Calorimetric study on electrolytic decomposition of hydroxylammonium nitrate (HAN) ternary mixtures

Abstract

Electrolytic decomposition of hydroxylammonium nitrate (HAN) is appealing for development of chemical micropropulsion system due to its effectiveness in thermal management. In this paper we present the decomposition characteristics and behaviour of various HAN ternary mixtures prepared according to 0 Oxygen Balance (0 OB). There are multiple stages of decomposition depending on the type of fuels added into the HAN solution. While concentrated HAN solution (73 wt%) has only single stage of decomposition, the saccharides-based HAN ternary mixtures has three stages reaction with increased energy release. The addition of nitrogen-rich compounds has sustained the electrolytic decomposition process into the second stage of reaction, which produced the highest decomposition temperature. The study also reveals a linear relationship between the electrical resistivity of HAN ternary mixture and reaction rate in the first stage of reaction, indicating the presence of Joule heating in the process. The influence of electrical resistivity of the ternary mixture became negligible in the second stage of reaction. This work concludes the importance of combined electrical and thermal energy in the first stage decomposition of HAN ternary mixtures.