Pervaporation: a case-study problem. Pervaporation refers to removal of the permeate as vapor and represents an intermediate case between purely gas transport and purely liquid transport in a membrane. The process is important in production of pure ethyl alcohol,which can otherwise be done only by a more expensive azeotropic distillation. Additional information on this process may be found in the book by Seader et al. (2001).
The purpose of this problem is to establish a model for the pervaporation process. Develop a model assuming equilibrium conditions both on the upstream liquid side and on the downstream gas side. Also assume that the permeate diffusion is controlled by Fick's law. The effective partial-pressure driving force may be used for transport, but the upstream side is at higher pressure, and an activity correction needs to be used here. Develop a model based on these concepts.