微反应器内苯二硝化反应过程研究  

Study on the Process of Benzene Dinitration in a Microreactor

作　　者：居雨凡 廉应江 杨梅[1] 陈光文[1] JU Yufan;LIAN Yingjiang;YANG Mei;CHEN Guangwen(Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian 116023,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院大连化学物理研究所,辽宁大连116023 [2]中国科学院大学,北京100049

出　　处：《化学反应工程与工艺》2023年第1期45-52,共8页Chemical Reaction Engineering and Technology

基　　金：国家自然科学基金重大项目(21991103);国家自然科学基金面上项目(22178336)。

摘　　要：以硝硫混酸为硝化剂,研究了微反应器内苯二硝化反应过程的规律。实验考察了原料计量比、反应温度、硝硫物质的量比、进料流量以及混酸含水量对苯转化率及产物选择性的影响。结果表明:提高硝酸与苯的物质的量比和反应温度,或降低硝硫物质的量比和混酸含水量有利于二硝基苯生成;提高进料流量时,二硝基苯选择性先降低后升高。微反应器与搅拌釜串联使用可显著降低硝基苯选择性。在硝酸与苯的物质的量比为2.30、反应温度为80℃、硝硫物质的量比为0.5、混酸含水量为2%(质量分数)、苯流量为0.6 mL/min、混酸流量为2.60 mL/min、微反应器内停留时间为135 s的条件下,搅拌10 min可将硝基苯选择性由0.643%降低至0.002%,此时苯的转化率为99.970%,二硝化产物总选择性为99.998%,其中间二硝基苯选择性为83.292%。研究结果为开发间二硝基苯的连续制备工艺提供了技术支持。Benzene dinitration in a microreactor was studied using mixed acid as nitration agent.The effects of molar ratio of nitric acid to benzene,reaction temperature,HNO3/H2SO4 molar ratio,feed flow rate and water content in mixed acid were investigated.It was found that increasing the molar ratio of nitric acid to benzene and reaction temperature,or decreasing the HNO3/H2SO4 molar ratio and water content in mixed acid could improved the formation of dinitrobenzene,while the selectivity of dinitrobenzene first decreased and then increased with the increase of feed flow rate.The combination of microreactor and stirred tank could decrease the selectivity of nitrobenzene significantly.When molar ratio of nitric acid to benzene of 2.30,reaction temperature was 80℃,HNO3/H2SO4 molar ratio was 0.5,water mass fraction in mixed acid of 2%,benzene flow rate was 0.6 mL/min,mixed acid flow rate was 2.60 mL/min and the residence time in the microreactor was 135 s,further reacting 10 min in the stirred batch reactor reduced the selectivity of nitrobenzene from 0.643%to 0.002%.At this condition,the benzene conversion was 99.970%,and the total selectivity of dinitration products was 99.998%with the selectivity of m-dinitrobenzene of 83.292%.The study provided technical support for the development of continuous synthesis process of m-dinitrobenzene from benzene.

关 键 词：微反应器 硝化反应 苯 二硝基苯 

分 类 号：TQ031.6[化学工程]