REDUCTION OF INHERENT MERCURY EMISSIONS IN PC COMBUSTION
Oxidized mercury has been shown to be more easily removed from power plant flue gas by existing air pollution control equipment (e.g., wet scrubbers) than elemental mercury. The factors that determine how mercury is converted to the oxidized form in practical systems are, however, unknown. The present research focuses on developing an elementary, homogeneous mechanism that describes the oxidation of mercury by chlorine species as it occurs in practical furnaces. The goal is to use this mechanism (1) as a component in an overall homogeneous/heterogeneous mechanism that describes mercury behavior, and (2) to suggest low cost/low impact means of promoting mercury oxidation in furnaces. The results suggest an important role for Hg+Cl {r_arrow} HgCl and HgCl + Cl {r_arrow} HgCl{sub 2}. Here, the Cl is derived by radical attack on HCl in the high-temperature environment. The results suggest that the oxidation occurs during the time that the gases cool to room temperature. The high Cl concentrations from the flame persist into the quench region and provide for the oxidation of Hg to HgCl{sub 2} under lower temperatures where the products are stable. Under this mechanism, no significant HgCl{sub 2} is actually present at the higher temperatures where oxidized mercury is often reported in the literature (e.g., 900 C). Instead, all oxidation occurs as these gases are quenched. The results suggest that means of promoting Cl concentrations in the furnace will increase oxidation.
- Research Organization:
- Federal Energy Technology Center Morgantown (FETC-MGN), Morgantown, WV (United States); Federal Energy Technology Center Pittsburgh (FETC-PGH), Pittsburgh, PA (United States)
- Sponsoring Organization:
- US Department of Energy (US)
- DOE Contract Number:
- FG22-95PC95216
- OSTI ID:
- 780795
- Report Number(s):
- DE-FG22-95PC95216-09; TRN: AH200121%%119
- Resource Relation:
- Other Information: PBD: 26 Aug 2000
- Country of Publication:
- United States
- Language:
- English
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REDUCTION OF INHERENT MERCURY EMISSIONS IN PC COMBUSTION
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