Liquid-liquid equilibria of water + ethanol + reformate

Liquid-liquid equilibria (LLE) of the multicomponent system water + ethanol + a synthetic reformate (composed of benzene, n-hexane, 2,2,4-trimethylpentane, and cyclohexane) was studied at atmospheric pressure and at 283.15 and 313.15 K. The mutual reformate-water solubility with addition of anhydrous ethanol was investigated. Different quantities of water were added to the blends in order to have a wide water composition spectrum, at each temperature. We conclude from our experimental results, that this multicomponent system presents a very small water tolerance and that phase separation could result a considerable loss of ethanol that is drawn into the aqueous phase. The results were also used to analyse the applicability of the UNIFAC group contribution method and the UNIQUAC model. Both models fit the experimental data with similar low average root mean square deviations (rsmd ≤ 2.05%) yielding a satisfactory equilibrium prediction for the multicomponent system, although the predicted ethanol (rsmd ≤ 4.6%) compositions are not very good. The binary interaction parameters needed for the UNIQUAC model were obtained from the UNIFAC method.