sodium aluminum tetrahydride. A particulate mixture of sodium alanates, aluminum, and a suitable metal-containing catalyst readily yields, upon heating of the mixture, its hydrogen content for delivery to a hydrogen-using device. The excess aluminum facilitates the sorption of hydrogen, minimizes the amount of necessary catalyst, and improves packing of the particulate mixture and heat transfer to and from the mixture.
Claims10
A method of operating a hydrogen storage system for delivery of hydrogen to a hydrogen-using device, the method comprising:
- adding a predetermined quantity of a hydrogen-containing particulate mixture to a hydrogen storage vessel, the particulate mixture comprising sodium aluminum tetrahydride, aluminum, and a metal-containing catalyst;
- heating the particulate mixture in the storage vessel, upon a demand for hydrogen for the hydrogen-using device, to a hydrogen-release temperature to release hydrogen for delivery to the hydrogen-using device and to successively form Na3AlH6 and then NaH and Al;
- and, when the hydrogen content of the particulate mixture reaches a hydrogen-depleted level,
- adding hydrogen under pressure to the hydrogen-depleted particulate mixture in the vessel while cooling the particulate mixture to facilitate reaction of hydrogen with NaH, Al, and Na3AlH6 to re-form NaAlH4 in the particulate mixture to a hydrogen-restored level for the particulate mixture;
- the aluminum content of the added particulate mixture being predetermined for a prescribed reaction time to reach the hydrogen-restored level with a desired catalyst content.
A hydrogen storage material for providing hydrogen to a hydrogen-consuming device from a vessel of predetermined capacity, the storage material being composed for cycling between a hydrogen-containing condition and a hydrogen-depleted condition, the storage material initially comprising a particulate mixture of sodium aluminum tetrahydride, aluminum, and a metal-containing catalyst, and where the aluminum content is predetermined for a prescribed hydrogenation reaction time in the vessel to reach a hydrogen-restored level with a desired catalyst composition and content.
Dependencies are inferred from the claim text.