Oxygen permeation study of perovskite hollow fiber membranes

The first oxygen permeation data of a dense hollow fiber perovskite membrane based on BaCoxFeyZrzO3 (-) (delta) are reported. The hollow fiber was prepared by a phase inversion process. Dense fibers were obtained with the following typical geometries: outer diameter, 800-900 mu m; inner diameter, 500-600 mu m; length, 30 cm. The O-2-permeation through the hollow fiber perovskite membrane was, studied in a high-temperature gas permeation cell under different operation conditions. The increase of the helium gas flow rate reduces the oxygen partial pressure (p(O2)) on the core side and a higher oxygen permeation flux is observed. High oxygen flux of 0.73 m(3) (O-2)/(m(2) (membrane) h) was achieved at 850 degrees C under the operation parameters F-air (shell side) = 150 ml/min and F-He (core side) = 30 ml/min. The oxygen partial pressure dependence of the O-2 permeation flux indicated an interplay of both surface reaction and bulk diffusion as rate limiting steps. During 5 days of permeation a high and stable oxygen flux was observed. X-ray diffraction patterns of fresh and spent membranes after the permeation measurements revealed that no degradation after oxygen permeation appears. (c) 2005 Elsevier B.V. All rights reserved.