Decomposition kinetics of dimethyl methylphospate(chemical agent simulant) by supercritical water oxidation

摘要

Supercritical water oxidation (SCWO) has been drawing much attention due to effectively destroy a large variety ofhigh-risk wastes resulting from munitions demilitarization and complex industrial chemical. An important design consideration in thetdevelopment of supercritical water oxidation is the information of decomposition rate. In this paper, the decomposition rate oftdimethyl methylphosphonate(DMMP), which is similar to the nerve agent VX and GB(Sarin) in its structure, was investigated under SCWO conditions. The experiments were performed in an isothermal tubular reactor with a H_2O_2 as an oxidant. The reactiontjtemperatures were ranged from 398 to 633 deg C at a fixed pressure of 24 MPa. The conversion of DMMP was monitored by analyzingtItotal organic carbon (TOC) on the liquid effluent samples. It is found that the oxidative decomposition of DMMP proceeded rapidlytand a high TOC decomposition up to 99.99 percent was obtained within 11 s at 555 deg C. On the basis of data derived from experiments, a global kinetic equation for the decomposition of DMMP was developed. The model predictions agreed well with the experimental data.