Stability of Ta/YSZ cermet membrane for hydrogen separation

Abstract

A dense cermet membrane consisting of tantalum metal and yttria-stabilized zirconia has been developed for separation of hydrogen from hydrogen containing gas mixtures. Ta/YSZ membrane without secondary phase can be obtained by mechanical polishing after high vacuum sintering. As-prepared membrane showed dense structure with continuous channel of tantalum. Hydrogen permeation experiments were conducted using different cell to investigate the optimum sealing method. Hydrogen fluxes through these cermet membranes were measured in the region of 350–500 °C. The permeation flux increased monotonically with increasing the temperature. The highest hydrogen flux was 1.2 ml/min⋅cm 2 for a cermet membrane of 0.5 mm cm thick at 300°C using 100% H 2 as the feed gas and Ar as the sweep gas. Ta/YSZ membrane was deteriorated by tantalum hydride formed during permeation with brazing sealing but in the case of knife edge type sealing, no tantalum hydride was detected on the surface of Ta/YSZ cermet membrane.