Anhydrous ethanol is used in chemical, pharmaceutical and fuel industries.However, current processes for obtaining it involve high cost, high energy demand and use oftoxic and pollutant solvents. This problem occurs due to the formation of an azeotropicmixture of ethanol + water, which does not allow the complete separation by conventionalmethods such as simple distillation. As an alternative to currently used processes, this studyproposes the use of ionic liquids as solvents in extractive distillation. These are organic saltswhich are liquids at low temperatures (under 373,15 K). They exhibit characteristics such aslow volatility (almost zero/ low vapor ), thermal stability and low corrosiveness, which makethem interesting for applications such as catalysts and as entrainers. In this work,experimental data for the vapor pressure of pure ethanol and water in the pressure range of 20to 101 kPa were obtained as well as for vapor-liquid equilibrium (VLE) of the system ethanol+ water at atmospheric pressure; and equilibrium data of ethanol + water + 2-HDEAA (2-hydroxydiethanolamine acetate) at strategic points in the diagram. The device used for theseexperiments was the Fischer ebulliometer, together with density measurements to determinephase compositions. The experimental data were consistent with literature data and presentedthermodynamic consistency, thus the methodology was properly validated. The results werefavorable, with the increase of ethanol concentration in the vapor phase, but the increase wasnot shown to be pronounced. The predictive model COSMO-SAC (COnductor-like ScreeningMOdels Segment Activity Coefficient) proposed by Lin & Sandler (2002) was studied forcalculations to predict vapor-liquid equilibrium of systems ethanol + water + ionic liquids atatmospheric pressure. This is an alternative for predicting phase equilibrium, especially forsubstances of recent interest, such as ionic liquids. This is so because no experimental datanor any parameters of functional groups (as in the UNIFAC method) are needed
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