Vapor-Recirculating Equilibrium Still

Hipkin, Howard G.; Myers, H. S.

doi:10.1021/ie50540a035

Cited by 53 publications

(36 citation statements)

References 3 publications

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“…The constants required for these calculations are summarized in Table I. n-heptane-toluene (29), and cyclohexane-toluene (35). of mercury are available for the binary systems n-heptane-cyclohexane (36,59).…”

Section: Applicationsmentioning

confidence: 99%

Multicomponent Vapor-Liquid Equilibria from Binary Data

Black¹

1959

Ind. Eng. Chem.

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A D v m T A m s of calculating vaporliquid equilibria in multicomponent systems from data for the pure components and individual binaries are obvious. The relative simplicity of the experimental determination of binary data as contrasted to multicomponent data is a basic advantage. The main value of the calculation method is lost if the data required for its application become excessive or too difficult to obtain.Several types of binary data conveniently furnish activity coefficients and in some cases provide a double check on the data and their thermodynamic consistency. Such binary data are already available for many systems. They are becoming more and more available from measurements of total pressures, boiling points, azeotropic data, relative volatilities, and complete vapor-liquid equilibria. Their efficient use in calculating multicomponent systems is of prime importance.Several methods have been reported for calculating vapor-liquid equilibria. Usually vapor-liquid equilibria are calculated by liquid phase activity coefficients. The Margules (3, 7.9,22,34,45,47,57,69) and van Laar-type (4, 6 , 74, 79, 63-65, 67, 69) equations have frequently been applied to representation of the activity coefficients as a function of composition. Another method uses equations relating directly to liquid composition and relative volatilities, or vapor compositions (72, 73,23,38, 46,60).The objective of this article is to show further application of the modified van Laar-type equations ( 6 ) to the calculation of multicomponent vapor-liquid equilibria based only on data for the pure components and their binary mixtures. Phase EquilibriaComplete vapor-liquid equilibria in terms of the liquid, x,, the vapor composition, Y,, the total pressure, P, and the temperature, T , provide more than the minimum data required for a check of the thermodynamic consistency. The pressure-temperature relationship a t liquid composition x , and the vapor composition, Y,, at the corresponding x , and T . or P, provides a double check on the consistency of the data. The two are related through the activity coefficient, yt, according toand at, = r t P W r t P P 9 , = Y,x,/x,Y, (2) A method for calculating the imperfection-pressure coefficients, 0, has been described (5). For a nonpolar substance the only basic data needed are critical temperature, T,, critical pressure, P,, and vapor pressure, Po. For a polar substance a minimum of one individual constant is also required. A vapor density a t one or two temperatures can furnish the required individual constants for each polar substance. Except where special "chemical" effects are present, no binary coefficients are required to represent the imperfection-pressure coefficients for the components in the mixtures.The activity coefficients, y's, are functions of temperature and liquid compositions, 2's. While in many systems the qualitative effect of temperature on the activity coefficients is known, exact quantitative values are best derived empirically from data at more than one temperature. For ...

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Section: Applicationsmentioning

confidence: 99%

Multicomponent Vapor-Liquid Equilibria from Binary Data

Black¹

1959

Ind. Eng. Chem.

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“…This selection is due to that the interfacial behavior of the mixture was already characterized by experimentation and by a theoretical approach using SGT, 70 this study showed good agreement between theory and experimentation when β ij = 0 is used for all pairs. In this example, the mixture will be modeled with PRSV EoS and QMR mixing rule, were k ij were fitted to experimental phase equilibria data 71–73 . In Listing 18 the phase equilibria of a mixture of global composition z 1 = 0.5 and z 2 = 0.25 at 344.15 K and 40 bar is computed.…”

Section: Sgt Implementationmentioning

confidence: 99%

“…In this example, the mixture will be modeled with PRSV EoS and QMR mixing rule, were k ij were fitted to experimental phase equilibria data. [71][72][73] In Listing 18 the phase equilibria of a mixture of global composition z 1 = 0.5 and z 2 = 0.25 at 344.15 K and 40 bar is computed. Similarly, as the binary example, after the equilibrium is solved the density vectors are computed for each phase and then SGT can be applied to the mixture.…”

Section: Sgt Implementationmentioning

confidence: 99%

Phasepy: A Python based framework for fluid phase equilibria and interfacial properties computation

Chaparro

Mejı́a

2020

J Comput Chem

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Phasepy is a Python based package for fluid phase equilibria and interfacial properties calculation from equation of state (EoS). Phasepy uses several tools (i.e., NumPy, SciPy, Pandas, Matplotlib) allowing use Phasepy under Jupyter Notebooks. Phasepy models phase equilibria with the traditional ϕ-γ and ϕ-ϕ approaches, where ϕ (fugacity coefficient) can be modeled as a perfect gas, virial gas or EoS fluid, whereas γ (activity coefficient) can be described by conventional models (NRTL, Wilson, Redlich-Kister expansion, and the group contribution modified-UNIFAC). Interfacial properties are based on the square gradient theory couple to ϕ-ϕ approach. The available EoSs are the cubic EoS family extended to mixtures through the quadratic, modified-Huron-Vidal, and Wong-Sandler mixing rules. Phasepy allows to analyze phase stability, compute phase equilibria, interfacial properties, and optimize their parameters for vapor-liquid, liquid-liquid, and vapor-liquid-liquid equilibria for multicomponent mixtures. Phasepy implementation, and robustness are illustrated for binary and ternary mixtures.

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“…Damit ist eine physikalisch sinnvolle Deotnng der freien ExzeSenthalpie einer Qruppe von binLren SjStemen moglich. , 65,[67][68][69][70][71], so stellt man trotz des unpolaren Charakters aller Komponenten betrachtliclze Unterschiede fest. Unter der sicher exakten Bnnahme, da13 sich die Art der zwischenmolekularen Wechselwirkung in der freien ExzeRenthalphie GE am eindeutigsten widerspiegelt , lassen sich die experimentellen Aussa-…”

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Zur Zwischenmolekularen Wechselwirkung in binären Systemen Tetrachlormethan‐Aromaten

Kind

Bittrich

1970

J. Prakt. Chem.

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Es werden Beziehungen für die Separierung der freien Exzeßenthalpien von binären Systemen aus Tetrachlormethan mit Benzol und verschiedenen alkylsubstituierten Benzolen entsprechend den Formen der zwischenmolekularen Wechselwirkungen abgeleitet. Für die nichtspezifische Wechselwirkung wurde das Kontinuumsmodell von LINDER auf binäre Systeme ausgedehnt. Der Beitrag der Elektronendonator‐Akzeptor‐Wechselwirkung wurde mit einem Modell der idealen Mischung für die AB‐Bildung berechnet und die Gleichgewichtskonstanten aus der Beziehung zum Ionisationspotential mit Hilfe der experimentellen Werte von PRAUSNITZ u. a. für Benzol, Mesitylen und Hexamethylbenzol berechnet. Der aus der Störung der Flüssigkeitsstruktur der aromatischen Komponente resultierende Anteil wurde nach einem Modell der ideal assoziierten Lösung angesetzt, das Simultangleichgewicht tierativ gelöst und die als adjustierbare Parameter gewonnenen Gleichgewichtskonstanten als Funktion der Ionisierungsenergien diskutiert. Sie sind den von McGLASHAN auf anderem Weg ge wonnenen Konstanten proportional. Damit ist eine physikalisch sinnvolle Deutung der freien Exzeßenthalpie einer Gruppe von binären Systemen möglich.

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Vapor-Recirculating Equilibrium Still

Cited by 53 publications

References 3 publications

Multicomponent Vapor-Liquid Equilibria from Binary Data

Multicomponent Vapor-Liquid Equilibria from Binary Data

Phasepy: A Python based framework for fluid phase equilibria and interfacial properties computation

Zur Zwischenmolekularen Wechselwirkung in binären Systemen Tetrachlormethan‐Aromaten

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