A fresh look at the thermodynamic consistency of vapour-liquid equilibria data

A Practical Fitting Method Involving a Trade-Off Decision in the Parametrization Procedure of a Thermodynamic Model and Its Repercussion on Distillation Processes

“…The proposed methodology is applied to two significant binary systems in the dissolution thermodynamic field, such as acetone-ethanol and benzene-hexane. The data checking is carried out with different classical methods, which is recommended in the recent literature [6]. In addition, a rigorous method recently designed by the authors [7] was also used in order to guarantee the quality of the experimental data used.…”

“…The Kojima test rejects five data series, with the error observed in the system n°12 being critical. A new methodology recently proposed by us [6,7] was also applied, which rejects nine systems: three by the integral form (n°9, 11,12) and six by the differential form (n°1, 3, 4, 8, 9, 12). These systems present obvious signs of inconsistency that are also observed by at least one of the other methods.…”

“…Two systems, considered as standard in many studies on thermodynamic behavior of solutions, are selected since the necessary experimental information (VLE and h E )is available in literature. After checking the data sets [6,7], making up the testing $ modeling steps, and having obtained the corresponding result fronts, each candidate model is analyzed on its suitability for process simulation.…”

Azeotropy: A Limiting Factor in Separation Operations in Chemical Engineering - Analysis, Experimental Techniques, Modeling and Simulation on Binary Solutions of Ester-Alkane

“…For many years, our research group has conducted experiments on azeotropic systems (see [9][10][11][12]), mainly on solutions containing esters, alkanols and alkanes. Experimental developments have also been proposed to determine vapor-liquid equilibria (VLE) [13,14], and theoretical approaches to m o d e le x p e r i m e n t a lt h e r m o d y n a m i cd a t a [ 1 4 -17] and to assess their quality [18,19]. In this chapter, the azeotropy is studied from different perspectives which governs the design of some Laboratory Unit Operations and Experimental Methods in Chemical Engineering engineering operations, and more specifically those cited above (E-M-S), actions that the authors have pursued in recent works [20,21].…”

“…Initially, the phenomenon of azeotropy is considered, supported by the basic thermodynamic formulation, in an attempt to understand its origin and sensitivity to changes in the system conditions. The experimental methods available to measure azeotropic points are exposed, their strengths and limitations are discussed, and reference is made to tools [18,19] to determine data quality. Regarding the modeling, different strategies are used to characterize VLE diagrams and to estimate the presence of azeotropes, with a critical analysis to predict the appearance of singular points.…”