Separation of ethanol–water liquid mixtures by adsorption on a polymeric resin Sepabeads 207®

Production of alcohol by fermentation of renewable resources like plant biomass is becoming an effective method for increasing liquid clean fuel production. Hence, ethanol recovery from fermentation broths is of huge interest. The process here studied is the separation of ethanol–water mixtures by adsorption on a polymeric resin (Sepabeads 207®). The column capacities of ethanol and water as a function of liquid composition have been determined, together with the mass transfer parameters. A theoretical model for predicting the column dynamics in this system has been developed, considering the effect of mass transfer resistance in the full concentration range (between 0% and 100% ethanol). The model, based on conservation equations, has been validated with experimental data obtained in a laboratory column. It has been also applied to design a multi-column cyclic adsorption–desorption process for separating a 10% ethanol–water mixture using the polymeric resin Sepabeads 207® as adsorbent. The net ethanol product obtained is higher than using silicalite as adsorbent.

► Ethanol and water capacities, and mass transfer coefficients have been determined.
► A multi-column cyclic adsorption–desorption process has been designed.
► Estimated net ethanol product is higher for Sepabeads 207 resin than for silicalite.