萃取精馏分离丙醇-水-乙酸丙酯混合物

Separation of propanol-water-propyl acetate mixture by extractive distillation

为挑选萃取精馏分离丙醇-水-乙酸丙酯混合物较好的溶剂,采用基于UNIFAC模型的动态法对待选溶剂进行了计算机高通量筛选。根据加入溶剂后体系互溶性和相对挥发度大小的预测结果,经综合考虑选出较好的萃取剂为丁醇和甲醇。选取丁醇为溶剂做实验验证,测定了丙醇-水-乙酸丙酯-丁醇体系的部分汽液平衡实验数据;泡点温度tb、加入溶剂后的相对挥发度α和平衡气相组成yi的计算值与实验值吻合良好,这表明采用基于UNIFAC模型的动态法筛选萃取精馏的溶剂具有良好的可靠性和适用性。

In order to select the better solvents for the separation of propanol-water-propyl acetate mixture by extractive distillation,the possible solvents were screened quantitatively with high-throughput screening by dynamic method based on UNIFAC model.According to the results of phase stability analysis and the calculated relative volatility values,butanol and methanol were determined as the better extractive solvents.Taking butanol as extractive solvent,the vapor-liquid equilibria data of propanol-water-propyl acetate-butanol system at normal pressure were measured through the experiment;the calculated values of bubbling point temperature tb,relative volatility α and gases phase equilibrium composition yi fit well with that of experimental data,which shows that screening solvents by dynamic method based on UNIFAC model has the advantages of good reliability and feasibility.