Mechanistic Modeling of Organic Compounds Separation from Water via Polymeric Membranes

A mathematical model considering mass and momentum transfer was developed for simulation of ethanol dewatering via pervaporation process. The process involves removal of water from a water/ethanol liquid mixture using a dense polymeric membrane. The model domain was divided into two compartments including feed and membrane. For a description of water transport in the feed solution, Maxwell-Stefan approach was used, while for mass transfer inside the membrane the molecular diffusion mechanism was assumed. The governing equations were solved numerically using finite element method. The concentration profile inside the membrane showed a linear decrease and a parabolic fully developed velocity profile was obtained on the feed side. The results also confirmed that formation of concentration layer can be easily predicted using Maxwell-Stefan approach in dewatering of organic compounds using pervaporation process.