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

摘要

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/(smPa~(0.5)) at 673 K and 2.62·10~3 mol/(smPa~(0.5)) 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 H_2O 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.