Javier Vijande
@uvigo.gal
Departament of Applied Physics
University of Vigo
Scopus Publications
Scopus Publications
Javier Vijande, Manuel M. Piñeiro, and José L. Legido
American Chemical Society (ACS)
A new perturbative group-contribution method has been recently developed (J. Vijande, M. M. Pineiro, J. L. Legido, D. Bessieres, Ind. Eng. Chem. Res. 2010, 49, 9394) that is intended to obtain the PC-SAFT molecular equation of state characteristic parameters of nonassociating compounds on a functional group contribution scheme basis. The method takes into account the proximity effect among functional groups within the molecule in order to describe the deviations of shorter chain molecules’ characteristic parameters from the regular trend observed for the longer chain ones. The molecular parameters are considered as a linear combination of reference functional-group parameters and their mutual perturbations, which are responsible of the deviations from the reference values, and they were optimized to the available molecular parameters of nonassociating compounds published in literature. Now, this method has been extended to associating compounds as primary alcohols and amines in order to check the ability ...
Josefa Salgado, Teresa Regueira, Luis Lugo, Javier Vijande, Josefa Fernández, and Josefa García
Elsevier BV
Abstract Densities and viscosities were determined for binary mixtures of 2,2,2-trifluoroethanol (TFE) and 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]), 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF6]) or 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([bmim][NTf2]) over the entire range of composition. The experimental measurements were carried out at temperatures ranging from 278.15 K to 333.15 K, at atmospheric pressure. The densities and viscosities of the pure ionic liquids and their mixtures with TFE were described successfully by an empirical third-order polynomial and by the Vogel–Fulcher–Tammann equation, respectively. In addition, excess molar volumes and viscosity deviations were determined from densities and viscosities of mixtures, respectively, and fitted by using the Redlich–Kister equation.
Moisés R. Currás, Javier Vijande, Manuel M. Piñeiro, Luis Lugo, Josefa Salgado, and Josefa García
American Chemical Society (ACS)
A novel refrigerant−absorbent system for absorption refrigeration based on ionic liquids as absorbents and a fluoroalcohol as the refrigerant is analyzed. New data of densities at several temperatures in the 283.15−333.15 K range and several pressures up to 40 MPa have been measured. Experimental data have been used to study the behavior and influence of the temperature, pressure, and composition on the isothermal compressibility and the isobaric thermal expansion coefficient. In addition, vapor pressures and saturated density data of the refrigerant 2,2,2-trifluoroethanol were used to determine PC-SAFT parameters, whereas for the absorbent 1-butyl-3-methylimidazolium tetrafluoroborate the molecular parameters were optimized using density data at atmospheric pressure. Using these calculated PC-SAFT parameters, PVT behavior, derived properties and vapor pressures were reasonably well predicted.
Javier Vijande, Manuel M. Piñeiro, José L. Legido, and David Bessières
American Chemical Society (ACS)
A new group-contribution method to obtain the PC-SAFT molecular parameters of nonassociated compounds (linear alkanes, branched alkanes, linear monoethers, and esters) is developed on the basis of their regular trends against molecular mass. The method takes into account the proximity effect among all functional groups of a molecule in order to describe the deviations of shorter chain molecular parameters from the regular trend observed for the larger chain ones. The group-contribution scheme considers the molecular parameters as a linear combination of reference functional-group parameters and their mutual perturbations, which are responsible for the deviations from the reference ones. Both types of parameters (the reference functional-group parameters and the mutual perturbations) are optimized to the available molecular parameters published in the literature and obtained by direct fitting from experimental data of saturation pressures and saturated liquid densities.
Javier Vijande, Manuel M. Piñeiro, Josefa García, José Luis Valencia, and José Luis Legido
American Chemical Society (ACS)
New experimental densities and surface tensions for binary mixtures of {heptane + 1-butanol, + 1-hexanol, and + 1-octanol} in a temperature range of (288.15, 293.15, 298.15, 303.15, and 308.15) K are reported for the whole composition range. Densities were measured with an Anton Paar DMA 4500 densimeter. Surface tensions were measured using a Lauda TVT2 automated tensiometer, which uses the principle of the pending drop volume. The experimental data of pure liquids and mixtures have been used to calculate excess molar volumes and surface tension deviations of the mixtures as a function of mole fractions.
Manuel M. Piñeiro, Josefa García, Beatriz E. de Cominges, Javier Vijande, José Luis Valencia, and José Luis Legido
Elsevier BV
Abstract New experimental densities and surface tensions for n-nonane + 1-hexanol at 288.15, 298.15 and 308.15 K are reported. Densities were measured with an Anton Paar DMA 4500 densimeter, and surface tensions using a Lauda TVT2 automated tensiometer, which uses the principle of the pending drop volume. The experimental data of pure liquids and mixtures have been used to calculate excess molar volumes and surface tension deviations of n-nonane + 1-hexanol as a function of mole fractions. A comparative study of these properties together with those available in the literature for the n-alkane + 1-alkanol mixtures has been performed. In addition, the magnitude of these experimental quantities is discussed in terms of the nature and type of intermolecular interactions in binary mixtures.
Javier Cendón, Javier Vijande, José Luis Legido, and Manuel M. Piñeiro
American Chemical Society (ACS)
Experimental high-pressure density data for the binary mixture of methyl nonafluorobutyl ether + hexane were determined. The pressure range considered was 0.1 to 25 MPa, and densities were measured along three isotherms, at temperatures of (283.15, 298.15, and 313.15) K. An Anton Paar DMA 4500 vibrating-tube densimeter, connected to a high-pressure measuring cell, was used for density measurement. Experimental data for the mixture were fitted using a modified Tait equation. Excess molar volumes were as well calculated and correlated, using a modified Redlich−Kister equation, which includes a temperature- and pressure-dependent factor.
Javier Cendón, Manuel M. Piñeiro, David Bessières, Javier Vijande, and José Luis Legido
American Chemical Society (ACS)
Densities at high pressures for the binary mixture of methylnonafluorobutyl ether + hexane were measured, as well as those corresponding to both pure fluids, in a pressure range from (0.1 to 25) MP...
J. Vijande, M. M. Piñeiro, D. Bessières, H. Saint-Guirons, and J. L. Legido
Royal Society of Chemistry (RSC)
A description of the volumetric behaviour of segregated hydrofluoroethers has been carried out using PC-SAFT EOS. Characteristic parameters for several molecules were calculated where experimental data were available, and accurate results were obtained for compressed and saturated liquid density estimation, as well as for saturation curves. A functional group contribution scheme is proposed also for the calculation of the mentioned PC-SAFT EOS characteristic parameters, and this approach reproduces adequately the dependence on molecular structure of the parameters calculated in this work, and also gives good estimations when the parameters are extrapolated for other molecules of the same family.
Javier Vijande, Manuel M Piñeiro, Laura Mosteiro, and José Luis Legido
Elsevier BV
Abstract In this work, the characteristic parameters for the interaction of carbonate–hydroxyl pair for the Nitta–Chao model have been calculated using an updated data base of vapour–liquid equilibria, activity coefficients at infinite dilution, excess molar enthalpies and excess molar volumes of carbonate+1-alkanol binary mixtures. In the process of optimisation of the interaction parameters a Genetic Algorithm (GA) has been used.
M.M Piñeiro, B.E de Cominges, J Vijande, J Garcı́a, and J.L Legido
Elsevier BV
Abstract The interaction between cyclic alkane (CH 2 r ) and hydroxyl (OH) structural groups was revised within the framework of Nitta Chao group contribution model. New interaction parameters were calculated using an updated database, and previous results were clearly improved. Comparison was established with other group contribution models (UNIFAC, DISQUAC).
J.L. Legido, J. Vijande, B.E. de Cominges, J. Garcı́a, T.P. Iglesias, S. Garcı́a-Garabal, and J. Fernández
Elsevier BV
Abstract An updated database with experimental values on vapor–liquid equilibria, activity coefficient at infinite dilution, enthalpies of mixing and excess molar volumes of alkyl alkanoate+1-alkanol binary systems was used to redetermine structure and interaction parameters of the Nitta–Chao model. We have compared the theoretical results obtained with the Nitta–Chao model and our parameters with the experimental data. The percentual mean deviations with the parameters calculated in this work are quite good for all properties studied. We have used the same database to analyse the quality of the predictions of three versions of UNIFAC model for this type of mixtures.
S.M. Pereira, T.P. Iglesias, J.L. Legido, L. Rodrı́guez, and J. Vijande
Elsevier BV
Abstract Refractive indices were measured over the entire composition range at atmospheric pressure for the binary mixtures CH3OH with CH3OCH2(CH2OCH2)3CH2OCH3(2,5,8,11,14 pentaoxapentadecane, or Tegdme) and CH3OCH2(CH2OCH2)nCH2OCH3(n=3–9) (Pegdme 250) at temperatures from 293.15 K to 333.15 K. The experimental values were fitted by a polynomial equation in mole fraction.
José Legido, Lino Rodríguez, Javier Vijande, Josefa García, Teresa Iglesias, and Josefa Fernández
Old City Publishing, Inc
J.L. Legido, J. Vijande, J. García, T.P. Iglesias, E.R. López, and J. Fernández
Elsevier BV
We have estimated the interaction parameters for ether and hydroxyl groups using an extensive experimental database of vapour-liquid equilibria, activity coefficients at infinite dilution, enthalpies of mixing and volumes of mixing of linear monoether + 1-alkanol binary systems. The theoretical results obtained with the parameters proposed are significantly closer to the experimental values than those determined with the parameters of Eckart et al. In addition, the values of thermodynamic properties obtained by the Nitta-Chao model with both set of parameters have been compared with the predictions resulting from other models, such as the DISQUAC model and the UNIFAC model, in its original version and those of Dang and Tassios, Larsen et al. (UNIFAC-Lingby) and Gmehling et al. (UNIFAC-Dortmund).
M.J. Souza, J. Vijande, E. Jiménez, C. Franjo, L. Segade, J.L. Legido, and M.I. Paz Andrade
Elsevier BV
Abstract Excess molar volumes at 298.15 K of {x1 C2H5CO2(CH2)2CH3 + x2 CH3CO(CH2)3CH3 + x3 Cl(CH2)5CH3} and of the binary mixtures {x1 C2H5CO2(CH2)2CH3 + (1 − x1) CH3CO(CH2)3CH3}, {x1 C2H5CO2(CH2)2CH3 + (1 − x1) Cl(CH2)5CH3} and {x1 CH3CO(CH2)3CH3 + (1 − x1) Cl(CH2)5CH3} were determined using an Anton Paar DMA 60 602 densimeter. All the experimental values were compared with the results obtained by empirical expressions for estimating ternary properties from binary results. Variable-degree polynomials have been fitted to the results.
J. Vijande, J.L. Legido, T.P. Iglesias, E. López, and J. Fernández
Elsevier BV
Abstract In this work we have estimated the structural and interactional parameters of the ether- group for the group-contribution model of Nitta-Chao using a extensive experimental database of thermodynamic properties of ethers (monoethers, polyethers and acetals) and ether + n-alkane and ether + ether mixtures. The results obtained by Nitta-Chao model with this parameters get closer to the experimental values than those obtained with parameters of Eckart et al. (1986). The thermodynamic properties obtained by the Nitta-Chao model with old and new parameters were compared to predictions by other models such as Flory (1965) theory, DISQUAC (Kehiaian, 1977) model and UNIFAC model (versions of Dang and Tassios, 1986, and Larsen et al., 1987).
M. López, E. Carballo, J.L. Legido, J. Salgado, J. Vijande, and M.I. Paz Andrade
Elsevier BV
M. López, E. Carballo, C. Franjo, J. Salgado, J. Vijande, and J.L. Legido
Elsevier BV
Abstract Excess molar enthalpies at the temperature 298.15K were measured for {x1CH3CH2COOCH2CH3+x2CH3(CH2)4CH3+ (1 −x1−x2)CH3(CH2)v−2CH3}, (v= 10, 12), as for {x1CH3CH2COOCH2CH3+ (1 −x1)CH3(CH2)v−2CH3}, (v= 10, 12), using a Calvet microcalorimeter. The experimental results were compared with those calculated by using the Nitta-Chao, UNIFAC I, and UNIFAC II models.