Thermodynamics Research Center / ThermoML | Fluid Phase Equilibria

ABSTRACT

Experimental activity coefficients of different alcohols (methanol, ethanol, 1-propanol, 2-propanol, 1- butanol, 2-butanol and 1-pentanol) and ketones (acetone, 2-butanone, 2-pentanone, 3-methyl-2- butanone and 4-methyl-2-pentanone) at infinite dilution in 1-Ethyl 3-Methylpyridinium Ethyl Sulfate ionic liquid ([EMpy][ESO4]) were measured at temperatures from 323 K to 373 K, using the inverse gas chromatography technique. The experimental results show that infinite dilution activity coefficients of both alcohols and ketones only marginally depend on temperature between 323 K and 373 K. Further, it could be observed that infinite dilution activity coefficients of methanol, ethanol, and 1-propanol are lower than unity, whereas 1-butanol and 1-pentanol activity coefficients at infinite dilution were higher than unity. In contrast, the activity coefficients at infinite dilution of all ketones were found to be greater than unity. Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT) was used to model the obtained experimental data. Firstly, the pure-component parameters for [EMpy][ESO4] were determined by fitting experimental pure-IL densities and activity coefficients of 1-propanol. Based on this, activity coefficients in binary [EMpy][ESO4]/alcohol and [EMpy][ESO4]/ketone mixtures were modeled with good agreement to experimental data. Binary interaction parameters between [EMpy][ESO4]/alcohol and [EMpy][ESO4]/ ketone were used. They were found to depend logarithmically on the chain length of any alcohol or ketone, respectively.