煤裂解或燃烧条件下汞的析出规律研究  

Mercury Transformation during Coal Combustion and Pyrolysis

作　　者：周劲松[1] 骆仲泱 任建莉[1] 岑可法[1] 

机构地区：[1]浙江大学热能工程研究所,杭州310027

出　　处：《燃烧科学与技术》2002年第2期103-108,共6页Journal of Combustion Science and Technology

基　　金：国家自然科学基金资助项目 (5990 60 1 0 );国家重点基础研究发展规划资助项目 (G1 9990 2 2 2 1 2 )

摘　　要：进行了加热时间、反应条件、煤种等因素影响煤中汞析出规律的试验研究。首先对煤样裂解或燃烧产物中残留汞进行分析 ,发现煤中汞在燃烧条件下能很快析出 ,而在裂解时则析出相对缓慢。其次利用管式炉系统 ,在还原性气氛 (载气为氮气 )或氧化性气氛 (载气为氮、氧体积比为 4∶ 1的混合气体 )下进行煤样裂解或燃烧后汞的析出及形态迁移转化试验。研究认为 ,煤在裂解或燃烧后 ,汞主要以气态方式进入烟气 ,烟气中的汞主要以二价汞(Hg2 + )和零价汞 (Hg0 )形式存在 ,且汞的形态分布与反应条件和煤种有关。随加热温度升高 ,烟气中的二价汞含量升高 ,零价汞含量降低 ;裂解与燃烧相比 ,燃烧时零价汞被氧化的程度更高。The attention was focused on the mechanism of mercury transport under different coal and reaction conditions. Firstly, the study was beginning with analyzing the mercury content of the residual after coal combustion and pyrolysis under different heating temperatures and heating time. The results indicate that during coal combustion mercury in coal samples discharge faster than during coal pyrolysis. Almost all mercury in coal samples discharged quickly at high temperatures (above 700°C) during coal combustion or pyrolysis. Secondly, the experiments were carried out in a quartz tube furnace. The aim of the work was to study the mechanism of mercury speciation and transport during coal combustion and pyrolysis. The experimental data indicate that the content of divalent mercury (Hg2+) becomes higher, the content of elemental mercury (Hg0) becomes lower at elevated temperatures during coal combustion and pyrolysis. On the other hand, during combustion more elemental mercury (Hg0) is oxidized faster than during coal pyrolysis under the same heating temperature; for different coals, even under the same heating temperature and reaction conditions, the mercury speciation is different.

关 键 词：汞 燃烧 裂解 煤 污染 Hydro方法 烟气 

分 类 号：TQ534[化学工程—煤化学工程]