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1.
采用沸点仪测定了顺丁烯二酸酐和邻苯二甲酸二甲酯二元体系在4.00, 8.00和12.00 kPa下的等压气液平衡数据以及纯DMP组分饱和蒸气压数据, 将实验数据回归得到了纯DMP在417~525 K范围内的Antoine方程. 根据实验平衡温度、 压力和组成数据进一步回归得到NRTL方程参数, 推算出平衡气液相组成, 并利用UNIFAC方程对实验数据进行了预测, 其结果与沸点仪测定结果及NRTL拟合的结果基本相符.  相似文献   

2.
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   

3.
本文报导了醋酸-水、醋酸-醋酸乙烯酯、水-醋酸乙烯酯等三对二元系以及醋酸-水-醋酸乙烯酯三元系在液相完全互溶区的气液平衡实验数据。文中还计算了经校正了醋酸气相缔合后的活度系数,作了热力学一致性校验,并尝试用NRTL式进行关联。当使用三对二元系的NRTL特征参数,对三元系液相完全互溶区的气液平衡进行了预测,与实验结果基本相符。三元系液相部分互溶区的实验数据与热力学关联的结果,将于第Ⅱ报中报导。  相似文献   

4.
测定了在20℃下甲基叔丁基醚-甲醇-水及甲基叔丁基醚-叔丁醇-水两组三元体系的液液平衡数据和在常压下各三元体系中二元配偶物系的汽液平衡数据。并将所测定的两组三元液液平衡数据与二元系数据用NRTL 及UNIQUAC 方程所得的参数推算的结果进行了比较,获得较满意的结果。  相似文献   

5.
采用小沸点仪测定了马来酸酐和1,2-环己烷二羧酸二异丁酯二元系统在不同配料组成条件下的温度与压力数据,并通过内插法得到不同压力下的温度与配料组成的数据.进一步采用单纯形法优化NRTL方程参数,推算了平衡气液相组成,发现该二元系统具有最高压力恒沸点,且该恒沸点随压力的变化显著.当压力降低至20 kPa时, 由温度随气相组成的变化趋势知该恒沸点将趋于消失.  相似文献   

6.
采用平衡法测定了丙烯腈+水、己二腈+水、丙腈+水三个二元体系在不同温度(303.15、313.15、323.15、333.15K)下的液-液相平衡数据;并采用NRTL(α=0.2,α=0.3)模型和UNIQUAC模型对液-液平衡数据进行了关联.结果显示,NRTL和UNIQUAC模型对三个二元体系在不同温度下的互溶度关联的目标函数值均小于1×10-17,实验值与计算值吻合较好,绝对偏差小于0.009,关联精度较高.该研究结果可为丙烯腈、丙腈和水三元平衡溶解度数据的模拟和预测提供可靠的基础数据,并对电解二聚法生产己二腈中电解液的分离提纯工艺具有一定的指导意义.  相似文献   

7.
本文用流动汽液平衡釜测定了戊酮-3-正丙醇丁酮-戊醇-1-两个体系三个温度下的等温液平衡数据,三个温度下的数据均通过热力学一致性检验,并用Wilson方程和UNI-QUAC方程对数据进行了关联,平均汽相偏差小于0.01,精度令人满意。  相似文献   

8.
H测定过MgSO_4-C_2H_5OH-H_2三元系在25℃、50℃、75℃的液固平衡和部分不饱和溶液汽液平衡的总压和分压。本文补充了30℃、0℃和-5℃时的溶解度数据,得到分层温度和浓度范围,绘出了溶解度图。测定了25℃和30℃饱和溶液的密度,粘度和平衡总压力。根据Jaques“假二元系”理论用Wilson、Uniquac和NRTL活度方程计算了溶  相似文献   

9.
若干酮-醇体系的汽液平衡   总被引:1,自引:0,他引:1  
本文用流动汽液平衡釜测定了①戊酮-3-正丙醇③丁酮-戊醇-1两个体系三个温度下的等温汽液平衡数据,三个温度下的数据均通过热力学一致性检验,并用Wilson方程和UNI-QUAC方程对数据进行了关联,平均汽相偏差小于0.01,精度令人满意。  相似文献   

10.
研究Li_2SO_4-EtOH-H_2O体系25℃气液平衡及液相的粘度和密度。湿渣法确定平衡固相在整个浓度范围内均为Li_2SO_4·H_2O。用经验公式ln(y/y_0)=K_1x K_2x~2 K_2x~3对体系的溶解度和密度数据进行关联。硫酸锂加入到液相后由于盐离子静电作用对乙醇-水体系粘度的影响。按Jaques的假二元体系模型,用WILSON,NRTL方程关联气液平衡数据。  相似文献   

11.
Anderegg G  Kholeif S 《Talanta》1994,41(9):1507-1522
Different Debye-Hückel expressions for the activity coefficients of species in aqueous solution in the ionic strength range I = 0-3.5m (3M) are used for the extrapolation of equilibrium constants data to I = 0 and the interpolation to unknown I values. This may be accomplished using four or more values of the equilibrium constants that are equally well distributed on the I scale. The interpolated and extrapolated equilibrium constant values obtained are quite satisfactory and within the experimental error of the corresponding equilibrium constants. The values at I 0.1 are very important as they can particularly influence the equilibrium constant value calculated at I = 0 and for which the error can reach 0.1 log unit or more. The values at I 1.5 can also influence the extrapolated value at I = 0 and the interpolated value at a given I when an inadequate extrapolation model is selected. Among the expressions used, only those with two or more unknown parameters are suitable for such calculations.  相似文献   

12.
Techniques of data reduction and methods of calculation have been given for the determination of equilibrium constants by titration calorimetry. It has been shown how, starting with typical titration calorimetry data, the apparent heat liberated in the reaction vessel can be calculated, corrected for extraneous heat effects, and used to solve for the equilibrium constant and enthalpy change value(s) for the reaction(s) under investigation. Equations are given for calculating the energy contributed to the overall heat effects measured in the reaction vessel by processes other than chemical reactions such as heat of stirring, heat losses, heat of dilution, etc., and by chemical reactions other than the one(s) for which equilibrium constant(s) are sought. Mathematical techniques and equations are presented for calculating equilibrium constants and enthalpy change values from titration data by least squares analysis.  相似文献   

13.
《Fluid Phase Equilibria》1987,32(2):151-162
This article reports the solubilities and equilibrium data of the ternary mixture water + acetic acid + methyl ethyl ketone at 25, 35 and 45°C, and the equilibrium data of the binary system water + methyl ethyl ketone over the range 20–55°C. NRTL and UNIQUAC equations have been fitted to the experimental data for the ternary system, which are also compared with the values predicted by the UNIFAC method.  相似文献   

14.
A set of P vs. x data for vapor-liquid equilibrium properly contains the pure-component vapor pressures. These values are as uncertain as the values for other measured pressures, and data reduction should yield smoothed values for these as well as for the other pressures. However, the vapor pressures also appear as constants in the reducing equation; here they must have assigned values. This paper shows how the results of data reduction are influenced by different treatments of the vapor pressure.  相似文献   

15.
The knowledge of sorption processes of nonelectrolytes in solution by solid adsorbents implies the study of kinetics, equilibrium, and thermodynamic functions. However, quite frequently the equilibrium isotherms are studied by comparing them with those corresponding to the Giles et al. classification (1); these isotherms are also analyzed by fitting them to equations based on thermodynamic or kinetic criteria, and even to empirical equations. Nevertheless, information obtained is more coherent and satisfactory if the adsorption isotherms are fitted by using an equation describing the equilibrium isotherms according to the kinetic laws. These mentioned laws would determine each one of the unitary processes (one or more) which condition the global process. In this paper, an adsorption process of prednisolone in solution by six carbonaceous materials is explained according to a previously proposed single model, which allows to establish a kinetic law which fits satisfactorily most of C vs t isotherms (2). According to the above-mentioned kinetic law, equations describing sorption equilibrium processes have been deducted, and experimental data points have been fitted to these equations; such a fitting yields to different values of adsorption capacity and kinetic equilibrium constants for the different processes at several temperatures. However, in spite of their practical interest, these constants have no thermodynamic signification. Thus, the thermodynamic equilibrium constant (K) has been calculated by using a modified expression of the Gaines et al. equation (3). Global average values of the thermodynamic functions have also been calculated from the K values. Information related to variations of DeltaH and DeltaS with the surface coverage fraction was obtained by using the corresponding Clausius-Clapeyron equations.  相似文献   

16.
本文提出了具有相同电荷的同号离子间作用力相等的假定, 简化了Pitzer的电解质溶液活度系数计算公式, 用此公式, 计算了H_2SO_4-CoSO_4-CuSO_4水相体系各单个离子活度系数以及水的渗透系数。本文还应用由作者提出的工作参考态法, 应用改进的Scatchard-Hildebrand模型计算了EHEHPA-CoSO_4-CuSO_4萃取体系中有机相各组分的活度系数以及萃取反应热力学平衡常数.  相似文献   

17.
CO2 and N(2) adsorption kinetics and equilibrium behaviours have been studied with silicalite, NaY and 13X by using concentration pulse chromatography for the separation of these gases in the present study. Adsorption Henry's Law constants, the heat of adsorption values, micropore diffusion coefficients and corresponding activation energies are determined experimentally and the three different mass transfer mechanisms are discussed. From the equilibrium data, the corresponding separation factors are obtained for the adsorption separation processes. The heat of adsorption values as well as the Henry's Law adsorption equilibrium constants of CO(2) are much higher than those of N(2) for all the adsorbents studied. 13X, NaY and silicalite all have good separation factors for CO(2)/N(2) system based on equilibrium processes. The order of the equilibrium separation factors is 13X (Ceca)>13X (Zeochem)>NaY (UOP)>silicalite (UOP). Equilibrium selectivity favours CO(2) over N(2). Micropore diffusion resistance is the definite dominant mass transfer mechanism for CO(2) with silicalite and NaY.  相似文献   

18.
13 C NMR chemical shifts of sixteen organic bases, hydrogen-bonded with trifluoroacetic acid in deuteriochloroform, are used to calculate equilibrium constants for self-association of acid and for hydrogen bonding of base with various acid n-mers. In this treatment each hydrogen bond of the species in equilibrium is assigned a free energy. The equilibrium constants then correspond to changes in these energies. Thermodynamic models are proposed which differ in the extent to which a given hydrogen bond perturbs the free energies of neighboring bonds in the molecular aggregates. Each furnishes a minimum set of independent, freely variable equilibrium constants, the values of which are then determined through a least squares fitting of the experimental data by an iterative procedure.  相似文献   

19.
The method of Hanks et al. was used with the heat of mixing data of McFall et al. for 1,3-butadiene + propylene, 1-butene + methyl tert.-butyl ether, and carbon disulfide + methanol to predict the vapor-liquid equilibrium behavior for these systems. The method involves curve-fitting an excess enthalpy model derived from an excess Gibbs energy model by means of the Gibbs-Helmholtz equation to the heat of mixing data, determining the adjustable parameters from this fit, and using the original excess Gibbs function equation to predict the vapor-liquid equilibrium behavior. The predicted vapor-liquid equilibrium values were compared with experimental values and good agreement was found.  相似文献   

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