湿法脱硫烟气中细颗粒物的变化特性  

Impact property on fine particles from coal combustion in wet flue gas desulfurization process

作　　者：颜金培[1] 杨林军[1] 鲍静静[1] 

机构地区：[1]东南大学能源与环境学院,南京210096

出　　处：《东南大学学报（自然科学版）》2011年第2期387-392,共6页Journal of Southeast University：Natural Science Edition

基　　金：国家高技术研究发展计划(863计划)资助项目(2008AA05Z306);江苏省科技计划项目基础研究计划资助项目(SBK20082325)

摘　　要：采用ELPI(电称低压冲击器)对WFGD(湿法烟气脱硫)前后烟气中的细颗粒进行采样分析,获得细颗粒浓度与粒径分布特性.对脱硫前后细颗粒形貌和主要元素进行SEM(扫描电镜)和EDS(能量色谱仪)分析.结果表明,NaOH和CaCO3脱硫后,WFGD系统对细颗粒脱除效率很低;氨法脱硫后WFGD出口颗粒数浓度明显增加;脱硫前后,细颗粒的形貌特征和元素组分会发生很大变化,洗涤前燃煤细颗粒表面容易吸附小颗粒而形成表面粗糙的团聚体结构;CaCO3脱硫后,细颗粒容易被脱硫反应产物连结或包裹而形成致密的不规则块状或团聚结构;氨法脱硫后,细颗粒多呈立方体或棱柱体等规则的晶体结构.脱硫前和用水洗涤后,烟气中的细颗粒主要元素为O,Al和Si;脱硫后颗粒中S元素的含量均明显增大,如采用NaOH,CaCO3和氨水脱硫后,颗粒中硫元素含量由洗涤前的1.33%分别增大到了10.01%1,9.96%和46.64%.Fine particles in flue gas before and after WFGD（wet flue gas desulfurization） were sampled and measured by ELPI（electrical low pressure impactor）.Fine particle concentrations and size distributions characteristics were obtained.And the microstructure and major element concentrations of particles were analyzed by SEM（scanning electron microscopy） and EDS（energy disperse spectroscopy）,respectively.The results show that the removal efficiency of fine particles by WFGD is extremely low using NaOH and CaCO3 desulfurization,but particle number concentration has an obvious increase after ammonia desulfurization.Particles morphology structure and element contents have a great change after WFGD.The surfaces of fine particles from coal-fired may adsorb small particles to form roughness and aggregate structure.But it can be enwrapped by desulfurization reaction products to form a dense irregular block-like structure after CaCO3 desulfurization process.And fine particles are mostly of cube or prism crystal structure after ammonia desulfurization.The main elements of fine particles before WFGD are O,Al and Si,however,the element content of S in particles is significantly increased after desulfurization,which increases from 1.33% to 10.01%,19.96% and 46.64% after NaOH,CaCO3 and NH3 desulfurization respectively.

关 键 词：湿法烟气脱硫 细颗粒 粒径分布 洗涤 

分 类 号：X511[环境科学与工程—环境工程]