Hydrothermal Treatment of C−N−O−H Wastes:  Reaction Kinetics and Pathways for Hydrolysis Products of High Explosives

Abstract

Bench-scale studies demonstrated the efficacy of hydrothermal oxidation for the treatment of wastes derived from the alkaline hydrolysis of the high explosive PBX 9404 (94% HMX, 3% nitrocellulose, and 3% chloroethyl phosphate). Specifically, chemical kinetics studies were used to deduce major global reaction pathways, and to develop a kinetic model. Although the hydrolysis liquor is a complicated waste matrix, a three-parameter kinetic model captured major reaction paths. The kinetic model used total organic carbon (TOC) as a bulk parameter for dissolved organic materials, while NO x - was used to represent the oxidized nitrogen species in solution (NO2 - and NO3 -). With the use of the kinetic model, an optimal treatment strategy using two oxidation stages was derived. The first stage involved balancing NO x - and O2 redox chemistry to minimize aqueous nitrogen in the effluent, while the second stage mineralized the remaining TOC.

Removal of C.I. Basic Blue 41 from aqueous solution by supercritical water oxidation in continuous-flow reactor

“…Supercritical water oxidation (SCWO) shows a substantial promise for clean and efficient decontamination of many aqueous organic wastes [19][20][21][22][23][24][25][26][27][28]. SCWO can rapidly and efficiently destroy organic substances into H 2 O and CO 2 in significantly short residence times.…”

Hydrothermal Treatment of C−N−O−H Wastes: Model-Based Reactor Effluent Control

“…Steady-state design calculations indicate a significant reduction in the effluent aqueous nitrogen compounds with the use of two peroxide injection points. 4 The typical residence time in the reaction section is between 4 and 10 min.…”

“…The simplified hydrothermal oxidation reactions in the reduced kinetic model provide an adequate representation of the effluent aqueous nitrogen concentrations for the experimental data used to generate the model parameters. 4 Because the kinetic model is a…”

Modeling of a Porous Reactor for Supercritical Water Oxidation by a Residence Time Distribution Study

“…In particular, no pollutant such as NO x is encountered in the gaseous effluent. [5][6][7] However, the development of SCWO applications is limited by two main problems encountered in such a process. SCWO generates such aggressive environments with oxidant and mineral acids that any material suffers from corrosion attack.…”

“…in the liquid phase and carbon dioxide as well as molecular nitrogen in the gas phase. In particular, no pollutant such as NO x is encountered in the gaseous effluent. − However, the development of SCWO applications is limited by two main problems encountered in such a process. SCWO generates such aggressive environments with oxidant and mineral acids that any material suffers from corrosion attack. − To prevent the reactor from corrosion, alkalis are usually added as neutralization reagents.…”