Reaction hazard and mechanism study of H₂O₂ oxidation of 2-butanol to methyl ethyl ketone using DSC, Phi-TEC II and GC-MS

Methyl ethyl ketone (MEK) oxidation via H₂O₂ with tungsten-based polyoxometalate catalysts has gained much attention with an ever-growing body of knowledge focusing on the development of environmentally benign processes in chemical industry. In this study, two calorimetry techniques, differential scanning calorimetry (DSC) and Phi-TEC II adiabatic calorimetry, were employed to analyze the thermal hazards associated with the 2-butanol oxidation reaction system. Hydrogen peroxide was the oxidant and a tungsten-based polyoxometalate as the catalyst. Gas chromatography-mass spectrometry was used for identification of the organic products. Important thermal kinetic data were obtained including “onset” temperature, heat of reaction, adiabatic temperature rise and self-heat rate. From DSC results, three exothermic peaks were detected with a total heat generation of approximately 1.26 kJ/g sufficiently to induce a thermal runaway. Possible reaction pathway for three stages were proposed based on both DSC and GC-MS results. One exotherm was detected by Phi-TEC II calorimeter and the pressure versus temperature profile together with the DSC and GC-MS data demonstrate the complexity of 2-butanol reaction system under both thermal screening and adiabatic conditions.