The La0.6Sr0.4Co0.2Fe0.8O3 mixed conducting hollow fibre membranes were

prepared via the combined phase inversion and sintering technique. A porous layer

of silver or perovskite was coated on the outside surface of the hollow fibres to

improve the surface exchange kinetics. Oxygen permeation fluxes through both the

modified and the unmodified hollow fibre membranes were measured under air/He

gradients at different temperatures. The oxygen permeation process through the

unmodified hollow fibre membranes was mainly controlled by the oxygen

dissociation on the membrane surface exposed to feed gas of air. After surface

modifications, the oxygen permeation fluxes can be improved from the original

values of 0.01 to 0.81mlSTP/cm2min in the unmodified hollow fibre membrane to

0.08 to 1.85ml/cm2min in the Ag-coated membrane and to 0.05 to 1.48ml/cm2min

in the porous modified membrane, respectively, at 700 to 1000C. The maximum

enhancements for the Ag-coated and the porous modified membranes were found,

at 800C, to be 17.8 and 9.3 times the original flux, respectively. Due to the surface

modifications, the operating temperature to achieve anticipated oxygen permeation

fluxes of commercial interest can be reduced noticeably.

Enhancement of Oxygen Permeation Through La0.6Sr0.4Co0.2Fe0.8O3−δ Hollow Fibre

Membranes by Surface Modifications. X.Tan, Z.Wang, H.Liu, S.Liu: Journal of

Membrane Science, 2008, 324[1-2], 128-35