A tailor-made porous stainless steel support for a dense hydrogen separation membrane

摘要

A tailor-made DPSS (disc-shaped porous stainless steel substrate) for a thin and dense hydrogen membrane with high performance was fabricated by molding pre-treated metal powder, sintering an ingot and then slicing by electrical discharge machining. The sliced DPSS has a diameter of 50.8 mm and a thickness of 1.6 mm. In comparison with commercially produced support (DPSS-M), the sliced DPSS, having surface roughness of 2.7, maximum surface pore size of about 2 mu m, porosity of 33.1% and average pore diameter of 0.58 mu m, is more suitable as the support for the thinner Pd membrane. The hydrogen membrane with Pd layer of 4.4 mu m was prepared and its performance was evaluated. It was shown that the Pd/DPSS membrane had a higher H-2/N-2 selectivity (3825) with a hydrogen flux of 24.7 ml/min/cm(2), than that of Pd/DPSS-M (1821), at del-P =1 and 400 degrees C, even though the surface morphologies of DPSS had been modified with less steps than DPSS-M. For CO2/H-2 separation, the Pd/DPSS membrane enriched 40% CO2 to 90.8% and separated 60% H-2 to 99.8% at 400 degrees C and del-P = 20 bar. Copyright (c) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.