Phase equilibrium of CCS mixtures: Equation of state modeling and Monte Carlo simulation
Résumé
Carbon dioxide Capture and Storage (CCS) is considered as one possible option for reducing atmospheric emissions of C02 from human activities. During the processes of CCS, C02 is often accompanied by many gas impurities, such as N1, Ar, H2, CO, S02, 02 and NO. The presence of these gas impurities in the C02 gas Stream may affect the design of ces processes. Therefore, to understand the role played by these impurities, it is essential to know the thennodynamic properties of such gas mixtures under the conditions of C02 capture, transport and storage. Considering the variety of composition of these gas mixtures, it is necessary to have at one's disposai suitable models to predict their thermodynamic properties.
In this work, two thermodynam.ic models: the E-PPR78 and the PC-SAFT models, are applied for describing the phase equilibria properties of 77 binary ces mixtures containing C02, gas impurities (S02, 0 2 and NO), water and hydrocarbons. Our research results indicate that, bath models are able to accurately predict the phase behavior of binary CCS mixtures. It was however necessary to adjust the binary interaction parameters (k!J,PC-SAFT) within the PC-SAFT model to improve the prediction accuracy. Compared to the PC-SAFT model with one temperature-independent binary interaction parameter, the E-PPR78 model normally shows better prediction accuracy for the investigated systems. In addition, to extend the experimental database which was built for the evaluations of EoS modeling, the Monte Carlo (MC) simulation method is employed in this work to generate phase-equilibrium data of a few ces mixtures deemed as insufficiently described by experimental measurements reported in the open literature.