Fluid dynamic modeling of oxygen permeation through mixed ionic–electronic conducting membranes

The oxygen transport in a lab-scale experimental set-up for permeation testing of oxygen transport membranes has been modeled using computational fluid dynamics using Finite Element Analysis. The modeling considered gas hydrodynamics and oxygen diffusion in the gas phase and vacancy diffusion of oxygen in a perovskite disc-shaped membrane at 1273 K. In a first step, the model allowed obtaining the coefficient diffusion of oxygen. The parametric study showed that the set-up geometry and flow rate in the air compartment did not have major influence in the oxygen transport. However, very important polarization effects in the sweep-gas (argon) compartment were identified. The highest oxygen permeation flux and the lowest oxygen concentration on the membrane surface were obtained for the following conditions (in increasing order of importance): (1) a large gas inlet radius; (2) short gas inlet distance; and (3) a high gas flow rate.

► Computational fluid dynamics allowed obtaining the coefficient diffusion of oxygen.
► Concentration polarization effect in permeate compartment.
► Sweep-gas flow rate and inlet distance to membrane are crucial.