Screening of environmental friendly ionic liquid as a solvent for the different types of separations problem: Insight from activity coefficients at infinite dilution measurement using (gas + liquid) chromatography technique

Abstract

The present work focussed on screening of the environmental friendly imidazolium-based ionic liquid for the separations of (alkane/aromatic), (alkane/alk-1-ene), (cycloalkane/aromatic) and (water/alkan-1-ol) using (gas + liquid) chromatography (GLC) technique. In this reason the activity coefficients at infinite dilution, View the MathML source?13?, for 29 organic solutes (alkanes, cycloalkanes, alkenes, alkynes, aromatics, alkanols and ketones) and water in ionic liquid 1-ethyl-3-methylimidazolium n-octylsulphate [EMIM]+[OS]? were measured at temperatures of (318.15, 333.15, 348.15 and 358.15) K. Stationary phase loadings of (23.77 and 40.76)% by mass were used to ensure repeatability of measurements. Uncertainties were determined using the law of propagation of uncertainty with an average absolute deviation of 2.53%. Density, viscosity and refractive index values were measured to confirm the purity of pure ionic liquid. Partial molar excess enthalpies at infinite dilution, View the MathML source?H1E,?, were also determined. The selectivities, View the MathML sourceSij?, and capacities, View the MathML sourcekj?, were determined for the separations of (alkane/aromatic), (alkane/alk-1-ene), (cycloalkane/aromatic) and (water/alkan-1-ol). The separating ability of the investigated ionic liquid was compared against previously investigated and industrial solvents such as sulfolane, n-methyl-2-pyrrolidine (NMP) and n-formylmorpholine (NFM).