Abstract
In this paper, a modified solution–diffusion model is proposed to account for the mass transport of penetrants in the polymer membrane. In the model, the group contribution method (the UNIFAC-ZM model) is introduced to calculate the activity of penetrants in the polymer membrane, and a new temperature-dependence diffusion coefficient equation is developed to describe the diffusion behavior of the penetrants. The aim of this work is to establish a predictive solution–diffusion model. By refitting the group interaction parameters based on pervaperation data of penetrants-membrane systems, the model can be applied to predict the fluxes and separation factors of various polymer membrane systems. As an exemplary application of the model, the permeation fluxes and separation factors of benzene/cyclohexane mixtures in a PDMS membrane system have been predicted and shown to be in good agreement with experimental values.
