PdCu membrane applied to hydrogen production from methane

A PdCu membrane was characterised and then tested in complex hydrogen containing streams from methane oxidation and reforming processes. The hydrogen permeance and stability of the PdCu membrane, prepared by electroless plating, was analysed in pure hydrogen and by thermal cycling in inert and hydrogen atmospheres. This membrane was then placed in a membrane module, into which the product gases from a catalytic reactor were fed. Methane catalytic partial oxidation (CPO) and wet-CPO were performed in the catalytic reactor. Firstly, process feed pressure and sweep gas flow were optimised and, finally, the effect of mixture compounds (CO, CO2, CH4 and H2O) on membrane behaviour was analysed. Changes in the composition of the mixture fed into the membrane module had only little influence on membrane performance during the 30 h of operation. Around 60% of the hydrogen produced in the catalytic reactor was separated in the membrane module, operating at 673 K, 3.5 bar(g) feed pressure and 550 NmL/min of sweep gas. The membrane was characterised using SEM and XRD.