摘要
以氯苯为原料,采用静态混合反应技术连续制备了2,4-二硝基氯苯.用Chemcad流程模拟软件模拟了氯苯硝化过程的绝热温升,得到具有本质安全性的混酸组成范围为：w（硝酸）=3％～25％,w（硫酸）=45％～75％,w（水）=0～30％.研究表明：混酸组成、空时、保温温度、流速对静态混合管式连续硝化均有影响;流速对于静态混合器发挥出良好的混合效果起决定性作用.通过响应面实验设计优化了工艺条件：反应预热温度50℃,反应压力0.15 MPa,保温温度为75℃,硝化比为2.1,混酸组成为m（硫酸）∶m（硝酸）∶m（水）=0.7∶0.19∶0.11,流速为0.062 m/s,空时为3.5 min;在该工艺条件下,氯苯转化率为97.26％,2,4-二硝基氯苯选择性为85.93％,2,4-二硝基氯苯的收率83.58％;与传统间歇操作相比收率略有提高,明显缩短了反应周期,降低了物耗,减少了NOx在空中逸散引起的环境污染,反应条件安全性更高.
2,4-dinitrochlorobenzene was continuous prepared using static mixing reaction technique with chlorobenzene as material.Chemcad process simulation software was used to simulate the adia batic temperature rise of chlorobenzene nitration process.The safety range of composition of mixed acid for the scientific research and industrial production was obtained as that nitric acid was 3％ to 25％,sulfuric acid was 45％ to 75％ and water was 0 to 30％.Further study was made on the basis of the research.The results show that the all the factors as composition of mixed acid,space time,holding temperature and flow velocity have effects on the static mixing tube continuous nitrification.The effect of velocity on static mixer played a decisive role.Process condition was optimized by response surface design of experiment.The suitable process conditions were that preheating temperature was 50 ℃,the reaction pressure was 0.15 MPa,holding temperature was 75 ℃,nitrification ratio was 2.1,m（mixed acid of sulphuric acid） ∶ m（nitric acid） ∶ m（water） =0.7 ∶ 0.19 ∶ 0.11,the velocity was 0.062 m/s and space time was 3.5 min.Under these conditions,chlorobenzene conversion was 97.26％,2,4-dinitrochlorobenzene selectivity was 85.93％ and 2,4-dinitrochlorobenzene yield was 83.58％.Compared with the traditional batch process,the yield was slightly increased,the reaction cycle was significantly shortened,material consumption was lowered,environmental pollution caused by the escape of NOx was reduced and the security of reaction conditions was enhanced.
出处
《精细石油化工》
CAS
CSCD
北大核心
2014年第2期20-24,共5页
Speciality Petrochemicals
基金
沈阳市科技计划项目(1091036-4-00)
沈阳市科技计划项目(F12-188-9-00)
关键词
静态混合器
2
4-二硝基氯苯
绝热温升
流速
static mixer
2, 4-dinitrochlorobenzene
adiabatic temperature rising
flow velocity
