2-Dimensional membrane separator modelling: mass transfer by convection and diffusion

Hydrogen selective membranes may present a technologically and economically efficient method for the separation of H-2 from CO2 in pre-combustion decarbonisation of power production from fossil fuels. Accurate scale-up and performance prediction of membranes strongly depends on adequate representation of the prevailing resistances to mass transfer, especially for present-day high flux membranes. In a series of experiments, H-2/N-2 separation is measured as a function of feed flow and retentate pressure for a supported palladium membrane enclosed by annular channels for feed/retentante and sweep/permeate flow. Comparison of model predictions with measured data reveals that mass transfer resistances in the gas phase are significantly reduced by a radial velocity component in cases of high transmembrane flux, which can only be adequately described by a 2D model. For accurate interpretation of experiments, scale-up, and design of modules with high flux membranes, 2D modelling is required. (C) 2011 Published by Elsevier Ltd.