Effect of particle size on the kinetics of pure oxygen combustion of coke

Non-isothermal thermogravimetry technique was used to analyze three groups of coke samples (S-ZD, M-ZD, and L-ZD) of varying particle sizes. The effect of particle size on kinetic parameters was studied in a pure oxygen atmosphere. The ignition (T-i), peak (T-y), and burnout (T-f) temperatures and the flammability (C) and combustion characteristic (S-n) indexes were determined by varying the heating rate (beta). The activation energy (E-alpha) was evaluated following the Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) methods. T-i, T-p, T-f, C, and S-n correlated positively with the increase in beta in a pure oxygen atmosphere. The order of ignition was L-ZD > M-ZD > S-ZD, and the E-alpha values for the S-ZD, M-ZD, and L-ZD samples were 98.49, 98.35, and 95.17 kJ.mol(-1) (FWO) and 90.32, 90.92, and 89.25 kJ.mol(-1) (KAS), respectively. Particle size exerted little effect on the kinetics of coke combustion.