Preparation and oxygen permeability of Ce0.8Sm0.2O2 − δ-La0.7Ca0.3CrO3 − δ dual-phase composite hollow fiber membrane

Abstract

Ce0.8Sm0.2O2−δ (SDC)-La0.7Ca0.3CrO3−δ (LCC) dual-phase composite hollow fibers were explored for oxygen separation membrane applications. Hollow fiber precursors were prepared by the phase-inversion/extrusion method using individual metal oxides and carbonates as starting materials, and were converted to gas-tight ceramic by sintering at 1560°C in N2 for 10h. XRD analysis revealed that the sintered hollow fiber comprised of cubic SDC and perovskite LCC phase. SEM observation showed a homogeneous distribution of SDC and LCC grains in the fiber. An oxygen permeation of 2.3×10−7mol⋅cm−2⋅s−1 was observed with a 26.7mm-long hollow fiber by exposing its shell side to atmospheric air and feeding He at 30ml/min into its lumen side at 950°C. A much higher oxygen permeation flux of 3.9×10−6mol⋅cm−2⋅s−1 was observed when the sweep gas was changed from helium to 95%CO+5%CO2. The membrane remained intact after the oxygen permeation test at elevated temperatures under air/CO gradient. Since the hollow fiber membrane exhibited high oxygen permeation flux and satisfactory stability, it holds promise for membrane reactor applications.