Activity Coefficients at Infinite Dilution for Hydrocarbons in Fatty Alcohols Determined by Gas−Liquid Chromatography

Abstract

The selection of the most suitable selective solvent for separation processes such as extraction or extractive distillation plays an important role in the economical design. Since the largest deviation from ideality is observed at infinite dilution, limiting activity coefficients (γ∞) provide a useful tool for the optimal choice of the selective solvent. Therefore, activity coefficients at infinite dilution have been measured for 22 solutes (paraffins, olefins, chloroparaffins, aromatics, ketones, ethers, alcohols, and acetates) in fatty alcohols: octadecanol and eicosanol as a solvent. The measurements were carried out with the help of gas−liquid chromatography (GLC) at five and four temperatures, respectively. Furthermore, the observed temperature dependence of limiting activity coefficients is confirmed using excess enthalpy data. To determine the different interactions between the solutes and the solvents, the linear solvation energy relationship (LSER) or “Abraham method” is applied. To verify the ap...