Theoretical and Experimental Study of the Reaction between Ammonium Nitrate and Sodium Salts

Abstract

Hazards posed by chemical incompatibility, especially in a large-scale industrial environment, warrant a deeper understanding of the mechanisms of the reactions involved in these phenomena. In this study, reactions between ammonium nitrate and two sodium salts, namely, sodium nitrate and sodium nitrite, have been studied by ab initio calculations (with density functional theory, DFT) and experimental calorimetric methods (with differential scanning calorimetry, DSC, and heat flux calorimetry, HFC). The agreement between theoretical and experimental results allows an understanding of the thermal decomposition behaviors of the two sodium salts when exposed to ammonium nitrate. Moreover, this study highlighted the critical role of the water that appears to promote the incompatibility between ammonium nitrate and sodium nitrite.

Thermal decomposition of ammonium nitrate

“…In a 2014 study, Cagnina et al proposed five different decomposition pathways for AN, each one involving a dozen or so steps. Later, Cagnina and coworkers examined reactions between AN and some sodium salts using DFT, accompanied by some thermal analysis experiments. Their studies showed that chemical incompatibility between chemicals, for example, AN with NaNO 2 and NaNO 3 , could be successfully predicted.…”

“…The conclusion here is that these types of advanced studies can be expected to become more important in the future, but the endeavors thus far have generally not been helpful toward identifying the most‐valid reaction schemes based on a tractable number of reactions. An exception is the extensive study of Izato et al, where the authors did use the results of their calculations to reflect on the likelihood of importance of various decomposition reactions proposed by earlier researchers.…”

In situ controlled rapid growth of novel high activity TiB2/(TiB2–TiN) hierarchical/heterostructured nanocomposites

“…At the same time, the high temperature could promote NH 4 NO 3 splitting into active N*, NO x and H 2 O ( Eq. 10 ) [ 24 – 25 ]. Under the special reaction coupling self-propagating high-temperature environment, N* and the rest of Ti* could be deposited on the surface of the TiB 2 crystals, and finally, the novel TiB 2 /(TiB 2 –TiN) hierarchical/heterostructured nanocomposites are the product ( Eq.…”

Kinetic analysis of the thermal decomposition of liquid ammonium nitrate based on thermal analysis and detailed reaction simulations

“…However, the poor combustion properties of AN, including low ignitability and sluggish burning rates under low pressure conditions, have prevented the application of AN-based propellants to date. As a result, there have been many studies aimed at improving the combustion characteristics of AN in combination with various catalysts or fuels [5][6][7][8][9][10][11][12]. Despite this prior work, the combustion properties of AN-based propellants still require improvement.…”