Thermal Hazard and Kinetic Study of Sodium Percarbonate Based on Fraser–Suzuki Deconvolution

Sodium percarbonate (SPC), as a highly efficient oxidizing agent, is widely used in the fields of cleaning and environmental protection. However, its thermal decomposition process is accompanied by significant exothermic heat release, posing risks of thermal runaway and fire hazards. In this study, the thermal decomposition data of SPC were obtained by differential scanning calorimetry (DSC). The overlapping reaction peaks were deconvoluted using the Fraser-Suzuki (FS) function, revealing two distinct reaction steps that occur consecutively. The kinetic parameters for each step were then determined separately. Kinetic analysis revealed that the activation energy for the first step is in the range of 137.22 to 151.80 kJ/mol, with the pre-exponential factor ranging from 9.62 × 10¹⁴ s^-1 to 8.66 × 10¹⁶ s^-1. For the second step, the activation energy ranges from 90.21 to 106.41 kJ/mol, and the pre-exponential factor ranges from 1.38 × 10⁹ s^-1 to 3.86 × 10¹¹ s^-1. The first subreaction was modeled by the Avrami-Erofe'ev (A4) model, while the second subreaction was modeled by the truncated Šesták-Berggren (SB) model. Based on the obtained kinetic parameters, the decomposition behavior at heating rates of 2°C/min and 20°C/min was predicted, which validated the accuracy of the kinetic parameters. Furthermore, the temperatures at which the time to the maximum reaction rate are 8 h (<i>T_D</i> ₈) and 24 h (<i>T</i> _<i>D</i>24), and the self-accelerating decomposition temperatures (SADT) were determined to be 86.6°C, 78.8°C, and 71°C, respectively. The kinetic parameters and thermal hazard evaluation results obtained in this study provide data support for determining the safe storage temperature and optimizing transportation schemes for SPC.