Evaluation of ionic liquids as solvent for aromatic extraction: Experimental, correlation and COSMO-RS predictions
For the study of the separation of benzene or toluene from octane, nonane and cyclooctane, the ionic liquids 1-butyl-3-methylimidazolium methylsulfate, BMimMSO 4 , and 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, BMimNTf 2 , were used as solvents. The (liquid + liquid) equilibria of the ternary systems {octane, or nonane, or (cyclooctane + benzene + BMimMSO 4 )}, and {(nonane + toluene + BMimMSO 4 ) or BMimNTf 2 } at T  = 298.15 K were determined, and an analysis of the influence of the structure of each compound was carried out. Besides, the experimental data have been compared with literature data with sulfolane as solvent. The experimental results obtained have been correlated using NRTL and UNIQUAC models. Finally, COSMO-RS has been used to predict the (liquid + liquid) equilibrium of the systems studied. The differences between the predicted and experimental values were used to evaluate the ability of the COSMO-RS model to describe the impact of the structure of the alkane, aromatic and ionic liquid on the (liquid + liquid) equilibria.