A new formulation of the predictive NRTL-PR model in terms of k(ij) ă mixing rules. Extension of the group contributions for the modeling of ă hydrocarbons in the presence of associating compounds

International audienceA generalized NRTL model was previously proposed for the modeling of non ă ideal systems and was extended to the prediction of phase equilibria ă under pressure according to the cubic NRTL-PR EoS. In this work, the ă model is reformulated with a predictive k(ij) temperature and ă composition dependent mixing rule and new interaction parameters are ă proposed between permanent gases, ethane and nitrogen with hydrocarbons, ă ethane with water and ethylene glycol. Results obtained for excess ă enthalpies, liquid-vapor and liquid-liquid equilibria are compared with ă those provided by the literature models, such as VTPR, PPR78, CPA and ă SRKm. A wide variety of mixtures formed by very asymmetric compounds, ă such as hydrocarbons, water and ethylene glycols are considered and ă special attention is paid to the evolution of k(ij) with respect to mole ă fractions and temperature. (C) 2010 Elsevier B.V. All rights reserved