Application of gas-liquid film theory to base hydrolysis of HMX powder and HMX-based plastic-bonded explosives using sodium carbonate

Sodium carbonate (Na2CO3) is identified as a hydrolysis reagent for decomposing HMX and HMX-base explosives to water-soluble, nonenergetic products. The reaction kinetics of Na2CO3 hydrolysis are examined, and a reaction rate model is developed. Greater than 99% of the explosive at an initial concentration of 10 wt % PBX 9404 was destroyed in less than 5 min at 150 degrees C. The primary products from Na2CO3 hydrolysis were nitrite (NO2), formate (HCOO-), nitrate (NO3-), and acetate (CH3COO-) ions, hexamethylenetetramine, (hexamine: C6H12N4), nitrogen gas (N-2), nitrous oxide (N2O), and ammonia (NH3). The rate of hydrolysis was characterized for HMX powder and PBX 9404 molding powder from 110 to 150 degrees C. The rate was found to be dependent on both the chemical kinetics and the mass transfer resistance. Since the HMX particles are nonporous and external mass transfer dominates, gas-liquid film theory for fast chemical kinetics was used to model the reaction rate.