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Fast Evolution of Sulfuric Acid Aerosol Activated by External Fields for Enhanced Emission Control
journal contribution
posted on 2020-02-24, 17:39 authored by Zhengda Yang, Chenghang Zheng, Qingyi Li, Hao Zheng, Haitao Zhao, Xiang GaoSulfuric 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.