Group Contribution Method for Viscosities Based on Entropy Scaling Using the Perturbed-Chain Polar Statistical Associating Fluid Theory

Abstract

In this work we propose a new predictive entropy-scaling approach for Newtonian shear viscosities based on group contributions. The approach is based on Rosenfeld's original work [Y. Rosenfeld, Phys. Rev. A 1977, 15, 2545 -2549. The entropy scaling is formulated as third order polynomial in terms of the residual entropy as calculated from a group-contribution perturbed chain polar statistical associating fluid theory (PCP-SAFT) equation of state. In this study we analyze the course of entropy scaling parameters within homologous series and suggest suitable mixing rules for the parameters of functional groups. The viscosity of non-polar, of polar, and of selfassociating (hydrogen bonding) components are considered. In total 22 functional groups are parametrized to viscosity data of 110 pure substances, from 12 different chemical families. The mean absolute relative deviations (MADs) to experimental

Probing the link between residual entropy and viscosity of molecular fluids and model potentials

“…Other authors [24,25,26,27,28,54,29,30] have proposed alternative residual-entropy-based schemes that are more successful at scaling the viscosity in the dilute gas limit, but they introduce significant deviations from monovariate scaling in the compressed liquid phase for small non-associating molecules and in the gaseous phase for associating molecules. For that reason the alternative entropy scalings are not discussed in this work; further work will investigate potential means of reconciling these different scaling approaches.…”

Integrating superstructure‐based design of molecules, processes, and flowsheets

“…The calculation of the transport properties κ from PC‐SAFT has been proposed by Lötgering‐Lin and Gross for viscosities η and by Hopp and Gross for thermal‐conductivities λ . The models are based on Rosenfeld's entropy scaling, who proposed that transport properties are an univariate function of the residual entropy s res .…”

“…The calculation of the transport properties κ from PC-SAFT has been proposed by Lötgering-Lin and Gross 58 Gross has also developed models for the prediction of self-diffusion coefficients based on entropy scaling and PC-SAFT, 72 which could thus also be easily implemented into the presented 1-stage CoMT-CAMD method.…”

1-stage CoMT-CAMD: An approach for integrated design of ORC process and working fluid using PC-SAFT

“…Since an equilibrium fluid model is currently employed, any objective function based on equilibrium properties can be considered (e.g., net power output, thermal or exergy efficiency). Recently, PC-SAFT has been extended to calculate transport properties [37,38] of the NLP solution is lower than the lower bound (for details on outer approximation see Floudas [42]). We use the software GAMS (version 24.6.1) [43] and the deterministic MINLP solver DICOPT [44] with the subsolvers SNOPT [45] and BARON [46] to solve the NLPs and MIPs, respectively.…”