Effect of the Particle Size on Co-combustion of Municipal Solid Waste and Biomass Briquette under N-2/O-2 and CO2/O-2 Atmospheres

摘要

The combustion characteristics and kinetics of municipal solid waste and biomass briquette blend were investigated at different particle sizes using thermogravirnetric analysis. For the comparison between N-2/O-2 and CO2/O-2 atmospheres, the mole fraction of oxygen was 20% and effects of the heating rate on the blend combustion behavior were also evaluated. Results showed that, in the range of less than 270 mu m, the most vigorous combustion occurred at a particle size of 150-180 mu m, regardless of the heating rate. With the increase of the heating rate, the combustion intensity of the blend could be improved and the reaction process was influenced to some extent. The replacement of N-2 with CO2 reduced the combustion reactivity and had a significant effect at the particle sizes of less than 106 mu m. The maximum values of activation energy (E) occurred at 150-180 mu m, which corresponded to the maximum comprehensive combustion characteristic index S. The E values under an 80CO(2)/20O(2) atmosphere were close to those under an 80N(2)/20O(2) atmosphere in the first and second reaction stages, but the differences of E values in the third stage were larger, with a maximum of 114.79 kJ/mol. The results obtained from this work can help to optimize the parameters of municipal solid waste and biomass briquette co-combustion equipment and provide reference for the blend combustion under oxy-fuel combustion technology.