神华烟煤煤粉中低温热解半焦的粒径和形态特性  

Particle size and morphological characteristics of char obtained from low-temperature pyrolysis of pulverized Shenhua bituminous coal

作　　者：葛冬冬 黄镇宇[1] 王智化[1] 刘建忠[1] GE Dong-dong HUANG Zhen-yu WANG Zhi-hua et al(State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China)

机构地区：[1]浙江大学能源清洁利用国家重点实验室,浙江杭州310027

出　　处：《能源工程》2017年第5期1-7,共7页Energy Engineering

基　　金：基金项目:国家重点基础研究发展规划(2012CB214906)

摘　　要：选择挥发分较高的神华烟煤煤粉用固定床反应器进行300℃至700℃的中低温热解,使用筛分法研究半焦颗粒粒径变化,结合扫描电子显微镜、傅里叶红外光谱和低温氮吸附考察半焦颗粒的微观形态、官能团和孔隙结构变化,讨论颗粒尺寸变化的机理。结果表明,颗粒粒径随温度升高而减小。在温度低于400℃时,活泼的热解反应尚未进行,由于水分和少量挥发物的析出导致部分中孔孔隙收缩,此时半焦粒径轻微减小,且主要是粒径较大的发生轻微变化;热解温度升高到500℃及以上,在加剧的缩聚反应作用下,颗粒粒径剧烈减小,内部孔径分布变化加剧,同时收缩产生的裂痕促使更多碎块产生,进一步减小了颗粒的粒径。The pulverized Shenhua bituminous coal was pyrolyzed from 300 ℃ to 700 ℃ using a fixed-bed reactor. Sieve analysis was used to investigate changes in char particle size. SEM, FTIR and N2 adsorption were employed to in- vestigate changes in surface morphology, chemical structure and pore structure of the char particles, and the mecha- nisms of particle size change were discussed. Results suggested that the char particles tended to become finer with in- creasing pyrolysis temperature. When the pyrolysis temperature was below 400 ℃ , active pyrolysis reactions did not oc- cur and some mesopores collapsed because of the shrinkage forces caused by removal of moisture and a limited release of volatile matter. In this stage, the particle size slightly decreased and the particle size changed mainly occur to those with larger particle size. When the pyrolysis temperature increased beyond 500 ℃ , the decrease in particle size was significantly sharper than those below 500 ℃ as a result of greater extent of condensation reactions at high tempera- tures. Pore structure changed significantly at this stage and contraction of the particles form more fractures and cracks on char surfaces, which could further reduce particle size by generating small particle fragments.

关 键 词：烟煤 热解 半焦 粒径 形态 

分 类 号：TK16[动力工程及工程热物理—热能工程]