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1.
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   

2.
基于EHS(Environment-Health-Safety)理念的考虑,对双液系气液平衡相图实验沸点仪作了相应改进。改进后的实验装置在保持原有装置操作方便、测量准确的基础上,能够更好地满足在化学实验教学中贯彻EHS理念的要求。  相似文献   

3.
The origins of middle surfactant phases (D and Dp′) were investigated in the composition-temperature (49–73 °C) space of a water/hexaethyleneglycol dodecyl ether (C12EO6)/propanol/heptane system at atmospheric pressure. Two types of three-phase bodies exist in the dilute C12EO6 region of the four-component composition tetrahedron at 49.0 °C. A cone-like three-phase body consisting of aqueous (W), Dp′, and oil (O) phases becomes thinner with increasing temperature, and collapses into the superimposed critical tie lines (CTL) at 51.7 °C. One end of the superimposed CTL is a critical double end point where the closed-loop coexistence curve of the Dp′ and O phases disappears. The chiral three-phase body consisting of W, D, and O phases shrinks with increasing temperature, and finally vanishes at the tricritical point near 72.5 °C. The roles of C12EO6 and propanol are discussed and the conditions for the middle surfactant phases are discussed on the basis of the whole series of three-phase behavior. Received: 9 July 1998 Accepted in revised form: 25 August 1998  相似文献   

4.
Adsorption data of nitrogen and methane on micro-porous activated carbon and on meso-porous silica gel were measured near the critical temperature. It was found that the values of the compressibility factor (z) exerted a significant effect on the behavior of isotherms. Selection of reliable z-values is very important for the analysis of experimental results obtained near the critical temperature. The isotherms on activated carbon always show type-I features at sub- and supercritical temperatures, but those on silica gel remarkably show a change from type-II at sub-critical temperatures to type-I at supercritical temperatures. The critical temperature appears to be shifted up in some case.  相似文献   

5.
Supercritical carbon dioxide(SC-CO2 ) is considered in green chemistry as a substitute for conventional solvents in chemical reactions due to its environmentally benign character. Recently we have reported the homogeneous hydroformylation of propylene in supercritical carbon dioxide( SC-CO2 ) , which is an example of this kind of application of carbon dioxide. The determination for the critical parameters of carbon dioxide + butyraldehyde mixtures is necessary for this reaction design which is the focus of the present paper. The critical parameters of the binary systems were determined via the static visual method at a constant volume with the molar fraction of butyraldehyde ranging from 1.0% to 2. 2% and the pressure ranging from 5 to 10 MPa. The experimental results show that the critical pressure and temperature increased with increasing the molar fraction of butyraldehyde. The bubble(dew) temperatures and the bubble (dew) pressures for the binary systems were also determined experimentally. The p-T Figures at different compositions of the binary systems were described. In addition, the critical compressibility factors Zc of the binary systems at different concentrations of n-butyraldehyde were calculated. It was found that the critical compressibility factor values of the binary systems decreased with increasing the molar fraction of n-butyraldehyde in the experimental range.  相似文献   

6.
High‐pressure vapor‐liquid phase equilibrium data for carbon dioxide+isopentanol were measured at temperatures of 313.2, 323.1, 333.5 and 343.4 K in the pressure range of 4.64 to 12.71 MPa in a variable‐volume high‐pressure visual cell. The experimental data were well correlated with Peng‐Robinson equation of state (PR‐EOS) together with van der Waals‐2 two‐parameter mixing rule, and the binary interaction parameters were obtained. Henry coefficients and partial molar volumes of CO2 at infinite dilution were estimated based on Krichevsky‐Kasarnovsky equation, and Henry coefficients increase with increasing temperature, however, partial molar volumes of CO2 at infinite dilution are negative and the magnitudes decrease with temperature.  相似文献   

7.
8.
超临界二氧化碳二元体系相平衡性质的研究   总被引:9,自引:1,他引:9  
采用固定体积可视观察法测定了CO2+甲苯、CO2+环己烷、CO2+正丁醛、CO2+异丁醛、CO2+甲醇及CO2+乙醇二元体系的临界点性质,为超临界萃取和化学反应提供基础数据.在对二元体系相行为与单组分超临界相行为进行比较的基础上,对不同化学物质及不同配比的二元体系临界点与二氧化碳临界点之间的关系进行了讨论.  相似文献   

9.
在带有石英视窗的可变体积高压釜内,于333,353,373和393K等4个温度下,测定了3.0~15.0MPa范围内超临界CO2与碳酸二乙酯(DEC)二元体系的气-液平衡数据.结果表明,当温度恒定时,随着压力的增大,液相中超临界CO2的浓度急剧增大,气相中碳酸二乙酯的浓度缓慢增加.根据实验结果推测出了体系的pc,Tc,xc和Vc等临界性质.  相似文献   

10.
The solvent strength and selectivity of supercritical fluids (SCF) can be greatly enhanced by addition of one or two entrainers into the system. The amount of entrainer added is usually less than 5% (mole fraction). However, even with such slight amount, solubility of organic solutes has been observed to increase by several orders magnitude[1]. Therefore, critical pressure and tem-perature data of these supercritical fluid + cosolvent systems are imperative for the reasonable design of effici…  相似文献   

11.
The system LaPO4-Ca2P2O7-Ca(PO3)2-La(PO3)3 was investigated by means of thermal and X-ray analyses. Three binary systems were found to occur in this region: LaPO4-Ca(PO3)2,LaPO4-Ca4P6O19 and LaPO4-CaLa(PO3)5. Their phase diagrams, and also that for the system LaPO4-Ca2P2O7- Ca(PO3)2-La(PO3)3, were obtained. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

12.
First Binary Mixture Ionic Liquids Containing EMIMBr and IM   总被引:1,自引:0,他引:1  
A new series of binary mixture ionic liquids comprising 1-ethyl-3-methylimidozalium bromide(EMIMBr) and imidazole(IM) have been synthesized.The melting prints of the ionic liquids vary with te different content of IM while they still keey satisfactory conductivity and viscosity.According to the analysis of its phase diagram,the cutectic point is about 16.5℃ with the mass percentage of IM 29%.  相似文献   

13.
采用等温溶解法研究了三元体系H3BO3 - MgCl2 - H2O在308.15 K和323.15 K的稳定相平衡;测定了上述体系液相中各组分的平衡溶解度及液相密度,并绘制了相应相图和平衡溶液密度组成图.结果表明,该体系在308.15 K和323.15 K时有一个共饱点、两条饱和溶解度曲线和两个结晶相区,无复盐及固溶体...  相似文献   

14.
Experimental data on the adsorption of Ar, Kr, Xe, CH4, and CF3Cl on zeolite NaX and of CH4 on PAU-10 carbon demonstrate that the linear temperature range dependences of the equilibrium matched standard values of lnp i,st and ln , which are used in the calculation of adsorption equilibria in a subcritical temperature range, remain unchanged up to temperaturesT *T cr+(100÷150).Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1668–1670, September, 1993.  相似文献   

15.
A model to describe vapor-liquid equilibrium (VLE) and solid-liquid equilibrium (SLE) in the ammonia-phosphoric acid-water system is developed. The model takes into account chemical reactions as well as physical interactions. Using interaction parameters and solubility contants as determined from experimental data on VLE and SLE, the model is capable of describing the phase behavior in this extremely complex system over a wide range of composition.Dedicated to Prof. Dr.-Ing. G. Ernst on the occasion of his 60th birthday.  相似文献   

16.
Study of solid-liquid phase diagram of LiPO3-Pb(PO3)2 binary system, in certain calcination conditions, shows the existence of several metastable phasis. When heated at a temperature of 723 K the binary mixtures lead uncompletely to a defined compound Pb2Li(PO3). On heating these ternary solid mixtures, three eutectic reactions have been observed: LiPO3+Pb(PO3)2→Liquid at a temperature of 793 K(1) LiPO3+Pb2Li(PO3)5→Liquid at a temperature of 843 K (2) Pb2Li(PO3)5+Pb(PO3)2→Liquid at a temperature of 891 K (3) The metastable liquid phase appears in the system at temperature of 793 K. DTA experiments performed on the binary LiPO3-Pb(PO3)2 mixtures, show a superposition of two diagrams. The first one is metastable and the second represents the stable equilibrium phase diagram. Measurements of liquid enthalpy of binary LiPO3-Pb(PO3)2 system at temperature of 979.65 K were reported. The corresponding values were very small and so the binary system can be considered as athermal. Assuming an ideal behaviour, the liquidus curves in the metastable diagram were calculated and the eutectic reaction (LiPO3-Pb(PO3)2→Liquid) was confirmed at 793 K. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

17.
钒和磷都是动植物体中的必需元素,在动植物体中起着十分重要而又非常复杂的生理作用。土壤中的钒、磷等元素可通过食物链进入生物体或植物体中,对动植物体都带来一定的影响。适量的钒能促进植物的生长发育,促进植物的固氮、固氯作用;钒累积达到一定程度时,则会对动植物体产生一定的毒理作用。影响动植物体内酶的活性调节、蛋白质的生物合成及遗传过程。  相似文献   

18.
Multicomponent systems may exhibit several critical points or no critical point at all. Local methods can find only one critical point for a given initial guess. Recently, several global methods have been proposed for finding all the solutions of the problem. In the present work, we propose a gradient-based calculation method using global optimization, with temperature and molar volume as primary variables, and with analytical partial derivatives calculated from a two-parameter cubic equation of state. The Tunneling global optimization method is used for finding all the global minima. The implementation is based on a unique feature of the Tunneling method, which is able to find efficiently and reliably multiple minima at the same level. Several mixtures from binaries to petroleum reservoir fluids are used to test the proposed method. Numerical experiments proved the efficiency and reliability of the Tunneling method for finding all mixture critical points.  相似文献   

19.
我国西藏的扎布耶盐湖卤水以富含硼、锂、钾而闻名于世[1-2]。依据扎布耶盐湖卤水体系的主要成分,该卤水体系可简化Li K Na B4O72- CO32- Cl- SO42- H2O体系。针对西藏盐湖地处干旱、强日照特点,开展对扎布耶盐湖卤水体系的多温稳定及介稳相平衡研究,对于解释盐湖的演化及指  相似文献   

20.
采用等温蒸发平衡法研究了四元体系K2B4O7-Na2B4O7-Li2B4O7-H2O在273 K时的介稳相平衡及平衡液相的密度. 研究发现该四元体系为简单共饱和型, 无复盐及固溶体形成, 根据溶解度数据绘制了相图, 相图中有一个共饱点E, 三条单变度曲线E3E, E2E, E1E; 三个平衡固相分别为K2B4O7·4H2O、Na2B4O7·10H2O 和LiBO2·8H2O. 并简要讨论了实验结果.  相似文献   

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