Proceedings of the 2000 Hydrogen Program Review NREL/CP-570-28890

Abstract

This paper describes the work performed on two programs supported in part by the U.S. Department of Energy. These programs are aimed at evaluating the potential of using slurries of chemical hydrides and organic liquids to store hydrogen. The projects have been very successful in meeting all project objectives. After a detailed analysis of chemical hydrides, lithium hydride was selected for use in these programs. Lithium hydride has been prepared as a slurry with light mineral oil and a dispersant and has been found to be stable for long periods of time at atmospheric temperatures and pressures. We have demonstrated that the lithium hydride slurry can be mixed with water to produce hydrogen on demand. Reactions between the lithium hydride slurry and water take place rapidly and completely. The resulting lithium hydroxide can be recycled either by electrolytic methods or by a carbo-thermal process. Experiments with the carbo-thermal process indicate that the regeneration of lithium hydride can be accomplished at temperatures of 1500°K or less enabling the use of economically acceptable furnace materials. A cost analysis of the regeneration process indicates that the process should be cost competitive with hydrogen produced from natural gas and stored as a liquid or a highly compressed gas.