Molecular theory of phase equilibria in model and real associated mixtures. II. Binary aqueous mixtures of inert gases and n-alkanes

Nezbeda, I.; Kolafa, J.; Pavlícˇek, J.; Smith, W. R.
June 1995
Journal of Chemical Physics;6/22/1995, Vol. 102 Issue 24, p9638
Academic Journal
The phase equilibrium properties of a molecular-based model of binary aqueous mixtures are investigated using an extended primitive model (EPW) for water, which incorporates a mean-field attractive term in addition to the interactions given by the primitive model studied in part I of this series of papers. The second component, representing a nonpolar fluid, is modeled by a general hard body with a mean-field attractive term. Analytical expressions for the Helmholtz free energy of this precisely defined molecular model are obtained from statistical mechanical theory, as a function of the molecular size, the mean-field interaction term, and the shape of the second component. The predictions of our model are compared with the behavior of two classes of real aqueous mixtures: Group A={water+inert gases, hydrogen} and Group B={water+n-alkanes}. The phase equilibrium properties are studied as a function of the ratio of the critical temperature τ and critical volume λ with respect to the corresponding quantities for water, and the global phase diagram (i.e., the type of phase behavior and its dependence on the model parameters) is determined. Since τ and λ are obtainable both from our theory and from experiment, our approach thus contains no adjustable parameters. The theory gives qualitatively correct predictions of the phase behavior of these two classes of mixtures, i.e., of the transition between Type IIIc and Type IIId critical line behavior in the Konynenberg and Scott classification scheme, of the presence or absence of pressure minima for Group B mixtures exhibiting Type IIIc behavior, and the dependence of the temperature and pressure of the Type IIIc temperature minimum on the size of the second-component molecule. © 1995 American Institute of Physics.


Related Articles

  • Study of phase equilibrium in benzene-heptane- N-methylpyrrolidone system. Ivanov, I.; Lotkhov, V.; Glebova, Yu.; Chelyuskina, T.; Kulov, N. // Theoretical Foundations of Chemical Engineering;Jul2014, Vol. 48 Issue 4, p337 

    The vapor-liquid equilibrium for a benzene-heptane- N-methylpyrrolidone mixture is experimentally studied. The mathematical modeling of phase equilibrium is performed using the NRTL equation. The existence of a binary pseudoazeotrope in the system under study is experimentally found.

  • Modeling phase equilibrium in reaction mixture of methyl tert-butyl ether production. Frolkova, A.; Krupinova, O.; Prokhorova, S. // Theoretical Foundations of Chemical Engineering;Jul2013, Vol. 47 Issue 4, p489 

    The complete mathematical model of phase equilibrium in four-component system forming in the methyl tert-butyl ether production was developed, and the assessment of its separation possibilities have been carried out using special techniques variety.

  • Phase equilibria in pseudoternary systems of IV–VI compounds. Volykhov, A. A.; Yashina, L. V.; Shtanov, V. I. // Inorganic Materials;May2010, Vol. 46 Issue 5, p464 

    Using literature data, experimental data obtained in this study, and a unified thermodynamic model, we have calculated the T-x-y phase diagrams of all the pseudoternary systems formed by the Group 14 chalcogenides: (Ge, Sn, Pb)Te, Pb(S, Se, Te), and Sn(S, Se, Te). The phase diagrams have been...

  • How close to two dimensions does a Lennard-Jones system need to be to produce a hexatic phase? Gribova, Nadezhda; Arnold, Axel; Schilling, Tanja; Holm, Christian // Journal of Chemical Physics;8/7/2011, Vol. 135 Issue 5, p054514 

    We report on a computer simulation study of a Lennard-Jones liquid confined in a narrow slit pore with tunable attractive walls. In order to investigate how freezing in this system occurs, we perform an analysis using different order parameters. Although some of the parameters indicate that the...

  • Concentration Inhomogeneities and Phase Diagrams of Eutectic Systems. Ambrok, A.G.; Nemna, S.V. // Technical Physics Letters;Jun2004, Vol. 30 Issue 6, p452 

    We show that it is possible to determine the regions of compositions with developed concentration inhomogeneities in the liquid phase by analysis of the phase diagrams of binary eutectic systems. © 2004 MAIK “Nauka / Interperiodica”.

  • Supramolecular model of eutectics: Functional materials based on nonautonomous phases. Pervov, V. S.; Makhonina, E. V.; Dobrokhotova, Zh. V.; Dubasova, V. S.; Zarvazhnov, A. Yu. // Inorganic Materials;Nov2009, Vol. 45 Issue 12, p1382 

    New data in favor of the supramolecular theory of eutectics are given. It is shown that, on the basis of metastable states appearing in eutectic compositions, new materials having a functional purpose can be obtained. The concept that explains the pseudo-single-phase character and defect...

  • Study of vapor–liquid equilibrium of mixtures in the field of dilute solutions. Arkharov, A. M.; Savinov, M. Yu.; Poznyak, V. E.; Kolpakov, M. Yu. // Chemical & Petroleum Engineering;Sep2009, Vol. 45 Issue 9/10, p629 

    Studies of phase equilibrium are performed for a series of binary mixtures including Kr–CF4, and the good reproducibility of experimental results is demonstrated with a change in concentration of micro-impurities in the end product.

  • Demixing and confinement of non-additive hard-sphere mixtures in slit pores. Almarza, N. G.; Martín, C.; Lomba, E.; Bores, C. // Journal of Chemical Physics;2015, Vol. 142 Issue 1, p1 

    Using Monte Carlo simulation, we study the influence of geometric confinement on demixing for a series of symmetric non-additive hard spheres mixtures confined in slit pores. We consider both a wide range of positive non-additivities and a series of pore widths, ranging from the pure two...

  • Thermodynamic simulation of formation of phase equilibrium in multicomponent alloys that undergo layering accompanied by formation of magnetically ordered phase. Belyakov, N.; Vintaikin, B. // Metal Science & Heat Treatment;May2011, Vol. 53 Issue 1/2, p39 

    n approach to investigation of phase equilibrium in multicomponent alloys, which undergo layering accompanied by formation of a magnetically ordered phase, with the help of a numerical model is described. Multicomponent alloys based on the Fe - Cr - Co system are considered as an example.


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics