乙醇-水-l,3-二甲基咪唑磷酸二甲酯盐三组分物系的汽液平衡测定及关联

Determination and Correlation of Vapor-Liquid Equilibrium for Ethanol-Water-1,3-Dimethylimidazolium Dimethylphosphate Ternary System

在101.32 kPa下,用CE-2型Othmer汽液平衡釜测定了乙醇-水-1,3-二甲基咪唑磷酸二甲酯盐([mmim]DMP)物系的等压汽液平衡数据;采用UNIFAC方程对实验数据进行了关联。实验结果表明,UNIFAC方程可用于含离子液体物系的汽液平衡的计算;加入离子液体[mmim]DMP使乙醇-水二组分物系的汽液平衡线发生偏离,[mmim]DMP含量越高,汽液平衡线偏离程度越大;[mmim]DMP具有明显的盐析效应,能消除乙醇-水二组分物系的共沸点;[mmim]DMP可作为乙醇-水物系萃取精馏的溶剂。

Isobaric vapor-liquid equilibrium for ethanol-water-1,3-dimethylimidazolium dimethyl-phosphate（DMP） ternary system was measured at 101.32 kPa using modified Othmer equilibrium still.The experiment results showed that the ionic liquid DMP exhibited notable salt-out effect which could enhance the relative volatility.When the mole fraction of DMP amounted to 5%,the azeotropic point disappeared and the relative volatility of the system increased with the increase of the mole fraction of DMP.UNIFAC equation was used to correlate and predict the experimental data.As a result,DMP can be taken on as a solvent of the extractive distillation for ethanol-water system.