Thermal decomposition of alkyl pyridine N-oxides: Thermal runway study using the Automatic Pressure Tracking Adiabatic Calorimeter (APTAC)

Thermal runaway is one of the major causes behind accidents in process industries leading to several fatalities, injuries and property damage. It is usually due to uncontrolled increase in temperature leading to high pressure in a chemical reaction such as polymerization, hydrolysis, oxidation, sulphonation, decomposition etc. In this particular work, decomposition of the oxidation product of 3-Picoline N-oxide is studied in an Automatic Pressure Tracking Adiabatic Calorimeter (APTAC) to determine the onset temperature of decomposition, the influence of catalyst concentration and temperature on the decomposition using Heat Wait Search (HWS) and isothermal mode. Results of HWS showed that decomposition of 3-picoline N-oxide with catalyst could lead to runaway. This can lead to sudden increase of temperature and pressure in the reactors. In isothermal experiments, it was observed that there can be an optimized amount of catalyst which can increase the operational range of temperature and pressure for safer handling of these reactions.