Separation of aromatic hydrocarbons from alkanes using ammonium ionic liquid C2NTf2 at T=298.15 K

(Liquid+liquid) equilibrium data are presented for four ternary systems of an alkane, or aromatic compound and ethyl(2-hydroxyethyl)dimethylammonium bis{(trifluomethyl)sulfonyl}imide (C2NTf2) at 298.45K: [hexane +benzene+ C2NTf2], [hexane+p-xylene + C2NTf2], and [hexane, or octane + m-xylene + C2NTf2]. The separation of aromatic hydrocarbons (benzene, or p-xylene, or m-xylene) from aliphatic hydrocarbons (hexane, or octane) is investigated by extraction with the ammonium ionic liquid. Selectivities and distribution ratios are discussed for these mixtures at constant temperature. The data were analysed and compared to those previously reported for other ionic liquids and especially for the system {hexane + benzene + [EMIM][NTf2]. The nonrandom two liquid NRTL model was successfully used to correlate the experimental tie-lines and to calculate the phase compositions of the ternary systems. The data presented indicate the suitability of C2NTf2 as a good solvent for the separation of aromatic and aliphatic hydrocarbons using solvent extraction. (C) 2007 Elsevier B.V. All rights reserved.