The distillate product from the rectification column represents the stream enter­ing the ethanol dehydration scheme, where the fuel ethanol with ethanol content greater than 99.5% should be produced. To achieve this high purity from streams containing 90 to 92% ethanol, it is necessary to employ nonconventional separation

operations like pressure-swing distillation, azeotropic distillation, extractive distil­lation, adsorption, and pervaporation (Sanchez and Cardona, 2005). All of these operations have found industrial application in the fuel ethanol industry.