Synthesis and oxygen permeation properties of La0.2Sr0.8Co0.2Fe0.8O3-deltamembranes

Three synthesis methods were compared for the preparation of La-0.2 Sr0.8Co 0.2Fe0.8O3-delta (LSCF) powders. It was found that the solid state reaction method is the most easily controlled and effective. A mathematical model i n consideration of membrane bulk diffusion and surface reaction has been de veloped to simulate the performance of the disk-shaped dense membranes for oxygen permeation. The experimental results showed that oxygen permeation f lux of the LSCF membrane increases with the decreasing downstream oxygen pa rtial pressure, and the oxygen permeation flux through a 2 mm LSCF membrane is about 0.32 cm(3)/cm(2) min (STP) at 1123 K and the oxygen partial press ure of 0.21/1x10(-3) atm. The characteristic thickness (L-c) of the LSCF me mbrane was estimated to be 1.8 mm by modeling and experimental study. (C) 1 999 Elsevier Science B.V. All rights reserved.