Vapor-liquid equilibrium of the (water + ethanol + glycerol) system: Experimental and modelling data at normal pressure

摘要

In this work, vapor-liquid equilibrium data of the ethanol-water-glycerol system were measured in an Othmer-type ebulliometer at normal pressure. The choice for this system was due to the importance of the ethanol-water separation. The samples analyses were done in a digital densimeter, and the methodology was previously validated with data available in the literature. Since the mean relative deviation was less than 5% in temperature and vapor composition, new data from mixtures of ethanol-water-glycerol were obtained. The experiments showed that glycerol is a promising solvent to ethanol dehydration since it eliminates the azeotrope and promotes the production of anhydrous ethanol. A thermodynamic model for this system was developed using the NRTL model to describe the non-ideality of the liquid phase. The modeling results were compared with experimental data and the deviations were lower than 7%. In this way, the model developed in this work can be used for simulation of ethanol dehydration.