REACTION-KINETICS OF LANI4.79AL0.21-HYDRIDE

The temperature rise during a hydrogen absorption experiment can be minimized by conducting the experiment over a sufficiently small range in hydrogen content, but it still influences the course of the reaction and therefore cannot be neglected. Kinetic experiments were performed on the LaNi//4//. //7//9Al//0//. //2//1-H system under constant volume and variable pressure conditions. The experiments were analyzed with a non-isothermal model using a lumped mass-transfer coefficient for describing the hydrogen sorption kinetics. The reaction passes through two stages: a fast initial stage where it proceeds to about 90% of completion and a slow terminal stage. This behavior can be represented by the model.