Abstract: Three types of plastic particles, polypropylene (PP), high-density polyethylene (HDPE), and polystyrene (PS), were selected and mixed in different proportions, and the thermogravimetric apparatus was used to analyze the pyrolysis temperature range and weight loss of the separate and mixed samples of the three types of plastics. Friedman, KAS and finite parallel reaction model were used to solve the pyrolysis reaction kinetic parameters of plastics. The results demonstrated that the order of pyrolysis reactions of several plastic samples from easy to difficult and the order of average activation energy calculated by Friedman and KAS method from small to large of several plastic samples followed: PS＜PP-PS＜PP-HDPE-PS(1:1:1)＜HDPE-PS＜PP-HDPE-PS(actual proportions)＜PP＜PP-HDPE＜HDPE. The activation energies of PP, HDPE, PS, PP-HDPE, PP-PS, HDPE-PS, PP-HDPE-PS(1:1:1) and PP-HDPE-PS (actual proportions) plastic samples estimated by the finite parallel reaction model were concentrated in the range of 198–314, 231–317, 192–297, 200–314, 194–299, 186–301, 171–242 and 196–312 kJ/mol, respectively.

Key words: pyrolysis reaction, kinetic analysis, finite parallel reaction model, Friedman method, KAS method