胜利褐煤半焦显微结构及其燃烧反应性能

利用固定床反应装置对胜利褐煤在650 ℃进行热解，所得半焦在光学显微镜下分选出惰质组占73.40%的丝质相和腐殖组占98.67%的木质相两种显微结构相组分。利用热分析考察了两种显微结构的燃烧反应性能，分析了燃烧特征参数如起燃指数、燃烬指数等，并回归得到其动力学。研究表明，丝质相为多孔状，木质相为致密状，前者比表面积约为后者的21倍；丝质相的燃烧反应性显著高于木质相；均相和缩芯模型对两类煤焦燃烧反应过程都能进行准确描述，丝质相在起燃阶段的活化能显著低于木质相，是丝质相燃烧反应性高的内在原因。

Microscopic structures of semi-coke of Shengli lignite and its combustion reactivity

Shengli lignite was pyrolyzed under 650 ℃ in a fixed-bed reactor.Fusinitic coal (containing 73.40% inertinite) and xyloid coal (containing 98.67% huminite) were separated under semi-coke using optical microscope.The combustion reactivity,in terms of combustion parameters such as ignition index,burn out index,was calculated by thermogravimetric analysis.The combustion kinetics of both fusinitic coal and xyloid coal were regressively calculated.The results show that fusinitic coal and xyloid coal possess porous structure and compact structure respectively.The specific surface area of fusinitic coal is 21 times larger than that of xyloid coal.The combustion reactivity of fusinitic coal is much higher than that of xyloid coal in the “burn out” condition.Both the homogeneous and the shrinking core model can regressively fit the combustion processes of fusinitic coal and xyloid coal accurately.The activation energy of fusinitic coal is much lower than that of xyloid coal,which is the essential reason for higher combustion reactivity of fusinitic coal.