Gamma infinity data for the separation of water-butan-1-ol mixtures using ionic liquids

Abstract

Bio-butanol is produced from biomass by fermentation and must be separated from the aqueous phase. Ionic liquids (ILs) are a novel attractive solvents, which can be used for removing butan-1-ol from the aqueous fermentation broth. The thermal properties, obtained with DSC and the densities of IL octyltriethylammonium bis{(trifluomethyl)sulfonyl}imide, [N8,2,2,2][NTf2] as a function of temperature have been measured over a temperature range (289.15–385.15) K. The activity coefficients at infinite dilution, γ13∞, for 63 solutes, including alkanes, cycloalkanes, alkenes, alkynes, aromatic hydrocarbons, alcohols, water, thiophene, tetrahydrofuran, ethers, and ketones in the [N8,2,2,2][NTf2] were determined by gas–liquid chromatography at six temperatures from 318.15 K to 368.15 K. The gas–liquid partition coefficients, KL were calculated for all solutes. The partial molar excess Gibbs energies ΔG1E,∞, enthalpies ΔH1E,∞, and entropies ΔS1E,∞ at infinite dilution were calculated from the experimental γ13∞ values obtained over the temperature range. The selectivity and capacity for water/butan-1-ol separation problem were calculated from γ13∞ data and were compared to literature values for bis{(trifluomethyl)sulfonyl}imide-based ILs with different cations, and with all available data for ILs.