Metal Hydride Storage for Mobile and Stationary Applications

Metal hydrides offer the possibility of a convenient and safe method for the storage of hydrogen. These compounds provide for compact storage in a form that is equal to or better than cryogenic liquid hydrogen on a volume basis. Considerable research has gone into the study of hydrides derived from rare earth, iton-titanium, and magnesium alloys. The formation of these compounds is reversible and the chemistry of relevant hydrides has been discussed. Heat must be provided to decompose these compounds and release the hydrogen, while heat is liberated when the compounds are formed and must be removed to allow the hydriding reactions to proceed to completion.

The iron-titanium and magnesium alloys are especially promising hydride storage media, the former in stationary applications, or where weight is not a limiting consideration, and the latter for mobile applications. Each of these materials has unique pressure-temperature characteristics and reaction kinetics which must be considered in the design of a hydrogen storage system. These special characteristics are discussed for particular applications. The results of recent work on hydrogen storage development and the engineering design of storage systems are reviewed.