Blanca Estela García-Flores

Phase Behavior Prediction and Modeling of LNG Systems with EoSs - What is Easy and What is Difficult?

Blanca E. Garcia-Flores1, Daimler N. Justo-Garcia2, Roumiana P. Stateva3 and Fernando Garcia-Sanchez1 1Laboratory of Thermodynamics, Research Program in Molecular Engineering, Mexican Petroleum Institute, Mexico, D.F., 2Department of Chemical and Petroleum Engineering, ESIQIE, National Polytechnic Institute, Mexico, D.F., 3Institute of Chemical Engineering, Bulgarian Academy of Sciences, Sofia, 1,2Mexico, 3Bulgaria

Prediction of Phase Behavior for the System Methane-Carbon Dioxide- Hydrogen Sulfide-Water with the PR and PC-SAFT Equations of State

In this work, we present the predicted multiphase behavior (vapor-liquid, liquid-liquid, and vapor-liquid-liquid equilibria) for a quaternary mixture containing methane, carbon dioxide, hydrogen sulfide, and water. The capabilities of the PR (Peng-Robinson) and PC-SAFT (Perturbed-Chain Statistical Associating Fluid Theory) equations of state (EoS) to predict the phase behavior exhibited by this mixture were compared and analyzed. The computer algorithm used for isothermal multiphase flash calculations is based on the minimization of the Gibbs energy along with stability analysis to find the most stable state of the system. The binary interaction parameters used with the PR EoS for modeling this system were taken from the literature whereas the interaction parameters for the PC-SAFT were obtained from the regression of binary vapor-liquid equilibrium data. The results obtained differ from each other and demonstrate different capabilities and accuracies of the present thermodynamic models in the predictions.