A chemically stable La0.2Sr0.8Fe0.9Mo0.1O3-δ-molten carbonate dual-phase membrane for CO2 separation

We report here a mixed oxygen ionic-electronic conductor-molten carbonate composite membrane for high temperature CO 2 separation. Mo-doping at Fe-site of La 0.2 Sr 0.8 FeO 3-δ (LSF) is attempted to address its stability issue in CO 2 or carbonate-containing environment. The La 0.2 Sr 0.8 Fe 0.9 Mo 0.1 O 3-δ (LSFM)-molten carbonate membrane with 1 mm thickness delivers a CO 2 permeation flux of 1.57 × 10 −3 mol m −2 s −1 at 800 °C with 50% CO 2  + 50 % N 2 (total 1 atm) as feeding gas and pure He (1 atm) as sweeping gas, compared to 0.737 × 10 −3 mol m −2 s −1 for the LSF counterpart. The CO 2 permeation flux further increases to 2.25 × 10 −3 mol m −2 s −1 for membrane prepared with Al 2 O 3 coated LSFM substrate. An even higher CO 2 permeability of 2.69 × 10 −3 mol m −2 s −1 is demonstrated for LSFM-molten carbonate membrane at 800 °C when using simulated flue gas (15% CO 2  + 10% O 2  + 75 % N 2 in total 1 atm) as feeding gas. The membrane also exhibits relatively stable CO 2 and O 2 fluxes during 50 h test at 750 °C. The designed LSFM-molten carbonate membrane can be potentially used as a reactor for dry methane reforming and partial oxidation of methane with flue gas as direct feedstock.