Modeling the phase behavior of cyclic compounds in mixtures of water, alcohols and hydrocarbons

The development of accurate models to predict the solvation, solubility, and partitioning of nonpolar and amphiphilic compounds in aqueous environments remains an important challenge. We develop state-of-the-art group-interaction models that deliver an accurate description of the thermodynamic properties of alkanes and alcohols in aqueous solution. The group-contribution formulation of the statistical associating fluid theory based on potentials with a variable Mie form (SAFT-γ Mie) is shown to provide accurate predictions of the phase equilibria, including liquid–liquid equilibria, solubility, free energies of solvation, and other infinite-dilution properties. The transferability of the model is further exemplified with predictions of octanol–water partitioning and solubility for a range of organic and pharmaceutically relevant compounds. Our SAFT-γ Mie platform is reliable for the prediction of challenging properties such as mutual solubilities of water and organic compounds which can span over 10 orders of magnitude, while remaining generic in its applicability to a wide range of compounds and thermodynamic conditions. Our work sheds light on contradictory findings related to alkane–water solubility data and the suitability of models that do not account explicitly for polarity.

Section: ■ Prediction Of Solvation Propertiesmentioning

confidence: 99%

Section: Prediction Of Solvation Propertiesmentioning

confidence: 99%

Predicting the Solvation of Organic Compounds in Aqueous Environments: From Alkanes and Alcohols to Pharmaceuticals

Hutacharoen

Dufal

Papaioannou

et al. 2017

“…In this work we review the modeling of the CO 2 + n -alkanes series phase behavior using the Group Contribution with Association Equation of State (GCA-EoS) . Previous works have shown the capacity of this model to accurately represent the complex multiphase behavior of mixtures containing hydrocarbons with polar and associating compounds, such as alcohols and water, − amines, , and furans . Moreover, this model also showed excellent predictive potential when applied to the phase behavior of multicomponent mixtures containing natural products − or fuel blends. − It is worth mentioning that the GCA-EoS is an extension to associating mixtures of the GC-EoS, originally proposed by Skjold-Jørgensen to model gas solubility.…”

Section: Thermodynamic Modelingmentioning

confidence: 99%

Multiphase Equilibria Modeling with GCA-EoS. Part I: Carbon Dioxide with the Homologous Series of Alkanes up to 36 Carbons

Prieto

Sánchez

Pereda

2015

The Group Contribution with Association Equation of State (GCA-EoS) has been successfully applied to represent the global phase behavior of carbon dioxide mixtures with alkanes. Using a single set of parameters, the model is able to predict vapor−liquid and liquid−liquid equilibria of binary mixtures not included in the parametrization procedure. Special emphasis was set on describing the transformation between types of fluid phase behavior to reduce the jeopardy of predicting incorrect liquid split. This family of binary systems has been investigated in previous works; however, this is the first time that GCA-EoS was shown to be able to represent the transformation between types of phase behavior as the length of the alkyl chain increases. The model was tested against an experimental database covering C 3 −C 36 alkanes, temperatures from 210 to 660 K, and pressures up to 400 bar. The wide range of conditions and the parametrization strategy are keys to develop a robust thermodynamic tool for predicting multiphase behavior.

“…When the packing fraction is assumed to be universal, g = constant, as applied by Mengarelli, GCA, , and Hao and Chen, Δ g = 0 and the equation becomes ln nobreak0em.25em⁡ γ k assoc = prefix∑ true.25ex site types i on k N i B ( ln true( X i X i ° true) − 1 − X i ° 2 ) + 1 2 ρ ρ k ° ∑ true.25ex site types i x host .25em i N i B ( 1 − X i ) …”

Section: Models In Current Engineering Practice and Association Theorymentioning

confidence: 99%

Wertheim’s Association Theory for Phase Equilibrium Modeling in Chemical Engineering Practice

Lira

Elliott

Gupta

et al. 2022

Association and complex formation are the most important contributors to nonidealities in modeling phase equilibria. Models based on Wertheim's association theory are reviewed in the context of current industrial practice, showing great promise in resolving many of the shortcomings of the currently available models. Several pitfalls of common models are highlighted, showing the advantages of association theory. Infinite dilution activity coefficients can provide valuable insights into the liquid phase nonidealities. Trends for various mixture classifications are tabulated and explained simply in terms of "differences in molecular association". The need for a systematic procedure to characterize association parameters is cited as the most important barrier to broader implementation of these models. Improper characterizations can undermine the advantages of association theory, possibly confusing whether it offers any advantage. Resolving these issues will improve traditional small molecule phase equilibrium modeling and many other applications as well.