New Resistance Model for Interpretation of Gas Permeation Data of Composite and Asymmetric Membranes

In this work a new resistance model has been presented based on that of Henis-Tripodi which can be used for interpretation of gas permeation data in composite and asymmetric membranes. In contrast to the previous works, in this model the fraction of the support layer surface that includes the pores filled with coating material has been taken into account. The influences of the filled pores on separation factor and the gas permeation through composite and asymmetric membranes as well as the influence of the effective thickness of substrate on the filled pores have also been analyzed. Then the corresponding unknown parameters for gas separation of the composite and asymmetric membranes have been characterized by nonlinear regression and the results were compared with those of the experimental data from the literature. The pressure dependence of the gas permeability coefficient in glassy polymer has also been considered. The model shows improvement with respect to its capability in the interpretation of the permeation data of gas mixtures by composite and asymmetric membranes.