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 CO2 separation. Mo-doping at Fe-site of La0.2Sr0.8FeO3-delta (LSF) is attempted to address its stability issue in CO2 or carbonate-containing environment. The La0.2Sr0.8Fe0.9Mo0.1O3-delta (LSFM)-molten carbonate membrane with 1 mm thickness delivers a CO 2 permeation flux of 1.57 x 10(-3) mol m(-2) s(-1) at 800 degrees C with 50% CO2 + 50 % N-2 (total 1 atm) as feeding gas and pure He (1 atm) as sweeping gas, compared to 0.737 x 10(-3) mol m(-2) s(-1) for the LSF counterpart. The CO2 permeation flux further increases to 2.25 x 10(-3 )mol m(-2) s(-1) for membrane prepared with Al2O3 coated LSFM substrate. An even higher CO2 permeability of 2.69 x 10(-3) mol m(-2) s(-1) is demonstrated for LSFM-molten carbonate membrane at 800 degrees C when using simulated flue gas (15% CO2 + 10% O-2 + 75 % N-2 in total 1 atm) as feeding gas. The membrane also exhibits relatively stable CO2 and O-2 fluxes during 50 h test at 750 degrees 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.

Automated summary

A novel mixed oxygen ionic-electronic conductor-molten carbonate composite membrane was developed for high temperature CO2 separation, addressing stability issues in CO2 environments. The LSFM-molten carbonate membrane exhibited excellent CO2 permeation performance under different conditions, showing potential for various applications.