A conventional triple-column extractive distillation is researched for the separation of acetonitrile/isopropanol/water mixture with ethylene glycol (EG) as entrainer. In this article, the pressure-relative volatility curve is investigated to find the suitable pressure of column. To achieve the further energy saving, three heat-integrated schemes and two heat-integrated combined with intermediate reboilers schemes are researched based on the conventional extractive distillation. Both two heat integration with intermediate reboilers schemes shown the better performance than other schemes since the further analysis of the energy, exergy, economic and environment (4E) were investigated. For the most energy saving design, PHI-IHI2, it has 48.50% energy-saving, 70.73% exergy efficiency enhanced, 36.24% reduction in total annual cost (TAC) and 48.55% reduction in gas emissions with the comparison of the conventional extractive distillation (CED) process. The result shows the extractive distillation combined with heat-integrated and intermediate reboilers presented great energy-efficient, economy saving and environment friendly for separating acetonitrile/isopropanol/water mixture.

研究了传统的三柱萃取蒸馏法，以乙二醇（EG）为夹带剂，用于乙腈/异丙醇/水混合物的分离。本文研究了压力相对挥发度曲线，以找到合适的色谱柱压力。为了进一步节省能源，在常规萃取蒸馏的基础上，研究了三种热集成方案和两种热集成与中间再沸器组合方案。由于对能源，火用，经济和环境（4E）进行了进一步分析，因此与中间再沸器方案进行的两个热集成均显示出比其他方案更好的性能。对于最节能的设计，PHI-IHI2节省了48.50％的能源，提高了70.73％的火用效率，降低了36.24％的年总成本（TAC），并降低了48％。与传统的萃取蒸馏（CED）方法相比，减少了55％的气体排放。结果表明，萃取蒸馏与热集成和中间再沸器相结合，能高效，经济，环保地分离乙腈/异丙醇/水混合物。