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

• There is a lack in literature of experimental data of ethanol–water–glycerol system.
• Phase equilibrium knowledge is essential for the project of separation processes.
• The use of glycerol may suggest an important integrated biorrefinery concept.
• Ethanol–water azeotrope was broken even using glycerol/feed ratio.
• Low standard deviations were obtained in ethanol–water–glycerol system VLE data.

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.