Experimental Research on Catalytic Combustion Characteristics of Inferior Coal and Sludge Mixture

Abstract

Catalytic effects of metal oxides on combustion characteristics of inferior coal, sludge, and their mixture were investigated by thermogravimetric analysis. Combustion and thermal dynamic characteristics including ignition temperatures, apparent activation energy, and frequency factors of inferior coal, sludge, and their mixture were observed. The catalytic effects and mechanism of combustion were discussed. Results showed that thermal gravity analysis (TG) and derivative thermogravimetric analysis (DTG) curves of coal and sludge shifted to lower temperature side, the weight losses increased, and the ignition performance was improved with the addition of metal oxides CaO, Al2O3, and K2O. The combustion dynamics analysis showed that the apparent activation energy of cocombustion of coal blending sludge decreased by 11–20% and the frequency factors increased by 20–30%. The minimum apparent activation energy and the maximum frequency factors were obtained in the presence of K2O, indicating that the catalytic effect of K2O was most significant.