Investigation of Mole Fraction Profile in Pervaporation Process Using CFD Simulation

Investigation of Mole Fraction Profile in Pervaporation Process Using CFD Simulation

In the recent years, separation of aromatic/aliphatic mixtures using membrane separation technologies is being investigated extensively, and pervaporation (PV) is considered as a basic unit operation for separation of these mixtures. PV is a process in which separation of a desired component takes place through a dense membrane via solution-diffusion mechanism. In this work, some experiments were performed to investigate pervaporation separation of toluene/n-heptane mixtures and a comprehensive mathematical model was developed to predict unsteady state transport of these mixtures through the membrane in a PV batch. Conservation equations which including continuity, momentum and mass transfer equations were solved using finite element method (FEM) and computational fluid dynamics (CFD) technique was applied to solve the model equations. The model was then verified using the PV experimental data obtained using composite membrane. The simulation results were in good agreement with the experimental data for a feed with 25 mol% of toluene, at a temperature of 85 °C and at a vacuum pressure of 2 mbar. The modeling results also presented toluene mole fraction profile in the module. The simulation results described that the developed model could provide a general simulation of transport in the PV process.