不同电场飞灰对汞的吸附特性及富集规律研究  

Study on mercury adsorption features and enrichment law of fly ash with different electric fields

作　　者：顾永正[1] 张永生[1] 张振森[1] 徐鸿[1] 潘伟平[1,2] 

机构地区：[1]华北电力大学能源环境科学与工程研究所,北京102206 [2]西肯塔基大学燃烧科学与环境技术研究所,美国肯塔基42101

出　　处：《煤炭科学技术》2016年第3期163-168,共6页Coal Science and Technology

基　　金：国家高技术研究发展计划(863计划)资助项目(2013AA065404);中央高校基本科研业务费专项资金资助项目(13ZD04);高等学校学科创新引智计划资助项目(B12034)

摘　　要：为了实现廉价飞灰基汞吸附剂的开发,分析了某燃煤电厂静电除尘器不同电场飞灰汞含量,并在固定床上开展了汞吸附性能评价试验。结果表明:不同电场飞灰对汞富集能力先增加再减小,富集过程更可能是以氧化态汞的形式富集在飞灰表面。电场1的飞灰中未燃尽碳含量高,与汞的接触机会多,表现出较强的汞吸附能力;其他电场飞灰汞吸附性能和物化特性未呈线性关系,吸附过程受多个因素影响。Lagergren准一级动力学模型更适合预测电场飞灰汞吸附过程,颗粒外气膜扩散影响较大。另外,通过平衡吸附量占有率考察飞灰在烟道中对汞的富集及其进一步脱汞的潜力,得到电场1的飞灰最适合作为吸附剂脱除烟气中的汞。In order to realize the development of a low cost fly ash based mercury adsorbent,the paper analyzed the mercury contents of the fly ash with different electric fields in an electrostatic precipitator of a coal-fired power plant and an evaluation experiment of the mercury adsorption performances was conducted on the fixed bed. The results showed that the mercury enrichment capacity of the fly ash with different electric fields would be firstly increased and then reduced and during the enrichment process,the mercury would possibly be enriched on the surface of the fly ash with an oxidation state mercury mode. The content of the not combusted carbon in the fly ash of No.1 electric field was high,and the fly ash would have many contact chances with mercury and would show a high adsorption capacity of mercury. The mercury adsorption performances and physicochemical features of the fly ash in other electric fields would not be in a linear relationship and the adsorption process would be affected by several factors. Lagergren pseudo-first order dynamics model would be more suitable to predict the mercury adsorption process of the fly ash in the electric field and the external gas film diffuse influence of the fly ash particles were high. In addition,an occupied rate of the balanced adsorption volume was applied to investigate the mercury enrichment and the further mercury removal potential of the fly ash in the flue. And the fly ash obtained in No.1 electric field would be the most suitable to be adsorbent to remove mercury from flue gas.

关 键 词：燃煤飞灰 电场 汞富集 吸附能力 

分 类 号：TQ534.9[化学工程—煤化学工程]