微通道中硝基胍的连续流合成

Continuous Synthesis of Nitroguanidine in Micro-channel Reactor

以硫酸胍和硝硫混酸为原料,在微通道中进行管式流动硝化反应。考察了混酸浓度、反应温度、停留时间、物料比对反应的影响。获得的优化工艺参数为:V(质量分数80%HNO_3)∶V(质量分数98%H_2SO_4)=2∶1,n(硫酸胍)∶n(硝酸)=1∶1.2,反应温度为60℃,停留时间为30 s,此时硫酸胍的转化率为87.9%,硝基胍收率为86.1%。与传统间歇釜式合成工艺相比,连续流工艺实现了硝基胍合成反应的稳定进行,消除了过程反应热的积累和温度波动,缩短反应时间。

Nitration of guanidine was carried out in a continuous flow micro-channel reactor using guanidine sulfate as a raw material,and nitric acid and sulfuric acid mixture as a nitrating agent. The influences of the mixed acid concentration,reaction temperature,residence time and ratio of two materials on the yield of nitroguanidine were investigated. The optimal reaction conditions were shown as follows： V（ mass fraction 80% HNO3） ∶V（ mass fraction 98% H_2SO_4） = 2∶1,molar ratio of guanidine sulfate and HNO3 1 ∶ 1. 2,reaction temperature at 60 ℃,residence time of 30 s. Under the above conditions,the conversion of guanidine sulfate and the yield of nitroguanidine reached 87. 9% and86. 1%,respectively. Compared with the traditional batch reaction process,this new micro-channel reaction process could make the nitroguanidine synthesis reaction stable and eliminate the accumulation of reaction heat and temperature fluctuations,furthermore,shorten the reaction time.