Permeation and Mechanical Properties of Porous Supports Intended for Asymmetric Membranes Based on La(0.2)Sr(0.8)Fe(0.8)Al(0.2)O(3-δ)

Abstract

Production of asymmetric ceramic membranes intended for oxygen gas separation was done by producing porous supports made from coarse La(0.2)Sr(0.8)Fe(0.8)Al(0.2)O(3-d) powder produced by the solid state reaction method. The porous support was made by adding 40 vol% carbon black as a pore former to a slip which was tape casted. The tape casted green body was dip-coated with a solution of nano-sized La(0.2)Sr(0.8)Fe(0.8)Al(0.2)O(3-d) particles produced by spray pyrolysis, and fired. The asymmetric membranes produced during this work was not gas tight, and thus not viable to use for oxygen gas separation. Phase pure La(0.2)Sr(0.8)Fe(0.8)Al(0.2)O(3-d) was not prepared by the solid state reaction method in this work, and possible reasons for this is discussed. The gas permeability of the porous support was measured at room temperature. The gas permeability at elevated temperatures was calculated for different pressure drops across the porous support and the estimated gas permeability at elevated temperatures seems promising (58 mL/min cm2 at 1000C, p = 10mbar). The porosity of the porous support was determined to 62.3% by Archimedes method, this seems plausible when comparing the results with SEM micrographs. Due to time restraints no mechanical testing was done