Research on the decomposition kinetics and thermal hazards of aniline diazonium salt

• The decomposition of aniline diazonium salt has been studied by calorimetry. • Advanced Kinetics and Technology Solutions software analyzes kinetic parameters. • The thermal risk of aniline diazonium salt is systematically evaluated. • Diazonium salt decomposition is inconsistent with the single reaction mechanism. • The choice of reactor type has a significant influence on the runaway reaction. Diazotization reaction, strong exothermic characteristics and thermal instability of diazonium salts make the production process high risk. To research thermal hazards of aniline diazonium salt, dynamic experiments are carried out by the differential scanning calorimeter (DSC) to obtain thermodynamic parameters. Moreover, the kinetic parameters are analyzed by Advanced Kinetics and Technology Solutions (AKTS) software. Finally, the GC-MS and UV spectrum are used to further study the decomposition mechanism of the aniline diazonium salt. The results indicate that aniline diazonium salt is very easy to decompose. When the heating rate is 2 K/min, the onset decomposition temperature is only 27.21 ℃ ( T onset ). The apparent activation energy of the decomposition process calculated by Friedman and Ozawa methods are respectively 98-85 kJ/mol and 110-100 kJ/mol. Under the ideal adiabatic conditions ( φ = 1), the initial temperatures of TMR ad for 24 h is only 6.2 ℃ ( T D24 ), which is predicted by the AKTS software. The decomposition process of aniline diazonium salt is inconsistent with a single reaction mechanism.