Modeling of single- and multi-stage extraction in the system of water, acetone, butanol, ethanol and ionic liquid

This paper investigates liquid-liquid equilibrium (LLE) in the mixture of acetone, butanol, ethanol (ABE) and water in combination with three hydrophobic ionic liquids:1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [bmim][Tf2N],1-hexyl-3-methylimidazolium hexafluorophosphate [hmim][PF6];and 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulphonyl)imide [bmp][Tf2N].To model the LLE, the non-random two-liquid (NRTL) equation was used. The experimental data were taken from the cited work of Kamiński et al. (2014), where the unknown equation parameters had been determined with the help of Matlab programming. In this work, however, Aspen Plus™ software was employed as it readily facilitates further simulations of the extraction step. Different yet similarly accurate sets of the NRTL parameters were obtained. After the model formulation, single-stage and multi-stage extraction processes were simulated and examined in terms of ABE recovery effects.