A comprehensive computational fluid dynamics simulation was developed for the rational design of a bioethanol purification system using a pervaporation process by tailoring the hydrodynamics of the process. The process involves the removal of water from a water/ethanol liquid mixture using a dense polymeric membrane. The model domain was divided into two compartments comprising the feed and the membrane. To describe water transport in the feed solution, the Maxwell-Stefan approach was used, whereas for mass transfer inside the membrane the molecular diffusion mechanism was adopted. The governing equations were solved numerically by using a finite element method. The model was capable of predicting mass transfer along with momentum transfer in the feed and membrane compartments.