Isobaric vapor-liquid equilibrium for methyldichlorosilane-methyltrichlorosilane-dimethyldichlorosilane system

This paper describes measurement of vapor-liquid equilibrium (VLE) data of methyldichlorosilane-methyltrichlorosilane-dimethyldichlorosilane system and that of the three binary systems at 101.325 kPa with a new pump-ebulliometer. The equilibrium composition of the vapor phase was calculated from pTx by indirect method. The model parameters of the liquid activity coefficient of the Wilson, NRTL, Margules and van Laar equations was corrected by the least square method. The ternary system VLE data were predicted by the Wilson equation, with the calculated boiling points showing good agreement with the experimental data.     

Isobaric vapor-liquid equilibrium for methyldichlorosilane-dimethyldichlorosilane-benzene system

INTRODUCTION Vapor-liquid equilibrium (VLE) data are veryimportant in the design and operation of separationprocesses in the chemical industry. Such informationcan be obtained experimentally or estimated by usinggeneralized methods for calculation of the propertiesof mixtures. For ideal system, it is relatively easy toestimate vapor-liquid equilibrium. However, mostsystems of industrial interest show deviations fromthe ideal behavior.The methyldichlorosilane-dimethyldichlorosi- lane-ben…     

减压下N，N-二甲基乙酰胺-水二元汽液平衡数据的测定与关联

采用改进的Ellis汽液平衡釜,在35kPa压力下,测定了N,N-二甲基乙酰胺一水二组分物系的汽液平衡数据．利用Herington面积检验法对实验数据进行了热力学一致性检验,结果表明,所测定的汽液平衡数据满足热力学一致性．分别用VanLaar和Wilson活度系数方程关联了实验数据,两者结果较接近．汽相组成和泡点温度的平均绝对误差分别为0．0041,1．622l℃（VanLaar）和0．0076,1．6057℃（wilson）．实验数据和关联结果为减压精馏分离N,N-二甲基乙酰胺和水的过程开发提供了基础数据．     

Vapor-liquid equilibrium simulation of binary and ternary mixtures of CH4, C2H4 and iso-C4H10

The vapor-liquid equilibrium（VLE） properties for the binary and ternary mixtures of CH4,C2H4 and isoC4H10 are of great importance in the recovery of ethylene from mixture containing CH4 and C2H4 with iso-C4H10 as solvent.Hence,Gibbs ensemble Monte Carlo（GEMC） simulations were used to estimate vapor-liquid equilibrium for the binary and ternary mixtures of CH4,C2H4 and iso-C4H10 with the united atom potential NERD model.The selected simulation conditions are based on the experiment in the literature.The results of this work were shown to be in satisfactory agreement with available experimental data and predictions of Peng-Robinson equation of state.The structure of simulated liquid phase is also characterized by radial distribution function（RDF）,which contributes to further understanding of the VLE curve of these systems.RDF is not sensitive to the pressure and temperature range.With the increase of pressure or the decrease of temperature,the molecules tend to gather together.     

甲醇-水、水-丙酸和甲醇-丙酸体系汽液平衡的热力学性质

用新型泵式沸点仪测定了在101．325kPa下甲醇-水、水-丙酸、甲醇-丙酸3个二元系在不同液相组成时的沸点，并用间接法Tpx推算了甲醇-水、水-丙酸、甲醇-丙酸3个二元系的汽相平衡组成y.3个二元体系活度系数的关联分别用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．同时，用这些模型参数来计算它们的汽相组成y．所得的液相活度系数来计算3个二元体系的过量吉布斯自由焓函数G^E／RT，并且研究的所有体系之间不存在共沸点．计算的沸点温度与实验的所测得的沸点温度吻合良好，由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得到很好的热力学一致性．     

DMF-CHCl_3体系汽液相平衡数据的测定与关联

为获得二甲基甲酰胺(DMF)与氯仿(CHCl3)精馏分离的基础热力学数据,实验采用改进型的Rose平衡釜测定了DMF-CHCl3体系在760mmHg下的汽液相平衡数据,并分别用NRTL和Margules模型对实验数据进行关联。结果表明:实验数据满足热力学一致性的检验,且NRTL和Margules模型的计算结果与实测结果偏差小,平均绝对误差分别为0.0026和0.0010,平均相对误差分别为1.81%和1.23%,可满足工业精馏工艺过程设计的需要。     

电导法测定298K时NdCl3在DMF和H2O中的活度系数

应用电导法在298K时测定了稀土氯化盐NdCl3在混合溶剂(DMF-H2O)中的电导率;利用公式计算了NdCl3的摩尔电导率;应用Kohlraush经验规则,使用Origin软件进行线性拟合,外推得到298K时NdCl3在混合溶剂(DMF-H2O)中的无限稀释摩尔电导率λ0 =300.01 (S*cm2 *mol-1);应用Debye-Hücker 和Osager-Falkenhangen公式计算了NdCl3在混合溶剂(DMF-H2O)中的活度系数,并讨论了在298K时浓度对稀土盐NdCl3溶液活度系数的影响,随稀土氯化盐溶液浓度的增加,稀土盐溶液的活度系数降低.