Synthesis of Calcium Hydride from Calcium Carbide in H₂ Gas Stream

Abstract

The hydrogenation of calcium carbide to CaH₂ in H₂ gas flow has been investigated with a pressurized container. The hydrogenation rate was estimated by the analysis of exhausted gas and the chemical analysis of products.
Calcium carbide was converted to CaH₂ perfectly even at a relatively low H₂ pressure (1.1 MPa) though the reaction rate was not efficiently high. The reaction rate depended upon the surface area of a sample, H₂ pressure and temperature. Calcium hydroxide on the surface of the sample, which was formed by the reaction with CaC₂ and H₂O in air, caused the carbon deposition during heating, but it was removed at the early stage of hydrogenation under a pressurized condition.