Study on Industrial Sludge Catalytic Combustion by TGA

It is necessary to clarify the combustion process of industrial sludge in order to utilize it efficiently as an energy source. In this paper the influences of three catalysts (K
₂
CO
₃
, NaCl and Al
₂
O
₃
) on the ignition and burn off characteristics of industrial sludge had been investigated by simultaneous thermogravimetric analysis (TGA) with linearly increasing temperature at air atmosphere. The results indicated that the metallic compounds had some catalytic effects on the combustion of industrial sludge. The ignition temperature dropped in the presence of K
₂
CO
₃
, NaCl and Al
₂
O
₃
and three catalysts were all favorable for the combustion of industrial sludge. Furthermore, characteristic indexes of combustion were changed a degree correspondence to add different metals. While to the same metal, the catalytic action was also variant at different combustion stages. But in the whole process the catalytic action of K
₂
CO
₃
performed stronger than that of NaCl and Al
₂
O
₃
.The catalytic mechanism of industrial sludge combustion was distinct with adding different metal compounds. The ignition point was ahead at the beginning of combustion because the organic volatile compounds were released stimulatively with the domination of metal compounds. But at the other stages, metals serving as the carrier of oxygen made it easier for sludge combustion with the displacing and diffusing of oxygen.