State Key Lab of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, P. R. China.
College of New Energy, China University of Petroleum (East China), Qingdao 266580, P. R. China.
Environ Sci Technol. 2020 Mar 3;54(5):3022-3031. doi: 10.1021/acs.est.9b06191. Epub 2020 Feb 24.
Sulfuric acid aerosol (SAA) can considerably deteriorate air visibility, which poses a threat to human health. Pretreatment methods that enlarge SAA sizes are crucial to enhanced emission control from industrials. This study provides an insight into SAA growth in terms of aerosol dynamics simulation and growth experiments under simulated flue gas conditions. Results show that SAA growth dynamics are dominated by coagulation and condensation mechanisms for small and large aerosols, respectively. The two mechanisms are coupled mainly in SAA sizes smaller than 0.05 μm. A large amount of time was allotted for the SAA distribution to grow into an approximately log-normal form without the use of any activation methods. Cooling gas and corona discharge can both enhance SAA growth. Cooling gas is in charge of condensation, whereas corona discharge mainly acts on coagulation. They exhibited 14.3% and 12.3% increases in mean diameter and 12.3% and 69.1% decreases in number concentration. In contrast, adding vapor led to a 1.58% decrease in mean diameter and a 9.4% increase in number concentration. Findings suggest that combining cooling gas and corona discharge to simultaneously promote coagulation and condensation and reduce SAA emission from humid flue gas is possible.
硫酸气溶胶（SAA）会显著降低空气能见度，对人类健康构成威胁。增大 SAA 粒径的预处理方法对于工业排放的强化控制至关重要。本研究通过气溶胶动力学模拟和在模拟烟气条件下的生长实验，深入了解 SAA 的生长情况。结果表明，小粒径和大粒径的 SAA 生长动力学分别主要受凝聚和凝结机制控制。这两种机制主要在小于 0.05μm 的 SAA 粒径范围内相互作用。无需任何激活方法，SAA 分布就有大量时间生长成近似对数正态分布。冷却气体和电晕放电都可以增强 SAA 的生长。冷却气体负责凝结，而电晕放电主要作用于凝聚。它们使平均直径分别增加了 14.3%和 12.3%，而数浓度分别降低了 12.3%和 69.1%。相比之下，添加蒸汽会导致平均直径降低 1.58%，数浓度增加 9.4%。研究结果表明，结合冷却气体和电晕放电可以同时促进凝聚和凝结，减少湿烟道气中 SAA 的排放。
