动态法筛选萃取精馏分离乙酸丁酯-丁醇-水共沸物的溶剂

Screening solvents by dynamic method for extractive distillation and separation of butyl acetate-1-butanol-water azeotropic mixture

采用基于改进UNIFAC模型的动态法对萃取精馏法分离乙酸丁酯-丁醇-水共沸物的萃取剂进行了计算机高通量筛选,根据适宜萃取剂选取原则和计算结果,经综合考虑选出较好的萃取剂为甲醇、乙醇、环氧乙烷。选取乙醇进行实验验证,测定了乙酸丁酯-丁醇-水-乙醇体系的部分汽液平衡实验数据;泡点温度tb、加入溶剂后平衡汽相组成的计算值与实验值吻合良好;以乙醇作为萃取剂具有热负荷小、毒性低和热稳定性好的优点。结果表明,采用基于改进UNIFAC模型的动态法筛选萃取精馏法的溶剂具有良好的可靠性和适用性,可以极大地节省人力、物力和财力。

The extractive solvents for separating butyl acetate-1-butanol-water azeotropic mixture were processed with high-throughput screening by dynamic method based on modified UNIFAC model. According to the proper solvents selection principle and the prediction results, the better extractive solvents were determined as methanol, ethanol, ethylene oxide. In the case of ethanol as extractive solvent, the vapor-liquid equilibria （VLE） data of butyl acetate-l-butanol-water-ethanol system were measured through the experiment; the calculated values of bubble point and the gas phase equilibrium composition fit well with the experimental data, and the calculated VLE data of the systems fit well with the experimental data. The ethanol as extractive solvent has the advantages of low energy consumption, low toxicity and better heat stability of the separation system. It shows that the dynamic method based on modified UNIFAC model can save much more manpower, physical resource and financial resource.