Statistical Associating Fluid Theory. 1. Application toward Describing Isoparaffins

Abstract

We apply recent advances in perturbation theory-based equation of state models to correlate thermodynamic property data for pure compounds. Parameters for the equation of state were regressed for over 240 compounds, including a number of homologous series and branched paraffins. We find that the equation of state is capable of quantitatively correlating all of the pure-component experimental data we tested. Our primary interest, however, is to look for trends in the parameters of the equation of state in order to extrapolate to properties of other types of molecules. For isoparaffins, increased branching for a given carbon number leads to a SAFT model molecule with fewer segments but with larger segment volume and energy parameters. These trends correlate highly with topological descriptors characterizing the degree of branching, suggesting a route toward estimating parameters for molecules for which data are in short supply or do not exist.