Modelling the phase behavior of alkane mixtures in wide ranges of conditions: New parameterization and predictive correlations of binary interactions for the RKPR EOS

Abstract

After showing in a previous publication a clear superiority to the classic Peng-Robinson EoS for the description of high pressure phase behavior in the more asymmetric alkane-alkane binary mixtures, in this work the RKPR EoS is turned into a predictive model by developing correlations of interaction parameters for all possible pairs or normal alkanes, associated also to a new parameterization of pure compounds. The proposed correlations are based on van der Waals quadratic mixing rules. Repulsive interaction lij parameters are implemented in all cases, while attractive kij interactions were necessary only for the methane-series and the more asymmetric systems of propane, in particular with carbon numbers higher than 24. The analysis of the results, in comparison to an important diversity of data available for several dozens of systems, demonstrates a very good predictive power for the new correlations, which could be useful in modeling the phase behavior of different hydrocarbon fluids.