This work is aimed at investigating the capability of a computational fluid dynamics (CFD) approach to reliably predict the fluid dynamic and the separation performances of inorganic membranes modules for gas mixture separation. The simulations are based on the numerical solution of the Navier-Stokes equations on the three dimensional domain representing quite closely the selected module geometry. The membrane is modelled as a selective layer, which allows the permeation of different components as a function of the transport mechanism and the driving force. The computational strategy is strictly evaluated by comparing the results with available experimental data. The simulation predictions show fairly good agreement with the measured permeation data and allow to recognise the critical local fluid dynamic features of the separation module. (C) 2008 Elsevier Ltd. All rights reserved.