(60c) Isothermal Decomposition of Hydroxylamine and Hydroxylamine Nitrate in Aqueous Solutions in the Temperature Range 353-400 K

Hydroxylamine (HA) and hydroxylamine nitrate (HAN) have been involved independently in several tragic accidents [1, 2] that incurred numerous fatalities and injuries. Following these incidents, MKOPSC [3, 4] and other research institutes have conducted a series of research on HA and HAN, but the mechanism of their unstable behavior still have not been completely understood. In those research, the runaway behaviors of HA and HAN have been studied by adiabatic calorimetry tests and other means. The temperature, pressure and heat generation profiles of the system have been obtained under selected runaway conditions. Additionally, the kinetics of their thermal decompositions has been elucidated by theoretical model combining with experimental results. The potential reaction pathways have been discussed by analyzing the end products of the decomposition.

In the present work, their isothermal decomposition behaviors have been studied by calorimetry tests and accompanied with HPLC, Ion chromatography and UV analyses in the temperature range 353-400 K. Condition dependent autocatalytic decompositions have been demonstrated for HA and HAN and an intermediate formation have been observed that is most likely responsible for their autocatalytic behavior. These findings corroborate previously reported computational chemistry results