NOx and SO2 emissions during co-combustion of rdf and anthracite in the environment of precalciner

Abstract

Based on the temperature and O2 concentration in the cement precalciner, co-combustion of anthracite and Refuse Derived Fuel (RDF) were investigated using a thermogravimetric analyzer (TGA) and a double furnaces reactor. Both the TGA and double furnaces reactor results indicated that the co-combustion characteristics were the linear additive effect in the devolatilization stage, while it was the synergistic effect in the char combustion stage. During co-combustion, at 900 °C, NOx released rapidly during the devolatilization stage, but in the char combustion stage the NOx formation were inhibited; at 800 °C, a large amount of CO formed, which could reduce the NOx. In general, at 900 °C and 800 °C, the application of co-combustion could lower the NOx emission yield and lower the NOx conversion. By combining the combustion characteristics with the XRD results, it was indicated that during co-combustion, at 800 °C, the SO2 formation reaction was inhibited, and the SO2 yield and conversion were quite low.