Isobaric vapor liquid equilibrium in binary mixtures of α-pinene,limonene and 1, 8-cineole

Isobaric vapor liquid equilibrium at atmospheric pressure has been determined for binary mixtures of (–) α-pinene, (+)-limonene and 1, 8-cineole. The Margules and Var Laar equations as well as the models proposed by Wilson, by Renon and Prausnitz (NRTL) and by Abrams and Prausnitz (UNIQUAC) were used to correlate the experimental data. The corresponding parameters for two binaries are reported here.     

Isobaric vapor—liquid equilibrium in binary mixtures of m- and p-xylenes with cyclohexene and cyclohexanone

The vapor-liquid equilibrium data of the binary mixtures of m- and p-xylenes with cyclohexene and cyclohexanone are determined at P = 40 and 98.67 kPa. The systems show a nearly ideal behavior with no remarkable difference in the activity coefficients of m- and p-xylenes. The experimental data are correlated by the Wilson expression.     

The vapour—liquid equilibria of the binary,ternary and quaternary systems formed by acetone,methanol, propan-2-ol,and water

The vapour-liquid equilibrium data of the binary, ternary and quaternary systems that may be formed by combination of the components acetone, methanol, propan-2-ol and water, have been determined at 760 mmHg by means of an equilibrium still based on the principle of circulation of both phases. The binary data have been correlated by means of the Margules and of the Wilson equation. The data of the ternary and quaternary systems have been predicted by these equations. The results of both equations are discussed and compared.     

Isobaric vapour-liquid equilibrium for the binary mixtures of 1-bromobutane with isomeric butanols at 40.0 and 101.3 kpa

A dynamic recirculating still was employed to measure isobaric vapour-liquid equilibrium at 40.0 and 101.3 kPa for the binary systems 1-bromobutane and each of the isomers of butanol. All mixtures show azeotropes at both pressures. The experimental VLE data are thermodynamically consistent and were correlated using Margules, Van Laar, Wilson, NRTL and UNIQUAC equations.     

Isobaric vapor–liquid equilibria for mixtures of tetrahydrofuran, 2-propanol, and 2,2,4-trimethylpentane at 101.3 kPa

Vapor–liquid equilibrium (VLE) at 101.3 kPa have been determined for a ternary system (tetrahydofuran + 2-propanol + 2,2,4-trimethylpentane) and its constituent binary systems (tetrahydrofuran + 2-propanol, tetrahydrofuran + 2,2,4-trimethylpentane, and 2-propanol + 2,2,4-trimethylpentane). The activity coefficients of liquid mixtures were calculated from the modified Raoult's law. Thermodynamic consistency tests were performed for all VLE data. The VLE data of the binary mixtures and ternary mixtures were correlated using the Margules, Wilson, NRTL, and UNIQUAC activity-coefficient models. The models with their best-fitted interaction parameters of the binary systems were used to predict the ternary vapor–liquid equilibrium. All VLE data are also used to calculate the reduced excess molar Gibbs free energy g^E/RT and the deviations in the boiling point ΔT. The calculated quantities of g^E/RT and ΔT were fitted to variable-degree polynomials in terms of liquid composition.     

Vapor liquid equilibrium data for alcohol n-Amylamine binary systems at 333.15 K. Reduction of the experimental data by a novel model-free method

Vapor liquid equilibrium measurements for the binary systems of n-amylamine with methanol, ethanol and 1-propanol at 333.15 K are reported. The measurements were made in a static equilibrium cell of the Van Ness type and the experimental data were reduced using a model-free method. This model-free method is an adaptation of the method of Mixon et al. in which a material balance is introduced to correct for the mols of the gas phase. Second virial coefficients of n-amylamine and cross second virial coefficients for the binary systems were measured in this work and parameters for the Tsonoupolos correlation are reported.     

Representation of vapor–liquid and liquid–liquid equilibria for binary systems containing polymers: Applicability of an extended flory–huggins equation

For some binary systems, an extended Flory–Huggins equation is applicable to both vaporliquid equilibria (VLE) and liquid–liquid equilibria (LLE) using the same adjustable parameters. New LLE and VLE data are reported for polystyrene (PS) (MW = 100,000)/cyclohexane and for poly(ethylene glycol) (PEG) (MW = 8,000)/water. Experimental results for the PS/cyclohexane system agree well with the semiempirical model, whereas those for PEG/water do not, probably because, for PEG/water, the temperature range of the VLE data is about 55°C lower than that of the LLE data. Excellent fits were obtained for our previously published experimental results for PS/cyclohexane (upper critical solution temperature, UCST), PS/ethyl acetate (lower critical solution temperature, LCST), PS/tert-butyl acetate and PS/methyl acetate (both UCST and LCST), and PEG/water (closed-loop). The semiempirical model also fits well with new data obtained for the polymer blend PS/poly(vinyl methyl ether). © 1993 John Wiley & Sons, Inc.     

煤炭直接液化体系高温高压气液相平衡研究进展及模型选择

笔者从气液相平衡基础理论展开并综述了高温高压相平衡计算研究进展，介绍了状态方程法、混合模型法、超额Gibbs自由能-状态方程模型法，并重点介绍了超额Gibbs自由能-状态方程模型法的思路及应用特点。针对煤炭直接液化物系高温、高压、强不对称、强极性、完全非理想体系等特点，与结合传统混合规则的状态方程法及混合模型法相比较，采用超额Gibbs自由能-状态方程模型法能够在更大范围内准确计算和预测煤液化气液相平衡。     

乙酸异戊酯+异戊醇和乙酸异戊酯+正己醇体系汽液平衡

在50.00和101.33 kPa下,采用改进的Rose汽液平衡釜测量乙酸异戊酯+异戊醇和乙酸异戊酯+正己醇体系的汽液平衡数据。乙酸异戊酯+异戊醇在50.00 kPa下形成最低共沸物。使用Herington法对汽液平衡数据进行热力学一次性检验,结果表明测得的汽液平衡数据符合热力学一致性。对实验数据使用NRTL、Wilson和UNIQUAC活度系数模型进行关联,回归获得相应的二元交互参数,模型计算的温度和组成与实验值相比均方差小于0.20 K和0.0050,表明3种模型的拟合结果与实验数据吻合较好。通过Wilson模型预测乙酸异戊酯+异戊醇体系在98.4 kPa时共沸点消失。为化工数据库增添了内容,为乙酸异戊酯体系的工程设计和进一步深入研究奠定了基础。     

High pressure phase equilibria in the carbon dioxide - n-Hexadecane and carbon dioxide — water systems

Phase equilibria in the carbon dioxide - n-hexadecane and carbon dioxide – water systems have been measured at temperatures between 314 K and 353 K and pressures between 8.53 and 16.12 MPa. The results have been correlated using two cubic equations of state and also compared with measurements reported in the literature.     

Liquid—liquid equilibria of ternary ETBE-ETOH-H2O and quaternary ETBE-ETOH-H2O-TBA mixtures

Liquid-liquid equilibria of ETBE-EtOH-H₂O mixtures are measured at 15,25 and 35°C. UNIQUAC and NRTL equations are fitted to the experimental data using ASPEN PLUS. Both the experimental and correlated values of the equilibrium compositions are compared with the values predicted by UNIFAC method. The same procedure is extended to quaternary ETBE-EtOH-H₂O-TBA system at low TBA concentration.     

Isobaric vapor-liquid equilibrium and liquid-phase enthalpy of mixing data for the binary mixtures of m- or p-Xylene with cyclohexanol

Isobaric vapor-liquid equilibrium data and liquid-phase enthalpy of mixing are investigated for the binary mixtures of m- or p-xylene with cyclohexanol. Allowance for self-association of the cyclic alcohol is made when assessing the thermodynamic consistency of the experimental data. Activity coefficients are correlated to mole fractions through the Wilson Equation, the parameters of which are obtained by the method of maximum likelihood and compared with the ones given by the conventional unweighted least-squares procedure.     

UNIFAC模型与PRSV方程相结合预测二元及三元系统汽液相平衡

采用Ｗｏｎｇ和Ｓａｎｄｌｅｒ混合规则，将ＰＲＳＶ立方型状态方程与ＵＮＩＦＡＣ活度系数模型相结合，给出一种预测混合物相平衡热力学性质的方法，并用５４个二元体系和９个三元体系的实验数据做了检验，结果表明，该法可以较好地预测二元及三元体系的汽液相平衡。     

Prediction and experimental determination of vapour-liquid equilibria for benzene + Cyclohexane + 1-Butanol mixtures at 101.325 kPa

This article reports experimentally determined vapour-liquid equilibrium data for benzene + cyclohexane + 1-butanol mixtures at constant pressure of 101.325 kPa, and compares the results with those predicted by the group contribution methods ASOG-KT and UNIFAC and by the Wilson, NRTL and UNIQUAC models after calculation of their adjustable parameters from the corresponding binary systems.     

PhreeqC modeling of Friedel's salt equilibria at 23±1 °C

A series of slurries containing Friedel's salt (3CaO·Al₂O₃·CaCl₂·10H₂O) in equilibrium with other solids that include Al(OH)₃, Ca(OH)₂, and 3CaO·Al₂O₃·6H₂O were produced at room temperature (23±1 °C). The liquid phases were analyzed for calcium, aluminum, and chlorine, and the speciation program PhreeqC was used to model the equilibria that were established between the solid and liquid phases. By matching closely, the experimentally determined solution parameters with those calculated using PhreeqC, important information concerning equilibria in the CaO-Al₂O₃-CaCl₂-H₂O system was obtained. For example, it was shown that the stable phase pair, Friedel's salt/3CaO·Al₂O₃·6H₂O, acts to buffer against rising chloride concentrations by acting as a chloride sink. PhreeqC calculations have estimated the solubility product of Friedel's salt to fall within the range −28.8<log K_sp<−27.6.     

一异丙醇胺-二异丙醇胺-水体系汽液平衡预测和推算

主要利用UNIFAC基团贡献法预测一异丙醇胺-二异丙醇胺-水三元体系的汽液平衡数据,同时又根据UNIQUAC二元模型参数推算上述三元体系的汽液平衡。预测值和推算值分别与实验测定的一异丙醇胺-二异丙醇胺-水三元体系在338、353、368 K下的恒温汽液平衡数据进行比较,三者符合良好,为该三元体系平衡数据的获得提供了又一途径。     

Measurement and prediction of high-pressure vapor-liquid equilibria for binary mixtures of carbon dioxide + n-octane, methanol, ethanol, and perfluorohexane

We report the measurement of high-pressure vapor-liquid equilibrium data for binary mixtures of carbon dioxide + n-octane, +methanol, and +ethanol systems at 313.14 K and carbon dioxide + perfluorohexane at 303.15-323.15 K. The experimental data were collected using a new simple apparatus for measuring high-pressure vapor-liquid equilibria and correlated using a modified SRK equation with the three-parameter conventional mixing rule proposed by Adachi and Sugie. The SAFT-VR equation of state has also been used to predict the phase behavior and found to be in good agreement with experimental data. For the carbon dioxide + methanol, carbon dioxide + ethanol and carbon dioxide + perfluorhexane systems simple Lorentz-Berthelot combining rules can be used to determine the cross interactions and predict the phase behavior. For the carbon dioxide + n-octane system cross interaction parameters fitted to experimental data are needed in order to capture the non-ideal phase behavior exhibited by this system.     

Phase equilibria of the propylene glycol/CO2 and propylene glycol/ethanol/CO2 systems

The high-pressure vapour–liquid phase equilibria (P–T–x–y) of the binary mixture propylene glycol/CO₂ have been experimentally investigated at temperatures of (398.2, 423.2 and 453.2) K over the pressure range from (2.5 to 55.0) MPa using a static-analytic method. Furthermore, the high-pressure vapour–liquid phase equilibria (P–T–x–y) of the ternary mixture propylene glycol/CO₂/ethanol at constant temperatures of (398.2, 423.2 and 453.2) K and at constant pressure of 15.0 MPa have been determined using a static-analytic method. Initial concentrations of components in propylene glycol (PG)/ethanol (EtOH) mixture vary from 10 up to 90 wt.%. In general, for binary system it was observed that the solubility of CO₂ in the heavy propylene glycol reach phase increases with increasing pressure at constant temperature. On the contrary, the composition of gaseous phase is not influenced by the pressure or the temperature. On average the solubility of PG in light phase of CO₂ amounts to 30 wt.%. The system behaviour at temperature of 398.2 K was investigated up to 70.0 MPa and a single-phase region was not observed. Above the pressure 60.0 MPa a single-phase region of the system was observed for the temperature of 423.2 K. For the temperature of 453.2 K the single-phase was observed above the pressure of 48.0 MPa. For ternary system it was observed that the composition of heavy phase is slightly influenced by the temperature when the mass fraction of EtOH in initial mixture is higher than 50 wt.%. If the mass fraction of PG in initial mixture is higher than 50 wt.%, the composition of heavy phase is not influenced by the temperature anymore. The composition of the PG, EtOH and CO₂ in light phase remains more or less unchanged and it is not influenced by the conditions.     

Measurement and correlation of vapor-liquid equilibria for hexamethyl disiloxane + vinyl acetate system at 101.3 kPa简

Vapor-liquid equilibrium data of hexamethyl disiloxane ＋ vinyl acetate system at 101.3kPa were meas- ured by using double circulating vapor-liquid equilibrium still. The thermodynamic consistency of the VLE data was examined by Herrington method. Experimental data was correlated by non-random two-liquid （NRTL）, Wilson and universal quasichemical （UNIQUAC） parameter models. All the models satisfactorily correlated with the VLE data. The result showed that the NRTL model was the most suitable one to represent experimental data satisfactorily. The system had a minimum temperature azeotrope at 345.71 K and the mole azeotropic composition was 0.0541.