DOE-NETL’s Mercury R&D Programs for Coal-Fired Power Plants
Third Annual West Virginia Water Conference
October 28-29, 2004 Roanoke, WV
Lynn A. Brickett
National Energy Technology Laboratory
Innovations for Existing Plants
Program Components
Goal
Enhance environmental performance of existing fleet of coal power plants and advanced power systems
R&D Activities
Mercury control NOx control Particulate matter control Air quality research Coal utilization by-products Water management
TJ Feeley June 2004
Preview
Hg concentrations EPA data collection Hg regulations
NETL-sponsored research
Hg & by-product connection
Global Mercury Emissions
Emissions from Natural Sources (Volcanoes, Forest Fires, etc.) U.S. Coal-Fired Power Plants Re-Emission of Prior Anthropogenic Emissions New Anthropogenic Emissions*
1540 tons
48 tons
440 tons
2820 tons
*Note: Does not include U.S. Coal-Fired Power Plant Emissions
FACT: It is estimated that U.S. coal-fired power plants emit approximately 1% of annual global mercury emissions
Source: UNEP Global Mercury Assessment, December 2002
Estimated U.S. Anthropogenic Mercury Emissions in 1999
Source: Personal communication with U.S. EPA 7/16/03 1999 NEI Version 3.0
Information Collection Request (ICR)
EPA initiated Three phases 1. Plant info 2. Specific coal data
1. 2.
Coal type Chlorine conc.
3. 80 site specific samples
1.
Multiple pollution control devices
U.S. Coal-Fired Power Plant Hg Emissions (ICR)
Tons Hg/Yr
Average Coal Chloride Content by Coal Rank
1200
1000
Coal Chloride Content, ppm
800
Mean
600
Median
400
200
0
Bituminous
Subbituminous
Lignite
Source: EPA 1999 ICR Data
Hg Speciation
Three forms in flue gas Oxidized or Reactive Gaseous Hg (RGM)- water soluble Particulate – condensable on soot or ash Elemental – difficult to control Speciation predicts possible control
technologies
Average Mercury Speciation in Coal-Fired Power Plant Flue Gas
Elemental 54%
Particulate 3%
Oxidized 43%
Source: EPA 1999 ICR Data
Mercury Regulation or Legislation?
Regulation: EPA proposal issued 12/15/03 Several alternatives for control offered for comment Maximum Achievable Control Technology (MACT) Plant-by-plant – no trading Approx. 29% reduction by 2007/08 Cap & Trade FGD/SCR co-benefit (29% reduction) by 2010 15 ton cap (69% reduction) by 2018 Legislation: Clear Skies Act of 2003 Cap & trade 34 ton cap (29% reduction) by 2010 15 ton cap (69% reduction) by 2018
President Bush Announcing Clear Skies Initiative February 14, 2002
TJ Feeley June 2004
Over a Decade of DOE/NETL Hg R&D
1990 1995
Emission characterization/ methods development Lab/bench-scale R&D Emissions Characterization Methods/CEM development Bench- and pilot-scale R&D CEM development Emissions characterization Byproducts characterization Field testing CEM development Plume chemistry Byproducts characterization Field testing Commercial demos -1990 Clean Air Act Amendments and HAP Reports To Congress
- Hg
2000
2005
2010
Regulatory Determination
-Hg
-Proposed
Hg Regulations
Over $52.5 million spent on mercury R&D over the past seven years!
Hotspots?
Issues with Cap & Trade Mercury becomes “concentrated”
in certain areas near sources Secretary McGinty (PA-DEP)
“Unlike most pollutants, Hg is highly toxic and does not disperse easily, creating “hot spots” of contamination.” July 04 “Specifically, we are concerned that local “hot spots” of elevated mercury may result or worsen, especially if the required reduction levels are not sufficiently strict” Feb 04
Secretary Cipriano (IL-EPA)
Bowen Results
EPRI & EERC & TVA
RGM/NOx vs Downwind Distance for Four Full Experimental Flights by TVA at Plant Bowen - Typical Stack Ratio by OH Method Indicated by Triangle
30 25 20 15 10 5 0 0 5 10 Distance downwind (km)
RGM/NOx
y = -0.7638x + 24.049 R2 = 0.6409
15
Pleasant Prairie Results
EPRI & EERC & TVA
DOE/NETL Funded Approaches for Controlling Mercury
Combustion/ Chemistry Modification
Sorbent Injection Scrubber Polishing Enhancement/ Technology Oxidation
Coal Boiler
•Coal cleaning •Cl-based additives •Combustion modifications
Baghouse or ESP
•ACI •Amended silicates •Halogenated AC •Ca-based sorbents •Chemically treated sorbents •COHPAC/Toxecon™ •Thief sorbents
Scrubber
•Oxidation catalysts •Reagent addition •Ultraviolet radiation (GP-254) •Electrocatalytic oxidation •SCR oxidation •MerCAP™ •ECO/Wet ESP
TJ Feeley June 2004
ADA-ES Phase I Results 2001-02
Activated Carbon Injection
100
Gaston: Bituminous coal, ESP + fabric filter Salem Harbor: Bituminous coal, ESP (gas temp. at 280-290 °F) Pleasant Prairie: Subbituminous coal, ESP Brayton Point: Bituminous coal, ESP
Mercury Removal (%)
80 60 40 20 0 0 5 10 15 20 25 30
Injection Concentration (lb / MMacf)
Gaston, Pleasant Prairie, and Brayton Point test data from ADA-ES presentation at August 2002 EPA Utility MACT Working Group meeting. Salem Harbor test data from ADA-ES technical paper “Results of Activated Carbon Injection Upstream of ESP for Mercury Control” presented at May 2003 Mega Symposium.
Mercury Control Using ACI Preliminary Cost Estimate
Activated Carbon Injection System for 500 MW Bituminous Coal-Fired Plant* Mercury Removal,% Levelized Cost Mills/kWh $/lb mercury removed** Mills/kWh $/lb mercury removed**
*Plant equipped with cold-side ESP **Incremental cost excluding co-benefit ESP mercury capture (36%) ***Penalty includes lost sales revenue ($18/ton) and ash disposal cost ($17/ton). Note: mills equal to one tenth of a cent.
TJ Feeley June 2004
70%
90% w/ COHPAC
Without lost ash sales penalty 1.27 46,100 3.69 133,800 2.15 49,000 2.15 49,000
With lost ash sales penalty***
EPRI TOXECON™ Configuration
TOXECON™
Sorbent Injection PJFF
Coal Electrostatic Precipitator
N
Fly Ash (99%)
Fly Ash (1%) + PAC
TJ Feeley June 2004
Observations From Phase I Field Tests
Hg capture performance
ACI works, however… Effectiveness of ACI depends on coal type and plant configuration Wet scrubber process design and chemistry may affect re-emission
Uncertainties remain
Performance over longer periods of operation Capture effectiveness with low-rank coals Sorbent feed rate and costs FGD Hg reduction/re-emission By-product use and disposal Need for fabric filter for units equipped with ESP Balance-of-plant impacts
TJ Feeley June 2004
Mercury Pilot-Scale Testing
Projects Conducted in 2001-03
Apogee Scientific Powerspan
Advanced novel sorbent testing
CONSOL
Multi-pollutant control using electro-catalytic oxidation (ECO)
URS Group
Evaluate effect of lowering flue gas temperature on Hg capture with ESP
UNDEERC
Evaluate fixed-bed oxidation catalysts
Southern Research Institute
Sorbent injection testing with Advanced Hybrid Particulate Collector (AHPC)
Evaluate calcium-based sorbents, oxidation additives, and coal blending
Designed to Achieve 90% Hg Removal
Additional Field- and Pilot-Scale Testing
Projects Initiated in 2003
General Electric Energy and Environmental Research
Corp Evaluate OFA and coal reburn to optimize mercury removal with an ESP at Western Kentucky Energy’s Green Power Station
CONSOL
Mercury speciation field testing at several plants equipped with both SCR and wet FGD
Reaction Engineering
Pilot-scale mercury oxidation test for several NOx SCR catalysts at AEP’s Rockport Power Plant which burns PRB coal
DOE/NETL Phase II, Round 1 Mercury Field Testing Program 2004-05
Hg Control Approach
Activated carbon injection (ACI)
Amended silicates Oxidation catalyst Chemical inject. w/ ACI, chemically modified ACI Chlorine injection Fixed structure gold sorbent Halogenated ACI
Host Sites
5
1 2 4 2 2 2
Coal Types
PRB, Bit., PRB/Bit. blend
Bituminous TX lignite, bituminous ND lignite ND lignite, TX lignite ND lignite, bituminous Bit., bit/PRB blend
Downstream Control Equipment
FF, ESP, ESP w/ NH3/SO3 injection
ESP ESP, ESP/wet FGD ESP, FF/SDA ESP/wet FGD FF/SDA, ESP/wet FGD HSESP, ESP
TJ Feeley June 2004
Long-Term Continuous B-PAC Run at St. Clair
CUB Production and Utilization for 2002
FGD Material 23% FBC Ash 1%
Production 129 million tons
Boiler Slag 1%
Waste Stabilization 8%
Other 9%
Cement / Concrete 35%
Bottom Ash 15%
Fly Ash 60%
Wallboard 16% Mining 8% Construction 24%
Utilization (35%) 45 million tons
Data per ACAA 2002 CUB Survey
DOE/NETL’s Coal Utilization By-Products Research Program
Goal is to increase CUB beneficial use to 50% by 2010 Working with key stakeholders such as 50%
American Coal Ash Association, EPRI, and EPA to evaluate:
40% 30% 20%
Leaching of Hg & other elements Volatilization of Hg Microbial mobilization of Hg
10% 0% 1985
Actual
(Source: ACAA)
1990 1995
2000 2005
2010
Research includes products from advanced coal gasification
and FBC technologies
TJ Feeley June 2004
Challenges to Increased CUB Utilization
Future air pollution regulations,
e.g., Clear Skies, Mercury MACT Increase volume of coal utilization by-products Change characteristics (i.e., quality) of by-products
Mercury
Future solid waste
Fly Ash
FGD Byproduct
regulations under RCRA? Limit use applications Regulate coal utilization byproducts as hazardous Public perception
Hazardous Waste Designation of All By-products Could Cost $11 Billion / Year
DOE/NETL Environmental and Water Resources (Innovations for Existing Plants Program)
To find out more about DOE-NETL’s Hg and CUB R&D activities visit us at: www.netl.doe.gov/coalpower/environment
TJ Feeley June 2004