Extraction of linear C4 – C6 alcohols from water by hydrophobic deep eutectic solvents: Experimental and mechanistic study

This study developed a multiscale framework for screening green extractants to separate linear C4–C6 alcohols from water. The COSMO‐RS screened 103 hydrophobic deep eutectic solvent (HDES) components, and liquid–liquid extraction experiments identified Thy‐Dec(1:1) as optimal for extracting 1‐butanol (But), 1‐pentanol (Pen), and 1‐hexanol (Hex), with extraction efficiencies of 95.14%, 99.26% and 99.87%, respectively. Random Forest analysis revealed key σ‐profile segments governing extraction performance. Liquid–liquid equilibrium (LLE) experiments confirmed Thy‐Dec(1:1)'s high efficiency, with separation increasing alongside alcohol chain length. Notably, distribution coefficient and selectivity for Hex reached 133 and 3829, respectively. The NRTL model successfully correlated all experimental data. Quantum chemical (QC) calculations and molecular dynamics (MD) simulations elucidated the mechanism: Thy‐Dec(1:1)'s strong hydrophobicity and dual interactions (hydrogen bonding and van der Waals forces) enable efficient extraction, primarily driven by van der Waals interactions with decanoic acid playing a central role.