Effects of sewage sludge blending on the coal combustion:: A thermogravimetric assessment

Combustion of urban sewage sludge together with coal in existing infrastructures may be a sustainable management option energetically interesting, for these materials, usually considered wastes. Thermogravimetric analysis was used to study the combustion of a semi-anthracite coal and the modifications undergone when adding a small percentage (2%, 5%, 10%) of sewage sludge. Both Differential Scanning, Calorimetric analysis and Differential Thermogravimetry burning profiles showed differences between coal and sewage sludge combustion. However. the effects of adding a percentage of sewage sludge equal or smaller than 10% was hardly noticeable in terms of heat release and weight loss during the coal combustion. This was further proved by non-isothermal kinetic analysis, which was used to evaluate the Arrhenius activation energy corresponding to the co-combustion of the blends. This work shows that thermogravimetric analysis may be used as an easy rapid tool to asses the co-combustion of sewage sludge together with coal. (C) 2007 Elsevier Ltd. All rights reserved.