Mass Transport Phenomena in Pervaporation Processes

Abstract
Transport in pervaporation takes place in a three-step sequence: 1) (selective) sorption into the membrane, 2) diffusion through the membrane, and 3) desorption into a vapor phase. Diffusion through the membrane is the rate-determinating step. The transport can be described by a solution-diffusion mechanism where the permeation rate is a function of solubility and diffusivity. The basic principles of this model are described. In the case of a liquid mixture, two aspects have to be distinguished with respect to selective transport: flow coupling and thermodynamic interaction. Both aspects are discussed.