Improvements in Synthesis of Palladium Alloy Membranes for Purification of Hydrogen from Water Gas Shift Reaction Mixtures

摘要

Composite membranes, consisting of a thin palladium alloy film supported on a robust, commercially ready, porous substrate, have been investigated as a means of reducing membrane cost and improving the purification of hydrogen from simulated water-gas-shift (WGS) reaction mixtures. With alloy membrane thickness of ≤10 microns the metal cost is not preventive for commercialization, but the presence of pinholes and synthetically introduced defects in the metal membrane can lower the permeate hydrogen purity. We recently demonstrated a simple repair technique to decrease the number of defects and increase the hydrogen-nitrogen pure gas selectivity up to six-fold, without adding any significant Pd thickness to the membranes. In this presentation we will report on the performance of repaired membranes in WGS reaction mixtures over time and an improved synthesis to increase the useful lifetime of these palladium alloy membranes.