Multichannel mixed-conducting hollow fiber membranes for oxygen separation

Significance: A multichannel mixed-conducting hollow fiber (MMCHF) membrane, 0.5 wt % Nb₂O₅-doped SrCo_0.8 Fe_0.2O_3-δ (SCFNb), has been successfully prepared by phase inversion and sintering technique. The crystalline structure, morphology, sintering behavior, breaking load, and oxygen permeability of the MMCHF membrane were studied systematically. The MMCHF membrane with porous-dense asymmetrical microstructure was obtained with the outer diameter of 2.46 mm and inner tetra-bore diameter of 0.80 mm. The breaking load of the MMCHF membrane was 3-6 times that of conventional single-channel mixed-conducting hollow fiber membrane. The MMCHF membrane showed a high oxygen flux which was about two times that of symmetric capillary membrane at similar conditions as well as a good long-term stability under low oxygen partial pressure atmosphere. This work proposed a new configuration for the mixed-conducting membranes, combining advantages of multichannel tubular membrane technology and conventional hollow fibers.