Efficient separation in n‐butyl ether production process from computational thermodynamics to process intensification

Abstract Biobutanol is a green solvent commonly used as gasoline additive. In this study, it is proposed the separation of azeotropic mixtures of butanol and n‐butyl ether (DBE) using ionic liquids (ILs). Suitable anions [AC] − and [H 2 PO 4 ] − were screened by COSMO‐RS, and the effect of carbon chain length on the separation effect was investigated using quantum chemical calculations. It was found that the anion was primarily responsible for the separation effect, which grew as the carbon chain grew. Molecular dynamics simulations were used to verify the separation performance of the selected ILs. The separation effect of ILs was further verified using vapor–liquid phase equilibrium (VLE) experiments. The extractive distillation process with [PrMIM][AC] as the extractant was investigated to demonstrate the feasibility of ILs for the separation of butanol and DBE. This study analyzes the whole process from microscopic mechanism of action, which provides new ideas for the separation of alcohol‐ether systems.