FGD, SCR, & Other Retrofit NOx ControlsFGD, SCR, & Other

Retrofit NOx Controls

Presented by:

Joe Ennis, Director

Project Engineering

APP Site Visit

October 30 – November 4, 2006

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FGD Retrofit Program

• Current Program includes 10 Units Totaling 8400 MWs • Construction Timeline is late 2006 through 2010• FGD Limestone Based Technologies include Spray

Tower, Spray/Tray Tower and Jet Bubbling Reactor• Key Design Parameters and Project Goals

– 98% SO2 Removal with 99% Reliability– Fuel Flexibility Sulfur Content Ranges from 2.7% to 4.5%– Disposal and Wallboard Quality Gypsum (site dependent)– Alloy 2205 and 255 Absorber Construction; FRP Internals with

Jet Bubbling Reactor– Less than 10 ppm SO3 at Stack Outlet– Convert to Balanced Draft Steam Generator Operation– Limestone Quality from 88 to 95% Calcium Carbonate

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FGD Retrofit Program

• Additional Design and Equipment Parameters– Single Absorber Module up to 800 MW– SO3 Absorber Capture 30 to 40%– Wastewater Treatment System for Chloride Purge Stream

Treatment– Redundant Ball Mills, Spare Vacuum Filters and Recycle Pumps– Saturated Exit gas at 130F – 900ft+ Tall FRP Lined Stacks– Axial Flow ID Fans Up to 19,000 HP– Dry Sorbent Injection for SO3 Control Upstream of Precipitators– 8+ miles of Conveying Systems to Handle 360 tph limestone and

540 tph gypsum

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Typical Spray/Tray Tower Module

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Typical Jet Bubbling Reactor Flow

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Typical Jet Bubbling Reactor Detail

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SCR Retrofit Program

• Current Program includes 3 Units Totaling 2380 MWs • Construction Timeline is late 2006 through 2009• Key Design Parameters

– 90% NOx Removal Over the Unit Load Range– Inlet NOx Concentration 0.60 lb per 10^6 BTU – 99+ % Reliability– No Reactor Bypass– Static Ammonia Mixers– On Site Ammonia Production– Less 2 ppm Ammonia Slip at 16,000 Service Hours– SO2 to SO3 Conversion of 0.65%

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Typical Static Mixing SCR

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FGD, SCR and Other Retrofit NOx Controls

QUESTIONS????