Extraction of allyl alcohol from its aqueous solution using two different ionic liquids: Intermolecular interaction and liquid-liquid phase equilibrium explorations

Allyl alcohol is a remarkable chemical intermediate. During its preparation by allyl acetate hydrolysis, an aqueous mixture is usually obtained. Because allyl alcohol can form a minimum boiling point azeotropic mixture with water, it is impossible to separate such a mixture by conventional distillation. In this work, for recovering allyl alcohol by extraction, the ionic liquid extractants (ILs) were adopted by the model of COSMO-SAC and two ILs 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ([BMP] [Tf2N]) and 1-octyl-3-methylimidazolium trifluoromethanesulfonate ([OMIM][OTf]) were selected. The length of the hydrogen bond and the energy of the interaction between the ILs and (allyl alcohol/water) were calculated by quantum chemical calculations. The experimental liquid-liquid phase equilibrium (LLE) data for the ternary systems (water + allyl alcohol + [OMIM][OTf]/[BMP][Tf2N]) were explored at 298.15 K. The [OMIM][OTf] and [BMP][Tf2N] extraction capability was assessed with selectivity and partition ratio. In addition, the NRTL model was used to fit the measured tie-line values. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

The study utilized ionic liquid extractants to recover allyl alcohol, investigated various interactions through calculations and experiments, evaluated the performance of the extractants, and used the NRTL model to fit the data, enhancing the efficiency of allyl alcohol recovery.