High-pressure phase behavior of systems with ionic liquids: measurements and modeling of the binary system fluoroform+1-ethyl-3-methylimidazolium hexafluorophosphate

In order to gain insight into the phase behavior of ionic liquids+supercritical fluids, the phase boundaries of a binary mixture of an air- and water-stable ionic liquid and a supercritical fluid has been studied experimentally. For this purpose, fluoroform (CHF3) was considered as the supercritical fluid and 1-ethyl-3-methylimidazolium hexafluorophosphate ([emim][PF6]) was selected as the ionic liquid. A synthetic method was used to measure vapor–liquid and solid–liquid boundaries. Results are reported for CHF3 concentrations ranging from 10.1 to 99.0 mol%, and within temperature and pressure ranges of 309.3–367.5 K and 1.6–51.6 MPa, respectively. The Peng–Robinson equation of state is used to model this binary system.