第 35 卷第 3 期 高 校 化 学 工 程 学 报 Vo 5 2021 and atmospheric pressure. The accuracy of the LLE data was examined by the Othmer-Tobias equation with the linear correlation R2 ≥ 3. The LLE data of the quinary systems were regressed by the non-random two liquids (NRTL) model and related binary interaction parameters were obtained to predict the LLE data of the six-component system. The results show that the predicted values are in great agreement with experimental data, which indicates that the regressed parameters have high accuracy. Key words: butanol+octane+nonane mixture; extraction; liquid-liquid equilibrium; non-random two liquids (NRTL); Aspen Plus