Membranes of Palladium Alloys for Ultrapure Hydrogen Production

Abstract

The high-grade leak-tight foils 10–20 μm in thickness were obtained from effective alloys (wt %) Pd–6 In–0.5 Ru, Pd–6 Ru, and Pd–40 Cu by using advanced technology. For the Pd–40% wt Cu alloy, the foil with ordered β phase with the CsCl structure, exhibiting maximum hydrogen permeability in the Pd–Cu system, was formed by the combination of deformation and annealing conditions. The mechanical properties and hydrogen permeability of the obtained foil membranes as compared with the foils of 50 μm in thickness and also their performance for pure hydrogen at the membranes work in the commercially pure hydrogen medium were investigated. The concentration dilatation of the foils in hydrogen was investigated at various temperatures. Data on dilatation of palladium membrane alloys are of paramount importance to design of membrane filter elements and choice of their optimal usage conditions because these data determine the operational life of membrane. The Pd–6 wt % In–0.5 wt % Ru–1.25 wt % Co alloy with improved strength characteristics and lower temperature of α ↔ β hydride transition was developed on the basis of the Pd– 6 wt % In–0.5 wt % Ru alloy.