Development of hydrogen storage for fuel cell generators. I: Hydrogen generation using hydrolysis hydrides

The feasibility of a hydrogen storage system for alkaline fuel cells using decomposable hydrides was investigated. These hydrides generate hydrogen according to the following reaction: MHx + xH(2)O --> M(OH)(x) + xH(2) where M is a metal of valence x. A small bench scale reactor was designed and tested using different decomposable hydrides. The hydrolysis reaction rates were high, with the evolution of significant heat. The reactions were found to be more easily controlled with water vapour than with liquid water. Constant reaction rates over a wide range of yields, and overall yields of over 96 and 90%, respectively, were obtained with calcium hydride and lithium hydride. Based on the highest ultimate yields, calcium hydride and lithium hydride were recommended for further investigation. (C) 1999 International Association for Hydrogen Energy. Published by Elsevier Science Ltd. All rights reserved.