Investigating semibatch oxidation reaction of dimethyl sulfoxide with hydrogen peroxide: Thermal analysis and process optimization

Under the green development and inherently safer concept of fine chemical industry, the exothermic behavior and thermal hazard characteristics in the semi-batch process of the preparing dimethyl sulfone (MSM) by oxidizing dimethyl sulfoxide (DMSO) with hydrogen peroxide (H₂O₂) were investigated in this work. In the constant temperature mode, the thermal accumulation of the reaction process can be divided into five stages, with the first and second stages were the main exothermic stages of the reaction. Furthermore, the increase in catalyst dosage and jacket temperature, as well as the decrease in feeding rate, helps to avoid the occurrence of boiling phenomenon in the system in a certain extent, thus improving the process safety of the reaction process. Additionally, the response surface methodology was employed to identify inherently safer and intensified reaction conditions for the preparing of MSM. Prediction models for MSM yield and maximum pressure were obtained, and the results showed good accuracy. The optimal conditions for MSM synthesis were found to be a jacket temperature of 64–68 °C, a catalyst dosage of 0.001–0.0017 mol, and a feeding rate of 5–7 mL min⁻¹, providing theoretical support for the inherent safety design of the semi-batch production process of the preparing MSM.