对氟苯胺重氮化反应安全工艺OA

The diazotization of p-fluoroaniline is characterized as a hazardous chemical process,and its safe transformation necessitates further exploration.Utilizing microchannel continuous-flow safety technology,the effects of material molar ratio,operating temperature and residence time on the yield and conversion rate were investigated.Additionally,numerical calculation method was employed to study the heat release patterns and influencing factors of the diazotization reaction in a microchannel reactor under optimal conditions.The results show that the microchannel continuous-flow reaction attains optimal performance when the molar ratio of sodium nitrite to p-fluoroaniline is set at 1.10∶1,the reaction temperature is maintained at 15℃,and the residence time is 102 s.Under these optimal conditions,the temperature of the microchannel continuous reaction initially spikes to a maximum of 27.8℃ and then returns to the initial temperature of 15 ℃ after traveling 5 000 mm.As the flow rate increases,the maximum temperature rise remains constant,but the temperature peak shifts later and the temperature distribution becomes more extended,enhancing process safety.In an adiabatic environment within the reaction zone,the maximum temperature rises to 36.7 ℃ and eventually stabilizes at 34.1℃,keeping the risk of thermal runaway within manageable limits.This underscores that the microchannel continuous-flow process for p-fluoroaniline diazotization significantly bolsters reaction safety and offers insights for the safe industrial production of p-fluorophenylhydrazine hydrochloride.