Vacuum pyrolysis of automobile shredder residues: use of the pyrolytic oil as a modifier for road bitumen

The physicochemical properties and the rheological behavior of the pyrolytic oil residue obtained from the vacuum pyrolysis of automobile shredder residues have been studied. The pyrolysis experiments were performed batchwise in a large retort. The pyrolytic oil residue (boiling point > 400 degrees C) was found to have a low concentration in aromatic hydrocarbons and exhibited a moderate penetration, high softening point and low dynamic viscosity. A rheological characterization revealed that the viscoelastic behavior of this oil residue was similar to that of petroleum bitumens. Addition of the pyrolytic residue (PR) to petroleum bitumens improved the road bitumen performance such as rutting, shown by the G*/sin delta ratio, and the volatility, as indicated by the weight loss method. The pyrolytic residue enhanced the high service-temperature by reducing the thermal susceptibility of the pure bitumen. (C) 1999 Elsevier Science B.V. All rights reserved.