Thermodynamic threshold for Pd4S formation in H2S Poisoning of hydrogen purifier palladium membranes

The influence of H2S-to-H2 ratio in real feed stream in sulfidation of pure palladium membranes was investigated through the comparison of the last decade experimental results in which pure palladium membrane experience varying H2S-to-H2 by those predicted by developing Pd4S equilibrium diagram which obviously delimit stable and unstable threshold condition for the Pd4S formation. The most of cases exhibit good agreement between predicted and experimental results. However, some cases have shown inconsistency. That is because of difference in hydrogen partial pressure which cause sulfur to develop strong covalent bond instead of sulfidation

Keywords:

Hydrogen purification , Pure palladium membrane , Pd4S equilibrium phase diagram , palladium poisoning mechanism