The use of adiabatic calorimetry for the process analysis and safety evaluation in free radical polymerization

Adiabatic calorimetry is a technique that has been introduced as an importa nt approach to hazard evaluation of exothermically reactive systems. In thi s paper the free radical polymerization of methyl methacrylate (MMA) has be en studied. One of the most important aspects of MMA polymerization is its exothermicity and autoaccelerating behaviour, these characteristics can gen erate the occurrence of a runaway reaction. In a runaway situation the reacting system is close to adiabatic behaviour because it is unable to eliminate the heat that is being generated. An even worse situation can be reproduced in the laboratory with the Phi-Tec pseud o-adiabatic calorimeter. Process design parameters that are usually calcula ted from thermodynamic data or using semiempirical rules, such as adiabatic temperature rise or maximum attainable pressure, can be directly determine d. The existence of the ceiling temperature has been experimentally demonstrat ed.