Selective Separation of Aromatics from Paraffins and Cycloalkanes Using Morpholinium-Based Ionic Liquid

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• 作者：Fan Zhang ; Yong Li ; Lele Zhang ; Wei Sun ; Zhongqi Ren
• 刊名：Journal of Chemical & Engineering Data
• 出版年：2015
• 出版时间：June 11, 2015
• 年：2015
• 卷：60
• 期：6
• 页码：1634-1641
• 全文大小：410K
• ISSN：1520-5134

文摘

Morpholinium-based ionic liquids (MILs) have attracted increasing interest because of their good extraction performance and low toxicity. In this study, two MILs, N-benzyl-N-methylmorpholinium bis(trifluoromethylsulfonyl)imide (MIL-a) and N-allyl-N-methylmorpholinium bis(trifluoromethylsulfonyl)imide (MIL-b), were synthesized. Six ternary systems, toluene鈥揾eptane鈥揑L (MIL-a or MIL-b), benzene鈥揾exane鈥揗IL (IL-a or MIL-b) and benzene鈥揷yclohexane鈥揑L (IL-a or MIL-b), were studied in terms of both quantum chemical calculation and liquid鈥搇iquid extraction. The calculation results showed that both MILs had stronger interaction with aromatics than with alkanes. For both cations of MILs, stronger binding energy was obtained with toluene than with benzene. The difference between MIL-a-toluene and MIL-a-cyclohexane was larger than that of MIL-b. As a result, MIL-a showed higher selectivity on toluene than MIL-b. In other ternary systems, the interaction difference was larger than that between MIL-a-benzene and MIL-a-alkanes, which led to a better selectivity of benzene on MIL-b. The liquid鈥搇iquid extraction experiment was conducted at 298.2 K and atmospheric pressure. The distribution coefficients of aromatic compounds (benzene and toluene) were over 0.60 when MIL-a was used as extractant, and above 0.50 when MIL-b was used. The selectivity was more than 80, and the distribution coefficient of toluene was over 1.4, when MIL-b was used in the ternary system with benzene and hexane. Both MILs could be reused without significant loss of selectivity and distribution coefficients.