화학공학소재연구정보센터
Industrial & Engineering Chemistry Research, Vol.59, No.29, 13290-13304, 2020
Combined Experimental and Theoretical Studies on the Prediction of the Isobaric Vapor-Liquid Association Phenomena for Binary and Ternary Mixtures of Water, Ethanoic Acid, and Propanoic Acid
It is a considerable challenge for the phase behavior of chemical separation industry to correlate and predict the vapor-liquid equilibria (VLE) data of the binary and ternary systems containing associating components because it is not known how these forms exist in the experimental condition, such as homogeneous or heterogeneous dimers or trimers, even polymers, and so on. Herein, VLE data for the associating ternary system, water + ethanoic acid + propanoic acid, and the three-constituent binary systems have been measured by different liquid-phase compositions using a Fischer ebulliometer at 101.33 kPa. The structures and distribution of various clusters in water, ethanoic acid, and propanoic acid systems were fully optimized at the B3LYP/6-31+G(d) level of theory using Gaussian 09. Then, we developed a strategy that could calculate the liquid activity coefficients by considering the distribution of the associating components in the strong association systems. This method is called the discrete clusters (DC) model, and, for comparison, Wilson, NRTL, and UNIQUAC models were employed to correlate the VLE data for the three-constituent binary systems. Also, the VLE data of the ternary system were estimated from the DC, Wilson, NRTL, and UNIQUAC models without any additional adjustment. Our DC model, which considered the explicit number of various clusters, showed better agreement and a smaller deviation from the experimental data. These VLE data derived from the DC model can be used for the design and simulation of the distillation behavior of the binary and ternary association systems.