Mass transfer in supported liquid membranes: A rigorous model

A rigorous steady-state model for the facilitated solute transport across c eramic-tube-supported liquid membranes is presented. The proposed permeatio n model accounts for the effect of the variation of the distribution coeffi cient, as well as nonconstant solute concentration in the strip phase and n onequilibrium interfacial reactions. The resulting convection-diffusion tra nsport equations form a set of boundary-coupled partial differential equati ons. As a case system taken from hydrometallurgy, the extraction of copper using ceramic tubes impregnated with LIX-84 as a carrier is considered. It is shown that the variation of the distribution coefficient is a factor tha t must be considered when designing or analyzing the performance of support ed liquid membrane modules. The model is also used to examine the effect of key operating conditions on the module's performance. (C) 2000 Elsevier Sc ience Ltd. All rights reserved.