KINETICS OF THE PROCESS OF ISOTHERMAL HYDRIDING AND DEHYDRIDING OF HYDROGEN ABSORBERS

A kinetic analysis was done of the process of isothermal absorption an d desorption (hydriding and dehydriding) of some metallic and non-meta llic palladized or platinized hydrogen absorbers. Rate constants for b oth processes were determined for defined temperatures. It was shown t hat these processes proceed as exponential isotherms, following the re lation W-t=W(0)exp (-kt), where k is the rate constant of the process, W is the heat output in a DSC experiment, and t being the time passed . In all cases, the processes follow first order kinetics. Slopes of t he linearized curves yield the wanted rate constants. From the enthalp ies of dehydriding the hydrogen-to-absorber mole ratios were determine d. (C) 1997 International Association for Hydrogen Energy.