Showing papers on "UNIQUAC published in 2007"
TL;DR: In this article, the Redlich-Kister equation was used to predict the dynamic viscosities of methanol or ethanol with water, ethyl acetate, and methyl acetate.
312 citations
TL;DR: In this article, the activation energy of lactic acid esterification and hydrolysis reactions were found to be 52.29 and 56.05 kJ −1, respectively.
143 citations
TL;DR: In this article, experimental densities, speeds of sound and refractive indices of the binary mixtures of ethanol with MMIM MeSO4 (1,3-dimethylimidazolium methyl sulfate), BMIM MESO 4 (1-butyl-3-methylimidsioxolium hexafluorophosphate), OMIM PF6 (1 methyl-3 -octylimidaxoliumhexafluoric acid hexa-phosphate) were determined from T = (293.15 to 303.15)
111 citations
TL;DR: In this article, reaction kinetics are presented for the reversible esterification reaction of citric acid with ethanol to form tri-ethyl citrate via mono-ethyl and di-ethylcitrates.
Abstract: Reaction kinetics are presented for the reversible esterification reaction of citric acid with ethanol to form tri-ethyl citrate via mono-ethyl and di-ethyl citrates. The reaction was studied in batch isothermal experiments, self-catalyzed homogeneously by citric acid and the formed mono- and di-ethyl citrates, and heterogeneously catalyzed by macroporous Amberlyst-15 ion-exchange resin catalyst. Experimental data were obtained between 78 and 120 °C at different mole ratios of ethanol to citric acid and catalyst concentrations up to 5 wt % ion-exchange resin. The kinetics of ethanol etherification to form di-ethyl ether were included in the investigation. Kinetic modeling was performed using a pseudo-homogeneous UNIQUAC-based activity model, taking into consideration the rate of self-catalyzed esterification and the side reaction to form diethyl ether. The activity coefficients for the tri-ethyl citrate−ethanol and tri-ethyl citrate−water binary pairs were obtained from experimental vapor−liquid equilibri...
75 citations
TL;DR: Solid-liquid equilibria with immiscibility in the liquid phase were detected with the aromatic hydrocarbons ethylbenzene and propylbenzone and the basic thermodynamic properties of pure ionic liquid have been determined by differential scanning calorimetry.
Abstract: The (solid + liquid) phase equilibria and (liquid + liquid) phase equilibria of binary mixtures containing quaternary phosphonium salt-tetrabutylphosphonium methanesulfonate and alcohols or alkylbenzenes were investigated. The systems {[(CH(3)CH(2)CH(2)CH(2))4P][CH(3)SO(3)] + 1-butanol, or 1-hexanol, 1-octanol, 1-decanol, or 1-dodecanol} and {[(CH(3)CH(2)CH(2)CH(2))4P][CH(3)SO(3)] + benzene, or toluene, ethylbenzene, or propylbenzene} have been measured by a dynamic method at a wide range of temperatures from 220 to 386 K. Solid-liquid equilibria with immiscibility in the liquid phase were detected with the aromatic hydrocarbons ethylbenzene and propylbenzene. The basic thermodynamic properties of pure ionic liquid--the melting point, enthalpy of fusion, enthalpy of solid-solid-phase transition, and glass transition--have been determined by differential scanning calorimetry. The experimental data of systems with alcohols were correlated by means of the UNIQUAC ASM and NRTL1 equations and of systems with alkylbenzenes with Wilson and NRTL equations utilizing parameters derived from the (solid + liquid) equilibrium. The root-mean-square deviations of the solubility temperatures for all calculated data are dependent upon the particular system and the particular equation used.
62 citations
TL;DR: In this paper, the phase equilibria of aromatics separation from the multicomponent system using N-methyl-2-pyrrolidone (NMP), as an extracting agent, have been studied.
Abstract: The phase equilibria of aromatics separation from the multicomponent system [paraffins: (tetradecane + hexadecane + heptadecane) and aromatics (ethylbenzene + 1,3,5-trimethylbenzene + butylbenzene)] using N-methyl-2-pyrrolidone (NMP), as an extracting agent, have been studied. The aromatics in the multicomponent mixture were extracted at different temperatures (293−323 K) and different solvent to feed ratios (0.99−1.89). Such a system is found in the removal of aromatics from middle distillates in petroleum processing. The effects of temperature, solute concentration in the feed, and solvent to feed ratio on solubility, distribution coefficient, selectivity, and yield were investigated. The abilities of nonrandom two liquid (NRTL) and universal quasi-chemical (UNIQUAC) models to predict liquid−liquid equilibria were evaluated. The experimental data of the studied system were regressed to estimate the interaction parameters between each of the seven pairs of components using the two models as a function o...
52 citations
TL;DR: In this article, the UNIFAC-VISCO method was used to predict the dynamic viscosities of the binary mixtures and the interaction parameters of cycloalkanes with primary alcohol (CHcy/-OH) have been determined for their application.
51 citations
TL;DR: The experimental data were correlated with the UNIQUAC and NRTL activity coefficient models on the base of the fixed binary interaction parameters that were obtained from two sub-ternary systems MIBK-water-phenol as discussed by the authors.
49 citations
TL;DR: In this article, the solubility of sodium diclofenac in several solvents such as acetone, ethyl acetate and dimethyl sulfoxide was studied, in the temperature range from 293.15 up to 313.15
48 citations
TL;DR: In this article, a model based on predictive Soave−Redilich−Kwong (PSRK) equation and modified-Huron Vidal (MHV1) mixing rule combined with the UNIQUAC model was used to predict oxygen solubility in toluene.
Abstract: Oxygen solubility in toluene at temperatures from 298.45 K to 393.15 K and pressures up to 1.0 MPa was measured in an autoclave type phase equilibrium apparatus using the total pressure method. Henry coefficients were derived from the mole fractions at experimental pressures and temperatures. A model based on predictive Soave−Redilich−Kwong (PSRK) equation and modified-Huron Vidal (MHV1) mixing rule combined with the UNIQUAC model was used to predict oxygen solubility in toluene. Both experimental and predicted data are in good agreement, which shows that the oxygen solubility increases with increasing temperature and pressure. The results indicate that the solubilization of oxygen in toluene is an endothermic process. An empirical equation of the Henry coefficient was obtained in this work.
42 citations
TL;DR: In this paper, the influence of the alkyl chain length on the cation on the liquid−liquid equilibra (LLE) was measured, and the experimental data was obtained at (313.2 ± 0.5) K and correlated with the UNIQUAC model to obtain the binary interaction parameters.
Abstract: Liquid−liquid-phase equilibria studies of systems containing acidic ionic liquid (IL) + ethylacetate + ethanol or acetic acid are reported, and the influence of the alkyl chain length on the cation on the liquid−liquid equilibra (LLE) was measured. The ILs used are 1-methylimidazolium hydrogen sulfate ([HMIM][HSO4]), 1-ethyl-3-methylimidazolium hydrogen sulfate ([EMIM][HSO4]), and 1-butyl-3-methylimidazolium hydrogen sulfate ([BMIM][HSO4]). The experimental data was obtained at (313.2 ± 0.5) K and correlated with the UNIQUAC model to obtain the binary interaction parameters. All studied systems were of type I, with ethylacetate + IL as immiscible pairs.
TL;DR: In this paper, the experimental VLE data were correlated using the UNIQUAC equation to describe the chemical and phase equilibria simultaneously, for some of the non-reactive binary systems.
TL;DR: In this article, the authors reported consistent vapour-liquid equilibrium data for the binary and ternary systems of diisopropyl ether + isopropyric acid at 30 and 101.3 kPa, respectively, and the activity coefficients of the solutions were correlated with its composition using the Wilson, NRTL and UNIQUAC models.
TL;DR: In this paper, the authors used an all-glass dynamic recirculating still with an ultrasonic homogenizer coupled to the boiling flask for the determination of vapor-liquid-liquid equilibria.
TL;DR: Using the solubility data, transformation analysis has been done and the results confirm these two polymorphs are enantiotropes and Form 1 converts to Form 2 at 95 degrees C.
TL;DR: In this article, isothermal vapor-liquid equilibria measurements for binary and ternary mixtures containing carbon dioxide, 1-heptanol, and n -pentadecane at the temperatures of 298.15 and 316.15 K are reported.
TL;DR: In this paper, a thermodynamic consistent model was developed for calculation of the vapor−liquid equilibria in acid gases (H2S and CO2)−alkanolamine−water system.
Abstract: Thermodynamic modeling of solubility of acid gases in aqueous alkanolamine solutions is essential in design of the absorbers for sweetening of natural gas A thermodynamic consistent model was developed for calculation of the vapor−liquid equilibria in acid gases (H2S and CO2)−alkanolamine−water system This model accounts for both chemical and phase equilibria in liquid and vapor phases For nonideality of species in the liquid phase, the UNIQUAC-NRF equation with ion-pair approach was applied For long-range interaction, the Pitzer−Debye−Huckel term was used The model was applied for correlation of the solubility of acid gases in binary and ternary aqueous solutions of monoethanolamine (MEA) and methyldiethanolamine (MDEA) Also, prediction of the solubility of acid gases in binary and ternary aqueous solution of 2-amino-2-methyl-1-propanol (AMP) was investigated A general correlation function in terms of temperature was used for each parameter so that the model can be applied to predict the solubilit
TL;DR: In this article, a generalization of the NRTL-QSPR model to the non-random two-liquid (NRTL) and universal quasi-chemical (UNIQUAC) model was proposed.
TL;DR: In this article, the authors measured liquid−liquid equilibria for nine binary systems containing 1-alkyl-3-methylimidazolium hexafluorophosphates with alcohols in the following temperature ranges: BMIM PF6 with 1-propanol or 1-butanol or 1 -pentanol.
Abstract: Liquid−liquid equilibria were measured for nine binary systems containing 1-alkyl-3-methylimidazolium hexafluorophosphates with alcohols in the following temperature ranges: BMIM PF6 with 1-propanol or 1-butanol or 1-pentanol and HMIM PF6 with 1-butanol or 1-pentanol from (278.15 to 343.15) K; HMIM PF6 with 1-propanol from (278.15 to 328.15) K; and OMIM PF6 with 1-propanol or 1-butanol or 1-pentanol from (278.15 to 307.15) K, (278.15 to 323.15) K, and (278.15 to 333.15) K, respectively. The equation results were satisfactorily correlated by the NRTL and UNIQUAC models.
TL;DR: In this paper, the universal quasichemical activity coefficient (UNIQUAC) and the non-random two liquids equation (NRTL) were used to predict the phase equilibrium in the system using the interaction parameters determined from experimental data.
TL;DR: In this paper, the ternary system ethanol+2-butanone+2,2,4-trimethylpentane (isooctane) and its constituent binary systems were determined.
TL;DR: The reliability of the experimental tie-line data was ascertained by applying the Othmer−Tobias correlation as mentioned in this paper, which correlated with the NRTL and UNIQUAC models successfully.
Abstract: Liquid−liquid equilibria of the ternary system water + acetic acid + methyl tert-butyl ether were studied from 293.15 K to 318.15 K at atmospheric pressure. Distribution coefficients and separation factors were evaluated for the immiscibility region. The reliability of the experimental tie-line data was ascertained by applying the Othmer−Tobias correlation. The experimental results were also correlated with the NRTL and UNIQUAC models successfully.
TL;DR: In this article, the UNIQUAC activity coefficient model was used to calculate the distribution coefficients and selectivity factors of methanol and ethanol for the extraction of oleic acid from (corn oil + oleric acid) mixtures.
Abstract: Liquid−liquid equilibrium data for the systems {corn oil + oleic acid + methanol} and {corn oil + oleic acid + ethanol} at (303.15 and 313.15) K are reported. The experimental liquid−liquid data were correlated using the UNIQUAC activity coefficient model, and the relevant parameters are presented. The experimental and calculated compositions of the equilibrium phases were compared, and the relative mean square deviations (rmsd) are reported. The results indicate applicability of the UNIQUAC activity coefficients model for liquid−liquid equilibrium calculations of the studied mixtures. The distribution coefficients and the selectivity factors of methanol and ethanol for the extraction of oleic acid from (corn oil + oleic acid) mixtures were calculated and presented. From our experimental and calculated results, we conclude that increasing the temperature causes an increase in the distribution coefficient but a decrease in the selectivity factor; therefore, considering economic and practical aspects, room ...
TL;DR: In this article, phase diagrams of ternary and quaternary systems containing n-hexane (C6H14), toluene (C7H8), m-xylene (C8H10), propanol (C3H8O), sulfolane(C4H8SO2), and water (H2O) are presented.
TL;DR: The molar excess enthalpies (H m E ) for 2-{(2 aminoethyl)amino}ethanol (AEEA), 3-amino-1-propanol (AP), 2-(methylamino)ethylanol (MAE), 1-aminosinamide (MIPA), and N-N-dimethylethanolamine (DMEA) in water are reported at three different T = (298.15, 313.15 and 323.15) K and over the entire range of mole
TL;DR: In this article, the ternary VLE data at 333.15 K and the excess molar volumes (V E) and deviations in molar refractivity (ΔR) were determined from measured densities and refractive indices.
Abstract: Isothermal vapor−liquid equilibrium (VLE) data at 333.15 K are reported for the binary systems of di-n-butyl ether (DBE) + ethanol, ethanol + benzene, DBE + benzene, and the ternary system of DBE + ethanol + benzene by using headspace gas chromatography. The experimental binary VLE data were correlated with common G E model equations. The ternary VLE data were correlated also with Wilson, NRTL, and UNIQUAC models. Additionally the excess molar volumes (V E) and deviations in molar refractivity (ΔR) at 298.15 K for the constituent binary and ternary systems of DBE + ethanol + benzene were determined from measured densities and refractive indices. The experimental V E and ΔR were correlated with Redlich−Kister or Cibulka equation for the binary and ternary systems, respectively. The ternary V E and ΔR were also compared with the estimated values from the binary contribution models of of Tsao−Smith, Kohler, Rastogi, and Radojkovic.
TL;DR: In this article, the tie-line data were correlated by means of the UNIQUAC equation, and compared with results predicted by the UNIFAC method, and a comparison of the extracting capabilities of the solvents was made with respect to distribution coefficients, separation factors, and solvent free selectivity bases.
TL;DR: In this paper, the reliability of the experimental tie-line data was determined through the Bachman plots, and the experimental data were also compared with the values correlated by the NRTL and UNIQUAC models.
TL;DR: Isothermal vapor−liquid equilibria (VLE) and excess molar enthalpies (H E) at 323.15 K were measured for the binary mixtures of dimethyl ether (DME) with C1 to C4 alkan-1-ols as discussed by the authors.
Abstract: Isothermal vapor−liquid equilibria (VLE) and excess molar enthalpies (H E) at 323.15 K were measured for the binary mixtures of dimethyl ether (DME) with C1 to C4 alkan-1-ols. The measured VLE and H E data were correlated well with G E model equations and Redlich−Kister polynomial, respectively. Additionally liquid−liquid equilibrium (LLE) for the ternary system of DME + methanol + water was determined at 313.15 K. The measured LLE data were compared with the correlated values by using NRTL and UNIQUAC models, and they showed good agreements.
TL;DR: In this paper, a new thermodynamic model for predicting phase equilibriums of crude oils is proposed, which can be used to describe the systems which contain paraffin, naphthene and aromatic fractions.