Research on the Application of Ionic Liquid Extraction Agent in the Enhanced Separation of Allyl Alcohol-Water Azeotropic System

Allyl alcohol is an important chemical intermediate widely used in the synthesis of pharmaceuticals, pesticides, and perfumes. Therefore, studying the efficient separation of the azeotropic system of allyl alcohol-water has important practical significance. Based on the COSMO-RS predictive model and by using the selectivity and capacity as the evaluator, the performance of the ionic liquids as extractants for separating the azeotropic system of allyl alcohol-water were studied. First, two high-performance extractants named tetramethylammonium chloride (C12A11) and tetramethylammonium bromide (C12A12) were screened from 384 ion liquids designed by combining 16 anions and 24 cations. Second, the reliability of the model in predicting the vapor-liquid phase equilibrium behavior of the allyl alcohol-water system was verified. Then, tetramethylammonium chloride was used to investigate its effect on the vapor-liquid phase equilibrium of the allyl alcohol-water system. The results show that at a molar content of tetramethylammonium chloride of 0.1, the azeotrope of the system can be broken, which can be used for enhanced separation of the allyl alcohol-water system. On this basis, the mechanism of extractant selectivity for allyl alcohol was analyzed from the perspective of microscopic molecular interactions, providing theoretical support and data support for further designing high-performance ion liquid extractants.