水-乙醇-环己醇三元体系精馏分离工艺模拟及优化

SIMULATION AND OPTIMIZATION OF DISTILLATION SEPARATION OF WATER-ETHANOL-CYCLOHEXANOL TERNARY SYSTEM

利用ASPEN PLUS化工模拟软件,选择NRTL物性分析方法,以N,N-二甲基甲酰胺(DMF)为萃取剂,采用萃取精馏与减压精馏相结合的方法,对水-乙醇-环己醇三元体系的分离过程进行了模拟与优化。考察了塔板数、回流比、原料进料位置及萃取剂进料位置和用量对精馏分离过程的影响,对萃取剂与水分离塔的操作压力进行了比较与分析。结果表明:当原料处理量为10 t/h,醪液中w(水)=85%,w(乙醇)=10%,w(环己醇)=5%时,采用萃取精馏和减压精馏可以使处理后的水中乙醇质量分数小于10×10^(-6),环己醇质量分数小于30×10^(-6);回收的w(乙醇)≥99.6%,w(环己醇)≥95%。

The separation process of water-ethanol-cyclohexanol ternary system by the combination of extractive distillation and vacuum distillation using N,N-dimethylformamide(DMF)as extractant was simulated and optimized through NRTL physical property analysis method using Aspen Plus,a chemical process simulation software.The effects of plate number,reflux ratio,feed position of raw materials as well as the feed position and amount of extractant on the distillation separation process were investigated.The operating pressure of extractant and water leaving the tower were also compared and analyzed.The results showed that the ethanol content and cyclohexanol content in the treated water were less than 10×10^(-6) and 30×10^(-6) respectively,when the raw material treatment capacity was 10 t/h,water content was 85%,ethanol was 10%and cyclohexanol was 5%.The concentrations of recovered ethanol and cyclohexanol were higher than 99.6%,and 95%,respectively.The recovery of ethanol and cyclohexanol and the discharge of organic wastewater could be realized at the same time.