Low-cost sorbents for demetalisation of waste oils via pyrolysis

The behaviour of several solid sorbents during the pyrolysis process of ind ustrial waste oils in a bench-scale pyrolysis unit is studied. The concentr ations of V, Ni, Pb, Cd, Cu and Cr in the waste oils and in the original so rbents as well as that obtained in the final valuable product liquid fracti on are measured. Limestone, commercial active char, Samca char, activated S amca char and sepiolite were the solid sorbents used. 100% of the lead from the waste oils can be retained on limestone. The behaviour of both metals and sorbents and the influence of specific surface area as well as chemical nature of metals and sorbents are discussed. Final liquid fractions result ed in valuable industrial products. (C) 2001 Elsevier Science B.V. All righ ts reserved.