Co-combustion characteristics of municipal sewage sludge and bituminous coal

The co-combustion characteristics of municipal sewage sludge and bituminous coal in air and O-2/CO2 atmospheres were assessed by using a thermogravimetric analysis approach between heating rates of 20 and 80 K min(-1). The combustion characteristics of sewage sludge/bituminous coal blend (50% blending ratio) in air were also compared with its oxy-fuel behavior. In air atmosphere, the ignition temperatures for sludge/coal blends were between those for their parent samples, which ranged from 238 to 418 A degrees C. In O-2/CO2 atmosphere with oxygen content of 30%, the ignition temperatures of 50%sewage sludge/50%coal blend were between 260 and 275 A degrees C, which were less than those (268-280 A degrees C) in air. The ignition and burnout indexes of the sample in 30%O-2/70%CO2 atmosphere were very close to those in air. The temperatures with respect to maximum combustion rates of the 50%sewage sludge/50%coal blend in 40%O-2/60%CO2 were lower than those in air. The average value of the activation energy for the 50%sewage sludge/50%coal blend in 30%O-2/70%CO2 was less than that in air.