环己烷、正丁醇、甲苯有关二元体系加压相平衡

以环已烷、正丁醇、甲苯为代表,进一步研究了烷烃、芳烃和低级醇在加压下的相平衡规律。测定了有关3个二元体系在101.3、304.0、506.6、709.3、911.9kPa下汽液平衡数据,对实测数据进行了统一关联,计算结果与实测值符合良好。环己烷-正丁醇、正丁醇-甲苯体系在所测压力下均形成最低共沸点。     

甲基二氯硅烷-甲基三氯硅烷-甲苯三元体系等压汽液平衡

In this paper, the boiling points of methyldichlorosilane-methyltrichlorosilane-toluene system and of the three binary systems are determined at 101.3 kPa with a new type of magnetic pump-ebulliometer.The VLE data of the three binary systems, respectively,are correlated with the Margules, van Laar, Wilson, and NRTL equations. The equilibrium composition of the vapor phase of three binary systems are calculated from TPX by indirect method. Activity coefficients are calculated after accounting for the nonideality of the vapor phase. The model parameters of liquid activity coefficient are correlated by the least square method. The vapor pressure of the pure components are obtained by using Antoine constants from the literature. The VLE data of ternary system are predicted by the Wilson equation. The calculated boiling points show good agreement with the experimental data.     

甲基三氯硅烷、甲基乙烯基二氯硅烷、甲苯的二元及三元体系等压汽液平衡

引　言甲基乙烯基二氯硅烷是重要的有机硅单体和硅烷偶联剂 ,在硅橡胶、涂料、印染、化妆品等领域有着广泛的应用 .在合成甲基乙烯基二氯硅烷的过程中 ,甲苯作为均相催化剂的载体以及反应的媒介体循环使用 ,甲基三氯硅烷是副产物 ,在分离过程的设计中需要有关甲基三氯硅烷、甲基乙烯基二氯硅烷、甲苯体系的汽液平衡数据 ,此前文献尚未见报道 .为了满足过程开发与工程设计的需要 ,本研究测定了甲基三氯硅烷、甲基乙烯基二氯硅烷和甲苯三元体系及其 3个二元体系的相平衡数据 ,并进行了热力学关联 .1　实验部分1 1　试　剂甲基三氯硅烷 :江西蓝…     

甲醇－水、甲缩醛－甲醇和甲缩醛－水系统的汽液平衡

用泵式沸点仪测定了常压下甲醇－水、甲缩醛－甲醇、甲缩醛－水三个二元系在不同液相组成时的沸点，并用间接法由ＴＰｘ推算了与之平衡的汽相组成。用最小二乘法求出了三个二元系的液相活度系数模型参数，由模型参数推算的三个二元系的泡点与实验值能很好的吻合。     

丙烯腈-乙腈-水三元体系汽液平衡的研究

在大量实验数据的基础上,对丙烯腈-乙腈-水三元体系汽液平衡组成之间的规律性进行了研究。采用多参数Wilson方程进行关联,对该非理想性很大而且液相分层的三元体系能获得极为满意的结果。该式所采用的参数都由相应的二元体系的参数提供。对99组汽液平衡的实验数据进行计算,汽相组成（分子分数）的平均绝对误差为0.0098。用同一关联式对此三元体系的液液平衡曲线的结点进行关联,亦获得了满意的结果。本文在关联式的基础上还作出了汽液平衡组成、沸点组成、不同含水量下相对挥发度等曲线图,可方便地用于设计计算中。     

甲基二氯硅烷-甲基三氯硅烷-苯三元体系等压汽液平衡

利用新型泵式沸点仪,在101.3 kPa下测定了甲基二氯硅烷-甲基三氯硅烷-苯体系以及3个二元体系在不同液相组成时的沸点;对所测的二元系数据,采用间接法由TPx推算了与之平衡的汽相组成,再用最小二乘法分别求出了二元体系的Wilson、NRTL、Margules和van Laar 4种模型的最佳配偶液相活度系数模型参数,并由二元最佳配偶参数推算了甲基二氯硅烷-甲基三氯硅烷-苯三元体系的气相组成和泡点温度,与实验测得的温度值进行了比较,其拟合精度良好,关联结果令人满意.     

甲缩醛—甲醇—水三元系的汽液平衡

甲缩醛－甲醇－水三元系的汽液平衡邱祖民骆赞椿胡英（南昌大学化工系，南昌３２００２９）（华东理工大学化工系，上海２００２３７）关键词沸点仪汽液平衡甲缩醛甲醇１前言在浓醛生产中需要甲缩醛－甲醇－水三元系的汽液平衡数据，此前尚未见过报导。本文试图以文献［１...     

Vapor pressure and normal boiling point predictions for pure methyl esters and biodiesel fuels

Temperature dependent vapor pressures of the methyl esters of fourteen fatty acids that are commonly present in biodiesel fuels were predicted by the Antoine equation and a group contribution method. The predicted boiling points of these esters up to a pressure of 100 mmHg were within ±1.0% of reported data for these two methods. Normal boiling points were determined from both the predicted vapor pressure and a correlation equation and the prediction errors were less than 5 K comparing to available published data. The vapor pressure and normal boiling points of 19 real-world biodiesel fuels were predicted and compared with reported data where available. The prediction errors of normal boiling points were less than 1.0%, and the predicted vapor pressures were also observed to closely match the reported data among the methyl esters of soybean oil, rapeseed oil and tallow. The predicted results showed that, except for coconut and butterfat, most of the methyl esters of the vegetable oils and animal fats had a normal boiling point in the range of 620–630 K. A sensitivity analysis indicated that the variation of fatty acid composition and the uncertainty of the normal boiling point of C18:2 were the main factors that affected the predicted normal boiling points of the biodiesel fuels.     

甲醇-乙酸、甲醇-丙酸和乙酸-丙酸二元体系汽液平衡

用新型泵式沸点仪测定了101.325 kPa下甲醇-乙酸、甲醇-丙酸和乙酸-丙酸3个二元系在不同液相组成时的沸点,用过量自由能函数Q,采用间接法由Tpx推算了3个二元体系的汽相平衡组成y。3个二元体系活度系数分别用Wilson模型、NRTL模型、Margules模型和Van Laar模型进行关联,用最小二乘法求出了它们的液相活度系数模型参数。用所得的液相活度系数来计算此二元体系的过量吉布斯自由能函数GE/(RT)。用3个二元系模型参数对所测的数据进行关联,建立该系统汽液平衡的热力学模型并计算平衡时的泡点温度。计算的泡点与实验的沸点吻合良好,经面积积分法检验,这些模型参数计算的3个二元体系相平衡数据具有很好的热力学一致性。     

3-羟基丁酸乙酯-巴豆酸乙酯-乙醇三元体系等压汽液平衡

在汽液双循环玻璃平衡釜中测定3-羟基丁酸乙酯、巴豆酸乙酯、乙醇的二元及三元体系的等压汽液平衡数据,用积分法对其进行了热力学一致性检验.回归实验数据得到3-羟基丁酸乙酯和巴豆酸乙酯的Antoine方程参数.用Wilson活度系数方程对实验数据进行了关联,取得了较好的结果.     

The vapour-liquid equilibrium of ternary systems with limited miscibility at atmospheric pressure

The complete study of the vapour-liquid equilibrium of ternary systems with limited miscibility requires vapour-liquid equilibrium determinations and liquid-liquid equilibrium determinations at boiling point. The vapour-liquid equilibrium was determined by means of an equilibrium still based on the principle of Giilespie but modified in such a way that an accurate boiling point measurement, even for systems with heterogeneous liquid was possible and that the vapour phase was analysed without previous condensation. Two ternary systems have been studied: the system methanol-ethylacetate-water and the system ethanol-ethylacetate-water. The ternary data have been predicted by means of the equation of Renon and Prausnitz. The parameters are determined by correlating the binary data. The ternary vapour-liquid equilibrium are predicted within 1-2. 10 ^?2 mol fraction for the vapour composition and 1°C for the boiling point. The position of the predicted tielines of the liquid-liquid equilibrium at boiling point was almost coinciding with the position of the experimental tielines. There was a slight deviation of the predicted and experimental binodal.     

测纯物质常沸点汽化热的一种改进方法

应用八十年代提出的新R-K状态方程式,改进纯物质常沸点汽化热的剩余函数预测法,推导出纯物质常沸点汽化热的新计算方程式。并应用该方程式,由最基本的物性数据T_b,T_c和P_c,预测了400种各类物质的常沸点汽化热,与实验值比较,预测准确度优于其它方程。     

Predicting thermal conductivity of binary liquid mixtures on basis of coordination number

By applying a model of a randomly mixed packing of spheres of two sizes to binary liquid mixtures, the thermal conductivity of the mixture is related to the physical properties of each component through the number of contact points. Further, two parameters are introduced to account for the effect of the hydrogen bond and are correlated with the Lennard-Jones (6-12) parameters σ and ?, or the boiling temperature. In comparing the calculated values with the experimental data for 13 aqueous liquids and 21 non-aqueous liquid systems, the present equation turns out to be more accurate than previous ones.     

由溶液蒸汽压或沸点确定平衡气相组成的直接法

本文提出一种由溶液的蒸汽压或沸点确定平衡气相组成的直接法。基本微分方程由Gibbs- Duhem式导得,能方便地利用迭代法求解。本方法可以顺利地应用于二元系,原则上亦可应用于多元系。提供的若干二元系与三元系实例表明,计算结果与实验值良好一致。     

混合制冷工质核态沸腾的传热研究

Heat transfer coefficients in nucleate pool boiling were measured on a horizontal copper surface for refrigerants, HFC-134a, HFC-32, and HFC-125, their binary and ternary mixtures under saturated conditions at 0.9MPa. Compared to pure components, both binary and ternary mixtures showed lower heat transfer coefficients.This deterioration was more pronounced as heat flux was increased. Experimental data were compared with some empirical and semi-empirical correlations available in literature. For binary mixture, the accuracy of the correlations varied considerably with mixtures and the heat flux. Experimental data for HFC-32/134a/125 were also compared with available correlated equation obtained by Thome. For ternary mixture, the boiling range of binary mixture composed by the pure fluids with the lowest and the medium boiling points, and their concentration difference had important effects on boiling heat transfer coefficients.     

Correlations for prediction of diffusion in liquids

Based on an extensive experimental data collection (about 1925 points), empirical correlations for the estimation of binary liquid diffusion coefficients have been developed. The new correlations for organic mixtures and for aqueous solutions (including dissolved gases) require only well known and simple parameters like the viscosity of the solvent and the molar volumes of solute and solvent at the normal boiling point. They are shown to predict the limiting diffusion coefficients with the same or sometimes better accuracy than established correlations which make use of additional parameters. The concentration dependence of the mutual diffusion coefficients can be estimated from the knowledge of the two limiting diffusion coefficients and thermodynamic data. Established equations are investigated and classified for different groups of systems e.g. nonpolar + nonpolar, nonpolar + polar and polar + polar liquid mixtures.     

Vapor-liquid equilibria for 1,1,1-trifluoro-2-(2,2,2-trifluoroethoxy)ethane +2-methyl-2-propanol and pentane+1,1,2,2-tetrafluoro-1-(2,2,2-trifluoroethoxy)ethane system

Isobaric vapor-liquid equilibrium (VLE) for two binary systems of 1,1,1-Trifluoro-2-(2,2,2-trifluoroethoxy) ethane+2-methyl-2-propanol and pentane+1,1,2,2-tetrafluoro-1-(2,2,2-trifluoroethoxy)ethane system have been measured at 101.3 kPa. The measurements were made in an equilibrium still, developed in a previous study, with circulation of both the vapor and liquid phases. The binary isobaric systems exhibit minimum boiling azeotropes. The thermodynamic consistencies of the experimental data were good by the Van Ness et al. and Herington methods. The experimental data for the binary systems investigated were correlated with activity coefficient equations. The nonrandom two-liquid (NRTL) equation yielded a good correlation of activity coefficients.     

Crisis during the boiling of binary mixtures of liquids

The existing notions on the crisis of the boiling of binary mixtures are analyzed. It is shown that the maximal values of the critical thermal load coincide with the so-called singular points corresponding to defined compounds. The search for new binary systems with similar properties can be based on the investigation, first of all, of these binary points.     

Phase behaviour prediction in supercritical systems using generalized solute critical properties

Trebble and Sigmund (1990) have recently published a generalized form of the Peng-Robinson (1976) equation of state in which binary interaction parameters are predicted as a function of the species critical volumes, dipole moments, and quadrupole moments. In this study, the critical properties of solutes heavier than normal hexane are correlated against molar mass, normal boiling temperature, and group type (i.e. paraffinic, olefinic, naphthenic or aromatic). This extension further facilitates the use of the generalized Peng-Robinson equation in calculating phase behaviour of supercritical systems in which solute critical properties are unknown or uncertain. Calculation of phase behaviour using the extended correlation is shown to be of the same quality as the previous generalization (which required solute critical constants) for 38 binary systems covering broad temperature and pressure ranges.     

非电解质水溶液黏度的关联

许多化工过程的设计需要估算含水体系的黏度,但目前的黏度关联方法用于含水体系时误差较大.今以作者所在课题组近期提出的非水液体混合物黏度关联方程为基础,通过引入形状因子,得出了一个非电解质水溶液的黏度方程.该方程可用于二元非电解质水溶液黏度的关联,且能利用二元黏度得到的关联参数推算三元非电解质水溶液的黏度.该方程对54个二元非电解质水溶液体系黏度(总计2876个黏度数据点)关联的总平均相对偏差为4.60%;对7个三元非电解质水溶液体系黏度(总计352个黏度数据点)推算的总平均相对偏差为3.75%.结果表明,该方程具有较高的关联精度和推算精度.