Modeling of pervaporation process for the dehydration of bioethanol

The comparison of the different dewatering processes of bioethanol in basing on the literature showed that the pervaporation is very promising for the separation of azeotropes, reducing the consumption energy and protect the environment. Despite these advantages, this method has limitations concern the bioethanol production capacity and type of membrane used. In this work, we sought to develop a model that can be used to improve its production and study its performance optimization. This model is based on diffusion equations, mass and energy balance. The use of these equations requires knowledge of the thermodynamic properties such as heat capacity and enthalpy of vaporization of each component in the mixture and the excess enthalpy and the density of the mixture. For the prediction of the latter, Peng-Robinson equation of state was used for ethanol/water mixture. For other properties, we have shown that they can be calculated using simple empirical correlations based on experimental data. For simulation equations, a computer program was developed with Scilab 5.5.2. The simulation results for the dehydration of bioethanol show that output data of pervaporation unit are very sensitive to the inlet ethanol composition.