In this work, densities and viscosities at atmospheric pressure and densities at high pressures of the ionic liquid, [amim]Cl (1-allyl-3-methylimidazolium chloride) were measured. The densities were evaluated by correlation with the Tait equation and the ePC-SAFT equation of state. Both relationships could describe the experimental density data over the full range of all temperatures (313-373 K) and pressures (0.1-200 MPa) within 0.007% and 0.053%, respectively. Infinite dilution partition coefficients, K-w3(infinity), of fundamental benzene derivatives (chlorobenzene, bromobenzene, benzaldehyde and benzyl alcohol) between [amim]Cl and supercritical carbon dioxide were measured at 313-353 K and 6-21 MPa. The ePC-SAFT applied as a predictive model for the experimental partition coefficient gave high deviations (>900%). However, when the ePC-SAFT was applied as a correlative model, average deviation in K-w3(infinity) were 20%. A previously proposed semi-empirical LSER-delta model could correlate the K-w3(infinity) data to within 8.9%. Separation factors of solutes in [amin]Cl-CO2 system were calculated with ePC-SAFT model and compared with literature results for [bmim]Cl-CO2 since both of these ionic liquids have application to biomass processing. For each given ionic liquid, [amim]Cl and [bmim]Cl, the separation factors of non-polar or slightly polar compounds (chlorobenzene, bromobenzene and benzaldehyde) to the reference polar compound (benzyl alcohol) were always greater than 100, with [amim]Cl-CO2 always having a higher separation factor than [bmim]Cl-CO2. Thus, [amim]Cl-CO2 can probably provide better separation between non-polar and polar mixtures than [bmim]Cl-CO2. (C) 2015 Elsevier B.V. All rights reserved.