Influence of fusel oil components on the distillation of hydrous ethanol fuel (HEF) in a bench column

Abstract

The components of fusel oil form azeotropes with water, resulting in challenges in obtaining hydrous ethanol fuel (HEF) and increasing investment and operating costs. The aim of this study was to evaluate how the presence of fusel oil affected HEF distillation. Mixtures of ethanol (6.0 to 6.5 % w/w) and water (93.0 to 94 % w/w) containing different concentrations (zero to 0.5 % w/w) of 3-methyl-1-butanol, 2- methyl-1-propanol, propan-1-ol and propan-2-ol were distilled in a laboratory apparatus. Under total reflux conditions, HEF concentrations in compliance with Brazilian legislation specifications were obtained, but the desired concentration could not be attained under continuous operation. All of the experiments resulted in a high loss of ethanol in the bottom product under multiple operating conditions. The results demonstrated that fusel oil affects HEF distillation, but that HEF concentrations can still be obtained in compliance with Brazilian legislation.