Behavior of the Environmentally Compatible Absorbent 1-Butyl-3-methylimidazolium Tetrafluoroborate with 2,2,2-Trifluoroethanol: Experimental Densities at High Pressures and Modeling of PVT and Phase Equilibria Behavior with PC-SAFT EoS

A novel refrigerant absorbent system for absorption refrigeration based on ionic liquids as absorbents and a fluoroalcohol as the refrigerant is analyzed. New data of densities at several temperatures in the 283.15-333.15 K range and several pressures up to 40 MPa have been measured. Experimental data have been used to study the behavior and influence of the temperature, pressure, and composition on the isothermal compressibility and the isobaric thermal expansion coefficient. In addition, vapor pressures and saturated density data of the refrigerant 2,2,2-trifluoroethanol were used to determine PC-SAFT parameters, whereas for the absorbent 1-buty1-3-methylimidazolium tetrafluoroborate the molecular parameters were optimized using density data at atmospheric pressure. Using these calculated PC-SAFT parameters, PVT behavior, derived properties and vapor pressures were reasonably well predicted.