Journal of Analytical and Applied Pyrolysis 58–59 (2001) 927–941 Analysis of the pyrolysis and combustion of different sewage sludges by TG R. Font *, A. Fullana, J.A. Conesa, F. Llavador Departamento de Ingenierı ´a Quı ´mica, Uniersidad de Alicante, Apartado Correus 99, 03080 Alicante, Spain Received 7 April 2000; accepted 14 August 2000 Abstract The pyrolysis and combustion of seven samples of sewage sludge were studied by TG dynamic runs carried out at 15°C min -1 . Two different behaviors were observed. For some samples, considering the variations of weight loss versus temperature or time, the combustion thermograms are similar to those of pyrolysis but with a displacement of the corresponding curves of combustion to temperature intervals less than those of the pyrolysis runs. For the other samples, the pyrolysis thermograms coincide with the combustion thermograms, except in the last part of the combustion thermogram where a final decomposition appears as a consequence of the combustion of the char previously formed. The different behavior can be associated to aerobic stabilization of the samples. Some runs were also done with acid- washed samples to test the influence of the metal content. © 2001 Elsevier Science B.V. All rights reserved. Keywords: Sewage sludge; Pyrolysis; Combustion www.elsevier.com/locate/jaap 1. Introduction It is estimated that the average production of dehydrated sewage sludge is around 0.2 – 0.3 kg per (inhabitant day). The production of sludge in 1992 corresponding to Spain was 350 000 t dry matter per year, and with a growth prevision to 600 000 t dry matter per year for the year 2005. The estimated production of sludge for the year 2005 for the European Union is around 8–10 Mt dry matter per year [1]. * Corresponding author. Tel.: +34-96-5903546; fax: +34-96-5903826. E-mail address: rafael.font@ua.es (R. Font). 0165-2370/01/$ - see front matter © 2001 Elsevier Science B.V. All rights reserved. PII:S0165-2370(00)00146-7