Meeting Multiple Challenges: Re-Rating W. A. Parish Unit 8

NOx and Performance Improvements at a 650 MW coal-fired electric generating unit

Derek FurstenwerthManager, Air Resources Division,

Environmental DepartmentReliant Energy

Who Are Reliant Energy and Texas Genco?

• Reliant Energy – Top 10 Generator of Electricity in US– 21,000 megawatts– Operates in 13 states– Also provides support to Texas Genco

• Texas Genco– Former HL&P power plants– 14,400 megawatts total, 12,000 in Houston area– Created as result of Texas Electric Power Industry

Restructuring– Subsidiary of CenterPoint Energy, Reliant to

purchase in 2004

W. A. Parish Station Description

• Located on a 4880 acre site near Thompsons, Tx

• Four gas-fired and four coal-fired steam generators, plus a 13 MW gas turbine generator. Total gross capacity of over 3800 MW (largest fossil plant in U.S.)

• Approximately 360 employees

W. A. Parish Station

W. A. Parish Unit Information

Gas196713GTCoal19826508Coal19805907Coal19786906Coal19776905Gas19685654Gas19612903Gas19581852Gas19581851

Primary FuelYearMWUnit

W. A. Parish Unit 8

• Emission Control Equipment– Baghouse system for particulate control– Low sulfur coal plus flue gas

desulfurization system (FGD) – Low NOx burner/overfire air system– Selective catalytic reduction (SCR)

systems under construction

What are the Challenges Facing W. A. Parish?

• Houston-Galveston SIP– Lowest Coal Unit NOx limits in nation– Cap-and-trade program

• Restructured Texas Electric Market

Why Re-rate?

• Restructured Texas Electric Market– Economics based on production– Production dispatched based on lowest

cost– W. A. Parish is low-cost power plant

• New Opportunities– Improved materials– Better efficiencies

Challenges to Re-rating or“Why doesn’t everyone?”

• New Source Review– BACT– More emission controls– Nonattainment NSR – LAER, offsets

• The Steady Downward March of NOx– NSPS, RACT, SIP Limits– Area-wide NOx reductions – 88% reduction by

2004– More emission controls

» Meeting Multiple Challenges - One stone, two birds

The Steady Downward March of NOx

•WAP 5 – 8 Coal Fired Regulatory NOX

Limits

0.7

0.50.41

0.150.04

00.10.20.30.40.50.60.70.80.9

1

NO

x lb

/MM

Btu

WAP 5-7Permits(1977)

WAP 8Permit(1979)

NOx RACT(1999)

EPA NSPS(1998)

TNRCC SIP(2004)

Regulatory Limits

Current WAP Operating Levels (0.15-0.20)

W A Parish Coal Unit Regulatory NOX Limits

0.5

0.38

0.150.045 0.03

00.10.20.30.40.50.60.70.80.9

1

NO

x lb

/MM

Btu

WAP 8Permit(1979)

NOx RACT(1999)

EPA NSPS(1998)

TCEQ SIP(2004)

WAP SCRDesign

Regulatory Limits

2002 W A Parish NOx Emissions (0.155)

Meeting Multiple Challenges –Re-rating Unit 8

• Increase Production Capacity– 10% Increase – from 590 to 650 MW– Improved efficiency

• New Source Review– No significant increase in NOx, SO2, or VOC due

to emission controls – No NSR or NSPS– PSD for CO, PM10, H2SO4 and Fluoride

• Existing equipment determined to represent BACT

• SIP Compliance– SCR under construction

• Operational by end of 2003• Lowest NOx coal plant in country

W. A. ParishEmission Control Equipment

• Baghouse systems for fly ash removal– Utilize fiberglass bags to

trap fly ash– >99.9% removal efficiency

Unit 5 Baghouse contains ~15,000 bags

W. A. ParishEmission Control Equipment

• Flue Gas desulfurizationsystem (FGD) for SO2 removal on Unit 8

– Spray tower design– Limestone slurry reagent– SO2 removal of ~80%

Unit 8 FGD System

W. A. ParishEmission Control Equipment

• NOx Reduction– Advanced LNB/OFA

systems installed on all coal units

• 1st commercial installation of AlstomLNB/OFA system guaranteed to meet 0.15 lb/MMBtu

• 50%-60% NOx reductions achieved

W. A. ParishEmission Control Equipment

Low NOx design of the Unit 7 & 8 TFS 2000 System

Air injected in theburnout zone

Fuel and air injected in thecombustionzone

P2tm Coal LNB Nozzle Tip

LNB Installation

W. A. ParishEmission Control Equipment

Coal unit SCR'sunder construction– Vanadium-

titanium catalyst– Aqueous NH3

reagent– 80-85% reduction

to meet 0.03 lb/MMBtu

W. A. Parish Unit 8 SCR Retrofit

Fabric Filter

SCR Boiler

FGD

Texas Coal-fired Unit NOx Rates (2001)

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0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

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W. A. Parish Unit 6 SCR Construction (May , 2000)

W. A. Parish Unit 6 SCR Construction (July, 2002)

W. A. Parish Unit 5 SCR Construction (July, 2002)

W.A.Parish Unit 8 SCR Construction (April, 2001)

W. A. Parish Unit 6 Catalyst Loading (July, 2002)

W. A. Parish Unit 6 Catalyst Loading

W. A. Parish Ammonia Tank Farm

W. A. Parish Unit 6 NH3 Injection Nozzles

W. A. Parish Unit 6 NH3 Mixer

Meeting Multiple Challenges –Review

• Increased Production Capacity– 10% Increase – from 590 to 650 MW– Improved efficiency

• Reduced Emissions– SCR under construction

• Cleanest coal plant in country• NOx to 0.03 lb/mmBtu design value

Questions and Answers