Mass transfer in supported liquid membranes: A rigorous model

A rigorous steady-state model for the facilitated solute transport across ceramic-tube-supported liquid membranes is presented. The proposed permeation model accounts for the effect of the variation of the distribution coefficient, as well as nonconstant solute concentration in the strip phase and nonequilibrium interfacial reactions. The resulting convection-diffusion transport equations form a set of boundary-coupled partial differential equations. 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 that must be considered when designing or analyzing the performance of supported liquid membrane modules. The model is also used to examine the effect of key operating conditions on the module's performance. (C) 2000 Elsevier Science Ltd. All rights reserved.