Ionic liquids enable sustainable separation of low‐carbon alcohol/water: Thermodynamic insights and process development

The efficient and clean separation of ternary azeotropes such as methanol/ethanol(ET)/water(H 2 O) poses a significant challenge in the chemical industry. This study employed COSMO‐RS to screen 1‐ethyl‐3‐methylimidazolium dimethylphosphate ([EMIM][DMP]) from 247 ionic liquids for MT /ET /H 2 O separation. The separation mechanism was elucidated through quantum chemical calculation and molecular dynamics simulations. Based on this, three separation sequences were constructed. A genetic algorithm optimized it across total annual cost, CO 2 emissions, and process stream index. To reduce energy consumption, these three optimized separation sequences were subjected to an intensified design, and the energy‐saving potential of different separation sequences was thoroughly investigated, ultimately resulting in nine intensified processes. Among these, heat integration‐double heat pump extractive distillation process C and heat integration‐double heat pump extractive distillation process A demonstrated the best economic and environmental performance, respectively. The cost‐effective green strategy proposed in this study is also applicable to other ternary systems.