Study of the Fusel Oil Distillation Process

Fusel oil is a byproduct obtained from bioethanol distilleries, composed of a mixture of higher alcohols such as isoamyl alcohol, isobutyl alcohol, and others. This study aimed to evaluate the industrial distillation process of fusel oil to obtain isoamyl alcohol using the Aspen Plus simulator, considering fusel oil as a mixture of nine components. Fusel oil samples collected in Brazilian industrial mills were analyzed by gas chromatography. An investigation of phase equilibrium (vapor–liquid equilibrium and liquid–liquid equilibrium) was carried out for the components involved in this mixture. Three configurations for the fusel oil separation process were proposed. The best design with minimum total annual cost (TAC) resulted in a recovery of 99.53% of isoamyl alcohol of product containing the isomers isoamyl alcohol (0.818 w/w) and active amyl alcohol (0.178 w/w). Dynamic control of this configuration was investigated, and the results show that reasonable control performance can be achieved.