Modeling arsenic partitioning in coal-fired power plants

Journal Article · Wed Nov 15 04:00:00 EST 2006 · Combustion and Flame

DOI:https://doi.org/10.1016/J.COMBUSTFLAME.2006.08.005· OSTI ID:20824171

Senior, Constance L; Lignell, David O; Sarofim, Adel F ^[1]; Mehta, Arun ^[2]

---

1. Reaction Engineering International, 77 West 200 South, Suite 210, Salt Lake City, UT 84101 (United States)
2. EPRI, 3412 Hillview Avenue, Palo Alto, CA 94303 (United States)

Vapor-phase arsenic in coal combustion flue gas causes deactivation of the catalysts used in selective catalytic reduction (SCR) systems for NO{sub x} control. A one-dimensional model has been developed to predict the behavior of arsenic in the postcombustion region of a coal-fired boiler as a function of gas residence time. The purpose of the model is to calculate the partitioning of arsenic between the vapor phase from volatilization and arsenic on the ash particles due to surface reaction and/or condensation at temperatures characteristic of SCR systems. The model accounts for heterogeneous condensation of arsenic on the fly ash, as well as surface reaction for two regimes: (1) the free molecular regime (submicrometer ash particles) and (2) the continuum regime (supermicrometer ash particles). All gas properties are computed as functions of gas temperature, pressure, and composition, which are allowed to vary. The arsenic model can be used to calculate the impact of coal composition on vapor-phase arsenic at SCR inlet temperatures, which will help utilities better manage coal quality and increase catalyst lifetimes on units operating with SCR. The arsenic model has been developed and implemented and was tested against experimental data for several coals. (author)

• OSTI ID: 20824171
• Journal Information: Combustion and Flame, Journal Name: Combustion and Flame Journal Issue: 3 Vol. 147; ISSN CBFMAO; ISSN 0010-2180
• Country of Publication: United States
• Language: English

Related Subjects

20 FOSSIL-FUELED POWER PLANTS
AIR POLLUTION CONTROL
ARSENIC
CHEMICAL COMPOSITION
COAL
COMBUSTION
DISTRIBUTION
FLUE GAS
FLY ASH
FOSSIL-FUEL POWER PLANTS
MATHEMATICAL MODELS
NITROGEN OXIDES
ONE-DIMENSIONAL CALCULATIONS
PRESSURE DEPENDENCE
SELECTIVE CATALYTIC REDUCTION
TEMPERATURE DEPENDENCE
TIME DEPENDENCE