Concurrent and modulated separation of CO2 and O2 by a fluorite/perovskite‐based membrane.

In this paper, it is reported the fabrication of a new dense ceramic‐molten carbonate membrane used for the selective separation of carbon dioxide (CO2) and oxygen (O2) at elevated temperatures (850‐950°C). First, it was chemically synthesized a fluorite/perovskite ceramic oxide with mixed ionic‐electronic conduction properties and general formula Ce0.9Pr0.1O2‐δ/Pr0.6Sr0.4Fe0.5Co0.5O3‐δ (CP‐PSFC, 60:40 wt%) by the citrate‐ethylene‐diamine‐tetra acetic acid (EDTA) route. Then, a disk‐shaped porous ceramic support partially sintered was infiltrated with a ternary mixture of molten salts of Li2CO3/Na2CO3/K2CO3 composition. The permeation measurements at high temperatures suggest a concurrent separation of both species CO2 and O2. The system exhibits high permeance of CO2 and O2 by rising to maximum values of 2.17 × 10−7 and 0.69 × 10−7 mol m−2 s−1 Pa−1, respectively at 950°C. Moreover, the possibility of modulating the permeate CO2:O2 ratio is envisaged by changing the fluorite to perovskite proportion in the membrane composition. The stability performance of the obtained membrane was studied under a long‐term permeation test. It exhibits a remarkable thermal and chemical stability during 110 h at 875°C. This way, it corroborated the proposed new ceramic phase's excellent properties for the fabrication of supported ceramic‐molten carbonate membranes. [ABSTRACT FROM AUTHOR]