煤热解过程中汞析出与汞吸附特性研究  

Experimental Study on Mercury Release and Adsorption during Coal Pyrolysis

作　　者：段钰锋[1] 刘玲[1] 王卉[1] 尹建军[1] 赵长遂[1] 

机构地区：[1]东南大学能源与环境学院,江苏南京210096

出　　处：《太原理工大学学报》2010年第5期619-622,626,共5页Journal of Taiyuan University of Technology

基　　金：国家重点基础研究发展计划(973计划)资助项目(2006CB200304)

摘　　要：采用煤热解释放出汞,并对热解气体进行汞吸附脱除的燃烧前脱汞的技术路线。在程序升温管式炉系统中,实验研究了大同煤和宝日希勒煤,在N2气氛下热解过程中汞析出和汞吸附的特性。热解结果表明:温度是影响煤热解过程中汞释放的主要因素。随热解温度升高,汞释放率急剧上升,在600℃时两种煤中汞释放率达90%以上;被释放的汞蒸气中以元素汞为主。随停留时间的延长和加热速率的升高,煤中汞释放率显著增加;汞析出仍以元素汞为主。考察了四种吸附剂活性炭、飞灰、Ca(OH)2和5%KMnO4改性Ca(OH)2,对大同煤热解气体中汞的吸附特性。结果表明:随热解温度的升高,四种吸附剂的单位汞吸附量均增大;其中活性炭具有较强的汞吸附能力,吸附率达92%以上;飞灰和另外两种钙基吸附剂的汞吸附率在73%～85%之间变化。This paper takes advantage of a new methodology of prior combustion demercurization that removes mercury by adsorbent in coal-pyrolytic gas.Mercury release and speciation during Datong and Baorixile coal pyrolysis and mercury adsorption in coal pyrolysis gases were conducted.Results show that mercury vaporizing from coal pyrolysis depended significantly on temperature.The release rate of Hg increased dramatically with the temperature elevation.More than 90% of mercury in coal was released at 600℃,in which elemental mercury dominated in its gaseous mercury species.Four mercury adsorbents of activated carbon,fly ash,Ca（OH）2 and 5% KMnO4 modified Ca（OH）2 were evaluated in adsorbing mercury in coal pyrolytic gas.Results indicat that mercury adsorption amount increased with pyrolysis temperature,in which the activated carbon was the best with over 92% mercury removal,while the others varied between 73%～85%.The fore-combustion mercury removal technique implies its potential effectiveness for demercurization.

关 键 词：煤热解 汞析出 汞吸附 燃烧前脱汞 

分 类 号：X511[环境科学与工程—环境工程]