Hydrogen is a “clean fuel” because it can be reacted with oxygen in hydrogen-consuming devices, such as a fuel cell or combustion engine, to produce energy and water. Virtually no other reaction byproducts arc produced in the exhaust. As a result, the use of hydrogen as a fuel effectively solves many environmental problems associated with the use of petroleum based fuels. Safe and efficient storage of hydrogen gas is therefore, essential for many applications that can use hydrogen. In particular, minimizing volume and weight of the hydrogen storage systems are important factors in mobile applications.
Several methods of storing hydrogen currently exist but are either inadequate or impractical for wide-spread consumer applications. For example, hydrogen can be stored in liquid form at very low temperatures. However, liquid hydrogen is neither safe nor practical for most consumer applications. Moreover, the energy consumed in liquefying hydrogen gas is about 60% of the energy available from the resulting hydrogen.
As a result of these and other disadvantages of hydrogen storage and transportation, the art has turned to fuel cells and systems for the generation of hydrogen. Such systems are known. for example Amendola et al, Abstracts ACS National Meeting, August, 1999, pages 864–868. describe such a system that is suitable for use in motor vehicles that is based on the catalyst generation of hydrogen from an aqueous metal hydride solution. In accordance with the present invention, an improvement in the operation of such systems is provided.