Vapor-liquid equilibrium in low pressure water+congener mixtures

Abstract

Vapor-liquid equilibrium in binary water+congeners mixtures found in alcoholic distillation has been analyzed using the Peng-Robinson equation of state and one of the most popular modern mixing rules, the Wong-Sandler model. Accurate modeling of the concentration of congeners (substances different from ethanol and water) in the vapor phase is of special importance because these substances give some special characteristics of flavor and aroma to the final distilled spirit and also because their concentrations are regulated by law. In the Wong-Sandler mixing rules the van Laar model for the Gibbs excess energy has been used. The type of model used in this work is commonly used to correlate high pressure phase equilibrium and has not yet been used to treat complex low pressure water+congener mixtures as done in this work. Eight binary water+congeners mixtures have been considered for analysis. Comparison with available literature data is done and the accuracy of the model to correlate the pressure and the vapor phase concentration of the congeners is discussed. It is concluded that the model used is accurate enough for distillation analysis, modeling and simulation.

Experimental determination and calculation of the critical curves for the binary systems of CO2 containing ketone, alkane, ester and alcohol, respectively

“…These systems are best suited for the extraction of thermosensitive biomaterials and medicines. From Gibbs phase rule, a binary mixture has a gas-liquid critical curves in the three-dimensional pressure-temperature-composition (p, T, x) space [3]. Our laboratory has constructed a changeable-volume-autoclave consisting of a cylindrical steel vessel for investigating high-pressure phase equilibria and critical curves.…”

Isobaric Vapor Liquid Equilibrium (VLE) Data of the Systems Ethylene Glycol-Glycerol and 1,2-Propylene Glycol-Ethylene Glycol at 20Pa

“…Vapor liquid equilibrium (VLE) data [1][2][3][4] are the basis of process improvement and simulation. Till now there is no research on VLE data at medium pressure, this work is necessary for distillation technology development and project improvement.…”