ALSTOM

Flue Gas 

Desulfurization

Technologies
Agenda

z ALSTOM 

Environmental Control Sy

z FGD Technologies

– Wet Flue Gas Desulfurizat– Dry Flue Gas Desulfurizati– Seawater Flue Gas Desulf

z Summary
ALSTOM Today

Tra

Energy

The global specialist in energy and transpo

The global specialist in energy and transpo
Power

Reorganized z Power Ser

– No. 1 in – Largest 

equipme

z Power Tur

– No 1 to 

turbinespower pconstruc

z Power Env

– No. 1 in 

and hyd

– New reg

growth

Sales: 

10.9 billion euros

Orders received: 

8.4 billion euros

The Full Service Provider in Power Ge

The Full Service Provider in Power Ge
In the rear mirror

Svenska Fläktfabriken

Norsk Viftefabrikk

1920

Daneco

Widmer & Ernst

Combustion Engineering

1997

1989

ALS

AL

Alstom Energy 

Alstom Energy

ABB Als

ABB Als

ASEA 1988 Brown Boveri

ABB ABB

1000 people 1000 people worldwide with worldwide with a 600 MEU

a 600 MEU
Process Technologies

z Particulate Removal

– Electrostatic precipitators (wet and dry) & SO3 conditio– Fabric Filters

z Gaseous Emissions, FGD

– Limestone (wet), lime (wet/dry) and seawater desulfuri

z Post Combustion DeNOx

– Selective Catalytic Reduction (boilers)– SCONOx (GT)– Hug

 urea to ammonia systems

z Knowledge Based IT Solutions

– Pegasus neural network applications

z Integrated Emission / Heat Rec

overy

– ETS for petrochemical
Our Complete Solutions

z Green field, retrofit, upgrade instaz Full range of environmental syste

components & services

z Turnkey project management and 

from initial concept to handover

z Post-installation maintenance & az More than 30 years of global refe

Power plants and industrial applic
Who We Are

EuBuOs- H- V- M- M- B

HeadquartersVelizy, France

North America Business RegionKnoxville, TN USA (344)

Latin America Business RegionSao Paulo, Brazil (20)

GLOBAL Experience LOCAL Solutions ENVIRON
FGD Experience

Personnel

z International FGD Offices

z Oslo, Norwayz Vaxjo, Swedenz Milan, Italyz Sydney, Australiaz Kobe, Japanz Knoxville, USA

z Over 1500 man-years of FGD 

knowledge and experience in USA office alone

z Multi-Discipline International 

Engineering Capabilities

z Global Equipment Sourcing
ALSTOM Flue Gas Desulfurizati

Technologies

Dry Flue Ga

Spray Dr

Wet Flue Gas Desulfurization

Seawater Flue GasDesulfurization

Dry Flue Ga
Wet Flue Gas Desulfuri

Systems
Wet FGD Experience

z SO

2 Removal Efficiencies

Greater than 98%

z Availability Greater than 

98%

z Experience with Low to 

High Sulfur Fuels (4.5% S; >5,000 ppm SO

2

)

z Commercial Grade 

Byproductssuch as Gypsum orByproducts for Landfill

z Low Cost/Optimal Designz New and Retrofit Projects

Sual Units 1 Sual, Philipp
Recent WFGD References

C

ustomer Pl

a

n

t MW %S

Sa

n Anto

nio CPSB

J.K. Spru

c

e 1

5

4

6

0.6 

Isefjord

verket

A

s

n

aes 5

650 2.

5 

T

aiwan P

o

w

er C

o. Lin K

o

u 1&

2

2

x350 2.

0 

T

e

n

nes

see V

alley A

uthority

C

u

mberland 1&

2

2

x1300

4.0 

Virginia P

o

w

er Clo

ver 1&

2

2

x440 1.

7 

G

P

U-G

E

N

C

O

Conemaugh 1&

2

2

x936 2.

8 

O

hio E

dison C

o

mpan

y

Niles 133

3.5 

Z

E

P

A

K

Konin 7&

8 110 1.

0 

S

alt River Project Navajo 1,2,

3

3

x803 0.

6 

Mira

nt S

ual 1&

2

2

x609 1.

0 

E

nergotra

n

s

M

elnik I

6

x5

5

2.0 

E

N

D

E

S

A

C

o

m

postilla II 330 1.8 

K

K

A

B

K

arls

ham

n

340 3.

5 

E

G

A

T

Mae M

o

h 4-

7

4

x150 2.

4 

C

o

m

m

u

nity of R

a

n

ders

Randers 2x40 2.

0 

Tran

s

Alta/

P

a

cifiC

orp

C

e

ntralia 1 & 2

2

x730 1.

0 

E

dison Mis

sio

n E

nergy

H

o

m

er City 692

3.7 

P

P

C (

Greek P

o

w

er A

uthority) Florin

a

330 3.

0

32,900 MW Total Installed/Under C
WFGD Process Flow Diagram

STACK

SPRAY TOWER 

ABSO

R

B

E

R

T

ELEC

T

R

O

STA

TIC

PRECIPITATOR

LIMESTONE

AIR 

R

eagent: Limest

o

n

e

Byproduct: GypsumEfficiency: >97%, High S

FROM MW 

TANK

BALL MILL
Limestone/Forced Oxidation

SO

2

(Sulfur dioxide)

H

2

O

(Water)

CaCO

3

(Calcium carbonate, 

limestone)

O

2

(Oxygen)

SO

2 + CaCO

3 + 1⁄2O

2 + H

2O 

→ CaSO
Open Spray Absorber

z Countercurrent flue gas / 

scrubbing liquor

z Size/cost increases with:

– Gas flow– Sulfur inlet loading– Removal efficiency

z Materials of construction:

– Flake-lined steel– Rubber-lined steel– Stainless ste

el

– Nickel-based alloys– FRP– Tile Lined
z Liquid to Gas Ratio (L/G)

– Inlet SO2 Concentration

– SO2 Removal Requirement

– Scrubbing Liquor pH– Spray Zone Height– Spray Nozzle Characteristics– Chlorides (HCl gas)– PEP– Absorber Gas Velocity– Similar Plant Experience

z Reaction Tank

– Limestone dissolution, 

gypsum formation

– Liquid Residence Time– Solids Residence Time

WFGD Design Basis

Absorber Design 
Absorber Spray Zone

Spray Headersz Countercurrent slurry sprayz Staggered headersz Single vessel penetrationz Excellent gas / liquid contactz Excellent turndownz Low pressure lossz High reliability, low scale potentialPerformance Enhancement PlatesMaterials of Constructionz FRPz Metallic
High Efficiency with PEP

Performance Enhancement Plates (PEP)

z Prevents wall sneakagez Reintroduce wall slurryz Improves efficiency/ 

reduces L/G

z Power savings due to 

lower L/G

z FRP or alloy construction

Conventional Conventiona

Savings: 400-500 kW for 500 MW 
Spray Zone SO2 Mapping

z Differential Optical Absorption 

Spectroscopy

– Alstom proprietary– SO2 measurement inside absorber

– 1 inch space resolution– 5 ppm SO2 resolution

z Computational Fluid Dynamicsz Test Facilities

– Switzerland (Chemistry)– Sweden (Mass Transfer)– USA (CFD, Mist Eliminators)
Absorber Spray Nozzles

Spray Nozzlesz Hollow cone, ramp stylez Nitride bonded silicon carbidez 8 psig at 250-400 gpmz 90-120° Spray cone anglez 300-600% spray coveragez Droplet size range 200-2000 

microns

Laser MeasuremenSize Distribution
Absorber Recycle Pumps

Absorber Recycle Pumpsz Each pump has its own 

dedicated spray level

z Scrubber liquor flow can be 

tailored to system requirements to meet turndown needs.

z High availability with spare 

pump / level

z Heavy duty, high efficiency 

pumps (>90%)

z Newer, higher capacity 

pumps reduce FGD costs.
Advanced WFGD Features

SO

2 Re

m

o

v

al: 97%-98%

A

v

aila

bilit

y 97%-98%

G

a

s V

elo

city: 13.1 ft/s

e

c (4.0 m/s

e

c)

N

o. S

pray Elevations: 3-4 

S

pray Zone:

High ef

ficiency spr

ay 

zone; P

E

P, I

ncreased 

spr

ay height

Spra

y Pu

m

p

s: Increased capacity:

72,000+ gpm each 

Spare A

bsorber: No

A

bsorber / Stack:

C

o

m

bined 

Mist Eliminators: 2+2 Plus, K

och,

Munters 

Materials: Flakeglass or Rubber

Lined C

S, S

S or Alloy 

C276 R

oll-Clad 

O

xidation: Lance I

njection 

Reheat: NoB

yproduct: C

o

m

mercial gypsum
Limestone Preparation

Limestone grinding

• Horizontal/vertical

wet ball mills

• On-site vs. off-site

preparation

Product ground to 90-95% < 40 

μ; 30-

35% solidsRubber-lined with hardened steel balls
Single Ball Mill

z Single 100% capacity millz Pre-ground limestone silo 

provided in case of unplanned mill outage

z Most applicable to:

– Smaller units (< 500 MW)– Lower sulfur coals (< 2% S)

z Careful consideration to:

– Pre-ground limestone supply– Mill maintenance planning

Savings: $3-5 million
Limestone Preparation Island
Wallboard Gypsum Production

Typical specification:z >95% CaSO

4.2H

2

O

z <0.5-1.0% CaSO

3.1⁄2H

2

O

z <100 ppm Clz <10% moisturez pH 6 -

8

z 30-40μ MMDRequires:z High purity limestone (95-96%)z High efficiency ESPz 99+% oxidationz Belt filter or centrifugez Cake washing/purge stream
Primary Dewatering

Gypsum Hydrocyclone:z Heavy, coarse particles 

to underflow to secondary dewatering

z Lighter, fine particles to 

overflow including flyash, limestone

z No moving parts
Vacuum Belt Filter

Slurry feed

Cake wash
WFGD General Arrangement
Integrated Scrubber/Stack

z Absorber/chimney integrated 

into single structure

z Advantages:

– Lower capital cost– Smaller foo

tprint

– Shorter construction duration

z Konin Units 7 & 8

– 2 x 55 MW in Poland– Began operation in 1997– Rubber-lined/concrete 

construction

ReKA

Savings: Up to $2-5 million; 1-2 
Range of Experience

Plant Size (MW): 175 to 2,600Boiler Size (MW): 130 to 1,300Fuel Coal, lignite, OrimulsiAbsorber Size (MW): 130 to 700Sulfur Range (%): 0.5 to 4.5SO

2 Inlet Concentration: 5,200 ppm / 15,000 m

SO

2 Removal Efficiencies (%): 85 to 99

Reagent: Limestone, Lime, FlyaBy-Product: Gypsum, LandfillReheat: Wet Stack, By-Pass, Chlorides (ppm): 1,000 to 120,000FGD Make-Up Water: River, Lake, Plant Wa
Recent WFGD Proje

Details
Centralia Units 1 & 2

TransAlta

P

roj

e

ct S

cope Consortium Alliance:

absorbers, reagent prep,dew

atering, d

uctw

ork, ID

fan m

o

dification

s, sta

c

k,

buildings, ele

ctrical, DC

S

piping, BOP 

Location Washi

n

gto

n, U

S

A

Capacity 2 x 700 M

W

S

chedul

ed 

Start-Up 

Unit 2 – Dec 31, 2

001 

Unit 1 – Dec 31, 2002 

Commerci

al

Operation 

Unit 2 – Nov 16, 2001 Unit 1 – Dec 31, 2002 

Fuel 1.05% sulfur

c

oal 

SO2 R

emo

v

al 91% 

No. A

bsorbers 1 per boiler 

N

o. Spray Lev

els 3+1 

Ab

s

o

r

b

e

r Si

z

e 58 ft. (17.7 m) dia.

B

yproduct Wallboard gypsum

Highlight

s 30 mo. S

chedule; 

317LMN absorber 

TransAltaCentralia Units 1 & 2 -

2 

Lewis Count

y, WA
TransAlta Centralia Units 1 & 2

Materials of ConstructionAbsor

ber Solid 317 LMN 

Reaction Tank Solid 317 LMN Intern

al Spray 

H

eaders 

317 LMN 

Exter

n

al Spray 

Pip

e

FRP

PEP 317 LMN Outlet D

uct Solid 317 LMN 

Recycle Pumps Rubber lined casing,

metal impeller 

Inlet D

uct Alloy 276 solid, 12 feet

Mist Eliminato

rs 

F

RP, Munters 

Mist Eliminato

r

Was

h Pipe / 

No

z

zles 

FRP

Oxi

dation Air 

Lance

s

317 LMN 
Homer City Unit 3

Edison Mission Energy

A

L

S

TOM Scope Turnk

e

y: absorbers,

reagent prep, foundation

s, dewatering,

d

uctw

ork, stack, 

buildings, ele

ctrical,

piping, BOP, w

a

ste

w

ater tr

e

atm

e

nt

Location Pennsylvania, USA Capacit

y 1 x 650 M

W

Start-Up Sept 2001 Fuel 3.7% sulfur coal SO2 Remov

al 98% 

No. A

bsorbers 1 

No. Spray L

e

v

els 4+1 

Ab

s

orb

er Siz

e

5

9 ft. (18.0 m) di

a.

B

yproduct 

W

allboard gypsum

Highlights 29 mo. S

chedule; C-276 

roll-clad a

b

s

orber; S

C

R

s

on U

nit

s 1, 2, & 3.

Ediso

n Mission Energ

Homer City Unit 1 - 1 x Homer City, PA
EME Homer City Unit 3

Project Feat

u

res

• 

T

u

r

nke

y Alstom Project 

• 

Awar

d: A

pril 17, 1999 

• 

F

G

D In Service: S

eptember 21, 2001

• Per

formance Test: October, 2001 

• Single 650 M

W

A

bsorber 

• Wet FGD 

with S

CR 

• Construction M

anage

m

ent: Alstom

• Cont

r

actor

s: Chattanooga Boiler & 

Tank, M

cCall

s, D

u

k

e Fluor Daniel, 

MP

S

• 29 Month Project Sch

edule 

Ediso

n Mission E

Homer City Unit 1 Homer City, PA
Dry Flue Gas 

Desulfurizatio

SDA and NID
Alstom started DryFGD in 1980

• More 

exper

• More 

install

• Rotary 

Fluidizsystemdiffereopera

Dry Flue Gas Desulfurization

South Carolina Electric & Gas

Cope Unit 1, 385 MW
A History of Dry FGD Systems

Cir

culating fluidize

Spr

a

y absorption

100%

50%

0%

Dry absorption 

with

spra

y cool

er

Spraying reactor Fabric filter / 

Electrostaticprecipitator 

Water

Water

Lime milk

- Very big r

e

a

ctor

H

Ç

D

È

- D

u

st separator

- High energ

y con

sumpti

o

n

because of rotary

atomizer or spra

y nozzl

e

s

- Handling of lime mil

k

- A

b

sorbens: limestone

- High cooling to

w

er

H

Ç

D

È

- Dust s

e

p

arator

- No lime mil

k

-Absorbens: 

c

alcium hydrate

Spraying reactor

Fabric filter 

- Small reactor- Dust separat

or

- No lime milk, but Ca- Absorbens: calcium 

Circulating fluidized

bed reactor

Fabric fiElectrosprecipita
Alstom’s DryFGD in 2003

Formosa Heavy Industries Co. Taiwan, 2 x 150 MW NID
The NID Process
NID Process Concept

TC ESP or 

Hum

Water

R

z Very high recirculationz No slurry handlingz Direct usage of CaOz “Dry” produc

t

z High utilization of reagent
SDA and NID – Moisture 

Content in Dust

% H2O

70

Thin slurry

605040

Thick slurry

3020

Paste

10

Free flowing dust

Wet/Dry Process NID Dry Process Adsorbed equ

moisture

5

NID
NID Design Parameters

z Flue Gas SO

2 Content

8 Tested up to 3500 ppm8 Most applications are for low and medium sulfur c

z Flue Gas Inlet Temperature 

8 Low temp preferred; max approx.. 200 °C

z Gas flow 8 Operating range from 20,000 Nm3/h

8 Single Reactor module up to Nm3/h8 Parallel reactors for higher flows
NID – Advantages

z Integrated FGD and ESP or Fabric Filter z High SO2 removal efficiency z Lower operating cost than comparable sz Lower investment than ESP + Wet FGDz No separate Dust Removal system necez Less maintenance due to less equipmenz Less maintenance due to no corrosion - 

spraying and 100 % removal of SO3.
NID Standardised components
Reactor layout (NID & others )

NID •Same flow veloc

•Same lifting force •Agglomerates ar•No water sprayin

reactor/flue 

Other

•Lower velocity in reactor, accelerati•Lower lifting force •Agglomerates are extend collected in and can’t leave it•Water addition in
NID Equipment

Mixer/Hydrator

Recycle CaO

Recycle + Ca(OH)2

M

Dispersion Plate

(inside the Reactor)
NID Integrated Lime Hydrator

Principle

LimesiloCaO

Recycle

WaterLime

HydratorStage 1

HydratorStage 2
Mixer/Hydrator installation
NID Equipment - Mixer

– Mechanically Stirred Fluidised Bed– Low Specific Power Consumption ena

Large Capacity per unit

– Positive wetting of all recycle as oppo

system with wetting inside Reactor. 

– Enabling factor for CFB + NID; reside

is long enough to allow activation of a25 minutes (20 s x no. of passes)
Journey through the NID 

Reference List 

I. NID and ESPII. NID and Fabric FilterIII. NID for Waste to Energy PlantsIV. CFB Boiler and NID
NID Reference Plants

Power

Plant Fuel NmLaziska, PL 

C

oal 2 x 518

Vaasa, FI Diesel 145Nuremberg, DE Coal 168Fifoots Point, UK Coal 3 x 450Zhejiang #8, CN Coal 330Mai Liao RF-1, TW Petcoke 2 x 511Seward, US Coal 2 x 930Gilbert, US Coal 900Elektrenai #8, LI Orimulsion 520HuaYingShan, CN Coal 451Baotou #2, CN Coal 850
NID End Collector Options

FF and ESP
NID + ESP
NID-ESP, Juhua Group Co.

P. R. China
Zhejiang, Juhua

Group Co. 

Process description boiler No 8
Zhejiang, Juhua Group Co. 

NID plant data boiler No 8

Power productionMain fuelFlue gas flowTemperatureInlet SO2SO2 removal efficiency

AbsorbentDust emission, outlet NIDEnd product conveyingEnd productIn operation

Steam plus 5Coal330 000 Nm3148 °Cmax. 1 100 p85 %Ca(OH)2 alte

max. 200 mgDense phase LandfillYear 2001
NID ESP Design specials

•Low operating temperature -> insu•High dust load -> purging, rapping•Control and rectifiers

EPIC II control T/R of correct size

•Slightly higher ESP power consum

operation with low resistive coal

•Sizing of ESP: For coal case and 
NID + Fabric Filter

Vaasa Diesel Power Plant

p

r

ocess description











	




























Vaasa Diesel Power Plant
EWAG Nürnberg

Replacement of SDA with NID
EWAG Nürnberg

NID basic plant data

114 MWtCoal157 000 Nm3

140 °C1800 mg/Nm

max. 180 mgCaOmax. 10 mg/NDense phase LandfillYear 1999

Power productionMain fuelFlue gas flowTemperatureInlet SO2Outlet SO2AbsorbentDust emission, outlet NIDEnd product conveyingEnd productIn operation
NID – Laziska Basic Plant Data

2 x 120 MWCoal, max 1.4% S2 x 518.000 Nm3/165°C1,500 – 4,000 mg80% (guaranteed)95% (measured)CaO22,000 mg/Nm3 (50 mg/Nm3 (guar15 mg/Nm3 (measStabilisate/fire preDense phase pne1,200 m (tested)

Power productionMain fuelFlue gas flowTemperature, maxSO2 inletSO2 removal efficiencySO2 removal efficiencyAbsorbentDust load, inlet NIDDust emission, outlet NIDDust emission, outlet NIDEnd product utilisationEnd product conveyingConveying distance
Fifoots Point - Exterior
AES Fifoots

Point 

NID Layout
NID – Fifoots Point Plant Data

3 x 120 MWCoal, 1.2% S3 x 450.000 Nm133°C800 ppm80% (guaranteeCaO25 mg/Nm3 (guDense phase p

Power productionMain fuelFlue gas flowTemperatureSO2 inletSO2 removal efficiencyAbsorbentDust emission, outlet NIDEnd product conveying
Mai Liao Site sept 2002
Mai Laio - Control Screen
Seward, USA

NID for CFB 2*250 MW
Seward, USA 

NID - Technical data

Type CFB + NIDSize 2*250 Gas flow 2*906 000 In operation Dec 2003Emissions guaranteesDust 10 SO2 emission 318 SO2 removal overall 95 (Boiler + NID)
ALSTOM Technology moves on

NID Pilot Plant in Alstom’s LaboratoryR+D test runs lead to new developme
ALSTOM Seawater F

30 years operation and devel
Successful applications

Seawater avaLow-medium s

Coal and Oil-firMetal smeltersOil industry
Seawater FGD Process Diagram

STACK

ABSO

R

B

E

R

ELEC

T

R

O

STA

TIC

PRECIPITATOR

AIR

SEAWATE

R

TREATMENT P

SEAWATE

R FROM 

BOILE

R CONDENSERS

R

eagent

ByproduEfficienc
Process flow
Absorber design
Water treatment plant
Seawater FGD

z Utilizes natural 

alkalinity of seawater

z High efficiency via 

packed tower

z No reagent, no 

byproduct

z Effluent treated via 

oxidation prior to discharge
Recent SWFGD References

Customer Fuel MW 

UNELCO Tenerife, SP 

Oil 2 

x 160 

Shenzhen West Power Unit 4, CN 

Coal 300 

Mitsui Paiton, ID 

Coal 2 

x 670 

TNBJ Manjung, MY Coal 3 x 700 Shenzhen West Power Unit 5 + 6, CN 

Coal 2 

x 300 

Vasilikos II EA Cyprus Oil 130 

Over 8,000 MW Operating or Unde
Shenzen West SWFGD
Summary
FGD Alternatives

WFGD DFGD - SDA DFGD - N

InstalledCapacity

33,000 MW 12,000 MW 3,000 MW 

First Installation 1968 1980 1996 Reagent Limestone Lime Lime 

(Limestone wit

Byproduct Salable gypsum or 

landfill 

Landfill Landfill or U

Cement/Road 

Sulfur <6% <2.5% <6% RemovalEfficiency

>98% 90-95% 90-95% 

(98% w/CF

Footprint Small in power island 

area; large overall 

Large in power island area; small overall 

Small in power area and overa

Pros • Low cost reagent 

• Marketable

byproduct 

• Large reference list• Fuel flexibility• Ease of retrofit 

• Low capital cost • Low power 

consumption 

• Dry byproduct• Operational 

simplicity, mediummaintenance costs 

• Low capital c• Low power 

consumption 

• Dry byproduc• Operational 

simplicity, lowmaintenance 

Cons • High capital cost

• High power 

consumption 

• High cost reagent• Byproduct use

limited 

• High cost rea• Byproduct us

limited 
Why ALSTOM?

z A diverse portfolio of proven FGD 

technologies

– Wet Flue Gas Des

ulfurization

– SDA Dry Flue Gas Desulfurization– NID Dry Flue Gas Desulfurization– Seawater FG

D

z Numerous and recent references in all 

technologies with over 55,000 MW of FGD installations

z Experience over a wide range of site 

and process conditions

z FGD personnel and offices located 

around the world with both FGD and large project capability
Karlshamn Full Scale 

Experience

9 Start-up:

November 1996

9 340 MW Flowpac WFGD9 Patent Owner: Alstom

New Developments
No Recycle Pumps

oapp
Flowpac Advantages

• 97-98% SO

2 collecting efficiency 

with high sulfur content. Excellent reagent utilization.

• 70% SO3 removal and high 

particle collecting efficiency 

•

No scaling or corrosion 

problems

• Lower maintenance and 

supervision costs due to low overall height and absence of slurry pumps, absorber headers, and nozzles

Karls