PYROLYSIS KINETICS OF SCRAP TIRE RUBBERS .1. USING DTG AND TGA

Tire pyrolysis kinetics was investigated to explore an economically viable design for the pyrolysis process. Derivative thermogravimetry (DTG) and thermogravimetric analysis (TGA) were found to provide valuable information on pyrolysis kinetics and mechanisms of a heterogeneous compound like scrap tire rubbers. Kinetic parameters of each compositional compound were obtained by analyzing DTG and TGA results with a series of mathematical methods proposed in this study. The pyrolysis kinetics of the scrap tire rubbers tested was well accounted for by the first-order irreversible independent reactions of three compositional compounds. The sidewall and tread rubber exhibited different thermal degradation patterns, suggesting a compositional difference between them. Isothermal pyrolysis results showed that the sidewall rubber would hardly be degraded at low temperature regions (<600 K), whereas it would be more rapidly degraded than the tread rubber at higher temperatures (greater than or equal to 746 K). Because of the shorter pyrolysis time, the higher isothermal pyrolysis temperature appeared to be more economically favorable.