Skip to Main content Skip to Navigation
Conference papers

Theoretical approach to better understand industrial risks linked to the incompatibilities of ammonium nitrate

Abstract : The ammonium nitrate (AN) is a widely used product in chemical industry present in fertilizers and in explosive mixtures. Although pure ammonium nitrate is generally used safely (as chemically relatively stable at normal temperature and pressure), significant accidents occurred causing a number of deaths and injuries as dramatically demonstrated by the Toulouse disaster in September 2001. Indeed, when ammonium nitrate is mixed with combustible materials, metals, acids, chlorides, sulfates and sodium dichloroisocyanurate, its explosive properties can be considerably increased. Despite its large use and its latent risk of accidental detonation under specific conditions, the decomposition mechanism of AN and its evolution in presence of contaminants are not yet unambiguously defined as many hypotheses remain. Complementary to experimental methods which are commonly used to describe incompatibilities between substances (in terms of energy release and temperature of decomposition), molecular modeling was used in this work to better understand the reactions involved in this process. In particular, the theoretical study of the ammonium nitrate’s incompatibilities was performed with the aim to understand the mechanism through which the explosive reaction takes place, to identify which molecules can be really generated from this process and to estimate the energy involved. To do this, a study of all the available mechanisms of AN decomposition, in terms of structural and energetic characterization of reaction intermediates and products, was conducted at DFT (Density Functional Theory) level of theory. In a first step, a preliminary DFT benchmark on the ammonium nitrate’s decomposition reaction was carried out to determine the most efficient combination of DFT method and basis set to describe accurately ammonium nitrate and its decomposition pathways. Then, this method was applied to identify reaction mechanisms of major ammonium nitrate’s incompatibilities. In particular, the reaction between ammonium nitrate and the sodium salt of dichloroisocyanuric acid was investigated and fully characterized.
Document type :
Conference papers
Complete list of metadatas

https://hal-ineris.archives-ouvertes.fr/ineris-01855596
Contributor : Gestionnaire Civs <>
Submitted on : Wednesday, August 8, 2018 - 11:44:40 AM
Last modification on : Tuesday, September 22, 2020 - 3:38:36 AM

Identifiers

  • HAL Id : ineris-01855596, version 1

Collections

Citation

Stefania Cagnina, Patricia Rotureau, Guillaume Fayet, Carlo Adamo. Theoretical approach to better understand industrial risks linked to the incompatibilities of ammonium nitrate. 10. Congress of the World Association of Theoretical and Computational Chemists (WATOC 2014), Oct 2014, Santiago, Chile. ⟨ineris-01855596⟩

Share

Metrics

Record views

66