Density Modeling of High-Pressure Mixtures using Cubic and Non-Cubic EoS and an Excess Volume Method

A central issue in the equation of state (EoS) development is to describe accurately fluid density and thus other thermodynamic properties based on it. This study attempts investigate modeling high-pressure mixtures, particularly related reservoir fluids, by cubic non-cubic EoS. large database binary mixtures petroleum fluids was established used compare some typical EoS, including SRK, PR, PC-SAFT, Soave-BWR, GERG-2008. For first four their volume translated versions were also evaluated. The evaluation results suggest that EoS form three groups order accuracy: GERG-2008 as group, Soave-BWR PC-SAFT second, PR SRK last. Volume translation more effective for last group but it does not change order. model-to-model comparison made between 500 pairs over a wide range conditions, showing differences excess are usually small different models. observation motivated introduction an method, which combines two estimating final properties. this method using shows can deliver reasonable estimates simple model like SRK. Its limitations analyzed its potential application densities discussed.