Prospects and problems of dense oxygen permeable membranes

The prospects of using mixed ionic/electronic conducting ceramics for synga s production in a catalytic membrane reactor are analysed. Problems relatin g to limited thermodynamic stability and poor dimensional stability of cand idate materials are addressed, The consequences for these problems, of flux improving measures like minimization of membrane thickness and minimizatio n of the losses due to oxygen exchange over the membrane surfaces, are disc ussed. The analysis is conducted on two candidate materials: La0.6Sr0.4Co0. 2Fe0.8O3-delta and SrFeCo0.5Ox. Finally. experimental investigations of the dimensional stability of the latter material under reducing conditions are reported. (C) 2000 Elsevier Science B.V. All rights reserved.