Title

Investigation of Aerosol and Gas Emissions from a Coal-Fired Power Plant under Various Operating Conditions

Abstract

The concentrations of fine particles and selected gas pollutants in the flue gas entering the stack were measured under several common operation modes in an operating coal power plant producing electricity. Particle size distributions in a diameter range from 10 nm to 20 μm were measured by a scanning mobility particle sizer (SMPS), and the flue gas temperature and concentrations of CO2 and SO2 were monitored by a continuous emission monitoring system (CEMS). During the test campaign, five plant operating modes were studied: soot blowing, bypass of flue-gas desulfurization (FGD), reheat burner operating at 0% (turned off), 27%, and 42% (normal condition) of its full capacity. For wet and dry aerosols, the measured mode sizes were both around 40 nm, but remarkable differences were observed in the number concentrations (#/cm3, count per square centimeter). A prototype photoionizer enhanced electrostatic precipitator (ESP) showed improved removal efficiency of wet particles at voltages above +11.0 kV. Soot blowing and FGD bypass both increased the total particle number concentration in the flue gas. The temperature was slightly increased by the FGD bypass mode and varied significantly as the rating of reheat burner changed. The variations of CO2 and SO2 emissions showed correlations with the trend of total particle number concentration possibly due to the transitions between gas and particle phases. The results are useful in developing coal-fired power plant operation strategies to control fine particle emissions and developing amine-based CO2 capture technologies without operating and environmental concerns associated with volatile amine emissions.

Implications: The measurement of the fine particle size distributions in the exhaust gas under several common operating conditions of a coal-fired power plant revealed different response relations between aerosol number concentration and the operating condition. A photo-ionizer enhanced ESP was demonstrated to capture fine particles with higher efficiency compared to conventional ESPs, and the removal efficiency increased with the applied voltage. The characteristic information of aerosols and main gaseous pollutants in the exhaust gas is extremely important for developing and deploying CO2 scrubbers, whose amine emissions and operating effectiveness depends greatly on the upstream concentrations of fine particles, SO2, from the power plant.

Department(s)

Civil, Architectural and Environmental Engineering

Comments

This work was partially supported by a grant from the U.S. National Science Foundation (NSF CBET-1705864) and by the U.S. Department of Energy/National Energy Technology Laboratory through a Cooperative Agreement (DE-FE0026588).

Keywords and Phrases

Aerosols; Carbon dioxide; Coal; Coal fueled furnaces; Efficiency; Electrostatic precipitators; Environmental technology; Flue gases; Flues; Fog; Gas emissions; Image enhancement; Mining; Particle size; Precipitation (chemical); River pollution; Shape memory effect; Size distribution; Soot; Coal-fired power plant; Continuous emission monitoring system; Electrostatic precipitators (ESP); Environmental concerns; Flue gas desulfurization(FGD); Flue gas temperatures; Particle number concentration; Scanning mobility particle sizer; Fossil fuel power plants

International Standard Serial Number (ISSN)

1096-2247

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2019 A&WMA, All rights reserved.

Publication Date

01 Jan 2019

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