Simultaneous Predictions of Chemical and Phase Equilibria in Systems with an Esterification Reaction Using PC-SAFT

Abstract

The study of chemical reactions in multiple liquid phase systems is becoming more and more relevant in industry and academia. The ability to predict combined chemical and phase equilibria is interesting from a scientific point of view but is also crucial to design innovative separation processes. In this work, an algorithm to perform the combined chemical and liquid–liquid phase equilibrium calculation was implemented in the PC-SAFT framework in order to predict the thermodynamic equilibrium behavior of two multicomponent esterification systems. Esterification reactions involve hydrophobic reacting agents and water, which might cause liquid–liquid phase separation along the reaction coordinate, especially if long-chain alcoholic reactants are used. As test systems, the two quaternary esterification systems starting from the reactants acetic acid + 1-pentanol and from the reactants acetic acid + 1-hexanol were chosen. It is known that both quaternary systems exhibit composition regions of overlapped chemical and liquid–liquid equilibrium. To the best of our knowledge, this is the first time that PC-SAFT was used to calculate simultaneous chemical and liquid–liquid equilibria. All the binary subsystems were studied prior to evaluating the predictive capability of PC-SAFT toward the simultaneous chemical equilibria and phase equilibria. Overall, PC-SAFT proved its excellent capabilities toward predicting chemical equilibrium composition in the homogeneous composition range of the investigated systems as well as liquid–liquid phase behavior. This study highlights the potential of a physical sound model to perform thermodynamic-based modeling of chemical reacting systems undergoing liquid–liquid phase separation.

Fitting Error vs Parameter Performance─How to Choose Reliable PC-SAFT Pure-Component Parameters by Physics-Informed Machine Learning

“…The possible contributions (hard-chain repulsion, dispersion interaction, association, ionic interaction) calculate for the total residual Helmholtz energy by summation. Detailed information about applications can be found in the literature for, e.g., polymer systems, ,, pharmaceuticals, , ionic liquids, ,, solubility modeling, , or reaction modeling. , …”

Chemical Equilibrium in the System Acetic acid–n-Amyl Alcohol–n-Amyl Acetate–Water at 323.15 K and Atmospheric Pressure: Experimental Data and Equilibrium Constant Estimation

“…These data were obtained in our previous work, 19 during which we encountered certain difficulties in capturing the heterogeneous chemical equilibrium state for the region of the low values of the α 2 : the chemical equilibrium was established extremely slowly, the continuous "drift" of the composition was observed which was caused, in particular, by the simultaneous phase transition "inhibiting" the reaction. Consequently, the application of the α-variables and PC-SAFT calculation 20 might be useful for the additional correlation of the simultaneous chemical and phase equilibria data.…”

“…This can be done through an experimental investigation of vapor–liquid equilibria, , using several modeling approaches, e.g. UNIFAC, UNIQUAC, NRTL, SAFT, − and with quantum chemical calculations . In particular, recently, Ascani et al have studied the ability of PC-SAFT to predict simultaneously chemical and phase equilibria in systems with an esterification reaction including the system under consideration in our work.…”

“…19 The obtained data were compared with the ones at 318.15. 19,20 For the estimation of the chemical equilibrium constant, three different approaches were applied: an empirical equation, the UNIFAC model, and quantum chemical calculations.…”

Thermodynamic Properties of Binary Mixtures Containing Ionic Liquid 1-Butyl-3-methylimidazolium Thiocyanate and Ethanolamines at Different Temperatures: Measurement and PC-SAFT Modeling

“…Chemical engineering requires precise thermodynamic data and calculations for different purposes such as process design, and it means using the equation of state as one of the most important tools in thermodynamic would be necessary for calculations and modeling. − Accordingly, selecting the proper equation of state is crucial for chemical engineering purposes between the numerous models. − On the other hand, statistical mechanics includes equation of states that uses microscopic information from quantum mechanics of a certain system, processes it, and calculates macroscopic measurable variables. − One of the most successful equations of states is Perturbation chain- statistical associated fluid theory (PC-SAFT) that has been applied for modeling of the mixture’s thermodynamic properties. − A molecule is assumed as a hard chain consisting of hard spheres in PC-SAFT by imposing first- and second-order thermodynamic perturbations. , Also, different terms have been added to extend the model for different varieties of the molecules. − …”