Reactivity of pyrolyzed sewage sludge in air and CO2

Pyrolysis is currently being considered as an alternative method of treating sewage sludge. It yields residual oils and gases, which can be used as fuels, and a solid which can either be burned or physically activated with air or CO2. The aim of this work was to study the influence of different pyrolysis conditions (e.g. temperature and heating rate) on the reactivity in air and in CO2 of carbonaceous materials obtained from these types of residues. An anaerobic sewage sludge produced in a Spanish urban waste water treatment plant, containing 5 wt.% moisture after air-drying, was pyrolyzed in an electrical laboratory furnace under different pyrolysis conditions. Non-isothermal reactivities (up to 1100 degreesC) in air and in CO2 of the carbonaceous materials obtained after pyrolysis were performed in a thermobalance. The TG and DTG curves obtained from these experiments are discussed. (C) 2001 Elsevier Science B.V. All rights reserved.