ISOTOPE-SEPARATION FACTOR AND ISOTOPIC EXCHANGE-RATE BETWEEN HYDROGENAND DEUTERIUM OF PALLADIUM

An isotopic exchange experiment was performed using a Pd particle bed for a fundamental study of hydrogen isotope separation. The isotope se paration factor and the rate constant of the isotopic exchange reactio n between gaseous deuterium and hydride were determined from fitting n umerical calculations to experimental effluent curves of the Pd bed. T he separation factors under the condition of a dilute deuterium concen tration were correlated with the relation of alpha(H-D) = exp(-0.121 228/T) and were independent of the total hydrogen pressure. The rate- determining step of the overall isotopic exchange reaction at T > 300 K was diffusion in the pore of Pd particles. The step at T < 300 K was estimated to be diffusion in the beta-phase Pd, although there is a l ittle possibility of isotopic exchange reaction based on Bonhoeffer-Fa rcus mechanism. The height equivalent to a theoretical plate, HETP, wa s correlated as a function of the interstitial fluid velocity in the b ed.