Pyrolysis of Waste Tire Powder and Its Comparison with Shenhua Coal

The pyrolysis process of typical Chinese waste-tire powder of 74-250 ¿m was experimentally studied by TG/DTG at different heating rates and was compared with that of coal Shenhua. The results showed that the main weight-loss process can be divided into three phases during the pyrolysis, i.e., the thermal decomposition of the oil-mixture, moisture, plasticizers and other additives, the decomposition of natural rubber and then the decomposition of polybutadene (BR) and polybutadene-styrene (SBR) as the temperature increased. The weight loss would increase with the heating rate and the TG curve began to move to the right with the increase of the starting and ending temperatures for the reaction, though the percentage of the final weight loss may not change so obviously. The DTG curve also moved to the right as the heating rate increased. The pyrolysis index defined by the maximum weight loss rate and the corresponding temperature would also increase, which was actually expected to release volatile gas more and faster. However, the particle size has very little effect on the pyrolysis if it is less than 1mm. The comparison showed that the beginning temperature of pyrolysis for the tire powder was usually lower than that of coal. The maximum weigh loss rate of tire was larger than that of coal and more volatile gases was released by tire than coal at the same heating condition. The above results have thus provided some basic data for the tire combustion technology.