Identification of the Decomposition Products in an Industrial Nitration Process under Thermal Runaway Conditions

Directive 96/82/EC on the control of major-accident hazards involving dangerous substances, so-called Seveso II Directive, requires inventorying of dangerous substances which are believed might be generated during loss of control of an industrial chemical process. In the present work a nitration process that has underlined a potential risk of thermal runaway has been studied. A kinetic model has been developed and validated using the calorimetric data from a Mettler RC1 and a differential scanning calorimeter, along with the commercial software BatchCAD. The model has been later used to simulate the behaviour of an industrial reactor under abnormal conditions and to evaluate their consequences. Finally, the conditions that lead to thermal runaway scenarios have been reproduced to identify the decomposition products, as Seveso II Directive requires, using thermogravimetry and adiabatic calorimetry coupled with FTIR gas analyser.