文献类型：期刊文献

中文题名：连四甲苯液相氧化过程热力学分析及动力学模拟

英文题名：Thermodynamic analysis and kinetic simulation of liquid phase oxidation of prehnitene to mellophanic acid

作者：吕全明[1];孙伟振[1];赵玲[1,2]

机构：[1]华东理工大学化学工程联合国家重点实验室,上海200237;[2]新疆大学化学化工学院,新疆乌鲁木齐830046

年份：2021

卷号：72

期号：2

起止页码：1009

中文期刊名：化工学报

外文期刊名：CIESC Journal

收录：CSTPCD;;Scopus;北大核心:【北大核心2020】；CSCD:【CSCD2021_2022】；

基金：国家自然科学基金项目(91434108)。

语种：中文

中文关键词：连四甲苯;苯偏四甲酸;基团贡献法;热力学分析;动力学

外文关键词：prehnitene;mellophanic acid;group-contribution;thermodynamic analysis;kinetics

摘要：连四甲苯(PR)液相氧化制备苯偏四甲酸(MPA)是合成聚偏苯四甲酰亚胺单体的关键步骤。本文首先采用基团贡献法对MPA的热力学参数进行了估算,进一步分析了PR氧化过程热力学参数随温度的变化。结果表明,在研究温度范围内,该氧化过程为强放热反应,反应过程中需要及时移除反应热以控制温度的波动。通过间歇实验研究了不同催化剂浓度和温度对反应的影响,动力学实验结果表明,保持催化剂总浓度不变,改变催化剂配比对PR氧化速率影响不大,但是提高Mn浓度对MPA生成速率的提升效果最佳;升高温度能够明显提升目标产物MPA的选择性。基于自由基链式反应机理,建立了简化的PR氧化集总动力学模型,拟合回归得到苯环上首个甲基氧化的活化能为57.20 kJ·mol-1;但是苯环上部分甲基被氧化为羧基后,其他甲基氧化的活化能增加为120.30 kJ·mol-1,说明羧基的存在使甲基活性变弱,被进一步氧化的难度增加。论文相关研究成果可为MPA生产新工艺的开发和工业反应器设计提供参考依据。
The liquid phase oxidation of prehnitene(PR)to mellophanic acid(MPA)is a key step in the synthesis process of polyimide monomers.In this work,thermal properties of PR liquid phase oxidation were calculated,in which the thermodynamic parameters of MPA were estimated by group contribution methods.The results show that this reaction is a strong exothermic reaction within the studied temperature range,thus the reaction heat should be carefully controlled during the reaction process.Then the optimal reaction conditions were determined by batch experiments in the ranges of 200—240℃,and a lumped kinetics model under different temperatures,catalyst concentrations and ratios were established.It is found that the catalyst ratio of Co/Mn/Br has a great influence on the generation rate of MPA,while little on the oxidation rate of PR.Particularly,the increase of Mn content has the best effect on the increase of MPA generation rate.Simultaneously,the increase of temperature can significantly accelerate the rate of PR oxidation with an activation energy of 57.20 kJ·mol-1.However,the activation energy of other methyl groups increased to 120.30 kJ·mol-1 when part of methyl groups on the benzene ring were oxidized to carboxyl groups,indicating that the existence of carboxyl groups can weaken the activity of methyl groups and increase the difficulty of further oxidation.The related research results of the thesis can provide references for the development of new MPA production processes and the design of industrial reactors.