Phase behaviour of the systems containing ionic liquids and/or supercritical carbon dioxide

Advanced solvents such as ionic liquids (ILs) and supercritical carbon dioxide (ScCO2) have been viewed as a class of environmentally friendly, green solvents, with potential widespread applications. Owning to their characteristics, they have potential to replace toxic solvents in chemical reaction and separation processes. As ionic liquids are made up of at least two components which can be varied (the anion and cation), the solvents can be designed with a particular solvent power. On the other hand, due to the high compressibility of supercritical carbon dioxide, their physicochemical properties can be adjusted by varying pressure. Therefore, ILs and ScCO2 as well as their combinations can be considered as designer solvents.
In order to design and develop clean processes, knowledge on phase behaviour of the systems containing ionic liquids and/or supercritical carbon dioxide is essential. In this contribution, phase behaviour of various systems such as terpenes/CO2/hydrogen, vegetable oil / ILs / methanol and vegetable oils / ILs /free fatty acids containing these advanced solvents were studied. These data were used to interpret the kinetics of reaction systems or to evaluate the possibility of separation.