Computational molecular engineering of ionic liquids for <scp>CO₂</scp> drying: Design strategies and molecular mechanisms

Abstract Gas drying, as an important unit operation in the field of chemical engineering, is critically dependent on the selection of an efficient solvent. In this work, a computer‐aided ionic liquid design method was used to design ionic liquids for CO 2 drying. A candidate ionic liquid was synthesized, and its drying performance was experimentally evaluated based on the saturated vapor pressure of H 2 O and the solubility of CO 2 . A random forest model was trained to predict CO 2 solubility in ionic liquids. SHAP analysis was used to explore the impact of different ionic liquid structures on solubility. Quantum chemical calculations and molecular dynamics simulations were used to investigate the types of intermolecular interactions, interaction locations, and molecular distribution at the gas–liquid interface. The results indicate that the determined ionic liquid has excellent drying potential, with strong hydrogen bonding between the anion and water playing a dominant role in the separation process.