摘要
为实现二硝基甲苯(DNT)的安全高效生产,采用微反应技术,以甲苯为原料、硝硫混酸为硝化剂,研究了甲苯连续二硝化反应过程基本规律。提高反应温度、增大硝酸与甲苯的摩尔比、降低混酸含水量、减小硝硫摩尔比、集成釜式搅拌操作有利于DNT的生成;降低反应温度、提高混酸含水量和硝硫摩尔比,有利于降低2,4-/2,6-DNT比值。针对80/20DNT产品进行了硝化工艺优化。在反应温度75℃、混酸含水量14%(质量分数)、硝硫摩尔比1/4或1/3、搅拌时间5 min条件下,产物中一硝基甲苯(MNT)含量小于0.2%,2,4-和2,6-DNT含量大于96%,2,4-/2,6-DNT比值小于4.25,其他DNT异构体含量均小于4%,符合行业标准。绝热条件下,室温进料,混酸含水量14%(质量分数),硝硫摩尔比1/4,搅拌时间10min,生产的产品质量符合行业标准。研究结果为甲苯连续二硝化工艺开发及80/20DNT产品的连续制备提供了基础。
In order to realize the safe and efficient production of dinitrotoluene(DNT),the behavior of toluene dinitration process was investigated by using microreaction technology with mixed acid as nitrating agent and toluene as raw material.Increasing the reaction temperature,elevating the molar ratio of nitric acid to toluene,reducing the water content of the mixed acid and decreasing N/S and integrating stirring were all conducive to the generation of DNT.Lowering the reaction temperature and increasing the water content of the mixed acid and the molar ratio of nitrate to sulfur are beneficial to reducing the 2,4-/2,6-DNT ratio.The nitrification process has been optimized for 80/20DNT products.At a reaction temperature of 75℃,a water content of mixed acid of 14%,N/S of 1/4 or 1/3,and a stirring time of 5 min,the product composition demonstrated desirable characteristics,i.e.,the content of MNT in the product was less than 0.2%,2,4-DNT and 2,6-DNT greater than 96%and other DNT less than 4%.More importantly,the ratio of 2,4-/2,6-DNT was less than 4.25.Under the conditions of adiabatic and room temperature feeding,a mixed acid water content of 14%,N/S of 1/4,and stirring time of 10 min,the product also complied with the industry standards.The study outcomes offer valuable technical insights for the continuous dinitration process of toluene and the continuous preparation of 80/20DNT products.
作者
陈饶
赵鑫
陈戴欣
姜圣坤
廉应江
王金波
杨梅
陈光文
CHEN Rao;ZHAO Xin;CHEN Daixin;JIANG Shengkun;LIAN Yingjiang;WANG Jinbo;YANG Mei;CHEN Guangwen(Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian 116023,Liaoning,China;University of Chinese Academy of Sciences,Beijing 100049,China;China Wuzhou Engineering Group,Beijing 100053,China)
出处
《化工学报》
EI
CSCD
北大核心
2024年第3期867-876,共10页
CIESC Journal
基金
国家自然科学基金项目(21991103)。
关键词
微反应器
微通道
过程强化
硝化
二硝基甲苯
microreactor
microchannel
process intensification
nitration
dinitrotoluene
