Heat Transfer Enhancement in Separation Process of Ethanol from Ethanol Water Mixture by Using Surfactants

Abstract

The investigation was conducted during the distillation of an ethanol-water mixture for separating ethanol from the fermentation process. The focus is to study the reduction in time required and, hence, the energy savings for the distillation process of the ethanol-water mixture under the influence of surface-active agents (surfactants). This novelty arises from the observation that these surfactants enhance the heat transfer rate because of surface tension reduction in aqueous solutions. Sodium Dodecyl Sulphate (SDS), NH₄Cl (Ammonium Chloride), and Sodium Lauryl Benzene Sulphonate (SLBS) surfactants in different concentrations were tested. The concentration of these surfactants was varied from 1,700 ppm to 2,800 ppm. This range was decided by observing the critical micelle concentration of the used surfactants. Results showed that time was reduced and, consequently, energy consumption was also reduced. Results shown by NH₄Cl were found to be more useful, as it is an eco-friendly surfactant which does not affect the ethanol-water mixture. The use of ammonium chloride as a surfactant in distillation is actually useful to reduce energy consumption without hampering the quality of the process, which is the novelty of this work.