Behavior of Autocatalytic Reactions

Figu re 12.1 Comparison of autocatalytic (a) an nth-order (ri) reactions in an isothermal DSC experiment performed at 200°C. Both reactions present a maximum heat release rate of lOOWkg 1 at 200°C. The induction time of the autocatalytic reaction leads to a delay in the reaction course. 

This is due to the fact that under isothermal conditions, the nth-order reaction presents its maximum heat release rate at the beginning of the exposure to initial temperature, whereas the autocatalytic reaction presents no heat release rate at this time. Thus, temperature increase is delayed and only detected later after an induction period, as the reaction rate becomes sufficiently fast. Hence acceleration, due to both product concentration and temperature increase, becomes very sharp. 

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The first section of this chapter is an introduction of basic definitions, describing the behavior of autocatalytic reactions, their reaction mechanism, and a phenomenological study. The second section is devoted to their characterization and the last section gives some hints on mastering this category of reaction in the industrial environment. 

Different factors may strongly affect the behavior of autocatalytic reactions, especially if we consider the adiabatic temperature course that is used to predict the TMRad. Such effects are shown by numerical simulations using the Berlin model. 

To illustrate the behavior of autocatalytic reactions, let s arbitrarily assumed the following values ... 

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