| In this paper,Accelerating rate calorimeter（ARC）,Micro-reaction calorimeter（C80）,automatic reaction calorimeter（SIMULAR）and Advanced Kinetics and Technology Solutions（AKTS）were used to conduct thermal safety assessment of Grignard reaction with strong exothermic effect by combining experimental and numerical simulation methods.The research is innovative and of significance for guiding the safety production of fine chemical production enterprises.The ARC was used to describe the self-decomposition characteristics of products from Grignard reagent preparation reaction and the coupling reaction,respectively.The results showed that the coupling product had strong thermal stability and no self-decomposition reaction occurred at 0-400℃.The reaction product prepared by Grignard reagent began to decompose at 227.22℃.C80 was used to study the self-decomposition of the reaction products prepared by Grignard reagent under different heating rates.The results showed that the stability of the reaction products prepared by Grignard reagent is poor,which has potential explosion hazards.Three kinetics methods were carried out to determine the kinetic parameters based on AKTS software and C80 data.It indicated that the relationship of the reaction process of self-decomposition and temperature can describe the self-decomposition characteristics very well.According to the thermal hazard prediction,the adiabatic temperature rise(ΔTad)of the sample at the initial temperature of 160℃,the maximum reaction rate arrival time(TMRad)and TD24was 128.3℃,>24 h and 161℃ respectively.The grade of reaction risk according to the risk matrix was grade I,belonging to an acceptable risk,and the reaction risk was small after cooling failure.The results showed that the molar heat of（ΔrHm）was 361.29 kJ/mol,ΔTad was above 200℃when the reaction occured out of control,and the maximum temperature（MTSR）that the reaction can reach was 87.45℃.When the maximum temperature of reaction equipment taken as the maximum temperature（MTT）caused by technical reasons was 210℃,the reaction thermal runaway grade was level 2 by the out-of-control scenario analysis method,indicating that the whole reaction process was relatively safe.When the boiling point of the solvent was taken as MTT with 65.4℃,the thermal runaway grade of the reaction was 3.Based on the analysis of the exothermic characteristics of Grignard’s reagent preparation reaction,it is concluded that the mass of parabromotoluene mixture added in one time in the initiation stage should not exceed 10%of the total mass,otherwise thermal accumulation would occur in the initiation stage,resulting in dangerous situation. |
