Purification of Hydrogen Gas Streams

摘要

This report contains the results of a six month feasibility study aimed at the development of high flux palladium-silver membranes for purification of hydrogen gas streams. Membranes were prepared by coating palladium-silver layers onto a variety of support materials using a vacuum sputtering technique. The palladium-silver layers formed were generally less than 0.1 micron thick. Very finely porous or nonporous support materials were required to obtain high quality membranes. The best membranes are extremely selective, with a hydrogen/nitrogen selectivity in the range 150 to 600. These selectivities, combined with hydrogen fluxes ranging from .0005 to .0001-cm3(STP)/sq. cm2/sec/cmHg make the performance of these membranes far superior to any existing membranes. Consistent reproducibility of the membranes remained a problem to some extent throughout the program. However, it is anticipated that this could be overcome by refining the equipment and techniques used in preparation. Screening of more support materials and development of a better support structure would also be valuable in this respect. Taking these steps should enable high flux, high selectivity membranes to be produced consistently.