Activity coefficients at infinite dilution

Gautreaux, M. F.; Coates, J.H.

doi:10.1002/aic.690010419

Cited by 76 publications

(45 citation statements)

References 5 publications

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“…The relationship between the initial slope of the bubble curve and the activity coefficient was given by Gautreaux and Coates [ 12] and, in more modern form, by Thomas et al [ 13]. It has the form ~p2P~…”

Section: Discussionmentioning

confidence: 99%

Design of a high-pressure ebulliometer, with vapor-liquid equilibrium results for the systems CHF2 Cl + CF3 CH3 and CF3 CH2 F + CH2F2

Weber

Silva

1996

Int J Thermophys

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We describe tile design and operation of a new high-pressure metal ebulliometer which can operate at pressures to at least 3 MPa in the range 220400 K. Infinite-dilution activity coefficients are presented for tile system CHF2CI+ CF3-CH 3 at 275 K and for the system CF3-CH2F+CH2F 2 at 260, 280, and 300 K. The Wilson activity coefficient model and a virial coefficient model are applied to these systems, and tile phase equilibrium conditions are calculated. The results are shown to agree well with predicted and with published measured values. The excess enthalpy is calculated and compared with results from a Peng-Robinson equation of state. Vapor densities on the dew curves are given.

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Section: Discussionmentioning

confidence: 99%

Design of a high-pressure ebulliometer, with vapor-liquid equilibrium results for the systems CHF2 Cl + CF3 CH3 and CF3 CH2 F + CH2F2

Weber

Silva

1996

Int J Thermophys

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“…The ebulliometric data are analyzed following the development of Gautreaux and Coates (1955) with additional terms included to account for the vapor-phase nonideality. A rigorous expression for the activity coefficient at infinite dilution can be readily derived in terms of pure component properties and the limiting slope of the temperature vs. composition curve.…”

Section: Discussionmentioning

confidence: 99%

“…Such uncertainty is one reason that infinite dilution activity coefficients have been so little used in the past. Gautreaux and Coates (1955) proposed using y" 25 years ago, but the data then available were inadequate to demonstrate its utility. However, they were aware of the definite advantages in using limiting activity coefficients, if the experimental values were quickly and reliably available.…”

Section: Conclusion and Significancementioning

confidence: 98%

Measurement and application of limiting activity coefficients

et al. 1981

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Infinite dilution activity coefficients (y") in binary liquid mixtures are data of wide practical and theoretical applicability, but their extensive use has been hindered by the experimental limitations of classical vapor-liquid equilibrium techniques. Two new experimental methods for accurate y" determinations are presented. These techniques, both faster and more accurate than classical methods, are complementary, and their applicability to different types of binary systems is discussed. SCOPEThe modern design and modeling of fluid-phase separation equipment require an accurate mathematical representation of chemical activities in a multicomponent liquid mixture. Solution models now use binary data only to represent a multicomponent mixture, and have proven central to the rational design of distillation, absorption, extraction, stripping, or even crystallization units. Although many sets of binary data exist in the literature, the limiting factor in most multicomponent process designs is in the acquisition of valid binary data needed to determine parameters in the mathematical models. For most miscible organic systems, the existing data are in the form of classical VLE (vapor-liquid equilibria) measurements, which are intrinsically slow and difficult experiments. Further, the resulting data, even if accurate, do not contain the most useful information either for a basic understanding of solution behavior or for practical application.It is the purpose of the current study to demonstrate a different approach to gathering the data needed for studying the solution thermodynamics of binary liquid mixtures as well as for designing multicomponent separations. The advantages of using infinite dilution activity coefficients were first proposed over twenty years ago, and their use in design and scale-up has often been demonstrated. However, the actual measurement of such quantities by classical means-either from VLE or LLE data-is very imprecise, and until recently newer experimental methods have been limited in applicability. This work presents two complementary experimental methods for measuring limiting activity coefficients in a wide variety of organic systems. Since these methods are both easier to use and intrinsically more accurate than the classical techniques, the use of limiting activity coefficients presents useful, new experimental and analytical approaches. CONCLUSIONS AND SIGNIFICANCELimiting activity coefficient (7%) data are most effective both in the description of binary mixtures and in the scale-up to multi-component systems. The limiting activity coefficient characterizes the behavior of a single solute molecule completely surrounded by solvent. As such, it generally indicates a maximum nonideality and offers incisive information to the theorist, since the order-disorder effect disappears; it also offers economy of effort to the experimentalist, since this datum has wider applicability than a measurement at any other concentration.The major reason that yx methods have been little used lies in the dif...

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“…Nevertheless, in order to improve [9] lim the evaluation of the integrals in eqs. [2] and [3] pendence of the activity coefficient on pressure makes the correction for isothermic data quite negligible. For this reason, isothermic data were used in this paper to illustrate the expressions obtained.…”

Section: Fundamentalsmentioning

confidence: 99%

“…The reduction of VLE data to obtain the y," values varies from the graphical or analytical extrapolation of a In yi -xi data set (1) to the determination of the limiting slope of temperature or pressure with respect to the liquid phase composition (2)(3)(4)(5)(6). All of these processes require experimental determinations in the composition range near to that of the pure components.…”

Section: Introductionmentioning

confidence: 99%

Integral method for infinite dilution activity coefficients calculation

Chialvo¹

1992

Can. J. Chem.

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An integral method to determine infinite dilution activity coefficients [Formula: see text] from data sets of finite concentration activity coefficients is proposed for binary systems. This method is based upon the integration of the experimental dependence of ln [Formula: see text] over different composition ranges. The limiting behavior of this function is analysed, in order to improve the precision of its integration. The accuracy of this method is demonstrated by the calculation of [Formula: see text] for several systems.

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Activity coefficients at infinite dilution

Abstract: Use of the equations is illustrated.

Cited by 76 publications

References 5 publications

Design of a high-pressure ebulliometer, with vapor-liquid equilibrium results for the systems CHF2 Cl + CF3 CH3 and CF3 CH2 F + CH2F2

Design of a high-pressure ebulliometer, with vapor-liquid equilibrium results for the systems CHF2 Cl + CF3 CH3 and CF3 CH2 F + CH2F2

Measurement and application of limiting activity coefficients

Integral method for infinite dilution activity coefficients calculation

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