Empirical correlation of equilibrium separation factors in the Pd-H-2/D-2 system with temperature and composition

The range of available data on separation factors (a) in the palladium-hydr ogen/deuterium system has been extended in this study using a thermal condu ctivity detector. The thermal conductivity detector employed a matched pair of glass-coated bead thermistors to measure the gas-phase composition of h ydrogen isotope mixtures. Separation factors (cl) were measured in the P-ph ase, over the temperature (T) and hydrogen mole fraction (x(H)) ranges T = 175 K to 389 K and xH = 0.195 to 0.785, respectively. These data were corre lated with temperature (T) and hydrogen mole fraction in the palladium (xH) by a = exp[-0.27 + B(x(H))(1000/T)(0.75)] and B(x(H)) = 0.5155 - 0.0569x(H ) - 0.12x(H)(2), where B(x(H)) is an empirical function relating the depend ence of the separation factor on composition.