Figure 1:
Adiabatic reaction progress (DSC, normalized signals) of an exothermic reaction as a function of time for several starting temperatures To = 30, 40, 50 and 60°C (marked on curves) with Tad = 220 °C.
 

Figure 2:
Calculations of the adiabatic self-heating reaction determined for several starting temperatures To = 30, 40, 50 and 60°C (marked on curves) with Tad = 220°C.



Figure 3:
AKTS-Thermokinetics software input.

Let us consider the reaction progress of an exothermic process. Using the reaction heat (Hr) and the heat capacity (cp), one can calculate the reaction progress due to self-heating for any value of Tad (with Tad = Hr/cp). The adiabatic induction time is defined as the time which is needed for the self-heating from the start temperature to the time of maximum rate. Depending on the Tad considered, the choice of the starting temperatures strongly influences the adiabatic induction time and, therefore, the boundary conditions valid for achieving necessary safety e.g. storage of self-reactive substances.