烟气组分对汞吸附影响的程序升温脱附  

Temperature programmed desorption(TPD)studies on the effect of flue gas component on mercury adsorption

作　　者：陈明明[1] 段钰锋[1] 周强[1] 柳帅[1] 丁卫科 刘猛[1] 

机构地区：[1]东南大学能源热转换及其过程测控教育部重点实验室,江苏南京210096

出　　处：《化工进展》2016年第12期4065-4071,共7页Chemical Industry and Engineering Progress

基　　金：国家重点研发计划(2016YFC020115;2016YFB0600604;2016YFB0600203);国家自然科学基金(51376046;51576044);江苏省环保科研课题(2016030);中央高校基本科研业务费专项资金;江苏省普通高校研究生科研创新计划(CXZZ13_0093;KYLX_0115;KYLX_0184;KYLX15_0071);东南大学优秀博士学位论文培育基金(YBJJ1505)项目

摘　　要：目前燃煤烟气活性炭脱汞技术已经很成熟,但机理方面的相关研究甚少或不全面,为了探讨汞与活性炭在燃煤烟气中的反应路径,本文在固定床上对商业活性炭(FAC)和1%NH4Br改性活性炭(NBAC)进行了汞吸附实验,分别考察了O2、SO_2、CO_2、NO及其混合烟气组分对吸附剂汞吸附的影响,然后利用程序升温脱附(temperature programmed desorption,TPD)技术分析了烟气组分对汞吸附的影响机理。固定床测试结果表明溴化铵改性可显著增加活性炭汞吸附性能,O2、CO_2及NO可促进NBAC对汞的吸附,其中NO最好,而SO_2抑制NBAC对汞的吸附。TPD结果表明,溴素改性促进NBAC表面负载的溴与Hg0结合生成Hg Br2,O2存在促进了Hg0的氧化生成Hg O,NO存在显著增加了Hg2(NO3)2的生成。SO_2与Hg0对活性炭表面的官能团存在竞争吸附的关系,生成C—S,与Hg0反应生成Hg S。CO_2对NBAC吸附Hg0的反应机理影响不大。Removing mercury technology of activated carbon in flue gases is very mature.However, the mechanism of the mercury reaction is seldom.Experiments on mercury capture by a commercial activated carbon and a 1% NH4Br-modified activated carbon were carried out in a fixed-bed reactor under simulated flue gas to study the reaction path among the mercury,flue gas and activated carbon.The effect of single component such as O2,CO_2,SO_2 and NO was investigated.Then the temperature programmed desorption technique was used to identify the mercury species on the adsorption products.The results showed that the bromine impregnation on the activated carbon has a great promotion on the mercury capture.O2 and CO_2 play a positive role in the mercury capture process,while the SO_2 plays a negative function.According to the TPD analysis results,NO promotes mercury capture significantly because of the formation Hg2（NO3）2 on the activated carbon surface.The elemental mercury was oxidized to generate Hg O when O2 was injected.SO_2 competed with Hg0 on the surface functional groups of activated carbon and Hg S was formed because of C—S was formed to react with Hg0.CO_2has little effect on the adsorption mechanism of NBAC.

关 键 词：溴素改性 活性炭 汞 烟气组分 程序开温脱附 

分 类 号：X511[环境科学与工程—环境工程]