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2,4,6-Trinitrotoluene (TNT), as a representative component of explosive wastewater, is treated in supercritical water gasification (SCWG) and supercritical water oxidation (SCWO) using molecular dynamic simulations based on ReaxFF reactive force field as well as density functional theory (DFT). The detailed reaction processes, important intermediates and products distribution, and kinetic behaviors of SCWG and SCWO systems have been analyzed at the atomistic level. For the SCWG system, TNT is activated by water cluster or H radical and the N atom is mainly converted into NH 3 more than N 2 through two significant intermediates NOH and C−N fragment. In addition to water cluster and H radical, the TNT is activated by O 2 in the SCWO system. Besides, the N atom is transferred into N 2 more than other N-containing products after 750 ps simulation. Combined with the calculated cracking energy of the bonds in TNT, SCWG can accelerate its degradation and is easier for C−N bond breaking or changing through other reactions because of its low cracking energy (69.6 kcal/mol in thermal decomposition and 59.0 kcal/mol in SCWG). In addition, a large amount of H 2 molecules is produced in SCWG, which is a meaningful way of transforming waste to assets. On TNT degradation, SCWO with inadequate O 2 that can be treated as partial oxidation reaction (SCWPO) can combine the advantages of SCWG and SCWO (with enough O 2 ) to convert TNT into CO 2 , H 2 O, as well as H 2 and NH 3 with high economic value. Finally, a kinetic description is performed whose activation energies (17.6 and 18.4 kcal/mol) are theoretically consistent with experimental measurements.

A pilot polygeneration process of a 75 t h -1 circulating fluidized bed (CFB) boiler combined with a moving bed coal pyrolyzer was developed based on laboratoryscale experimental results. The process operation showed good consistency and integration between boiler and pyrolyzer. Some critical operating parameters such as hot ash split flow from the CFB boiler to the pyrolyzer, mixing of hot ash and coal particles, control of pyrolysis temperature and solid inventory in the pyrolyzer, and pyrolysis gas clean-up were investigated. Yields of 6.0 wt-% tar and 8.0 wt-% gas with a heating value of about 26 MJ m -3 at 600°C were obtained. Particulate content in tar was restrained less than 4.0 wt-% by using a granular filter of the moving bed. Operation results showed that this pilot polygeneration process was successfully scaled up.