Oxygen permeability and CO2-tolerance of Sr(Co0.8Fe0.2)0.8Ti0.2O3−δ hollow fiber membrane

Perovskite-type Sr(Co0.8Fe0.2)0.8Ti0.2O3−δ (SCFT20) hollow fiber membrane was prepared using the phase inversion spinning/sintering method. The hollow fiber became permeable to oxygen at elevated temperatures. At 950 °C, an oxygen permeation flux of 1.4 × 10−6 mol cm−2 s−1 was observed with a hollow fiber membrane of length 20.00 mm, outer diameter 2 mm, wall thickness 0.3 mm by exposing its shell side to the ambient air and sweeping its core side with high purity helium at a rate of 30 cm3 min−1. The hollow fiber exhibited lower, yet reasonably stable oxygen permeation flux when its core side was swept with CO2. The oxygen permeation of the membrane could be recovered to a large extent by temporarily switching off the CO2 sweep gas. The lower oxygen permeation flux under air/CO2 gradient compared with the air/He gradient was attributed to the partial decomposition of SCFT20 caused by the reaction with CO2.

Research highlights▶ The SCFT20 membrane is fabricated into hollow fiber geometry. ▶ The hollow fiber allows oxygen to permeate at faster rate than the disk-shaped membrane. ▶ The oxygen permeation performance of the hollow fiber degrades gradually when its core side is swept with 100% of CO2, which however can be recovered to a large extent by temporarily switching off the CO2 sweep gas.