Rolled thin Pd and Pd-Ag membranes for hydrogen separation and production

Thin palladium and palladium alloy membrane tubes with thickness up to 50 mu m have been produced. These metal membranes, used as tube permeators in catalytic membrane reactors for the water gas shift reaction, are thinner than the commercial ones (100-150 mu m) and have both complete selectivity to hydrogen and good durability. A manufacturing procedure consisting of several steps of cold-rolling and annealing the metal foils coupled with a simple welding technique of the tubes has been carried out in order to produce the prototype thin palladium permeators. The procedure of rolling and annealing the palladium and palladium alloy foils is described in detail: the work hardening upon rolling of the palladium and palladium alloy foils has been controlled by means of hardness measurements. Model studies and tests on the membranes and the CMRs for the water gas shift reaction have demonstrated the possibility to separate and recover highly pure hydrogen in energy applications such as nuclear fusion fuel cycle and fuel cells fuelling. (C) 2000 International Association for Hydrogen Energy. Published by Elsevier Science Ltd. All rights reserved.