【作者】 吴舰；

【导师】 李斌栋；

【作者基本信息】 南京理工大学 ， 应用化学， 2012， 硕士

【摘要】 芳烃硝化一直存在强放热、安全性差、环境污染等问题,利用新兴的微反应器技术,以其极大的比表面积、微小的反应体积和优良的传热传质性能,实现对芳烃硝化的精确控制。本文以特殊的微玻璃反应器为核心,完成微反应系统的建立,应用于芳烃硝化研究。(1)在微反应系统内,重点探索以硝酸为硝化剂甲苯硝化工艺研究。在优化工艺条件下对比常规反应器,反应时间缩短至原来的1/100,甲苯转化率提高到94.8%,一硝化选择性在99.4%以上,而邻/对比(o/p值)控制在1.29-1.34。在此基础上将其应用于其他芳烃的硝化,得到优于常规反应器的芳烃转化率和硝化选择性,证明了该系统的普适性,并从工艺评价的角度总结微反应系统应用于芳烃硝化的优势。(2)将均相催化体系与微反应系统结合,重点从反应转化率、异构体选择性和体系的循环催化等角度研究简单芳烃的绿色硝化。在离子液体催化体系下,甲苯转化率达到94%,o/p值降为1.25；经五次循环利用,转化率仍在88%以上,o/p值小于1.30；对比常规反应器,烷基苯转化率提高到90%以上,卤代苯转化率提高10%以上。在三氟乙酸镧系盐催化体系下,甲苯转化率达到90%左右,o/p值降为1.27；经五次回收,催化剂的质量损失小于5%,转化率始终大于88%,o/p值控制在1.30以下；对比常规反应器,烷基苯和卤代苯转化率分别提高15%和10%以上,同时烷基苯对位产物和卤代苯邻位产物分别提高5%左右。从NO2+理论出发,探讨了上述催化硝化反应机理,完成微反应器内芳烃绿色硝化与选择性硝化研究,具有理论和工程实践指导意义。更多还原

【Abstract】 Aromatic nitration has always been a highly exothermic reation, poor safety and environment pollution. Using the novel microreactor technology, with its great specific surface area, small volume and excellent heat and mass transfer performance, we realized the precise control of aromatic nitration. The article based on the special microglass reactor as the core, established the microreaction system, which used in the aromatic nitration research.(1)Using nitric acid as nitrating agents, we detailedly studied on the nitration process of toluene in the microreactor system. By compared with the date obtained from the conventional reactor, in the optimization of conditions, the reaction time was shortened to 1/100, the conversion of toluene came up to 94.8%, the selectivity of mono-nitration was improved to 99.4%, the ortho-/para-(o/p) ratio was controlled in 1.29～1.34. Its applications in nitration of other simple aromatics showed that conversion and selectivity were superior to the conventional reactor, which proved the universality of the system. From the perspective of process evalution, we summarized the advantages of microreactor system applied in the aromatic nitration.(2)Introducing the homogeneous catalysts into the microreactor system, from the perspectives of conversion, reaction selectivity and the cycle catalytic system, we emphasised on the nitration of simple aromatics. In ionic liquids catalytic system, the conversion of toluene reached 94%, o/p ratio reduced to 1.25. After five recycling, the conversion of toluene was still above 88% and o/p ratio was less than 1.30. By compared to conventional reactor, the conversion of alkyl-benzenes increased to 90%, the conversion of halogenated-benzenes increased by more than 10%. In Lanthanide(iii) trifluoroacetate catalytic system, the conversion of toluene kept to 90%, o/p ratio reduced to 1.27. The conversion of alkyl-benzenes and halogenated-benzenes were increased about 15% and 10% versus batch reactor, while the para-selectivity of alkyl-benzenes and the ortho-selectivity of halogenated-benzenes were improved about 5% versus without catalysts. Finally, based on NO2+ theory, the article simply discussed the catalytic mechanism of nitration, completed the green nitration and regioselective mono-nitration of aromatics in the microreactor system, had theoretical and engineering practical significance.更多还原