화학공학소재연구정보센터
Journal of Chemical and Engineering Data, Vol.65, No.12, 5920-5932, 2020
Parameterization of SAFT Models: Analysis of Different Parameter Estimation Strategies and Application to the Development of a Comprehensive Database of PC-SAFT Molecular Parameters
Parameterization is defined as the method used to assign values to component-dependent parameters of an Equation of State (EoS). For SAFT-type EoS, historically, little attention has been paid to these methods, while higher importance was devoted to the theoretical foundations of the model. In this study, our ultimate objective was defined as the accurate reproduction of VLE and energetic properties (vapor pressure P-sat, saturated-liquid density rho(sat)(liq), enthalpy of vaporization Delta H-vap, saturated-liquid heat-capacity c(P, liq)(sat)). Obviously, fitting the EoS parameters to these four property data immediately ensures meeting our objective. However, noticing that these four property data are not always available in practice and that some property data may have a marginal impact on the results of the fitting procedure, we searched for the necessary and sufficient properties against which EoS parameters should be regressed to meet our objective. Twelve combinations of property data among P-sat, rho(sat)(liq), Delta H-vap, and c(P,liq)(sat) were tested. For each property combination, the three PC-SAFT molecular parameters (m, sigma, epsilon/k) were estimated for 544 nonassociating species disposing of experimental data for the four target properties. We concluded that it is necessary and sufficient to fit the PC-SAFT parameters to both P-sat and rho(sat)(liq) data. Finally, a molecular-parameter database for the PC-SAFT EoS was proposed for 1252 nonassociating compounds disposing of at least P-sat and rho(sat )(liq)data. The performance of these predictions is contrasted against other SAFT (I-PC-SAFT) and cubic EoS (tc-PR and gen-tc-PR).