Separation of species from ionic liquids

The tremendous interest in the use of ionic liquids as environmentally benign solvents for reactions presents the need to develop equally environmentally friendly methods to separate target solutes from mixtures containing ionic liquids. Here we discuss various separation methods and present results for phase behavior and physical properties important for separations. In particular, we show that liquid/liquid extraction with water will inevitably result in the loss of some ionic liquid solvent and that a variety of solutes can be extracted from ionic liquids with supercritical CO2 without cross-contamination. In addition, we show that pure ionic liquids are very incompressible and do not show any evidence of shear thinning.