Standardized Critical Point-Based Numerical Solution of Statistical Association Fluid Theory Parameters: The Perturbed Chain-Statistical Association Fluid Theory Equation of State Revisited

Abstract

The current study has aimed at developing an approach replacing the lists of the compound-specific molecular parameters attached to perturbed chain-statistical association fluid theory (PC-SAFT) by the entirely transparent and universal method for their derivation. The proposed approach requires limited data for the numerical solution of the PC-SAFT parameters, namely, the critical constants and the triple point liquid density. Its implementation has necessitated a careful re-evaluation of part of the PC-SAFT universal parameters matrix and some additional revisions. The resulting model appears to be virtually free of several undesired numerical pitfalls characteristic for PC-SAFT. The proposed equation of state (EoS) has been implemented for modeling data of nonpolar substances such as the light compounds, n-alkanes, and 1-alkenes and their mixtures. Using a large experimental database (more than 6000 points) it has been demonstrated that it exhibits remarkable precision in predicting the high-pressure liquid phase densities and sound velocities, with AAD hardly exceeding 3% even in the cases of complex asymmetric mixtures. However, a major drawback of the proposed model is a poor accuracy of predicting the vacuum vapor pressures of heavy compounds away from their critical points.

High-pressure phase equilibrium in the {carbon dioxide (1) + 1-chloropropane (2)} binary system

“…The detailed explanations of the models considered in this study are available in the literature [28][29][30][31][32][33] and here we provide only their brief overviews.…”

“…As an alternative, it has been recently proposed [30][31][32] to apply PC-SAFT analogously to cubic EoS models, namely by solving Tables 3 lists pertinent input pure component data for CO 2 and 1-chloroproapane as taken over from the DIPPR database [39] and Table 4 lists the calculated values of pure compound parameters for both the SBWR and CP-PC-SAFT EoS models.…”

“…Following the principle noted for the choice of models, in the current study we then aim at comparing four predictive approaches representing four different types of models of various degrees of complexity, namely the PR EoS [28], the SBWR EoS [29], the CP-PC-SAFT EoS [30][31][32], and the COSMO-RS model [33].…”

Integrating support vector regression with genetic algorithm for CO2-oil minimum miscibility pressure (MMP) in pure and impure CO2 streams

“…SAFT-type EoS is acknowledged to be accurate for predicting the phase behavior of CO 2 -containing systems [38]. Although standardized parameterization was developed for such EoS [39,40], they were few used in the oil and gas industries [41] and especially to calculate MMPs because they lack accuracy to predict mixture critical points. Moreover, as explained by several authors, they may suffer from numerical problems [42][43][44].…”

Can DIPPR Database be Used for an Estimation of the Speed of Sound? A Case Study of Liquid Hydrocarbons

“…During the last years, some improvements in the prediction of the saturated speed of sound were reached by the hybridising cubic EoS and SAFT approaches (Polishuk, 2011) or via the usage of the critical data and the density at the triple point, so called CP-PC-SAFT model (Polishuk, 2014). Thus, the basic required parameters of these models can be obtained from the DIPPR reference data only.…”