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Particulate Matter Seminar
John KushTexas Genco
Rice UniversityShell Center for Sustainability
November 9, 2004
Who is Texas Genco?
• Texas Genco– Formerly HL&P/Reliant Energy power plants– 11 facilities in TX; using natural gas, oil, coal,
lignite and uranium fuels– 14,400 megawatts total, 12,000 in Houston area– Created as result of Texas electric power
industry restructuring– Currently a subsidiary of CenterPoint Energy;
sale to GC Power Acquisition, LLC in progress
W. A. Parish Station
W. A. Parish Unit Information
Unit MW Year Primary Fuel
1 185 1958 Gas
2 185 1958 Gas
3 290 1961 Gas
4 565 1968 Gas
5 690 1977 Coal
6 690 1978 Coal
7 590 1980 Coal
8 650 1982 Coal
GT 13 1967 Gas
W. A. Parish Coal Facts
• Coal Supply and Delivery
– Low sulfur western coal from the Powder River Basin in Wyoming
– Delivery by rail car– Approx. 27,000 tons
burned per day– Approx. 10 million tons
burned per year
Arch Coal, Inc. Black Thunder Mine
W. A. Parish Station
• Emission Control Equipment– Baghouse systems for particulate control– Low sulfur coal (plus flue gas desulfurization
system (FGD) on Unit 8)– Combustion modifications for NOx control on
gas-fired Units 1-4 – Low NOx burner/overfire air systems on Units
5-8– Selective catalytic reduction (SCR) systems
installed on Units 5-8 (planned for Unit 4)
W. A. Parish Emission Control Equipment
• Baghouse systems for fly ash removal– Utilize fiberglass bags to
trap fly ash– >99.9% removal efficiency– Original equipment on Unit
8; retrofit in 1988-89 on Units 5-7 to replace electrostatic precipitators
Unit 5 Baghouse contains ~15,000 bags
W. A. Parish Emission Control Equipment
• Flue Gas desulfurization system (FGD) for SO2 removal on Unit 8
– Spray tower design– Limestone slurry reagent– SO2 removal of ~80%
Unit 8 FGD System
W.A. Parish Coal Combustion Product Management
• Ash Uses– 73% of CCPs are sold
• 90% of all fly ash • 100% of all FGD material• 25% of all bottom ash
– CCPs are utilized as a concrete additive, stabilization and road base/foundation materials
• Ash Disposal– Ash is classified as Class II
non-hazardous waste– Ash disposal in two on-site 30-
acre industrial landfills. Design includes clay liner, cap, and groundwater monitoring
W. A. Parish NOx Control Equipment
Advanced LNB/OFA systems installed on all coal units
• 1st commercial installation of B&W LNBs on Unit 6
• 1st commercial installation of Alstom LNB/OFA system guaranteed to meet 0.15 lb/MMBtu on WAP 7
• 50%-60% NOx reductions achieved
W. A. Parish SCR Construction
W. A. Parish Emission Control Equipment
Coal unit SCR's
– Vanadium-titanium catalyst
– Aqueous NH3 reagent– 80-85% reduction to
meet 0.03 lb/MMBtu– All 4 SCRs operational
by Spring, 2004
W. A. Parish Unit 8 SCR Retrofit
Fabric Filter
SCR Boiler
FGD
The Steady Downward March of NOx Emission Rates
Texas Genco Emission Reduction Results
• W.A. Parish Emission Reductions– Unit 8 SO2 emissions reduced by ~80% (FGD system)– Coal-unit particulate emissions reduced by >99.9%
(Baghouse system)– Coal-unit NOx emissions reduced by ~90% (LNB/OFA
+ SCR systems)
• The Texas Genco system operates with one of the lowest NOx production rates in U.S.
• W. A. Parish coal units are now likely the lowest NOx emitting coal units in the nation.
Questions and Answers