Ba0.5Sr0.5Co0.8Fe0.2O3d (BSCF) perovskite powder was synthesized via EDTA/citrate complexation method. BSCF membranes were formed
by pressing powder at 400 MPa and sintering at 1100 8C for 10 h. XRD patterns showed that a high pure powder with cubic structure was obtained.
SEM micrographs revealed that the membranes are dense with large grains. Effects of temperature, feed and permeate side oxygen partial
pressures, flow rates and membrane thickness on oxygen permeation flux were studied experimentally. A Nernst–Planck based mathematical
model, including surface exchange kinetics and bulk diffusion, was developed to predict oxygen permeation flux. Considering non-elementary
surface reactions and introducing system hydrodynamics into the model resulted in an excellent agreement (RMSD = 0.0617, AAD = 0.0487 and
R2 = 0.985) between predicted and measured fluxes. The results showed that oxygen permeation flux increases with temperature, feed side oxygen
partial pressure and flow rates, however decreases with permeate side oxygen partial pressure and membrane thickness. Contribution of feed side
surface exchange reactions, bulk diffusion and permeate side surface exchange reactions resistances in the total resistance are in the range of 8–
32%, 10–81% and 11–59%, respectively. Permeation rate-limiting step was determined using the membrane dimensionless characteristic
thickness.