Purification of hexane with effective extraction using ionic liquid as solvent

The separation of hexane and ethanol is valuable but difficult due to the formation of an azeotropic mixture. This work demonstrates the ability of the ionic liquid (IL) 1-butyl-3-methylimidazolium methyl sulfate [BMIM][MeSO4] to act as an extraction solvent in petrochemical processes for the removal of hexane from its mixture with ethanol. Knowledge of the phase behavior of the system is key in order to optimize the separation process. For this reason, the experimental liquid–liquid equilibrium (LLE) for the ternary system hexane + ethanol + [BMIM][MeSO4] is investigated at 298.15 K. The separation sequence of the extraction process is checked by using conventional software for simulation. Experimental data are obtained in a laboratory-scale packed column extraction system for the separation of this azeotropic mixture by using [BMIM][MeSO4]. It is concluded that this IL has the highest extraction efficiency.