Key points are not available for this paper at this time.
Hydrofluorocarbon refrigerants are being phased out over the next two decades due to concerns about high global warming potential. In order to separate refrigerant mixtures that form azeotropes, new technologies will be required. Currently, fractional distillation is unable to efficiently separate azeotropic refrigerant mixtures. Extractive distillation using an ionic liquid as the entrainer offers a solution. Vapor–liquid equilibria data for refrigerants difluoromethane (HFC-32), pentafluoroethane (HFC-125), 1,1,1,2-tetrafluoroethane (HFC-134a), 1,1,1-trifluoroethane (HFC-143a), chlorodifluoromethane (HCFC-22), propane (HC-290), and isobutane (HC-600a) and ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate (C4C1imPF6) was regressed using the Peng–Robinson equation of state with the van der Waals 1-parameter mixing rule and Boston–Mathias nonideal correction. Process flow diagrams using ASPEN simulations were prepared for demonstrating how multicomponent mixtures of these refrigerants can be separated. Opportunities for measuring and modeling the solubility of new refrigerants in ionic liquids are discussed, and challenges remain for effectively separating some azeotropic refrigerant mixtures containing hydrofluorocarbons and hydrocarbons.
Finberg et al. (Tue,) studied this question.