Open AccessREDUCTION OF INHERENT MERCURY EMISSIONS IN PC COMBUSTION
Author(s) -
John C. Kramlich,
Rebecca N Sliger,
David J Going
Publication year - 1999
Language(s) - English
Resource type - Reports
DOI - 10.2172/775019
Subject(s) - mercury (programming language) , limiting , combustion , chemistry , elemental mercury , environmental chemistry , chlorine , homogeneous , char , air pollution , environmental science , computer science , engineering , thermodynamics , organic chemistry , mechanical engineering , physics , programming language , adsorption
Mercury emission compliance presents one of the major potential challenges raised by the 1990 Clean Air Act Amendments. Simple ways of controlling emissions have not been identified. The variability in the field data suggest that inherent mercury emissions may be reduced if the source of this inherent capture can be identified and controlled. The key mechanisms appear to involve the oxidation of mercury to Hg{sup 2}, generally producing the more reactive HgCl{sub 2}, followed by its capture by certain components of the fly ash or char, or in the air pollution control equipment. This research focuses on identifying the rate-limiting steps associated with the oxidation step. Work in this reporting period focused on the refinement of the rate constants used in the kinetic mechanism for mercury oxidation. The possible reactions leading to mercury oxidation are reviewed. Rate constants for these reactions are discussed, using both literature sources and detailed estimates. The resulting mechanism represents the best present picture of the overall chlorine homogeneous oxidation chemistry. Application of this mechanism to the data will be explored in the subsequent reporting period. Work conducted under the present grant has been the subject of two meeting papers presented during the reporting period (Sliger et al., 1998a,b)