Thermogravimetric and pyrolytic investigations on scrap tires

Thermogravimetric, TG, analysis of scrap tire (ST) powder indicated that it decomposes between 180 and 475 °C losing 60% of its weight in two step process. The material further decomposes to end up with only ∼3.8% residual products at 680 °C. Potassium carbonate slightly affected the modes of scrap tires decomposition. On the basis of the TG results pyrolysis, experiments were carried out coupled with gas chromatographic analysis of the volatiles and trapping of the condensed liquids. The pyrolytic investigation was performed in a pyrex vertical reactor with sintered glass disc to hold the sample and aid fluidization with the nitrogen stream flowing upwards. Tar and char are collected and weighed. The effect of pyrolysis temperature and the presence of potassium carbonate on the tar, char and gas yields were studied. The C1–C3 content of the pyrolysis gases increased from 0.17% to 60.1% by increasing the pyrolysis temperature from 470 to 550 °C at the expense of the C4 and C5 components. Further, there was an increase in the hydrogen content of gaseous components with pyrolysis temperature increase.