Simultaneous hydrogen and oxygen permeation through BaCe0.70Fe0.10Sc0.20O3-δ perovskite hollow fiber membranes

Abstract

BaCe0.70Fe0.10Sc0.20O3-δ (BCFS) perovskite hollow fiber membrane was prepared by the phase inversion and sintering technique. With a minor amount of Co2O3 (1.0 wt%) as the sintering aid, a gas-tight membrane was obtained at a lower temperature (1400 °C) compared with the original sintering temperature of 1550 °C. Meanwhile, the mechanical strength was also enhanced with the addition of Co2O3. BCFS membrane shows both hydrogen and oxygen permeability and is able to permeate both gases in a simultaneously manner. This feature inspires great potential applications as a new type of catalytic membrane reactor for various dehydrogenation or hydrogenation reactions where hydrogen or steam management is important. Hence, the simultaneous permeation behaviour of hydrogen and oxygen permeation through the BCFS membrane is investigated. The results show that both hydrogen and oxygen fluxes are remarkably enhanced via the simultaneous permeation mode. At 1000 °C, hydrogen and oxygen fluxes in the simultaneous permeation mode were 135% and 75% higher than those in a single permeation mode. The mechanism of such enhancement by simultaneous permeation was explored. As the reaction between hydrogen and oxygen decreases the H2 and O2 concentration in the permeate side, the driving force for their individual permeation increases. This increment plays a dominant role in permeation enhancement. Additionally, steam formation also enhances surface gas/ion exchange reactions to accelerate hydrogen and oxygen permeation.