化工学报2017，Vol.68Issue(11)：4186-4200,15.DOI:10.11949/j.issn.0438-1157.20170159
萃取精馏复合溶剂的复配选择
Combination of mixed solvent in extractive distillation
摘要
Abstract
Extractive distillation is an effective separation process to deal with the separation of close-boiling compounds and azeotropic systems. The selection of appropriate solvent is the key factor for feasibility and economy in extractive distillation. A new method of screening mixed solvent of extractive distillation was proposed, which was according to the situation of forming the hydrogen bond and modified UNFAC model. To take the polar systems (ethyl acetate-ethanol, ethanol-water) and non-polar system (cyclohexane-benzene) as examples, the appropriate mixed-solvents and the optimal proportion were sought out. The vapor-liquid equilibrium data of solvents (single-solvents and mixed-solvents) and azeotropic system were determined by modified Othmer kettle. The results showed that the calculated values were in good agreement with the experimental data and the relative error was less than 9%. By taking into the synthetical evaluation to the solvents, the optimal mixed solvents to separate ethyl acetate-ethanol, ethanol-water, and cyclohexane-benzene were obtained respectively. Under the action of optimal mixed-solvent, the relative volatility of feed components reached maximum which was higher than the value by using any single solvent. At different feed components the trend of volatility of feed components changed by a mixed solvent was almost the same, which indicated that the mixed solvent could improve the volatility of feed components in any tray of extractive distillation column efficiently.关键词
萃取精馏/复合溶剂/共沸(混合)物/相平衡/分离Key words
extractive distillation/compound solvents/azeotrope/phase equilibria/separation分类
化学化工引用本文复制引用
方静,轩碧涵,李晓春,李春利..萃取精馏复合溶剂的复配选择[J].化工学报,2017,68(11):4186-4200,15.基金项目
教育部博士点基金项目(20131317120014). supported by the Research Foundation for the Doctoral Program of China (20131317120014). （20131317120014）
