Pyrolysis properties of municipal sewage sludge

Thermogravimetric analyses (TGA) and difference scanning calorimeter (DSC) were used to study the combustion characteristics of dried sludge from the Beijing Gaobeidian Sewage Treatment Plant. The result showed there are three temperature ranges during the sludge combustion, in which the sludge quickly lost weight. The first two are due to release of the volatiles, while the fixed carbon is combusted in the third range. The kinetics parameters for the chemical reactions were calculated and the sludge combustion mechanism is discussed. Some suggestions are given for the design of sludge fluidized bed incinerators.