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采用高效液相色谱法测定了常压下在293.15~323.15 K温度范围内反式-4-羟基环己基地氯雷他定在水、质量分数为10% 的甲醇-水、质量分数为20% 的甲醇-水、质量分数为10% 的乙醇-水和质量分数为20% 的乙醇-水中的溶解度,并采用Apelblat方程和λh方程对所得到的溶解度数据进行关联拟合,通过van't Hoff方程计算了其在不同溶剂中的溶解焓和溶解熵。发现反式-4-羟基环己基地氯雷他定的溶解度随着温度的升高和溶剂极性的降低而升高,其溶解过程在实验温度范围内,在所选溶剂中均为吸热熵增过程。 相似文献
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阿维菌素在不同醇-水溶剂体系中溶解度的测定与关联 总被引:1,自引:0,他引:1
工业生产中阿维菌素在不同比例的有机溶剂-水体系中的溶解度是重要的基础数据,本实验采用平衡法测定了阿维菌素在甲醇含量100%~70%、乙醇含量100%~60%的水溶剂中,温度范围为30~70℃的溶解度,并采用多项式经验方程、半经验关联模型对实验测定溶解度数据进行关联,相关系数都在98%以上,结果较为满意。结果表明在甲醇-水溶剂体系中随水的比例增加,溶解度减少较为明显,以32℃时为例,90%甲醇-水溶剂比纯甲醇做溶剂的溶解度下降了67%,而乙醇-水体系随水的比例增加,溶解度减小较缓和,同样条件下,在95%乙醇-水溶剂中溶解度只下降了28%。 相似文献
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《化学工程》2021,49(9)
在288.15—308.15 K的温区范围内,通过称量法测定了常压下2-金刚烷酮在甲醇、乙醇、乙腈乙酸、乙酯4种溶剂中的溶解度,并采用Apelblat方程、λ-h方程以及多项式拟合的方法对所测定溶解度数据进行关联,利用Polythermal法测定了2-金刚烷酮在4种溶剂中的冷却结晶介稳区宽度。实验得出2-金刚烷酮在4种溶剂中溶解度都具有正温度系数,在甲醇、乙醇中的温度系数大于其在乙腈、乙酸乙酯中的温度系数,3种溶解度模型均得到了较好的关联系数;2-金刚烷酮在乙酸乙酯中的介稳区最宽且稳定,根据晶体生长条件,初步判定在甲醇、乙酸乙酯中分别用降温法和恒温蒸发法可以长出单晶。 相似文献
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《火炸药学报》2015,(6)
在大气压力及298.15~338.15K下采用激光动态法测定了3,4-二硝基呋咱基氧化呋咱(DNTF)在不同体积比的乙酸-水混合溶剂中的溶解度,用Apelblat和(CNIBS)/Redlich-Kister经验模型对溶解度数据进行拟合,根据溶解度实验数据估算了DNTF的标准溶解焓、标准溶解熵、标准吉布斯自由能、固-液表面张力以及表面熵因子。通过测定DNTF在乙酸-水混合溶剂中的超溶解度,得到DNTF的冷却结晶介稳区,探讨了溶剂组成和温度对溶解度的影响。结果表明,用Apelblat模型和(CNIBS)/Redlich-Kister模型计算的溶解度值与实验值的平均相对误差分别为1.698%和3.001%;DNTF在乙酸-水溶液中的溶解度随温度的升高和乙酸含量的增加而增大;介稳区宽度随温度的增加而变宽,随乙酸含量的增大而变窄。 相似文献
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Isobaric vapor-liquid equilibrium(VLE) data for acetic acid+sec-butyl acetate and water+acetic acid+sec-butyl acetate systems were determined at 101.3 kPa using a modified Rose type. The nonideality of the vapor phase caused by the association of the acetic acid was corrected by the chemical theory and Hayden-O’Connell method. Thermodynamic consistency was tested for the binary VLE data. The experimental data were correlated successfully with the Non-Random Two Liquids (NRTL) model. The Root Mean Square Deviation (RMSD) of the ternary system was 0.0038. The saturation vapor pressure of sec-butyl acetate at 329 to 385 K was measured by means of two connected equilibrium cells. The vapor pressures of water and sec-butyl acetate were correlated with the Antoine equation. The binary interaction parameters and the ternary VLE data were obtained from this work. 相似文献
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The knowledge of solubility of a salt in either the pure solvent or blend solvent is of great importance for studying or operating the crystallization, extraction, and distillation processes. The solubility of sodium acetate (NaAc) in four pure solvents (water, ethanol, acetic acid and 2,2,2-trifluoroethanol) and four binary solvents (water–ethanol, water-acetic acid, acetic acid–ethanol, and acetic acid-ethyl acetate) were measured by using the laser dynamic method at temperatures from 288.15 K to 338.15 K at 0.1 MPa. The results showed that the solubility of NaAc was influenced by either the solution temperature or solvent composition. The aqueous sodium acetate solution possessed the maximal solubility under the experimental conditions. The solubility of NaAc in 2,2,2-trifluoroethanol was found to be decreased with the increase of the solution temperature. While, the solubilities of NaAc in other seven solvents increased as the solution temperature was elevated. Besides, five correlation models, including the van't Hoff model, modified Apelblat model, Yaws model, λh model, and modified Apelblat-Jouyban-Acree model were used to correlate the solubility data of those sodium acetate solutions with acceptable deviation, respectively. Finally, van't Hoff analysis method was selected to analyze the change law of thermodynamic properties of a salt during the dissolution process. 相似文献
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《Chemical engineering journal (Lausanne, Switzerland : 1996)》2001,81(1-3):271-279
The results of an investigation aimed at obtaining the kinetic characteristics of the hydrolysis reaction of phenyl acetate catalysed by sodium acetate are presented. The hydrolytic reaction giving phenol and acetic acid starting from phenyl acetate is particularly suitable to run in a microwave-irradiated environment. In fact, since the considered reaction is characterised by a very low rate, small variations occurring in an irradiated system can be detected. Furthermore, since this reaction runs in an aqueous environment, it can use the energy transmitted by microwave radiation efficiently, thanks to the high capacity of water absorbance at microwave frequencies. The reaction was run in a buffered aqueous solution of sodium acetate and acetic acid at equal concentrations (pH=5). Kinetic constants were obtained in the 293–318 K temperature interval and at a concentration of both sodium acetate and acetic acid in the 0.4–0.06 mol dm−3 range. The derived activation energies decreased as the concentration of the sodium acetate/acetic acid increased. The kinetic study of the hydrolysis was carried out to obtain experimental data suitable for a fast comparison with the data that will be obtained from the development of this reaction in a microwave-irradiated environment. This paper also presents the analytical and experimental techniques suitable to run the experimental procedure in a microwave-irradiated reactor. 相似文献
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1,2-环己二醇在溶剂中的溶解度 总被引:1,自引:0,他引:1
1 INTRODUCTION The solubility of solid in liquids is an excellent tool to investigate solute-solvent intermolecular forces in the liquid state. In this work the solubility of trans-1,2-cyclohexanediol in some polar solvents (wa- ter, methyl acetate, acetic ester, propyl acetate, butyl acetate, methyl acrylate, and ethyl acrylate) was mea- sured at temperatures ranging from about 300 K to 330 K, using a modification of the experimental tech- nique of laser monitoring observation system. So… 相似文献
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Esterification of methyl alcohol with acetic acid catalysed by Amberlyst-15 (cation-exchange resin) was carried out in a batch reactor in the temperature ranging between 318-338 K, at atmospheric pressure. The reaction rate increased with increase in catalyst concentration and reaction temperature, but decreased with an increase in water concentration. Stirrer speed had virtually no effect on the rate under the experimental conditions. The rate data were correlated with a second-order kinetic model based on homogeneous reaction. The apparent activation energy was found to be 22.9kJmol-1 for the formation of methyl acetate. The methyl acetate production was carried out as batch and continuous in a packed bed reactive distillation column with high purity methyl acetate produced. 相似文献
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Jae-Kyeong Kim Han-Sang Oh Chang-Wha Jo Yong-Jae Suh Hee-Dong Jang Kee-Kahb Koo 《Chemical Engineering Research and Design》2010
This paper describes the recovery process of iron as a form of ferrous acetate from low-grade magnetite ore (Shinyemi Mine, Gangwon province, Korea). The magnetically separated magnetite powder was dissolved in aqueous oxalic acid solution. The dissolution fraction of magnetite concentrates was measured as a function of initial pH, reaction temperature and oxalic acid concentration. Optimum conditions for dissolution of magnetite ore were the temperature higher than 90 °C, pH 1 and oxalic acid concentration 0.5 M. Addition of aqueous H2O2 solution oxidized ferrous ion of iron-containing solution. And then, at pH 4, ferric hydroxide was precipitated from iron-containing solution by the addition of NaOH aqueous solution. Ferrous acetate was prepared from the reaction between ferric hydroxide and acetic acid/acetic anhydride mixture and quantitatively characterized by ICP-AES, XRD, SEM, FT-IR and XPS. Purity of ferrous acetate was found to be 91.88% with other impure elements such as Na, Ca, K, Mg and Al by ICP-AES and XPS analysis. XRD and SEM analysis showed that as-prepared ferrous acetate in the present experiments was in low crystalline state. FT-IR spectra confirmed the presence of free acetate ions and monoacetato bidentate structure in as-prepared ferrous acetate. 相似文献
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In this work, esterification of acetic acid and methanol to synthesize methyl acetate in a batch stirred reactor is studied in the temperature range of 305.15–333.15 K. Sulfuric acid is used as the homogeneous catalyst with concentrations ranging from 0.0633 mol·L?1 to 0.3268 mol·L?1. The feed molar ratio of acetic acid to methanol is varied from 1:1 to 1:4. The influences of temperature, catalyst concentration and reactant concentration on the reaction rate are investigated. A second order kinetic rate equation is used to correlate the experimental data. The forward and backward reaction rate constants and activation energies are determined from the Arrhenius plot. The developed kinetic model is compared with the models in literature. The developed kinetic equation is useful for the simulation of reactive distillation column for the synthesis of methyl acetate. 相似文献
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Using a laser observation technique,the solubilities of trans-1,2-cyclohexanediol in butyl acetate+wa- ter were measured at the temperature range from 298.15K to 323.15K by a synthetic method at atmospheric pres- sure.It is shown that the solubilities of trans-1,2-cyclohexanediol in butyl acetate+water were affected greatly by the proportion of butyl acetate and water,and presented maximum value at given temperature.The UNIFAC model was used to correlate the experimental data.The average relative deviation(ARD)between experimental and calculated values is 3.03%. 相似文献