The application of 3D imaging techniques, simulation and diffusion experiments to explore transport properties in porous oxygen transport membrane support materials

We conclude, that image and simulation based methodologies arrive at lower tortuosity values in comparison to diffusion cell experiments; the difference, depending on the calculation method, can be close to a factor of two. The difference may stem from Knudsen diffusion effects which currently are not accounted for in the image based modelling techniques. Moreover, tortuosity values extracted via diffusion cell experiments are a function of gas mixture and temperature. As a result, one has to distinguish between geometric tortuosity and diffusive tortuosity used for quantifying the resistance of a structure to a flux.