Performance study of asymmetric oxygen transport membranes with vertically channelled pores by phase inversion tape casting

Abstract

Asymmetric oxygen transport membranes have been extensively studied revealing the importance of the support porosity. In this study, asymmetric membranes with vertically channelled pores were prepared from Ba0.5Sr0.5(Co0.8Fe0.2)0.97Zr0.03O3-δ (BSCF-Z) by phase inversion tape casting. The rate-limiting effects of the membrane layer thickness, the support structure, and the activation layers were thoroughly analysed. This entails comparing the permeation rate of the samples with the membrane layer on different sides of the channelled supports. Pore tortuosity and computed permeability were evaluated from 3D-X-ray computed tomography and compared to previously reported asymmetric membranes prepared by tape-casting and freeze-drying. Due to a lower pore tortuosity, the channelled supports have an advantage in gas transport over the tape cast and freeze cast supports. However, this is compensated by a thicker membrane layer (∼54 μm) resulting in similar performance compared to the thinner membrane layers (∼20 μm) with freeze cast and tape cast supports.