Safe Operating Temperatures for Pressurized Alkaline Hydrolysis of HMX-Based Explosives

Abstract

Alkaline hydrolysis is used to convert high explosives to nonenergetic, aqueous compounds. Base hydrolysis of high explosives is exothermic (∆H RXN ) 2.3 kJ/g), and thermal runaway of the reaction is a possibility at elevated temperatures (>120 °C) where the rate of reaction is large. Thermal runaway could result in an accidental detonation of the energetic material being treated, so safe operating parameters for base hydrolysis need to be determined. To measure the safe operating temperature, base hydrolysis was performed at temperatures ramped from 20 to 300 °C. The results show that PBX 9501 molding powder detonates at a 185 °C bulk temperature in 1.5 M NaOH with a 4.5 °C/min linear temperature ramp and no agitation. The reaction of pressed PBX 9501 with 0.75, 1.5, and 3.0 M NaOH and water and both pressed and nonpressed PBX 9404 with 0.75, 1.5 M, and 3.0 M NaOH and water did not produce a detonation with a 4.5 °C/min linear temperature ramp. A previously developed reaction rate model was used to show that thermal runaway should occur when the base hydrolysis reaction rate reached a maximum at a bulk temperature between 185 and 225 °C.

Soils contaminated with explosives: Environmental fate and evaluation of state-of-the-art remediation processes (IUPAC Technical Report)

“…4,6-Dinitro-2,4,6-triazahexanal and 5-hydroxy-4-nitro-2,4-diaza-pentanal were identified as by-products leading to the formation of the ring cleavage product 4-nitro-2,4-diazabutanal. The efficacy of alkaline hydrolysis may be enhanced with an increase in reaction temperature [51][52][53][54], however, thermal runaway may occur at temperatures greater then 120 °C [53].…”

Alkaline hydrolysis of hexahydro-1,3,5-trinitro-1,3,5-triazine: M06-2X investigation

“…This process is accompanied by releasing of large amount of energy, that provides evidence in favor of its irreversibility. Exothermicity of the nitrous acid elimination from cyclic nitramines is experimentally and theoretically supported (Bishop et al, 2000;Hawari et al, 2002;Zhang et al, 2011). Existence of INT2 in decomposition pathway of RDX was tentatively identified in several experimental studies (Hoffsommer et al, 1977;Hawari et al, 2002;Balakrishnan et al, 2003).…”

Shrinking Particle Reaction Model for a Waste Double‐Base Propellant During Alkaline Hydrolysis

“…This result is similar to the alkaline hydrolysis of other energetic materials (such as NC, NG, and HMX-base explosive, etc.) [15,17,23,24,36]. As shown in Figure 9, the alkaline hydrolysis rate of SC granules was unaffected by the stirring speed.…”

“…Furthermore, Raeisi and Najafpour [20] showed that pure cellulose could be recovered from NC waste using NaOH. Therefore, alkaline hydrolysis is a promising alternative to OB/OD methods of waste propellant disposal [9,19,[21][22][23][24].…”