Vacuum pyrolysis of automobile shredder residues

A research program was undertaken to evaluate the overall performance of a vacuum pyrolysis process applied to the treatment of Automobile Shredder Residues (ASR). North American and European ASR samples were tested. Vacuum pyrolysis experiments were carried out in the temperature range of 496-536 degreesC and a total pressure of approx. 1-5 kPa. Pyrolysis product yields averaged 52.5 wt.% solid residue, 27.7 wt.%, organic liquids, 13.3 wt.% pyrolytic water and 6.6 wt.% pyrolysis gas. Composition of ASR feedstocks and pyrolysis products has been thoroughly characterized, After pyrolysis, ASR volume and weight were reduced 5 x and 1.8 x respectively. It was possible to readily recover 14 wt.% of useful metals remaining in the solid residues; the material left over can be safely landfilled. Pyrolytic gas and oil can be used as heating Fuels. The heavy fraction of the oil ( > 400 degreesC) can be added to road bitumens in order to improve their performance. The total oil also represents a challenging matrix for various purposes, The vacuum pyrolysis technology can be seen as an alternative to landfill and incineration. (C) 2001 Elsevier Science B.V. All rights reserved.