Fluid-phase-equilibrium prediction of fluorocompound-containing binary systems with the predictive E -PPR78 model

Abstract

In order to reduce the overall emissions of greenhouse gases and to be in compliance with the current environmental regulations, a new class of refrigerants, making use of fluorocompounds has appeared. Such refrigerants are often blends of alkanes, CO 2 and fluorocompounds. Consequently an equation of state (EoS) able to predict the properties of both pure compounds and multi-component systems is required to design processes involving fluorocompounds or to implement a product-design approach aimed at identifying new refrigerant mixtures. It is however well-acknowledged that the phase behavior of binary systems like, e.g., an alkane and its corresponding perfluoroalkane, show significant deviations from ideality that need to be accurately accounted for by a thermodynamic model. In this study, in order to get a predictive model applicable to fluorocompound-containing binary systems, six groups were added to the Enhanced-PPR78 model which combines the Peng-Robinson EoS and a group contribution method aimed at estimating the binary interaction parameters, () ij kT, involved in Van der Waals one-fluid mixing rules.

Thermodynamic properties of hydrofluoroolefin (R1234yf and R1234ze(E)) refrigerant mixtures: Density, vapour-liquid equilibrium, and heat capacity data and modelling

“…It worth to note that recently, Jaubert and coworkers added six fluorinated groups to the well-known Enhanced-PPR78 model, allowing for the estimation of the temperature-dependent binary interaction parameters kij(T) in the PR EoS , thereby creating a predictive model that is able to describe the thermophysical properties of multi-component systems that contain a fluorocompound mixed with CO2 and/or an alkane. (Jean-Noël and Lucie, 1999;Jun-Wei et al, 2017).…”

Survey of Data and Models for Refrigerant Mixtures Containing Halogenated Olefins

“…Due to the broad spectrum of modeling approaches that have been considered for blends containing halogenated olefins, any survey will be necessarily incomplete. Equation of state approaches have included group-contribution volume translated Peng-Robinson (GC-VTPR), − perturbed-chain polar SAFT, , cubic plus association (CPA), , and predictive Peng-Robinson (PPR78). , With very few exceptions, insufficient detail is provided in the literature to verify the performance of the proposed equations of state. While these models can in many cases provide adequate representation of the vapor–liquid equilibrium (especially the cubic equations of state), simultaneously representing all thermodynamic properties with a consistent model formulation is challenging.…”

Comparison of CP-PC-SAFT and PC-SAFT with k12 = 0 and PPR78 in Predicting Binary Systems of Hydrocarbons with Squalane, n-dodecylbenzene, cis-decalin, Tetralin, and Naphthalene at High Pressures

“…Recently, the parameter matrix of the PPR78 model was revised to cover phase equilibria, excess enthalpy, and heat capacity data simultaneously. The resulting model was called E -PPR78 (enhanced predictive Peng–Robinson, 1978). − Moreover, recently Piña-Martinez et al have demonstrated that the Peng–Robinson EoS is nearly identical to an optimal form of the two-parameter cubic EoS. Nevertheless, the theoretically advanced approaches belonging to a family of the statistical association fluid theory (SAFT) may perform better in the cases of certain auxiliary properties such as sound velocities, especially in the elevated pressure range …”