Determination of Kinetic Parameters of Equilibrium Peracetic Acid and Hydrogen Peroxide to Calculate Self-Accelerating Decomposition

Determination of Kinetic Parameters of Equilibrium Peracetic Acid and Hydrogen Peroxide to Calculate Self-Accelerating Decomposition Temperature Peracetic acid is a simple molecule that works as a powerful oxidant in many applications including food safety and water disinfection. The synthesis of the compound is fairly well understood due to its straightforward synthesis by mixing acetic acid and hydrogen peroxide. However, the decomposition of the compound has not been well studied. Few sources are available to provide kinetic data for the decomposition along with data that shows when the compound will undergo a self-accelerated decomposition that could lead to disastrous effects. This paper demonstrates and discusses an effortless way to determine kinetic parameters for the decomposition of peracetic acid in equilibrium with hydrogen peroxide using basic first-order kinetics. Activation energy values were found to be approximately 70-90 kJ/mol for the various formulations. The enthalpy of decomposition was determined by differential scanning calorimeter (DSC) and related to the total active oxygen of the formulation. Once these parameters were established, the self-accelerating decomposition temperature (SADT) was determined using the Semenov equation. Final SADT values were determined to be about 70°C for 225 kg drums and 60°C for 1500 kg containers. This work applies chemical kinetics to a real world system that is not well understood by its users