title: Solubility of CO2 in [1-n-butylthiolanium][Tf2N]+toluene mixtures: liquid-liquid phase split separation and modelling.
abstract: Carbon dioxide has been shown to be an effective antisolvent gas for separating organic compounds from ionic liquids (ILs) by inducing a liquid-vapour to liquid-liquid-vapour transition. Using carbon dioxide, toluene can be separated from imidazolium, phosphonium and pyridinum cation-based ILs with the bis(trifluoromethylsulfonyl)imide anion, which is relatively hydrophobic and has a high toluene solubility. A new IL with relatively low viscosity is tested here for the same toluene separation process: 1-n-butylthiolanium bis(trifluoromethylsulfonyl)imide. Carbon dioxide solubility in binary and ternary systems containing toluene and 1-n-butylthiolanium bis(trifluoromethylsulfonyl)imide is measured at 298.15 and 313.15 K up to 7.4 MPa. Solubility behaviour in this IL is similar to imidazolium-based ILs with the same anion. However, phase split pressures are lower when 1-n-butylthiolanium bis (trifluoromethylsulfonyl)imide is used instead of 1- n-hexyl-3-methylimidazolium bis(trifluoromethylsu- lfonyl)imide at the same conditions of temperature and initial composition of toluene in the IL. Solubility data are modelled with the conductor-like screening model for real solvents combined with the Soave-Redlich-Kwong equation of state, which provides good qualitative results.
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN 46556, USA.
authors.forename: Roberto I
authors.initials: RI
authors.lastname: Canales
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN 46556, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Lubben
authors.affiliation: School of Chemical Engineering and Analytical Science, University of Manchester, Manchester M13 9PL, UK.
authors.forename: Maria
authors.initials: M
authors.lastname: Gonzalez-Miquel
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN 46556, USA jfb@nd.edu.
authors.forename: Joan F
authors.initials: JF
authors.lastname: Brennecke
keywords: CO2 solubility; conductor-like screening model for real solvents; ionic liquids