Trends in solvent impact on infinite dilution activity coefficients of solutes reviewed and visualized using an algorithm to support selection of solvents for greener fluid separations

Abstract

• Infinite dilution activity coefficients (IDACs) were reviewed. • IDACs for a total of 268 solutes in 692 solvents were reviewed. • From the 77.173 IDACs reviewed, solvent effects were visualized. • Utilizing Van ‘t Hoff’s law in an algorithm, IDACs at varying T were compared. • Visualized trends for molecular solvents but also for ionic liquids. The infinite dilution activity coefficient, γ i ∞ , is a frequently used molecular descriptor to pre-select a solvent for various kinds of fluid separations. Unfortunately, information related to these coefficients is scattered through-out the open literature. Therefore, an open-source γ i ∞ -database containing 77.173 γ i ∞ data points over the temperature interval 243 K < T < 555.6 K for 268 solutes and 692 solvents is provided in the electronic supporting information of this work. Additionally, we performed an inter- and extrapolation data analysis algorithm using the Van ‘t Hoff equation to extend the γ i ∞ data points at 298.15 K. The γ i ∞ for five solutes (n-hexane, benzene, chloroform, acetone and ethanol) in a wide range of molecular solvents and ionic liquids (ILs) were compared. Various trends between the molecular solvent structure and the γ i ∞ are visualized, which allows for not only a pre-selection of solvents for targeted γ i ∞ but also visualizes the effect molecular modification of the solvent will have on the γ i ∞ . Overall, the presented methodology is complementary to approaches using simulation software, and helps acquiring a detailed understanding of the effect of the solvent structure on the γ i ∞ , which will facilitate solvent pre-selection in an early process design stage towards greener fluid separations.