High flux and CO2 stable La0.6Ca0.4Co0.2Fe0.8O3-δ hollow fiber membranes through internal coagulation bath optimization

Abstract

La0.6Ca0.4Co0.2Fe0.8O3-δ (LCCF) ceramic powder prepared by sol-gel method was used to fabricate LCCF hollow fiber (HF) membranes via a combined phase inversion-sintering technique. Three types of LCCF HF membranes were developed by changing the composition of the internal coagulation bath containing H2O, EtOH or the mixture of NMP + EtOH. The best one was achieved via the mixture (0.7NMP + 0.3EtOH by weight). At 1000 °C, the oxygen flux reached 6.16 mL min-1 cm-2 under inert sweep gas; however, it reached 8.83 mL min-1 cm-2 when reactive CH4 was used as the sweep gas, mirroring the high capability of oxygen transport through the membrane. The good stability of the developed LCCF membrane was confirmed by a series of long-term operation tests up to 300 hours with sweep gas containing CO2. The findings of this work can advance the applications of LCCF membranes to reactors where CO2 atmosphere cannot be avoided.