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1.
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. 相似文献
2.
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． 相似文献
3.
Isobaric vapor-liquid equilibrium for methyldichlorosilane-dimethyldichlorosilane-benzene system 总被引：3，自引：0，他引：3
Qiu ZM Xie XL Yu SX Chen WY Xie FX Liu J 《Journal of Zhejiang University. Science. B》2005,6(10):1033-1037
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… 相似文献
4.
Isobaric vapor-liquid equilibrium(VLE) data for three binary systems, chlorobenzene + N,N-dimethylformamide, chlorobenzene + furfural, and chlorobenzene + benzaldehyde, were measured at 50.00 and 101.33 kPa using a modified Rose-Williams still. Gas chromatography was used to analyze the compositions of the samples and no azeotropic behavior was found. All of the measured VLE values were checked by the semi-empirical method proposed by Herington and the point-to-point Van Ness test method modified by Fredenslund. The experimental data were correlated by using the Wilson, the non-random two-liquid and universal quasi-chemical activity coefficient models. The corresponding parameters for the three models were obtained. 相似文献
5.
Succinic acid serves as an important intermediatefor producing a wide variety of industrially importantchemicals such as butanediol, tetrahydrofuran,γ-bu-tyrolactone,n-methyl pyrrolidinone, 2-pyrrolidinine,paints, polymers, plastics, food additives and c… 相似文献
6.
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. 相似文献
7.
Densitiesandviscositiesofliquidmixturesareimportantbothinpracticeandtheory.Inpractice,densitiesarenecessaryinalotofchemicalengineer ingcalculations(i.e.dimensionofstoragedeposits,designofcondensersandboilers,etc.)andalsoin determiningthedynamicviscosity.Thelatterisre quiredintheresolutionofmanyengineeringproblemsinvolvingheattransfer,masstransferandfluidflow.Intheory,density,excessvolumeandviscositycanbeusedtostudytheinteractionspresentinmixtures,suchasdispersionforces,hydrogenbondinginterac t… 相似文献
8.
Vapor-liquid equilibrium data are important forthe design, development, and operation of supercriti-cal fluid separation processes[1].The main method forobtaining phase equilibrium data is experimentation.Most published articles on high-pressure fluid-phaseequilibrium experimental methods focus on supercriti-cal (SC) carbon dioxide because of its low criticaltemperature and pressure, nontoxicity, and lowcost. A feature of SC fluids is that their densities anddensity-dependentproperties are s… 相似文献
9.
在101.325kPa下,用新型泵式沸点仪测定了水-甲醇二元系在不同液相组成时的沸点,并用非分析法由tpx推算了与之平衡的汽相组成y.用最小二乘法分别求出了甲醇-水二元体系的液相活度系数Wilson、NRTL、Margules和Van Laar模型参数,由这些模型参数推算的此二元系的泡点与实验值能很好的吻合.这些模型参数求得的结果,用面积检验法检验得到很好的热力学一致性. 相似文献
10.
《天津大学学报(英文版)》2015,(5)
Liquid-liquid equilibrium data of two ternary systems methyl palmitate+ethanol+glycerol and methyl stearate+ethanol+glycerol at(318.2 and 333.2)K and atmospheric pressure were measured. The values of distribution coefficient and selectivity were calculated, which indicates that glycerol can be separated from fatty acid ester by using ethanol as an extraction solvent. The consistency of the isothermal tie-line data were checked by the Othmer-Tobias equation. The correlation coefficients R2 are higher than 0.993,9 for all the fitted curves. The NRTL activity coefficient model was applied to the correlation of the measured tie-line data. The root mean square deviation(RMSD)values are less than 0.007 for all the systems, which shows a good predictive capability of this model for such systems. 相似文献
11.
Ｎｏｔａｔｉｏｎｓ Ｃｏ—ｉｎｉｔｉａｌｃｏｎｃｅｎｔｒａｔｉｏｎｏｆＭｎＳＯ+4 ,ｍｏｌ/Ｌ Ｃｘ—ｃｏｎｃｅｎｔｒａｔｉｏｎｏｆＰｈＣＨＯａｔｔｉｍｅ ,ｍｏｌ/Ｌ Ｃｔ—ｃｏｎｃｅｎｔｒａｔｉｏｎｏｆＭｎＳＯ+4 ａｔｔｉｍｅ ,ｍｏｌ/Ｌ Ｃｙ—ｃｏｎｃｅｎｔｒａｔｉｏｎｏｆＭｎＯ2 ,ｍｏｌ/Ｌ ｋａ—ｒａｔｅｃｏｎｓｔａｎｔｏｆｏｘｉｄａｔｉｏｎ ,ｍｏｌ/(Ｌ·ｍｉｎ) ｋｂ—ｒａｔｅｃｏｎｓｔａｎｔｏｆｄｉｓｐｒｏｐｏｒｔｉｏｎａｔｉｏｎ ,ｍｏｌ/(Ｌ·ｍｉｎ) ηθ—ｒａｔｉｏｏｆｃｏｎｖｅｒｓｉｏ… 相似文献
12.
This study evaluates latent differential equation models on binary and ordinal data. Binary and ordinal data are widely used in psychology research and many statistical models have been developed, such as the probit model and the logit model. We combine the latent differential equation model with the probit model through a threshold approach, and then compare the threshold model with a naive model, which blindly treats binary and ordinal data as continuous. Simulation results suggest that the naive model leads to bias on binary data and on ordinal data with fewer than 5 levels, whereas the threshold model is unbiased and efficient for binary and ordinal data. Two example analyses on empirical binary data and ordinal data show that the threshold model also has better external validity. The R code for the threshold model is provided. 相似文献
13.
The reaction kinetics of the heterogeneous oxidation oftoluene with Mn^3 was studied by considering the effects of disproportionation of Mn^3 in reaction system,a “parallel”modulus was set up.And then the concentration of Mn^3 in disproportionation and the concentration of benzaldehyde in oxidation were respectively determined in turn.the rate constant,order and pseudo-activation energy of the heterogeneous oxidation were obtained by mathematical deduction and the kinetic equation was concluded.In addition,the reaction mechanism was analyzed.It shows that the results are completely consistent with modulus. 相似文献
14.
The critical curves for binary systems of methane combined with nitrogen, carbon monoxide, carbon dioxide, ethane, propane,
butane and water at temperatures from 125 K to 650 K and pressures from 3.5 MPa to 250 MPa were calculated by using Heilig-Franck
equation of state. This equation of state contains a repulsion term and an attraction term for intermolecular interaction.
With pairwise combination rules for these potentials, three adjustable parameters are needed. The results showed that the
critical curves of the former six binary systems belonged to type I, and CH4+H2O system belonged to type III. The calculated data were compared with the experimental data, which yielded good results for
the pressure-temperature, pressure-composition and temperature-composition behaviors of the seven systems. Moreover, the values
of the adjustable parameters were obtained from the calculation of the critical curves. They can also be used for other relevant
calculation. 相似文献
15.
Jason T. Newsom 《Structural equation modeling》2017,24(4):626-635
The current widespread availability of software packages with estimation features for testing structural equation models with binary indicators makes it possible to investigate many hypotheses about differences in proportions over time that are typically only tested with conventional categorical data analyses for matched pairs or repeated measures, such as McNemar’s chi-square. The connection between these conventional tests and simple longitudinal structural equation models is described. The equivalence of several conventional analyses and structural equation models reveals some foundational concepts underlying common longitudinal modeling strategies and brings to light a number of possible modeling extensions that will allow investigators to pursue more complex research questions involving multiple repeated proportion contrasts, mixed between-subjects × within-subjects interactions, and comparisons of estimated membership proportions using latent class factors with multiple indicators. Several models are illustrated, and the implications for using structural equation models for comparing binary repeated measures or matched pairs are discussed. 相似文献
16.
The phase equilibrium data of CO_2 –hydrocarbon binary mixtures are important for the design and operation of CO_2 flooding, coal liquefaction, and supercritical extraction processes. Numerous pieces of binary phase equilibrium data have been obtained. Thus, models for the accurate calculation of binary and multicomponent mixtures must be developed on the basis of existing data. In this work, 3578 vapor–liquid phase equilibrium data points for 10 CO_2 –hydrocarbon binary mixtures, including CO_2 –butane, CO_2 –pentane, CO_2 –isopentane, CO_2 –hexane, CO_2 –benzene, CO_2 –heptane, CO_2 –octane, CO_2 –nonane, CO_2 –decane, and CO_2 –undecane, were collected. The PR and PR-BM equations of state(EOS) in combination with relevant mixing rules were used to calculate the phase equilibrium data of the CO_2 –hydrocarbon binary mixtures. The binary interaction parameter k ij in the PR EOS was temperature independent, whereas parameters in the PR-BM EOS were functions of temperature. Thus, the phase equilibrium data and other thermodynamic properties of the binary and multicomponent mixtures at different temperatures and pressures can be calculated by using the parameters obtained in this work. The PR-BM EOS performed better than the PR EOS, and the average absolute deviations over the temperature range of 255.98–408.15 K calculated by the PR EOS and PR-BM EOS were less than 5.74% and 3.36%, respectively. The results calculated by the two EOS were compared with those calculated by other models, such as PPR78, PR + LCVM + UNIFAC, KIE + PR EOS + HV, and PSRK. The phase equilibrium data of CO_2 –butane–decane, CO_2 –hexane–decane, and CO_2 –octane–decane ternary mixtures were calculated by the two EOS. The average overall deviations for the CO_2 mole fractions calculated by the two EOS were less than 7.66%. 相似文献
17.
利用定态流法对超临界CO2流体萃取咖啡因水溶液进行研究,测定咖啡因水溶液在CO2中的溶解度数据,并采用P-R状态方程对文献中SVE体系咖啡因的溶解度数据和实验测定的溶解度数据进行关联,得到相应的二元相互作用参数．计算值和实验值比较结果表明：P—R状态方程模型计算值和实验数据吻合较好． 相似文献
18.
This research on the solvent effects of 2-methyl-4,5-dimethoxy-3-oxo-2H-pyridizine (MDOP) in binary solvent systems on the
infrared spectra for MDOP in n-hexane/CHCl3 mixture solvents showed that there were three forms of carbonyl stretching vibration band [ν(C=O)] of MPOP as the mole fraction
of CHCl3 in the binary solvents changes. In pure n-hexane solvent, the ν(C=O) of MDOP appeared at a relatively high wavenumber. With
CHCl3 added, the ν(C=O) shifted to lower wavenumbers. Two new bands were observed over a certain range of mixture solvent compositions.
The origin of the bands was discussed in the terms of two kinds of hydrogen bond together with their individual dependence
on mixture composition. Comparisons were drawn for the solvent sensitivities of ν(C=O) for propanone.
Project supported by the Analysis and Measurement Foundation of Zhejiang Province, China. 相似文献
19.
The iron-loaded organic phase of naphthenic acid-isooctyl alcohol-kerosene was prepared, and the process kinetics of hydrothermal stripping of iron from the phase was studied. Several factors affecting hydrothermal stripping, such as the polymer of naphthenic acid, initial concentrations of iron and naphthenic acid, temperature and agitation time, were investigated, and based on experimental results and theoretical analysis, two kinetic models were established.The stripping rate equation suggests that the hydrothermal stripping process activation energy is 96.4 kJ·mol-1 and the stripping is controlled by hydrolysis of naphthenic complex of iron. The values calculated by the stripping fraction equation comparatively accord with the experimental data. 相似文献
20.
马知伊 《韩山师范学院学报》2013,(3):50-54,59
用水蒸气蒸馏法、溶剂萃取法从新鲜肾茶叶中提取挥发油,用气相色谱-质谱联用技术对挥发油的化学成分进行了分析,用气相色谱面积归一化法测定了各个成分的相对百分含量.共分离出82个峰,鉴定出82个化学成分.其中主要成分柏木醇(53.64%)、斯巴醇(4.13%)、1-辛烯-3-醇(3.92%)、α-柏木烯(3.47%)、蓝桉醇(3.24%)和β-柏木烯(2.51%). 相似文献