Investigation of the decomposition reaction and dust explosion characteristics of crystalline dicumyl peroxide

The dicumyl peroxide (DCP) is widely used as a polymerization initiator, catalyst and vulcanizing agent in the chemical industry. A number of accidents have been caused by its thermal instability in storage or manufacturing process. Thus, its hazard characteristics have to be clearly identified. First of all, the differential scanning calorimeter (DSC) is used to measure the heat of decomposition reaction, which can contribute to understanding the reaction characteristics of DCP. The accelerating rate calorimeter (ARC) is used to measure the rates of temperature and pressure rises of decomposition reaction, and then the kinetics parameters are estimated. Furthermore, the MIKE 3 apparatus and the 20-l-Apparatus are used to measure and analyze the dust explosion characteristics of DCP at room temperature and atmospheric pressure. Finally, Semenov's thermal explosion theory is applied to investigate the critical runaway condition and the stability criterion of decomposition reaction, and to build the relationship of critical temperature, convective heat transfer coefficient, heat transfer surface area and ambient temperature. These results contribute to improving the safety in the reaction, transportation and storage processes of DCP.

Research highlights▶ The DSC thermogram of decomposition reaction of 98% crystalline DCP reveals an endothermic peak around 40 °C due to the melting point and an exothermic peak around 168 °C due to the decomposition of DCP. The released heat is equal to 744.85 J/g. The activation energy E and pre-exponential factor A are 124.58 kJ/mol and 1.19E15 min−1, respectively. ▶ The 98% crystalline DCP has a MIE between 1 and 3 mJ, which indicates that it is very sensitive to static discharge. Its maximum KSt value is 211 bar m/s at room temperature and atmospheric pressure. The explosion class is St-2, which indicates that its explosibility is strong. ▶ Two critical temperature points of Tc is obtained from the diagram of heat generation rate and theoretical critical heat removal rate vs. temperature. One is the critical extinction temperature TC,E = 442.13 K and the other is the critical ignition temperature TC,I = 373.63 K.