Oxygen permeability and structural stability of CO2-stable SDC–SSCFG dual-phase membrane

Abstract

Ce0·8Sm0·2O2−δ –Sm0·3Sr0·7Co0·6Fe0·3Ga0·1O3−δ dual-phase membranes with different weight ratios were successfully developed, and the microstructure, structural stability, oxygen (O2) permeability and oxygen permeation stability using helium (He) or carbon dioxide (CO2) as sweeping gas were systematically investigated. It is found that the oxygen fluxes through dual-phase membranes decrease with the increase in Ce0·8Sm0·2O2−δ content. The oxygen permeation flux of 80Ce0·8Sm0·2O2−δ –20Sm0·3Sr0·7Co0·6Fe0·3Ga0·1O3−δ dual-phase membrane reaches 0·48 ml/(min cm2) with pure carbon dioxide as the sweeping gas. By reducing the thickness of the membrane and porous Sm0·7Sr0·3CoO3−δ activation layer coating on the permeate side, a stable flux of 0·62 ml/(min cm2) can be obtained during a long-term oxygen permeation operation for 100 h. The Ce0·8Sm0·2O2−δ –Sm0·3Sr0·7Co0·6Fe0·3Ga0·1O3−δ dual-phase membranes show excellent oxygen permeability and structural stability in carbon dioxide atmosphere and could have great potential application in oxy-fuel techniques for carbon dioxide capture and storage.