Estimating Sulfuric Acid Aerosol Emissions from Coal-Fired Power Plants

Abstract

This paper presents a proposed method for estimating the release of sulfuric acid (H 2SO4) aerosol from coal-fired power plants. The U. S. Environmental Protection Agency’s Toxic Release Inventory (TRI) reporting system requires that, beginning in 1998, electric utilities must estimate their emissions of over 600 chemical compounds. Aerosols of H2SO4 are one of the compounds included in the TRI. In coal-fired plants, H 2SO4 vapor is created in the ductwork downstream of the boiler by the combination of water vapor and sulfur trioxide (SO 3), both of which are produced during the coal combustion process. In some cases, the vapor condenses as an aerosol, which makes it a reportable compound. Since the TRI system does not require the collection of any new data, the method presented herein was developed to use data and information already available at most coal-fired plants. These factors include the SO 2 emission rate, the type of fuel being burned, and the particulate control device used to control dust emissions.