【作者】 陈明鸣；

【导师】 马沛生；

【作者基本信息】 天津大学 ， 化学工艺， 2003， 博士

【摘要】 对苯二甲酸生产中相关相平衡的测定与研究学 院：化工学院专业：化学工艺指导教师：马沛生 教授六级英语证书：有研 究 生：陈明鸣，于1997年4月在天津大学获工学硕士学位为了给设计单位提供有关对苯二甲酸（TA）生产中的相平衡数据，本文着重实验测定并以数学模型描述了以下两方面内容：TA和TA生产中的主要杂质在相关溶剂中的固液平衡，以及对二甲苯（PX）氧化反应器的溶剂体系醋酸-PX的汽液平衡。针对本文所涉及的固液平衡体系中，溶质溶解度微小的特点，对已有的合成法测定固液平衡装置进行了改进并建立了新装置，通过改变搅拌方式和平衡判断标准，在简化操作、增加可靠性的同时，提高了数据精度；实验测定了TA、对甲基苯甲酸（PT-acid）和对羧基苯甲醛（4-CBA）在醋酸、水、不同浓度的醋酸水溶液、N,N-二甲基甲酰胺、N,N-二甲基乙酰胺、二甲亚砜和N-甲基-2-吡咯烷酮中的溶解度数据，共涉及9个二元物系和5个三元体系，温度范围覆盖288.25 K ~ 444.85K。选用一般相平衡理论中的Wilson方程、Wilson-T方程（Wilson方程中的参数与温度相关联）、λh方程、UNIFAC法和修正UNIFAC法计算了所测定体系的固液平衡数据，并给出相关的模型参数。在UNIFAC法和修正UNIFAC法中定义了新基团TA、PT-acid和4-CBA。研究表明，λh方程和将常温段与高温段分开计算的修正UNIFAC法的计算精度较好，平均相对偏差低于2.5%；而且总体来说，将方程参数考虑为温度的函数的方法均优于认为参数与温度无关的方法。在预测含醋酸三元体系的固液平衡时，修正UNIFAC法的偏差较大。这证明，一般的相平衡理论在描述含有强相互作用体系的非理想性时有所欠缺。因<WP=3>此，本文由化学理论出发，将缔合引入含醋酸体系的固液平衡计算过程中，发现效果很好。同时，给出了液相缔合平衡常数与温度的关系，证明了液相中的醋酸在温度较低时，缔合严重。自行设计并安装了一套泡露点法测定加压条件下汽液平衡的装置，纯物质饱和蒸气压的测定值与Antoine方程的计算值的比较结果证明该装置可靠。测定了140℃、150℃和160℃下并加压下，醋酸-PX体系的二元汽液平衡，数据通过了热力学一致性的积分和微分校验。定义了新基团PX，并采用修正UNIFAC法、Wilson模型和NRTL模型分别回归了二元汽液平衡数据，并给出相应的模型参数，三者的精度均较高，平均相对偏差小于3%。更多还原

【Abstract】 In order to give sufficient data support for the design of terephthalic acid (TA) manufacture, corresponding phase equilibria, including solid-liquid equilibrium (SLE) and vapor-liquid equilibrium (VLE), have been determined and studied.Improvements have been made on our former apparatus, which was used for the measurement of solid solubility, for the purpose of getting more precise experimental data in the range of lower solubility. Horizontal stir was changed to magnetic whirly one, which shortened the dissolving time remarkably. Moreover, judgement criterion for phase equilibrium was moved to the time when the transmitted laser light intensity during stirring is equal to that without stirring, which is more reasonable than the former criterion that named equilibrium only when the transmitted laser light intensity performs the highest one. With TA, p-toluic acid (PT-acid), 4-carboxyl-benzaldehyde (4-CBA) as solutes, water, acetic acid, aqueous acetic acid of several concentration, N,N-dimethylformamide, N,N-dimethylacemide, dimethyl sulphoxide, N-methl-2-ketopyrolidine as solvents respectively, SLE of 9 binary systems and 5 ternary systems were determined over the temperature range from 288.25 K to 444.85K. General phase equilibrium theories, including Wilson equation, Wilson-T equation (parameters in Wilson equation were associated to temperature), λh model, UNIFAC method and modified UNIFAC method, have been chosen to study SLE of all the 9 binary systems and the corresponding model parameters were given. New groups, such as TA, PT-acid and 4-CBA were defined for UNIFAC method and modified UNIFAC method. The average relative errors of modified UNIFAC method, which treated the solubility of TA in acetic acid separately in two regions split according to temperature, and λh model were below 2.5%, which means they were more suitable for SLE of the systems abovementioned than the other activity coefficient equations. It was also found that better correlation of the experimental data was obtained if all the interaction parameters were treated as function of temperature. Unsatisfactory prediction of the ternary systems with general phase equilibrium<WP=5>theories showed that those theories are insufficient to describe the system containing acetic acid that have strong interaction between molecules. Thus, chemical theory together with association was introduced. This method performed very well. The relationship between association constant and temperature was presented which demonstrated that there was severe association among acetic acid molecules in liquid phase at lower temperature.A set of new apparatus for determining VLE at high pressure based on the principle of bubble-dew method has been designed and established. And the reliability of this equipment was verified by comparison of determined saturated pressure of pure substances with the ones calculated by Antoine equation. At certain temperature of 140℃, 150℃ and 160℃, VLE of acetic acid-PX binary system was determined. VLE data were tested through thermodynamic consistency by both integrate and differential methods. Wilson model, NRTL model and modified UNIFAC method with new defined group PX were used to study the VLE, and model parameters were listed.更多还原