湿式氨法烟气脱硫中气溶胶的形成特性研究  

Formation Characteristics of Aerosols in Wet Ammonia-Based Desulphurization Process

作　　者：鲍静静[1] 印华斌[2] 杨林军[1] 颜金培[1] 

机构地区：[1]东南大学环境科学与工程系,江苏南京210096 [2]河海大学环境科学与工程学院,江苏南京210098

出　　处：《高校化学工程学报》2010年第2期325-330,共6页Journal of Chemical Engineering of Chinese Universities

基　　金：国家自然科学基金资助项目(20576020);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：气溶胶的形成是湿式氨法烟气脱硫过程存在的主要问题,通过测试分析氨法脱硫前后细颗粒的浓度与粒径分布、颗粒形态及其组成的变化特性,探讨了氨法脱硫中气溶胶的形成机理,并考察了影响气溶胶颗粒形成的主要因素。结果表明:氨水挥发逸出的气态NH3与烟气中SO2发生气相反应是气溶胶形成的主要原因,气溶胶含(NH4)2SO4、(NH4)2SO3、NH4HSO3等组分,粒径集中在0.07～0.70μm范围内,氨法脱硫系统对其难以有效脱除;氨水脱硫液温度及其浓度、烟气中SO2浓度、液气比等对气溶胶形成具有重要影响,形成量随氨水脱硫液及烟气中SO2浓度升高而增多,在保持NH3:SO2化学计量比不变的情况下,随液气比增大,气溶胶颗粒形成量减少。最后,对气溶胶颗粒的控制措施提出了建议。Aerosol formation is the primary problem of the wet ammonia-based desulphurization process. Experiments for the research of the aerosol formation characteristics were carry out on a coal-fired boiler with wet ammonia-based desulphurization devices. The particle size distributions and number concentrations, morphologies and element compositions before and after desulphurization of the aerosols were measured. The mechanism and influencing factors of aerosol formation were analyzed, and the results show that the aerosols, which may include （NH4）2SO4, （NH4）SO3, NH4HSO3 and so on, are formed mainly by the gas-phase reaction between NH3 and SO2. The aerosol particles formed are mostly with the size range of 0.07～0.70 μm, and can not be removed by the conventional ammonia-based desulphurization systems. It was also found that the temperature and concentration of ammonia solution, SO2 content in flue gas and liquid-gas ratio have significant influence on aerosols formation, and more aerosols will be formed with the increase of SO2 content in the flue gas and the increase of NH3 concentration in the scrubbing liquid. Under a certain ratio of NH3：SO2, the formation of aerosol particles decreases with the increase of liquid-gas ratio. Moreover, some suggestions about how to control the formation of the aerosol particles were proposed.

关 键 词：湿式烟气脱硫 氨法 气溶胶 细颗粒 

分 类 号：X511[环境科学与工程—环境工程] O648.18[理学—物理化学]