Analysis of steric hindrance in the separation of ethanol–methyl acetate azeotropic mixture using deep eutectic solvents

Abstract The separation of azeotropes is of great significance for improving product quality, optimizing production processes, and promoting the development of related technologies. This study used quaternary ammonium salt‐based deep eutectic solvents (DESs) to separate azeotropic ethanol and methyl acetate mixtures. COSMO‐RS software was used to facilitate the screening of the extractants. The best extractant was selected from 16 hydrogen bond acceptors and 38 hydrogen bond donors, and vapor–liquid equilibrium experiments were subsequently conducted for experimental verification. This experiment demonstrated that the separation of DESs synthesized from alcohol and quaternary ammonium salt chemicals is relatively practical, with the separation effect varying according to the diols employed as hydrogen bond donors. Concurrently, quantitative calculations were employed to conduct a microscopic analysis and elucidate the underlying mechanism of spatial hindrance on the separation performance of ethanol–methyl acetate.