The role of molecule cluster on the azeotrope and boiling points of isooctane-ethanol blend

This study aims to assess the fraction of the isooctane-ethanol blend which has azeotrope condition. Isooctane was selected as a conventional fuel. Isooctane-ethanol blend with various mixture fractions is given the heat to obtain the distillation temperature curve and the fuel vapor. The blended fraction is varied from 0, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90 and 100% v/v ethanol to predict the condition (near) azeotrope fuel blend. Molecular analysis was used to verify the predicted azeotrope mixture of isooctane-ethanol. The results show that the isooctane ethanol blend has an azeotrope mixture at exactly on the ethanol fraction of 41.48% v/v. In this fraction blended, two polar molecules of ethanol induce a nonpolar molecule of isooctane to form a molecular cluster.