Group Contribution Method for Predicting the Phase Behavior of Binary Mixtures Containing Carbon Dioxide

This work deals with estimation of temperature dependent binary interaction parameters (kij) for binary systems containing CO2 using the Soave-Redlich-Kwong equation of state with a group contribution method. In this paper six groups, namely CH3, CH2, CH, CH4 (methane), C2H6 (ethane), and CO2 (carbon dioxide) are defined and their relevant values of group interaction parameters are optimized. Using this method, it is possible to estimate the kij of any mixture containing carbon dioxide and hydrocarbons at any temperature along the coexistence curve. The results obtained in this study are, in most cases, accurate.