Molecular Modeling ofFluoropropene Refrigerants.

Different fluoropropenes are currently considered asrefrigerants,either as pure compounds or as components in low GWP (global warmingpotential) refrigerant mixtures. Due to their limited commercial production,experimental data for the thermophysical properties of fluoropropenesand their mixtures are in general rare, which hampers the explorationof their performance in technical applications. In principle, molecularsimulation can be used to predict the relevant properties of refrigerantsand refrigerant blends, provided that adequate intermolecular potentialfunctions (“force fields”) are available. In our earlierwork (Raabe, G.; Maginn, E. J., J. Phys. Chem. B2010, 114, 10133–10142), we introduceda transferable force field for fluoropropenes comprising the compounds3,3,3-trifluoro-1-propene (HFO-1243zf), 2,3,3,3-tetrafluoro-1-propene(HFO-1234yf), and hexafluoro-1-propene (HFO-1216). In this paper,we provide an extension of the force field model to the trans- andcis-1,3,3,3-tetrafluoro-1-propene (HFO-1234ze(E), HFO-1234ze) andthe cis-1,2,3,3,3-pentafluoro-1-propene (HFO-1225ye(Z)) as well asrevised simulation results for HFO-1216. We present Gibbs ensemblesimulation results on the vapor pressures, saturated densities, andheats of vaporization of these compounds in comparison with experimentalresults. The simulation results show that the force field model enablesreliable predictions of the properties of the different fluoropropenesand also reproduces well the differing vapor–liquid coexistenceand vapor pressure curve of the cis- and trans-isomers of 1,3,3,3-tetrafluoro-1-propene,HFO-1234ze and HFO-1234ze(E). For these two isomers, we also presentmolecular dynamics simulation studies on their local structure. [ABSTRACT FROM AUTHOR]