Abstract:The more rigorous 'dynamic method' instead of 'static method' based on UNIFAC model (modified UNIFAC model) was used to develop a program with FORTRAN language, which can be used to select solvent for extractive distillation separation of azeotropic and close-boiling mixtures and predict multi-component vapor-liquid equilibria (VLE). Verified by the VLE experimental data of ethanol-water system in the literature, this program gives the average relative deviation between the calculated gas phase equilibrium composition and that of literature 3.26% and 1.74% for UNIFAC model and modified UNIFAC model respectively, which manifests the reliability of this program. The extractive solvents to separate cyclohexane-benzene mixture were screened with high-throughput quantitatively by 'dynamic method' based on modified UNIFAC model, and the better solvents were determined based on the prediction results and feasible solvent selection principle as dichloromethane and 1,2,3-trichloropropane. The VLE data of cyclohexane- benzene-dichloromethane system at 101.325 kPa were measured through experiment, and the calculated VLE data of the systems fit well with experimental data. Dichloromethane as extractive solvent has the advantages of low energy consumption and fine heat stability of the separation system.