CFD modeling of hydrophobic pervaporation process: ethanol/water separation

The computational fluid dynamics (CFD) approach was employed to model the pervaporation separation of ethanol from its aqueous solutions with polydimethylsiloxane (PDMS) membrane. The proposed CFD model was also used to describe the influences of feed flow rate, temperature, and ethanol concentration on the membrane performance. This approach is based on solving the conservation equations including continuity and momentum equations that were disceritized using finite element method for ethanol in the membrane module. The model was then validated using the experimental data obtained from pervaporation experiments. The simulation results were in good agreement with the experimental data for different values of feed concentration, feed temperature, and Reynolds number (feed flow rate). The CFD results also indicated that as feed temperature and ethanol concentration in the feed solution increased, the ethanol flux enhanced. The feed flow rate was shown to have no significant effect on ethanol flux whereas the feed concentration and temperature had highly significant effects. The developed model is able to predict the mass transport in the feed and membrane sides.