130 likes | 144 Views
A software tool for estimating mercury emissions and reductions from coal-fired electric utilities. Allows evaluation of control options and provides detailed reports. Sponsored by US EPA.
E N D
A Software Tool for Estimating Mercury Emissions and Reductions from Coal-Fired Electric Utilities (EU) • Presented at the • NC Clean Smokestacks Act Sections 12 & 13 • Mercury and CO2 Control Options Assessment Workshop • Raleigh, NC April 19, 2004 • Jeffrey D. Cole C. Clark Allen, Ph.D. • colejd@rti.org cca@rti.org • (919) 990-8606 (919) 990-8645
Case-By-Case MACT for New Coal-fired EU Units • 40 CFR Part 63 Subpart B, Title 5. • Tool for evaluating alternatives for mercury control. • Case-by-case MACT is applicable until nationally applicable MACT standard • Tool is not required for a case-by-case analysis. • http://www.epa.gov/ttn/atw/combust/utiltox/utoxpg.html US EPA EU Mercury Software Tool
Software for Electric Utility Mercury Controls • Sponsored by U.S. EPA. • Coal-burning electric utilities. • Predicts the amount of mercury control for conventional electric utility pollution control devices. • Allows the use of site-specific information. • Provides very detailed reports of the results. US EPA EU Mercury Software Tool
Basis of the Model’s Electric Utility Equipment Configurations • 1999 EPA ICR Part III emission test reports (79 separate units, 80 total [1 tested twice]). • Follow up telephone interviews. • Information provided by the EU company. • Company review and feedback. US EPA EU Mercury Software Tool
Fuel Usage and Characterization • Provided by the EU company throughout 1999. • Fuel characterization. • Fuel type (bituminous, subbituminous, lignite..) • Fuel amount combusted for each unit • Fuel characterization, mercury content, other characteristics • Allows the use of site-specific information. US EPA EU Mercury Software Tool
Stack Tests for Electric Utility Mercury Controls • Sponsored by EU companies. • Different types of conventional pollution controls were evaluated. • Measured mercury rates in coal, in gas going into the control unit, and in the gas leaving the control unit. • Formal reports with quality assurance. US EPA EU Mercury Software Tool
Types of Furnaces and Conventional Air Pollution Controls Tested • Conventional furnace, Fluidized-Bed Combustion (FBC), and Integrated Gassification Combined-Cycle (IGCC). • Particulate controls: • Electrostatic Precipitators (both hot-side and cold-side) • Fabric filters • Particulate scrubbers • Mechanical collectors (multiclone). • Sulfur controls: Wet Flue Gas Desulfurization (FGD), Spray Dryer Absorber. • Nitrogen oxide controls: Selective Catalytic Reduction, Selective Non-Catalytic Reduction. US EPA EU Mercury Software Tool
Steps for Using the Software • Select the plant. • Select the unit at the plant. • Examine the existing controls and current estimated mercury air emissions. • Evaluate other control options. • Print reports. US EPA EU Mercury Software Tool
Method for Estimating the Effectiveness of the Mercury Controls, I Bin Method. • Test results are grouped by similar types of units and controls (bins). • Identify the bin that is most similar to the unit of interest. • Apply the bin control efficiency to the 1999 site specific conditions. • Estimate the mercury emission rate for the controls that you have selected. US EPA EU Mercury Software Tool
Method for Estimating the Effectiveness of the Mercury Controls, II Speciation Method. • Evaluate the mercury speciation for the coal type and furnace type: particulate, ionic, and elemental • Evaluate the control effectiveness of each control type for each mercury species. • Apply these factors to the 1999 site-specific conditions. • Sum the remaining mercury species for the controls you have selected to estimate the total mercury emission rate. US EPA EU Mercury Software Tool
Uncertainty Analysis for the Results • Expected mercury air emissions from the analysis. • Range of results due to uncertainty. • Detailed report of the statistics. US EPA EU Mercury Software Tool
Special Features and Options • Select control technology combinations not included in the test program. • Consider site specific factors. • Examine alternative controls (fuel type, furnace equipment combinations). • Automatic warnings. • Automatic site-specific control technology suggestions. • Are other units using the control technology suggestions? US EPA EU Mercury Software Tool
Conclusions • Tool for estimating mercury air emissions only. • Uses an extensive database. • Equipped with detailed reporting utilities. US EPA EU Mercury Software Tool