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# OAR Box 1107 Prepped by Ollie Stewart



### Document

Number: 

# 45 ) IV-E- 1 Docket Number: 

# A-81-2 1

Printed 4/11/2008 3:03:46

PM Sheet 45 of 90P. 2

p-7 * ' 

# A-81-2 1

CORPORATIO N IV-E- 1

MEMORANDUM DATE : Decembe r 21 , 198 4 TO : W . Fre dDimmick , Standard s Developmen t Branc h FROM : Kare nK . Fidler , Radia n SUBJECT : Meetin g Repor t - Incinerato r Bypas s Discussio nWit hVist a

Chemica l Compan y

Representative s
I . Purpos e Representative s o f Vist a Chemica l Company provide dinformatio non incinerato r operation s an d incinerato r bypas s occurrence s a t thei r ethylen e dichloride/viny l chlorid e (EDC/VC ) plan t i n Westlake , Louisiana . Thi s informatio nwil l b e use dt o stud y th e nee dfo r a contro l devic e bypas s provisio nfo r th e V C standard . Th e purpos e o f th e meetin g wa s t o gai n familiarit y

wit hEDC/V C proces s incineratio nsystem desig nan

d operations . II . Plac e an d Dat e U.S . Environmenta l Protectio nAgenc y Nort hCarolin a Mutua l Buildin g Durham , Nort hCarolin a Decembe r 12 , 198 4 III . Attendee s Fre dDin-mick , EPA/OAQPS/ESED/SD B Lesli e Evans , EPA/OAQPS/ESED/CP B Bo bRosensteel , EPA/OAQPS/ESED/CP B Susa nWyatt , EPA/OAQPS/ESED/CP B Kare nFidler , Radia nCorporatio n Jef f Shumaker , Radia nCorporatio n Ro nBryan , Chie f Proces s Engineer , Vist a Chemica l Company Jo e Ledvina , Director , Environmenta l Activities , Vist a Chemica l Company IV . Discussio n Prio r t o th e meeting , EP A provide dth e Vist a representative s wit ha lis t o f informatio nneed s t o serve a s th e basi s fo r th e meetin g discussion . (Se e lette r from

Evans , L . t o Ledvina , J. , Decembe r 5 , 1984 , Docke t No . ). . Vista' s respons e t o eac ho f th e identifie ddiscussio nitem s i s summarize dbelow .

Progres s Center/320 0 E

. Chape l Hil l Rd./Nelso n Hwy./P.O

. Bo x13000/Researc h Triangl e Park , N.C

. 27709/(919)541-910 0P. 3

Vist a bega nth e discussio nwit ha genera l descriptio no f thei r EDC/V C productio nfacilit y

i nWestlake , Louisiana . Attachmen t A i s a bloc k flow diagra m o f th e facility . I naddition , th e followin g genera l informatio nwa s provided :

- Th e Westlak e facilit y wa s previousl y

owne dan doperate db y Conoc o Chemicals . Sinc e mid-1984 , th e facilit y ha s bee nowne dand operate db

y Vist a wit hth e exceptio no f th e shi ploadin g doc k facilitie s whic har e lease dfrom Conoco .

- Th e ethylen e andchlorin e feedstock s fo r th e proces s ar e normall y obtaine dfrom

neighborin g Vist a andPP Gplants , respectively .

- ED C i s currentl y

produce db

y anoxygen-base d"balanced " proces s andi s use dprimaril y t o produc e VC a t th e Westlak e facility ; some ED C i s sold .

- Mos t o f th e VC produce da t thi s locatio ni s transferre dvi a rai l t o othe r Vist a facilitie s wher e polyviny l chlorid e (PVC ) i s made ; th e remainde r i s sol dan dtransferre dvi a pipeline , railca r o r ship . Incineratio nSyste m

Desig nandOperatio n A primar y anda secondar y

incineratio nsystem , eac hconsistin g o f a JohnZin k incinerator , wast e hea t boiler , HC l absorbe r andcausti c scrubber , wer e installe di n197 8 t o reduc e V C emission s i nexhaus t gase s t o 1 0 ppm . Th e two system s ar e virtuall y identica l excep t fo r some constructio n materials . Eac hsyste m i s capabl e o f handlin g th e ven t gase s generate d unde r norma l proces s operatin g condition s whil e operatin g a t abou t 5 0 percen t o f th e desig nhea t inpu t capacity . Thi s leave s abou t 5 0 percen t o f th e capacit y o f th e operatin g incinerato r availabl e t o handl e ven t ga s surges . Periodically , liqui dend s from th e ED C purificatio nproces s ar e burne dalon g wit hven t gase s i nth e incinerator . No significan t operatin g problem s ar e normall y encountere dwhil e burnin g liquids . Liquid s ar e no t being.burne d currently . Th e secondar y syste m serve s a s a backu pandi s operate donl y whe nth e primar y

syste m i s dow nfo r maintenance , o r i nparalle l wit hth e primar y incinerato r durin g plan t startup s andshutdown s an ddurin g occasiona l shi ploading . Desig nan doperatin g parameter s fo r eac hincinerato r includ e th e following :

- Hea t inpu t rat e (ven t ga s an dnatura l ga s combined ) desig ncapacit y

- 4 8 x1 0 g Btu/h r norma l operatio n- 2 5 x1 0 Btu/h rP. 4

- Temperatur e adiabati c - 1600° C operatin g - 1315° C standby - 600° C

- Firebo xpressur e maximu m desig n- 70 - 8 0 in . H„ 0 gaug e norma l operatio n- 20 - 3 0 in . H- 0 gaug e

- Ven t ga s nomina l flow

rat e - 40,00 0 scf h(^11,00 0 scf hfrom th e direc t chlorinatio nvent , 23,00 0 scf hfro m th e ligh t end s colum n vent ) nomina l hea t conten t - 7,00 0 Btu/l b

- Nat u ra l ga s norma l rang e - inpu t • 2. 4 - - 5 

### 1 2 X X 

### IO 6 Btu/h r Btu/h r

- Steam productio n norma l rat e - 16,00 0 - 20,00 0 lb/h r (35 0 psi )

- Maintenanc e annua l cos t - $500,00 0
s Incinerato r temperatur e i s controlle db y a wate r quenc hsystem consistin g o f si xnozzle s sprayin g stea m condensat e int o th e combustio n chamber . Th e primar y contro l paramete r fo r th e combustio nai r flow t o th e incinerato r i s th e rat e o f steam produce db

y th e wast e hea t boiler . I n addition , ther e i s an0 2 monito r inth e flu e ga s a s a tri m control . Th e natura l ga s inpu t t o th e incinerato r i s adjuste dmanuall y a s needed . Turndow ncapabilit y

canhandl e an

y ven t flow ; lo

w ven t ga s flow s ar e accommodate db

y increase dnatura l ga s usage . Th e secondar y

(o r standby ) incinerato r i s maintaine da t 600°C . At tha t temperature , i t ca nb e heate dupandbrough t on-lin e in1 0 minutes . Pas t operatin g experienc e indicate s tha t a 900° C standb y temperatur e allow s th e incinerato r t o b e heate du pin5 minutes . A

"col dstart " require s 2 5 hours . Approximatel y two-third s ( 8 - 9 x1 0 Btu/hr ) o f th e natura l ga s requiremen t fo r bot hincinerator s i s use d t o maintai nth e secondary ' incinerato r onho t standby . Some stea m i s generate db

y th e secondar y incineratio nsystem

whil e o

nstandby . I nth e even t th e primar y incinerato r trip s andcanno t b e restarted , vent s are

switche dmanuall y

(fro m th e contro l room ) t o th e secondar y system . A t leas t 1 0 minute s ar e require dt o switc hth e ven t gase s t o th e secondar y system . Usually , switchin g take s plac e i nles s tha n3 0 minutes . A planne d switc ht o th e secondar y incinerato r fo r schedule dmaintenanc e o f th e primar y system canb e performe dwithou t ventin g t o th e atmosphere .P. 5

Incinerato r Bypasse s A s show ni nAttachmen t A , al l vent s containin g VC i nth e Westlak e facilit y ar e ducte dt o th e incineratio nsystem wit hth e exceptio no f th e relie f valv e header . Othe r equipmen t vente dt o th e incineratio nsystem no t show ni nAttachmen t A

includ e pumps , agitato r seals , andED C intermediat e andfina l produc t storag e tanks . Th e VC-containin g vent s ar e separate dint o two ven t headers , th e dr y ven t heade r an

dth e we t ven t heade r (se e Attach men t B) . Bot hheader s ar e equippe dwit hautomati c pressur e contro l valve s whic hdiver t a portio no r al l o f th e ven t gase s awa y fro m th e incineratio n system whe nnecessar y

t o anemergenc y

ven t scrubber . Proces s Upset s Pressur e surge s cause db y a variet y

o f proces s upset s ar e detecte db y pressur e sensor s upstream an ddownstrea m

o f th e incinerator , whic hactivat e th e bypas s contro l valves . Incinerato r bypasse s typicall y hav e bee ncause d b y th e followin g althoug hothe r cause s hav e bee nnoted :

Ethan e contaminatio no f th e ethylen e feedstoc k andai r contamina tio no f th e chlorin e feedstoc k causin g hig hvolum e o f vent s i n direc t chlorinatio nheader , Hig hconcentratio no f contaminant s i nth e crud e ED C produc t causin g highinert s o r ligh t end s ven t volum e inligh t end s colum n vent , and Manua l ventin g durin g equipmen t purgin g operations . Incinerato r bypasse s cause db y feedstoc k contaminatio nar e no t readil y predictabl e b

y th e EDC/VC plan t sinc e thes e material s ar e obtaine dfro m outsid e o f th e plant . Vist a ha s implemente dprocedure s t o minimiz e incinera to r bypasse s durin g equipmen t purgin g operation s suc ha s placin g restriction s onmanua l vent s andstressin g operato r communication s durin g manua l equipmen t purging . Operato r error s causin g incinerato r bypasse s ar e treate dsimilarl y t o safet y

incidents . A

ninvestigatio no f th e caus e o f th e bypas s i s conducte d t o stres s th e seriousnes s o f thei r occurrenc e an dth e importanc e o f preventiv e measures . Thi s i s intende dt o provid e th e mai nplan t operator s wit hincentiv e t o notif y

andwor k wit hth e incinerato r operator s prio r t o ventin g s o tha t ven t ga s surge s ca nb e accommodated . Incinerato r Malfunction s Attachmen t C present s a complet e lis t o f condition s tha t resul t in automati c shutdow

no f th e incinerato r an dsubsequen t bypassin g o f ven t gases . Whe nautomati c shutdow no f th e incinerato r occurs , Vista' s procedur e i s t o identif y

th e caus e o f th e shutdow nan dt o attemp t t o restar t th e incinerato r unles s maintenanc e i s neede dt o repai r th e incinerator . Fo r instance , whe na hightemperatur e tri poccurs , th e incinerato r ca nb eP. 6

restarte dafte r th e fue l conten t o f th e ven t stream i s corrected . Tempera tur e senso r failure , however , woul drequir e repai r an d vent s woul dprobabl y b e switche dt o th e secondar y incineratio nsystem . I n mos t cases , attempt s t o restar t th e primar y incinerato r ar e successfu l withi n2 minutes . Conse quently , wit hany

give nshutdow

nincident , th e operato r mus t mak e a judgmen t a s t o whethe r th e 1 0 minut e heat-u pprocedur e fo r th e secondar y incinerato r o r th e restar t procedur e fo r th e primar y incinerato r i s th e mos t appropriat e actio nt o b e take nt o minimiz e th e bypas s duration . Inaddition , th e primar y incinerato r occasionall y require s shutdow

nfo r maintenanc e t o alleviat e burne r pluggin g problem s an d leakag e aroun dwate r quenc hnozzles . Becaus e burne r pluggin g an d quenc hnozzl e leak s ar e usuall y detectable , a planne dswitc hfro m th e primar y

t o th e secondar y

incineratio n system ca n b e performe dwithou t a bypass . Inorde r t o minimiz e ven t ga s bypasse s du e t o incinerato r malfunctions , Durin g maintenanc e periods , th e secondar y incineratio nsystem i s brough t on-lin e t o handl e al l o f th e ven t gases . Maintenanc e o f th e secondar y system occur s on an as-neede dbasi s throughou t th e year . I f possible , al l incinerato r maintenanc e occur s durin g n<»riods othe r tha nth e annua l plan t turnaround . Othe r method s hav e bee ninvestigate d fo r minimizin g bypasse s du e t o pressur e surge s an

d incinerato r trips . Fo r example , constructio no f a gasholde r t o b e use da s a ven t ga s surg e tank ha s bee nconsidered . However , i t wa s determine dtha t containmen t o f a typica l ven t stream fo r a 1 0 minut e perio dwoul drequir e a 4 0 foo t diamete r vesse l constructe do f exoti c material . Also , ther e ar e safet y considerations . O

n thi s basis , th e alternativ e wa s determine dt o b e unjustifiable . Metho dfo r Estimatin g V C Emission s Durin g Bypasse s Th e amoun t o f V C discharge dt o th e atmospher e durin g incinerato r bypasse s i s currentl y estimate db

y Vist a fo r reportin g purposes . (Earlie r thi s year , Louisian a bega nrequirin g V C plant s t o repor t bypas s incident s an dassociate dV

C emission s on a quarterl y basis. ) Bypasse s ar e detecte db y flowmeters downstream o f th e contro l valv e whic hrecor dth e duratio no f th e bypass . Estimate s o f V C emission s durin g bypasse s ar e base d on th e following : Result s o f a genera l materia l balanc e (update d periodicall y b y th e proces s engineerin g group ) o n th e dry

an d we t ven t header s assumin g desig ncapacit y

ratioe dfo r actua l production , Whethe r a ful l o r partia l bypas s occurred , an d Bypas s duration

.P. 7

V C Monitorin g V C monitorin g point s ar e locate di nth e incinerato r stac k a s par t o f th e multipoin t V

C monitorin g system

operate dinth e plant . Becaus e th e curren t multipoin t monitorin g system i s no t capabl e o f operatin g ove r th e wid e rang e o f V

C concentration s an

doperatin g condition s likel y t o occu r in th e incinerato r bypas s streams , thes e stream s ar e no t monitored . Impac t o f Oxychlorinatio nVen t Conversio no f th e ED C productio nproces s i n198 3 fro m anair-base dt o a noxygen-base dproces s resulte dineliminatio no f th e oxychlorinatio nvent . (Currently , roughl y

abou t 6,00 0 lb/h r o f purg e gase s from th e oxychlorinatio n reacto r containin g 8 5 percen t ethylen e an d1 5 percen t inert s ar e vente dt o th e direc t chlorinatio nreacto r wher e th e ethylen e i s reacted ; th e direc t chlorination.reacto r vent s t o th e incinerator. ) Consequently , al l VC containin g exhaus t gase s i nth e Westlak e facilit y ar e require d t o mee t th e 1 0 pp m standard s o f th e V

C standard . Th e inert s fro m th e oxychlorinatio n ven t stream

compris e abou t 4 0 t o 5 0 percen t o f th e direc t chlorination ' reacto r vent . V C Emission s Durin g Startup/Shutdow n Vista' s plan t startup/shutdow nprocedure s normall y requir e bot h incinerator s t o b e on-lin e throughou t th e startup/shutdow nsequence . Thi s procedur e significantl y reduce s th e ris k o f bypasse s durin g startup/shutdow n operations . Incinerato r Bypas s Histor y Attachmen t D summarize s th e bypas s histor y fo r th e Vista/Westlak e facilit y fo r th e perio dJanuar y throug hNovembe r 1984 . Th e percen t bypas s time give ninAttachmen t D refer s t o th e percentag e o f plan t operatin g hour s (i.e. , excludin g plan t turnarounds ) tha t partia l o r complet e bypasse s occurred . I naddition , th e followin g informatio nonbypas s duration s wa s provide d fo r th e perio dJanuar y throug hNovembe r 1984 . Sixt y percen t o f bypas s incident s las t les s tha n1 0 minutes , an d th e majorit y

o f thes e ar e 2 t o 5 minute s induration . Twenty-on e percen t o f bypas s incident s las t 1 0 t o 3 0 minutes . Thes e incident s generall y requir e switchin g t o th e secondar y incinerator . Twenty-on e percen t o f bypas s incident s wer e 3 0 minute s o r longe r induration . Th e majorit y o f thes e bypasse s wer e du e t o mechanica l failure s o r powe r outage s whic hprevente doperatio no f eithe r incineratio nsystem .Key

a ) o

+• > •x. —Continuou s Ven t

—Intermitten t Ven t

Chlorin e Ethylene • , Direc t Chlorinatio n Ven t Direc t Chlorinatio n ED C 

# TT

Ox yVen t Purg e Ga s

Oxyge n - Ethylene . Oxychlor

inatio n Ven t i Ligh t End s Colum n Ven t Ven t
ED C Washin g ED C Purifica

tio n

Steam Strippe r Wate r t o

Effluen t Treatmen t ED C Ligh t

End s _SJtor.ag

e

Pur e ED C

Uncracke d Recycl e ED C 

# u ED C Crackin g Viny l

Purificatio n Viny l

Chlorid e

HC l Ox y Shutdow n Vent s Relie f Valve s Ven t Scrubbe r Mai n Plan t Ven t Stac k
Note : *A1 1 doc k facilitie s owned an d operate d b

y Conoc o Inc . tlncineration 1 System

I Non-poin t sourc e I emissions , Manua l I ventin g Incinerato r Ven t Stac k

Shi p Loading 

# 1 Railca r Loadin g Carbo n Be d
Shi p Ven t Doc k Ven t Stack *

Pipelin e Ven t Recovery System
VIST ACHEMICAL CO . VCM PLAN

T FLO W DIAGRA

M AN D VEN T IDENTIFICATIO

N R B 11-30-8 4

### VC M PLAN T VENT HEADE R SYSTE M

C D C a > E

r— • o 

### VC M

Recover y Syste m Ven t

DryVents .

Tank Farm Ven t

We t Vent s DryVen t K O Po t

We t Ven t K O Po t

Relie f Valve . Heade r Relie f Valv e K O Po t ""*" " Incinerator s

~s Incinerato r

Ven t Stac k

Mai n Plan t Ven t Stac k

Ven t Scrubbe r

RB 11-30-8 4P.1 0

Attachmen t C

VII . Shutdow

n System Th e burne r managemen t syste mcontain s interlock s whic h automaticall y shutdow n th e incinerator
. Th e condition s whic h activat e shutdow n are : 1 . Hig h firebo x temperatur e (1,590°C ) sense d b ybot h temperatur e switches , TSDH-901 Aan d TSDH-901B . 2 . Lo w stea

mdru mleve l (2'-2" ) sense d b ybot h leve l switches , LSDL-905 Aan

d LSDL-905B . 3 . Hig h ga s temperatur e i n th e HC l absorbe r sense d b ybot h TSDH-90 8 (120°C ) an d TI-90 7 (230°C) . 4 . Lo w primar ycombustio n ai r flo w rat e (2,00 0 SCFM ) sense d bybot h flo w switches , FSDL-926 Aan d FSDL-926B . a . Lo w standb

yai r flo w rat e (20 0 SCFM ) sense d b yflo w switch , FSDL-945 . 5 . Flam e ou t sense d b ybot h mai n flam e scanners , XI-901 Aan d XI-901B . "6 . Flam e scanne r failur e sense d b ybot h mai n flam e scanners . 7 . Manua l shutdow

n a t th e mai n contro l panel . 8 . Manua l shutdow

n a t th e burne r managemen t panel . 9 . Powe r outage s o f mor e tha n 3 seconds . 10 . Hig h temperatur e o r leve l (.low) , i n th e flam e arrestor . Th e shutdow

n conditio n tha t cause d shutdow n i s identifie d b

ya flash

ing ligh t o n th e mai n contro l roomannunciato r panel . Prio r t o reachin g an

yo f th e automati c shutdowns , warnin g alarm s an d light s ar e indicate d o n th e mai n contro l boar d annunciato r pane l an d o n th e burne r managemen t panel . Warnin g alarm s an d shutdow

n condition s ar e discusse d furthe r i n Sectio n VII.B . A . Shutdow

n Sequenc e Wheneve r th e incinerato r shut s down , th e following action s occu r automatically
. 1 . Natura l ga s bloc k an d blee d valves , SSOV-906A.B , an d C , ar e de-energize d whic h force s th e valve s t o thei r failur e posi

tion s (bloc k valves- > closed , blee d valve- > open) .

10 6 -

### VISTACHEMICA L VC M PLANT INCINERATO R BYPAS S HISTORY (1 ) p. n
/•.ttaclimoirt

J



### Caus e Hig h Ven t Pressur e Flame-Ou t Mechanica l Failure s
Powe r Failur e
TOTA L No . O f Bypasse s 2 2
1 3

4
4 8 Bypas s

Hour s 

### 5. 5 4. 2 1. 8 3. 1
14. 6 % Bypas s

Tim e .06 5
.05 0
.02 0
.03 6
.17 1 Avg . Lbs .

Pe r Bypas s 

### 6. 0 8. 2 5. 0
20. 0



### Note ; Th e abov e dat a i s fo r illustrativ e purpose s onl yan d ma yno t necessaril y reflec t futur e operation
. (1 ) Dat a bas e perio d Jan . - Nov . 1984 .