Phase equilibrium experiment and mechanism analysis of tert‐butanol‐cyclohexane in deep eutectic solvent separation

Cyclohexane (CYH) and tert‐butanol (TBA), as necessary industrial solvents, form an azeotrope that poses significant challenges in traditional distillation separation processes and leads to energy consumption issues. In this study, six deep eutectic solvents (DESs) based on quaternary ammonium salts were prepared to effectively separate TBA and CYH. Through liquid–liquid equilibrium experiments, the distribution coefficient and selectivity of TBA in these DESs were determined. The experimental data exhibited good linear correlation with the fitting results of the Othmer–Tobias equation and Hand equation. Furthermore, the binary interaction parameters in the nonrandom two‐liquid (NRTL) model were fitted using a MATLAB program, verifying the reliability of the model for the experimental data. Finally, by combining quantum chemical calculations with molecular dynamics (MD) simulations, the underlying mechanism of DESs in TBA extraction was thoroughly elucidated at the microscopic level, providing a solid theoretical foundation for the separation of alcohol–alkane azeotropic systems.