5 The effect of contaminants on ammonium nitrate decomposition 29 5.1 Acids, bases and water 29 5.2 Halides 30 5.3 Metal ions 33 5.4 Combustible material 34 6 Discussion and concluding remarks 38 References 40. Starting with an existing nitramine/TATB ReaxFF parameterization, we optimized it to reproduce electronic structure calculations for dissociation barriers, heats of formation, and crystal structure properties of ammonium nitrate phases. Find more information on this substance at: http://www.epa.gov/oem/docs/chem/AN_advisory.pdf/. If you are the author of this article you still need to obtain permission to reproduce When comparing mass burning rates, ammonium perchlorate compares favorably to solid fuels such as hydroxyl-terminated polybutadiene. do not need to formally request permission to reproduce material contained in this John Wiley & Sons, Inc. New York, NY 2007. Reduction of NOx emission and enhancement of ammonium nitrate conversion, demonstrate superiority of AMFR to previous configurations. Get the latest public health information from CDC: https://www.coronavirus.govGet the latest research information from NIH: https://www.nih.gov/coronavirus, PDF documents can be viewed with the free Adobe® Reader. Laboratoire d'Electrochimie, Chimie des Interfaces et Modélisation pour l'Energie, CNRS UMR-7575, Ecole Nationale Supérieure de Chimie de Paris Chimie Paris-Tech, 11 rue P. et M. Curie, 75231 Paris Cedex 05, France Instructions for using Copyright Clearance Center page for details. 1249. Several amphoteric and basic oxides and salts as well as some neutral salts were added in varying amounts to control pH. Decomposition of sodium hypochlorite takes place within a few seconds with the following salts: ammonium acetate, ammonium carbonate, ammonium nitrate, ammonium oxalate, and ammonium phosphate. The UN classification of AN as an oxidizer, instead of as an explosive, should not be interpreted literally, since AN has been associated with numerous detonation disasters. The explosive nature of ammonium nitrate is due to its decomposition into gaseous products (nitrogen, H 2 O vapor, and oxygen) and also due to the exothermic nature of the reaction. Bimetallic catalysts M-M'/Al2O3-Si (M, M' = Fe, Cu, Zn, Pt) have been evaluated too. The rate then dropped to about 2.5% per hour with a slight increase as the heating period progressed. In order to obtain a better understanding of the combustion characteristics of ammonium nitrate (AN) and carbon (C) mixtures (AN/C), burning tests and differential scanning calorimetry (DSC) were performed. The results of analyses of the gaseous compounds evolved at thermal treatment of neat AN indicated some differences in the decomposition of AN in air or in N2. If you are the author of this article you do not need to formally request permission [16] Find another reaction. An accurate DFT benchmark study was then conducted to determine the most suitable exchange–correlation functional to accurately describe the reaction profile both in terms of structures and thermochemistry. 5 Howick Place | London | SW1P 1WG. The resulting heat and pressure from the decomposition of ammonium nitrate may build up if the reaction takes place in a confined space and the heat and gases created are not able to dissipate. In contrast, AN mixed with graphite and AN mixed with fullerene had a relatively small exothermic peak, the same as that observed for pure AN. The decomposition rate of pure NH4NO3 climbed during the first 2 hours until it was equivalent to a weight loss per hour of about 5.5% of the original sample. Flame imaging revealed large melt layers and boiling type behavior for ammonium nitrate and phase-stabilized ammonium nitrate as well as droplet ejection from the melt layer. Heat characteristic examinations found a similar trend. contained in this article in third party publications Fetching data from CrossRef. The effect of additives like oxides, cations, inorganic acids, organic compounds, phase-stablized CuO, etc., is discussed. Hazardous scenarios with ammonium nitrate can involve simple thermal decomposition initiated by external fire or other heating, self-sustained decomposition also known as "cigar burning," and detonation. Thus, AN fertilizer explosions in storage are preventable accidents, because technology to preclude uncontrollable fires also has been available for a century. At the thermal treatment of AN’s blends with CaCO3, MgCO3, limestone and dolomite samples the decomposition of AN proceeds through a completely different mechanism — depending on the origin and the content of additives, partially or completely, through the formation of Mg(NO3)2 and Ca(NO3)2. This mechanism was coupled to a gas-phase mechanism, making it possible to quantify the contributions of condensed-phase and gas-phase reaction pathways to AN thermal decomposition at different heating rates. It was examined that mixtures of mineral oil and fertilizers containing over 20% of mineral meal detonated during the tests. Reproduced material should be attributed as follows: If the material has been adapted instead of reproduced from the original RSC publication These have, thus far, not produced guidance useful for promoting of safety from fire‐related causes. The results of 200-mL closed vessel test showed that the powdered AN and the phase stabilized AN (PSAN) mixed with AC showed a fast reaction and a high pressure due to the large amount of gas release and the maximum pressure, and the maximum rate of pressure rise showed the maximum values at a higher concentration than the stoichiometric composition. Ammonium nitrate (AN) is one of the main nitrogen fertilizers used in fertilization programs. The burning rate of AN/AC mixed with CuO as a combustion catalyst deteriorated faster than an additive‐free one. of the whole article in a thesis or dissertation. Furthermore, the high barrier to overcome in the rate determining step well explained the fact that the reaction is not usually spontaneous and requires a significant external stimulus for its onset. National Fire Protection Association; Fire Protection Guide to Hazardous Materials. The thermal deNOx pathway and hydroxylamine decomposition impact significantly NH3 consumption in the monopropellant flame zone. Ammonium nitrate melts at 337 deg F (170 deg C) and begins to undergo decomposition when molten. to access the full features of the site or access our. The study revealed that T50 (temperature at 50% conversion) increases strongly with the heating rate, favoring highly activated reactions. 71. Decomposes @ 210 deg C, with evolution of nitrous oxide. DOI: 10.1002/jctb.503310144. The decomposition mechanism of ammonium nitrate in the gas phase was investigated and fully characterized by means of CBS-QB3 calculations. The decomposition reaction can be summarized as Ammonium nitrate has been used for centuries in warfare, but is also a mainstay of commercial nitrogenous fertilizers. The decomposition of ammonium nitrate in the presence of ammonium chloride (0.1%) becomes violent around 175 deg C. The gases liberated contain chlorine. EUR 45.00 We then simulated thermal decomposition during heating to 2500 K. Thermal decomposition pathways agreed with experimental findings. However, AN mixed with carbon that is not oxidized by HNO3, such as graphite, did not burn under 7 MPa. 3099067 Indeed, this level of theory provided the lowest deviations with respect to CBS-QB3 reference values, outperforming functionals especially developed for reaction kinetics. This evaluation supports the use of the M06-2X functional as the best option for the study of ammonium nitrate decomposition and related reactions. The values of maximum of transformation rate were compared with energies of chemical bonds between ions. Use the link below to share a full-text version of this article with your friends and colleagues. This is consistent with many field observations of detonations at low ambient temperatures. The full text of this article hosted at iucr.org is unavailable due to technical difficulties. Ammonium nitrate NH4NO3 (AN) is a proposed candidate for energetic ionic liquids and solid propellants. Information about reproducing material from RSC articles with different licences We use cookies to improve your website experience. Five reaction channels were identified, leading to the formation of products (N2, H2O, O2, OH, HNO, NO3) found in the experimental works. As the temperature rises, the rate of decomposition increases. Both neat AN and AN containing various contaminants are examined, however quantitative kinetics results are not encompassed. Experiments were carried out under dynamic heating condition up to 900°C (10°C min−1) in a stream of dry air or N2 by using Setaram Labsys 2000 equipment coupled to Fourier transform infrared spectrometer (FTIR). The resulting nitrogen oxides will support combustion, even in the absence of other oxygen. The alkali and ammonium bromides and iodides proved to be effective inhibitors in concentrations as low as 0.5%. Institut National de l'Environnement Industriel et des Risques (INERIS), Parc Technologique Alata, BP2, 60550 Verneuil-en-Halatte, France, c