神木煤流化床气化带出细粉的特性

摘要

采用灰熔点测定仪、扫描电镜-能谱分析仪和热重分析相结合，研究了神木煤流化床气化带出细粉的灰熔融特性、粒径分布和气化反应活性。结果表明，神木煤流化床气化带出细粉中酸性成分的减少和碱性成分铁、钙等的增加，使神木煤流化床气化带出细粉的灰熔点比原煤低。神木煤流化床气化带出细粉具有较宽的粒径组成，呈现出明显的多峰状分布，带出细粉表面的元素分布存在很大的差异。随着带出细粉粒径的减小，细粉中的水分逐渐减少，灰分含量逐渐增大。气化飞灰的孔隙结构比高温煤焦更发达，具有比较丰富的中孔和大孔，导致带出细粉的反应活性比神木煤焦高。%The ash fusion characteristics, particle-size distribution and gasification reactivity of Shenmu coal (SM) fine chars from ash agglomerate fluidized bed gasification were explored by ash fusion point analyzer,scanning electron microscopy equipped with energy dispersive X-ray analysis ( SEM-EDX), and thermo-gravimetric analyzer. The results show that the decrease in basic ingredients (e. g. iron and calcium) and theincrease in acidic ingredients make the ash fusion temperature (AFT) of SM fine chars lower than that of SM. There is a wide particle-size distribution in SM fine chars, which shows a significant multi-peak distribution, anda large difference of the elemental distribution in fine char particles with different sizes. The moisture content is lower and ash content is higher in fine power than that in SM, respectively. SM fine char has higher surface areathan that of SM char , and relatively rich in meso-pores and macro-pores, which results in its higher gasification reactivity than SM char.