用亲水性离子液体分离乙酸乙酯和乙醇.doc

SEPARATIONS Separation of Ethyl Acetate - Ethanol Azeotropic Mixture Using Hydrophilic Ionic Liquids Dong L. Zhang, 2,3 Yue F. Deng, 2 Chuan B. Li, 3 and Ji Chen* ,2 Key laboratory of Rare Earth Chemistry and Physics, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, China, and College of Chemistry, Jilin Normal Uni V ersity, Siping, 136000, China The separation of ethyl acetate and ethanol (EtOH) is important but difficult due to their close boiling points and formation of an azeotropic mixture. The separation of the azeotropic mixture of ethyl acetate and EtOH using the hydrophilic ionic liquids (ILs) 1-alkyl-3-methylimidazolium chloride (alkyl ) butyl, hexyl, and octyl) ([C n mim]Cl, n) 4, 6, 8) and 1-allyl-3-methylimidazolium chloride and bromide ([Amim]Cl and [Amim]-Br) has been investigated. Triangle phase diagrams of five ILs with ethyl acetate and EtOH were constructed, and the biphasic regions were found as follows: [Amim]Cl > [Amim]Br > [C 4 mim]Cl > [C 6 mim]Cl > [C 8 mim]Cl. The mechanisms of the ILs including cation, anion, and polarity effect were discussed. The results showed that the hydrophilic ILs [C n mim]Cl (n) 4, 6, 8), [Amim]Br, and [Amim]Cl could remove EtOH effectively from the azeotropic mixture of ethyl acetate and EtOH. Moreover, it was found that [Amim]Cl had the highest extraction efficiency, and the purity of