Temperature influence on solution properties of ethanol + n-alkane mixtures

Gayol, A.; Iglesias, M.; Goenaga, José M.; Concha, R.G.; Resa, José M.

doi:10.1016/j.molliq.2006.11.012

Cited by 33 publications

(12 citation statements)

References 27 publications

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“…The application was tested on a set of 270 zeotropic and azeotropic systems of homogeneous binary solutions and 30 non‐homogeneous systems. In addition to the VLE data, values of the excess properties ( v E and h E ) have been used and, also, LLE data of the system studied, extracted from the literature,…”

Section: Results Of the Testmentioning

confidence: 99%

A rigorous method to evaluate the consistency of experimental data in phase equilibria. Application to VLE and VLLE

2017

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This work forms part of a broader study that describes a methodology to validate experimental data of phase equilibria for multicomponent systems from a thermodynamic‐mathematical perspective. The goal of this article is to present and justify this method and to study its application to vapor–liquid equilibria (VLE) and vapor–liquid–liquid equilibria (VLLE), obtained under isobaric/isothermal conditions. A procedure based on the Gibbs‐Duhem equation is established which presents two independent calculation paths for its resolution: (a) an integral method and (b) a differential method. Functions are generated for both cases that establish the verification or consistency of data, δψ for the integral test and δζ for the differential approach, which are statistically evaluated by their corresponding average values [ δtrueψ¯, δtrueζ¯], and the standard deviations [ strue(δψtrue), strue(δζtrue)]. The evaluation of these parameters for application to real cases is carried out using a set of hypothetical systems (with data generated artificially), for which the values are adequately changed to determine their influence on the method. In this way, the requirements of the proposed method for the data are evaluated and their behavior in response to any disruption in the canonical variables (p,T, phase compositions). The conditions for thermodynamic consistency of data are: δtrueψ¯<2, strue(δψtrue)<0.2, δtrueζ¯<5, and s(δξ)<0.2. In systems with VLLE, in addition to the previous criteria, must occur that: δxLLE<0.05 and δTLLE<0.5 K. The new proposed method has been tested with a set of 300 experimental binary systems, biphasic and triphasic, obtained from published bibliography, and the results are compared with those of other tests commonly used for testing thermodynamic consistency. The results show that the greater rigor of the proposed method is mainly due to the simultaneous verification of various independent variables. As a result, the conditions for the new test are verified for fewer systems than using other tests mentioned in the literature (i.e., Fredenslund‐test and direct of Van Ness). Its unique application is sufficient to ensure the consistency of experimental data, without using other tests. © 2017 American Institute of Chemical Engineers AIChE J, 2017

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Section: Results Of the Testmentioning

confidence: 99%

A rigorous method to evaluate the consistency of experimental data in phase equilibria. Application to VLE and VLLE

2017

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“…This model can represent different binary combinations of linear n-alkanes having carbon numbers between 6 and 24 with relative deviations between modeled and experimental data of less than 0.5% for various temperatures. 40 The same model can also describe the liquid densities of binary mixtures of ethanol and different nalkanes 41,42 with relative deviations of less than 0.7%. The expanded uncertainties U are U(T) = 0.025 K and U(x) = 0.002, while the relative expanded uncertainties U r (η′) and U r (σ) are given in the table (level of confidence = 0.95).…”

Section: ■ Experimental Sectionmentioning

confidence: 99%

Section: Experimental Sectionmentioning

confidence: 99%

Liquid Viscosity and Interfacial Tension of Binary and Ternary Mixtures Containing n-Octacosane by Surface Light Scattering

et al. 2019

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In this study, the liquid viscosity and interfacial tension of binary and ternary mixtures containing noctacosane (n-C 28 H 58 ) and different byproducts typically found in the Fischer−Tropsch process were investigated. For the binary mixtures having mole fractions of the byproducts between 0.02 and 0.40, the effects of varying branching, alkyl chain length, and degree of oxygenation in selected byproducts on viscosity and interfacial tension were studied. In detail, the isomers n-decane, 2-methylnonane, and 4-methylnonane were used to study differences in branching for alkanes with the same molecular weight. The 1-alcohols ethanol and 1-dodecanol as well as the carboxylic acids formic acid and acetic acid imply variations in the alkyl chain length and degree of oxygenation. In addition, two ternary systems consisting of n-octacosane, n-decane, and ethanol with mole fractions of 0.6 of either n-alkane and 0.2 for each of the other two components were selected. On the basis of the surface light scattering (SLS) method analyzing microscopic surface fluctuations at macroscopic thermodynamic equilibrium, the liquid viscosity and interfacial tension of the studied mixtures could be determined at saturation conditions at temperatures from (373.15 up to 523.15) K with average expanded measurement uncertainties (k = 2) of (2.7 and 2.4)%. Except for systems containing the two branched alkanes showing a distinct decrease in the interfacial tension even at low mole fractions of 0.025, liquid viscosity and interfacial tension at 423 K are not strongly affected with increasing concentration of the byproducts up to 0.10 compared to the values for pure n-octacosane within relative deviations of 10% and 5%. For the studied binary and ternary systems, simple mixing rules for liquid viscosity and interfacial tension based on the corresponding properties of the pure components are discussed.

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“…Although the amount of disposable ultrasonic data has increased in recent years, in what is referred to complex mixtures, the scarce of information is still important, thus the use of mathematical models is essential for both theoretical studies and industrial technology. Into open literature, different methods are available with varying degrees of success (semi empirical mixing rules, associative equilibrium models, equations of state with mixing rules, or statistical mechanical theories) [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] although in a whole part, such studies and predictions are related to binary mixtures. Usually, large deviations for predictions of ultrasonic properties are observed when biochemical, polar or selfassociative molecules are involved in multicomponent or partial miscible mixtures, due to the considerable non-ideal behaviour and special aggregation into these complex systems, indeed these facts pose significant challenges.…”

Section: Introductionmentioning

confidence: 99%

Temperature dependence of isentropic compressibilities for the ternary mixture Acetone + Methanol + n-Hexane

Iglesias

Andrade

Marino³

2018

International Journal of Thermodynamics

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In this work, the applicability of Free Length and Collision Factor theories to predict multicomponent isentropic compressibilities is analyzed and compared. To this end, appropriate expansions for ternary mixtures were derived from the original works, and then applied to a mixture containing dislike compounds in terms of functional molecular groups. Excess molar volumes from open literature and new experimental ultrasonic velocities of the mixture acetone+methanol+n-hexane were used to compute the corresponding isentropic compressibilities. A good accuracy was obtained when ternary prediction is attempted in this partially soluble mixture at different temperatures by the Collision Factor theory. These results show the versatility of this model for estimation studies in complex multicomponent mixtures enclosing phase splitting.

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Temperature influence on solution properties of ethanol + n-alkane mixtures

Cited by 33 publications

References 27 publications

A rigorous method to evaluate the consistency of experimental data in phase equilibria. Application to VLE and VLLE

A rigorous method to evaluate the consistency of experimental data in phase equilibria. Application to VLE and VLLE

Liquid Viscosity and Interfacial Tension of Binary and Ternary Mixtures Containing n-Octacosane by Surface Light Scattering

Temperature dependence of isentropic compressibilities for the ternary mixture Acetone + Methanol + n-Hexane

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