Effect of Solvent Cation Alkyl-Chain Length on the Separation of Butylbenzene from n-Tetradecane Using Hexafluorophosphate-Based Ionic Liquids at (313.15 and 333.15) K and 101.3 kPa

Abstract

The extraction of butylbenzene from n-tetradecane using three ionic solvents ([bmim][PF 6 ], [hmim][PF 6 ], and [omim][PF 6 ]) was studied at two temperatures (313.15 and 333.15 K) and under atmospheric pressure (101.3 kPa). Experimentally determined distribution coefficients (K) and solvent selectivities (S) were plotted against the mole fraction of butylbenzene in the solvent phase; improved results were obtained compared to the conventional solvent, sulfolane. The distribution coefficient and selectivity both increased with increasing alkyl chain length of the 1-alkyl-3-methylimidazolium moiety of the solvent cation. The universal quasichemical model was satisfactorily applied for correlating the experimental liquid−liquid equilibrium data of all three systems. Furthermore, comparison with literature results revealed that the distribution coefficients decreased with increasing paraffin carbon number.

Separation of Alkylbenzenes from n-Heptane Using Binary Mixtures of Ionic Solvents

“…The samples from the ionic and aliphatic-rich layers were collected, weighed, and then analyzed using an Agilent gas chromatograph/mass selective detector system (GC/MSD 7890B) coupled with an Agilent autosampler (7693). The detailed measurement and analysis of phase composition is dicussed in a previously published work …”

“…The detailed measurement and analysis of phase composition is dicussed in a previously published work. 50 widely used for evaluating the feasibility of using a solvent in a liquid extraction process. The K value represents the ability of the solvent to extract propylbenzene, butylbenzene, or p-xylene from the n-heptane-rich phase.…”