PdCu membrane integration and lifetime in the production of hydrogen from methane

Abstract

PdCu membranes prepared by sequential electroless plating were integrated into a hydrogen production and purification process. Hydrogen was produced from methane through catalytic partial oxidation and wet catalytic partial oxidation with Ni-based catalysts. Membrane permeance was measured with thermal cycles in an inert and hydrogen atmosphere at 673 and 773 K. Permeability was 1.98·10−3 mol/(smPa0.5) at 673 K and 2.62·10−3 mol/(smPa0.5) at 773 K. The optimum sweep gas flow required in the membrane module when operating with hydrogen-containing mixtures was selected. Peak hydrogen recovery was obtained using 15–20% of the feed to the module as sweep gas flow. Membranes were then placed downstream of the hydrogen production reactor. The CO and H2O percentages fed to the membrane module did not have a major impact on membrane behavior. Around 60–67% of the hydrogen fed to the membrane module was separated, regardless of its composition.