Simple scalable approach to advanced membrane module design and hydrogen separation performance using twelve replaceable palladium-coated Al2O3 hollow fibre membranes

Abstract

A phase-inversion approach was used to manufacture Al2O3 hollow fibre supports, which were then sintered at 1723 K. The electroless plating technique is developed to prepare palladium-coated Al2O3 hollow fibre membranes for hydrogen separation. Three different scaling-up configurations were produced and tested: single membrane, membrane unit obtained by assembling three membranes, and advanced membrane module obtained by assembling twelve replaceable membranes. The hydrogen flux was investigated under vacuum and without vacuum using a feed gas of pure H2 (100%) and a binary feed gas mixture of H2 (80%) and CO2 (20%) at different feed gas pressures (100–800 kPa), feed gas rate (0.2–6.0 L min−1), and temperature (673–723 K). The hydrogen flux increases from 0.2162 mol m−2 s−1 (feed gas pressure = 600 kPa, feed gas rate = 0.2 L min−1) to 0.4487 mol m−2 s−1 (feed gas pressure = 800 kPa, feed gas rate = 6.0 L min−1) under the binary gas mixture at 723 K by switching from a single to the advanced membrane module, while the hydrogen purity remains above 97.5% throughout the experiment. Some aspects about the scalability of palladium-coated Al2O3 hollow fibre membranes for hydrogen separation are discussed.