Co-pyrolysis of waste tire and larch wood in TG-FTIR

The characteristics of thermal cracking, kinetics and product gas during co-pyrolysis of different mixtures of larch sawdust and waste tire (1:2, 1:1 and 2:1) were investigated using a thermogravimetric analyzer coupled with Fourier Transform Infrared (TG-FTIR). The weight loss curves show that the process of co-pyrolysis is dominated by the larch thermal degradation before 366℃ and by the rubber thermal degradation after 366℃. The pyrolysis efficiency is improved as the ratios of larch sawdust increase. The kinetic model of Coats-Redfern was used to analyze the kinetic behaviors. It is found that the pyrolysis behavior accords with the first-order kinetics, and the activation energy in the high temperature range (370~480℃) is much smaller than that in the low temperature range (250~370℃), moreover, the pyrolysis reaction is easier to occur because the activation energy decreases with increasing the ratios of larch sawdust. The results of infrared analysis show that the organics with oxygen-containing functional groups and small molecules are main product produced. During the process of pyrolysis, the amounts of six kinds of small molecular gases produced are in the order of CO₂>CH₄>H₂O>CO>SO₂>H₂S, and S is mainly converted to SO₂ due to the effect of oxygen free radical, which is produced in the thermal degradation of larch wood.