The Kinetics of Decomposition of Liquid Ammonium Nitrate

Abstract

ions. In the former instances, the SnI mechanism predominates, and the rate-determining step is the formation of a carbonium ion which then reacts readily with an anion to form the product. By such a mechanism, it is evident why cellulose, with its very weakly ionized hydioxyl groups, does not react with the epoxides to form cellulosic ethers readily in the presence of large concentrations of hydrogen ions.However, if the Sn2 mechanism predominates, as in the instance of low concentrations of hydrogen ions and in the presence of Zn+2 ions, the cellulose molecules can compete with water or other solvent molecules in a bimolecular reaction with the conjugate acid of the epoxide in the slow rate-determining step.

Study of the decomposition of phase stabilized ammonium nitrate (PSAN) by simultaneous thermal analysis: determination of kinetic parameters

“…Despite the Ozawa±Flynn±Wall method being less accurate than the Friedman method, the results con®rm its validity for the process under study. Several studies [17,19,20] on the kinetics and mechanisms of the thermal decomposition of AN have revealed that the main products N 2 O and H 2 O result from the exothermic decomposition reaction…”

“…This coupling is both kinetic and thermal. The thermal behavior (endothermic or exothermic) that prevails in the overall process depends on several experimental factors [17,20]. In the absence of conditions favorable to the occurrence of an auto-catalytic regime and a consequent thermal run-away, the heat produced by the exothermic decomposition as well as heat supplied by an external source if exists may be absorbed by the dissociation reaction.…”

“…A great deal of work has been done on the kinetics and mechanisms of decomposition whose possible variety seems to strongly dependent on the experimental conditions such as the pressure, sample size, state of con®nement, heating rate, and the presence of traces of impurities or additives [14]. This can explain to some extent the surprisingly wide range of activation energy values reported for the thermal decomposition of AN, ranging from 118 [15] to 171.5 kJ mol À1 [17]. These studies have been carried out under different experimental conditions, possibly by means of experimental setups speci®cally designed to reach a restricted goal.…”

Thermal decomposition of solid mixtures of 2-oxy-4,6-dinitramine-s-triazine (DNAM) and phase stabilized ammonium nitrate (PSAN)

“…0.001 mol l À1 aqueous solution, with 0.1 mol l À1 NaOH, at room temperature) [16]. On the other hand, when AN is heated two major reactions are involved [11,17,18]: the endothermic dissociation NH 4 NO 3 NH 3 HNO 3 (1) and the exothermic decomposition…”

“…(2) re¯ects a net reaction and several breakdown mechanisms have been proposed [5,6,8± 11]. For the present discussion, is enough to consider the generally accepted ionic mechanism that prevails at temperatures below 3008C, according to which the decomposition of AN is inhibited by both H 2 O and NH 2 , while HNO 3 has a catalytic effect [9,11]. Considering that DNAM may have the capability of shifting the acid±base equilibrium (Eq.…”