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1.
《The Journal of chemical thermodynamics》2007,39(6):893-905
In this work, new (vapor + liquid) equilibrium data for the (N2 + n-heptane) system were experimentally measured over a wide temperature range from (313.6 to 523.7) K and pressures up to 50 MPa. A static-analytic apparatus with visual sapphire windows and pneumatic capillary samplers was used in the experimental measurements. Equilibrium phase compositions and (vapor + liquid) equilibrium ratios are reported. The new results were compared with those reported by other authors. The comparison showed that the pressure–composition data reported in this work are less scattered than those determined by others. Hence, the results demonstrate the reliability of the experimental apparatus at high temperatures and pressures. The experimental data were represented with the PR and PC-SAFT equations of state by using one-fluid mixing rules and a single temperature independent interaction parameter. Results of the representation showed that the PC-SAFT equation was superior to the PR equation in correlating the experimental data of the (N2 + n-heptane) system. 相似文献
2.
The bromide minerals solubility in the mixed system (m1NaBr + m2MgBr2)(aq) have been investigated at T = 323.15 K by the physico-chemical analysis method. The equilibrium crystallization of NaBr·2H2O(cr), NaBr(cr), and MgBr2·6H2O(cr) has been established. The solubility-measurements results obtained have been combined with all other experimental equilibrium solubility data available in literature at T = (273.15 and 298.15) K to construct a chemical model that calculates (solid + liquid) equilibria in the mixed system (m1NaBr + m2MgBr2)(aq). The solubility modeling approach based on fundamental Pitzer specific interaction equations is employed. The model gives a very good agreement with bromide salts equilibrium solubility data. Temperature extrapolation of the mixed system model provides reasonable mineral solubility at high temperature (up to 100 °C). This model expands the previously published temperature variable sodium–potassium–bromide and potassium–magnesium–bromide models by evaluating sodium–magnesium mixing parameters. The resulting model for quaternary system (Na + K + Mg + Br + H2O) is validated by comparing solubility predictions with those given in literature, and not used in the parameterization process. Limitations of the mixed solution models due to data insufficiencies at high temperature are discussed. 相似文献
3.
M. Mohsen-Nia E. Nekoei F.S. Mohammad Doulabi 《The Journal of chemical thermodynamics》2008,40(2):330-333
(Liquid + liquid) equilibrium (LLE) data for the ternary mixtures of (methanol + aniline + n-octane) and (methanol + aniline + n-dodecane) at T = 298.15 K and ambient pressure are reported. The compositions of liquid phases at equilibrium were determined and the results were correlated with the UNIQUAC and NRTL activity coefficient models. The partition coefficients and the selectivity factor of methanol for the extraction of aniline from the (aniline + n-octane or n-dodecane) mixtures are calculated and compared. Based on these comparisons, the efficiency of methanol for the extraction of aniline from (aniline + n-dodecane) mixtures is higher than that for the extraction of aniline from (aniline + n-octane) mixtures. The phase diagrams for the ternary mixtures including both the experimental and correlated tie lines are presented. From the phase diagrams and the selectivity factors, it is concluded that methanol may be used as a suitable solvent in extraction of aniline from (aniline + n-octane or n-dodecane) mixtures. 相似文献
4.
《The Journal of chemical thermodynamics》2007,39(2):316-321
Isopiestic measurements have been carried out at the temperature 298.15 K for two saturated aqueous solutions: {H2O + BaCl2(sat) + NaCl + NH4Cl} saturated with barium chloride and {H2O + BaCl2(sat) + mannitol(sat) + NaCl + NH4Cl} saturated with barium chloride and mannitol. Taking sodium chloride (aq) as reference solutions, osmotic coefficients of the aqueous solutions were determined. The experimental results are well represented by the ideal-like solution model. 相似文献
5.
The experimental (liquid + liquid) equilibrium (LLE) properties for two ternary systems containing (N-formylmorpholine + benzene + n-hexane), (sulfolane + benzene + n-hexane) and a quaternary mixed solvent system (sulfolane + N-formylmorpholine + benzene + n-hexane) were measured at temperature ranging from (298.15 to 318.15) K and at an atmospheric pressure. The experimental distribution coefficients and selectivity factors are presented to evaluate the efficiency of the solvents for extraction of benzene from n-hexane. The LLE results obtained indicate that increasing temperature decreases selectivity for all solvents. The LLE results for the systems studied were used to obtain binary interaction parameters in the UNIQUAC model by minimizing the root mean square deviations (RMSD) between the experimental and calculated results. Using the interaction parameters obtained, the phase equilibria in the systems were calculated and plotted. The calculated compositions based on the UNIQUAC model were found to be in good agreement with the experimental values. The result of the RMSD obtained by comparing the calculated and experimental two-phase compositions is 0.0163 for (N-formylmorpholine + benzene + n-hexane) system and is 0.0120 for (sulfolane + benzene + n-hexane) system. 相似文献
6.
Kamel Khimeche Abdallah Dahmani Jacques Jose 《The Journal of chemical thermodynamics》2008,40(5):777-781
The vapour pressures of liquid (3-diethylaminopropylamine (3-DEPA) + n-heptane) mixtures were measured by a static method between T = (303.15 and 343.15) K at 10 K intervals. The molar excess enthalpies HE at T = 303.15 K were measured for the systems {3-DEPA + CnH2n+2 (n = 6, 7, 12)}. The molar excess Gibbs free energies GE were obtained with Barker’s method and fitted to the Redlich–Kister equation. The Wilson equation was also used. Deviations between experimental and predicted GE and HE, by using group contribution UNIFAC (Gmehling version) model, were evaluated. 相似文献
7.
《The Journal of chemical thermodynamics》2007,39(2):218-224
Density, ρ, speed of sound, u, and refractive index, nD, at 298.15 K and atmospheric pressure have been measured over the entire composition range for (toluene + methyl acetate + butyl acetate) and (toluene + methyl acetate + methyl heptanoate) systems. Excess molar volumes, VE, isentropic compressibility, κs, isentropic compressibility deviations, Δκs, and changes of refractive index on mixing, ΔnD, for the above systems, have been calculated from experimental data and fitted to Cibulka, Singh et al., and Nagata and Sakura equations, standard deviations from the regression lines are shown. Geometrical solution models, Tsao and Smith, Kholer, Jacob and Fitzner, Rastogi et al. were also applied to predict ternary properties from binary contributions. 相似文献
8.
Sunghyun Jang Moon Sam Shin Yongjin Lee Hwayong Kim 《The Journal of chemical thermodynamics》2009,41(1):51-55
2-Propoxyethanol (C3E1) is one of nonionic surfactants which are a particularly interesting class of substances due to both inter-molecular and intra-molecular association. Binary (vapor + liquid) equilibrium data were measured for {2-propoxyethanol (C3E1) + n-hexane} and {2-propoxyethanol (C3E1) + n-heptane} systems at temperatures ranging from (303.15 to 323.15) K. A static apparatus was used in this study. The experimental data were correlated well with a lattice fluid equation of state that combines the multi-fluid non-random lattice fluid model with Veytsman statistics for (intra + inter)-molecular association. 相似文献
9.
《The Journal of chemical thermodynamics》2006,38(11):1285-1291
Experimental (liquid + liquid) equilibrium data were obtained for the extraction of toluene from n-decane by mixed-solvents (ethanol + water) and (ethanol + methanol) at three temperatures (298.15, 303.15, and 313.15) K and ambient pressure.The measured tie-line data for two quaternary mixtures of {(ethanol + water) + toluene + n-decane} and {(ethanol + methanol) + toluene + n-decane} are presented. The experimental quaternary (liquid + liquid) equilibrium data have been correlated using the NRTL activity coefficient model to obtain the binary interaction parameters of these components. The NRTL models predict the equilibrium compositions of the quaternary mixtures with small deviations. The partition coefficients and the selectivity factor of the mixed-solvents used were calculated and presented. From our experimental and calculated results, we conclude that for the extraction of toluene from n-decane mixtures the mixed-solvent (ethanol + methanol) has a higher selectivity factor than the other mixed-solvent at the three temperatures studied. 相似文献
10.
Zhiyong Li Yuanchao Pei Li Liu Jianji Wang 《The Journal of chemical thermodynamics》2010,42(7):932-937
In the present work, (liquid + liquid) equilibrium data have been determined experimentally for aqueous two-phase systems formed by the imidazolium ionic liquids of [Cnmim][CH3COO] (n = 4, 6, 8) and inorganic salts of K3PO4, K2HPO4, and K2CO3 at T = 298.15 K. Combined with available data in the literature, the effect of alkyl chain length of cations, type of anions of the ionic liquids, and nature of the inorganic salts were examined on the binodal curves of the systems. Then the binodal curves were fitted to a four-parameter empirical equation, and the tie-lines were described by the Othmer–Tobias and Bancroft equations. In addition, the extraction capacity of the {[Cnmim][CH3COO] (n = 4, 6, 8) + K3PO4} aqueous two-phase systems was evaluated through their application to the extraction of l-tryptophan. The high extraction efficiency suggests that these aqueous two-phase systems are feasible to be used in the extraction and separation process. 相似文献
11.
(Solid + liquid) equilibria (SLE) prediction are an important phase equilibria property for ionic liquid (IL) mixtures especially when the IL exists as a solid. In this work, the SLE for the binary systems of (IL + thiophene) consisting of the ILs: n-butyl-4-methylpyridinium tosylate [BM4Py][TOS], n-butyl-3-methylpyridinium tosylate [BM3Py][TOS], n-hexyl-3-methylpyridinium tosylate [HM3Py][TOS], and 1,4-dimethylpyridinium tosylate [M1,4Py][TOS] are predicted using the quantum chemical based COSMO-RS (COnductor like Screening MOdel for Real Solvents) model. Initially, benchmarking studies are performed on binary mixtures which are known beforehand. The values of the predicted solubility are then compared with the experimental results by calculating the root mean square error (RMSE). The SLE predictions of the solubility of pyrene and dibenzothiophene in five different solvents were carried out giving an average RMSE of 4%. Further the applicability of COSMO-RS to binary systems consisting of (ionic liquid + alcohol) mixtures and (ionic liquid + hydrocarbons) are predicted. The ionic liquids concerned are n-butyl-3-methylpyridinium tosylate [BM3Py][TOS] while the alcohols and hydrocarbons are 1-butanol, 1-hexanol, 1-octanol, 1-decanol, and benzene, toluene, ethylbenzene, n-propylbenzene respectively. The experimental data for the ionic liquid [BM4Py][TOS] with thiophene gave the smallest deviation of 10.2%. The overall RMSE for IL–thiophene, IL–alcohol, and IL–hydrocarbons were 15%, 17.2% and 12.9% respectively. Thus the predicted solubility values were found to be in reasonable agreement with the experimental values. 相似文献
12.
《The Journal of chemical thermodynamics》2006,38(4):484-489
(Liquid + liquid) equilibrium tie-lines were measured for one ternary system {x1H2O + x2(CH3)2CHOH + (1 − x1 − x2)CH3C(CH3)2OCH3} and one quaternary system {x1H2O + x2(CH3)2CHOH + x3CH3C(CH3)2OCH3 + (1 − x1 − x2 − x3)(CH3)2CHOCH(CH3)2} at T = 298.15 K and P∘ = 101.3 kPa. The experimental (liquid + liquid) equilibrium results were satisfactorily correlated by modified and extended UNIQUAC models both with ternary and quaternary parameters in addition to binary ones. 相似文献
13.
《The Journal of chemical thermodynamics》2006,38(6):696-700
(Liquid + liquid) equilibrium (LLE) data for the (water + butyric acid + dodecanol) ternary system have been determined experimentally at T = (298.2, 308.2 and 318.2) K. Complete phase diagrams were obtained by determining binodal curves and tie lines. The reliability of the experimental tie lines was confirmed by using the Othmer–Tobias correlation. The UNIFAC method was used to predict the phase equilibrium in the ternary system using the interaction parameters determined from experimental data of CH3, CH2, COOH, OH and H2O functional groups. Distribution coefficients and separation factors were evaluated for the immiscibility region. 相似文献
14.
The solubility of the binary system (LiNO3 + H2O) from T = 273.15 K to T = 333.15 K and solubility isotherms of the ternary system (LiCl + LiNO3 + H2O) were elaborately measured at T = 273.15 K and T = 323.15 K. These solubility data, as well as water activities in the binary systems from the literature, were treated by an empirically modified BET model. The isotherms of the ternary system (LiCl + LiNO3 + H2O) were reproduced and a complete phase diagram of the ternary system in the temperature range from 273.15 K to 323.15 K predicted. It is shown that the solubility data for the binary system (LiNO3 + H2O) measured in this work are slightly different from the literature data. Simulated results showed that the saturated salt solution of (2.8LiCl + LiNO3) is in equilibrium with the stable solid phase LiNO3(s) over the temperature range from 283.15 K to 323.15 K, other than the solid phases LiNO3 · 3H2O(s) and LiClH2O(s) as reported by Iyoki et al. [S. Iwasaki, Y. Kuriyama. T. Uemura, J. Chem. Eng. Data 38 (1993) 396–398]. 相似文献
15.
Estela Lladosa Juan B. Montón MaCruz Burguet Javier de la Torre 《The Journal of chemical thermodynamics》2008,40(5):867-873
Isobaric (vapour + liquid + liquid) equilibria were measured for the (di-n-propyl ether + n-propyl alcohol + water) and (diisopropyl ether + isopropyl alcohol + water) system at 100 kPa.The apparatus used for the determination of (vapour + liquid + liquid) equilibrium data was an all-glass dynamic recirculating still with an ultrasonic homogenizer couple to the boiling flask.The experimental data demonstrated the existence of a heterogeneous ternary azeotrope for both ternary systems. The (vapour + liquid + liquid) equilibria data were found to be thermodynamically consistent for both systems.The experimental data were compared with the estimation using UNIQUAC and NRTL models and the prediction of UNIFAC model. 相似文献
16.
《The Journal of chemical thermodynamics》2006,38(8):1062-1071
Density ρ, viscosity η, and refractive index nD, values for (tetradecane + benzene, + toluene, + chlorobenzene, + bromobenzene, + anisole) binary mixtures over the entire range of mole fraction have been measured at temperatures (298.15, 303.15, and 308.15) K at atmospheric pressure. The speed of sound u has been measured at T = 298.15 K only. Using these data, excess molar volume VE, deviations in viscosity Δη, Lorentz–Lorenz molar refraction ΔR, speed of sound Δu, and isentropic compressibility Δks have been calculated. These results have been fitted to the Redlich and Kister polynomial equation to estimate the binary interaction parameters and standard deviations. Excess molar volumes have exhibited both positive and negative trends in many mixtures, depending upon the nature of the second component of the mixture. For the (tetradecane + chlorobenzene) binary mixture, an incipient inversion has been observed. Calculated thermodynamic quantities have been discussed in terms of intermolecular interactions between mixing components. 相似文献
17.
《Fluid Phase Equilibria》2006,239(1):1-7
Liquid–liquid equilibrium (LLE) data were determined for the quaternary systems of {(water + methanol or ethanol) + m-xylene + n-dodecane} at three temperatures 298.15, 303.15 and 313.15 K and atmospheric pressure. The composition of liquid phases at equilibrium was determined by gas–liquid chromatography and the results were correlated with the UNIQUAC and NRTL activity coefficient models. The partition coefficients and the selectivity factor of the solvent are calculated and compared. The phase diagrams for the quaternary systems including both the experimental and correlated tie lines are presented. 相似文献
18.
Dewen Zeng Wenfang Xu Wolfgang Voigt Xia Yin 《The Journal of chemical thermodynamics》2008,40(7):1157-1165
Solubility isotherms of the ternary system (LiCl + CaCl2 + H2O) were elaborately determined at T = (283.15 and 323.15) K. Several thermodynamic models were applied to represent the thermodynamic properties of this system. By comparing the predicted and experimental water activities in the ternary system, an empirical modified BET model was selected to represent the thermodynamic properties of this system. The solubility data determined in this work at T = (283.15 and 323.15) K, as well as those from the literature at other temperatures, were used for the model parameterization. A complete phase diagram of the ternary system was predicted over the temperature range from (273.15 to 323.15) K. Subsequently, the Gibbs free energy of formation of the solid phases CaCl2 · 4 H2O(s), CaCl2 · 2 H2O(s), LiCl · 2H2O(s), and LiCl · CaCl2 · 5H2O(s) was estimated and compared with the literature data. 相似文献
19.
The apparent molar volumes and isentropic compressibility of glycine, l-alanine and l-serine in water and in aqueous solutions of (0.500 and 1.00) mol · kg?1 di-ammonium hydrogen citrate {(NH4)2HCit} and those of (NH4)2HCit in water have been obtained over the (288.15 to 313.15) K temperature range at 5 K intervals at atmospheric pressure from measurements of density and ultrasonic velocity. The apparent molar volume and isentropic compressibility values at infinite dilution of the investigated amino acids have been obtained and their variations with temperature and their transfer properties from water to aqueous solutions of (NH4)2HCit have also been obtained. The results have been interpreted in terms of the hydration of the amino acids. In the second part of this work, water activity measurements by the isopiestic method have been carried out on the aqueous solutions of {glycine + (NH4)2HCit}, {alanine + (NH4)2HCit}, and {serine + (NH4)2HCit} at T = 298.15 K at atmospheric pressure. From these measurements, values of vapour pressure, osmotic coefficient, activity coefficient and Gibbs free energy were obtained. The effect of the type of amino acids on the (vapour + liquid) equilibrium of the systems investigated has been studied. The experimental water activities have been correlated successfully with the segment-based local composition Wilson model. Furthermore, the thermodynamic behaviour of the ternary solutions investigated has been studied by using the semi-ideal hydration model and the linear concentration relations have been tested by comparing with the isopiestic measurements for the studied systems at T = 298.15 K. 相似文献
20.
Phase diagram and (liquid + liquid) equilibrium (LLE) results for {NaClO4 + polyethylene glycol 4000 (PEG 4000) + H2O} have been determined experimentally at T = (288.15, 298.15, and 308.15) K. The Chen-NRTL, modified Wilson and UNIQUAC models were used to correlate the values for the experimental tie-lines. The results show that the quality of fitting is better with the modified Wilson model. 相似文献