title: Separation of benzene and hexane by solvent extraction with 1-alkyl-3-methylimidazolium bis{(trifluoromethyl)sulfonyl}amide ionic liquids: effect of the alkyl-substituent length.
abstract: The influence of the alkyl-substituent chain in 1-alkyl-3-methylimidazolium bis{(trifluoromethyl)sulfonyl}amide ionic liquids ([C(n)mim][NTf(2)], where n is the length of a linear alkyl chain) as solvents for the separation of benzene and hexane by liquid extraction was investigated. The liquid-liquid equilibrium (LLE) at 25 degrees C for the ternary systems ([C(n)mim][NTf(2)] + hexane + benzene), with n taking the values 4, 8, 10, and 12, were determined. These data were analyzed and compared to those previously reported for the system ([C(2)mim][NTf(2)] + hexane + benzene). The results show that short alkyl chains on the imidazolium cation of the ionic liquid lead to a better extractive separation of benzene and hexane, and reveal the influence of the relative degree of ordering in the ionic liquids on the extraction parameters.
authors.affiliation: Department of Chemical Engineering, University of Santiago de Compostela, E-15782 Santiago de Compostela, Spain.
authors.forename: Alberto
authors.initials: A
authors.lastname: Arce
authors.forename: Martyn J
authors.initials: MJ
authors.lastname: Earle
authors.forename: Héctor
authors.initials: H
authors.lastname: Rodríguez
authors.forename: Kenneth R
authors.initials: KR
authors.lastname: Seddon