烟气联合脱硫脱硝过程中活性焦表面化学的变化及影响  

Evolution and effects of surface chemistry of activated coke during combined SO_2/NO_xremoval process

作　　者：解炜[1,2] 梁大明[2] 孙仲超[2] 李兰廷[2] 王永刚[1] 徐振刚[2] 

机构地区：[1]中国矿业大学化学与环境工程学院,北京100083 [2]煤炭科学研究总院北京煤化工研究分院,北京100013

出　　处：《中国矿业大学学报》2011年第3期448-452,463,共6页Journal of China University of Mining & Technology

基　　金：国家重点基础研究发展计划(973)项目(2006CB200302);国家高技术研究发展计划(863)项目(2008AA05Z301)

摘　　要：了解活性焦表面性质在烟气联合脱硫脱硝过程中的演变是解析活性焦联合脱硫脱硝机制的一个途径.在自制的微型反应器中模拟烟气活性焦联合脱硫脱硝过程,考察烟气中残余SO2对活性焦选择性催化还原(SCR)脱除NO的影响、以及脱硝后活性焦对SO2脱除效率的影响.利用X光电子能谱(XPS)、扫描电镜(SEM)等表征联合脱硫脱硝过程中活性焦表面化学性质及形貌的变化.结果表明,在脱硝过程中烟气里残余的SO2对吸附态NH3的消耗是造成NO转化率降低的主要原因;经过脱硝的活性焦,由于表面酸性因表面氧含量降低而降低、芳香族π离域碳含量的增加和含氮官能团的引入增加了表面的碱性,提高了活性焦脱硫效率.The evolution of surface chemistry of activated coke during combined SO2/NOx removal process can be used to elucidate the mechanism of flue gas purification process.The experiments on combined desulfurization/denitration of the flue gas were conducted in a micro reactor.The effect of trace SO2 left in the flue gas after desulfurization on removal of NO by the selective catalytic reduction（SCR）,as well as the influence of denitration on followed desulfurization were investigated.The X-ray photoelectron spectroscopy（XPS） and the scanning electron microscope（SEM） were used to characterize the surface properties and morphology of activated coke before and after desulfurization/denitration.The results show that the depleting adsorbed NH3 consumed by reaction with SO2 is the main reason for decreasing NO conversion.The desulfurization efficiency of activated coke are strengthened because of the decreasing acidic surface functional groups resulting from the decrease of oxygen content,delocalization of the π-electron of carbon,and the introduction of N-containing compounds onto the surface of activated coke resulting in the enhancement of basic surface functional groups.

关 键 词：活性焦 脱硫 脱硝 烟气 表面性质 

分 类 号：X701.3[环境科学与工程—环境工程]