Liquid-liquid equilibria of binary systems {benzene + [x-Mim][NTf2] ionic liquid}: Experimental data and thermodynamic modeling using a group contribution equation of state

E.J. GONZALEZ; E.A. MACEDO; A. DOMINGUEZ; S.B. BOTTINI; S. PEREDA

Puerto Iguazu

Congreso; 13th International Conference on Properties and Phase Equilibria forProducts and Process Design; 2013

Ionic liquids (ILs) are relatively new class of molten salts with many novel and promising properties. Detailed knowledge of their phase behavior is required to a better understanding of the behavior of these substances and to design future technological processes. Furthermore, considering the large number of ILs that can be synthetized, methods to predict their phase behavior are crucial. In this work, liquid-liquid equilibrium (LLE) for binary mixtures {benzene (1) + ionic liquid (2)} was experimentally determined from T = (293.15 K to 333.15) K and atmospheric pressure. The ILs included in this work were 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [EMim][NTf2], and 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [HMim][NTf2]. The experimental results show that an increase of the alkyl chain length of the cation results in a higher solubility of benzene in the studied ILs. Furthermore, the group contribution equation of state(GC-EoS)was applied to model the phase behavior of binary systems of benzene mixed with ILs of the homologous family 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [x-Mim][NTf2]. New pure group parameters for the ionic liquid functional group MimNTf2 and interaction parameters between this group and the paraffin (CH3, CH2) and aromatic (ACH) groups were obtained. The GC-EOS extended with the new parameters was applied to predict LLE and VLE of binary mixtures {alkane, or benzene+ x-MimNTf2} and LLE of ternary systems {hexane + benzene + x-MimNTf2}. The results show that the GC-EOS is capable of predicting the phase behavior of this kind of mixtures with reasonably well accuracy.