(2008) An investigation of the thermal degradation mechanism of waste tires through chemical analysis at high temperature

Kwon E., Castaldi M.J.

() Air and Waste Management Association - 27th Annual International Conference on Thermal Treatment Technologies 2008 Vol.2 

Previous work has focused on a series of fundamental Thermo-Gravimetric Analysis (TGA) studies using various representative atmospheres found in Waste-to-Energy (WtE) boilers. Those studies were done for waste tires and their major constituents, such as Styrene-Butadiene Copolymer (SBR) and Poly-Isoprene (IR). The outcome has been the elucidation of the likely mechanism responsible for initial decomposition, and final product and byproduct formation. To extend that understanding to a more practical level; a flow-through apparatus has been used to test waste tire samples and main constituents (SBR and IR) in the temperature range of 500°C-800°C. Reaction atmospheres consisted of air to simulate combustion and N2 to simulation pyrolysis conditions. The release of chemicals from a tubular quartz reactor containing a tire sample has been determined experimentally using GC/MS. Significant levels of Volatile Organic Carbons (VOCs) including benzene derivatives, PAHs, and Hetero-N containing PAHs were observed. This flow-reactor system was designed to better simulate a waste combustor by introducing the waste tire sample into a combustion zone pre-heated to the desired test temperature. This study identifies and quantifies the chemical species, which evolved from the thermal degradation of tires, SBR, and IR, to provide new data for the overall development and validation of detailed reaction mechanisms in a laboratory scale flow-reactor.