Thermal Analysis of Municipal Sludge Waste Combustion

Abstract

Municipal sludge waste combustion was studied by thermogravimetry (TG) and differential thermal analysis (DTA), to better understand the two main stages which occur during the combustion process, and to evaluate how much of the total and significant generated heat is released is during each combustion stage. A method to measure the lower heating value (LHV) on a dried basis was developed from the TG/DTA data and it was applied to the whole process and to each combustion stage. Chemical analysis of the residual products after each step shows that nitrogen organic compounds are burnt only from 350°C to 550°C, and that the organics which are released and burnt in the previous step, which begins by 150°C, present a heating value of about 32MJ/kg. The nitrogen containing compounds present a lower LHV.