ojce.01.2018.04.07

Thermo gravimetric (TG) experiments of sludge can reflect the drying and combustion characteristics of material for exactly obtaining the mechanism of drying and combustion processes. The weight loss process of wet sludge includes three stages: drying stage, flammable stage and non-flammable sage. The Paper conducts thermo gravimetric test and kinetic parameter calculation for these three stages. The weight loss and drying process of sludge consists of five stages: preheating stage, rapid weight loss stage, constant-rate weight loss stage, decelerating weight loss stage I and decelerating weight loss stage. This Study carried out more detailed division of multi-stages than the previous on drying and combustion process to Chinese southern municipal sludge. The kinetic process for the drying and for the combustion of sewage sludge should be expressed by phase interface reaction mechanism function g(a)=1-(1-a)n and chemical reaction equation f(a)=(1-a)n respectively. Kinetic parameters reveal that activation energy decreases in the sequence of non-flammable stage, flammable stage and drying stage, and when changing the heating rate, the activation energy changes significantly in flammable stage while nearly remains unchanged in non-flammable stage.