Development of mixed conducting membranes for clean coal energy delivery

Mixed conducting membranes can be used for the separation of oxygen from air in both coal gasification and oxy-fuel power plants. In this review paper, the basic perovskite and non-perovskite structures, composition, properties and performance are addressed. Two typical perovskite materials, BSCF and LSCF, show promise in industrial applications as their oxygen fluxes are at least one order of magnitude higher than non-perovskite membranes. BSCF membranes are now delivering oxygen fluxes in excess of 5 ml min−1 cm−2. Latest developments in perovskite composition, effects of impurities in membrane performance and membrane geometry are discussed giving an insight into the potential utilisation in clean energy delivery processes. Strategies for improving membranes performance using unit operations with different geometries and possible future technologies are also addressed.