Research On Thermal Stability Of Hydrogen Peroxide And Benzoyl Peroxide With Impurities

Oxidants and organic peroxides have been widely used in various fields of industrial production.However,such materials have strong oxidizing properties and are susceptible to combustion and explosion when heated or mixed with impurities.Therefore,it is important to study the thermal hazard of oxidants and organic peroxides.In this paper,30%hydrogen peroxide（H₂O₂）and 75%benzoyl peroxide（BPO）were chosed to study the thermal hazard of impuritiesunder different types and different contents,and to obtain exothermic characteristics,thermal kinetics,thermal explosion critical conditions,storage and transportation indicators,etc.First,different type of DSC crucible were selected to study effect of crucible material;then scanning scanning calorimeter（DSC）and adiabatic calorimeter（ARC）were used to impurity screening and obtain exothermic parameters,such as onset temperature,heat release,gas productionand adiabatic temperature rise;based on DSC and ARC data,activation energy,pre-exponential factor and reaction mechanism function by model-free method and nonlinear model-based method;finally,based on the kinetic model,predicts storage,transportation,and thermal explosion parameters were obtained by thermal safety software（TSS）.As for H₂O₂,steel crucible can catalyze the decomposition of H₂O₂.Small amount of metal ion impurities（FeCl₃,FeCl₂ and CuCl₂ solutions）and alkaline solutions（NaOH,Na₂CO₃,NaHCO₃,NH₄HCO₃）have significant effect on the decomposition of H₂O₂,because of catalyze of impurities;In the kinetic calculation by Friedman method,the activation energy ofH₂O₂,H₂O₂ with NH₄HCO₃ and H₂O₂ with CuCl₂were 40-48kJ/mol、55-63kJ/mol and 30-35kJ/mol,respectively,which can be considered as single stage reaction.By the nonlinear model fitting method,H₂O₂,H₂O₂ with NH₄HCO₃ were in accordance with the single-step n-stage reaction model.In the self-accelerating decomposition temperature（SADT）prediction,H₂O₂,H₂O₂ with NH₄HCO₃were 18℃and-10℃;TMR_ad and TCL were decrease when impurity added.As for BPO,material has littlr effect on the decomposition of BPO.CuCl₂ and NaOH have an effect on the decomposition of BPO,impurities react with BPO.the activation energy of BPO,BPO with NaOH varied greatly with the conversion rate.The BPO and the BPO with NaOH conform to the two-step continuous reaction model A→B→C,where A→B is an autocatalytic reaction,B→C is an n-order reaction.In the prediction of heat hazard parameters,the larger the package,the lowerSADT,the lower the impurity content than the impurity-free;TMRad and TCL,the impurity value were lower than the pure product.Therefore,it is necessary to prevent impurities from being mixed into the system during storage and transportation..This paper provides basic data and analytical method techniques for studying the thermal stability of substances containing impurities,and has certain guiding significance for the safe use of hydrogen peroxide and BPO.