Measurement and Study on the Liquid–Liquid Equilibrium of Ionic Liquids with Aliphatic Alcohols

In this work, liquid–liquid equilibria (LLE) for several binary systems of ionic liquids with aliphatic alcohols have been measured by the cloud point method from 280 K to the boiling point of the solvent. These binary systems include 1-hexyl-3-methylimidazolium tetrafluoroborate + 1-butanol/1-pentanol/1-hexanol/isobutanol and 1-octyl-3-methylimidazolium tetrafluoroborate + 1-butanol/1-pentanol/1-hexanol/1-octanol/isobutanol. The experimental data are analyzed, and some rules for the solubility of ILs are concluded, which can provide some instructions for the extraction and separation process. The equilibrium data are correlated by the nonrandom two-liquid (NRTL) model. The interaction parameters of the model for the systems are obtained. The minimum and maximum of the overall average deviation are 0.37 % and 2.67 %, respectively.