氨法烟气脱硫气溶胶特性试验研究

中文摘要: 气溶胶问题已成为氨法烟气脱硫工艺推广应用的技术瓶颈，本文对氨法脱硫气溶胶化学组分及其粒径进行实时监测，考察了脱硫运行阶段、脱硫液氧化程度及pH值的影响，并试验分析了氨法脱硫过程中气溶胶的形成机理。结果表明，氨法烟气脱硫气溶胶主要为亚微米级颗粒，组分以含硫酸根、铵根为主，集中在0.1？m~0.4？m之间。脱硫初始阶段，气溶胶组分中存在NH4HSO4和NH4HSO3，正常运行阶段，气溶胶组分以(NH4)2SO4和(NH4)2SO3为主。脱硫浆液未进行曝气氧化，气溶胶组分中SO32-为主，充分氧化后，SO42-含量明显增加；提高脱硫浆液pH值，气溶胶组分中SO32-含量增加。非均相反应形成的气溶胶组分中存在NH4HSO4、NH4HSO3；脱硫液滴的夹带和蒸发作用形成的气溶胶成分主要为(NH4)2SO4和少量(NH4)2SO3。非均相反应对于气溶胶的形成占主要贡献，数量浓度与质量浓度均高于单纯夹带蒸发。
Abstract:Aerosol emission has been the bottleneck problem for the development of ammonia flue gas desulfurization. In this paper, aerosol properties were investigated on-line. Experiments on the effect of different desulfurization phases, oxidation degree and pH value of desulfurization liquid and the analysis of the aerosol formation were carried out. As the results show, aerosols are mainly submicron particles ranging from 0.1μm to 0.4μm. NH4HSO4 and NH4HSO3 exist during the initial phase of desulfurization, while (NH4)2SO4 and (NH4)2SO3 are the main part when the system is in good running. Without oxidation of desulfurization liquid, the aerosol compositions are mainly SO32- and the amount of SO42- increases significantly after oxidation. The amount of SO32- increases when the pH value of desulfurization liquid gets higher. NH4HSO4 and NH4HSO3 exist in the aerosols formed by the heterogeneous reaction which makes greater contribution to the aerosol formation and the compositions of aerosols formed by entrainment and evaporation of desulfurization