Thermogravimetric Analysis and Kinetics of Mixed Combustion of Waste Plastics and Semicoke

The thermogravimetric method was applied to study the combustion characteristics of waste plastics and semicoke mixture at different heating rates with temperature ranging from room temperature to 1173 K. Also, the kinetic parameters of combustion process were also estimated by fitting the experimental data to the calculated data. The results showed that the mixed combustion process of waste plastics and semicoke could be divided into volatile combustion stage and fixed carbon combustion stage. The addition of waste plastics could increase the comprehensive combustion characteristic index ( S ) and flammability index ( C ). It showed synergistic effect in the mixed combustion process. When the additive amount of waste plastics was 60%, the S value and C value reached peak point at the heating rate of 20 K/min. The heating rate had a promotion effect on combustion rate. The mixed combustion process of waste plastics and semicoke could be well simulated by the n-order rate model of double parallel reactions. The activation energies E in the first stage of combustion of the mixture were higher than that in the second stage, and the preexponential factor k was opposite. Meanwhile, a marked kinetic compensation effect was presented between the activation energy and the preexponential factor.