Bioethanol is an extremely important raw material on the world market that is used in various industries. The purification processes most commonly used in modern biorefineries include distillation for ethanol extraction, followed by zeolite adsorption for bioethanol dehydration. Both processes are very energy-intensive. Membrane separation processes have significant potential to replace both steps in bioethanol production, which could significantly lower operating costs and reduce production costs. This paper describes the implementation of pervaporation and vapour permeation in the bioethanol dehydration process. The aim is to increase the ethanol concentration from 96% vol. at the outlet of the distillation column to over 99% vol. by using hydrophilic membranes that are able to selectively pass water molecules and thus remove them from the bioethanol. Based on the existing literature, the study determines the optimal process parameters such as temperature, pressure, flow rate, and pressure on the permeate side. Furthermore, the performance of different organic, inorganic, and composite membranes is presented, and the maintenance of these parameters, as well as the decreasing performance of the materials during prolonged use, is discussed.
Erdes et al. (Thu,) studied this question.