an igcc design improvement case study

TECO to Today: An IGCC Design Improvement Case Study

Dr. Klaus PayrhuberEnergy Applications & Systems EngineeringGE Energy Europe

Kent Dawson60Hz IGCC Product ManagerGE EnergyHouston, Texas

2 /Coal-Gen 2008

Copyright 2009 General Electric Company. All Rights Reserved. This material may not be copiedor distributed in whole or in part, without prior written permission of the copyright owner.

Tampa Electric Co. 1996-Present• Feedstock: Coal, Pet Coke, Biomass

• GE Gasifier/RSC

• 250 MW net IGCC output

• GE 7FA Gas Turbine

• GE Steam Turbine

13 years of operation84,000 operating hours

High availabilityLower emissionsLow cost electricity

Courtesy: Tampa Electric Company

3 /Coal-Gen 2008


AERIAL PHOTO

ControlRoom

Air Separation Unit (ASU)

Gasifier/RSC Coal Silos

Slurry Preparation

Sulfuric Acid Plant

HRSG

Combustion turbineSteam turbine

, Courtesy: Tampa Electric Company

4 /Coal-Gen 2008


TEC Process Flow Diagram

• Slurry Preparation

• Gasification/ High-temp. gas cooling (HTGC)

• Solids/Water handling

Main AirCompressor

32 MW

Dryers

Coal &Pet Coke2300 TPD

Rod Mills

Water &Recycled Char

SlurryTanks

SlurryPump

ProductCompressors

18 MW

Oxygen2100 TPD

ColdBox

LockhopperChar &

Slag

Char & Cl

Compressor Turbine

Combustor

Generator192 MW

CleanStackGas Air

Condenser

CondensatePump

1600 psigSaturated

Steam

7000 KSCFHClean Syngas

Diluent Nitrogen5250 TPD

RadiantSyngasCooler

Gasifier

SyngasCooler

Final Filter

CoolingWater

MDEA Acid Gas RemovalAcid GasH2S + CO2

CoolingWater

55 psigSteam

EconomizedBoiler

Feedwater

BFW Pump

Heat RecoverySteam Generator

(HRSG)

Generator123 MW

Steam Turbine

Raw Syngas

COSHydrolysis

(COS H2S)

Convective

CombustionTurbine

Saturator

WaterScrubbers

400psigSteam

450 gpmSlurry

Backup/StartupDistillate Fuel

To SulfuricAcid Plant

LPSteam

BFW

2 independent trains

5 /Coal-Gen 2008


Slurry Preparation Subsystem

Coal Slurry toGasif ier

Rod Mill

MillDischargeTank

RecycledFines

GreyWater

Agitator

Coalfrom

Storage

Slurry Run Tank

Agitator

CoarseTrommelScreen

Slurry Charge Pump

FineScreen

2 independent trains

6 /Coal-Gen 2008


Slurry Charge PumpChallenge• Corrosion/Erosion of carbon

steel in contact with coal/water slurry5 outages (3.8 days) over 2 years

Solution• Pump contact components

coated with duplex stainless steel

• Check valves coated with an epoxy material

Photos Courtesy: Tampa Electric Company

7 /Coal-Gen 2008


Low-Pressure Slurry PipingChallenge• Corrosion/Erosion of carbon

steel in contact with coal/water slurryUnacceptable parts lifetime

Solution• Carbon steel slurry pipe

replaced with PE pipe• Slurry transitions extended/

treated with chromium-carbide weld overlay


8 /Coal-Gen 2008


Slurry Run Tank Agitator

Courtesy: MetalCoat, Inc.

Challenge• Erosion grove on slurry run

tank agitator bladesUnacceptable parts lifetime

Solution• Rubber membrane coating• Coating must be reapplied

every few years

9 /Coal-Gen 2008


Original TEC HTGC Subsystem

Gasifier

RadiantSyngasCooler

H PSteam

H PSteam

Scrubbed Raw SyngasTo Low Temp Cooling

SyngasScrubber

SyngasScrubber


Clean Syngas toCombutstion Turbine

Diluent N2 toCombutstion Turbine

Clean Syngas fromAcid Gas Removal

Diluent N2 fromOxygen Plant

Oxygen Coal/Water Slurry

Raw Gas/DGANExchanger

Raw Gas/Clean GasExchanger Slag + Char to

Lockhopper

CSC CSC

Challeng e

RGE plugging caused 7 shutdowns, 139 days outage

CSC plugging caused 13 shutdowns, 95 days outage

Solution Removed RGEs, Sacrificed < 40 MMBtu/hr (<2% Fuel HHV)

Proactively detect plugging/ Periodic cleanings

10 /Coal-Gen 2008

Copyright 2009 General Electric Company. All Rights Reserved. This material may not be copiedor distributed in whole or in part, without prior written permission of the copyright owner. Courtesy: Tampa Electric Company

11 /Coal-Gen 2008

Copyright 2009 General Electric Company. All Rights Reserved. This material may not be copiedor distributed in whole or in part, without prior written permission of the copyright owner. Courtesy: Tampa Electric Company

12 /Coal-Gen 2008


Improved TEC HTGC Subsystem

Gasifier

RadiantSyngasCooler

H PSteam

H PSteam

Syngas +Char toSyngas

Scrubber


Syngas +Char toSyngas

Scrubber

Slag + CharTo Lockhopper

ConvectiveSyngas Cooler

ConvectiveSyngas Cooler

H PSteam

Water Pool

Regular CSC cleaning reduced CSC forced outages to a manageable level

13 /Coal-Gen 2008


RSC SootblowersChallenge• 122 sootblowers in TEC RSC

– Six required for normal operation– Four used for startup/shutdown N2

purging• Several excess sootblowers leaked

– Syngas/nitrogen flange– Lance/RSC penetration

3 outages over 4 years

Solution• Excess blowers removed in mid-2001

Cooling water

Nitrogen

Penetration of Sootblower through RSC waterwall

Sootblower Lance


14 /Coal-Gen 2008


Syngas PipingChallenge• Corrosion/Erosion of

transitions in contact with raw syngas7 outages (14 days) over 5 years

Solution• Streamlined piping• Erosion resistant (Densit) liner


15 /Coal-Gen 2008


Solids and Water Handling

SyngasScrubbers

VacuumFlash

COSHydrolysis

KODrum

KODrum

KODrum

RSC Sump

Settlers

Recycle FlyashTo Slurry

Preparation

Coarse Slag(<10% LOI)

To Sales Clean CondensateTo Pump Seals andInstrument Purges

Brine Crystals(Ammonium Chloride)

To Disposal

Final Evaporatorand Crystallizer

Vapor CompressionEvaporator

Flash GasToSulfuric Acid Plant

SlagDrag Conveyor

and Screen

Lockhopper

CSCs

Trim CoolerSteamCondensate

Heater

Clean GasPreheater

Syngas ToAcid GasRemoval

Ammonia ToSulfuric Acid

Plant

AmmoniaStripper

ProcessCondensate

Drum

Steam

Slag +Flyash

KODrum

Grey WaterTankSettler

FeedTank

SteamCondensate To

Power Plant

Steam Condensate From Power Plant

Vacuum FlashOverheadCondenser

SlagCrusher

16 /Coal-Gen 2008


Syngas Scrubber SystemChallenge• Erosive particles/high

volumes of water resulted in scrubber leaks

14 outages (21 days) over 5 years

Solution• Corrosion resistant coatings

(weld overlay in background)

• Proactive inspection and maintenance


17 /Coal-Gen 2008


Fine Slag Disposal/Marketable SlagChallenges• Fine slag filter cake difficult to

handle, wet or dry• Consistent marketable slag

- Low (< 10%) Carbon- Free of Chlorides, Ammonia

Solutions• Recycled 100% of the residual

char to the slurry prep. unit• Added wet screening to

effectively separate char from marketable slag


18 /Coal-Gen 2008


Time to Maturity

0%

20%

40%

60%

80%

100%

0 12 24 36 48 60 72Months

TEC

0%

20%

40%

60%

80%

100%

0 12 24 36 48 60 72

Another SolidsIGCC Plant

Months

4 years

5 years

• It takes 4-5 years for FOAK plants to reach availability maturity

• Reference plant integration, control system, and simulator are aimed at reducing Time to Maturity

Source: Plant run logs, 12 Month Rolling Average

19 /Coal-Gen 2008


IGCC Deployment HistoryTechnical Feasibility

Coolwater (1984-89)

• 120 MW IGCC

• 7E Gas Turbine

• N/A time to maturity

TEC (1996 – Present)

• 250 MW IGCC

• 7FA Gas Turbine

• 5 yr time to maturity

Duke Edwardsport (2012 - )

• 630 MW IGCC

• 7FB Gas Turbine

• 1 yr time to maturity

CommercialFeasibility

CommercialDeploymentReference Plant

20 /Coal-Gen 2008


Improvements for Reference PlantMitigated• Coated feed pump internals• Improved LP slurry piping• Coated HP slurry transitions• Streamlined slurry piping• Coated run tank/agitator• Coated syngas scrubber

Eliminated• Raw gas exchangers• Convective syngas coolers• RSC Sootblowers

Incorporated• Marketable slag• 100% residual char recycle

TG1Opportunity

TG2Planning

TG3Concept Design

TG4Prelim.Design

TG5Detail

Design

TG6Ship

TG7Validate

TG8Access

GE’s New Product Introduction (NPI) Process Integrates Lessons Learned throughout the Design Process

21 /Coal-Gen 2008


Lessons learned integrated into Reference Plant

Two trains 630 MW net plant output

Optimized RSC Availability

7FB turbines Efficiency

Higher pressure CAPEX

MkVIe controls Operability

Simulator Reduced time to maturity

Improved refractory Availability

Improved feed injector Efficiency

Slurry preheat Lower O2, Efficiency

Selexol AGR Emissions approaching NGCC

GE’s IGCC

Referenc e Plant

ASU

Steam turbine

RSC

Controls

Gas turbine

Engineering

22 /Coal-Gen 2008


HTGC Subsystem

Gasifier

RadiantSyngasCooler

H PSteam

H PSteam


SyngasScrubber

SyngasScrubber


Clean Syngas toCombutstion Turbine

Diluent N2 toCombutstion Turbine

Clean Syngas fromAcid Gas Removal

Diluent N2 fromOxygen Plant


Raw Gas/DGANExchanger

Raw Gas/Clean GasExchanger Slag + Char to

Lockhopper

CSC CSC

RSC Improvements

23 /Coal-Gen 2008


RSC Improvements on Reference Plant

TECO Soot blower Deposits

Soot-Blowers – Removed from Reference Plant Design

CSC’s - Removed to Increase RAM

Seal Design/N2 Purge - Optimized for robust operation and RAM

Performance – 30% increase in steam production through surface optimization & increased steam & hot gas pressure

Size – 2 ft smaller diameter9 ft longer, same weight

Internal Quench – Experience based design, Favorable for sealing

TECO Tube Cage Leak RCA

CSC Inlet Fouling – Coating sample

Lessons Learned &

Design Improvements

TECRef. Plan

t

24 /Coal-Gen 2008


GE 630MW IGCC Ref. Plant Performance

Source: GE internal data, average of 30 permits granted, applications and publicly reported emissions, Aug 2006

Advanced PC/SCPC

IGCCcapability

NGCC0.00

0.05

0.10

0.15Average recent permit data

Best individual plant

Lb/MMBTU

• 90% + Hg removal• Useful byproducts• 30% less water

• 33% less NOx

• 75% less SOx

• 40% less PM10

IGCC reference plant benefits compared to supercritical pulverized coal

1Plant performance from Illinois #6 commercial match. Performance will vary according to specific coal and site conditions

Net Output1 634 MW

Net HR (HHV)1 8865 Btu/kWhAvailability

Target92%, 85% on

syngas

Net Eff.1 38.5% HHVTurndown 50%Coal type Eastern

Bituminous CoalFuel Envelope Up to 14% Ash

0.8 – 4% Sulfur Chlorides 2500 ppm

NOxSO2PM10

GE Ref. Plant Carbon Capture ready

Precombustiondecarbonization

H2 + CO2

GE Energy• Power• Heat

• Underground storage• Enhanced oil recovery (EOR)

CO2

26 /Coal-Gen 2008


GE Carbon Island™• Option for GE’s 630MW

IGCC plant • Allocated in plant layout• $225MM total installed cost• 585 MW output

(from 630 MW)

• 33% HHV efficient (from 38.5%)

• Tie-ins matched GT outages (Minimum plant downtime)

NG Eq. CO2 Footprint• Simple Cycle:

50% carbon capture (~1,100 lb/MWh)

• Combined Cycle: 65% carbon capture (~770 lb/MWh)

Note: Illinois Basin Coal on ISO site with proven technology…Performance and CAPEX are coal- dependant

27 /Coal-Gen 2008


Duke Energy Edwardsport IGCC Reference Plant launch customer• 630MW on Indiana 5 coal• NTP in 2007, COD in 2012• Detailed engineering near completion• Construction on-track • RSC ships in 2009• 7F Syngas turbines ship in 2010Successful siting & permitting• Sited & permitted next to aging PC facility

“ We have an opportunity to make history with the Edwardsport plant. The facility could very well be one of the cleanest coal-fired power plants in the

world. It will produce nearly 10 times as much energy as the existing Edwardsport plant with much less environmental impact.” - Jim Turner,

President & COO, U.S. Franchised Electric and Gas-Duke Energy Duke Energy press release, Jan. 25, 2008

Duke Energy Edwardsport site construction, January 2009

an igcc design improvement case study

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