Kinetic aspects of SCWO progress of solid organic substances

The specific surface reaction rates of Breasol coal and styrene–divinylbenzene resin particles in sub and supercritical water with O2O2 were investigated in the temperature range of 300–450∘C at 25 MPa by observing the size change using a shadowgraph method. The rates were approximately proportional to the O2O2 concentration and non-linearly dependent on the flow rate. The rate obeyed the Arrhenius law at lower temperatures, but became gradually independent on the temperature above 400∘C, which indicated that the overall reaction is controlled by a certain mass transfer process at the higher temperatures. Compared with the case of coal and activated carbon, much smaller amount of O2O2 is enough to result in the rapid size decrease rate in the resin particle.