High-Pressure Phase Equilibria in an Ethanol/Water Binary System: Experimental Data and Modeling

Abstract

Experimental data of vapor–liquid equilibria (VLE) are reported for the binary systems: ethanol (1) + water (2) at 100, 1500, and 2000 kPa. The data were verified for thermodynamic consistency by using different low- and high-pressure tests. The following minimum azeotropes were found for the binary systems: x1,az = y1,az = 0.899 and T = 351.39 K at 100 kPa, x1,az = y1,az = 0.857 and T = 440.70 K at 1500 kPa, and x1,az = y1,az = 0.850 and T = 453.83 K at 2000 kPa. The quality of the azeotropic data obtained was established by considering the trend of the bibliographic azeotropic data. The phase behavior was modeled using the Peng–Robinson equation of state (EOS) with several mixing rules and the perturbed-chain statistical associating fluid theory. The experimental data were satisfactorily correlated and a qualitative agreement with these predictive models was observed.