Co-combustion kinetics of sewage sludge with coal and coal gangue under different atmospheres

In this paper, the co-combustion behaviour of sewage sludge with coal gangue and coal were investigated by a thermogravimetric analysis (TGA) in the temperature range from ambient temperature to 1000 °C. Experiments were carried out with about 10 mg of sample in five different atmospheres: 20% oxygen in nitrogen, 30% oxygen in nitrogen, 40% oxygen in nitrogen, 60% oxygen in nitrogen and 70% oxygen in nitrogen, thermogravimetry (TG) and DTG curves were analyzed. A method of direct non-linear regression of the kinetic equation was used to a simultaneous calculation of the kinetic parameters (the apparent activation energy, the reaction order and the frequency factor) from a single TG curve in various atmospheres. The results indicate that: with the increase of heating rate the maximum weight loss rate of samples increase obviously. The activation energy values range from 51.2 kJ mol−1 to 164.4 kJ mol−1.