Decomposition equations of ammonium perchlorate

The data existing for the thermal decomposition equations of ammonium perchlorate (AP) have been reviewed after reducing them to a common basis (100 moles of AP). They have been evaluated from two points of view: (a) stoicheiometric balance of the elements present, and (b) establishment of thermodynamic equilibrium of the final gaseous products. From a knowledge of the distribution of the nitrogen between N2, N2O and NO, and of the chlorine between Cl2 and HCl (the latter derived from the equilibrium constant for the Deacon process), the corresponding equilibrium temperatures (Teq) and the flame temperatures (Tt) have been calculated. These temperatures agree in a number of cases with the measured heating temperatures and temperatures of the gas flame. Extrapolation of the equilibrium gas compositions calculated for different pressures indicates that the gas composition at equilibrium lies between two asymptotic extremes which are: For zero pressure or for relatively low Teq and for high pressures or for relatively high Teq, Below 300° some ClO2 forms, and N2O instead of NO. NO when, formed reacts giving nitrosy1 compounds. At all temperatures there may occur a ‘freezing’ of non‐equilibrium compositions.