Properties of Refrigerants from Cubic Equations of State

2008 ◽  
Vol 59 (5) ◽  
Author(s):  
Viorel Feroiu ◽  
Dan Geana ◽  
Catinca Secuianu
Keyword(s):  
Experimental Data ◽  
Vapor Pressure ◽  
Equations Of State ◽  
Ternary Mixtures ◽  
Volumetric Properties ◽  
Mixing Rules ◽  
Saturation Curve ◽  
Equilibrium Thermodynamic ◽  
Liquid Equilibrium ◽  
Binary And Ternary Mixtures

Vapour � liquid equilibrium, thermodynamic and volumetric properties were predicted for three pure hydrofluorocarbons: difluoromethane (R32), pentafluoroethane (R125) and 1,1,1,2 � tetrafluoroethane (R134a) as well as for binary and ternary mixtures of these refrigerants. Three cubic equations of state GEOS3C, SRK (Soave � Redlich � Kwong) and PR (Peng � Robinson) were used. A wide comparison with literature experimental data was made. For the refrigerant mixtures, classical van der Waals mixing rules without interaction parameters were used. The GEOS3C equation, with three parameters estimated by matching several points on the saturation curve (vapor pressure and corresponding liquid volumes), compares favorably to other equations in literature, being simple enough for applications.

scholarly journals Modelling of volumetric properties of binary and ternary mixtures by CEOS, CEOS/Ge and empirical models

2007 ◽  
Vol 72 (12) ◽  
pp. 1437-1463 ◽  
Author(s):  
Bojan Djordjevic ◽  
Slobodan Serbanovic ◽  
Ivona Radovic ◽  
Aleksandar Tasic ◽  
Mirjana Kijevcanin
Keyword(s):  
Molar Volume ◽  
Excess Molar Volume ◽  
Equations Of State ◽  
Ternary Systems ◽  
Empirical Models ◽  
Ternary Mixtures ◽  
Excess Properties ◽  
Volumetric Properties ◽  
Excess Molar Enthalpy ◽  
Binary And Ternary Mixtures

Although many cubic equations of state coupled with van der Waals-one fluid mixing rules including temperature dependent interaction parameters are sufficient for representing phase equilibria and excess properties (excess molar enthalpy HE, excess molar volume VE, etc.), difficulties appear in the correlation and prediction of thermodynamic properties of complex mixtures at various temperature and pressure ranges. Great progress has been made by a new approach based on CEOS/GE models. This paper reviews the last six-year of progress achieved in modelling of the volumetric properties for complex binary and ternary systems of non-electrolytes by the CEOS and CEOS/GE approaches. In addition, the vdW1 and TCBT models were used to estimate the excess molar volume VE of ternary systems methanol + chloroform + benzene and 1-propanol + chloroform + benzene, as well as the corresponding binaries methanol + chloroform, chloroform + benzene, 1-propanol + chloroform and 1-propanol + benzene at 288.15-313.15 K and atmospheric pressure. Also, prediction of VE for both ternaries by empirical models (Radojkovic, Kohler, Jackob-Fitzner, Colinet, Tsao-Smith, Toop, Scatchard, Rastogi) was performed.

scholarly journals Kelvin’s Dissymmetric Models and Consistency Conditions of Multicomponent Gas-Liquid Equilibrium and Capillary Condensation

2016 ◽  
Vol 2016 ◽  
pp. 1-21
Author(s):  
Mikhail Panfilov ◽  
Alexandre Koldoba
Keyword(s):  
Mathematical Theory ◽  
Equations Of State ◽  
Capillary Condensation ◽  
Ternary Mixtures ◽  
Chemical Components ◽  
Liquid Equilibrium ◽  
Suggested Approach ◽  
New Approach ◽  
Binary And Ternary Mixtures ◽  
Multicomponent Gas

To describe phase equilibrium of mixtures, we develop a nonclassical approach based on using different equations of state for gas and liquid. We show that not all the types of EOS are admissible but only those which verify some specific conditions of consistency. We developed the mathematical theory of this new approach for pure cores and for mixtures, in presence and absence of capillary forces, which leads to explicit analytical relationships for phase concentrations of chemical components. Several examples of comparison with experimental data for binary and ternary mixtures illustrate the feasibility of the suggested approach.

scholarly journals Drawing PT-phase envelopes and calculating critical points for multicomponent systems using flash calculations

2020 ◽  
Vol 15 (1) ◽  
pp. 46-54
Author(s):  
L. A. Toro
Keyword(s):  
Experimental Data ◽  
Equation Of State ◽  
Critical Points ◽  
Isopropyl Alcohol ◽  
Equations Of State ◽  
Mixing Rules ◽  
Mixing Rule ◽  
Multicomponent Systems ◽  
Activity Coefficient Model ◽  
Robinson Equation

Objectives. This study aims to draw PT-phase envelopes and calculate the critical points for multicomponent systems using flash calculations.Methods. Flash calculations with an equation of state and a mixing rule were used to construct phase envelopes for multicomponent systems. In general, the methodology uses the Soave–RedlichKwong equation of state and Van der Waals mixing rules; and the Peng–Robinson equation of state with Wong–Sandler mixing rules and the non-random two-liquid activity coefficient model.Results. The method was applied to the following mixtures: ethane (1)–butane (2) (four different compositions); ethane (1)–propane (2) (four different compositions); butane (1)–carbon dioxide (2) (three different compositions); C2C3C4C5C6 (one composition); isobutane–methanol–methyl tertbutyl ether–1-butene (one composition); and propylene–water–isopropyl alcohol–diisopropyl ether (one composition).Conclusions. Our results agreed to a large extent with the experimental data available in the literature. For mixtures that contained CO2 , the best results were obtained using the PengRobinson equation of state and the Wong–Sandler mixing rules. Our methodology, based on flash calculations, equations of state, and mixing rules, may be viewed as a shortcut procedure for drawing phase envelopes and estimating critical points of multicomponent systems.

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