首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 46 毫秒
1.
Vapor-liquid equilibrium (VLE) data at 50, 75, and 94 kPa have been determined for the binary system ethyl 1,1-dimethylethyl ether + 2-propanol, in the temperature range 323-344 K. The measurements were made in an equilibrium still with circulation of both the vapor and liquid phases. Excess volumes have been also determined from density measurements at 298.15 K. The system exhibits positive deviation from ideal behavior and azeotropic behavior in the range of experimental pressures. The excess volume of the system is negative over the whole mole fraction range. The activity coefficients and boiling points of the solutions were well correlated with the mole fraction by the Wohl, Wilson, UNIQUAC, NRTL equations and predicted by the UNIFAC group contribution method. Excess volume data were correlated using the Redlich-Kister expansion.  相似文献   

2.
Abstract

Vapor-liquid equilibrium at 94kPa has been determined for the binary systems oxolane (THF) + vinyl acetate, oxolane + ethyl 1,1-dimethylethyl ether (ETBE) and vinyl acetate + ethyl 1,1-dimethylethyl ether. The three systems present slight to moderate positive deviations from ideal behavior and, to a first approximation, can be considered to behave like regular solutions. An azeotrope is present in the system vinyl acetate + ETBE that boils at 340.40 K and contains 49.8% mol vinyl acetate. The activity coefficients of the systems were correlated reasonable well with its composition by the Wohl, Wilson, UNIQUAC and NRTL models. The boiling points of the binary systems were correlated with the Wisniak-Tamir equation.  相似文献   

3.
Abstract

Pure-component vapor pressure of ethyl 1,1-dimethylethyl ether and vapor-liquid equilibrium for the binary systems of ETBE with hexane and with heptane have been measured at 94kPa. Both systems deviate slightly from ideal behavior, can be described as regular solutions and do no present an azeotrope. The activity coefficients and boiling points of the solutions were correlated with its composition by the Redlich-Kister, Wohl, Wilson, UNIQUAC, NRTL, and Wisniak-Tamir equations.  相似文献   

4.
Abstract

Consistent vapor-liquid equilibrium has been determined for the binary systems 1-hexene + ethyl 1,1-dimethylethyl ether (ETBE) and ethyl 1,1-dimethylethyl ether + cyclohexene at 94.00 kPa. The two systems present slight positive deviations from ideal behavior, can be considered to behave like regular solutions and do not present azeotropic behavior. Pure component vapor pressures are also reported for 1-hexene and cyclohexene. The phase equilibrium of the systems was correlated well by the Wilson, UNIQUAC, and NRTL models and reasonably predicted by the UNIFAC group contribution method. The boiling points of the binary systems were correlated with the Wisniak-Tamir equation.  相似文献   

5.
Abstract

Consistent vapor-liquid equilibria for the binary systems of ETBE with benzene and cyclohexane at 94.00 kPa have been measured. Both systems show slightly positive deviation from ideal behavior and do no present azeotropic behavior. The activity coefficients and boiling points of the solutions were correlated with its mole fractions by the Redlich-Kister, Wohl, Wilson, UNIQUAC, NRTL, and Wisniak -Tamir equations. The data were also compared with UNIFAC predictions.  相似文献   

6.
Abstract

Consistent vapor-liquid equilibria data at 94.00 kPa have been determined for the ternary system ethyl 1,1-dimethylethyl ether + benzene + 2,2,4-trimethylpentane and for its constituent binary benzene + 2,2,4-trimethylpentane, in the temperature range 343 to 370 K. The systems exhibit slight positive deviations from ideal behavior and the system benzene + 2,2,4-trimethylpentane presents an azeotrope. The VLE data have been correlated with the mole fraction using the Redlich-Kister, Wilson, NRTL, UNIQUAC, and Tamir relations. These models, in addition to UNIFAC, allow good prediction of the VLE properties of the ternary system from those of the pertinent binary systems.  相似文献   

7.
Abstract

Consistent vapor-liquid equilibrium data at 94kPa have been determined for the ternary system methyl 1,1-dimethylethyl ether (MTBE) + benzene + toluene. The results indicate that the system deviates positively from ideality and that no azeotrope is present. The ternary activity coefficients of the system have been correlated with the composition using the Redlich-Kister, Wilson, NRTL, UNIQUAC, and UNIFAC, models. It is shown that most of the models allow a very good prediction of the phase equilibrium of the ternary system using the pertinent parameters of the binary systems. In addition, the Wisniak-Tamir relations were used for correlating bubble-point temperatures.  相似文献   

8.
这是为了较好地解决高效分离混合二甲苯所进行的一项基础性研究。准确测定了 0 .0 999MPa压力下邻、间、对二甲苯或乙苯 +异丙醇或叔丁醇八个体系的恒压汽液平衡数据 ,计算了该压力下八个体系中二组分的活度系数 ,作出了各体系的汽液平衡曲线及活度系数曲线 ,并讨论所呈现的规律。  相似文献   

9.
利用改进的沸点仪测定了顺酐-癸二酸二丁酯二元体系在413.15, 433.15和453.15 K下的等温气液平衡数据以及纯癸二酸二丁酯和顺酐的饱和蒸气压数据. 通过与文献值对比, 验证了此方法的可靠性. 同时, 将实验数据回归得到了纯癸二酸二丁酯和顺酐的Antoine常数. 利用NRTL方程进行了气液平衡数据的关联推算, 得到了顺酐-癸二酸二丁酯二元体系的NRTL模型参数. 利用UNIFAC基团贡献法对实验数据进行了预测, 其结果与实验值及运用NRTL方程拟合的结果吻合较好.  相似文献   

10.
Abstract

Vapor-liquid equilibria at 94.6 kPa, over the entire composition range were measured for three binary systems - butan-1-ol(1) + chlorobenzene(2), 2-methylpropan-1-ol(1) + chlorobenzene(2), 2-methylpropan-2-ol(1) + chlorobenzene(2)- using a Swietoslawski type ebulliometer. The composition (x 1) vs. temperature (T) data were found to be well represented by Wilson model.  相似文献   

11.
Abstract

This paper reports excess volumes, VE , and viscosity deviations, Δ\eta, for binary mixtures of 2-methyl-1-chloropropane with an isomer of butanol at the temperatures 298.15 K and 313.15 K. These properties were obtained from density and viscosity measurements. The results are correlated by means of a Redlich-Kister type equation, and interpreted in terms of molecular interactions. The systems show positive values of VE except in a short range of compositions for mixtures containing primary butanols (1-butanol at both temperatures and 2-methyl-1-propanol at 298.15 K), whereas Δ\eta presents negative values at both temperatures over the whole composition range.  相似文献   

12.
Abstract

Liquid-liquid equilibria, distribution coefficients, and selectivities of ternary systems of the type: (water + K + nitromethane), where Kis 1-propanol, acetone, or p-dioxane, have been determined at (303.15 ± 0.05) K, in order to evaluate the suitability of nitromethane for extracting preferentially the second components from their aqueous solutions. The line data were satisfactorily correlated by the Othmer and obias method, and the plait point coordinates for the three systems were estimated. The experimental data were compared with values calculated using the NRTL and UNIQUAC models, and with those predicted by the UNIFAC group contribution method. This last method predicts qualitative and quantitative behaviour which are in disagreement with experimental results, while the values calculated using the other two models are in agreement but only when the concentration of component K is low. The three ternary systems studied have distribution coefficients higher than unity, and high selectivities. Therefore, nitromethane could be considered as a potential solvent for the extraction of K from its aqueous solutions  相似文献   

13.
Excess molar volumes, change of refractive indexes, and deviation of dynamic viscosity of the 2-methoxyethanol + acetonitrile, 2-methoxyethanol + 1,2-dichloroethane, and acetonitrile + 1,2-dichloroethane binary systems and the excess molar volumes of 2-methoxyethanol + acetonitrile + 1,2-dichloroethane ternary system have been determined at 25°C and at atmospheric pressure, by measuring densities, refractive indexes, and viscosities over the entire range of composition. These derived data of binary and ternary mixtures were fitted to Redlich–Kister and Cibulka equations, respectively. An estimation of excess volumes is also evaluated using a modified Heller equation, which depends on the refractive indexes of the mixture. A comparison of the predictions by different methods with the experimental values of the physical properties has been made.  相似文献   

14.
Viscosities and densities have been measured for 1-propanol + n-heptane at 20, 25, 30, and 35°C and atmospheric pressure. Kinematic viscosities were determined using a capillary viscosimeter; densities were measured using vibrating-tube densimetry. The viscosity deviations were evaluated. Viscosity results were fitted to the equations of Grunberg–Nissan, McAllister, Auslander, and Teja. The experimental excess molar volumes were compared with the results obtained with the Nitta–Chao model.  相似文献   

15.
Binary excess molar volumes, V m E, have been evaluated from density measurements, using a vibrating tube densimeter over the entire composition range for binary liquid mixtures of ionic liquids 1-ethyl-3-methyl-imidazolium diethyleneglycol monomethylethersulphate [EMIM]+[CH3(OCH2CH2)2OSO3] or 1-butyl-3-methyl-imidazolium diethyleneglycol monomethylethersulphate [BMIM]+[CH3(OCH2CH2)2OSO3] or 1-methyl-3-octyl-imidazolium diethyleneglycol monomethylethersulphate [MOIM]+[CH3(OCH2CH2)2OSO3]+methanol and [EMIM]+[CH3(OCH2CH2)2OSO3]+water at 298.15, 303.15 and 313.15 K. The V m E values were found to be negative for all systems studied. The V m E results are explained in terms of intermolecular interactions and packing effects. The experimental data were fitted by the Redlich-Kister polynomial.  相似文献   

16.
测定了对二甲苯+环己烷及对二甲苯+二甲基亚砜体系(均为简单低共熔混合物)的固液平衡相图,计算出它们在313.15K的过量吉布斯自由能。结果表明两体系对理想溶液均产生正偏差。  相似文献   

17.
正已醇-邻、间、对二甲苯二元系固液相平衡   总被引:1,自引:0,他引:1  
Melting temperatures have been measured and the solid-liquid phase diagrams constructed for 1-hexanol+o-xylene, 1-hexanol+m-xylene and 1-hexanol+p-xylene. They are simple eutectic systems. Excess mole Gibbs free energies were calculated at 298.15K, showing larger positive deviations from ideal-solution behavior. The largest values of GmE are 711、 650 and 800 J•mol-1 for {o-C6H4(CH3)2+C6H13OH}、 {m-C6H4(CH3)2 + C6H13OH} and {p-C6H4(CH3)2+C6H13OH} respectively.  相似文献   

18.
Densities of the binary systems of dimethyl sulfoxide with ethyl acrylate, butyl acrylate, methyl methacrylate, and styrene have been measured as a function of the composition at 298.15 K and atmospheric pressure using an Anton Paar DMA 5000 oscillating U-tube densimeter. The calculated excess volumes were correlated with the Redlich–Kister equation and with a series of Legendre polynomials. The excess volumes are negative for the four binaries, probably as a result of the large dipole moment of DMSO, becoming smaller as the monomer becomes more branched or longer, and the dipole moment per monomer unit becomes larger.  相似文献   

19.
Densities of the binary systems of toluene with butyl methacrylate, allyl methacrylate, methacrylic acid, and vinyl acetate have been measured as a function of composition at 20, 30 and 40 °C at atmospheric pressure, using an Anton Paar DMA 5000 oscillating U-tube densimeter. The excess molar volumes are negative for the system toluene + butyl methacrylate and positive for the three other binaries, and become more so as the temperature increases from 20 to 40 °C. The system toluene + allyl methacrylate presents near ideal behavior. The apparent volumes were used to calculate values of the partial excess molar volumes at infinite dilution. The excess coefficient of thermal expansion is positive for the four binary systems. The calculated excess molar volumes were correlated with the Redlich–Kister equation and with a series of Legendre polynomials. An explanation of the results is given based by the FT-IR (ATR) and 13C NMR spectra of equimolar mixtures of the different systems.  相似文献   

20.
Refractive indices at 298.15 K and densities in the temperature interval 293.15 to 318.15 K were determined at atmospheric pressure over the whole composition range for the binary systems [Bmim][BF4]+(methanol, or 1,3-dichloropropane, or dimethyl carbonate). Due to the high viscosity of the samples, which would produce a wrong density if a classical vibrating-tube densimeter were used, a densimeter was employed that automatically corrects the data for the viscosity effect. Because at room temperature some [Bmim][BF4]+dimethyl carbonate mixtures showed partial immiscibility, liquid-liquid equilibrium was determined for this system. Excess molar volumes and deviations of refractive index from linear mixing behavior were calculated from the experimental data. An erratum to this article can be found at  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号