New particle formation in the fresh flue-gas plume from a coal-fired power plant: effect of flue-gas cleaning
Atmospheric emissions, including particle number and size distribution, from a 726 MW<sub>th</sub> coal-fired power plant were studied experimentally from a power plant stack and flue-gas plume dispersing in the atmosphere. Experiments were conducted under two different flue-gas clea...
Main Authors: | , , , , , , , , , , , , , , , |
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Format: | Article |
Language: | English |
Published: |
Copernicus Publications
2016-06-01
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Series: | Atmospheric Chemistry and Physics |
Online Access: | https://www.atmos-chem-phys.net/16/7485/2016/acp-16-7485-2016.pdf |
Summary: | Atmospheric emissions, including particle number and size
distribution, from a 726 MW<sub>th</sub> coal-fired power plant were
studied experimentally from a power plant stack and flue-gas plume dispersing
in the atmosphere. Experiments were conducted under two different flue-gas
cleaning conditions. The results were utilized in a plume dispersion and
dilution model taking into account particle formation precursor
(H<sub>2</sub>SO<sub>4</sub> resulted from the oxidation of emitted SO<sub>2</sub>) and
assessment related to nucleation rates. The experiments showed that the
primary emissions of particles and SO<sub>2</sub> were effectively reduced by
flue-gas desulfurization and fabric filters, especially the emissions of
particles smaller than 200 nm in diameter. Primary pollutant concentrations
reached background levels in 200–300 s. However, the atmospheric
measurements indicated that new particles larger than 2.5 nm are formed in
the flue-gas plume, even in the very early phases of atmospheric ageing. The
effective number emission of nucleated particles were several orders of
magnitude higher than the primary particle emission. Modelling studies
indicate that regardless of continuing dilution of the flue gas, nucleation
precursor (H<sub>2</sub>SO<sub>4</sub> from SO<sub>2</sub> oxidation) concentrations remain
relatively constant. In addition, results indicate that flue-gas nucleation
is more efficient than predicted by atmospheric aerosol modelling. In
particular, the observation of the new particle formation with rather low
flue-gas SO<sub>2</sub> concentrations changes the current understanding of the air
quality effects of coal combustion. The results can be used to evaluate
optimal ways to achieve better air quality, particularly in polluted areas
like India and China. |
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ISSN: | 1680-7316 1680-7324 |