Computer-aided ionic liquids design and molecular insight for chloromethane dehydration

Abstract

In the process of butyl rubber production, excessive water content in chloromethane has a significant impact on the conversion and molecular weight distribution of the products. In this work, a computer-aided ionic liquids design method was used for solvent design in the chloromethane dehydration process. The generate-and-test method was utilized to solve the mixed-integer nonlinear programming problem formed in the design process. A multilayer perceptron was trained to predict the surface tension of ionic liquids. Quantum chemical calculations and molecular dynamics simulations were employed to test the dehydration performance of several designed ionic liquids. A candidate was selected for experimental synthesis and characterization. The impact of different ionic liquids on the vapor–liquid equilibrium of water was measured to confirm the feasibility, which indicates that the designed ILs exhibit a better dehydration potential compared to the basement solvent, 1-Ethyl-3-methylimidazolium tetrafluoroborate. Anions play a leading role in the dehydration process.