As a self-reactive substance, benzaldehyde oxime (BO) is prone to a highly exothermic runaway reaction and thermal hazard analysis and the reaction kinetics calculation of BO have great significance. In this work, the decomposition products of BO in nitrogen atmosphere were identified by GC–MS and HPLC techniques. The impact of the decomposition products on the decomposition behaviors of BO were analyzed by comparison of the ARC test results of pure BO and mixture of BO and decomposition products. It was found that N-benzylidene benzylamine was the intermediate decomposition product and benzoic acid , benzamide, N-benzyl benzamide, and 2,4,5-triphenylimidazole were the final products of BO. A two-step continuous autocatalytic reaction model was established to depict the decomposition process of BO. The kinetic parameters of the model were calculated by applying the nonlinear optimization method. Finally, thermal behaviors under different process temperature were predicted based on the kinetic model , and the time to maximum rate (TMR ad ) was predicted as 112.04 °C under 24 h, and 122.19 °C of 8 h, which offer crucial safety information to optimize the safety conditions of BO during usage, storage and transportation, which minimizes the industrial disasters.
Wei Jiang,Lei Ni,Juncheng Jiang,Qiang Chen,Zhiquan Chen,Shuliang Ye
In this study, various calorimetric and analytical techniques were used to evaluate the thermodynamics of the preparation of adipic acid through the oxidation with hydrogen peroxide. The reaction exotherm was combined with the reaction mechanism. Differential scanning calorimetry revealed that the hydrogen peroxide was relatively stable when Na 2 WO 4 .2H 2 O and H 2 SO 4 were used as cocatalysts. Reaction calorimetry, in situ Fourier transform infrared spectroscopy and gas chromatography/mass spectrometry (GC/MS) results indicated a possible macroscopic reaction pathway at 73 and 90°C stage. Furthermore, the results obtained through adiabatic calorimeter (Phi-TEC II) and GC/MS indicated the possibility of catastrophic accidents if control of the target reaction was lost. The criticality classes of this reaction were of Grade 5. The results of this study can be further used to improve the inherent safety of its operating measures, as a result, this reaction process can be scaled up.