Thermal Decomposition Of Ammonium Nitrate Research Articles

Kinetics and mechanism of thermal decomposition of ammonium nitrate and sulfate mixtures

Fundamental kinetic aspects of the decomposition of mixtures and double salts of ammonium nitrate and ammonium sulfate were studied. The effect of water and sulfuric acid additives on the thermal decomposition rate of ammonium nitrate and sulfate mixtures was examined. The constant of proton exchange between nitric acid and the sulfate anion in molten ammonium nitrate was estimated.

Humphry Davy

Humphry Davy

THERMAL DECOMPOSITION BEHAVIORS OF AMMONIUM NITRATE AND CARBON MIXTURES

The influence of the physical form of carbon on the thermal decomposition of ammonium nitrate (AN) and carbon mixtures was investigated by Raman spectroscopy, differential scanning calorimetry (DSC), and thermogravimetry-infrared (TG-IR) spectroscopy. The DSC results revealed that AN mixed with activated carbon and AN mixed with carbon nanotubes underwent a violent reaction after the AN melted. 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 TG-IR spectroscopy results revealed that more carbon dioxide was generated by AN mixed with activated carbon and AN mixed with carbon nanotubes than by the other two mixtures. Furthermore, DSC was performed for AN mixed with carbon blacks having different particle diameters. It is concluded that AN mixed with low-crystallinity carbon reacts violently after melting, whereas AN mixed with high-crystallinity carbon exhibits the same thermal decomposition behavior as pure AN. The thermal decomposition behaviors of mixtures of AN and activated carbon were investigated by performing thermochemical calculations, and the reaction mechanism is discussed.

Thermal Decomposition of Gaseous Ammonium Nitrate at Low Pressure: Kinetic Modeling of Product Formation and Heterogeneous Decomposition of Nitric Acid

The thermal decomposition of ammonium nitrate, NH(4)NO(3) (AN), in the gas phase has been studied at 423-56 K by pyrolysis/mass spectrometry under low-pressure conditions using a Saalfeld reactor coated with boric acid. The sublimation of NH(4)NO(3) at 423 K was proposed to produce equal amounts of NH(3) and HNO(3), followed by the decomposition reaction of HNO(3), HNO(3) + M --> OH + NO(2) + M (where M = third-body and reactor surface). The absolute yields of N(2), N(2)O, H(2)O, and NH(3), which can be unambiguously measured and quantitatively calibrated under a constant pressure at 5-6.2 torr He are kinetically modeled using the detailed [H,N,O]-mechanism established earlier for the simulation of NH(3)-NO(2) (Park, J.; Lin, M. C. Technologies and Combustion for a Clean Environment. Proc. 4th Int. Conf. 1997, 34-1, 1-5) and ADN decomposition reactions (Park, J.; Chakraborty, D.; Lin, M. C. Proc. Combust. Inst. 1998, 27, 2351-2357). Since the homogeneous decomposition reaction of HNO(3) itself was found to be too slow to account for the consumption of reactants and the formation of products, we also introduced the heterogeneous decomposition of HNO(3) in our kinetic modeling. The heterogeneous decomposition rate of HNO(3), HNO(3) + (B(2)O(3)/SiO(2)) --> OH + NO(2) + (B(2)O(3)/SiO(2)), was determined by varying its rate to match the modeled result to the measured concentrations of NH(3) and H(2)O; the rate could be represented by k(2b) = 7.91 x 10(7) exp(-12 600/T) s(-1), which appears to be consistent with those reported by Johnston and co-workers (Johnston, H. S.; Foering, L.; Tao, Y.-S.; Messerly, G. H. J. Am. Chem. Soc. 1951, 73, 2319-2321) for HNO(3) decomposition on glass reactors at higher temperatures. Notably, the concentration profiles of all species measured could be satisfactorily predicted by the existing [H,N,O]-mechanism with the heterogeneous initiation process.

Shock-wave sensitivity and self-propagating explosive processes in binary mixtures on the basis of ammonium nitrate with exo- and endothermic transformations of the components

Experimental data on the shock-wave sensitivity and the intensity of thermal decomposition of ammonium nitrate of different brands and substances decomposing with endothermic effect and their mixtures with ammonium nitrate at various different impact amplitudes are presented. The ability of the indicated substance to sustain self-propagating explosive processes in steel tubes with diameters less than the critical diameter of detonation is examined. A correlation between the data on the decomposition intensity of the substances behind a shock wave, the kinetic characteristics of their thermal transformation at comparatively low temperatures, and their ability to sustain self-propagating explosive processes was established.

Pressure dependence of thermal decomposition of ammonium nitrate oxidizer

There is an increasing interest in research and development of ecofriendly solid propellant systems which can replace the existing ones in applications particularly where the rockets have to be fired in close proximity ofthe personnel and smokeless HCI-free burning is desired. Ammonium nitrate (AN) is receiving wide attention as a possible substitute for ammonium perchlorate oxidizer in view of the hazardous nature of other candidates like nitramines and non-availability of substances like ammonium dinitramide in requisite quantities besides the cost effectiveness. The phase transitions and initial endothermic decomposition of ammonium nitrate, however, pose problems in its application in composite solid rocket propellants. The influence of pressure on phase transitions, melting and thermal decomposition characteristics of AN is required to be systematically studied in order to have an insight in the combustion mechanism of AN containing propellants. Pressure differential scanning calorimetric (PDSC) studies have consequently been conducted on pure AN under ambient conditions and upto a maximum inert pressure of 68.03 atm. The shifts in the phase transition peaks, melting and decomposition temperatures with pressure have been studied. It has been observed that thermal decomposition of AN remains an endothermic process upto a prepare of 20.41 atm and thereafter becomes exothermic in nature. Phase transitions, melting and decomposition processes are found to be pressure sensitive and the associated peaks register a positive temperature shift bearing a relationship with crystal structure in two distinct pressure segments corresponding to endo- and exothermic decomposition.

Thermal decomposition features of ammonium nitrate and its boron mixture under high pressures

AbstractThe kinetics of ammonium nitrate thermal decomposition was studied by the differential thermal analysis in the pressure range from atmospheric to 1.0 GPa. The decomposition under pressure was shown to obey the zero‐order equation with a constant proportional to the initial HNO3 concentration in the sample. The structural transitions in ammonium nitrate were found to affect its exothermic interaction with boron. The mechanism of this phenomenon was interpreted. The experimental data allowed to establish volume changes on melting ammonium nitrate, equal to 0.072 cm3/g.

Thermal decomposition of ammonium nitrate dispersed in a multicomponent nitrate system

To obtain the kinetic curves of thermal decomposition of ammonium nitrate occurring together with decomposition of metal nitrates contained in a mixture, the ammonia contents evolved from samples heated under thermoanalytical conditions were determined by the Kjeldahl method.

Effect of ammonia on the thermal decomposition of ammonium nitrate

AbstractThe effect of the partial pressure of gaseous ammonia on differential thermal analysis and thermogravimetric curves of ammonium nitrate has been determined. Observed variations of the thermal effect and decomposition rate constitute a basis for considering the factors which determine the decomposition and equilibrium of exo‐ and endothermic processes.

The effect of nitric oxide and nitrogen dioxide on the thermal decomposition of ammonium nitrate

AbstractThe effect of the partial pressures of nitric oxide and nitrogen dioxide in the gaseous phase (0–0.1 MPa) on the profile of differential thermal analysis and thermogravimetric curves for ammonium nitrate, on its rate of decomposition (from 388 to 548 K), and on nitric acid concentration in the condensed phase have been investigated. Both compounds were found to increase the isothermal decomposition rate and also to lower the temperature of initiation. The results of these studies have led to the conclusion that as the factors causing an increase in the concentration of both compounds in ammonium nitrate increase, the possibility of ignition or explosion also increases.

The effect of nitric oxide and nitrogen dioxide on the thermal decomposition of ammonium nitrate

The effect of nitric oxide and nitrogen dioxide on the thermal decomposition of ammonium nitrate

Effect of ammonia on the thermal decomposition of ammonium nitrate

Effect of ammonia on the thermal decomposition of ammonium nitrate

A new gas volumetric determination of the nitrate ion

The gas volumetric determination is based on the thermal decomposition of ammonium nitrate which is carried out in a fused ammonium hydrogensulphate—ammonium sulphate mixture placed in a two-step reactor. The method is easily applicable for the analysis of solid inorganic nitrates, and can also be used for solutions.

A study of the thermal decomposition of ammonium nitrate using a gas chromatographic technique

AbstractThe thermal decomposition of ammonium nitrate and associated mixtures in the range 170 to 200 °C has been studied by measuring the rate of evolution of nitrous oxide using a flow system in conjunction with a gas chromatograph enabling measurements to be made at temperatures of practical importance not covered in most previous investigations. The rate constant calculated from the data for pure ammonium nitrate was compared with the values of other workers.The effects of water and of monoammonium phosphate on the decomposition rate were studied. The effect of several metal ions on the decomposition rate was also studied, but no clear pattern emerged from the results.

Inhibition of the thermal decomposition of ammonium nitrate

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTInhibition of the thermal decomposition of ammonium nitrateGeorge H. Madany and George. BurnetCite this: J. Agric. Food Chem. 1968, 16, 1, 136–141Publication Date (Print):January 1, 1968Publication History Published online1 May 2002Published inissue 1 January 1968https://doi.org/10.1021/jf60155a024RIGHTS & PERMISSIONSArticle Views149Altmetric-Citations7LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (573 KB) Get e-Alerts Get e-Alerts

The thermal decomposition of ammonium nitrate in fused salt solution and in the presence of added salts

AbstractThe thermal decomposition of ammonium nitrate in a fused equimolar mixture of sodium and potassium nitrates has been studied. It is shown that the reaction is first order with respect to ammonium ions. the rate of decomposition is increased by cations of a highly polarising nature, whereas anions, such as sulphates, phosphates and fluorides, which act as bases in the system, decrease the rate of decomposition. the observations are in accord with an ionic mechanism for the decomposition of ammonium nitrate, involving the reaction of ammonia with the nitronium ion.

Order of Reaction in the Thermal Decomposition of Ammonium Nitrate

Order of Reaction in the Thermal Decomposition of Ammonium Nitrate

Mechanism for the Chloride-Catalyzed Thermal Decomposition of Ammonium Nitrate

A kinetic study of the thermal decomposition of NH4NO3 in the presence of NaCl has been carried out using the differential kinetic technique previously described. The rate law for N2 evolution is of the form k1(NH4+)+k2(NH4+) (Cl—)½. A radical mechanism is proposed in which the role of chloride is catalytic, being oxidized by NO2+ to Cl atoms which are reduced back by NH4+ and NH3. These hydrogen abstraction reactions leave NH3+ and NH2, respectively, in reaction cages in which subsequent radical recombinations yield nitramide and nitrosamine as precursors for N2O and N2. Parallel Cl atom recombinations give Cl2, part of which escapes by volatilization, the rest reacting with NH3 to provide a second source of N2.

Differential rate method for kinetic measurements. Thermal decomposition of ammonium nitrate

Differential rate method for kinetic measurements. Thermal decomposition of ammonium nitrate

The thermal decomposition of ammonium nitrate: the roles of nitric acid and water

The thermal decomposition of ammonium nitrate: the roles of nitric acid and water