p. 1



# OAR Box 

# 1828
Prepped by Ollie Stewart



### Document

Number: 

# 297 ) IV-A- 7
Docket Number: 

# A-83-2 7

Printed 11/12/200811:12:59AM Sheet 297 of 3251

- A 

# A-^-2 7

TECHNICA L NOT E

PARTICULAT E MATTE REMISSION S FRO M RESIDUAL OIL-FIRE D BOILER S

Prepare dfor : Mr . Charle s Sedma n Industria l Studie s Branc h Emissio nStandard s an

dEngineerin g Divisio n U . S . Environmenta l Protectio nAgenc y Researc hTriangl e Park , Nort hCarolin a 2771 1

Prepare dby : Radia nCorporatio n 320 0 E . Chape l Hil l Road/Nelso nHighwa y

Pos t Offic e Box1300 0 Researc hTriangl e Park , Nort hCarolin a 2770 9

Jun e 4 , 198 4

xP. 3

- I

•1. 0 INTRODUCTIO N

Thi s technica l not e review s th e capabilit y o f residua l oil-fire d boiler s t o achiev e low level s o f particulat e matte r (PM ) emissions . Sectio n2. 0 characterize s P M emission s from

low-sulfu r residua l oi l combustio nan

dth e effect s o f goo dboile r operatio nincontrollin g thes e emissions . Sectio n3. 0 characterize s th e performanc e o f fiv e we t scrubbe r type s i ncontrollin g P M emission s fro

m residua l oil-fire dboiler s firin g moderate - t o high-sulfu r residua l oil s (whic hcharacteristicall y exhibi t highe r uncontrolle dP M emissions) .P. 4

2. 0 LO W SULFURRESIDUA L OI L COMBUSTIO N
Ai r Pollutio nManua l - 42 , "Compilatio no f Ai r Pollutan t Emissio n Factors " an

d other report s hav e note dtha t P M emission s fro

m residua l oi l combustio nar e proportiona l t o th e sulfu r leve l i n th e fue l oil , wit hlow sulfu r residua l oil s exhibitin g th e lowes t P M emission s rate . Thus , th e us e o f low-sulfu r residua l oil s coul db e a feasibl e P M emissio ncontro l techniqu e i f the y

exhibi t sufficientl y lo w uncontrolle dP

M emissions . T o understan dan

d predic t P

M emission s fro

m residua l fue l oi l combustion , informatio ni s neede don ho w P M emission s ar e generated . Ther e ar e fou r source s o f P

M emission s fro

m fue l oi l combustion . Thes e sources , discusse d i nth e followin g sections , are : 1 ) iner t as hin th e oil , 2 ) sulfate s an d sulfite s forme dfro

m th e combustio no f sulfu r i n th e oil , 3 ) carbonaceou s compound s forme dfro

m incomplet e combustio no f th e oi l itself , an d 4 ) oi l 2 3 additive s use d t o protec t th e boiler . '

2. 1 INER T AS H

Iner t as hconsist s o f th e non-combustibl e compound s whic hnaturall y occur in fue l oils . Thes e compound s ar e metal s an d salt s tha t rang e in

4 concentration s fro

m les s tha n0.0 1 t o approximatel y 0.2 0 lb/MMBtu . Th e amoun t o f as hpresen t in fue l oil s i s generall y proportiona l t o th e sulfu r content . Fo r low-sulfu r residua l fue l oil s wit hsulfu r content s les s tha n 1. 0 weigh t percen t (1. 0 weigh t percen t fue l oi l woul dhav e a potentia l S0 2 emissio nrat e o f roughl y 1. 1 l bS0 9 /MMBt u hea t input) , th e as hconten t 1 3 generall y

range s fro

m 0.0 1 t o 0.0 3 lb/MMBtu . ' As hca n b e remove dfro m th e fue l oi l durin g refinin g a t a petroleu m refinery . Modification s t o th e combustio nproces s hav e negligibl e impac t o n th e amoun t o f fl y as hforme d durin g combustion .P. 5

2. 2 SULFIT E AN D SULFAT E
Sulfit e an

dsulfat e component s o f P M emission s ar e th e indirec t resul t o f elementa l sulfu r inth e residua l fue l oi l formin g S0 2 an dS0 3 durin g combustion . Roughl y

1 t o 4 weigh t percen t o f thes e sulfu r oxid e gase s reac t wit hmetal s i

nth e fl y

as han dmeta l boile r component s t o for m metalli c 2 5 sulfit e an

dsulfat e salts . ' Thes e sulfu r salt s exi t a s P M emission s in th e flu e gas . Sulfite s an dsulfate s generall y

contribut e P

M emission s o f les s tha n0.0 3 lb/MMBt ufo r low-sulfu r oi l combustio n(les s tha n1 weigh t percen t sulfur ) an

d0. 1 lb/MMBt ufo r high-sulfu r oi l ( 3 weigh t percen t sulfur) .
2. 3 CARBONACEOU S MATERIA L COMPONEN T

A tar-lik e carbonaceou s materia l consistin g o f polymerize doi l compound s result s fro m incomplet e combustio no f residua l fue l oil . Thi s unburne dcarbonaceou s componen t ca naccoun t fo r a s muc ha s 9 0 weigh t percen t o f th e P M emission s fro

m a poorl y

operate dresidua l oil-fire dboiler . Th e formatio no f carbonaceou s materia l ca nb e reduce db y u pt o 3 0 percen t b

y th e us e o f efficien t oxyge ntri m controls , routin e boile r maintenanc e o procedures , and/o r th e us e o f highe r performanc e burners . 2. 4 ADDITIV E COMPONEN T
Occasionally , alkalin e additive s ar e blende dint o residua l oil s t o improv e boile r operation . Mos t additive s reduc e th e corrosiv e impact s o f S0 2 , whic hi s forme ddurin g combustio no f sulfu r inresidua l oils . Additive s ca nals o b e use dt o reduc e th e slaggin g effect s o f some high-as h residua l oils . Whe nuse dwit hhigh-sulfu r oils , additive s ca ncontribut e a s muc ha s 0.0 4 lb/MMBt uo f P M emissions . However , additive s ar e no t generall y require dfo r residua l oil s wit hles s tha n1 percen t sulfur .P. 6

2. 5 PROJECTE D P

M EMISSION S

Th e contribution s discusse dabov e fo r th e fou r primar y component s o f P

M emission s ca nb e combine dt o projec t tota l P M emission s fro

m residua l fue l oi l combustion . Tabl e 2- 1 present s th e rang e an daverag e contributio n expecte dfro

m eac hcomponen t fo r residua l fue l oil s containin g les s tha n 1 weigh t percen t sulfur . I t i s als o assume dtha t th e boile r i s wel l operate d(i.e. , applyin g prope r desig nan doperatin g procedure s t o reduc e carbonaceou s P

M emissions) . Fro

m Tabl e 2-1 , th e expecte drang e o f P M emission s i s fro

m 0.0 1 t o 0.0 9 lb/MMBt uwit ha mea nvalu e o f 0.0 6 lb/MMBtu .
2. 6 P M EMISSION S DAT A

BAS E
Emissio ntes t result s fo r 1 8 residua l oil-fire dboiler s ar e presente d inTabl e 2-2 . Thes e boiler s fire dresidua l fue l oil s wit hsulfu r content s les s tha n1. 0 weigh t percen t an dhadhea t inpu t capacitie s large r tha n 4 7 5 MMBtu/hour . Th e tes t dat a wer e collecte dusin g EPA Metho d5 . Th e averag e P

M emission s wer e 0.0 7 lb/MMBtu . Fo r 1 5 o f th e 1 8 boilers , P M emission s range dfro

m 0.0 2 t o 0.1 0 lb/MMBtu . P M emission s exceede d 0.1 0 lb/MMBt ufro

m 3 units , probabl y

fro m carbonaceou s material s forme d durin g incomplet e combustion . Tw o Bosto nEdiso nunit s exhibite dP M emission s o f 0.1 5 an d 0.1 9 lb/MMBtu . Thes e wer e identica l steam-atomize dboiler s combustin g identica l fue l oils . However , tw o othe r Bosto nEdiso nboilers , on e large r an don e smaller , exhibite dP M emission s o f 0.0 4 an d0.0 7 lb/MMBt uhea t inpu t whe ncombustin g th e same fue l oil . Sinc e al l fou r unit s wer e combustin g th e same fue l oil , th e differenc e inPM emission s betwee nth e fou r boiler s wa s mos t likel y

cause db

y carbonaceou s materia l forme ddurin g incomplet e combustion . Bot hunit s wer e ol da t th e time o f th e tes t an dhav e sinc e bee n retired . A representativ e o f th e Bosto nEdiso nCompany state dtha t bot hunit s 9 ha da histor y

o f hig hP

M emissio nlevels . Th e fue l injectio nnozzle s i n th e unit s di dno t full y atomiz e th e oil , resultin g inlarg e oi l droplet sP. 7

TABL E 2-1 . EXPECTE D P M EMISSION S FRO

M LOW-SULFURRESIDUAL FUE L OI L COMBUSTION

I N A WELL-MAINTAINE D AND OPERATE D BOILER 3

P M Emissio nRang e Averag e PM fi Emission s P M Emissio nComponen t (lb/10 DBtu ) (lb/10 ° Btu )
As h0.0 1 - 0.0 3 0.0 2

Sulfite s an

d Sulfate s 0.00-0.0 2 0.0 1

Carbonaceou s 0.00-0.0 3 0.0 2

Additive s 0.0 0 - 0.0 1 0.0 1
Tota l 0.0 1 - 0.0 9 0.0 6
Engineerin g estimat e base d o ninformatio ninReference s 1- 3 an d 9 .TABL E 2-2 . EMISSIO N TES T RESULT S FO

R LO W SULFU R RESIDUA

L FUEL-OI L BOILER S

cn Owne r an

d Locatio

n Uni t

Designatio

n Capacity (1 0 Btu ) Fue l

S (wt . %) Averag e

P M Emission s lb/10 ° Bt

u Numbe r o f Test s Additive s

Bosto n Ediso n Co : L Stree t

Knee l an d Stree t M1no t Stree t
Mysti c

Compan y A : Statio

n No . 2

Statio n No . 1 Bralntre e Electric : Alle n St .

Potte r Statio

n

Eastma n Gelatin : Peabod

y
Average Values : 6 8 7 4 7 5 7 6 4
6 7 3 5 5+ 6 11+1 2 1+ 2
2+ 3 4+ 5 1 2 4 5 14 0

37 6 70 5 37 6 51 7 23 5 23 5 47 0 1,36 0 14 1 18 8 23 5 18 8 18 8 18 8 11 2 9 4 9 4 0.5 0

0.5 0 0.5 0 0.5 0 0.5 0 0.5 0 0.5 0 0.5 0 0.5 0 0.4 7 0.4 7 0.4 2 0.8 7 0.8 9 0.9 1 0.8 9 0.8 9 0.9 3 0.6 2 0.0 4

0.1 9 0.0 7 0.1 5 0.0 2 0.0 2 0.0 4 0.0 8 0.0 7 0.1 0 0.0 4 0.0 4 0.0 8 0.0 5 0.0 7 0.1 4 0.0 7 0.0 7 0.0 7 1

1 1 2 3
1 , 2
2 5 3 3 3 3 3 3 3 3 3zzzzoooo



### N o
N o N o
N o N o
N o N o Ye s
N o N o
Ye s Ye s
N o N o

NOTE : 1 . Al l P

M emission s measure

d usin g EP A Standar

d Metho d 5 . 2 . Al l Bt

u value s are base

d o n heat Input .P. 9

tha t di dno t combus t completel y an dforme dcarbonaceou s material . However , verificatio no f thes e assumption s wa s no t conducte db y Bosto nEdison . On e boile r a t Braintre e Electric' s Statio nNo . 2 als o exhibite dhighe r tha nexpecte dP

M emission s o f 0.1 4 lb/MMBtu . Th e othe r thre e unit s a t Braintre e hademission s tha t average d0.0 7 lb/MMBtu . Th e fou r unit s wer e usin g similar , bu t no t identical , fue l oils . Fue l sulfu r content s range d fro m 0.8 7 t o 0.9 1 weigh t percent . Two fuel s containe dadditive s an dtwo di d not . A s wit hth e Bosto nEdiso nboilers , th e relativel y highe r emission s fro m th e Potte r Statio nNo . 2 boile r ar e mos t likel y attributabl e t o carbonaceou s materia l fro m incomplet e combustion .P.1 0

2. 7 REFERENCE S

, U . S . Environmenta l Protectio nAgency . "Compilatio no f Ai r Pollutan t " Emissio nFactors. " Publicatio nNo . AP-42 . Researc hTriangl e Park , Nort hCarolinal . Februar y 1976 . 2 . Smith , W . S . Atmospheri c Emission s fro m Fue l Oi l Combustion . U . S . Departmen t o f Healt hEducatio nan dWelfare , Divisio no f Ai r Pollution , Cincinnati , Ohio . Novembe r 1962 . p . 16 . 3 . GCA Corporation . Particulat e Emissio nContro l System s fo r Oil-Fire d Boilers . Prepare d fo r U . S . Environmenta l Protectio nAgency . EPA-450/3-74-063 . Decembe r 1974 . p . 40 . 4 . Referenc e 3 , p . 68 . 5 . Roy F . Weston , Inc . Characterizatio no f Particulat e Emission s fro m Refiner y Proces s Heater s an

d Boilers . AP I Publicatio nNo . 4365 . Washington , D . C . Prepare dfo r America nPetroleu m Institute . Jun e 1983 . p . 32 . 6 . Referenc e 2 , p . 38 . 7 . Referenc e 2 , p . 36 . 8 . Offen , G . R. , e t al . Contro l o f Particulat e Matte r fro m Oi l Burner s an d Boilers . U . S . Environmenta l Protectio nAgency , Researc hTriangl e Park , Nort hCarolina . Publicatio nNo . EPA-450/3-76-005 . Apri l 1976 . p . 4-34 . 9 . Telecon . Wehrum , W . L . Radia nCorporation , wit hGravallese , P. , Bosto nEdiso nCompany . Ma y 3 , 1984 . Discussio no f Unit s 7 4 an d7 6 a t th e Bosto nEdiso nL Stree t facility .P.1 1

3. 0 PARTICULAT E MATTE RCONTRO L B YSCRUBBER S

3. 1 DAT A

SUMMAR Y

T o determin e th e effectivenes s o f we t scrubber s incontrollin g P M emission s fro

m oil-fire d boilers , informatio nfro m 2 2 test s wa s compile do n 1 1 scrubber s representin g fiv e scrubbe r types . Thi s information , whic hi s presente d inTabl e 3-1 , include s operatin g parameters , fue l composition , an d remova l efficiencie s fo r bot hP M an d S0 2 emissions . Th e boiler s fire d medium - t o high-sulfu r fue l wit hsulfu r content s rangin g fro m 1. 1 t o 2. 8 weigh t percent . Th e individua l boile r capacitie s rang e fro m 2 2 t o 5 7 MMBtu/hou r an

d operate d a t a

naverag e 91. 2 percen t o f capacity . Th e scrubber s trea t flu e ga s fro m singl e o r multipl e boiler s equivalen t t o tota l capacitie s rangin g fro m 2 2 t o 25 0 MMBtu/hour . Th e averag e S0 2 remova l efficienc y

wa s 95. 2 percen t wit ha rang e o f 87. 5 t o 99. 9 percent . Al l th e scrubber s adde d causti c t o th e scrubbin g liquo r t o remov e S0 2 ; causti c doe s no t affec t P

M removal . P M emission s inTabl e 3- 1 wer e measure d usin g Metho d5 . I t ha s bee n found tha t Metho d 5 inherentl y overstate s P

M emissions , becaus e sulfuri c aci d condense s i nth e samplin g system an d i s measure da s PM . T o alleviat e thi s problem , Metho d 5 bha s bee ndevelope dfo r measurin g P M fro m fossi l fuel-fire d sources . I nMetho d 5b , th e temperatur e o f th e samplin g system i s maintaine d abov e th e sulfuri c aci d dew poin t s o tha t condensatio ndoe s no t occur . Sinc e thes e P M emission s wer e measure dwit hMetho d5 , the y ar e highe r tha nactua l P M emissions ; thus , th e scrubber s presente dher e ar e mor e effectiv e i nP

M remova l tha nth e dat a indicate . Fou r type s o f scrubber s achieve d P M emissio nrate s rangin g fro m 0.0 5 t o 0. 1 lbs/MMBtu ; emission s fro m th e fift htyp e range dfro m 0.1 6 t o 0.4 3 lbs/MMBtu . Thi s indicate s tha t fou r o f th e fiv e scrubbe r type s ca n effectivel y

contro l bot hS0 2 an dPM . Th e followin g section s revie w th e variou s scrubbe r design s an d discus s thei r performance s wit hrespec t t o P M emissions .TABL E 3-1
. CAUSTI C SCRUBBE R DAT A

Mobi l

Ge n A-l ,

C-5 0

Unio n #12 ,
#23 ,
#24 ,
#30 ,
#33-37 , #22- 4

#24 - #24 - #30 - #30 - Ru n Ru n Ru n Ru n Ru n Ru n Ru n Ru n Ru n Ru n Ru n

Ru n

Ru n Ru n Ru n - 1

- 3

- 7

- 7 1 3 5 6 1 3 1 2 1 2 1

1

2 4 6 Boiler Capacity (MMBtu/hr )
2 2 2 2 5 0 5 0 5 0 5 7 5 7 5 7 5 7 5 7 5 7 . 5 0 5 0 25 2 5 5 0 5 0 5 0 5 0 5-5 0 5-5 0 5-5 0 Percent

Loa d
7 1 9 7 9 8 105 10 1 8 6 8 3 7 0 8 0 10 4 10 6 9 2 9 0 9 1 9 2 8 7 8 4 9 0 9 2 9 0 9 0 8 9 Testin

g Perio d (hour )
2. 5 2 3 3. 5 3

1. 6 1. 6 1. 0 1. 0 1. 3 1. 3 1. 6 1. 6 1. 6 1. 6 1. 6 Fue l

Sulfu r (wt
. %)
1.5 6 1.6 5 1.3 9 1.5 8 1.6 6 1. 1 1. 1 1. 1 1. 1 2. 8 2. 8
1.6 5 1.6 5 1.4 6 1.4 6 1.4 6 1.4 6 1.3 4 1.3 4 1.1 4 1.1 4 1.1 4 Percen t

SO Remova l
87. 5 90. 7 96. 8 89. 7 95. 8 99. 0 99. 0 99. 0 99. 9 99. 9 99. 9 9 5 9 5 9 8 9 8 9 6 9 6 9 2 9 2 9 9 9 9 9 9 Controlle

d P M Emission s (lb/hWBtu )
0.2 1 0.4 3 0.2 1 0.1 7 0.1 6 0.0 4 0.0 4 0.0 6 0.0 7 0.0 6 0.1 3 0.0 8 0.0 6 0.1 0 0.0 6 0.0 7 0.0 9 0.0 9 0.0 9 0.0 6 0.0 7 0.0 6 Percent P M Remova l

9 1 9 2 7 6 7 0 89. 3 77. 5

8 3 6 5 7 3 L/

G (gal/100 0 acf )
9. 9 8.1 5 8.4 5 10. 0 7. 9

16 0 16 0 2 0 2 0 4 5 4 5 16 0 16 0 2 0 2 0 2 0 Mobi l chevro n Mobi l chevro

n Mobi l chevro

n Mobi l chevro

n Mobi l chevro

n Stea m ventur i Stea m ventur i Stea m ventur i Stea m ventur i Stea m ventur i Stea m ventur i Scrubbe r Typ e

tra y towe r ( 2 trays ) tra y towe r ( 2 trays ) tra y towe r ( 3 trays ) tra y towe r ( 2 trays ) tra y towe r ( 3 trays ) educto r withspra

y towe r educto r withspra

y towe r educto r withspra

y towe r educto r withspra

y towe r educto r withspra

y towe r educto r withspra

y towe r Heate r Tec

hcausti c scrubber , ventur i Heate r Techcausti c scrubber , ventur i
Koc hcausti c Kochcausti c Anderse n 200 0 Anderse n 200 0 scrubbe r tra y towe r ( 3 trays ) scrubbe r tra

y towe r ( 3 trays ) causti c scrubber , spra y baffl e causti c scrubber , spra y baffl e Heate r Techcausti c scrubber , ventur i Heate r Tec

hcausti c scrubber , ventur i
Koc hcausti c Kochcausti c Koc hcausti c scrubber , tra y towe r ( 3 trays ) scrubber , tra

y towe r ( 3 trays ) scrubber , tra

y towe r ( 3 trays )

toP.1 3

3. 2 CHEVRO N

TRA YSCRUBBE R

Th e scrubbe r desig ntha t prove dleas t effectiv e wit hrespec t t o P M remova l i s th e chevrontra y scrubber . Thi s scrubbe r wa s designe db y Mobi l Oi l an dwa s manufacture db y Mustan g Engineering . Th e scrubbe r consist s o f
a vertica l cylinde r 1 8 fee t highan d5 fee t i ndiameter . Fro m on e t o thre e tray s ar e fixe da t regula r interval s withi nth e cylinde r ina chevro n configuration . Causti c solutio ni s introduce dint o a wei r abov e th e to p tray . Th e solutio ncascade s dow nthroug hth e colum

nan di s pumpe dou t a t th e bottom . Th e flu e ga s fro m th e boile r i s draw

nthroug hth e colum

nb y a fana t th e to po f th e column . A mis t eliminato r i s locate dnea r th e to po f th e colum

nbetweenth e to ptra y an dth e fan . Tes t dat a wer e obtaine dfro m fou r boiler s tha t us e chevro ntra y 2 scrubber s fo r emissio ncontrol . Two o f th e boiler s hav e a 2 2 MMBtu/hou r hea t inpu t capacit y

an dtwo ar e rate da t 5 0 MMBtu/hour . Th e boiler s operate da t anaverag e 94. 4 percen t o f ful l load . Th e sulfu r conten t range d fro m 1.3 9 t o 1.6 6 weigh t percen t an daverage d1.5 7 weigh t percent . Thi s scrubbe r ha danaverag e S0 2 remova l efficienc y o f 9 2 percent . Tower s wit h thre e tray s performe dsignificantl y bette r wit hrespec t t o SO , remova l tha n 2 thos e wit htwo trays . Controlle dP

M emission s range dfro m 0.1 7 t o 0.4 3 lbs/MMBt uhea t input . Th e numbe r o f tray s hadlittl e impac t o nP M remova l efficiency . A two-tra y towe r installe dona 5 0 MMBtu/hou r boile r emitte dP M a t a rat e o f 0.1 7 lb/MMBtu . Th e same scrubbe r wit hthre e tray s emitte dP M a t a rat e o f 0.1 6 lb/MMBtu . Ther e ar e a numbe r o f reason s fo r th e relativel y inefficien t P

M contro l performanc e o f th e chevro ntra y scrubber . On e facto r i s th e lo w liquid-to-ga s (L/G ) rati o relativ e t o simila r tra y scrubbers . Th e L/ Grati o

3 o f th e chevrontra y

scrubbe r wa s les s tha n1 0 gallon/1,00 0 f t , compare dt o 3 2 0 t o 16 0 gallon/1,00 0 f t fo r th e othe r scrubbers . Sinc e P M remova l i s a functio no f liqui dan dga s contact , a larg e L/ Grati o woul dincreas e th e probabilit y

tha t a particl e woul dcontac t th e liquid . Therefore , a highe r L/ Grati o woul dincreas e P M remova l efficiency .



### 1 1P.1 4

A secondmajo r facto r i s th e configuratio no f th e tray s inth e chevro n tra y scrubber . Particularl y highP M remova l ca nb e obtaine db y acceleratin g fin e liqui ddrop s int o th e P M inth e ga s stream . Thi s i s usuall y accomplishe db

y passin g th e flu e ga s an dliqui dthroug ha ventur i openin g o r b y passin g th e ga s throug ha high-pressur e liqui dspray . Thes e method s hav e bee nemploye di nothe r scrubbers , bu t wer e no t use dinth e chevro ntra y tower . Inthi s scrubber , th e ga s strea m enter s th e colum

nthroug ha duc t nea r th e bottom . Causti c solutio ni s introduce da t th e to pandflow s throug heac ho f th e thre e tray s t o th e holdin g tan k a t th e bottom . Liquid-ga s contac t occur s insid e th e chevro ntray s a s th e liqui dan dga s trave l counter-currently . Th e tray s provid e a larg e liqui dsurfac e area , whic hpromote s ga s absorption . Thi s wa s verifie db y th e dro pinSO - remova l efficienc y

whe na tra y

wa s removed . However , sinc e ver y littl e turbulenc e o r acceleratio ni s achieved, th e chevro ntra y scrubbe r doe s no t perform wel l a s a particle-liqui dcontactor . Thi s i s supporte db y th e poo r correlatio n betwee nth e numbe r o f tray s an dP M remova l efficiency .
3. 3 VENTURI TRA

YSCRUBBE R

Th e ventur i tra y

scrubbe r presente dinFigur e 3- 1 i s manufacture db y Koch , Inc . Th e scrubbe r consist s o f a ninductio nfanfollowe db y a vertica l colum ncontainin g a spra y stage , thre e ventur i trays , anda mis t eliminator . A ventur i tra y

i s a horizonta l tra y perforate dwit hmany smal l holes ; eac h hol e i s shape dt o produc e a ventur i effect . Th e ne t resul t o f thes e man y smal l Venturi s i s th e same a s tha t o f a singl e larg e venturi . Causti c solutio nenter s th e colum nabov e th e to ptra y an dthroug hspra y

nozzle s 3 below th e firs t tray . Th e L/ Grati o o f thi s scrubbe r average s 2 0 gal/1,00 0 ft 3 . 4 5 Tes t dat a wer e obtaine dfro m two ventur i tra y

scrubbers . ' On e scrubbe r wa s installe dona 2 5 MMBtu/hou r boiler . Th e othe r scrubbe r serve s fiv e 5 0 MMBtu/hou r boilers . Th e boiler s operate da t 8 9 t o 9 2 percen t o f tota l capacity . Th e sulfu r conten t o f th e oi l range dfro m 1.1 4 t o



### 1 2r-^r Scrubbe r Liquo r (Recycled ) 

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### < B -

Recycle Disposa l Pum p Stac k (Outlet )

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Causti c Make-Up/ p H Controlle d Fres hWate r Make-U p/ Floa t Controlle d By-Pas s Valv e (Ope nFo r Ga s Fired )

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# N Transitio n (Inlet )

25,000.00 0 BTU/H R SteanGenerato r



### Figur e 3-1 : Koc hFlu e Ga s Scrubbe r System .P.1 6

1.4 6 weigh t percent . Th e S0 2 remova l efficienc y fo r thi s scrubbe r desig n range d fro

m 9 8 t o 9 9 percent . Emission s o f P M average d0.0 7 lb/MMBt uan d range d fro

m 0.0 6 t o 0.1 0 lb/MMBtu .
3. 4 STEA

M VENTUR I EDUCTO RWIT H A SPRA YTOWE R

A s show ninFigur e 3-2 , thi s scrubbe r desig nconsist s o f a stea m injectio neducto r jet , an d a vertica l spra y

tower . Two baffle s inth e firs t stag e o f th e towe r creat e turbulenc e inth e ga s strea m an dpromot e liquid-ga s interaction . Th e ga s the nproceed s throug hthre e counter-curren t spray stages . Next , i t passe s throug ha cocurren t spray an da mis t eliminator ; finally , i t i s vente dt o th e atmosphere . Dat a wer e obtaine d fro m tw o 5 7 MMBtu/hou r boiler s wit hstea m ventur i educto r scrubbers . Th e boile r loa drange dfro m 7 1 t o 10 6 percen t o f capacity . Th e fue l containe d 1. 1 an d2. 8 weigh t percen t sulfur . Thi s uni t average d ove r 9 9 percen t SO ~ remova l efficiency . Emission s o f P M range d fro m 0.0 4 t o 0.1 3 lb/MMBt u an d average d0.0 7 lb/MMBtu . Th e stea m ventur i
an d fou r stage s o f hig hpressur e spray s contribute dt o th e low P M emissions .
3. 5 VENTUR I CAUSTI C SCRUBBE R
Thi s ventur i scrubber , show ninFigur e 3-3 , i s manufacture db y Heate r Technology , Inc . Th e scrubbe r consist s o f a stea m ventur i followe db

y a chambe r partiall y

fille d wit hcausti c solution . A se t o f baffle s direc t th e ga s ont o th e surfac e o f th e solution . Th e ga s the ntravel s throug ha mis t eliminator , u

p a stack , an

d throug hanothe r mis t eliminator ; finally , i t i s 3 vente d t o th e atmosphere . Emission s dat a wer e obtaine d fro m tw o 5 0 MMBtu/hou r boiler s equippe d wit ha ventur i causti c scrubber . Th e boile r loa drange dfro m 9 0 t o 9 2 percen t o f tota l capacity . Th e sulfu r conten t o f th e oi l range dfro m 1.3 4 t o 1.6 5 weigh t percent . Thi s scrubber-typ e achieve dS0 2 remova l efficiencie s o f 9 2 t o 9 5 percent . Emission s o f P M range dfro

m 0.0 6 t o



### 1 4o

n Controlle d By-Pas s Dampe r

Flu e Ga s Fro

m Stea m Generato r /

(Inlet ) \ Stea m Injectio n Je tNozzle

Recycl e Pun p Recycl e Pum p

Figur e 3-2 : STEA M VENTUR I EDUCTO R WIT H SPRA Y TOWE RP.1 8

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0 1Spra y Manifol d(1 5 Nozzles )

Recirculatio nTank Disposal Mist Eliminato r

Figur e 3-4 : Struthers-Anderse n Spray-Baffl e Scrubbe r System
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0.0 9 lb/MMBt u an d average d 0.0 8 lb/MMBtu . Th e lo w P M emission s resul t fro m th e turbulenc e i nth e ventur i an dth e impactio no f P M ont o th e surfac e o f th e causti c solution .
3. 6 SPRA

YBAFFL E SCRUBBE R

Th e spra y

baffl e scrubber , manufacture d b y Anderse n2000 , Incorporate d an d show ninFigur e 3-4 , consist s o f a high-pressur e spra y ventur i an

da horizonta l column . Th e colum nha s si xhemispherica l baffle s place da t regula r intervals . Eac hbaffl e i s off-se t 9 0 degree s fro m th e previou s on e t o produc e cycloni c ga s flow . Th e baffle s als o provid e a surfac e wher e P M impact s an

d adheres . Fiftee nhig hpressur e nozzle s spra y causti c solutio n int o th e colum

nbetwee nth e firs t an d las t baffle . Afte r passin g th e las t baffle , th e ga s passe s throug ha mis t eliminato r an di s vente dt o th e atmosphere . Emissio ndat a wer e obtaine d fro m on e spra y

baffl e scrubbe r ona 5 5 0 MMBtu/hou r boiler . Th e boile r operate da t 85. 5 percen t o f tota l capacity . Th e fue l oi l had a sulfu r conten t o f 1.4 6 weigh t percent . Th e SOp remova l efficienc y o f th e spra y

baffl e uni t wa s 9 6 percen t an dP M emission s average d 0.0 8 lb/MMBtu . Effectiv e P M remova l i s obtaine dvi a th e venturi , th e hig hpressur e sprays , an dth e baffles .
3. 7 CONCLUSIO N

Fou r o f th e fiv e scrubbe r type s examine dinthi s study wer e ver y effectiv e i nP

M emissio ncontrol . P M emission s fo r thes e scrubbe r type s range d fro

m 0.0 4 t o 0.1 3 lb/MMBt uan d average d0.0 7 lb/MMBtu . I nonl y on e o f th e 1 7 test s di d P M emission s excee d0.1 0 lb/MMBtu . Th e dat a indicat e tha t ventur i actio nan d hig hpressur e spray s wer e key contributor s t o th e lo w P M emissio nlevels . Wit hth e additio no f caustic , S0 2 emission s wer e als o effectivel y

controlled . Thi s performanc e wa s attaine dfo r scrubber s installe d onboiler s rangin g i nsiz e fro m 2 2 t o 25 0 MMBtu/hou r an dfue l sulfu r content s o f 1. 1 t o 2. 8 weigh t percent .



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