隔壁塔萃取精馏及共沸精馏分离异丙醇-水体系的模拟与优化

Simulation and optimization of isopropyl alcohol-water separation by extractive distillation and azeotropic distillation in dividing wall column

分别采用隔壁塔萃取精馏(EDWC)与隔壁塔共沸精馏(ADWC)工艺制取无水异丙醇(IPA),借助Aspen Plus模拟软件建立二塔等价模型,利用灵敏度分析对主塔进料位置、夹带剂用量、侧线采出位置、侧线采出量及回流比等参数进行优化,结合塔的设计规范,以此确定最佳工艺参数。模拟结果显示,与常规双塔工艺流程相比,在完成相同的分离要求下,EDWC工艺的冷凝器和再沸器热负荷分别降低32.38%,12.39%,设备费用和总年度费用分别节约29.34%,4.87%;ADWC工艺的冷凝器和再沸器热负荷分别降低29.57%,23.41%,设备费用和总年度费用分别节约16.87%,22.41%。ADWC用于制取无水IPA在节能降耗及节约设备成本方面表现出明显的优势。

Anhydrous isopropyl alcohol(IPA)was prepared by extractive distillation dividing wall column(EDWC)process and azeotropic distillation dividing wall column(ADWC)process,respectively.A two-tower equivalent model was established by Aspen Plus simulation software.The process parameters such as feed stage,entrainer amount,side-draw stage,side-draw amount and reflux ratio of the main column were optimized by sensitivity analysis,and the optimum parameters were determined according to the column design specifications.The simulation results show that compared with the conventional two-tower process,the heat load of the condenser and reboiler in the EDWC process is reduced by 32.38%and 12.39%,respectively,the equipment cost and the total annual cost is saved 29.34%and 4.87%,respectively.The heat load of the condenser and reboiler in the ADWC process is reduced by 29.57%and 23.41%,respectively,the equipment cost and the total annual cost is saved 16.87%and 22.41%,respectively.The ADWC for preparation of anhydrous IPA has obvious advantages in energy saving and equipment cost saving.