Ce0.85Sm0.15O2-Sm0.6Sr0.4Al0.3Fe0.7O3 composite for the preparation of dense ceramic-carbonate membranes for CO2 separation

In the last years, it has been proposed the use of ceramic-carbonate dense membranes to separate CO2, selectively from combustion gas, at high temperatures. The mechanism of CO2 separation of these membranes involves the transport of O(2-)ions through the ceramic phase of the membrane. Thus, the present study examines the Ce0.85Sm0.15O2-Sm0.6Sr0.4Al0.3Fe0.7O3 composite to prepare such a ceramic-carbonate membrane, as this composite has been previously reported as an excellent oxygen conductor. Firstly, the composite was prepared by two different synthesis pathways, both based on the EDTA-citrate complexing method. Subsequently, disk shape membrane supports were produced by pressing selected powder samples and they were evaluated in terms of their thermal and chemical stability. Furthermore, ceramic-carbonate membranes were prepared via direct infiltration with molten carbonates and evaluated at high temperatures for the CO2 separation. Results suggest the possible application of this composite for the fabrication of stable dense membranes performing selective CO2 separation at high temperatures (700-900 degrees C).