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