High-performance Ba(Zr0.1Ce0.7Y0.2)O3−δ asymmetrical ceramic membrane with external short circuit for hydrogen separation

Abstract

Ba(Zr0.1Ce0.7Y0.2)O3−δ asymmetric ceramic membrane with external short circuit (ESC asymmetrical membrane) was developed for further improving hydrogen separation efficiency. Hydrogen permeation flux(JH2) of ESC asymmetrical membrane is higher than those of traditional Ni–Ba(Zr0.1Ce0.7Y0.2)O3−δ membranes, e.g., 1.71 × 10−7 mol cm−2 s−1 for ESC asymmetrical membrane while 1.37 × 10−8 mol cm−2 s−1 for Ni-BZCY asymmetric membrane at 900 °C [11]. However, the activation energy of hydrogen permeation is higher for ESC asymmetrical membrane. Hydrogen fluxes of ESC asymmetrical membrane increase with the rising of temperature and hydrogen partial pressure gradient across both sides of membrane. The linear relationship between JH2 and ln(p′H2/p″H2) indicates that hydrogen permeation occurs via the ambipolar diffusion of proton and electron in ESC asymmetrical membrane and is controlled by the bulk diffusion of proton. The stability testing in CO2-containing atmosphere indicated that hydrogen permeation output remained unchanged in 3%CO2 feed gas but a pronounced decline of 8% was observed after 50-h operation in 20% CO2 feed gas.