No.2-7 低品位石炭の燃焼におけるカオリン粒子の添加による微小粒子の低減に関する研究

抄録

This paper aims to clarify the effect of kaolin addition on fly ash emission during air combustion of two low-rank coals (coal A and coal B). The raw coals were mixed with 10 wt% kaolin and then combusted in a lab-scale drop tube furnace at 1400 °C. The particle size ranges of kaolin used were < 45 μm, 45 ~ 106 μm, 106 ~ 150 μm, 150 ~ 250 μm and 250 ~ 500 μm. The resulting ash was segregated as bottom ash, fine ash (cyclone ash), and ultrafine ash (LPI ash). The influence of the particle size of kaolin added on the ash partitioning was examined. The results indicated that, adding the kaolin with the particle size of 106~150 μm during coal combustion caused the lowest fly ash emission compared to the combustion of raw coal or the mixture of raw coal and kaolin with other particle size ranges. The ultrafine ash with particle size less than 0.5 μm generated from the combustion of the mixture of coal A with the kaolin (106~150 μm) was decreased relative to raw coal combustion.