The viability of an azeotropic distillation process using 2,2,4-trimethylpentane (isooctane) as an entrainer to dehydrate ethanol and obtain a mixture of ethanol + isooctane without water is analyzed utilizing both an experimental procedure and an equilibrium-model-based simulation. The direct manufacture of this mixture of ethanol + isooctane for use as gasoline should avoid the additional cost of dehydrating ethanol in an earlier process. Experimental results indicate that azeotropic distillation allows obtaining mixtures of isooctane + ethanol with water concentrations lower than 50 ppm. The results indicate that the most critical parameter for this process is the reboiler heat duty. Low values of this parameter (<2.2 kJ/g of feed ethanol) produce mixtures of ethanol + isooctane with excessive water contents. At high heat duty values (>3.6 kJ/g of feed ethanol) the azeotropic distillation column does not function properly, as the top stream condenses giving only one liquid phase. Results of the equilibrium-model-based simulation of the process yield results having a similar trend to the experimental ones. However, significant discrepancies are observed in some values, which could be attributed to the calculation of the liquid-liquid equilibrium. It is therefore necessary to improve the correlation of experimental equilibrium data of determined regions on the ternary system diagram.

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