HYDROCARBON GENERATION DURING THE INERT-GAS PYROLYSIS OF AUTOMOBILE SHREDDER WASTE

When junked automobiles are shredded to recover the ferrous and non-ferrous metals, a large quantity of non-metallic waste is generated. These waste materials consist mainly of rubber and plastics. In this paper, the product yields and compositions obtained during inert gas pyrolysis of a representative shredder non-metallic waste fraction in three different experimental systems (batch thermogravimetric analyzer, bench scale batch pyrolyzer, and continuous rotary kiln) are compared. Analysis of the products by GC, HPLC, GC-MS, IR spectroscopy, H+ NMR and GPC show the presence of many hydrocarbon compounds with no single species present in large concentrations. Weight loss kinetics during the pyrolysis are also presented and discussed. The products obtained without additional processing are complex and contain compunds that prevent their direct use as a fuel in many applications. As a result, commercial exploitation of this process must await evaluation of the products obtained and, if necessary, the costs of purification and modification of the products to more useful compositions.