Grupo Especializado en Termodinámica de los Equilibrios entre Fasesenglish versionGETEF emblema


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Año 1994

  • Barbes, B; Garcia, I; Gonzalez, JA; Cobos, JC; Casanova, C; Excess properties of (an n-alkoxyethanol + an organic-solvent). VI. VmE {xCH3(CH2)ν-O(CH2)2O(CH2)2OH+(1-x)C6H5CH3} for ν=1, 2, and 4 at the temperature 298.15 K; J Chem Thermodyn, 26 (8) 1994 791-795
The excess volumes VE at the temperature 298.15 K for three (alkoxyethanol + toluene) mixtures have been measured over the whole mole-fraction range from densities measured with a vibrating-tube densimeter. The alkoxyethanol was 2-(2-methoxyethoxy)ethanol or 2-(2-ethoxyethyoxy)ethanol or 2-(2-butoxyethoxy)ethanol. The excess volumes curves are sigmoid with a maximum in the rich region of toluene. The excess volumes increase as the alkyl chain length of the alkoxyethanol decrease.
  • Gonzalez, JA; de la Fuente, IG; Cobos, JC; Casanova, C; Thermodynamics of mixtures containing linear monocarboxylic acids. I. DISQUAC predictions on molar excess gibbs energies, molar excess enthalpies and solid-solid equilibria for mixtures of linear monocarboxylic acids with organic-solvents; Fluid Phase Equilibr, 99 1994 19-33
Mixtures of linear monocarboxylic acids and n-alkanes, cyclohexane, benzene or tetrachloromethane are studied in the framework of DISQUAC. The model gives a fairly good representation of the molar excess Gibbs energy GE, and of solid liquid equilibria. Larger differences from experimental data are found when predicting the molar excess enthalpy HE; these are probably due to errors in the measured data. A method to improve DISQUAC results by fitting geometrical parameters of the ethanoic acid is also described briefly.
  • Yahiaoui, A; Gonzalez, JA; Ait-Kaci, A; Jose, J; Kehiaian, HV; Isothermal vapor liquid equilibria for the 2-butanone plus benzene plus n-octane system; Fluid Phase Equilibr, 98 1994 179-187
Vapor-liquid equilibrium (VLE) data were measured for the ternary 2-butanone(1) + benzene(2) + n-octane(3) system using an isoteniscope of our design over the temperature range (298.05 - 323.10) K. The data are examined on the basis of the DISQUAC group contribution model. In terms of DISQUAC, the mixture is characterized by three types of: contact: aliphatic/ketone, aliphatic/benzene and benzene/ketone. Only for the latter, the interchange coefficients are not available in the literature, and are estimated in this work using VLE and excess enthalpy data for the binary 2-butanone + benzene system. Applying the same parameters to the ternary system under study, DISQUAC yields total pressures values which are 3% lower than the experimental results.
  • Gonzalez, JA; de la Fuente, IG; Cobos, JC; Casanova, C; Domanska, U; DISQUAC application to SLE of binary-mixtures containing long-chain 1-alkanols (1-tetradecanol, 1-hexadecanol, 1-octanol or 1-eicosanol) and n-alkanes (C8 - C16); Ber Bunsen-Ges Phys Chem Chem Phys, 98 (7) 1994 955-959
Thirty-four sets of data on solid-liquid equilibria for the entitled mixtures are examined in terms of DISQUAC. On the basis of data for systems containing n-octane, new first dispersive interchange coefficients are given for the hydroxyl/aliphatic contacts involved. They are constant from 1-hexadecanol. The remainder interchange coefficients are kept the same as in our previous works. The relative standard deviations for the equilibrium temperatures are less than 0.025 for all the mixtures investigated. Results depend on the difference in size of the mixture compounds.
  • Gonzalez, JA; de la Fuente, IG; Cobos, JC; Casanova, C; Application of DISQUAC to binary-liquid organic mixtures containing 1-alkanols and CCL4; Thermochim Acta, 237 (2) 1994 261-275
The data available in the literature on vapour-liquid equilibria (VLE), molar excess Gibbs energies GE, molar excess enthalpies HE, activity coefficients γi, and partial molar excess enthalpies HiE,∞ at infinite dilution of 1-alkanol(1) + tetrachloromethane(2) mixtures are examined on the basis of the DISQUAC group contribution model.
The components of the mixtures are characterized by three types of surface groups: hydroxyl (OH group), alkane (CH3 or CH2 groups), and tetrachloromethane (CCl4 group). The alkane/CCl4 and alkane/hydroxyl interaction parameters are available in the literature. The parameters for the hydroxyl/CCl4 interactions are reported in this work.
The model provides a good description of the VLE and of the related GE data. For the HE data, surprising larger discrepancies are encountered for systems containing 1-propanol or 1-butanol. The temperature dependence of the HE values is fairly well represented. Predictions for the natural logarithms of the activity coefficients at infinite dilution and on HiE,∞ are similar to those for other 1-alkanol(1) + organic solvent(2) mixtures.
  • Gonzalez, JA; de la Fuente, IG; Cobos, JC; Casanova, C; Domanska, U;  Solid-liquid equilibria using DISQUAC - Prediction for 1-alkanol plus n-alkane systems; Fluid Phase Equilibr, 94 1994 167-179
Using the available interaction parameters for the hydroxyl/aliphatic contacts, the ability of the DISQUAC group contribution model to predict the solid-liquid equilibrium (SLE) is investigated. Twenty-eight sets of available data in the literature on solid-liquid equilibria for 1-alkanol(1) + n-alkane(2) systems are examined, neglecting transitions or miscibility in the solid phase. The mixtures studied contain 1-alkanols from ethanol to 1-eicosanol and n-alkanes from n-heptane to n-hexacosane. The relative standard deviations for the solid-liquid equilibrium temperatures are less than 0.02 K for all the mixtures investigated. The SLE curves are usually well represented by the model, even at low temperatures.
  • Gonzalez, JA; de la Fuente, IG; Cobos, JC; Casanova, C; Estimation of DISQUAC interchange energy parameters for 1-alkanols plus benzene, or plus toluene mixtures; Fluid Phase Equilibr, 93 1994 1-22
The data available in the literature on vapour-liquid equilibria (VLE), molar excess Gibbs energies (GE), molar excess enthalpies (HE), molar excess heat capacities (CPE), activity coefficients (γi) and partial molar excess enthalpies (HiE,∞) at infinite dilution of 1-alkanol(1) + benzene(2), or + toluene(2) mixtures are examined on the basis of the DISQUAC group contribution model. For a more sensitive test of DISQUAC, the azeotropes, obtained from the reduction of the original isothermal VLE data, are also examined for a number of systems.
The components in the mixtures are characterized by three types of groups of surfaces: hydroxyl (OH group), alkane (CH3 or CH2 groups), and aromatic (C6H6 or C6H5 groups in benzene or in toluene, respectively; both groups considered as different). The alkane/aromatic and alkane/hydroxyl contact parameters are available in the literature. The parameters for the hydroxyl/benzene and hydroxyl/toluene interactions are reported in this work. The quasichemical parameters are common for the whole set of alcohols (except the first interchange coefficient of methanol, which is different from that for the remaining alcohols), and do not depend on the aromatic molecule considered. Such dependence is encountered only for the second dispersive parameters. These interchange coefficients together with the first ones increase regularly with the size of the alcohol, although, from ethanol, the former are kept the same for each pair of alcohols. The third dispersive parameters behave in an opposite way to the second ones, and are constant from 1-dodecanol.
The model consistently describes phase equilibria and the molar excess functions. Dependence on temperature of CPE is well represented, even the S-shape of this quantity for the 1-butanol + toluene system at high temperatures. Natural logarithms of activity coefficients at infinite dilution are reasonably well reproduced. Predictions on HiE,∞ are opposite to those for mixtures of 1-alkanols with n-alkanes or cyclohexane. They are surprisingly good in the case of H1E,∞ and somewhat poorer for H2E,∞.
  • Gonzalez, JA; de la Fuente, IG; Cobos, JC; Casanova, C; DISQUAC predictions of phase-equilibria, molar and standard partial molar excess quantities for 1-alkanol plus cyclohexane mixtures; J Solut Chem, 23 (3) 1994 399-420
Literature data for phase equilibria: vapor-liquid VLE, liquid-liquid LLE, and solid-liquid SLE; molar excess Gibbs energies GE, molar excess enthalpies HE; activity coefficients γi and partial molar excess enthalpies HiE,∞ at infinite dilution for 1-alkanol (1) + cyclohexane (2) mixtures are examined by the DISQUAC group contribution model. For a more sensitive test of DISQUAC, the azeotropes, obtained from the reduction of the original isothermal VLE data, are also examined for systems characterized by hydroxyl, alkane and cyclohexane groups. The alkane/cyclohexane and alkane/hydroxyl interaction parameters have been estimated previously. The cyclohexane/hydroxyl interaction parameters are reported in this work. The first dispersive parameters increase regularly with the size of the alkanol; from 1-octadecanol they are constant; an opposite behavior is encountered for the third dispersive parameters, which are constant from 1-dodecanol. The second dispersive parameters decrease as far as 1-propanol and then increase regularly; from 1-octadecanol they are constant. The quasichemical parameters are equal to those for the alkane/hydroxyl interactions. Phase equilibria, the molar excess functions, and activity coefficients at infinite dilution are reasonably well reproduced. Poor results are found for HiE,∞ and DISQUAC predictions for HiE,∞ are strongly dependent on temperature.
  • Gonzalez, JA; de la Fuente, IG; Cobos, JC; Casanova, C; DISQUAC predictions on VLE and HE for ternary mixtures containing 1-alkanols and hydrocarbons; Ber Bunsen-Ges Phys Chem Chem Phys, 98 (1) 1994 106-112
Thermodynamic properties, vapor-liquid equilibrium or excess enthalpy, for a set of 13 ternary mixtures including one or two 1-alkanols and hydrocarbons are studied in the framework of the DISQUAC group contribution model. The study is extended for the binaries involved. The DISQUAC analysis is developed using interchange coefficients available in the literature. No ternary interactions are taken into account.
The average relative standard deviations are 0.02 for pressure in the vapor-liquid equilibria (4 systems); and 0.07 for the excess enthalpy (9 systems).



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