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. (C) 2002 Elsevier Science B.V. All rights reserved.