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# OAR Box 1392 Prepped byOllie Stewart



### Document

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# 127 ) ll-A- 2 Docket Number: 

# A-94-5 2

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# LOCATINGAN

D ESTIMATING AIR#ilSSIpN S FROM SOURCES OFSTYRENE , INTERIM REPORT P. 2 

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### EPA-450/4-91-02 9 Octobe r199 1



### LOCATIN G AN D ESTIMATIN G AI R EMISSION S FRO M SOURCE S O FSTYRENE , INTERI M REPOR T

B y Darc yCampbel l Radia n Corporatio n Researc h Triangl e Park, Nort h Carolin a Contrac tNumbe r68-DO-0125

EP AProjec tOfficer : Ann e A . Pop

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U . S . ENVIRONMENTA L PROTECTIO N AGENC Y Offic e OfAi ran d Radiatio n Offic e O fAi rQualityPlannin g An d Standard s Researc h Triangl e Park , Nort h Carolin a 2771 1 

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## EP A 450/4-91-029

nP. 5

PREFAC E Thi s versio n o f th e "Locating and Estimatin g Ai r Emission s fromSource s o f Styrene " i s bein g publishe d a s a n Interi m Repor t pending incorporatio n o f testin g result s fromth e U.S . Environmenta l Protectio n Agenc y(EPA) . Th e EP Ai s currentl y testin g severa l unsaturate d polyeste r resi nfabricator s wh o produc e culture d marbl e bathroomfixtures . Whe n th e tes t result s ar e available , th e EPAwill , publis ha fina l repor t including thi s data . Unti l tha t time , however , al l o f th e informatio ncontaine d i n thi s documen t i s availabl e t o Federal , State , an d loca l ai r pollutio n personne l wh o ar e intereste d i n locatin g othe r potentia l source s o f styren e and estimatin g ai r emissions .

11 1

i • imjm n*B!**!m* JP. 6

TABL E O F CONTENT S Sectio n Pag e PREFAC E ii i 1 Purpos e o f Documen t 1

Reference s fo r Sectio n 1 4 2 Overvie wo f Documen t Content s 5 3 Background 7

Natur e o f Pollutan t 7 Overvie wo f Productio nand Us e 9 Reference s fo r Sectio n3 2 0 4 Emission s fromStyren e Productio n 2 3

Proces s Descriptio n 2 3 Emission s 3 2 Reference s fo r Sectio n4 . 4 1 5 Emission s fromMajo r Use s o f Styren e 4 3

Polystyren e Productio n 4 3 Styrene-Butadien e Copolyme r Productio n5 4 Styrene-Acrylonitril e Productio n 6 5 Acrylonitrile-Butadiene-Styren e Copolyme r Productio n 7 3 Unsaturate d Polyeste r Resi nProductio n8 2 Miscellaneou s Styren e Copolyme r Productio n... . 9 1 Reference s fo r Sectio n5 . 9 4 6 Emission s fromth e Us e o f Styrene-Containin g Material s . 9 7

Thermodegradatio n o f Styrene-Containin g Material s . 9 9 Acrylonitrile-Butadiene-Styren e Compoundin g ... . 10 1 Unsaturate d Polyeste r Resi nUs e 10 9

## " " l

TABL E O F CONTENT S (Continued ) Sectio n Pag e

Polystyren e Foa

m. . . 12 9 Reference s fo r Sectio n 6 14 0 7 Sourc e Tes t Procedure s 14 3

EPAReferenc e Metho d 1 8 14 3 NIOS H Metho d 150 1 . 14 5 EPAMetho d 504 0 14 6 Compendiu

m Metho d TO-1 4 14 7 EPAReferenc e Metho d 827 0 14 9 Reference s fo r Sectio n 7 ..-.- . 15 0

A

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LIS T O F TABLE S Tabl e Pag e 1 Chemica l and Physica l Propertie s o f Styren e 8 2 End-Use s o f Styren e 1 2 3 Potentia l Sourc e Categorie s o f Styren e Emission s ... . 1 3 4 Styren e Productio n Location s and Capacitie s 2 4 5 Styren e Storag e and Secondar yEmissio nFactor s 3 4 6 Averag e Emissio n Factor s fo r Fugitiv e Emission s ... . 3 6 7 Contro l Technique s and Efficiencie s Applicabl e t o Equipmen t Lea k Emission s 3 8 8 Polystyren e Productio nFacilitie s . . 4 5 9 Emissio n Factor s fo r Polystyren e Productio n5 5 1 0 Styrene-Butadien e Elastome r Productio nFacilitie s .. . 5 7 1 1 Styrene-Butadien e Late xProductio nFacilitie s 5 8 1 2 Typica l Recip e fo r Emulsio nSBR6 1 1 3 Emissio n Factor s fo r Styrene-Butadien e Productio n.. . 6 6 1 4 Styrene-Acrylonitril e Productio n Facilitie s ..... . 6 7 1 5 Acrylonitrile-Butadiene-Styren e Productio n Facilitie s 7 5 1 6 Typica l Component s Use d t o Form Unsaturate d Polyeste r Resin s 8 3 1 7 Producer s o f Unsaturate d Polyeste r Resin s 8 6 1 8 Emissio n Factor s fo r Styren e from UP RProductio n... . 9 0 1 9 Miscellaneou s Use s fo r Styren e i n Chemica l Productio n. 9 2 2 0 Prevalenc e o f Styreni c Resi nFabricator s 9 8 2 1 Styren e Emitte d from Thermobxidativ e Degradatio n... . 10 0 2 2 Summar yo f Sourc e Testin g Dat a fo r a n AB S Compoun d Facilit yUncontrolle d and wit hTemporaryControl s . . . 10 5 2 3 Summar yo f AB S Compoundin g Facilit ySourc e Tes t Dat a Afte r Installatio n o f Permanen t Control s ... . 10 8



### v n

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LIS T O F TABLE S (Continued ) Tabl e Pag e 2 4 Geographi c Distributio n o f Fiberglas s Boa t Industry byNumbe r o f Facilitie s . 11 9 2 5 VO C Emissio n Factor s fo r Polyeste r Resi nProduc t Fabricatio n Processe s .. . 12 4 2 6 Monomer-Base d Emissio nFactor s fo r Polyeste r Resin/Fiberglas s Operation s 12 5 2 7 Factor s Affectin g Styren e Emission s fromLaminatio n. . 12 8 2 8 Domesti c Consumptio n o f Polystyren e Foam byEnd Use s . . 13 1 2 9 Distributio n o f PS F Producer s b yStat e 13 2

Vil lP.1 0

LIS T O F FIGURE S Figur e Pag e 1 Chemica l Us e Tre e fo r Styren e 1 1 2 Location s o f Plant s Manufacturin g Styren e 2 5 3 Proces s Flo wDiagram fo r Styren e Productio nby Ethylbenzen e Dehydrogenatio n 2 7 4 Proces s Flo wDiagramfo r Styren e Productio nby Ethylbenzen e Hydroperoxidatio n . . 2 9 5 Proces s Flo wDiagram fo r Styren e Productio n by Isotherma l Processin g 3 1 6 Polystyren e Productio nb ySuspensio nPolymerizatio n. . 4 9 7 Polystyren e Productio n b yMas s Polymerizatio n5 0 8 Polystyren e Productio n bySolutio nPolymerizatio n.. . 5 2 9 S-B/SBRProductio n byEmulsio nPolymerizatio n5 9 1 0 SB RProductio n b ySolutio n Polymerizatio n. 6 3 1 1 Productio n o f SA NbyEmulsio n Polymerizatio n6 9 1 2 Productio n o f SA NbySuspensio n Polymerizatio n 7 1 1 3 Productio n o f SA NbyContinuou s Mas s Polymerizatio n . . 7 2 1 4 Productio n o f ABS/SA Nb yEmulsio n Polymerizatio n ... . 7 7 1 5 Productio n o f AB S b ySuspensio nPolymerizatio n7 9 1 6 Productio n o f AB S byContinuou s Mas s Polymerizatio n . . 8 1 1 7 Typica l Reaction s fo r Unsaturate d Polyeste r and Polyeste r Resi n Formatio n. . 8 5 1 8 Unsaturate d Polyeste r Resi nProductio n8 9 1 9 Origina l Vacuu

mand Ven t Systema t a nAB S Compounding Facilit y10 2 2 0 Permanen t VO C Control s a t a n AB S Compoundin g Facilit y. 10 7 2 1 Typica l Filamen t Windin g Proces s 11 3 2 2 Typica l Continuou s Laminatio n Productio nProces s ... . 11 5 2 3 Geographi c Distributio n o f Fiberglas s Boa t Manufacturin g Facilitie s fo r State s wit hMor e tha n Te n Facilitie s . . 12 1

I XP.1 1

LIS T O F FIGURE S (Continued ) Figur e Pag e 2 4 Fiberglas s Boa t Productio nProces s . 12 2 2 5 Flo wDiagramo f Typica l Polystyren e FoamShee t Manufacturin g Proces s . . 13 3 2 6 Flo wDiagram

o f a Typica l Polystyren e FoamBoar d Manufacturin g Proces s 13 6 2 7 Flo wDiagramo f a Typica l EP S Bea d Proces s . . • 13 7 2 8 Integrate d Ba g Sampling Trai n 14 4 2 9 Schemati c Diagramo f Tra p Desorption/Analysi s Syste m. . 14 7



### xP.1 2

SECTION1 PURPOS E O F DOCUMENT Th e Environmenta l Protectio nAgenc y(EPA ) and Stat e and loca l ai r pollutio n contro l agencie s ar e becomin g increasingl y awar e o f th e presenc e o f substance s i nth e ambien t ai r tha t may b e toxi c a t certai n concentrations . Thi s awareness , i nturn , ha s le d t o attempt s t o identif ysource/recepto r relationship s fo r thes e substance s and t o develo p contro l program s t o regulat e emissions . Unfortunately , verylittl e informatio ni s availabl e o n th e ambien t ai r concentration s o f thes e substance s o r o nth e source s tha t ma yb e dischargin g themt o th e atmosphere . T o assis t group s intereste d i ninventoryin g ai r emission s o f variou s potentiall ytoxi c substances , EP Ai s preparing a serie s o f document s suc ha s thi s tha t compile s availabl e informatio no n source s an

d emission s o f thes e substances . Prio r document s i n th e serie s ar e liste d below : Substanc e EPAPublicatio nNumbe r Acrylonitril e Carbo n Tetrachlorid e Chloroform Ethylen e Dichlorid e Formaldehyd e (Revised ) Nicke l Chromiu m Manganes e Phosgen e Epichlorohydri n Viny l Chlorid e Ethylen e Oxid e Chlorobenzene s Polychlorinate d Biphenyl s (PCBs ) « Polycycli c Organi c Matte r (POM ) Benzen e Organi c Liqui d Storag e Tank s Coa l and Oi l Combustio n Source s Municipa l Wast e Combustor s Perchloroethylen e and Trichloroethylen e EPA-450/4-84-007 a EPA-450/4-84-007 b EPA-450/4-84-007 C EPA-450/4-84-007 d EPA-450/2-91-01 2 EPA-450/4-84-007 f EPA-450/4-84-007 g EPA-450/4-84-007 h EPA-450/4-84-007 i EPA-450/4-84-007 J EPA-450/4-84-007 k EPA-450/4-84-007 1 EPA-450/4-84-007 m EPA-450/4-84-007 n EPA-450/4-84-007 p EPA-450/4-84-007 q EPA-450/4-88-00 4 EPA-450/2-89-00 1 EPA-450/2-89-00 6 EPA-450/2-90-01 3_EJ i

1,3-Butadien e Chromiu m(supplement ) Sewag e Sludg e EPA-450/2-89-02 1 EPA-450/2-89-00 2 EPA-450/2-90-00 9 Thi s documen t deal s specificall ywit hstyrene . It s intende d audienc e include s Federal , Stat e and loca l ai r pollutio n personne l and other s wh o ar e intereste d i nlocatin g potentia l emitter s o f styrene , and makin g gros s estimate s o f ai r emission s therefrom . Becaus e o f th e limite d amount s o f dat a availabl e o nsome potentia l source s b f styren e emissions , and sinc e th e configuration s o f manysource s wil l no t b e th e sam e a s thos e describe d here , thi s documen t i s bes t use d a s a prime r t o inform ai r pollutio n personne l abou t (1 ) th e type s o f source s "that ma y emi t styrene , (2 ) proces s variation s and releas e point s tha t may b e expecte d withi n thes e sources , and (3 ) availabl e emission s informatio n indicatin g th e potentia l fo r styren e t o b e release d int o th e ai r fromeac hoperation . Th e reade r i s strongl ycautione d agains t usin g th e emission s informatio n containe d i nthi s documen t t o tr yt o develo p a n exac t assessmen t o f emission s fromanyparticula r facility . Becaus e insufficien t dat a ar e availabl e t o develo p statistica l estimate s o f th e accurac yo f thes e emissio n factors , n o estimat e ca nb e mad e o f th e erro r tha t coul d resul t whe nthes e factor s ar e use d t o calculat e emission s fromanygive nfacility . I t i s possible , i n som e extreme cases , tha t order-of-magnitud e difference s coul d resul t betwee n actua l and calculate d emissions , dependin g o n difference s i n sourc e configurations , contro l equipment , an d operatin g practices . Thus , i nsituation s wher e a naccurat e assessmen t o f styren e emission s i s necessary , source-specifi c informatio n shoul d b e obtaine d t o confirmth e existenc e o f particula r emittin g operations , th e type s and effectivenes s o f contro l measures , and th e impac t o f operatin g practices . A sourc e tes t and/o r materia l balanc e shoul d b e considere d a s th e bes t mean s t o determin e ai r emission s directl yfroma n operation . I n additio n t o th e informatio npresente d i n thi s document , anothe r potentia l sourc e o f emission s dat a fo r styren e i s th e Toxi c Chemica l Releas e Inventory(TRI ) formrequire d bySectio n

IWflSWUiW W*W *P.1 4

31 3 o f Titl e II I o f th e Superfund Amendment s an d Reauthorizatio n Ac t o f 198 6 (SAR

A313). xSAR

A31 3 require s owner s and operator s o f certai n facilitie s tha t manufacture , import , proces s o r otherwis e us e certai n toxi c chemical s t o repor t annuall ythei r release s o f thes e chemical s t o anyenvironmenta l media . A s par t o f SAR A313 , EPAprovide s publi c acces s t o th e annua l emission s data . Th e TR I dat a includ e genera l facilit yinformation , chemica l information , an d emission s data . Ai r emission s dat a ar e reporte d a s tota l facilit yreleas e estimates , broke n ou t int o fugitiv e and poin t components . N o individua l proces s o r stac k dat a ar e provide d t o EPA . Th e TR I require s th e us e o f availabl e stac k monitorin g o r measuremen t o f emission s t o compl ywit hSAR A 313 . I f monitorin g dat a ar e unavailable , emission s ar e t o b e quantifie d base d o n bes t estimate s o f release s t o th e environment . Th e reade r i s cautione d tha t th e TR I wil l no t likel yprovid e facility , emissions , and chemica l releas e dat a sufficien t fo r conducting detaile d exposur e modelin g and ris k assessment . I n man ycases , th e TR I dat a ar e base d o n annua l estimate s o f emission s (i.e. , o n emissio n factors , materia l balances , engineering judgment) . Th e reade r i s urge d t o obtai n TR I dat a i n additio n t o informatio n provide d i nthi s documen t t o locat e potentia l emitter s o f styrene , and t o mak e preliminaryestimate s o f ai r emission s from thes e facilities . T o obtai n a nexac t assessmen t o f ai r emission s fromprocesse s a t a specifi c facility , sourc e test s o r detaile d materia l balanc e calculation s shoul d b e conducted , and detaile d plan t sit e informatio nshoul d b e compiled .P.1 5

REFERENCE S FORSECTION1

as e Reporting : •21208 . Jun e 4 , 1987 . 1 . Toxi c Chemica l Releas e Reporting : Communit yRight-To-Know . Federa l Registe r 52(107) : 21152-21208 . .Tnn o A iaaiP.1 6

SECTIO N2 OVERVIEWO F DOCUMEN T CONTENT S A s note d i n Sectio n 1 , th e purpos e o f thi s documen t i s t o assis t Federal , Stat e and loca l ai r pollutio nagencie s and other s wh o ar e intereste d i n locatin g potentia l ai r emitter s o f styren e and makin g gros s estimate s o f ai r emission s therefrom . Becaus e o f th e limite d background dat a available , th e informatio n summarize d i n thi s documen t doe s no t an d shoul d no t b e assume d t o represen t th e sourc e configuratio n o r emission s associate d wit h an yparticula r facility . Thi s sectio n provide s a novervie wo f th e content s o f thi s document . I t briefl youtline s th e nature , extent , and forma t o f th e materia l presente d i n th e remainin g section s o f thi s report .

. . Sectio n 3 o f thi s documen t briefl ysummarize s th e physica l and chemica l characteristic s o f styrene , an d provide s a novervie w o f it s productio n an d use . Thi s background sectio nma yb e usefu l t o someon e wh o need s t o develo p a genera l perspectiv e o nth e natur e o f thi s substanc e and ho wi t i s manufacture d and consumed . Section s 4 , 5 , an

d 6 o f thi s documen t focu s o nmajo r sourc e categorie s tha t maydischarg e styren e ai r emissions . Sectio n4 discusse s emission s fromth e productio no f styrene ; Sectio n5 discusse s emission s fromth e majo r use s o f styrene ; and Sectio n 6 addresse s emission s fromth e us e o f styrene-containing materials . Fo r eac hmajo r industria l sourc e categorydescribe d i n Section s 4 , 5 , and 6 , exampl e proces s description s and flo w diagram s ar e given , potentia l emissio n point s ar e identified , ari d availabl e emissio n facto r estimate s ar e presented.-that. , sho wth e potentia l fo r styren e emission s befor e an d after..control s ar e employe d byindustry . Individua l companie s ar e name d tha t ar e reporte d t o b e involve d wit heithe r th e productio no r us e o f styren e base d primaril yo ninformatio n fro mtrad e publications . Th e fina l sectio n o f thi s documen t summarize s availabl e procedure s fo r sourc e samplin g and analysi s o f styrene . Detail s ar e no t prescribe d no r i s an yEP Aendorsemen t give no r implie d t o

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anyo f thes e samplin g an d analysi s procedures . A t thi s time , EP A ha s no t generall yevaluate d thes e methods . Consequently , thi s documen t merel yprovide s a n overvie wo f applicabl e sourc e samplin g procedures , citin g reference s fo r thos e intereste d i n conductin g sourc e tests . Thi s documen t doe s no t contai n anydiscussio no f healt ho r othe r environmenta l effect s o f styrene , no r doe s i t includ e any discussio n o f ambien t ai r level s o r ambien t ai r monitorin g techniques . Comment s o n th e content s o r usefulnes s o f thi s documen t ar e welcomed , a s i s anyinformatio no nproces s descriptions , operatin g practices , contro l measure s an d emission s informatio n tha t woul d enabl e EP At o improv e it s contents . Al l comment s shoul d b e sen t to :

Chief , Emissio n Facto r and Methodologie s Sectio n Emissio n InventoryBranc h(MD-14 ) U . S . Environmenta l Protectio n Agenc y Researc hTriangl e Park , Nort hCarolin a 2771 1P.1 8

SECTION3 BACKGROUND NATUR E O F POLLUTANT Styren e (CAS No . 100-42-5 ) i s a n unsaturate d aromati c monome r tha t i s widel yuse d i n th e productio no f plastics , resins , and elastomers . I n th e pas t centuryproductio n an d us e o f styren e hav e increase d rapidl ybecaus e i t ca n b e polymerize d and copolymerize d easil yt o produc e a wid e variet yo f products . Styren e wa s th e twenty-firs t highest-volum e chemica l produce d i n th e Unite d State s i n 1988. 1 Styrene' s molecula r formul a i s represente d as : CH-CJ ^

Tabl e 1 show s th e chemica l and physica l propertie s o f styrene . Becaus e o f styrene' s flammabilit yand it s eas e o f polymerization , a n inhibito r (10-1 5 ppmtert-butylcatechol ) mus t b e adde d during storag e and hig htemperature s mus t b e avoided. 3 Styren e i s release d t o th e atmospher e durin g it s manufactur e an d fromth e us e o f styrene-containin g materials . Styren e ha s als o bee n detecte d i n smal l amount s i nautomobil e emissions 3 and frompublicl yowne d treatmen t works. 4 Th e combustio no f styrene base d product s i s anothe r potentia l sourc e o f styren e emissions. 8 Styren e i s veryreactiv e i nth e air , reactin g readil ywit h hydroxy l radical s an d ozone. 6 Styren e readil yundergoe s oxidatio n b

yozon e t o produc e formaldehyde , benzaldehyde , benzoi c acid , and trace s o f formi c acid . Th e styren e half-lif e resultingTABL E 1 . CHEMICAL AND PHYSICAL PROPERTIE S O F STYRENE P.1 9

Synonyms :

Chemica l Abstract s RegistryNumber : Molecula r Formula : Molecula r Weight : Ambien t state : Boilin g Point : (76 0 m m Hg ) Freezin g Point : Density : Solubility :

Flammabl e (explosive ) Limits : Flashpoint : Autoignitio n Temperature : Vapo r Pressure :

Concentratio n i n Saturate d Air : Odo r Threshold : Conversio n Factors : (25°C , 76 0 m

mHg ) Cinnamene , cinnamenol , cinnamol ,

ethenylbenzene , monotryrene , phenthylene , phenlethene , phylethylene , styrole , styrolene , styron , styropol , styropor , vinylbenzene , vinylbenzo l 100-42- 5 C 6 H 5 CH = CH 2 104.1 6 Colorles s volatil e liqui d 145.2° C (293.4"F ) -30.6° C (-23.1'F ) 0.901 8 g/cm 3(25°C ) Solubl e i n ethy l ether , benzene , methanol , toluene , ethanol , acetone , n-heptane , carbo n tetrachloride , carbo ndisulfide ; slightl ysolubl e i n wate r (abou t 2 5 mg/10 0 g wate r a t 25°C ) 1.1-6.1 % byvolum e i nai r 34.4° C (94°F ) Ta g close d cu p 36.7° C (98*F ) Ta g ope n cup 490° C (914°F ) 

# : z 5 0 6 8 7 7 8 6 10 4 

### CC) (10 ) (20 ) (25 ) (30 ) (40 ) m

m H g 2.3 4 4.5 0 6.4 5 8.2 1 14.3 0 fkPa )

(0.31 ) (0.60 ) (0.86 ) (1.09 ) (1.91 ) 8,50 0 ppm(25*C ) 0.0 5 - 0.1 5 ppm 1 ppm=4.2 6mg/m 3 1 mg/m 3= 0.23 5 ppm Source : Reference s 7 an d 8 .P.2 0

fromit s oxidatio n b yozon e i s estimate d t o b e a t leas t 9 hours. 6 Th e oxidatio n o f hydroxy l radical s yield s benzaldehyde . Th e estimate d half-lif e o f styren e fromthi s oxidatio ni s 3 hours. 6 Styren e release d t o wate r i s expecte d t o hav e a nevaporativ e half-lif e o f 23. 8 hours , assumin g a wate r dept ho f 1 mete r (3.2 8 feet) . I n addition , styren e ma yb e oxidize d b ysom e commo n wate r treatmen t compounds . Epichlorohydri ni s forme d i n th e presenc e o f styren e an

d aqueou s chlorin e (hypochlorou s acid). 3 Liqui d styren e expose d t o ai r result s i npolymerizatio no f styren e initiate d byozone . A s i t polymerizes , styren e become s increasingl yviscou s unti l . a clear , gloss ysoli d i s formed. ' OVERVIE WO F PRODUCTIONAND US E Th e tota l annua l capacit yo f styren e manufacturin g facilitie s i n th e Unite d State s wa s 4,075,14 2 M g (898 4 MMlbs ) i n 1989. 1 0 Th e majorit yo f styren e i s produce d b ydehydrogenatio n o f ethylbenzene , wit habou t 1 5 percen t produce d by hydroperoxidatio n o f ethylbenzene . Propylen e i s a coproduc t i n th e hydroperoxidatio n process . I n 1989 , eigh t companie s a t nin e location s produce d styren e i nth e Unite d States . On e additiona l facilit yha s bee n o n standb ysinc e 1985. 1 0 Th e ethylbenzen e use d t o manufactur e styren e i s produce d b yalkylatio no f benzen e o r extractio n frommixe d xylenes. 1 1 Mos t ethylbenzen e productio n processe s ar e fo r captiv e styren e use s rathe r tha nfo r sal e o f th e monomer. 1 0 •Styrene i s manufacture d a s a nintermediat e fo r th e productio n o f polystyren e (68%) , styrene-butadien e (SBR ) | elastomer s (6%) , latexe s (SB Rlatexe s containin g <45 % styren e an d | styrene-butadien e latexe s containin g >45 % styrene ) (7%) , ! acrylonitrile-butadien e styren e (ABS ) resin s and styrene acrylonitril e (SAN ) (9%) , unsaturate d polyeste r resin s (7%) , and j fo r miscellaneou s product s and expor t (3%). " Seve no f th e eigh t

styren e productio n facilitie s hav e som e captiv e consumptio no f styren e monomer . Captivel yconsume d monome r i s mainl yuse d fo r manufacturin g polystyrene , bu t i t i s als o use d t o a lesse r exten t t o produc e ABS , SAN , an d styrene-butadien e copolyme r latexes. 1 3 Figur e 1 and Tabl e 2 sho wsom e o f th e end product s fromstyrene .P.2 1 ^

Thes e product s and some o f thei r productio nprocesse s wil l b e covere d i n detai l i n Section s 5 and 6 . Tabl e 3 list s th e potentia l sourc e categorie s o f styren e emission s b yStandar d Industria l Classificatio n(SIC ) code . I t i s importan t t o not e tha t thes e sourc e categorie s dbno t necessaril ydenot e significan t source s o f styren e emissions .



### 1 0P.2 2



### Productio n Method Use Percen t

Ethylbenzen e Dehydrogenatlo n (85%)

Ethylbenzen e Hydroperoxidatio n (15%) Polystyren e Styren e butadien e (SBR) elastome r Styren e butadien e (SBR) latex(contain s <45 % styrene) an d styrene-butadien e latex(contain s >45 % styrene )

Unsaturate d polyeste rresin s Acrylonitrile-butadlene-styren e resin s an d styrene-acrylonttril e Miscellaneou s an d expor t 6 8 6

7 9



### Figur e 1 . Chemica l Use Tree fo rStyrene 1 2 100

1 1P.2 3

TABL E 2 . END USE S O F STYRENE Polystyren e

Styren e butadien e rubbe r (SBR ) elastomer s and latexe s Styrene-butadien e (S-B ) latexe s Acrylonitrile

butadiene-styren e (ABS )

Styrene

acrylonitril e (SAN ) Unsaturate d polyeste r resins(reinforce d plastics / composites ) Insulatio nboard , loose-fil l packaging , disposabl e dinnerware , foo d containers , toys , games , hobbykits , housing s fo r room ai r conditioner s and smal l handhel d appliances , televisio n cabinets , showe r doors , drai n pipes , tubing , ligh t diffusers , audi o and vide o tap e cassettes , combs , brushes , eyeglasses , picni c coolers , molde d shutters , furnitur e parts , watering cans , soa p dishes , roo mdivider s Passenge r ca r tires , industria l hoses , conveye r belts , applianc e parts , wir e an d cabl e insulation , footwear , coate d fabrics , ca r bumper s and weatherstrips , additiv e i n cement s an d adhesive s Tufte d carpe t and upholstery~ - backcoatings , binde r fo r pape r coatings , binde r fo r fel t bas e o f viny l floo r tile , cemen t additive , componen t o f late xpaint s Piping (drain , waste , and vent) , conduit , pipefittings , automotiv e component s (instrumen t panels , consoles , fron t radiato r grilles , headligh t housings , etc.) , refrigerato r doorliner s an d foo d compartments , telephones , luggag e and cases , toys , hobbykits , showe r stall s and bathroomfixture s fo r mobil e homes , margarin e rubs , radi o chassi s Drinking tumblers , blende r jar s an d covers , dishes , instrumen t pane l lenses , batterycase s Fiberglas s reinforce d boats , storag e tanks , tub , spa , an d showe r units , truc k campe r tops , recreationa l vehicles , wal l panels , culture d marbl e products , automotiv e parts , appliance/electrica l components , and man yothe r products . Source : Referenc e 8



### 1 2

•««*» .P.2 4

TABL E 3 . POTENTIAL SOURC E CATEGORIE S O F STYRENE EMISSION S SI C CODE " SOURC E DESCRIPTION 133 1 Crud e petroleu man d natura l ga s 132 1 Natura l ga s liquid s 171 1 Plumbing , heating , air-conditionin g 174 3 Terrazzo , tile , marble , mosai c wor k 222 1 Broadwove n fabri c mills , manmad e 226 2 Finishin g plants , manmad e 229 5 Coate d fabrics , no t rubberize d 243 1 Millwor k 243 4 Woo d kitche n cabinet s 249 2 Reconstitute d woo d product s 249 9 Woo d products , no t elsewher e classifie d 251 1 Woo d househol d furnitur e 251 7 Woo d TV

and radi o cabinet s 251 9 Househol d furnitur e no t elsewher e classifie d 252 2 Offic e furniture , excep t woo d 253 1 Publi c buildin g and relate d furnitur e 259 9 Furnitur e and fixtures , no t elsewher e classifie d 26 5 PAPE RAN D ALLIE D PRODUCT S 262 1 Pape r mill s 263 1 Paperboar d mill s 26 5 Paperboar d container s and boxe s 265 5 Fibe r cans , drums , and simila r product s 265 7 Foldin g paperboar d boxe s 26 7 Miscellaneou s converte d pape r product s 267 2 Paper , coate d and laminated , no t elsewher e classifie d 2 8 CHEMICAL S AN D ALLIE D PRODUCT S 28 1 Industria l gase s 281 2 Inorgani c pigment s 281 3 Industria l inorgani c chemicals , no t elsewher e

classifie d

1 3P.2 5

TABL E 3 . (Continued ) 281 6 Industria l pigment s 281 9 Industria l inorgani c chemicals , no t elsewher e

classifie d 28 2 Plastic s material s and synthetic s 282 1 Plastic s material s and resin s 282 3 Cellulosi c manmad e fiber s 283 3 Medicinal s an d botanical s 283 4 Pharmaceutica l preparation s 283 5 Diagnosti c substance s 283 6 Biologica l product s (excluding diagnostic ) 284 1 Soa p and othe r detergent s 284 2 Polishe s an d sanitatio ngood s 284 3 Surfac e activ e agent s 284 4 Toile t preparation s 285 1 Paint s and allie d product s 28 6 Industria l organi c chemical s 286 1 Gumand woo d chemical s 286 5 Cycli c crude s an d intermediate s 286 9 Industria l organi c chemicals , no t elsewher e

classifie d 287 3 Nitrogenou s fertilizer s 287 4 Phosphati c fertilizer s 287 9 Agricultura l chemicals , no t elsewher e classifie d 289 1 Adhesiv e and sealant s 289 2 Explosive s 289 9 Chemica l preparations , no t elsewher e classifie d 2 9 PETROLEUMAND COA L PRODUCT S 291 1 Petroleu

mrefining 295 1 Asphal t paving mixture s and block s 299 2 Lubricatin g oil s an d grease s 299 9 Petroleu

m an d coa l products , no t elsewher e classifie d

1 4P.2 6

TABL E 3 . (Continued ) 3 0 RUBBE RAN D MISCELLANEOU S PLASTIC S PRODUCT S 301 1 Tire s and inne r tube s 302 1 Rubbe r and plastic s footwar e 305 2 Rubbe r and plastic s hos e an d beltin g 306 9 Fabricate d rubbe r products , no t elsewher e classifie d 30 8 Miscellaneou s plastics'products , no t elsewher e

classifie d 308 1 Unsupporte d plastic s fil mand shee t 308 2 Unsupporte d plastic s profil e shape s 308 3 Laminate d plastic s plat e and shee t 308 4 Plastic s pip e 308 6 Plastic s foam product s 308 7 Custo mcompound purchase d resin s 308 8 Plasti c plumbin g fixture s 308 9 . Plastic s products,.no t elsewher e classifie d 314 2 Hous e slipper s 322 9 Presse d and blownglass , no t elsewher e classifie d 324 1 Cement , hydrauli c 326 1 Vitreou s plumbin g fixture s 327 1 Concret e bloc k and bric k 327 2 Concret e products , no t elsewher e classifie d 327 4 Lim e 328 1 Cu t ston e and ston e product s 329 1 Abrasiv e product s 32 9 Minera l woo l 329 9 Non-metalli c minera l products , no t elsewher e

classifie d 331 2 Blas t furnace s and stee l mill s 331 3 Electrometallurgica l product s 31 6 Col d finishing o f stee l shape s 332 1 Grayand ductil e iro n foundrie s 332 4 Stee l investmen t foundrie s



### 1 5P.2 7

TABL E 3 . (Continued ) 332 5 Stee l foundries , no t elsewher e classifie d 333 9 Primar ynonferrou s metals , no t elsewher e classifie d 334 1 Secondar ynonferrou s metal s 336 3 Aluminumdie-castin g 336 4 Nonferrou s die-casting , excludin g aluminu m 336 5 Aluminumfoundrie s 336 6 Coppe r foundrie s 336 9 Nonferrou s foundries , no t elsewher e classifie d 3 4 FABRICATEDMETA L PRODUCT S 342 3 Hand and edg e tools , no t elsewher e classifie d 34 3 Plumbin g and heating , excep t electri c - - - 343 1 Meta l sanitar ywar e 34 4 Fabricate d structura l meta l product s 344 1 Fabricate d structura l meta l 344 2 Meta l doors , sash , an d tri m 334 3 Fabricate d plat e wor k (boile r shops ) 344 4 Shee t meta l wor k 344 6 Architectura l meta l wor k 345 1 Scre wmachin e product s 347 9 Meta l coatin g an d allie d service s 349 8 Fabricate d pip e an d fitting s 349 9 Fabricate d meta l products , no t elsewher e classifie d 351 1 Turbine s and turbin e generato r set s 351 9 Interna l combustio nengines , no t elsewher e classifie d 35 2 Farman d garde n machinery 352 3 Farmmachiner yan d equipmen t 353 3 Oi l and ga s fiel d machinery 354 1 Machin e tools , meta l cuttin g type s 354 6 Power-drive n handtool s



### 1 6P.2 8

TABL E 3 . (Continued ) 354 8 Weldin g apparatu s 356 1 Pump s and pumpin g equipmen t 356 3 Ai r and ga s compressor s 356 4 Blower s and fan s 357 5 Compute r terminal s 358 5 Refrigeratio n and heatin g equipmen t 359 9 Industria l machinery , no t elsewher e classifie d 361 2 Transformers , excep t electroni c 361 3 Switchgea r and switchboar d apparatu s 362 1 Motor s and generator s 362 4 Carbo n and graphit e product s 362 5 Relay s and industria l control s 364 3 Current-carryin g wirin g device s 364 4 Noncurrent-carryin g wirin g device s 364 7 Vehicula r lighting equipmen t 366 1 Telephon e an d telegrap happaratu s 366 3 Radi o and T V communication s equipmen t 36 7 Electri c component s an d accessorie s 367 1 Electro n tube s 367 4 Semiconductor s and relate d device s 367 9 Electroni c components , no t elsewher e classifie d 369 4 Engin e electrica l equipmen t 3 7 TRANSPORTATIONEQUIPMENT ^37 1 Moto r vehicle s and equipmen t 371 1 Moto r vehicle s and ca r bodie s 371 3 Truc k and bu s bodie s 371 4 Moto r vehicle s part s and accessorie s 371 5 Truc k trailer s 371 6 Moto r home s



### 1 7P.2 9

TABL E 3 . (Continued )

A 372 1 Aircraf t

37 3 Shi p and boa t building and repairin g 373 1 Shi p buildin g an d repairin g 373 2 Boa t buildin g an d repairing 379 2 Trave l trailer s an d camper s 379 9 Transportatio n equipment , no t elsewher e classifie d 381 2 Searc hand navigatio nequipmen t 382 1 Laboratoryapparatu s and furnitur e 382 6 Analytica l instrument s 382 9 Measurin g and controlling devices , no t elsewher e

classifie d ~ ~ 384 2 Surgica l appliance s and supplie s 384 4 X-rayapparatu s an d tube s 386 1 Photographi c equipmen t and supplie s 3 9 MISCELLANEOU S MANUFACTURINGINDUSTRIE S 393 1 Musica l instrument s 39 4 Toy s and sporting good s 394 4 Games , toys , and children' s vehicle s 394 9 Sportin g an d athleti c goods , no t elsewher e classifie d 396 5 Fasteners , buttons , needles , and pin s 399 9 Manufacturin g industries , no t elsewher e classifie d 422 5 Genera l warehousing an d storag e 422 6 Specia l warehousing an d storage , no t elsewher e classifie d 423 1 Truckin g termina l facilitie s 499 1 Marin e carg o handling 461 2 Crud e petroleu mpipeline s 495 3 Refus e system s 496 1 Steamand air-conditioning suppl y 509 1 Sportin g an d recreationa l good s



### 1 8P.3 0

TABL E 3 . (Continued ) 51 6 Chemical s and allie d product s 517 1 Petroleu

mbul k station s and terminal s 651 2 Nonresidentia l buildin g operator s 651 4 Dwellin g operators , excludin g apartment s 738 9 Busines s services , no t elsewher e classifie d 799 9 Amusemen t and recreation , no t elsewher e classifie d 806 2 Genera l media l and surgica l hospital s 873 1 Commercia l physica l researc h 899 9 Services , no t elsewher e classifie d *SI C Cod e i s liste d a s a potentia l sourc e i nth e EP A"Crosswalk " document. 1 3 Th e dat a i n Crosswal k wer e obtaine d primaril yfrom permittin g and sourc e tes t informatio ncontaine d i n th e 198 6 Nationa l Ai r Toxic s Informatio nClearinghous e (NATICH ) dat a base . Additiona l dat a wer e gathere d fromth e Organi c Chemica l Producers ' Dat a Bas e and Ai r Emission s Specie s Dat a Manua l (Volume I , Volatil e Organi c Compound Specie s profiles) , and SAR A 31 3 Toxi c Releas e Inventory. 1 3

\



### 1 9P.3 1

REFERENCE S FORSECTION3 1 . Chemica l and Engineering News . Fact s and Figure s fo r th e Chemica l Industrya t a Glance , pp . 36-45 . Jun e 1989 . 2 . Nationa l Researc hCouncil . Th e Alky l Benzenes . Committe e o n Alky l Benzen e Derivatives ; Boar d o nToxicologyand Environmenta l Healt hHazards ; Assembl yo f Lif e Science . Nationa l Academ

yPress . 1981 . 3 . Santodonato , J. , e t al . Investigatio n o f Selecte d Potentia l Environmenta l Contaminants : Styrene , Ethylbenzene , an d Relate d "Compounds . EPA-560/11-80-018 . U . S . Environmenta l Protectio n Agency , Washington , D.C . 1980 . 4 . Pope , A . A. , e t al . Toxi c Ai r Pollutan t Emissio nFactor s - ACompilatio n fo r Selecte d Ai r Toxi c Compound s and Sources . EPA-450/2-88-006 . U . S . Environmenta l Protectio n Agency , Researc hTriangl e Park , Nort hCarolina . 1988 . 5 . Pfaffli , P. , e t al . Therma l Degradatio nProduct s o f Homopolyme r Polystyren e i nAir . Scand . J . Wor k Environ , and Health . Suppl . 2:22-27 . 1978 . 6 . Alexander , M . Th e Environmenta l Fate , o f Styrene . Th e SIR C Review , pp . 33-42 . Apri l 1990 . 7 . Kirk-Othme r Encyclopedi a o f Chemica l Technology . 3rd ed . Styrene . Volum e 21 . John Wile yan d Sons . Ne wYork , Ne w York . pp . 770-801 . 1983 . 8 . U . S . Departmen t o f Healt hand Huma nServices . Criteri a fo r a Recommende d Standard . Occupationa l Exposur e t o Styrene . DHH S (NIOSH ) Publicatio n No . 83-119 . Nationa l Institut e fo r Occupationa l Safet yand Health , Cincinnati , Ohio . 1983 . 9

- Lowenheim , F . A . an d M . K . Moran . Styrene . In : Faith , Keyes , an

d Clark' s Industria l Chemicals . JohnWile yand Sons . Ne wYork , Ne wYork . pp . 779-785 . 1975 . 10 . SR I International . 198 9 Director yo f Chemica l Producers , Unite d State s o f America . Menl o Park , California . 1989 . 11 . U . S . Environmenta l Protectio n Agency . Benzen e Emission s fromth e Ethylbenzene/Styren e Industry- Background Informatio n fo r Propose d Standards . EPA-450/3-70-035a . Researc hTriangl e Park , Nort hCarolina . 1980 . 12 . A . T . Kearney . Impac t Analysi s o f th e EPAOffic e o f Drinkin g Wate r Proposa l t o Regulat e Styrene . Styren e Informatio n Researc hCenter . 1989 .

2 0P.3 2

13 . Pope , A . A. , e t al . Toxi c Ai r Pollutant/Sourc e Crosswal k AScreening Too l fo r Locatin g Possibl e Source s Emitting Toxi c Ai r Pollutants , Second Edition . EPA-450/2-89-017 . U . S . Environmenta l Protectio nAgency , Researc hTriangl e Park , Nort hCarolina . 1989 .



### 2 1P.3 3

2 2P.3 4

SECTION4 EMISSION S FROMSTYREN E PRODUCTION Styren e productio n an d th e associate d ai r emission s ar e describe d i n thi s section . Proces s flo wdiagram s ar e include d a s appropriate , wit hspecifi c stream s o r vent s i n th e figure s labele d t o correspond wit hth e discussio ni n th e text . Emissio n factor s fo r th e productio nprocesse s ar e presente d whe n available , and contro l technologie s ar e described . Th e reade r shoul d contac t th e specifi c facilit yt o verif yth e natur e o f th e proces s used , productio n volume , and control s i n plac e befor e applyin g an

yo f th e emissio n factor s presented . Styren e i s currentl yproduce d byeigh t companie s a t nin e location s i n th e Unite d States . On e additiona l facilit yha s bee n o n standb

ysinc e 198 5 and i s no t currentl ymanufacturin g styrene . Th e productio n location s an d capacitie s ar e presente d i nTabl e 4 . Th e tota l annua l capacit yfo r al l styren e manufacturin g facilitie s i s 4,075,14 2 M g (898 4 M Mlbs ) (no t includin g th e plan t o n standby), 1 wit hfacilitie s operatin g a t 9 8 percen t o f capacity. 2 A s shown i n Figur e 2 , th e majorit yo f styrene manufacturin g facilitie s ar e locate d o nth e Gul f Coast . Al l bu t on e plan t manufacture s styren e b ydehydrogenatio n o f ethylbenzene . Th e othe r facilit yuse s hydroperoxidatio n o f ethylbenzen e t o produc e propylene , wit hstyren e a s a by-product . PROCES S DESCRIPTION Ethylbenzen e Dehydrogenatio n Th e majorit yo f styren e produce d i n th e Unite d State s i s produce d b

yth e dehydrogenatio n o f ethylbenzene . Seve n facilitie s hav e th e capacit yt o produc e a nannua l tota l o f 3,480,92 6 M g (767 4 MMlbs) .



### 2 3P.3 5

TABL E 4 . STYREN E PRODUCTIONLOCATION S AND CAPACITIE S

Facilit y Amoc o Corporatio n ARC O Chemica l Co . Chevro n Corporatio n Cos-Mar , Inc . Do wchemica l Huntsma n Chemica l Corp . Rexen e Product s Co . Sterlin g Chemicals , Inc . Locatio n Texa s City , T X Channelview , TX * Monaca , PA St . James , L A Carville , LA Freeport , T X Midland , MI b Bayport , T X Odessa , T X Texa s City , T X Annua l Capacit y Mg/y r 362,88 0 594,21 6 99,79 2 272,16 0 680,40 0 639,57 6 146,96 6 .453,60 0 145,15 2 680,40 0 4,075,14 2 MM

lb/yr 80 0 13i 0 22 0 60 0 150 0 141 0 32 4 100 0 32 0 150 0 898 4 "Ethylbenzen e hydroperoxidatio nprocess . "Plan t ha s bee n o n standb ysinc e 198 5 (no t include d i ntota l capacity) . NOTE : Thi s listing i s subjec t t o chang e a s marke t condition s change , facilit yownershi p changes , plant s ar e close d down , etc . Th e reade r shoul d verif yth e existenc e o f particula r facilitie s byconsulting curren t listing s and/o r th e plant s themselves . Th e leve l o f styren e emission s froman ygive n facilit yi s a functio n o f variable s suc ha s capacity , throughput , and contro l measures , and shoul d b e determine d throughdirec t contact s wit hplan t personnel . Thes e operatin g plant s an d location s wer e curren t a s o f Januar y1990 . Source : Referenc e 1



### 2 4P.3 6

1 . 2 . 3 . 4 . 5. LEGEN D O FPLAN TNAME S AN O LOCATION S ARCO , Monaca , PA6 . Dow, Midland , M l Chevron , St . James , L

A7 . Rexen e Products Co. , Odessa , T X Huntsma n Chemical , Bayport , TX8 . Amoco Corporation , Texa s City , TX Cos-Mar , Carville , L

A9 . ARCO , ChanneMew , TX Dow , Freeport , TX10 . Sterlin g Chemicals , Texa s City , TX Figure 2 . Location s ofPlants Manufacturin g Styren e 2 5P.3 7

Styren e manufactur e b yethylbenzen e dehydrogenatio n i s show nb y th e reaction : 

# +

Ethylbenzen e Styren e Hydroge n Figur e 3 illustrate s th e proces s o f ethylbenzen e dehydrogenation . Purifie d ethylbenzen e i s preheate d i n a hea t exchange r (Step 1) , and th e resultan t vapo r i s mixe d continuousl y wit hsteama t 710° C i nth e dehydrogenatio nreacto r (Step 2 ) tha t contain s on e o f severa l catalyst s suc ha s zinc , aluminum , chromium , iron , o r magnesiumoxide . Th e reactio nproduc t exit s throughth e hea t exchange r and i s furthe r coole d i n a condense r wher e wate r an

d crud e styren e vapor s ar e condense d (Step 3) . Th e hydrogen-ric hproces s ga s i s recovere d an d use d a s a fue l (Step 4 ) and th e proces s wate r i s purifie d i n a strippe r (Step 5 ) and recycle d t o th e boiler . Th e remainin g crud e liqui d styren e goe s t o a storag e tank (Step 6) . Th e liqui d consist s o f styren e (37%) , ethylbenzen e (61%) , toluen e (1%) , benzen e (0.7% ) an d tar s (0.3%) . Benzen e and toluen e ar e remove d from th e crud e styren e i n th e benzene/toluen e column(Step 7) . The yar e the n typicall y separate d b

ydistillation . Th e toluen e i s sol d and th e benzen e i s returne d t o th e ethylbenzen e productio n sectio n o r sold . Next , th e ethylbenzen e column remove s ethylbenzen e tha t i s directl yrecycle d (Step 8) . Tar s ar e remove d and th e styren e produc t emerge s fromth e styren e finishing colum n (Step 9) . I n som e facilities , a n ethylbenzene/benzene/toluen e streami s separate d fromth e crud e styren e initiall yand processe d separately . Ethylbenzen e Hydroperoxidatio n Styren e i s currentl ymanufacture d b yethylbenzen e hydroperoxidatio n a t onl yon e facilit yi nth e Unite d States . 

### 2 6Ethylbenzen e Productio n

Benzen e Recycl e Colum n Toluen e

Storag e

Stea m t o

- J Stea m Superheate r

Denote s potentia l locatio n o femissio n source Dehydrogenatio n

Reactio n Sectio n Hydroge n Separatio n Sectio n Styr a ficatlo r rert e .Purificatio n Sectio n Fugitive s fro m overal l proces s Secondarysource s Storag e an d loadin g losses 

### Figur e 3 . Process Flo

wDiagra m fo rStyren e Productio n b yEthylbenzen e Dehydrogenatio nP.3 9

Thi s process , shown i n Figur e 4 , i s describe d below . Styren e manufactur e b

yethylbenzen e hydroperoxidatio n i s show n b yth e reaction :

Qqrga n Propytan a Odd * Wate r Ethylbenzen e i s oxidize d wit hai r t o produc e ethylen e hydroperoxid e and smal l amount s o f methylbenzylalcoho l and acetophenon e (Ste p 1) . Th e exi t ga s (principally-nitrogen ) i s coole d and scrubbe d t o recove r aromatic s befor e venting . Unreacte d ethylbenzen e and low-boilin g contaminant s ar e remove d i n a n evaporato r (Step 2) . Ethylbenzen e i s the nsen t t o th e recoverysectio n t o b e treate d befor e reus e (Step 3) . Th e mixe d streamo f methylbenzylalcoho l and acetophenon e i s the n dehydrate d ove r a soli d catalys t t o produc e styren e (Step 4) . Residua l catalys t solid s and high-boilin g impuritie s ar e separate d and collecte d fo r disposal . Th e crud e styren e goe s t o a serie s o f distillatio ncolumn s wher e th e pur e styren e monome r produc t i s recovere d (Step 5) . Th e residua l organi c streamcontain s crud e acetophenone , catalys t residue , and variou s impurities . Thi s mixtur e i s treate d unde r pressur e wit hhydroge n t o conver t th e acetophenon e t o methylbenzylalcoho l (Step 6) . Catalys t wast e i s separat e fromth e methylbenzylalcoho l whic hi s returne d t o th e recoverysectio nfo r processing and reuse . Hydroge n and organi c vapor s ar e recovere d fo r us e a s fuel . Ethylbenzen e hydroperoxid e i s combine d wit hpropylen e ove r a catalys t mixtur e unde r highpressur e t o produc e propylen e oxid e and acetophenon e (Step 7) . Pressur e i s the n reduce d an d residua l propylen e and othe r low-boiling compound s ar e separate d b y distillatio n (Ste p 8) . Th e ven t streamcontaining propan e and some propylen e ca n b e use d a s a fuel . Propylen e i s recycle d t o th e epoxidatio n reactor . Th e crud e epoxidat e i s treate d t o 2 8Ai r Hydroperoxidatio n Reacto r Evaporatio n E B AC P MBA 

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E B Hydroperoxid e

E B

V O Propylene Epoxidatlo n

Reacto r 

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EB MB A ACP S M LEGEN D Ethylbenzen e Methylbenzylalcoho l Acetophenon e Styren e Monome r Dehydratio n Crud e S M 

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EB.MB A Recover y Sectio n

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Propa m ^ 

# s Recycl e Propylen e

len e Distillatio n 

# © Causti c an d Wate rWas h 

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Oxid e Distillatio n Recycled Was h Wate r 

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Styren e Storag e CatalystWast e

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Loadin g 

## ( Fugitives fro m overal l proces s 

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y sources 

## ( Storag e an d InnHIn n lass a loadin g losses

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### Figur e 4 . Process Flo

wDiagra m fo rStyren e Productio n b yEthylbenzen e Hydroperoxidatio n 4P.4 1

remov e acidi c impuritie s an d residua l catalys t materia l (Step 9 ) and th e resultan t epoxidat e streami s distille d (Step 10 ) t o separat e th e propylen e oxid e produc t fo r 'storage . Residua l wate r and propylen e ar e recycle d t o th e proces s trai n and liqui d distillat e i s recovere d a s a fuel . Th e organi c laye r i s route d t o th e ethylbenzen e and methylbenzylalcoho l recover ysection . Isotherma l Processing An isotherma l proces s fo r producin g styren e from ethylbenzen e wa s patente d i n th e Unite d state s i n 1981. 9 Thi s proces s i s no t currentl yuse d i n th e Unite d States , bu t i t i s use d i n severa l Europea n countries . - ~ A s shown i n Figur e 5 , liqui d ethylbenzen e i s vaporize d by condensin g steami n a hea t exchange r (Step 1) . Proces s steami s the n introduce d int o th e ethylbenzen e stream and th e fee d mixtur e i s superheate d befor e i t enter s th e molten-sal t reacto r (Step 2) . I n th e reactor , th e ethylbenzene/steammixtur e passe s throug htube s wher e i t come s int o contac t wit hth e catalys t and i s dehydrogenated . Hea t fo r th e dehydrogenatio nreactio n i s supplie d b

ymolte n sal t (preferabl ya mixtur e o f sodiu m carbonate , lithiu

mcarbonate , and potassiu m carbonate ) surroundin g th e tubes . Th e reacto r i s maintaine d a t a uniform wal l temperatur e b ycirculatin g th e molten-sal t mixtur e throug h th e hea t exchange r o f a fire d heater . Th e reactio n product s ar e coole d an d condense d i na separato r (Step 3) . Th e liqui d phas e i s a mixtur e o f organi c products : styrene , unreacte d ethylbenzene , and smal l quantitie s o f benzene , toluene , an d high-boilin g compounds . Styren e i s separate d fromth e othe r liqui d constituents , whic har e the n recovere d an

d recycled .



### 3 0u

> Ai rPreheate r

Stea m Generato r Coole r

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Compresso r

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Styren e Storag e Fugitives fro m

overal l proces s Secondary source s Storag e an d loadin g losses 

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# i \Z^ Loadin g

Denote s potentia l locatio n o femissio n source Figure 5 . Proces s FlowDiagra m fo rStyren e Productio n byIsotherma l Processin gP.4 3

Th e ga s phas e fromth e condensatio nste p i n th e separato r consist s mainl yo f hydrogen , wit hsmal l quantitie s o f carbo n dioxide , carbo n monoxide , and methane . Afte r thes e gase s ar e compressed , the yar e cooled . Condensabl e product s fromthi s fina l cooling stag e ar e the n recovere d an d recycle d t o th e separator . Whe n hydrogen-rich ' offga s i s use d a s fue l fo r th e heate r o f th e molten-sal t reactor , th e fue l requiremen t fo r thi s stag e o f th e proces s i s zero . EMISSION S Mos t ai r emission s associate d wit hstyren e productio n aris e fromloading operations , styren e monome r storage , and equipmen t leaks . Proces s vent s ma yals o contribut e t o ai r emission s i n additio n t o secondarysource s (suc ha s wast e treatmen t and disposa l facilities) . Proces s Emission s Figur e 3 show s tha t durin g styren e productio n by ethylbenzen e dehydrogenation , proces s ven t discharge s (A ) o f styren e occu r primaril yfromth e vacuum colum n vents . Th e hydroge n separatio nven t i s onl yuse d durin g startup , shutdown , and durin g recoverysectio noutages. * Th e vacuum colum nvent s remov e ai r tha t leak s int o th e column , a s wel l a s ligh t hydrocarbon s and hydroge ntha t formdurin g dehydrogenation , noncombustible s dissolve d i n th e colum nfeed , and an

yentraine d aromatics . Th e majorit yo f styren e emission s occu r a t th e firs t column , th e benzene-toluen e column , i n th e distillatio ntrain . Althoug hn o specifi c informatio no ncontrol s wa s available , proces s vent s tha t hav e th e potentia l t o emi t benzen e ma yb e controlle d t o preven t occupationa l exposure . Othe r source s o f proces s emission s fromethylbenzen e dehydrogenatio n ar e les s likel ybecaus e o f th e nee d t o operat e mos t processe s unde r a vacuu mand becaus e o f th e heatin g valu e o f th e gases . N o emissio n estimate s fo r styren e productio n 3 2P.4 4

processe s wer e locate d i n th e literature . Also , littl e informatio n wa s found o n emissio ncontrols . On e typ e o f contro l optio n i s incineration , whic hca n reduc e styren e emission s bya s muc ha s 9 8 percent. *

N o informatio n wa s locate d i n th e literatur e tha t discusse d proces s emissio n source s fromstyren e productio n byethylbenzen e hydroperoxidatio n o r th e isotherma l productio nprocess . Styren e emission s mayoccu r durin g th e styren e refining proces s fo r eac h o f thes e productio n processes . Storag e Emission s Othe r possibl e source s o f styren e emission s ar e storag e tank losse s (B ) and handlin g losse s (C ) tha t occu r durin g produc t loadin g int o drums , tan k trucks , tan k cars , barges , o r ships . Styren e productio n plant s typicall yhav e from2 t o 1 2 small , i fixed-roo f monome r storag e tanks . Storag e tank losse s ar e eithe r workin g losse s tha t occu r whil e fillin g th e tank , o r breathin g losse s du e t o expansio n from temperatur e changes . Bot hca nb e estimate d usin g equation s fo r storag e tank emission s give n i n th e U . S . Environmenta l Protectio n Agency' s "Estimating Ai r Toxi c Emission s from

Organi c Liqui d Storag e Tanks " report. 6 i n th e absenc e o f specifi c dat a o nth e storag e tank , tw o emissio n factor s wer e identifie d i nth e literature. 7 Showni n Tabl e 5 , bot har e fo r uncontrolle d emissions . N o facilitie s ar e knownt o currentl ycontro l emission s wit hfloatin g roo f tank s o r incineration , althoughsevera l us e condensin g unit s t o recove r styrene. 2 Eguipmen t Lea k Emission s Emission s occu r fromproces s equipmen t component s wheneve r th e liqui d o r ga s stream s leak fro m th e equipment . Equipmen t leak s ca n occu r fromth e followin g components : pum p seals ,



### 3 3P.4 5

TABL E -5 . STYRENE STORAGE AN DSECONDAR

YEMISSIO

N FACTOR S EmissionSourc e Storage BreathingLoss ' WorkingLoss * EstimatedEmissio nFactor

0.1 8 g/ L (1. 5 lbs/1 0 lbs ) storag e capacit y

3 0.0 2 g/ L (0.1 7 lbs/1 0 lbs ) gallon s throughpu t Secondar

y Wastewate r Treatment* 1 0.5 0 g/ g(0.5 0 lb/lb ) styrene i n

"Source : Referenc e 7 . Source : Referenc e 8 . wastewate r

3 4P.4 6

proces s valves , compresso r safet yrelie f valves , flanges , open ende d lines , and sampling connections . Fugitiv e emission s wil l b e primaril ylimite d t o th e stream s containin g n o benzen e becaus e o f th e Nationa l Emissio n Standar d fo r Hazardou s Ai r Pollutant s (NESHAP ) tha t applie s t o equipmen t i nbenzen e service . Thi s NESHA P addresse s al l equipmen t component s handling proces s stream s containin g 1 0 percen t byweigh t o r greate r benzene . Emissio n estimate s ca n b e calculate d i n th e fiv e way s describe d i n th e EP Apublicatio n "Protocol s fo r Generatin g Unit-Specifi c Emissio n Estimates." 9 Th e method s diffe r i n complexity ; however , th e mor e complex , th e bette r th e emissio nestimate . Th e simples t metho d require s tha t th e numbe r o f eac h componen t typ e b e known . Furthermore , fo r everycomponen t th e styren e conten t o f th e streamand th e tim e th e componen t i s i n servic e i s needed . Thi s informatio n i s the nmultiplie d b yth e EPA' s averag e emissio n factor s fo r th e Syntheti c Organi c Chemica l Manufacturin g Industrie s (SOCMI ) shown i nTabl e 6 . Thi s metho d shoul d onl yb e use d i f n o othe r dat a ar e available , a s i t probabl yresult s i n a n overestimatio n o f actua l equipmen t lea k emissions . Fo r eac hcomponent , estimate d emission s are :

No . o f equipmen t components . Weigh t %

styren e i n th e strea m Component-specifi c

emissio nfacto r No . hrs/y r i n styren e servic e

T o obtai n bette r equipmen t lea k emissio nestimate ? th e mor e comple xestimatio nmethods , shoul d * ~ fou r method s requir e tha t som e leve l o f em i th e facility' s equipmen t component s b e col l describe d briefly , and th e reade r i s referr e documen t fo r th e calculatio n details . / 

# A Ater may 3 5P.4 7

TABL E 6 . AVERAG E EMISSIONFACTOR S FORFUGITIVE EMISSION S

Equipmen t Servic e Emissio nFacto r (Kg/hr / Source ) (Lb/hr /

Source ) Valve s Pum p Seal s Compresso r Seal s Pressur e Relie f Seal s Flange s Open-Ende d Line s Samplin g Connection s Ga s Ligh t Liqui d Heav yLiqui d Ligh t Liqui d Heav yLiqui d Gas/Vapo r Gas/Vapo r Al l Al l Al l 0.005 6

0.007 1 0.0002 3 0.049 4 0.021 4 0.22 8 0.10 4 0.0008 3 0.001 7 0.015 0 0.01 2

0.01 6 0.0005 1 0.10 9 0.47 2 0.50 3 0.22 9 0.001 8 0.003 7 0.03 3 Source : Referenc e 9 .



### 3 6P.4 8

Th e leak/n o leak approac hi s base d o n a determinatio no f th e numbe r o f leakin g an d non-leakin g components . Thes e value s ar e the n multiplie d b

ytw o differen t set s o f EPA-derive d emissio n factors . Th e thir d metho d group s screenin g result s int o thre e ranges : 0-1,00 0 ppmv ; 1,001-10,00 0 ppmv ; an d greate r tha n10,00 0 ppmv . Th e numbe r o f eac hcomponen t falling i na particula r rang e i s multiplie d byth e component-specifi c emissio n facto r fo r tha t range . Thes e emissio n factor s hav e als o bee n develope d byEPA . Th e fourt hprocedur e use s screenin g dat a i n correlatio nequation s derive d fromearlie r wor k byEPA . Th e fift hmetho d give s th e facilit yth e optio n t o develo p it s own correlatio n equation s bu t require s mor e rigorou s testing , baggin g and analyzing o f equipmen t leak s t o determin e mas s emissio n rates . Althoug hn o specifi c informatio no n control s use d byth e industrywa s identified , equipmen t component s i n benzen e servic e wil l hav e som e control s i nplace . Generally , contro l o f fugitiv e emission s wil l requir e th e us e o f sealles s o r doubl e mechanica l sea l pumps , a n inspectio n and maintenanc e program , a s wel l a s replacemen t o r leaking valve s and fittings . Typica l control s fo r equipmen t leak s ar e liste d i nTabl e 7 . Additionally , som e leakles s equipmen t i s availabl e suc ha s leakles s valves 1 0 and sealles s pumps. 2 SecondaryEmission s Secondaryemission s occu r a t bot hon-sit e and off-sit e facilitie s tha t trea t and dispos e o f wastewater , liqui d waste , o r soli d waste . Wast e stream s ma yb e generate d fo r anyo f th e operation s shown i n Figure s 3 , 4 , and 5 . Fo r secondaryemission s resultin g fromtreatmen t o f wastewate r containing styrene , on e referenc e estimate d tha t approximatel y5 0 percen t o f th e styren e presen t i nth e wate r may 

### 3 7TABL E 7 . CONTRO L TECHNIQUE S AND EFFICIENCIE S APPLICABL E T O EQUIPMENT LEAK EMISSION S Equipmen t Componen t (Emissio n Source ) Pum p Seal s Packe d and Mechanica l

C J 0 3 Doubl e Mechanical 1 Compressor s Flange s Valve s Ga s Liqui d Contro l Techniqu e Sea l are a enclosur e vente d t o a combustio n devic e Monthl yLDAR b Quarterl yLDA

R Semiannua l LDA

R Annua l LDA

R N/A d Ven t degassin g reservoi r t o combustio n devic e Non e availabl e Monthl yLDAR Quarterl yLDA

R Semiannua l LDAR . Annua l LDAR Monthl yLDA

R Quarterl yLDA

R Semiannua l LDAR Annua l LDAR Percen t Reduction " 10 0 6 1 3 2 0 0 10 0 0 7 3 6 4 5 0 2 4 5 9 4 4 2 2 0TABL E 7 . (Continued )

u > VO Pressur e Relie f Device s

Ga s Monthl yLDA R5 0 Quarterl yLDA

R4 4 Ruptur e Dis k 10 0 Liqui d N/ A Sampl e Connection s Closed-purg e samplin g 10 0 Open-ende d Line s Cap s o n ope n end s 10 0 "I f Referenc e 1 0 indicate d a negativ e reductio nfo r a contro l technique , zer o wa s used . *LDA R= Lea k detectio n and repair . cAssume s th e sea l barrie r flui d i s maintaine d a t a pressur e abov e th e pum p stuffin g bo x pressur e an

d th e syste mi s equippe d wit ha senso r tha t detect s failur e o f th e sea l and/o r barrie r flui d system . d N/ A= No t applicable . Ther e ar e n o VO C emission s fromthi s component . Source : Reference s 2 and 10 .



## YP.5 1

b e release d durin g processing a t a publicl yowne d treatmen t work s (POTW ) facility. 1 1 Thi s emissio nfacto r i s give ni nTabl e 5 . N o informatio n wa s availabl e o n th e styren e conten t i nth e wastewater . Furthermore , handlin g and processing practice s wil l diffe r wit heac hfacility ; therefore , th e emissio n facto r shoul d be.reviewe d a s providing a norder-of-magnitud e estimat e a t best .

y



### 4 0 

# VP.5 2

REFERENCE S FO RSECTION4

1 . SR I International . 199 0 Director yo f Chemica l Producers , Unite d state s o f America . Menl o Park , California . 1990 . 2 . A . T . Kearney . Impac t Analysi s o f th e EP AOffic e o f Drinking Wate r Proposa l t o Regulat e Styrene . Styren e Informatio n Researc hCenter . 1989 . 3 . U . S . Environmenta l Protectio n Agency . Benzen e Emission s - fromth e Ethylbenzene/Styren e Industry- Background Informatio n fo r Propose d Standards . EPA-450/3-70-035a . U . S . Environmenta l Protectio nAgency , Researc hTriangl e Park , Nort hCarolina . 1980 . 4 . Cruse , P . A . Locatin g an d Estimatin g Ai r Emission s from Source s o f Benzene . EPA-450/4-84-007q . U . S . Environmenta l Protectio n Agency , Researc hTriangl e Park , Nort hCarolina . 1988 . 5 . Short , H . C . and L . Bolton . Ne wStyren e Proces s Pare s Productio n Costs . Chemica l Engineering . August : 30-31 . 1985 . 6 . Murphy , P . Estimatin g Ai r Toxic s Emission s From Organi c Liqui d Storag e Tanks . EPA-450/4-88-004 . U . S . Environmenta l Protectio nAgency , Researc hTriangl e Park , Nort hCarolina . 1988 . 7 . Stockton , M . B . an d J . H . E . Stelling . Criteri a Pollutan t Emissio n Factor s fo r th e 198 5 NAPA P Emission s Inventory . EPA-600/7-87-015 . U . S . Environmenta l Protectio nAgency , Washington , D.C . p . 134 . 1987 . 8 . Pope , A . A. , e t ai . Toxi c Ai r Pollutan t Emissio nFactor s - ACompilatio n fo r Selecte d Ai r Toxi c Compound s an d Sources . EPA-450/2-88-006 . U . S . Environmenta l Protectio n Agency , Researc hTriangl e Park , Nort hCarolina . 1988 . 9 . U . S . Environmenta l Protectio nAgency . Protocol s fo r Generating Unit-Specifi c Emissio nEstimate s fo r Equipmen t Leak s o f VO C and VHAP . EPA-450/3-88-010 . U . S . Environmenta l Protectio nAgency , Researc hTriangl e Park , Nort hCarolina . 1988 . 10 . U . S . Environmenta l Protectio nAgency . Fugitiv e Emissio n Source s o f Organi c Compounds—Additiona l Informatio no n Emissions , Emissio n Reductions , and Costs . EPA-450/3-82

- 010 . U . S . Environmenta l Protectio nAgency , Researc h Triangl e Park , Nort hCarolina . Apri l 1982 .



### 4 1P.5 3

11 . White , T . S . Volatil e Organi c Compound Emission s from Hazardou s Wast e Treatmen t Facilitie s a t DownstreamPOTW . Prepare d fo r th e U . S . Environmenta l Protectio nAgency , Researc hTriangl e Park , Nort hCarolina , pp . 5-6 . 1987 .



### 4 2P.5 4

SECTION5 EMISSION S FROMMAJO RUSE S O F STYRENE Thi s sectio n discusse s emission s frommajo r industria l processe s tha t us e styren e a s a feedstock . Th e processe s describe d ar e productio n o f polystyren e (PS ) polymer , styrene butadien e copolymer s (S-B , SBR) , styrene-acrylonitril e copolyme r (SAN) , acrylonitrile-butadiene-styren e copolyme r (ABS) , and unsaturate d polyeste r resin s (UPR) . I n addition , produc t and proces s description s ar e provide d fo r th e miscellaneou s styren e copolymers : styrene-butadiene-vinylpyridin e (SBV ) latex , methy l methacrylate-butadiene-styren e (MBS ) resins , an d methy l methacrylate-acrylonitrile-butadiene-styren e (MABS ) polymer . Proces s flo wdiagram s ar e include d a s appropriate , wit hspecifi c stream s o r vent s i n th e figure s labele d t o correspond wit hth e discussio n i n th e text . Emission s o f styren e ar e expecte d fromal l facilitie s tha t produc e th e abov e liste d resins . However , insufficien t informatio n i s availabl e t o develo p emissio nfactor s fo r fugitive s o r proces s emissio nsources . Availabl e informatio ni s provide d i n eac hsubsection . Th e reade r i s encourage d t o contac t Stat e o r loca l ai r pollutio ncontro l agencies , th e toxi c releas e inventory , and specifi c productio nfacilitie s fo r informatio no n styren e emission s and contro l technologies . POLYSTYRENE PRODUCTION Polystyren e i s produce d b yth e polymerizatio no f styren e monomer . Th e polyme r i s availabl e i n a wid e rang e o f formulation s includin g crystal , hig himpac t an d expandabl e (EPS) . Crysta l P S i s th e genera l purpos e grade. . I t i s a clear , rigi d plasti c wit hexcellen t electrica l and insulatio n propertie s and lo wimpac t resistance. 1 T o increas e th e toughnes s o f th e polystyren e plastic , rubbe r particle s (usuall ypolybutadiene ) may 

### 4 3P.5 5

b e incorporate d int o th e polyme r matrix . Thi s rubber-modifie d formi s known a s hig himpac t PS. 2 Expandabl e polystyren e i s produce d b

yth e additio no f a volatil e blowing agen t t o th e polystyren e whic hcause s th e polyme r t o expand whe n heated . Th e blowin g agen t mayb e adde d durin g th e polymerizatio nproces s o r durin g th e fabricatio n process. 3 Polystyren e i s use d i ninjectio nan d extrusio nprocesse s t o produc e a wid e variet yo f products . Th e majo r en d us e fo r P S i s i n packaging . Th e resi n als o find s application s i n th e building , electronics , furniture , housewares , and recreationa l marketin g areas . Polystyren e i s th e leading resi n use d fo r makin g toys . Injectio n molding i s use d t o mak e product s suc ha s tumblers , toot hbrus hhandles , compute r dis k reels , pil l bottles , and toys . Extrusio n i s use d t o mak e eg g cartons , meat/poultrytrays , and fast-foo d packages . Crysta l P S i s use d t o mak e fast-foo d package s an

d eg g cartons . Hig himpac t P S i s use d t o produc e fast-foo d cups , lids , and containers , toys , container s fo r food , frui t juices , an

d dairyproducts , kitche nhousewares , and smal l appliances . Expandabl e PS , whic hi s eas yt o process , i s use d t o mak e disposabl e drinkin g cups , loos e fil l packaging , insulation , and packaging shapes . Polystyren e i s commonl ymarkete d i nbea d o r pelle t form ; however , som e i s captivel yconverte d t o film , sheet , o r foam. * Polystyren e i s currentl yproduce d b y1 7 companie s a t 3 4 facilitie s i n 1 6 States . Thes e facilitie s an d thei r 199 0 productio n capacitie s ar e liste d i n Tabl e 8. s Manufactur e o f polystyren e i s th e majo r end us e o f styren e monomer , consumin g approximatel y6 8 percen t o f th e styren e produce d i nth e Unite d States. 6

Proces s Descriptio n Polystyren e mayb e produce d b yth e suspension , mas s (bulk) , solution , an

d emulsio n processes . Th e suspensio nproces s i s

4 4P.5 6

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4 5TABL E 8 . (Continued ) Akron , O H Decatur , AL Leominster , MA Springfield , MA For t Worth , TX Cit yo f Industry , C A TOTAL 54,43 1 63,50 3 72,57 5 71,64 7 34,92 7 29,94 8 3,045,419 * - 12 0 14 0 16 0 18 0 7 7 5 5 6,71 4

c n Polysa r

Scot t Polymer s Tennec o 'Number s d o no t tota l du e t o rounding . NOTE : Th e listing o n Tabl e 8 i s subjec t t o chang e a s marke t condition s change , facilit y ownershi p changes , plant s ar e close d down , etc . Th e reade r shoul d verif yth e existenc e o f particula r facilitie s b yconsulting curren t listing s and/o r th e plant s themselves . Th e leve l o f styren e emission s fromanygive nfacilit yi s a functio no f variable s suc ha s capacity , throughput , an d contro l measures , and shoul d b e determine d throug hdirec t contac t wit hplan t personnel . Thes e operatin g plant s and location s wer e curren t a s o f January1990 . Source : Referenc e 5 .P.5 8

operate d i n a batc hmode , wherea s th e mas s and solutio n processe s ar e operate d i n th e continuou s mode. 7 Th e mas s and suspensio n method s ar e commerciall ysignificant. 7 Us e o f th e emulsio n proces s fo r P S productio n ha s decrease d significantl ysinc e th e mid-1940's. * I t i s no t use d fo r th e productio no f crysta l P S becaus e th e soap solutio n (emulsifier ) adversel yaffect s th e clarit yan

d electrical-insulatio ncharacteristic s o f th e product. 3 Therefore , th e emulsio n proces s wil l no t b e discusse d here . T o produc e impac t grad e polystyrene , th e rubbe r componen t ma yb e incorporate d b ymechanica l mean s afte r styren e polymerizatio n o r i t ma yb e adde d t o th e polymerizatio n reacto r alon g wit hth e styren e monomer . I f mechanica l mean s ar e used , rubbe r late xma yb e adde d t o polystyren e late xfollowe d by coagulatio n an

d drying , o r dryrubbe r ca nb e mille d wit hdry polystyrene . Alternatively , choppe d preforme d unsaturate d rubbe r ca n b e dissolve d int o styren e monome r an d the nth e mixtur e ca n underg o polymerizatio n byan yo f th e thre e processe s describe d below. 3 Mos t impac t P S i s produce d b ysuspensio n polymerization. 3 Expandabl e polystyren e i s produce d b ymodifyin g th e batc h suspensio n process . Ablowin g agent , suc ha s n-pentane , mayb e adde d t o th e reacto r befor e o r afte r polymerizatio n and i s absorbe d b

yth e polystyrene . Th e post-impregnatio nproces s i s mor e commonl yused. 8 I n thi s metho d th e finishe d polystyren e produc t bea d fromth e suspensio n proces s i s fe d throug ha second suspensio n proces s trai n wher e th e blowing agen t i s impregnate d int o th e produc t bead s throug hth e us e o f temperatur e and applie d pressure .



### 4 7Suspensio n Process — Th e suspensio n proces s (Figur e 6 ) i s a batc hpolymerizatio n proces s tha t mayb e use d t o produc e crystal , impac t o r expandabl e polystyren e beads . I nthi s process , polymerizatio n i s carrie d ou t i n a n aqueou s mediumt o permi t remova l o f th e hea t o f ther e action. 1 Th e polystyren e polyme r i s forme d i n smal l bead s whic h ar e easil yseparate d fromth e aqueou s phase . Styren e monome r fromstorag e i s firs t washe d t o remov e an y inhibitor s o f th e polymerizatio n reactio n(Step l) . Th e washe d styren e i s transferre d t o a mixin g tank wher e i t i s combine d wit h a fre e radica l initiato r (Step 2) . Th e styren e i s the nfe d int o a n agitate d reacto r alon g wit hwater , initiator , a monome r solubl e suspending agen t and suspensio n stabilize r (Step 3) . A blowin g agen t o r rubbe r ma yb e adde d a t thi s tim e fo r th e productio n o f expandabl e P S o r highimpac t P S respectively . Bot h th e blowing agen t and th e rubbe r mayals o b e adde d late r a s par t o f a pos t polymerizatio n process . Following polymerization , th e polyme r bead s ar e transferre d t o a was htank wher e the yar e washe d wit haci d t o remov e initiator s and suspensio nstabilizer s (Step 4) . Th e we t bead s ar e sen t t o a centrifug e (Step 5 ) and the n a drye r (Step 6 ) fo r dewatering and drying . Th e bead s ar e passe d t o a devolatilizatio n extrude r fo r recover yo f unreacte d styren e monome r (Step 7) . Recovere d monome r i s recycle d int o th e polymerizatio n reactor . Th e purifie d polyme r bead s ar e drie d and sen t t o produc t storage. 3

Mas s Process — Th e mas s proces s use s n o wate r o r organi c solvent s an d i s th e simples t proces s fo r producing polystyrene . A s show ni n Figur e 7 , ther e ar e fou r majo r stage s i nth e mas s process : prepolymerization , polymerization , devolatilization , an d extrusion . Styren e monome r i s strippe d o f inhibitor s i na steam strippe r (Ste

p 1 ) the n pumpe d int o a stirre d prepolymerizatio n



### 4 8 

# Iv

o Styren e - Steam 

# X

Monome r Was h 

### < £ T o Wastewate r

Treatmen t 

# A

Radica l Initiato r- Mixing Tan k

### <S >

Wate r Dispersin g Agen t Suspensio n Stabilize r

(Rubber ) (Blowin g Agent)

Denotes potentia l locatio n o femissio n source 4

,

• Fugitives fro m overal l proces s Secondarysource s Storag e an d loadin g losses

Reacto r 

## © Aci d Wate r 

# L-C- ® © ®

Devolatilizatio n Extruder ^

T o Wastewate r Treatmen t T o Wastewate r

Treatmen t Polystyren e

Bead s Polystyren e

Pellets Figure 6 . Polystyren e Productio n bySuspensio n Polymerization 1o Styren e -

Stea m 

# X

Monome r Was h 

# ©

InitiatorFugitives fro m overal l proces s .T o Wastewate r Treatmen t 

# © Prepolymerizatio n

Reacto r Lo wMolecula r -* - Weigh tPolyme r t o Landfil l 

# i

Extruder . Polystyren e Pellet s Secondar

ysource s Storag e an d loadin g losses Denote s potentia l locatio n ofemissio n source 

### Figur e 7 . Polystyren e Productio n b yMass Polymerization 'P.6 2

reacto r equippe d wit ha refluxcondense r operatin g unde r reduce d pressur e (Step 2) . Reactio n temperatur e i s controlle d by removing som e o f th e monome r vapor , condensin g it , and the n returnin g th e liqui d monome r t o th e reactor . Polymerizatio nmay b e initiate d eithe r thermall yo r throug hth e us e o f chemica l initiators . I n thi s reacto r monome r conversio nproceed s t o 2 5 t o 3 5 percent . Th e polyme r mel t i s the nfe d throug ha serie s o f stirre d refluxreactor s (Step 3) . Th e reactio ntemperatur e i s continuall yraise d t o promot e polymerizatio nand reduc e th e viscosit yo f th e polyme r mass . Fina l temperature s typicall y rang e from15 0 t o 200"C . Th e polyme r mel t i s transferre d t o a stati c devolatilize r (Step 4 ) wher e unreacte d monome r and lo w molecula r weigh t polymer s ar e flashe d of f distille d and recycle d (Step 5) . Th e strippe d polyme r i s fe d througha ven t extrude r and pelletize d (Step 6). 3 Solutio n Process- — Abloc k diagramo f th e polystyren e solutio nproces s i s presente d i n Figur e 8 . I n thi s process , polymerizatio n proceed s i n a solven t medium . I n Ste p l , styren e monome r i s steam strippe d t o remov e an yinhibitor s o f th e polymerizatio n reaction . Th e washe d styren e monome r i s mixe d wit ha solven t (suc ha s ethylbenzene ) and a n initiator , the nfe d througha serie s o f agitate d reactor s (Step 2) . Th e initia l ethylbenzen e concentratio n ma yrang e from 5 t o 2 5 percent . Followin g polymerizatio n th e polyme r mi xi s sen t t o a flas htan k fo r th e remova l o f unreacte d styren e an d solven t (Step 3) . Recovere d styren e and solven t ar e recycle d wit hth e reacto r feed . Th e purifie d polyme r i s fe d througha nextrude r and choppe d int o pellet s (Step 4). 3 Emission s Typica l emissio n source s a t a polystyren e plan t includ e proces s vents , storag e tanks , equipmen t leaks , secondar ysources , 

### 5 1O l

M Styrene Stea m Monome r

Was h 

## © _^

. T o Wastewate r

Treatmen t

Ethylbenzen e Initiato r Ras h Tan k 

## ®, 

# A 

# 1

Extruder 

## ®

Denotes potentia l locatio n o femissio n source Polystyren e Pellets Fugitive s fro m

overal l proces s Secondar ysource s c

5 Storag e an d loadin g losse s 

### Figur e 8 . Polystyren e Productio n b vSolutio n Polvmrwatinn "P.6 4

and transfe r an

d handlin g operations . Styren e mayals o b e emitte d durin g accidenta l o r emergenc yreleases. 3 Styren e mayb e emitte d fromreacto r vents , mixin g tanks , was htanks , devolatilize r condense r vents , styren e recover yuni t condense r vents , and durin g polyme r dryin g and finishin g stages. 3 Th e monome r storag e tank , th e mixing/dissolvin g tanks , an d th e reacto r fee d tank typicall yhav e fixe d roofs. 4 Emission s from thes e source s ar e relativel ysmal l an d ar e du e t o norma l breathin g and fillin g o f th e tanks. 4 Vapo r balanc e us e o n workin g condenso r i s th e larges t styren e emissio nsourc e i na polystyren e plant ; however , th e quantit yo f emission s i s no t particularl ylarge. 4 ' * Followin g th e devolatilizatio nstep , residua l styren e monome r i n th e polyme r i s typicall yles s tha n on e percent. 3 Th e extrude r pelletize r ven t i s potentiall yth e second larges t styren e emissio n source. 4

Ven t emission s ma yb e controlle d b yroutin g th e proces s stream s t o a flar e o r a blowdown tank. 6 Conservatio nvalve s ca n b e installe d o n holdin g and mixin g tanks. 4 Vapo r retur n line s t o tank car s o r truck s ca n b e installe d t o reduc e styren e losse s durin g storag e tan k filling. 4 Fugitiv e emission s resul t fromleak s i nflanges , valves , pumps , ope n drains , an d othe r equipmen t components . Contro l o f thes e emission s ma yb e accomplishe d throug ha regula r inspectio n and maintenanc e program a s wel l a s b

yequipmen t modification . Th e mod e o f operatio n als o influence s emissions . Batc h processe s generall yhav e hig hconversio n efficiencies , leaving onl ysmal l amount s o f unreacte d styren e t o b e emitte d i f th e reacto r i s purge d o r opene d betwee nbatches. " I n continuou s processe s a lowe r percentag e o f styren e i s converte d t o polystyrene , and thu s large r amount s o f unreacte d styren e mayb e emitted. '



### 5 3P.6 5

Facilitie s usin g batc hprocesse s ma ymanufactur e a wid e variet yo f polystyren e products . Styren e emission s var ywit hth e produc t grad e wit hhighe r emission s expecte d durin g th e manufactur e o f lowe r molecula r weigh t products. 1 0 Typica l emissio n facto r range s suggeste d b yth e Chemica l Manufacturer s Associatio n (CMA ) fo r thre e batc hproces s vent s ar e presente d i n Tabl e 9 . Fo r plant s usin g th e continuou s process , a wid e rang e o f emissio n rate s hav e bee n found , dependin g i npar t o n th e typ e o f vacuumsystem

used. * Th e shif t from th e us e o f steameductor s t o vacuumpump s result s i n lowe r emissio n factors. 1 0 Tabl e 9 present s VO C emissio nfactor s give n b yCMAfo r th e continuou s polystyren e plants . Emissio n factor s fo r th e sam e vent s base d o n informatio n from

othe r industrysource s ar e als o presente d i n Tabl e 9. 9 STYRENE-BUTADIENE COPOLYME RPRODUCTION Styrene-butadien e copolymer s ar e compose d o f monome r unit s o f styren e an

d butadiene . Th e copolymer s ma yb e categorize d int o tw o genera l types : styrene-butadien e rubbe r (SBR ) and styrene-butadien e late x(S- B latex) , base d o npercen t styren e composition . However , th e exac t nomenclatur e fo r th e differen t type s o f styrene-butadien e copolymer s i s ofte nuse d differentl y betwee n th e plastic s an d rubbe r industry . SB Rcopolymer s contai nles s tha n 4 5 percen t styren e and hav e rubber-lik e qualities . The yar e characterize d byprocessability , hea t aging , an

d abrasio nresistance . SB Rca n b e i na soli d (elastomer ) o r late x(elastome r emulsion ) form . Th e soli d for m o f th e copolyme r i s als o knowna s crumb . A s th e styren e conten t i s increase d abov e 4 5 percent , copolymer s become mor e plastic-lik e an d ar e i nlate xform . The y ma yb e referre d t o a s S- B latex . S- B late xi s characterize d b y



### 5 4TABL E 9 . EMISSIONFACTOR S FOR POLYSTYREN E PRODUCTIO N Uncontrolle d Emissio n Rat e Emissio n Sourc e Fee d dissolve r (mixing tank ) Proces s (K g Styrene / (L

bStyrene / Typ e Mg Resin ) To n Resin ) Continuou s 0.00 9 0.01 8 Stream Compositio n 92 % styrene * 7.5 % polybutadien e 1.5 % othe r Ref ,

O l O l Reacto r headin g ven t Devolatilize r condense r ven t

Styren e recover y uni t condense r ven t Extrude r quenc h ven t Batc h

Batc h Continuou s Continuou s Continuou s Continuou s Batc h Continuou s Continuou s 0.15-1.3 5

0.25-0.7 5 0.05-0.0 6 0.05-2.9 6 0.05-0.0 6 0.05-0.1 3 0.15-0.3 0 0.009-0.0 1 0.1 5 0.3-2. 7

0.5-1. 5 0.10-0.1 2 0.10-5.9 2 0.10-0.1 2 0.10-0.2 6 0.30-0.6 0 0.018-0.0 2 0.3 0 N/A b

N/ A N/ A 21.8 % styren e 78.2 % stea m N/ A. 2.1 % styren e 97.9 % stea m N/ A N/ A trac e styren e 99.99 % stea m 1 0 1 0 1 0 9 1 0 9 1 0 1 0 9 "I t i s assume d tha t number s d o no t tota l du e t o rounding . "No t available .P.6 7

excellen t resistanc e t o wate r and ver ygoo d electrica l insulatio n qualities . Styrene-butadien e copolymer s accoun t fo r 1 3 percen t o f nationa l styren e consumption. 6 S B copolymer s ar e produce d b y1 3 companie s a t 2 3 facilitie s i n1 2 states . Elastome r and late x productio n facilitie s ar e liste d i n Table s 1 0 and 11 , respectively . Th e U . S . annua l productio ncapacit yo f S B copolymer s fo r 199 0 i s estimate d t o b e 1,575,69 1 M g (347 4 M Mlbs) , 6 1 percen t elastome r an d 3 9 percen t latex. 8 Mos t SB Relastome r i s use d t o manufactur e automobil e tire s and relate d automotiv e products . I nth e Unite d States , SB Rha s th e highes t productio n rat e o f al l syntheti c rubbers . However , due " t o th e longe r lif e o f tire s and th e us e o f smalle r tires , U . S . demand fo r SB Ri s declining . Othe r automotiv e use s o f SB Rinclud e belts , hoses , gaskets , and seals . Non-automotiv e use s o f SBR includ e cabl e insulation , hoses , tubes , conveyo r belts , floo r tiles , sho e soles , adhesives , and sportin g goods . Ove r 8 0 percen t o f styrene-butadien e latexe s ar e use d i n th e carpet/upholsterybacking and pape r coatin g industries. 3

Proces s Descriptio n Styrene-butadien e elastome r i s manufacture d b ytw o type s o f polymerizatio n processes : (1 ) th e emulsio nprocess , i n whic hth e monomer s ar e disperse d i n water , and (2 ) th e solutio nprocess , i n whic hth e monomer s ar e dissolve d i na solvent . Th e emulsio n proces s i s mor e commonl yused . Styrene-butadien e late xi s produce d b

yth e emulsio nproces s i na simila r manne r t o SBR , excep t tha t th e emulsio n breakin g (coagulation ) and dryin g step s ar e omitted . Emulsio n Process — Aflowdiagram

o f th e emulsio nproces s fo r SB Relastome r productio n i s shown i n Figur e 9 . I nSte p l , fres hstyren e an d 

### 5 6P.6 8

TABL E 10 . SB RELASTOME RPRODUCTIO

NFACILITIE S

Compan y Ameripo l Copolyme r Fireston e Genera l Tir e Goodyea r Locatio n Por t Neches , T X Bato n Rouge , L A Lak e Charles , LA Odessa , T X Beaumont , T X Houston , T X TOTA L Annua l (Mg/yr ) 336,00 0 125,00 0 120,00 0 90,00 0 20,000 * 305.00 0 996,00 0 Capacit y

(M MIb/yr ) 74 1 27 6 26 5 19 8 4 4 67 2 2,19 6 "Fo r captiv e use . NOTE : Thi s listing i s subjec t t o chang e a s marke t condition s change , facilit yownershi p changes , plant s ar e close d down . etc . Th e reade r shoul d verif yth e existenc e o f particula r facilitie s b yconsultin g curren t listing s and/o r th e plant s themselves . The , leve l o f styren e emission s froman ygive n facilit yi s a functio n o f variable s suc ha s Capacity , throughput , and contro l measures , and shoul d b e determine d throughdirec t contac t wit hplan t personnel . Thes e operatin g plant s and location s wer e curren t a s o f January1990 . Source : Referenc e 5 .



### 5 7P.6 9

TABL E 11 . STYRENE-BUTADIENE LATE XPRODUCTIONFACILITIE S

Compan y SB RLATEX * BAS F B.F . Goodric h GenCorp Goodyea r

S- B LATEX * BAS F B.F . Goodric h Colloid s Do wChemica l Locatio n

Chattanooga , TN Akron , O H Mogadore , O H Akron , O H Calhoun , G

A Houston , TX

TOTAL Chattanooga , T N Monaca , PA Akron , OH Gastonia , G

A Dalton , G

A Annua l Capacit y

(Mg/yr ) (M

M 9,03 0 907 " 6,804 b 3,175 ° 5,443 b 22.68 0 68,03 9 49,89 5 24,94 8 90 7 15,87 6 181,43 7 lb/yr ) 6 4 2 1 5 7 1 2 5 0 15 0 11 0 5 5 2 3 5 40 0

GenCorp Goodyea r Reichhol d W.R . Grac e Unoca l Freeport , TX

Gale s Ferry , C T Midland , M I Pittsburg , C

A Mogadore , OH Calhoun , G

A Cheswold , DE Kensington , G

A Owensburg , K

Y Charlotte , NC L a Mirada , C

A TOTAL 84 ,

39 , 69 , 4 , 27 , 12 , 511 , ,82 2

r 91 6

r 85 3 ,53 6 ,21 6 ,24 7 ,652 * 18 7

8 8 15 4 1 0 6 0 2 7 1,12 8 *<45 % styren e .. . , . "Capacityinclude s s-b-vinylpryidin e latex . Capacit yi s al l s -b-vinylpyridin e latex . d >45 % styren e ^ . . •Number s d o no t tota l due t o rounding . NOTE * Thi s listing i s subjec t t o chang e a s marke t condition s chana e facilit vownershi p changes , plant s ar e close d down , etc . T I S reade r snoH d verif ythe existenc e o f particula r facilitie s b vconsulting curren t listing s and/o r th e plant s themselves . Th e leve l o f styren e emissionfro man ygive n facilit yi s a functio n o f variable s suc ha s capacity , throughpu t an d contro l measures , an d shoul d b e determine d throug hth e direc t contac t wit hplan t personnel . Thes e operatin g plant s and location s wer e curren t a s o f January1990 . Source : Referenc e 5 .

5 8Styrene ,

Butadien e Recycle d Monomers

O l v o 

# ©

Monome r Was h 

## © 

# ©

Reactors

Activator , Modifiers , Soa p Solution , Catalyst , Wate r

Denotes potentia l locatio n o femissio n source 

## © 

# ©

Monome r Recover y 

## ®

Shortsto p Antioxidan t 

# © Acid-brin e

Blendin g 

# ®

Coagulatio n Washin g an d Dryin g

S-B/SB R • » Latex SB R Elastome r

Fugitives fro m overal l proces s Secondarysource s Storag e an d loadin g losses 

### Figur e 9 . S-B/SB R Productio n b yEmulsio n Polymerization 1 1P.7 1



### butadien e monomer s ar e washe dt o remov e inhibitor s whic hma yhav e bee nadde dt o preven t prematur e polymerization . Th e washe d monomer s ar e mixe dwit hrecycle dmonomers , modifiers , activators , soa p solutio n(emulsifier) , an dcatalys t andcharge dint o a j polymerizatio nreacto r (Ste p 2) . Atypica l recip e fo r emulsio n i SB Ri s presente di nTabl e 12 . Polymerizatio nproceed s i na \ stepwis e fashio nthroug ha chai no f reactor s tha t allo wth e

facilit ya hig hdegre e o f flexibilit yi nproducin g differen t grade s o f SBR . Eithe r a ho t (50°C ) o r a col d(4*C ) proces s ma y b e used . Th e reactio ni s normall ycarrie dou t t o a 6 0 percen t monome r conversio nafte r whic ha shortsto p solutio ni s adde dt o preven t furthe r polymerization . Th e late xreactio nmixtur e i s sen t t o a vacuumflas htan k fo r recover yo f unreacted-butadien e an dthe nt o a steam

strippin g uni t fo r th e recover yo f unreacte d styren e (Ste p 3) . Afte r th e monome r i s removed , th e late xma y tak e on e o f tw o routes . I non e route , SB Relastome r i s forme d throug hemulsio nbreakin g an ddryin g steps . Th e strippe dlate x i s transferre dt o a blendin g an dstorag e tan k wher e a n antioxidan t i s adde dt o preven t th e polyme r fromreactin g wit h oxyge no r ozon e (Step 4) . Th e late xstreami s the npumpe dint o coagulatio ntank s wher e th e emulsio ni s broke n(Step 5) . An acid-brin e mixtur e (aluminu m sulfate ) i s adde dwhic hcause s th e rubbe r (knowna s crumb ) t o precipitat e out . Th e rubbe r copolyme r i s the nsen t t o a washin g anddryin g sectio n(Step 6 ) an dpresse d int o bales. 11 

### ' 1 2 

### Th e secon droute , whic hproduce s styren e butadien e late xa s th e en dproduct , include s th e sam e step s a s th e elastome r productio nexcep t fo r th e late xcoagulatio nandfina l rinsing , dryin g an dbaling . However , i nsom e instance s th e late x polymerizatio nreactio nma yb e continue dt o a 9 8 o r 9 9 percen t conversion—a s oppose dt o 6 0 percen t conversio nfo r emulsio n crumbrubber . Therefore , i nthes e instances , th e monome r recover ystep s ar e omitted . Th e late xproduc t i s als o passe d

6 0P.7 2

TABL E 12 . TYPICAL RECTP wrwr , TM „ KfaCIP E FO REMULSIONSBR Component s Butadien e Styren e d-Isopropy l Benzen e Hydroperoxid e Ferrou s Sulfat e Tert-Dodecy l Mercapta n Potassiu

mPyrophosphat e Rosi n Aci d Soa p Wate r Source : Referenc e 11 . -££i2htPercen t 2 5 1 0

< 0 < 0 0 . 0 . 1 . 6 3 . 0

. 0

. 1

. 1 1 1 4

. 0 Functio n

Monome r Monome r Catalys t Activato r Modifie r Buffe r Emulsifie r

<> lP.7 3

throug ha serie s o f scree nfilter s (Step 7 ) t o remov e larg e solid s befor e i t i s sen t t o th e blendin g tan k fo r storag e (Step 8). 1 1 ' " Solutio n Process- — Aflo wdiagramfo r th e solutio nproces s i s showni n Figur e 10 . I n thi s process , polymerizatio n take s plac e i na n organi c solven t medium , usuall yhexane . Freshl ywashe d (Step 1 ) an d recycle d styren e and butadien e monomer s and th e organi c solven t ar e pumpe d throug hdryer s t o remov e an ywate r (Step 2) , the n blende d togethe r t o form th e mixe d feed . Th e fee d mayb e sen t t o a drye r a s wel l (Step 3 ) t o remov e anyresidua l trace s o f water . Th e mixtur e i s adde d t o th e polymerizatio nreacto r alon g wit ha catalys t (Step 4) . Polymerizatio n take s plac e througha serie s o f reactor s and proceed s t o greate r tha n 9 0 percen t conversion . Ashortsto p solutio n i s adde d t o hal t furthe r polymerization . Th e reactio n produc t i s i n th e form o f rubbe r cement . I t i s pumpe d t o produc t storag e (Step 5 ) wher e i t i s washe d t o remov e catalys t and the n a n antioxidan t and othe r desire d chemical s suc ha s oil s and filler s ar e added . Th e rubbe r cemen t i s pumpe d t o a coagulato r (Step 6 ) wher e th e rubbe r i s precipitate d i n crum bform . Unreacte d monomer s and solven t ar e recovere d b

ysteamstripping . Th e strippe d rubbe r cemen t slurry i s sen t t o a washin g an d dryin g sectio n(Step 7 ) wher e i t i s separated , washed , and the n passe d througha nextrude r fo r dewaterin g an

d drying . Th e drie d rubbe r i s bale d and stored."•• " Emission s Th e emissio n source s a t a nS B copolyme r facilit yar e typica l o f thos e commo n t o chemica l productio n facilities : proces s vents , ope n proces s equipment , equipmen t leaks , storag e tank s and transfe r operation s and secondar yemission s fromth e handlin g and disposa l o f wastes . Styren e ma yals o b e emitte d durin g accidenta l o r emergenc yreleases . 

### 6 2Monome r

Was h 

## ©

C J 

# ©

Monome r Dryin g Recycle d Monomers an d Solven t



# © ©

Fee d Dryin g Strippe r

Solven t 

## © Reactors

Catalyst 

## © Rubbe rCemen t Was h

Shortsto p Antioxidant ,

Oils , Fillers 

# ©

Coagulatio n an d Stea m Strippin g 

# M Washin g an d

Dryin g SB R

-* - Elastome r

Denote s potentia l locatio n o femissio n source Fugitive s fro m overal l proces s Secondarysources Storag e an d loadin g losses 

### Figur e 10 . SBr

tProductio n b

ySolutio n Polymerizatio n1 1P.7 5

Emission s fro mproces s vent s and ope nequipmen t occu r fro m reactors , recover ycolumns , blend and coagulatio n tanks , filte r screens , dryer s and othe r proces s vessels . The ymayoccu r continuousl y(froma continuou s process ) o r intermittentl y(from a batc hprocess) . Polymerizatio n reactor s fo r bot hemulsio n and solutio n processe s ar e normall yseale d usin g ruptur e discs , wit h venting t o a flar e durin g rare , extrem e upse t conditions . Mos t o f th e styren e emitte d during th e emulsio ncrum bproces s occur s byevaporatio n fromope n blen d and coagulatio ntank s and from drye r vents . A n estimate d 7 8 percen t o f tota l VO C emission s (mostl ystyrene ) fro mth e emulsio n crum bproces s ar e emitte d during th e copolyme r dryin g steps. 1 4 An emissio nfacto r fo r th e dryin g ste p i n SB Remulsio npolymerizatio n i s give n i n Tabl e 13 . Emissio n dat a fo r othe r proces s source s ar e no t available. 1 5 I n th e S B late xproductio nprocess , th e late xi s strippe d o f unreacte d monomer s and passe d throughshake r screen s t o remov e larg e agglomerate d solids . Thes e screen s ar e ope nt o th e atmosphere , bu t emission s ar e estimate d t o b e verylow . Concentration s o f 2 5 ppmstyren e (an d 3 9 ppmbutadiene ) hav e bee n measure d abov e th e screens , bu t th e ai r flo wrat e coul d no t b e determined. i a

T o contro l proces s ven t emissions , th e proces s stream s ca n b e route d t o a flar e o r blowdow n tank . Recovere d styren e emission s fromth e vacuumdistillatio ncolumnar e recycle d wit h the reacto r fee d stream . Wher e feasible , ope n equipmen t mayb e enclosed. 6 Source s o f fugitiv e emission s ar e liste d i nSectio n4 . Als o provide d i s a descriptio no f th e procedur e fo r estimatin g emission s an

d a tabl e o f contro l option s and efficiencies . A t thes e facilitie s th e majo r sourc e o f ai r emission s o f styren e occur s fromstyren e transfe r durin g th e unloadin g o f trucks , tank car s and barge s an d th e fillin g o f th e monome r storag e tanks . N o S B copolyme r facilitie s ar e knownt o hav e 

### 6 4P.7 6

installe d contro l device s t o reduc e o r captur e thes e emissions. * Losse s o f styren e fromstorag e tank s als o occu r du e t o norma l tank breathin g processes . Uncontrolle d emissio nfactor s fo r breathin g and fugitiv e losse s o f styren e fromstorag e tank s ar e presente d i n Tabl e 13. " STYRENE-ACRYLONITRIL E PRODUCTION Styrene-acrylonitril e copolymer s ar e noncrystalline , linea r resins . The yar e characterize d bygoo d hardness , rigidity , dimensiona l stability , hig hhea t deflectio ntemperatures , and chemica l resistance. 1 Acrylonitril e provide s th e chemica l resistanc e and hea t stability , and styren e provide s rigidit yand processin g ease . Adiversit yo f SA Nspecialt ygrades, includin g UV-stabilized , antistat , barrier , and weatherabl e grade s ar e available. 1 7 Th e styren e conten t o f SA Nrange s from6 5 t o 8 5 percent. 6 ' 17 ' 1 8 Th e majorit yo f SA Nmanufacture d i s use d captivel yt o produc e acrylonitrile-butadiene-styren e resins . SA Nals o ha s a wid e rang e o f application s i nth e automotive , housewares , electronics , appliances , an d packagin g marketing areas . SA Ni s use d i n automotiv e trim , marin e instruments , tracto r components , coffe e filte r funnels , instrumen t panel s o nappliance s and automobiles , boa t hulls , swimming poo l components , cassett e parts , syringes , dentures , toothbrus hhandles , blende r bowls , an d vacuu mcleane r parts . Mos t o f th e SA Nsol d i nth e Unite d State s i s use d fo r injectio n moldin g a s a replacemen t fo r polystyrene. 1 9 Onl ytw o companie s produc e SA Nexclusivel yfo r sal e o nth e market . Thes e facilitie s and thei r annua l capacitie s ar e liste d i n Tabl e 14 . SA

Ni s als o produce d a t al l AB S facilities , a s a ste p i n th e manufactur e o f ABS. 5 Les s tha nfou r percen t o f styren e productio n i n th e Unite d State s i s use d i n th e manufactur e o f SA

Nfo r direc t sale. 2 0



### 6 5TABL E 13 . EMISSIONFACTOR S FO RSTYRENE-BUTADIEN E PRODUCTION Emissio n Rat e Industria l Proces s Emissio n

Sourc e (K

g Styrene / Mg Resin ) (LbStyrene /

To nResin ) Contro l

Statu s SBR-emulsio n Drying 0. 6 1. 2 Uncontrolle d SBR-emulsio n SBR-emulsion / solutio n Storag e tank

(fugitive ) Storag e tank (breathing ) 0. 4 0.0 2 0. 8

0.0 4 Uncontrolle d

Uncontrolle d

<f> Source : Referenc e 12 .

^ i ^ iP.7 8

TABL E 14 . STYRENE-ACRYLONITRIL E PRODUCTIONFACILITIE S

Company * Do w Monsant o Locatio n

Midland , M I Addyston , O H TOTAL Annua l

(Mg/yr ) 31,75 1 22.67 9 54,431 b Capacit y

(M Mlb/yr ) 7 0 5 0 12 0 'Onl ythos e producer s wh o manufactur e SA Nfo r sal e o n th e merchan t marke t ar e listed . Al l AB S resin s producer s hav e SA N resi n productio n capacity . "Number s d o no t tota l du e t o rounding . NOTE : Thi s listing i s subjec t t o chang e a s marke t condition s change , facilit yownershi p changes , plant s ar e close d down , etc . Th e reade r shoul d verif yth e existenc e o f particula r facilitie s byconsultin g curren t listing s and/o r th e plant s themselves . Th e leve l o f styren e emission s froman ygive n facilit yi s a functio n o f variable s suc ha s capacity , throughput , and contro l measures , and shoul d b e determine d throug hdirec t contac t wit hplan t personnel . Thes e operatin g plant s and location s wer e curren t a s o f Januar y1990 . Source : Referenc e 5 .



### 6 7P.7 9

Proces s Description s SA Nresin s ma yb e produce d b yemulsion , suspension , o r continuou s mas s polymerization . Th e majorit yo f SA Nfo r captiv e us e i s produce d usin g emulsio n polymerization . SA Nfo r sal e i n th e marketplac e i s mos t ofte nproduce d bymas s polymerization. 3 1 Emulsio n Process — SA Nproductio nb

yemulsio npolymerization , showni n Figur e 11 , mayb e conducte d i n eithe r a batc ho r a continuou s mode. 2 ' 11 ' 1 8 Th e batc hproces s i s mor e commonl yused»_ 20

_I nbot h processes , styren e and acrylonitril e monomer s ar e pumpe d int o a monomer-makeup tank alon g wit hrecovere d acrylonitril e an d chemica l additive s (Step 1) . Th e monome r mi xi s fe d int o th e polymerizatio n reacto r wit hemulsifier , initiator , chain-transfe r agen t and deionize d wate r (Step 2) . Copolymerizatio n i s carrie d ou t i n th e temperatur e rang e o f 70-100° C (160-212°F ) an d proceed s t o 90-9 8 percen t conversion. 2 1 Th e polymerizatio ntemperatur e ma yb e reduce d t o a s lo wa s 38° C (100°F ) i f redo xcatalysi s system s ar e used . Afte r a suitabl e retentio ntim e i nth e reactor , th e SA

Ncopolyme r mel t (latex ) i s pumpe d t o a stea m strippe r fo r recoveryo f unreacte d monomer s (Step 3) . Th e copolyme r late xmayb e use d directl yi nth e productio no f AB S resin , o r i t mayb e sen t t o a coagulatio nand flocculatio n sectio n (Ste

p 4) . Th e polyme r i s filtere d (Step 5 ) the n washed , and drie d (Step 6 ) t o produc e th e soli d SA Ncopolymer. 2 Dyes , antioxidant s an

d othe r additive s mayb e mechanicall yblende d int o th e copolyme r usin g extruder s and rollin g mill s (Step 7) . Polyme r sheet s from thes e operation s ar e the n pelletize d and packaged .



### 6 8V

O Recycled Monomer s 

# © ©

Monome r Make-U p 

## © Polymerizatio n R < leacto r 

## ©

Styrene , Acrylonitrile , Additives Emulsifier, Initiator , Chai n Transfe rAgent , Wate r 

# ©

Stea m Strippe r 

## © 

# ©

Coagulation , Flocculatkw i 

## ©

AB S Productio n Filters 

## © Washin g an d Dryin g 

## ® 

# ©

3lendlng , Milling , Compoundin g 

## ©

Denotes potentia l locatio n o femissio n source Fugitives fro m overal l proces s Secondarysources Storag e an d loadin g losses Figure 11 . Productio n ofSA N byEmulsio n Polymerization 2 1P.8 1

Suspensio n Process — SA Nproductio n b

ysuspensio npolymerizatio nmayb e conducte d i n eithe r batc ho r continuou s mode. 2 ' 11 ' 1 8 Abloc k flo wdiagram fo r th e suspensio n proces s i s give ni n Figur e 12 . Styren e and acrylonitril e monomer s ar e fed int o a pressur e reacto r an d mechanicall ydisperse d i n wate r containin g catalyst s an d suspending agent s (Step 1) . Th e wate r function s t o remov e hea t and contro l particl e size . Equa l amount s o f monome r and wate r ar e used. 1 9 Whil e suspende d b yagitation , th e monome r droplet s copolymeriz e formin g insolubl e bead s o f polymer . Th e temperatur e o f th e polymerizatio n reacto r range s from60-150° C (140-300°F) . Amonome r conversio no f 9 5 percen t i s normall yachieved . Th e polyme r slurryi s pumpe d t o a centrifug e fo r washin g and dewaterin g (Step 2) . Th e polyme r i s sen t t o a flas htank an d steamo r vacuu

mstripper ' fo r recoveryo f unreacte d monomer s (Step 3) . Th e soli d and liqui d phase s o f th e polyme r slurryar e separate d b

ycentrifugatio n and/o r filtratio n(Step 4) . Th e soli d phas e i s the n drie d i na rotarydrye r (Step 5) . Th e drie d SA Ni s finishe d bymechanicall yblendin g i n dyes , antioxidant s and othe r additives . Th e polyme r sheet s ar e the n pelletize d and package d (Step 6). 7 ' 8 Thi s suspensio n proces s i s simple r tha nth e emulsio n proces s a s n o coagulatio n and flocculatio nstep s ar e required . Continuou s Mas s Process — Th e continuou s mas s process , showni nFigur e 13 , i s a self

containe d syste mtha t doe s no t requir e emulsifiers , suspending agents , salts , o r water . Solvent s ar e use d t o contro l th e viscosity . I n Ste p one , styren e and acrylonitril e monomer s ar e heate d togethe r wit hmodifier-solven t and pumpe d continuousl y int o th e agitate d polymerizatio n reacto r maintaine d a t abou t 27 5 kP a (4 0 psia ) and 100-200' c (212-390°F) . Catalys t i s adde d and reactio n 'proceed s t o 2 0 percen t conversion . Th e polyme r i s passe d througha serie s o f devolatilizer s t o remov e unreacte d



### 7 0Styrene , .

Acrylonitril e Recycle d Monomers

L * Polymerizatio n

Reacto r_ 

## ©

Water , Catalysts , Suspendin g Agents 

# ©

Washin g an d Dewaterin g 

## © 

# ©

Flas h Tan k an d Strippe r 

## © Filters 

## © Drye r 

## © ^lending , MilllngJ Compoundin g 

## ©

Denotes potentia l locatio n o femissio n source Fugitives fro m overal l proces s Secondarysource s Storag e an d loadin g losses

Figure 12 . Productio n o fSA N bySuspensio n Polymerization 2 1NJ Styrene , Acrylonitrile , Modifer-Solvent Recycle d Monomers an d Modifier-Solven t 

# ©

Polymerizatio n Reacto r 

## ©

Catalyst 

# 0

Devolatilizers 

## © 

# 0

Blending , Milling , Compoundin g 

## ©

Denotes potentia l locatio n o femissio n source FugKrves'fro m overal l proces s Secondarysource s Storag e an d loadin g losse s 

### Figur e 13 . Productio n o

fSA N b yContinuou s Mass Polymerizatio n 2 1P.8 4

monomer s and ' modifier-solven t (Ste p2) . Devolatilizationoccur s unde r vacuu

m a t a temperatur e rangingfro m 120-260° C (248-500°F) . Inerts , unreactedmonomer s an dmodifier-solven t ar e removed overheadfro

m the devolatilizers . The overhead s ar e th e condensedan

dpassedthrougha refrigeratedstyren e scrubbe r t o recove r monomer s an dmodifier-solven t whic har e recycle dt o the feedtanks . Th e bottoms fro m the fina l devolatilize r ar e almos t pur e polyme r melt . Th e polyme r mel t i s pumpedthroughan extruder , cooledan dchoppe dint o pellet s (Step3). 2,11,i a Eji H salon s Facilitie s manufacturingSA N emi t styrene fro

m proces s equipmen t vents , openproces s equipment , equipmen t leaks , storag e tankvents , secondary sources , an

dtransfe r andhandling operations . No emission s dat a fo r an y o f thes e source s ar e available . Proces s equipmen t source s include monome r make-uptanks , polymerizationreactors , monome r strippers , devolatilizers , coagulation/flocculationstages , dewatering/dryingstages , an d blending/compoundingoperations . The emission s wil l vary accordingt o the typ e o f polymerizationproces s use dan dth e exac t monome r mix . A s describedunde r styrene-butadiene copolyme r production , proces s ven t emission s may b e controlledb

y routingth e streams t o a flar e o r blowdown . Currently , neithe r SA N facilit y

ha s control s t o captur e o r preven t styrene emission s fro m transfe r operations . ACRYLONITRILE-BUTADIENE-STYRENE COPOLYMERPRODUCTION Acrylonitrile-butadiene-styrene resin s ar e produce db y graftingstyrene-acrylonitril e copolyme r ont o a rubbe r an dthen blendingthe graftedrubbe r wit hSAN. 2 3 Polybutadien e i s

7 2P.8 5

monomer s and modifier-solven t (Ste p 2) . Devolatilizatio noccur s unde r vacuu

ma t a temperatur e rangin g from120-260° C (248-500°F) . Inerts , unreacte d monomer s and modifier-solven t ar e remove d overhea d fromth e devolatilizers . Th e overhead s ar e th e condense d an

d passe d througha refrigerate d styren e scrubbe r t o recove r monomer s and modifier-solven t whic har e recycle d t o th e fee d tanks . Th e bottom s from th e fina l devolatilize r ar e almos t pur e polyme r melt . Th e polyme r mel t i s pumpe d throug ha n extruder , coole d and choppe d int o pellet s (Step 2) A'11 '" Emission s Facilitie s manufacturin g SA Nemi t styren e from proces s equipmen t vents , ope nproces s equipment , equipmen t leaks , storag e tank vents , secondarysources , and transfe r an d handlin g operations . N o emission s dat a fo r an yo f thes e source s ar e available . Proces s equipmen t source s includ e monome r make-up tanks , polymerizatio n reactors , monome r strippers , devolatilizers , coagulation/flocculatio n stages , dewatering/dryin g stages , and blending/compoundin g operations . Th e emission s wil l var y according t o th e typ e o f polymerizatio nproces s use d and th e exac t monome r mix . A s describe d unde r styrene-butadien e copolyme r production , proces s ven t emission s mayb e controlle d b yrouting th e stream s t o a flar e o r blowdown . Currently , neithe r SA Nfacilit yha s control s t o captur e o r preven t styren e emission s fromtransfe r operations . ACRYLONITRILE-BUTADIENE-STYRENE COPOLYME RPRODUCTION Acrylonitrile-butadiene-styren e resin s ar e produce d b y graftin g styrene-acrylonitril e copolyme r ont o a rubbe r and the n blendin g th e grafte d rubbe r wit hSAN. 2 3 Polybutadien e i s normall yuse d a s th e backbon e o r substrat e rubber , bu t nitril e 7 3P.8 6

rubber s and SB Rar e als o used . Th e resultin g polyme r ha s thre e phases : continuou s matri xo f SAN , disperse d phas e o f polybutadien e o r othe r rubber , and boundar ylaye r o f SA Ngraft. 2 2 Th e SA Ngrafte d rubbe r provide s adhesio nbetwee n SA Nand th e rubbe r whic hwoul d hav e bee nincompatible . AB S possesse s th e usefu l propertie s o f SAN , suc ha s rigidit y and resistanc e t o chemical s and solvents , whil e th e rubbe r additiv e impart s impac t resistance. 2 AB S resin s ar e produce d wit ha wid e rang e o f propertie s tha t ar e tailore d t o specifi c applications . Th e difference s i napplicatio n ar e achieve d b y changin g th e relativ e concentration s o f th e thre e monomer s and by usin g additives . Ove r 7 5 grade s o f AB S ar e available , including glas s reinforced , UV-resistant , flame retardant , foamable , and electroplatin g grades. a3 ' 24 ' 2 S Th e resin s ar e markete d i npowde r formo r a s natura l and precolore d pellets. 3 2

AB S resin s ar e use d t o mak e plasti c component s fo r a variet y o f product s suc ha s automotiv e parts , pipe s an d fittings , appliances , telephones , busines s machines , toy s and sporting goods . Th e majo r us e fo r AB S i s i n th e automotiv e industry , wher e th e resin s ar e injectio nmolde d t o mak e interio r tri m components , consoles , instrumen t pane l tri mgrill s an d whee l covers . Currentl yAB S resin s ar e produce d b ythre e companie s a t te n location s i n eigh t States . Thes e facilitie s and thei r productio n capacitie s ar e liste d i n Tabl e 15 . Thes e te nfacilitie s als o produc e SA

Na s a ste p i n th e manufactur e o f ABS . Industry-wid e AB S capacit yfo r 199 0 i s abou t 790,15 8 Mg/y r (174 2 MMlbs). 5 Manufactur e o f AB S and SA Nresin s consume s 9 percen t o f u . S . styren e production. 6



### 7 4P.8 7

TABL E 15 . ACRYLONITRILE-BUTADIENE-STYREN E PRODUCTIONFACILITIE S

Compan y Diamond Polymer s Do w

Genera l Electri c

Monsant o Locatio n Akron , O H Gale s Ferry , C T Ironton , O H Midland , M I Torrance , CA Ba ySt . Louis , M S Ottawa , I L Washington , W

V Addyston , O H Muscatine , I A TOTA L Annua l (Mg/yr ) 9,97 9 27,21 5 36,28 7 68,03 9 18,14 4 95,25 4 136,07 8 158,75 7 145,15 0 95.25 4 790,15 8 Capacit y

(M Mlb/yr ) 2 2 6 0 8 0 15 0 4 0 21 0 30 0 35 0 32 0 21 0 1,74 2 NOTE : Thi s listin g i s subjec t t o chang e a s marke t condition s change , facilit yownershi p changes , plant s ar e close d down { etc . Th e reade r shoul d verif yth e existenc e o f particula r facilitie s b yconsultin g curren t listing s and/o r th e plant s themselves . Th e leve l o f styren e emission s froman ygive nfacilit yi s a functio n o f variable s suc ha s capacity , throughput , and contro l measures , and shoul d b e determine d throughdirec t contac t wit hplan t personnel . Thes e operatin g plant s and location s wer e curren t a s o f January1990 . Source : Referenc e 5 .



### 7 5P.8 8

Proces s Description s AB S resin s ma yb e synthesize d b yemulsion , suspension , and continuou s mas s (bulk ) polymerization . Th e majorit yo f productio n i s b

ybatc hemulsion . Specialize d resin s ar e produce d bysuspensio n polymerization . Emulsio nand suspensio n polymerization s ar e base d o na n aqueous-phas e reaction . I n contrast , th e continuou s mas s process , th e newes t technology , doe s no t procee d i n water . Therefore , dewaterin g and polyme r dryin g ar e no t require d and wastewate r treatmen t i s minimized. 2 3 Emulsio n Process —- -. _ Abloc k diagramshowin g tw o route s bywhic hAB S i s produce d usin g th e emulsio n proces s i s presente d i n Figur e 14 . Thi s proces s i s referre d t o a s th e ABS/SA Nproces s becaus e SA Ni s prepare d i n a sid e ste p and mixe d wit hgraf t ABS . Th e emulsio n proces s involve s thre e distinc t polymerizations :

polymerizatio no f butadien e t o formpolybutadiene ; grafting o f styren e an d acrylonitril e monomer s t o th e polybutadien e substrate ; an d copolymerizatio n o f styrene-acrylonitrile . Butadien e monome r i s converte d t o polybutadien e late x (Step l ) an

d the n pumpe d int o th e AB S reacto r wit hstyrene , acrylonitrile , emulsifier s and initiator s (Step 2) . Th e styren e and acrylonitril e monomer s ar e grafte d t o th e polybutadien e late x substrat e i n eithe r a batc ho r continuou s process . Reactio n conversio n i s 9 0 t o 9 5 percent . Vapor s fromth e reacto r ar e usuall yvente d t o a n acrylonitril e absorber . Th e absorbe r emission s ar e usuall yvente d t o th e atmospher e o r incinerated . Th e graf t AB S i s the ntransferre d t o a coagulato r (Step 3) . SA N



### 7 6Polybutadien e Reacto r~ . 

## © AB S Late x Reactor- . 

## © Styren e Acryonitrile , Emulsifier

s an d Initiator s

Stryene , Acrylonitrile , Emulsifiers , Catalysts , Wate r 

# 0

Coagulator . ?—T

SA N

SA N Resi n Reacto r ( 8 

## © Scree i 

# fe

Steam , Antioxidant , Coagulan t

Coagulato r 

## © Centrifug e



## ©

Additives , Antioxidants , • Dyes

Alternativ

e SA N Pat h 

# 0

Vacuu m Filtratio n 

## ©

Mechanica l Blendin g 

## ©

• > Dewaterln g < $ Packagin g 

## ©

Denotes potentia l locatio n o femissio n source Fugitives fro m overal l proces s Secondar ysources Storag e an d loadin g losses 

### Figur e 14 . Productio n o

fABS/SA N b

yEmulsio n Polymerizatio n nP.9 0

copolyme r i s prepare d i n a separat e sid e ste p (Step 8 ) (se e proces s description s unde r SA Ncopolymer s i n thi s section) . Th e graf t AB S and th e SA Nmayb e mixe d togethe r a t eithe r o f tw o point s i n th e emulsio n process . Th e SA Nlate xma yadde d t o th e graf t AB S late xi n th e AB S coagulato r (Step 3) . Th e agglomerate d polyme r i s dewatere d byscreenin g (Step 4) , centrifugin g (Step 5) , and vacuumfiltratio n(Step 6) . N o dryin g ste p i s required . However , som e facilitie s emplo ya drye r i n plac e o f th e centrifug e and vacuumfilter . Th e AB S i s sen t t o a finishin g sectio n wher e dyes , antioxidants , and othe r additive s ar e mechanicall yblende d i n(Step 7) . Alternatively , th e SA Nlate x ma yb e pumpe d int o a nSA Ncoagulato r (Step 8 ) and sent , t o a dewaterin g sectio n (Step 10 ) separately . Th e soli d SA Ni s the n mechanicall ymixe d wit hsoli d graf t AB S a t th e finishin g stag e (Step 7) . Th e polyme r sheet s ar e cu t int o pellet s and package d (Step ll). 2 -"' " I n a thir d rout e (no t shown ) SA Ngraf t and styrene acrylonitril e copolymerizatio n occu r i nth e sam e reactio nvessel . Th e resulting AB S late xi s coagulated , washed , filtere d and dried . Suspensio n Process — Abloc k flowdiagramo f th e suspensio nAB S proces s i s shown i n Figur e 15 . Thi s proces s begin s wit hpolybutadien e rubbe r whic hi s s o lightl ycros s linke d tha t i t i s solubl e i n th e acrylonitril e an

d styren e monomers . Th e polybutadien e i s firs t dissolve d i n styren e and acrylonitril e monomer s t o produc e a solutio n fre e o f crosslinke d rubbe r gel s (Step 1) . Th e solutio n i s pumpe d int o a prepolymerize r wher e a free-radica l initiato r i s adde d along wit hchain-transfe r agent s i na prepolymerize r (Step 2) . Afte r 2 5 t o 3 5 percen t monome r conversion , th e polyme r syrup i s transferre d t o a suspensio n reacto r wher e i t i s disperse d i n wate r byagitatio n(Step 3) .



### 7 8Styrene ,

Acrylonitril e

1 0 

# © 0

Rubbe r Dissotver 

## ©

Polybutadien e Rubbe r Pre Polymerlze r 

## ©

Initiator s an d Chai n Transfe rAgents 

# ©

Suspensio n Reacto r 

## ©

Suspendin g Agent , Wate r 

# ©

Dewaterin g 

## © 

# © B J Drye r 

## © Product Storag e 

## ©

Denotes potentia l locatio n o femissio n source \ Fugitives fro m overal l proces s Secondarysources Storag e an d loadin g losses

Figure 15 . Productio n o fAB S bySuspensio n Polymerizatio n 1 1P.9 2

Afte r achievin g th e desire d monome r conversion , th e product s ar e transferre d t o a washing/dewaterin g syste m(Step 4) , usuall y a continuou s centrifuge . Th e polyme r bead s ar e the nsen t t o a ho t ai r drye r (Step 5) . Th e drie d finishe d bead s ar e transferre d t o produc t storag e (Step 6). 2 '"' 1 8 Continuou s Mas s Process— ' • Abloc k flo wdiagramfo r th e continuou s mas s AB S proces s i s shown i n Figur e 16. " Unlik e emulsio nand suspensio n polymerization , thi s polymerizatio nproces s doe s no t procee d i n water . Alightl ycross-linked , monomer-solubl e for m o f polybutadien e i s dissolve d i n styren e an d acrylonitril e monomers , alon g wit hinitiator s and modifier s (Step 1) . Th e mixe d fee d i s pumpe d int o a prepolymerizer , i n whic ha conversio nreactio n cause s th e AB S rubbe r t o precipitat e ou t o f solutio n(Step 2) . Whe n monome r conversio nreache s abou t 3 0 percent , th e resultin g syrup i s transferre d t o th e bul k polymerize r wher e monome r conversio n i s continue d t o betwee n 5 0 t o 8 0 percen t (Step 3) . Th e polyme r mel t i s sen t t o a devolatize r (Step 4 ) wher e unreacte d monome r i s remove d unde r vacuum . Th e monome r vapor s ar e condense d and recycle d t o th e prepolymerizer . Th e AB S polyme r i s the n passe d througha nextruder , coole d i n a wate r bat h(Step 5) , and choppe d int o pellet s (Step 6). 2 ' 11 ' 1 8 Emission s Informatio n i s availabl e o n acrylonitril e and butadien e emission s from1 0 AB S productio nfacilities . Althoughstyren e emission s wer e no t reporte d separatel ybyanyo f th e facilities , thre e facilitie s liste d "othe r VOC " emissio n estimates , o f whic h th e majo r componen t i s likel yt o b e styrene . Thes e VO C emission s wer e attribute d t o proces s vent s frompolymerizatio n reactors , coagulation/washin g steps , dewatering , intermediat e proces s tanks , and compounding. 2 3 Significan t styren e emission s resul t primaril yfromunloadin g styren e fromtan k truck s an d barge s and

8 00 0 Acrylonitrile , Initiators , Styren e Modifier

s

Polybutadien e Rubbe r 

# 0

Rubbe r Dissolve r 

## © 

# ©

Pre polymerize r 

## © Monome r Recycl e Condenso r 

# ©

Bul k Polymarke r 

## © A

Devolatilize r 

## © 

# ©

Extruder / Wate rBat h 

## © Pelle

tize r 

## ©

Fugitive s fro m overal l process Secondar ysource s Storag e an d loadin g losses Denote s potentia l locatio n ofemissio n source § Figure 16 . Productio n o fAB S byContinuou s Mas s Polymerizatio n * 'P.9 4

fillin g th e storag e tank. 6 I naddition , som e emission s ar e possibl e from

secondarysource s an d emergenc yand accidenta l releases . Insufficien t informatio n i s availabl e t o develo p emissio n factor s fo r fugitive s o r proces s emissio n sources . Th e emissio n point s varydependin g upo nth e typ e o f polymerizatio n proces s used . Th e emulsio n proces s ha s th e highes t emission s whil e th e continuou s mas s proces s ha s inherentl ylo wemissions . I n addition , styren e emission s ma y varyfrom

plan t t o plan t depending o n produc t mix . Manufacturer s o f AB S resin s hav e take n tw o basic-approache s t o contro l som e o f th e A Nproces s vents : hig hmonome r conversio n technology(HMCT ) and therma l oxidation . Thes e technique s woul d als o contro l styren e emissions . Th e hig hmonome r conversio ni s achieve d usin g a second reacto r th e sam e siz e a s th e firs t reacto r wher e conversio ni s increase d t o around 9 8 percent . Th e HMC T require s tha t th e second reacto r and a n absorbe r b e installe d a t th e polyme r filte r step . Therma l oxidatio ni s applicabl e t o al l type s o f AB S processes . I n thi s approac h emissio n vent s ar e tie d int o on e o r mor e combustio n devices . Thes e device s ma yb e part s o f steamgenerators , incinerator s o r flares. 2 3

UNSATURATE D POLYESTE RRESI NPRODUCTION Thermose t polyeste r resin s ar e comple xpolymer s resultin g fromth e cross-linkin g reactio no f a liqui d unsaturate d polyeste r wit ha viny l typ e monomer , mos t ofte nstyrene . Th e unsaturate d polyeste r i s forme d fromth e condensatio nreactio no f a n unsaturate d dibasi c aci d o r anhydride , a saturate d dibasi c aci d o r anhydride , and a polyfunctiona l alcohol . Tabl e 1 6 list s th e mos t commo n compound s use d fo r eac hcomponen t o f th e polyeste r "backbone, " alon g wit hth e principa l cross-linkin g monome r styrene . Th e chemica l reaction s tha t formbot hth e unsaturate d

8 2P.9 5

TABL E 16 . TYPICAL COMPONENT S USE D T O FORM UNSATURATE D POLYESTE RRESIN S

Unsaturate d Acid s Saturate d

Acid s Polyfunctiona l

Alcohol s Cross-Linke d Agen t (Monomer ) Malei c anhydrid e Fumari c aci d Phthali c anhydrid e Isophthali c aci d Adipi c aci d Propylen e glyco l Ethylen e glyco l Diethylen e glyco l Dipropylen e glyco l Neopenty l glyco l Pentaerythrito l Styren e

Source : Referenc e 27 .

8 3P.9 6

.i- 

### | polyeste r an dth e cross-linke dpolyeste r resi nar e show ni n ] Figur e 17. 2 7



### I norde r t o b e use di nth e fabricatio no f products , th e \ liqui dresi nmus t b e mixe dwit ha catalys t t o initiat e : polymerizatio nint o a soli dthermoset . Catalys t concentration s

generall yrang e fro m1 t o 2 percen t b yorigina l weigh t o f resin ; withi ncertai nlimits , th e highe r th e catalys t concentration , th e faste r th e cross-linkin g reactio nproceeds . Commo ncatalyst s ar e organi c peroxides , typicall ymethy l ethy l keton e peroxid e o r benzoy l peroxide . Resin s ma ycontaininhibitors , t o avoi dsel f curin g durin g resi nstorage , an dpromoters , t o allo w polymerizatio nt o occu r a t lowe r temperatures. 2 7 

### Unsaturate dpolyeste r resin s (UPR ) ar e produce dby2 3 companie s a t 5 6 location s i nth e Unite dState s a s show ni n Tabl e 17 . Productio ncapacit yfo r thes e facilitie s wa s no t found i nth e literature . Althoug hstyren e i s no t th e onl ymonome r tha t ma yb e use da s a cross-linkin g agent , i t i s th e mos t common . I n 1988 , tota l UP Rproductio ni nth e Unite dState s wa s 768,85 2 M g (169 5 M Mlbs). 6 

### UP Ri s a thermose t resi nuse di nconstructio n (tub s andshowers) , marin e andmarin e accessorie s (boats , boa t accessories) , castin g (culture dmarbl e an donyx) , transportatio n (distributo r caps , aut o bodyparts) , consume r good s (appliances) , ge l coatings , surfac e protectiv e coatings , bonding/adhesives , electrica l components , andbusines s machines . Proces s Descriptio n Unsaturate dpolyeste r resin s ca nb e produce dbya fusio no r a solven t process . Ther e i s n o publishe dinformatio no nthei r relativ e capacities , however . I nth e fusio nprocess , a niner t ga s (typicall ynitrogen ) i s use dt o remov e wate r tha t i s generate ddurin g th e productio nprocess . Th e solven t proces s use s azeotropi c distillation. 4 

### Bot ho f thes e ar e batc h processes . Th e fusio nproces s consist s o f th e reactin g 8 4

### Reaction

1 - Unsaturate

d Polyeste r o o \ \/ / 

## c—o- c_ 1 1 oo n •H C = . C H + 2 n •HOH. C —CHO H + n •C —O —C - \/ Malelc Anhydrid

e Ethylene Glycol Phthatlc Anhydrid e

—C C — \/ O 

### I I O — CHj —CHy - O —C



### I H C C —O —CHj—CH^ —O 

### I C H + 2 n •HjO

Unsaturate

d Polyester 0 3 

### Reactio n 2 - PolyesterResi n 

# O Unsaturate

d + Polyester Styren e 

### o o 0 

### I I I I I I I (—CHj—CHj—O —C —CH—CH —C —O —CHr-CH — O —C 

### I H —C —H 

### I H —C - 

### I I — / 3 —C —

O —) n

( - O — C —{ 3 —C —O — CHj-CHj —O —

C —CH—CH —C — O —CHj—CHj - ) n 

### I I I O H—C— H H—C —ff ^ Cross-finke d •**& PolyesterResi n 

### Figur e 17 . Typica l Reactio n fo rUnsaturated Polyeste ran d

Polyeste rResi n Formatio n 2 7

C DP.9 8

TABL E 17 . PRODUCER S O F UNSATURATE D POLYESTE RRESIN S

Facilit y Location(s ) Th e Alph a Corporatio n America n Cyanami d Compan y Aristec hChemica l Corporatio n

Ashland Chemica l Inc .

Barto n Chemica l Corporatio n BAS F Corporatio n Baye r US AInc . B P America , Inc . Cargill , Inc .

Coo k Composite s

Do wChemica l U.S.A . Emhar t Corporatio n Th e P.D . Georg e Compan y HighJ . - Resin s Compan y IC I America n Holdings , Inc . (The Glide n Company ) Insulating Material s Inc . Collierville , T N Kathleen , F L Perris , CA Wallingford , C T Bartow , F L Colton , CA Jacksonville , AR Nevill e Island , P A Ashtabula , O H Calume t City , I L Lo s Angeles , CA Philadelphia , P A Bartow , F L Chicago , I L Detroit , M I Houston , T X Covington , KY Hawthorne ; CA Atlanta , G

A Parpentersvilie , I L Ennis , TX Fores t Park , GA Lynwood , CA Bethlehem , PA Nort hKansa s city , M O Catham , V

A Marshall , T X Saukville , W I Joliet , I L Middleton , M

A St . Louis , M O Lon g Beach , CA Columbus , G

A Reading , PA Schenectady , NY



### 8 6P.9 9

TABL E 17 . (Continued )

Facilit y Location(s ) Interplasti c Corporatio n Th e O'Brie n Corporatio n Owen' s Cornin g Fibergla s Corp . Reichhol d Chemicals , Inc .

Shere xChemica l Compan y Trinov a Corporatio n Valspa r Corporatio n (McWhorter , Inc. , subsidiary ) Minneapolis , M N Pryor , O K Sout hBend , I N Anderson , S C Valparaiso , I N Azusa , C

A Bridgeville , P A Houston , TX Jacksonvilie , F L Morris , I L Oxnard , C

A Lakeland , F L Auburn , M E Chicago , I L Rochester , PA Baltimore , M D Carpenstersvilie , I L Kankakee , I L Lo s Angeles , CA Philadelphia , PA Portland , O R NOTE : Thi s listing i s subjec t t o chang e a s marke t condition s change , facilit yownershi p changes , plant s ar e close d down , etc . Th e reade r shoul d verif yth e existenc e o f particula r facilitie s b yconsultin g curren t listing s and/o r th e plant s themselves . Thes e operatin g plant s an d location s wer e curren t a s o f January 1990 . Source : Referenc e 5 .

8 7P.10 0

(polyesterification ) and thinnin g stage s (Figur e 18) . Durin g polyesterification , dibasi c acid s suc ha s malei c and phthali c anhydrides , isophthali c acids , an d glycol s suc ha s ethylen e and propylen e glyco l ar e combine d t o forma solubl e resin . Thi s condensatio n reactio n i s carrie d ou t i na ninsulate d stainles s stee l o r glass-line d kettle . Th e mixtur e i s the nheate d t o abou t 200* C and hel d fo r 1 0 t o 2 0 hours , and wate r (by-product ) i s continuousl yremove d bybubblin g a n iner t ga s throug hth e mixture. 4 ' 2 8 Whe n th e desire d degre e o f condensatio n i s reached , th e produc t i s cooled , blende d wit hadditive s i f necessary , and transferre d t o th e thinnin g tank . I n th e thinnin g tank , styren e monome r i s combine d wit hth e coolin g unsaturate d resi nfromth e polyesterificatio n tank (Step 2) . Th e fina l produc t i s the n transferre d t o a storag e tan k (Ste p 3) . Th e solven t proces s i s simila r t o th e fusio n proces s excep t tha t instea d o f bubblin g a niner t ga s throughth e mixtur e t o remov e water , xylen e i s added . Axylene-wate r azeotrop e i s formed . Th e azeotrop e enhance s th e separatio n o f wate r vapo r by-product . Th e xylen e i nth e condense d azeotrop e i s separate d fromth e wate r and i s recycle d usin g a decante r and tw o receivers . Emission s Th e followin g informatio n i s take ndirectl yfroma 197 9 repor t prepare d fo r th e U . S . Environmenta l Protectio n Agenc y tha t estimate d and ranke d VO C emission s for'th e plastic s industry . Dat a wer e gathere d throug hliteratur e surveys , calculations , sit e visits , and questionnair e responses. * Fo r UP R productio n (bot hth e fusio n and th e solven t processes) , on e sourc e o f styren e emission s i s th e thinning tan k ven t (A) . Overhea d vapor s fromth e thinnin g operatio n ar e usuall y controlle d b

ya cooling-wate r condensor ; otherwis e the yremai n uncontrolled . Th e emissio n facto r develope d fo r th e UP Rthinnin g tan k i s shown i n Tabl e 18 . Th e author s o f Referenc e 4 estimat e 

### 8 8C O

v o PhthaJl c

Anhydrid e

Malei c Anhydrid e

Propylen e Glyco l Iner tGa s o rXylen e

Polyesteri ficatlon Reacto r 

## ©

Wate r

Styren e Monome r Storag e Produc t Blendin g Tan k 

## (£

)

Produc t Storag e 

## < D

Denote s potentia l locatio n o femissio n sourc e T o Drummin g o r Truc k Loadin g Fugitive s fro m overal l proces s Secondarysource s Storag ean d loadin g losse s Figure 18 . Unsaturate d Polyeste rResi n Productio nTABL E 18 . EMISSIONFACTOR S FO RSTYRENE FROMUP RPRODUCTIO N P. 2

Emissio n Sourc e Estimate d Emissio n Factor " (Kg/M g Resin ) (Lb/To nResin ) Thinning tan k Blending tan k Produc t storag e Monome r storag e 0.0 8 0.0 5 0.0 5 0.0 2 0.1 6 0.1 0 0.1 0 0.0 4 "Th e emissio n factor s ar e fo r fusio n and solven t processe s (whil e reacto r i s operating) . ~ - Source : Reference s 4 and 28 .

9 0P. 3

tha t th e us e o f a refrigerate d brin e condenso r o nth e thinnin g tank ven t coul d reduc e emission s by8 0 percent . Industryexpert s indicat e tha t thi s metho d i s n o longe r practice d and tha t Therma l Oxidatio n i s th e preferre d metho d today. 2 * Als o shown i n Tabl e 1 8 ar e styren e emissio nfactor s fo r UP R produc t storag e (C ) an d styren e monome r storag e (B) . Th e emissio n facto r show n fo r UP Rproduc t storag e assume s tha t th e tank s ar e equippe d wit hfixed-roo f tanks . Monome r storag e tank s ar e als o assume d t o b e equippe d wit hfixed-roo f tanks , wit ha 5 0 percen t reductio n i n styren e emission s achievabl e wit h floating-roo f tank s and/o r refrigerate d ven t condensers . MISCELLANEOU S STYRENE COPOLYME RPRODUCTION I n additio n t o th e source s o f styren e emission s previousl y discussed , styren e i s als o use d i nth e productio no f miscellaneou s product s suc ha s styrene-butadiene-vinylpyridin e (SBV ) latex , methy l methacrylate-butadiene-styren e (MBS ) resins , . an d methy l methacrylate-acrylonitrile-butadiene-styren e (MABS ) polymer . Tabl e 1 9 summarize s th e locatio no f thes e facilitie s an d thei r estimate d productio ncapacities . Availabl e detail s o f th e productio nprocesse s wil l b e provided , wher e known . Ofte n thes e detail s ar e incomplete ; therefore , reader s shoul d contac t th e facilitie s directl yfo r th e mos t accurat e information . N o informatio nwa s found i nth e literatur e abou t styren e emission s fromthes e facilities . Styrene-Butadiene-Vinylpyridin e Late x N o informatio n o n th e productio n proces s o r us e o f styrene butadiene-vinylpyridin e late xi s available . A s a copolymer , th e productio n i s likel yt o b e simila r t o tha t o f othe r copolymers .



### 9 1TABL E 19 . MISCELLANEOU S USE S O F STYREN E I NCHEMICA L PRODUCTIO N

Compan y Locatio n Ameripo l Synpo l Por t Neches , T X Produc t Styrene-butadiene

vinylpyridin e (SBV ) Late x Borg-Warne r Chemica l Co . GenCor p N J Goodyea r Goodyea r Kanek a Texa s Co . Metc o Americ a Roh m& Haa s Co . Standar d Oi l Chemica l Co . Washington , W V Mogadore , O H Akron , O H Calhoun , GA Bayport , T X Axis , A L Louisville , K Y Lima , O H Methy l Methacrylate

butadiene-styren e (MBS ) Resins " SB V Late x SB V Late x SB V Late x MB S Resin s MB S Resin s MB S Resin s Methy l Methacrylat e acrylonitrile

butadiene-styren e (MABS ) Polyme r «n—1 1 capacit yno t known . bIncrease d capacit ydu e on-lin e b y Source : Referenc e 11 . th e en d o f 1987 . Mod e o f

Operatio n Unknown

Unknown

Unknown Unknown Unknown Batc h Unknown Batc h Unknown 198 6 Desig n

Capacit y (Mg/yr ) (M

M lb/yr )

__ «

24,000 * 5 3

VP. 5 I

Methy l Methacrylate-Butadiene-Styren e Terpolvmer s Methy l methacrylate-butadiene-styren e terpolymer s ar e produce d i n resi n formbyfou r companie s a t fou r locations . Thi s resi n i s use d a s a n impac t modifie r i n rigi d polyviny l chlorid e product s fo r application s i npackaging , building , and construction . Productio n o f MB S terpolymer s i s achieve d usin g a n emulsio n proces s i n whic hmethy l methacrylat e and styren e ar e grafte d ont o a styrene-butadien e rubber . Th e produc t i s a two phas e polymer. " Methy l Methacrvlate-AcrYlonitrile-Butadiene-Styrgn e Polymer s Methy l methacrylate-acrylonitrile-butadiene-styren e polymer s ar e produce d b

yStandar d Oi l Compan yunde r th e trad e nam e Barex® . Th e MAB S copolymer s ar e prepare d b ydissolvin g o r dispersin g polybutadien e rubbe r i n a mixtur e o f methy l methacrylate

acrylonitrile-styren e and butadien e monomer . Th e graf t copolymerizatio n i s carrie d ou t b ya bul k o r a suspensio n process . Th e fina l polyme r i s tw o phase , wit hth e continuou s phas e terpolyme r o f methy l methacrylate , acrylonitrile , and styren e grafte d ont o th e disperse d polybutadien e phase. 1 1 Thes e polymer s ar e use d i n th e plastic s industryi n application s requirin g a tough , transparent , highl yimpact

resistant , an

d thermall yformabl e material . Excep t fo r thei r transparency , th e MAB S polymer s ar e simila r t o th e opaqu e acrylonitrile-butadiene-styren e plastics . Th e primaryfunctio n o f methy l methacrylat e i s t o matc hth e refractiv e indice s o f th e tw o phases , thereb yimpartin g transparency. 1 1

9 3P. 6

REFERENCE S FORSECTION5 1 . Swett , R . M . Polystyrene . Moder n Plastic s Encyclopedia . 63:74-78 . 1986-1987 . 2 . Kirk-Othme r Encyclopedi a o f Chemica l Technology . 3rd Edition . Styren e Plastics . JohnWile yand Sons . Ne wYork , Ne wYork . Vol . 1 , pp . 427-441 , Vol . 21 , pp . .801-811 . 1978 . 3 . Industria l Proces s Profile s fo r Environmenta l Use . Chapte r 1 0 - Th e Plastic s and Resin s Productio n Industry , pp . 74

- 93 , 465-518 , 641-657 . 4 . Click , C . N . and D . K . Webber . Polyme r IndustryRankin g b y VO C Emission s Reductio nTha t Woul d Occu r FromNe wSourc e Performanc e Standards . Prepare d fo r U . S . Environmenta l Protectio n Agency , Researc hTriangl e Park , NorthJ^arolina . pp . 187-198 , 227 , 233-236 . 1979 . 5 . SR I International . 199 0 Directoryo f Chemica l Producer s - U.S.A . Menl o Park , California . 6 . A . T . Kearney . Impac t Analysi s o f th e EPAOffic e o f Drinking Wate r Proposa l t o Regulat e Styrene . Styren e Informatio n Researc hCenter . 1989 . 7 . Chemica l Produc t Synopsis . Polystyrene . Apri l 1988 . 8 . U . S . Environmenta l Protectio nAgency . Polyme r Manufacturin g Industr y- Background Informatio n fo r Propose d Standards . Draf t EIS . EPA-450/3-83-019a . U . S . Environmenta l Protectio n Agency , pp . 3-4 0 t o 3-53 . 1985 . 9 . U . S . Environmenta l Protectio nAgency . Guidelin e Serie s - Contro l o f Volatil e Organi c Compound Emission s from Manufactur e o f High-Densit yPolyethylene , Polypropylene , an d Polystyren e Resins . EPA-450/3-83-008 . U . S . Environmenta l Protectio n Agency , pp . 2-1 8 t o 2-25 . 1983 . 10 . Lette r fro

mJ . S . Matey , Chemica l Manufacturer s Association , t o E . J . Vincent , U . S . Environmenta l Protectio nAgency . Octobe r 19 , 1981 . 11 . Buchanan , S . K . Locatin g and Estimating Ai r Emission s from Source s o f 1,3-Butadiene . EPA-450/2-89-021 . U . S . Environmenta l Protectio nAgency , Researc hTriangl e Park , Nort hCarolina , pp . 44-45 , 71-79 . 1989 . 12 . Chi , C . T . e t al . Sourc e Assessment : Rubbe r Processing , Stat e o f th e Art . EPA-600/2-78-004J . U . S . Environmenta l Protectio n Agency , pp . 12-21 . 1978 .

9 4P. 7

13 . Chemica l an

d Proces s TechnologyEncyclopedia , pp . 387-392 . 1974 . 14 . U . S . Environmenta l Protectio n Agency . Guidelin e Serie s - Contro l o f Volatil e Organi c Compound Emission s from Manufactur e o f Styrene-Butadien e Copolymers . U . S . Environmenta l Protectio nAgency , Researc hTriangl e Park , Nort hCarolina . PreliminaryDraft , pp . 2-12 . 1981 . 15 . Pope , A . A . e t al . Toxi c Ai r Pollutan t Emissio nFactor s - A Compilatio n fo r Selecte d Ai r Toxi c Compound s and Sources . EPA-450/2-88-006 . U . S . Environmenta l Protectio nAgency , Researc hTriangl e Park , Nort hCarolina , p . 4-216 . 1988 . 16 . Rubbe r Product s Styrene-Butadien e Rubbe r Manufacture . Emissio n Tes t Repor t Genera l Tir e and Rubbe r Company , Mogador e Chemica l Plant , Mogadore , Ohio . U . S . Environmenta l Protectio n Ageney , Researc hTriangl e Park , Nort hCarolina . EMB Repor t No . 79-RBM-4 . 17 . Shay , J . J . Styrene-Acrylonitrile . Moder nPlastic s Encyclopedia . 63:88-89 . 18 . Energyand Environmenta l Analysis , Inc . Sourc e Categor y Surve yfo r th e Acrylonitril e Industry- Draf t Report . Prepare d fo r U . S . Environmenta l Protectio nAgency , pp . 3

- 10 , 3-3 0 t o 3-37 . 1981 . 19 . Click , C . N . and D . O . Moore . Emission , Proces s and Contro l TechnologyStud

yo f th e ABS/SAN , Acryli c Fiber , and NB R Industries . Prepare d fo r U . S . Environmenta l Protectio n Agency . Pullma n Kellog . Houston , Texas , pp . 18 , 33 . 1979 . 20 . Chemica l Profile : Styrene . Chemica l Marketin g Reporter , pp . 49 , 50 . Augus t 14 , 1989 . 21 . U . S . Environmenta l Protectio n Agency . Locatin g and Estimatin g Ai r Emission s FromSource s o f Acrylonitrile . EPA-450/4-84-007a . U . S . Environmenta l Protectio nAgency , Researc hTriangl e Park , Nort hCarolina , pp . 34-45 . 1984 . 22 . Hensley , D.S . and CA . Johnson . AB S and Relate d Multipolymers . Moder n Plastic s Encyclopedia , pp . 6-7 . 1985-1986 . 23 . Memorandu

m from R . Bur t and R . Howie , Radia nCorporation , t o L.B . Evans , EPA/Chemical s and Petroleu mBranch , Januar y29 , 1986 . Estimate s o f Acrylonitrile , Butadiene , and Othe r VO C Emission s an

d Control s fo r AB S an d NB RFacilities .

9 5P. 8

24 . Lantz , J . M . AB S and Relate d Multipolymers . Moder n Plastic s Encyclopedia , pp . 6,8 . 1986-1987 . 25 . Considine , D . M . ed . Acrylonitrile-Butadiene-Styren e Resins . Chemica l and Proces s TechnologyEncyclopedia . McGraw-Hil l Publishin g Co. , Lo s Angeles , California , pp . 32-34 . 1974 . 26 . Rolston , J . A' . Fiberglas s Composit e Material s and Fabricatio n Processes . Chemica l Engineering , January28 : 96-110 . 1980 . 27 . U . S . Environmenta l Protectio nAgency . Compilatio no f Ai r Pollutan t Emissio n Factors . EPA-AP-42 . U . S . Environmenta l Protectio n Agency , Researc hTriangl e Park , Nort hCarolina , pp . 4.12- 1 t o 4.12-3 . Septembe r 1985 . 28 . Lette r fromRandazzo , C. , SP I Composite s Institute . Comment s o n draf t "Locating and Estimatin g Ai r Emission s fromSource s o f Styrene " document . Decembe r 1990 .



### 9 6SECTION6

EMISSION S FROMTH E US E O F STYRENE-CONTAININGMATERIAL S

A s discusse d i n Sectio n 3 , styrene-base d resin s ar e presen t i n manymaterials , includin g packaging , appliances , buildin g materials , furniture , electrica l materials , housewares , rubbe r products , paints , adhesives , and automotiv e and recreationa l equipmen t parts . Section s 4 an d 5 evaluat e th e potentia l fo r styren e emission s fromstyren e productio n and from th e majo r intermediat e styren e processors . Ofte nthes e processor s sel l th e resin s a s pellets , granules , powders , o r liquids. 1 Thes e resin s ma ythe n b e combine d wit hcolorant s and filler s befor e the yar e transferre d t o th e fabricato r fo r manufactur e o f th e fina l product . Alternately , th e resi nma yb e sol d t o a separat e compoundin g facilit yfo r thi s treatment . Th e fabricator s the n extrude , inject , o r spraystyrene-base d resin s t o mak e th e fina l products . T o provid e som e ide a o f th e prevalenc e o f styrene-containin g produc t manufacture , Tabl e 2 0 present s a n estimat e o f th e tota l numbe r o f som e o f th e styreni c resi nfabricator s i nth e Unite d States . I n additio n t o th e resi nproducer s liste d i n Section s 4 and 5 , an additiona l 20 0 distributor s and compounder s sel l styreni c resin s t o fabricator s i n th e Unite d States. 1 Th e productio n proces s description s an d emission s dat a presente d i n thi s sectio n cove r som e o f th e mos t commo nprocesse s and products . Becaus e o f styrene' s widesprea d use , al l processe s canno t b e include d here . Furthermore , emission s dat a wer e limited . Individual s ar e encourage d t o examin e th e list s o f fina l product s i n Sectio n3 t o identif yspecifi c facilitie s t o contac t fo r emission s information . Thi s sectio n als o describe s th e result s o f industria l hygien e measurement s o f th e releas e o f styren e fromth e



### 9 7P.1 0

TABL E 20 . PREVALENC E O F STYRENI C RESI NFABRICATOR S

Typ e o f Facilit y UP Rfabricators , culture d marbl e UP Rfabricators , marin e UP Rcompounder s (bul k and shee t molding ) UP Rfabricators , -tubs , showers , spas , an d ho t tub s Tir e and inne r tub e manufacturer s (SB Ruse ) Crysta l and/o r IP S Polystyren e foa

mproducer s Numbe r 1,60 0

. 97 7 

### 2 8 

### 19 7 5 6 2 9 

### 23 7 Source : Reference s 1 and 2 .



### 9 8P.1 1

thermodegradatio n o f styrene-containin g thermoplastics . I n addition , thre e categorie s o f styren e emissio nsource s ar e described . Th e firs t i s styren e emission s froma n acrylonitrile-butadiene-styren e (ABS ) compoundin g facilit ytha t receive s AB S granule s and add s colorants . Th e second categoryi s styren e emission s fromunsaturate d polyeste r resin s (UPR ) us e i n differen t moldin g processes . Finally , th e proces s description s fo r th e manufactur e o f polystyren e foamproduct s fo r drinkin g cups , loos e fill , and othe r product s ar e provided ; n o emission s dat a ar e availabl e fo r thi s category . THERMODEGRADATIONO F STYRENE-CONTAININGMATERIAL S On e les s obviou s sourc e o f styren e emission s i s th e thermodegradatio n o f styrene-containin g material s t o formth e fina l product . Becaus e th e processin g o f thes e material s typicall yinvolve s hig htemperatures , varyin g amount s o f occlude d styren e monome r ma yb e released . Styrene-containin g thermoplastic s ar e extrude d o r molde d (b yinjection , compression , o r blowing ) a t temperature s tha t rang e from15 0 t p 320°C . Th e followin g informatio n o n th e releas e o f styren e monome r during th e processin g o f PS , impac t (IPS) , ABS , an d SA Ni s base d o n industria l hygien e investigation s conducte d i nSwede nan d Finland. 3 ' 4

I n general , th e thermostabilit yo f thes e material s i s dependen t o n thei r molecula r weight , mod e o f polymerization , and composition. 4 Tabl e 2 1 show s th e rang e o f styren e monome r release d during th e thermooxidativ e degradatio n o f styrene containin g materials . Th e temperature s use d and th e oxyge n conten t during combustio n wer e intende d t o represen t thos e encountere d i n industria l proces s situations . Fo r PS , typica l processin g temperature s ar e 15 0 t o 280° C fo r extrusio nand injectio n moldin g and 19 0 t o 235° c fo r blo wmolding. 4



### 9 9TABL E 21 . STYRENE EMITTE D FRO MTHERMOOXIDATIVE DEGRADATIO N (Mg/g , lb/ton) " Temperatur e Impac t Acrylonitrile

- Styrene

- (°C ) Polystyren e Polystyren e Butadiene-Styren e Acrylonitril e 19 7 — b—7800 , 15. 6 (68) c 20 0 Trac e 20 8 —— 2300 , 4. 6 (32 ) 21 8 ———2700 , 5. 4 (3.2 ) 22 4 —310 , 0.6 2 (3.4 ) 24 0 520 , 1.0 4 (8.0 ) 25 0 740 , 1.4 8 (7.0 ) 280 , 0.5 6 (3.8 ) o "Uncontrolle d emissions , tn—I I No t measured . c Styren e yiel d i s give n i nparenthesi s a s th e percentag e o f tota l los s i nweight . Source : Reference s 3 and 4 .P.1 3

Polystyren e i s th e mos t thermostabl e o f th e styrene-containin g material s studied , and i s considere d stabl e durin g commercia l moldin g an

d extrudin g a t temperature s belo w275°C. 4 ACRYLONITRILE-BUTADIENE-STYRENE COMPOUNDING Th e followin g materia l wa s provide d bya Stat e ai r pollutio n contro l offic e followin g sourc e testin g o f a nAB S compoundin g facility. 9 Uncontrolle d styren e emission s fo r thi s facilit yar e presente d unde r tw o differen t scenario s and th e facility' s origina l contro l system , a wate r spra yscrubber , wa s evaluate d fo r it s effectivenes s i n reducing styren e emissions . Th e facilit yoperator s and Stat e representative s the ninstalle d and teste d a n interi mcontro l measur e o f tw o packe d column s i n serie s i n a n effor t t o temporaril yreduc e styren e emission s whil e designin g a permanen t contro l system . Onc e installed , th e permanen t contro l syste m wa s found t o b e 99. 5 percen t effectiv e i n reducing tota l styren e emissions . Th e applicabilit yo f thi s informatio n t o othe r facilitie s i s no t known , no r i s ther e an y informatio n o n th e numbe r o r locatio no f simila r facilities . Proces s Descriptio n Th e AB S compoundin g facilit yreceive s granulate d AB S resin , mixe s th e resi n wit hdye s an d additives , and extrude s th e fina l produc t (Step 1 ) int o pellet s fo r shipmen t (Figur e 19) . Th e splan t operate s si xextruders ; al l o f th e extrude r vacuu mvent s ar e pumpe d t o on e wate r ring vacuu mpum p (Step 2) . Al l di e vent s ar e als o pumpe d t o a commo n ven t and a commo n blower . Th e gaseou s component s ar e pulle d int o th e ven t system , whil e th e wate r i s discharge d t o th e oil-wate r separatio n sum p (Step 3) . Th e discharg e fromth e oil-wate r separatio nsum p (Step 4 ) i s the n sen t througha baske t straine r an d baffle d t o separat e th e oi l fromth e water . Th e oi l i s hand skimme d and th e wate r i s sen t t o a rotating biologica l contacto r (RBC ) fo r biologica l treatment .



### 10 1

## ®

Vacuu m Pum p Wate rSpra y Scrubber

SprayWate r Drai n Air-Wate r Separato r

AB S Pellets i , , 

## © Mai n Exhaust Stac k

Secondary source s Storag e an d loadin g losse s Oil-Wate r Separatio n Sum p

T o Biologica l Treatmen t

Denotes potentia l locatio n o femissio n source 

### Figur

e 19 . Origina l Vacuu m an d VentSyste m a ta n AB S Compoundin g Facilit yP.1 5

Th e RB C sum

p and th e outle t from th e RB C ar e als o pipe d int o th e di e ven t system . Emissio n Measurement s Th e emission s fromth e di e and vacuum pum p stream s wer e teste d unde r a variet yo f contro l situation s and ar e discusse d below . I n addition,-styren e emission s wer e monitore d t o compar e th e emission s whe n th e oil-wate r separatio n tank wa s enclose d and whe n i t wa s open . Th e emission s wer e measure d b yga s chromatograp h(GC ) analyse s and delt a nonaqueou s volatil e (NAV ) mas s balance . Th e extrude r vacuumpum p and di e ven t emission s wer e teste d unde r fou r scenarios : uncontrolle d wit hth e oil-wate r separatio n tank ope n and enclosed , an d controlle d wit ha wate r spray scrubbe r wit hth e oil-wate r separatio ntan k ope nan d enclosed . Th e vacuu

m pum p discharg e fromth e separato r wa s als o disconnecte d from

th e mai n stac k t o measur e it s emission s separately . Ga s chromatograp hstyren e measurement s wer e als o take n around th e oil-wate r separatio nsump . O f th e tota l emissions , th e majorit ywer e fro m th e vacuum pum p discharge , wit hth e remainde r comin g from th e di e vent . Stac k emission s increase d 2 0 percen t whe n th e oil-wate r separatio n sum

p wa s enclose d du e t o th e reductio n i nfugitiv e losses . Th e result s showe d tha t th e wate r sprayscrubbe r wa s onl y2 5 percen t efficien t i n reducin g styren e emissions , and i n on e measuremen t th e controlle d emission s wer e actuall yhighe r tha n uncontrolle d emissions . Attempt s t o reduc e vacuu mpum p emission s wit ha wate r sprayi n th e outle t lin e wer e onl y1 2 percen t effectiv e i n overal l emissio n reduction . Emissio n estimate s derive d fromGC analysi s wer e the n compare d wit hestimate s fromNAV . The * NA V i s a mas s balanc e estimat e determine d b ymonitoring resi nconten t o f th e AB S resin , pellet s produced , ven t oi l sludge , and vacuumpum p discharg e 10 3P.1 6

water . I n general , GC and NA V wer e found t o agre e withi n 2 1 percent . Becaus e th e wate r sprayscrubbe r doe s no t adequatel ycontro l styren e emissions , design o f a bette r systemwa s proposed . I n th e interim , tw o packe d column s i nserie s vente d t o a temporar y carbo n adsorptio n systemwer e installed . Th e water/ga s mixtur e discharge d from

th e vacuu

mpum p wa s firs t sen t t o a n air-wate r separator , and th e ai r leaving th e separato r wa s scrubbe d i ntw o columns . Wate r wa s fed t o th e column s from a recirculatio n tank . Atota l o f 4 0 gallon s pe r minut e (gpm ) wer e circulate d throug h eac hcolumn . Abou t 6 gpmwa s draine d fromth e recirculatio ntan k fo r treatmen t i n th e RBC . Th e ai r leaving th e second columnwa s heate d t o rais e th e relativ e humidit yabov e 5 0 percen t and sen t t o a Calgo n uni t fo r carbo n adsorptio no f th e styrene . Afte r passin g throug hth e carbo n adsorptio n bed , th e vacuum pum p ai r streamcombine d wit hth e di e ven t stream . Thi s ai r streamthe n passe d throughth e wate r sprayscrubbe r system . Tes t result s showe d a tota l styren e emissio n reductio nfromth e vacuumpum p exhaus t and di e ven t o f 96. 4 percent . Tabl e 2 2 present s th e emissio n factor s develope d fromthes e data . Permanen t VO C control s wer e installe d o nthi s AB S compoundin g facilit ya t a late r dat e (Figur e 20) . Th e ai r from th e air-wate r separato r (abou t 20 0 standar d cubi c fee t pe r minut e (scfm) ) i s scrubbe d i ntw o columns . Th e outle t o f th e second scrubbe r passe s througha hea t exchanger . Th e ai r the npasse s throug htw o smal l carbo n bed s (2,00 0 pound s each ) and th e outle t o f th e second be d i s joine d wit hth e outle t o f th e di e ven t systemblower . Thi s ai r the npasse s throughtw o larg e carbo n bed s (4,00 0 lb s each) . Follow-up sourc e testin g indicate d tha t emission s wer e reduce d bymor e tha n99. 5 percen t fo r tota l reactiv e organi c compounds . Tabl e 2 3 present s th e emission s informatio n fo r styren e a t th e outle t o f th e firs t larg e carbo n be d ( a wors t cas e scenari o i f operatin g o n onl yon e bed) , and a t th e outle t o f th e second larg e carbo n bed . 

### 10 4TABL E 22 . SUMMAR YOF SOURC E TESTIN GDAT A FO RA N AB S COMPOUNDIN

GFACILITYUNCONTROLLEDANDWIT HTEMPORARYCONTROL S

Emissio n sourc e Extrude r vacuun punpanddi e vent Sam e a s above Sam e a s above
Sam e a s above Extrude r vacuu

m pui p Sam e a s above Di e ven t Same a s above Extrude r vacuun punpanddi e ven t Same a s above Sam e a s above Sam e a s above Extrude r vacuun pum p Contro l devic e

Mate r scrubbe r

non e Mate r scrubbe r

non e Mate r scrubbe r

non e Mate r scrubbe r non e Mate r scrubbe r

non e wate r scrubbe r

non e scrubber/carbo n adsorption Dat a basi s

(NA V o r GO * G C

G C G C G C G C G C G C G C NA V NA V NA V NA V G C Emissio nfacto r

(lb s sty/10 3 lbs produc t or K gsty/Mgproduct )

1.19 6

1.67 6 1.03 3 1.36 6 1.12 9 1.11 3 0.01 3 0.01 3 1.42 0 1.79 0 1.17 5 1.30 7 0.00 6 Conrnent s

o U l Nonna iproces s operation , oil-Hj O separato rtan k enclosed , 6line s running(max. productionrate ) Sam ea s abov e Nonna i operation , oil-H-, 0 separato rtan kopen , highe r fugitives , les s proces s emission s Same a s above Vacuu npum

pdischarg e measure dseparatel y fro m di e ven t Same a s above Same a s above Same a s abov e Nonna i operation , 6 line s running , oil-Hj Oseparato r tankenclose d Same a s above Nonna i operatio nbu t discharge s measure dseparately , emissio nfacto rrepresent s combine demission s Same a s above Measure da tcarbonadsorptio noutlet , oll-H-,0pun p separato renclose d (continued )TABL E 22 . (Continued )

Emissio n sourc e

Extrude r vacuu n punpanddi e ven t Extrude r vacuu

m punp Contro l devic e

scrubber/carbon adsorptio n

non e Dat a basi s

(NA V o r GC) *

G C

G C Emissionfacto r

(lb s sty/10 3 lb s produc t o rK gsty/Mgproduct ) Comment s

Same a s above scrubbe r G C 0.04 2

1.29 1 0.85 9 Mai nplan t exhaus t afte rcontrol , oil-Hj Oseparato r enclosed , vacuunpump s scrubbe randadsorbe r controlled , di e vent s scrubbe rcontrolle d Uncontrolle dvacuu npun pemission s measure dprio r t oscrubbe r Emission s measure dafte rscrubber s an dprio rt o carbo nadsorptio n

o ON 'NA

V « nonaqueou s volatil e (mas s balanc e o f residua l hydrocarbon s i nthe resin , pellets , ven t oi l andHastewater) . GC= Ga s ChromatographAnalysi s

T J o oVentHood s Di e Vents BerlngerOve n RB C Sum p (A

) RBC(B ) 

# •~-g > 

# ~ - Blowe r# 1

Blowe r# 2 

# nl 400 0 b .Carbo n Adaocptlo n Peek

O Extruder Vacuu m Part s - lAlr/H^ D

Vacuu m Pumps •HXJ—QHXJ- 1

Alr/Hp Separato r Scrubbe r# 2 Scrubbe r# 1

•Hg Q Make-u p Stac k 

# i r j 4000bCaibo n Adsorptio n Pac k *XJ Al r Heat Exchange r Ai r H 2 0 Ai r

Blowdown

i p I L

_H r \ » i Ven t Sump 20001 b

Carbo n Adsorbtlo n Pac k H^ O Make-u p 20001 b Carbon Adsorbtlo n Pac k _Al r£

_

RB C Sum p RB C Cit ySewe r 

### fi Figur e 20 . PermanentVO C Control s a ta n AB S Compoundin g Facilit y 

## P Ic oP.2 0

TABL E 23 . SUMMARYO F AB S COMPOUNDINGFACILIT YSOURC E TES T DAT AAFTE RINSTALLATIONO F PERMANENT CONTROLS *

Emissio n Sourc e Outle t o f firs t larg e carbo n be d Outle t o f firs t larg e carbo n be d Vacuumpum

p outle t Vacuumpum

p outle t Outle t o f second smal l carbo n be d Outle t o f firs t smal l carbo n be d Outle t o f second Styren e Emissio n Factor 4 " 0.001 2

0.001 7 1.515 7 1.650 7 0.001 2

0.001 7

0.001 7 Comment s

smal l carbo n be d Si xline s running (max . productio n rate ) Fiv e line s running Si xline s running Fiv e line s running Si xline s running afte r chang e o f smal l carbo n be d Fiv e line s running afte r chang e o f smal l carbo n be d Fiv e line s running afte r chang e o f smal l carbo n be d "Measure d b

yga s chromatograph . b lbs/10 3 l bproduc t o r kg/M g product .



### 10 8P.2 1

UNSATURATE D POLYESTE RRESI NUS E Styrene-containin g UP Ri s use d i nth e manufactur e o f boats , vehicl e components , bowlin g balls , bathroo m fixtures , gasolin e storag e tank s an

d othe r products . Unsaturate d polyeste r resin s ca n b e use d i nreinforce d o r non-reinforce d applications . Eight ypercen t o f UP Ri s reinforced , usuall ywit hglas s fibers , and extende d wit hvariou s inorgani c fille r material s suc ha s calciu m carbonate , talc , mic a o r smal l glas s spheres.*' 7 Thes e composit e material s ar e ofte n referre d t o a s fiberglas s reinforce d plasti c (FRP) , o r simpl y fiberglass. * Th e Societ yo f th e Plastic s Industrydesignate s thes e material s a s "reinforce d plastic/composites " (RP/C) . Also , advance d reinforce d plasti c product s ar e no wformulate d wit h fiber s othe r tha n glass , suc ha s carbon , arami d and aramid/carbo n hybrids. 7 Reinforce d UP Ri s use d t o mak e boat s an d marin e accessories , tuband showe r stalls , transportatio n component s an d recreationa l vehicl e components. * Nonreinforce d UP Ri s use d i n castin g processe s t o mak e simulate d marbl e products , cas t furnitur e parts , buttons , and bowlin g balls . Moldin g processe s ar e eithe r close d o r open . Close d moldin g technique s ar e compression , injection , pultrusion , continuou s lamination , marbl e casting , ba g molding , and resi n transfer . Ope n moldin g processe s ar e han d layup , filamen t winding , an( i spraylayup . Selectio n o f close d o r ope n moldin g depend s o nth e •siz e an

d volume o f th e produc t t o b e manufactured . Ope nmoldin g i s use d fo r larg e part s suc ha s boat s and recreationa l vehicl e structures . Ope n moldin g processe s o f spraylayu p an d hand layu

p

*A s use d i n thi s report , "fiberglass " mean s glas s fiber s o r fiberglas s reinforce d plastic . Th e termdoe s no t necessaril y mea n "FiberglasTM , trademar k o f Owens/Cornin g Fibergla s Corporation , Toledo , Ohio . 10 9P.2 2

offe r advantage s fo r firm s tha t produc e a limite d numbe r o f unit s fo r eac hmold , requir e rapi d startup , and operat e wit hrestricte d capita l fo r tooling . Becaus e o f limite d productio n and/o r uniqu e designs , man

yfabricator s wil l continu e t o rel yo n ope nmol d fabrication . I n descendin g orde r o f resi n use , th e UP Rmoldin g processe s are: 7 Spraylayup (sprayup) ;

Hand layup ; .Continuou s lamination ; Pres s molding ; Marbl e casting ; ~ """ Pultrusion ; Filamen t winding ; Resi n transfe r molding ; an d Ba g molding . Proces s description s fo r thes e moldin g processe s ar e give nbelow . Ope n Molding Mos t ope n mol d fabricator s us e simila r processe s t o produc e product s wit hvaryin g composition , sizes , and shapes . Fo r product s wit ha smooth , durabl e surface , a smoot han d highl y polishe d mol d i s required . Fo r man yproducts , a catalyze d ge l coa t i s applie d a s th e initia l step . Th e resin s ar e generall y eithe r han

d rolle d o r spraye d int o th e fiberglas s reinforcement . /"• ' Som e hand rolling i s essentia l eve n whe n th e resi n i s sprayed , fo r removing void s and ensuring prope r compactio no f resi nand reinforcing material . ; . •-: ' '.-Mostope n moldfabricatio n 1 facilities.consis t ;.o f on e o r mor e ope n productio n areas . I nthes e ope n areas , a larg e numbe r o f exhaus t fan outlet s ar e provided . Emission s ca nb e reduce d by usin g airles s sprayguns , spraybooth s fo r ge l coatin g and resi n application , isolate d wor k bayoperations , and ai r filtration . 

### 11 0P.2 3

SprayLayup — I n UP Rspraylayup , th e mol d define s th e shap e o f th e oute r surface , and th e mol d itsel f i s usuall ymad e o f reinforce d plastic . Th e mol d i s firs t coate d wit ha wa xt o ensur e remova l afte r curing . Alaye r o f ge l coa t i s the nspraye d o nt o th e mol d t o for mth e outermos t surfac e o f th e products . Ge l coat s ar e highl ypigmente d unsaturate d polyeste r resin s tha t provid e a smooth , colore d surfac e tha t give s th e appearanc e o f a painte d part. ' Th e ge l coa t i s allowe d t o cur e fo r severa l hour s bu t remain s tackys o subsequen t resi n layer s adher e better . Th e polyeste r resi n i s applie d wit ha spraygu n tha t ha s a glas s choppe r attachment . Thi s allow s simultaneou s spraying o f resi n an d choppe d glas s ont o th e mold . Th e spraygunha s separat e resi n an

d catalys t stream s whic hmi xa s the yexi t th e gun . Ai r spraygun s requir e a larg e volum e o f ai r flo wa t highpressures . Thi s provide s goo d contro l ove r spraypatterns ; however , thi s typ e o f spraying contribute s t o excessiv e fogging , overspray , and bounc e back , resultin g i n increase d emission s and materia l loss . T o reduc e styren e emissions , air-assiste d airles s spraygun s ca n b e use d t o appl yge l coat s an d resins . Becaus e highpressur e i s no t neede d a t th e nozzle , air-assiste d airles s spraying result s i n lowe r emission s and les s materia l loss . Unsaturate d polyeste r resin s designe d fo r us e i n spraylayup-ar e promote d fo r cur e a t roomtemperatur e and usuall yar e catalyze d wit ha liqui d peroxid e suc ha s methy l ethy l keton e peroxid e (MEKP). 9

Hand Layup — Hand layup involve s th e sam e initia l step s (u p through applicatio n o f th e ge l coat ) a s use d i n spraylayup . Followin g ge l coa t application , alternat e layer s o f catalyze d polyeste r resi n an

d reinforcemen t materia l ar e applied . Th e rati o o f resi n t o glas s i s usuall y6 0 t o 4 0 b yweight , bu t varie s b yproduct . Eac hreinforcemen t laye r i s "wette d out " wit hresin , an d the n rolle d ou t t o remov e ai r pockets . Th e proces s continue s unti l


### 11 1P.2 4

th e desire d thicknes s i s achieved . Han d layup i s als o a roo m temperatur e curin g process . Filamen t Winding — Filamen t winding , show ni n Figur e 21 , i s th e proces s o f laying a band o f resi nimpregnate d fiber s ont o a rotatin g mandre l surfac e i n a precis e geometri c pattern , and curin g the mt o form th e product . Thi s i s a n efficien t metho d o f producin g cylindrica l part s wit hoptimu mstrengt hcharacteristic s suite d t o th e specifi c desig n an d application . Glas s fibe r i s mos t ofte n use d fo r th e filament , bu t aramid , graphite , and sometime s boro n and variou s meta l wire s mayb e used . Th e filamen t can~b e wette d durin g fabrication , o r previousl yimpregnate d filamen t ("prepreg" ) ca n b e used . Th e thre e mos t commo nwindin g pattern s ar e circumferential , helical , an d pola r winding . Th e variou s windin g pattern s ca n b e use d alon e o r i n combinatio n t o achiev e th e desire d strengt han d shap e characteristics . Mandrel s ar e mad e o f a wid e variet yo f material s and , i n som e applications , remai n insid e th e finishe d produc t a s a line r o r core . Exampl e product s ar e storag e tanks , fuselages , wind turbin e and helicopte r blades , and tubing an d pipe. 7 Close d Moldin g Close d moldin g system s reduc e styren e emission s b y eliminating th e requiremen t fo r atomizatio n o f th e resin . Th e mos t commo n close d moldin g processe s ar e pres s molding , marbl e casting , pultrusion , continuou s lamination , resi ntransfe r molding , and ba g molding . O f these , th e tw o larges t categorie s ar e pres s moldin g and marbl e casting .



### 11 2w

PolarWindin g ( J

Figure 21 . Typica l Filamen tWindin g Proces sPres s Molding — Pres s moldin g include s compression , injectio nand transfe r molding , an d require s a larg e hydrauli c pres s typicall yrangin g from45 4 t o 453 6 M g (50 0 t o 500 0 tons ) i ncapacity . Pres s moldin g use s eithe r bul k moldin g o r shee t moldin g compound s o f resi n and reinforcin g materials. 8 Bul k moldin g compound s ar e produce d i nrop e o r soli d bul k form , and isheet moldin g compound s ar e produce d i n shee t form . Generall yth e UP Rcompounder s hav e indoo r UP Rtank s containin g les s tha n 37,85 3 liter s (10,00 0 gallons ) each . Th e UP Ri s pumpe d fromth e storag e tank s t o a mixin g tan k wher e filler s ^primaril y calcium carbonate , clayo r alumina ) and catalyst s ar e added . T o mak e shee t moldin g compounds , th e resultin g past e i s reinforce d wit hglas s fiber s and forme d int o sheet s o na continuou s basis . T o mak e bul k moldin g compounds , th e past e i s place d i na mixe r wit hglas s fibers . Afte r compounding , th e produc t i s extrude d int o rop e formo r package d i n bul k form . Ai r emission s aris e fromstorag e tanks , mixin g tanks , and mixin g rooms . Compressio n moldin g use s shee t moldin g compound wher e th e shee t i s compresse d betwee n heate d mold s and cured . Injectio n and transfe r moldin g us e bul k moldin g compound . Th e moldin g compound i s force d througha smal l openin g int o a close d heate d mol d and cured. 8 Continuou s Lamination — Garag e doors , truc k be d liners , pati o covers , skylights , an d sola r collector s ar e som e o f th e product s mad e wit hunsaturate d polyeste r resin s usin g th e continuou s laminatio nprocess . A s shown i n Figur e 22 , th e polyeste r resi ni s firs t applie d t o a fil mo n an impregnatio n table

- o n a conveyo r belt . Th e fil m form s th e bottomsurfac e o f th e product . Thi s fil m ca nb e mad e
11 4Resi n Meterin g Devic e

Resi n Mix u i Jk^PlckerRol l To ^ m

Heate d Wetou t Tabl e Botto m Fil m Squeez eRoll s Cur eAre a Cros s Cu tSawo rShea r Ri m Rewin d Edg eTri m 

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Stackin g Devic e

Figure 22 . Typica l Continuou s Laminatio n Productio n Proces sP.2 8

o f polyester , cellophane , o r nylon . Th e resi nusuall ycontain s additive s suc ha s calciu mcarbonat e o r aluminu mtrihydrat e t o increas e weathe r and flame resistance . Choppe d glas s i s the n adde d t o th e we t coa t o f resin , and a to p laye r o f fil mi s adde d an d th e layer s ar e pulle d throughroller s t o remov e ai r bubbles . Th e conveyo r bel t the ncarrie s th e laminat e t o a curin g ove n (200°C) . Afte r exiting th e ove nth e film s ar e remove d and th e laminat e i s trimme d t o th e desire d size. 7 Impregnatio nensure s a hig hdegre e o f contro l o f fiber/resi nrati o and catalyst/resi n ratio . Styren e emission s ar e reduce d a s compare d t o ai r sprayers . Syntheti c Marbl e Casting — Th e polyeste r resi n use d i n syntheti c marbl e castin g usuall y ha s highe r viscosit yand lowe r monome r level s tha nth e resin s use d fo r laminating and ge l coats . Filler s and colorant s ar e mixe d wit hth e resi n i nlarg e vats . T o achiev e th e marble d effect , th e colorant s ar e ofte nhand stirred . Th e mixe d resi ni s the n hand poure d int o partiall yclose d molds . Th e resi ni s cure d a t roomtemperatur e and , afte r curing , th e mol d i s removed . Ge l coat s mayals o b e used , i nwhic hcase , the yar e applie d t o th e mol d surfac e befor e pourin g i nth e resin . Source s o f emission s includ e equipmen t leaks , UP Rstorag e tanks , proces s operations , and transfe r an

d handling operations . Th e majo r source s o f proces s operatio n emission s ar e th e ge l coa t are a and castin g areas , wher e UP Ri s mixe d and poure d int o molds . r Pultrusion — Pultrusion , whic hca n b e though t o f a s extrusio nbypulling , i s use d t o produc e continuou s cross-sectiona l lineal s simila r t o thos e mad e b

yextruding metal s suc ha s aluminum . Reinforcin g fiber s ar e pulle d throug ha liqui d resi n mi xbat hand int o a long machine d stee l die , wher e hea t initiate s a n exothermi c reactio n t o polymeriz e th e thermosettin g resi n matrix . Th e composit e emerge s fro

mthe di e a s a hot , constan t cross-sectiona l profil e 11 6P.2 9

tha t cool s sufficientl yt o b e fe d int o a clamping and pullin g mechanism . Th e produc t ca nthe nb e cu t t o desire d lengths. 7 Th e fina l pultrude d produc t i s typicall ya t leas t 7 0 percen t reinforcemen t b

yweight . Thes e product s ar e use d i n th e electrica l and buildin g industries . Resi n Transfe r Molding — Resi n transfe r moldin g i s a lo wpressur e close d moldin g proces s whic hi s normall ycarrie d ou t a t roomtemperature . I n th e process , continuou s o r choppe d strand glas s fibe r mat s ar e place d i n a mold , wit hcatalyze d resi ninjecte d afte r th e mol d i s closed . Becaus e n o resi n surface s ar e expose d t o ai r durin g curing , styren e emission s fro mthi s moldin g proces s ar e greatl y reduce d a s mor e styren e i s retaine d i nth e mixtur e and adde d t o th e polyme r a s i t cures , instea d o f volatilizing ou t o f th e mixture . Ge l coats , whic har e ofte nuse d wit hresi ntransfe r molding , ar e applie d t o th e mold s (whic hmayb e reinforce d plastic) . Afte r th e ge l coa t cures , glas s reinforcemen t i s place d i n th e mol d and resi n i s injected . Thi s moldin g proces s i s bes t use d fo r intermediat e volum e productio no f smal l t o mid

size d component s suc ha s restauran t seats , hatches , doors , automotiv e parts , tubs , and showe r units. 8

Ba g Molding — Ba g moldin g i s bes t use d t o produc e an intermediat e volum e o f smal l t o mid-siz e component s suc ha s seats , boa t hatches , boa t dec k structures , and othe r item s wit hshallo wdraf t molds . Ba g moldin g i s conducte d i n seale d mold s a t roomtemperature . Th e proces s i s initiate d wit hge l coa t applie d t o th e surfac e o f th e mold . Glas s reinforcing fiber s and othe r material s ar e carefull y cu t t o fi t th e mol d and place d ove r it . Catalyze d resi ni s sprayed , pumpe d o r poure d ove r th e layup . Onc e th e layu p material s ar e i n place , th e expose d are a i s covere d wit hspecia l layer s o f plasti c whic har e seale d t o th e edge s o f th e mold . Styren e emission s occu r primaril yfromge l coa t layup , UP R 11 7storage , and handlin g operations . Th e ba g moldin g proces s use s a

ba g o r flexibl e membran e t o appl ypressur e durin g molding ; usuall yi n conjunctio nwit ha nautoclave. 1 0 Areinforce d laminat e i s laye d u p byhand o r spraye d and pressur e i s applie d b ydrawin g a vacuumunde r a cellophane , vinyl , o r nylo nba g covering it . Thi s assembl yi s the n heate d unde r pressur e i na n autoclave . Th e us e o f ba g moldin g allow s th e fina l produc t t o hav e a highe r fiberglas s t o resi n ratio. ' Spas/Tubs/Showers — Ope n mol d processe s (spra ylayup ) ar e use d t o fabricat e spas , tubs , and showers . Th e proces s consist s o f ge l coa t sprayup an

d laminatin g operations . Th e polyeste r resi ni s hand rolle d t o buil d successiv e layer s o f reinforce d plastic . Th e produc t i s usuall ycure d a t roomtemperature . Significan t source s o f emission s ar e fromUP Rstorage , transfe r operations , and ope n mol d operations . Fiberglas s Boa t Production — Th e fiberglas s boa t industryi s a larg e consume r o f UPR , wit hfacilitie s scattere d throughou t th e Unite d States . Th e productio n proces s i s discusse d separatel yher e becaus e n o on e specifi c proces s i s used. 9 Currently , ther e ar e ove r 90 0 fiberglas s boa t plant s i nth e Unite d States . Th e distributio n o f larg e fiberglas s boa t manufacturing facilitie s i n 198 7 b ynumbe r i neac hStat e i s shown i n Tabl e 24 . Onl y1 6 State s d o no t hav e an yfiberglas s boa t manufacturing establishments. 1 1 Furthermore , 1 0 State s hav e mor e tha n 1 0 boa t manufacturin g facilitie s and represen t 6 5 percen t o f th e facilities : California , Florida , Illinois , Indiana , Michigan , Nort hCarolina , Sout hCarolina , Tennessee , Texas , and



### 11 8P.3 1

TABL E 24 . GEOGRAPHI C DISTRIBUTIO N O F TH E FIBERGLAS S BOA T INDUSTRYB YNUMBE RO F FACILITIE S Florid a Tennesse e Californi a Texa s Michiga n South-Carolin a Indian a Illinoi s Washingto n Nort hCarolin a Arkansa s Massachusett s Missour i Louisian a Georgi a Marylan d Minnesot a Rhod e Island Main e Wisconsi n Ne w Jerse y Ohi o Alabama Arizon a Kansa s Oklahoma Orego n Connecticu t Kentucky Mississipp i New Yor k Pennsylvani a Iowa Nebrask a Uta h Virgini a 7 7 4 0 2 3 2 1 1 4 1 4 1 3 1 2 1 1 1 0 9 9 9 9 8 8 8 7 7 6 5 5 4 4 4 4 . 4 3 3 3 3 2 1 1 1 1 TOTAL : 36 3 Source : Referenc e 11 .

11 9P.3 2

Washington . Th e geographi c distributio no f majo r fiberglas s boa t manufacturing facilitie s b yStat e i s presente d i n Figur e 23 . Point s tha t represen t mor e tha n on e establishmen t i na give ncit y ar e assigne d a numerica l value . I ngeneral , th e majo r location s o f fiberglas s boa t manufacturin g facilitie s ar e centere d nea r lakes , rivers , an d coasta l areas. 9 Th e styren e concentratio n o f UP Ruse d i nfiberglas s boa t manufactur e i s usuall y3 5 t o 4 5 percent , and th e styren e conten t o f th e ge l coa t i s typicall y4 5 t o 5 0 percent . Th e mos t commo n fiberglas s boa t productio nproces s i s contac t molding , bot hspra y layu p an d hand layup (Figur e 24). 1 C Concav e femal e mold s ar e preferre d fo r boa t hull s an d deck s a s the yleav e smooth~oute r surface s (mal e mold s leav e smoot hinne r surfaces) . A s discusse d i n th e spraylayup description , a nairles s sprayguni s normall y preferred . Ge l coa t applicatio ntypicall ytake s plac e i na ventilate d sprayare a i nboa t manufacturin g facilities . Hand and spraylayup , a s wel l a s automate d fabricatio n techniques , ca nb e use d i n th e manufactur e o f fiberglas s boats . Ofte nth e firs t laye r i s allowe d t o cur e t o th e touc hbefor e subsequen t layer s ar e applie d t o th e desire d thickness . Automate d layu p o f larg e hul l boat s involve s th e simultaneou s mechanica l applicatio no f resi n an

d reinforcemen t material , and maystil l requir e hand rolling t o remov e ai r bubbles . Spraylayu p i s use d fo r smal l parts , hulls , and decks . Hand roller s ar e als o use d t o remov e ai r bubbles . Smal l part s ar e usuall yproduce d i n a ventilate d boot hi n th e moldin g area . Aseparat e assembl yroomi s use d fo r sanding part s and assemblin g th e entir e craft . Carpe t and othe r fixture s ar e als o installe d i n th e assembl yarea. 9

Ales s commo n moldin g metho d fo r th e fiberglas s boa t manufacturing industr yi s th e resi ntransfe r moldin g proces s typicall yuse d t o manufactur e smal l part s suc ha s boa t seats , hatc hcovers , and bai t boxes. "



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c oP.3 5

Emissio n Measurement s b yMoldin g Proces s Th e U . S . Environmenta l Protectio nAgenc yha s publishe d emissio n factor s fo r fabricatio nprocesse s usin g styren e a s th e monomer. 7 Thes e emissio n factors , shown i nTabl e 25 , ar e presente d a s pound VO C pe r pound monome r used . Styren e i s b yfa r th e mos t commo n monome r used. 7 Tabl e 2 5 include s emissio n factor s fo r vapor-suppresse d (VS ) resins , whic hca n b e use d t o reduc e VO C emission s i n plac e o f nonvapor-suppresse d (NVS ) resins . Discussion s wit hindustr yrepresentative s indicate , however , tha t V S ge l coat s ar e no t used , no r ar e V S resin s use d i n close d moldin g processes. 1 3 Th e Californi a Ai r Resource s Boar d (CARB ) ha s als o develope d emissio n factor s fo r UP Rbymoldin g process."' 1 4 Thes e emissio n factor s ar e show

n i n Tabl e 26 , and ar e base d o n resi n monome r content , layup process , and microenvironmenta l condition s (such a s temperature , indoo r versu s outdoo r processes , and ventilation) . I t shoul d b e note d tha t th e CAR B emissio n factor s ar e give n i n pound s o f monome r emitte d pe r pound o f monome r used . Th e emissio n factor s publishe d b yEPAan

d CAR B ar e simila r fo r manyo f th e processe s showni n Table s 2 5 and 26 . Notabl e exception s ar e th e emissio n factor s fo r han d layup . Th e EPA emissio n factor s ar e muc hlowe r tha nCARB' s emissio nfactors . Sampl e Calculatio n Usin g EPAEmissio nFactors 7 — Afiberglas s boa t buildin g facilit yconsume s a n averag e o f 50 0 l bpe r dayo f styrenercontainin g resin s usin g a combinatio n o f hand layup (65% ) and spraylayup (35% ) techniques . Th e laminating resin s fo r hand and spraylayu p contai n 41. 0 and 42. 5 percent , respectively , o f styrene . Th e resi nuse d fo r hand layu p contain s a vapor-suppressin g agent .



### 12 3P.3 6

TABL E 25 . VO C EMISSIONFACTOR S FORPOLYESTE RRESI NPRODUC T FABRICATIONPROCESS " (Poun d VO C emitted/pound monome r used )

Resi n Proces s NV S V S f c Ge l Coa t NV S VS b Hand Layup SprayLayup . Continuou s Laminatio n Pultrusion * Filamen t Winding " Marbl e Castin g Close d Molding 9 0.05-0.1 0 0.09-0.1 3 0.04-0.0 7 0.04-0.0 7 0.05-0.1 0 0.01-0.0 3 0.01-0.0 3 0.02-0.0 7

0.03-0.0 9 0.01-0.0 5 0.01-0.0 5 0.02-0.0 7 0.01-0.0 2 0.01-0.0 2 0.26-0.3 5

0.26-0.3 5 0.08-0.2 5

0.08-0.2 5

"Range s represen t th e variabilit yo f processe s and sensitivit yo f emissio r t o proces s parameters . Singl e valu e factor s shoul d b e selecte d wit h caution . NV S = nonvapor-suppresse d resin . V S = vapor-suppresse d resin . "Factor s ar e 30-70 % o f thos e fo r nonvapor-suppresse d resins . c Ge l coa t i s no t normall yuse d i n thi s process . "Resi n factor s fo r th e continuou s laminatio nproces s ar e assume d t o apply . •Resi n factor s fo r th e hand layup proces s ar e assume d t o apply . 'Factor s unavailable . However , whe ncas e part s ar e subsequentl yspraye d wit hge l coat , hand an d spraylayup ge l coa t factor s ar e assume d t o appl y "'Resi n factor s fo r marbl e casting , a semiclose d process , ar e assume d t o apply . Source : Referenc e 7 .

|lh: c 12 4P.3 7

TABL E 26 . MONOMER-BASE D EMISSIONFACTOR S FORPOLYESTE R

RESIN/FIBERGLAS S OPERATION S (Poun d monome r emitted/pound monome r used )

Proces s Hand Layup Onl y SprayLayu

p Onl y Hand and Spray Marbl e Castin g Continuou s Laminatio n Pultrusio n Filamen t Windin g Close d Moldin g NV S 0.16-0.3 5 0.09-0.1 3 0.11-0.1 9 0.01-0.0 3 0.06-0.1 3 0.06-0.1 3 0.06-0.1 3 0.01-0.0 3 

### Resi n V S

0.08-0.2 5 0.05-0.0 9 0.06-0.1 3 0.01-0.0 3 0.06-0.1 3 0.06-0.1 3 0.03-0.0 9 0.01-0.0 3 Ge l

NV S 4 7 0.26-0.3 5 0.31-0.3 8 0.26-0.3 5 N A N A 0.26-0.3 5 N A Coa t V S

0.24-0.3 3 0.13-0.2 5 0.16-0.2 7 0.13-0.2 5 N A N A 0.13-0.2 5 N A N A- No t applicable ; ge l coa t normall yno t use d fo r thes e processes . Source : Reference s 1 2 and 14 .

12 5P.3 8

FromTabl e 25 , th e facto r fo r hand layup usin g a vapor suppresse d resi n i s 0.0 2 - 0.0 7 pound s VO C pe r pound monome r used . Th e facto r fo r spraylayu p i s 0.0 9 - 0.1 3 pound s VO C pe r pound monome r use d (NVS) . Assumin g th e midpoint s o f thes e emissio n facto r ranges , an d assumin g tha t al l VO C emission s ar e styrene , tota l styren e emission s are : (50 0 lb ) X[(0.41)(0.04)(0.65 ) + (0.425)(0.11)(0.35) ] =13. 5 lb/day . Th e emissio n facto r range s shownfo r marbl e casting i n bot h table s includ e emission s fo r bot hge l coa t sprayin g and casting . I n general , th e styren e emission s fromsyntheti c marble~casting ar e expecte d t o b e lowe r tha nthos e fromothe r processe s becaus e o f th e close d mol d natur e o f th e process . Emission s varywit h th e amoun t o f tim e th e resi n i s expose d t o air , an d th e majorit y o f emission s wer e du e t o ge l coa t spraying . Fo r continuou s lamination , exposur e o f th e resi n surfac e t o ai r a t th e impregnatio n tabl e i s a sourc e o f styren e emissions . I n addition , th e oven s an d th e fina l sawing operation s releas e som e uncure d resi n t o th e atmosphere . Th e emission s from pultrusio n operation s ar e assume d t o b e th e sam e a s continuou s lamination . Th e prevalenc e o f emissio n contro l us e i nth e UP Rindustry i s no t known . Th e 198 2 Californi a stud yfound tha t V S resin s wer e use d fo r 2 6 percen t o f resi n and ge l coa t application . Vapo r suppressant s ar e typicall yparaffi nwaxe s tha t reduc e styren e emission s bymigratin g t o th e surfac e and reducing volatilizatio n o f styrene . I nlaminating resins , th e vapo r suppressan t conten t ca nrang e from0. 3 t o 0. 6 percen t b yweight . Othe r vapo r suppressant s i n us e ar e thermoplastic s an d fatt yaci d esters . Othe r way s t o reduc e styren e emission s woul d b e t o chang e fromope n t o close d molding , reduc e rollou t times , an d i ngenera l 12 6P.3 9

improv e housekeeping . I n addition , th e amoun t o f polyeste r resi n use d ca n b e reduce d b yredesignin g products , addin g mor e fillers , and improving spraygu nefficiency . Reformulatio no f UP Rcoul d als o b e use d t o reduc e th e monome r conten t i n th e resin . Emissio n Measurement s fo r Fiberglas s Boa t Manufactur e Styren e ca n b e emitte d durin g storag e and transfe r o f th e polyeste r resi n and fromth e laminatio n area . Resi ni s typicall y store d i n outdoo r temperature-controlle d tank s and transferre d t o 55-gallo n drum s fo r sprayapplication . Emission s fro mthes e source s ar e expecte d t o b e smal l compare d t o th e proces s emissions. 9

A s discusse d previously , styren e emission s occu r durin g ge l coa t and resi n applicatio nand fromresi n curing . Ge l coat s ar e typicall yspraye d o n an d th e resin s ar e applie d eithe r b yhand o r spraylayup . Th e emissio n factor s fromhand and spraylayup ar e shown i n Table s 2 5 an d 26 . Severa l factor s influenc e th e styren e proces s emission s durin g fiberglas s boa t manufacture . Thes e includ e resi n temperature , ai r temperature , ai r velocit yi nth e laminatio n area , mol d surfac e area , and spraygu ntransfe r efficienc y (Tabl e 27) . Th e reade r i s encourage d t o contac t th e fiberglas s boa t manufacturing facilit yt o obtai nspecifi c informatio no n th e layu p proces s use d an

d environmenta l condition s i nth e laminatio n are a i n orde r t o bette r estimat e styren e emissions . Contro l o f styren e emissio nfromfiberglas s boa t manufacturin g ca n b e accomplishe d wit hsevera l o f th e option s describe d abov e fo r UP Rus e including: 9

Reductio n o f styren e conten t i nresin ; Improve d transfe r efficienc yo f sprayguns ; 

### 12 7Resi n temperature s

Ai r temperature s Spraygun pressure/equipmen t atomizatio n Ai r velocit yi n laminatio n are a Mol d surfac e are a Resin/ge l coa t styren e conten t Emission s increas e a s temperatur e rise s Emissio nincreas e a s temperatur e rise s Greate r pressur e increase s th e atomizatio n whic hincrease s th e overspray Greate r ai r flo wma yincreas e evaporatio nresultin g i n increase d emission s and decrease d concentratio n Greate r surfac e are a allow s mor e vaporizatio n i nterm s o f tota l mas s Increas e emission s fromincrease d styren e monome r conten t Source : Referenc e 9 .



### 12 8P.4 1

Us e V S resins ; and Us e o f add-o n controls . Th e us e o f lo wstyren e resin s (3 5 percen t styren e versu s 4 3 percent ) ca n potentiall yreduc e tota l styren e emissio nb y1 9 percen t fromresi n applicatio nand curing . Problem s wit h applicatio n mayoccu r a s viscosit yincreases , and curin g problem s mayresul t i n structura l defects . Byimproving th e transfe r efficiencie s o f th e spraygun s use d t o appl yge l coa t and resin , styren e emission s du e t o oversprayca nb e reduce d t o 4 2 percen t fo r ge l coa t and 3 3 percen t fo r resi nspraylayup. 9 Anothe r optio n i s th e us e o f V S resin s whic hmayreduc e styren e emission s by3 0 t o 5 0 percen t durin g curing . However , th e resin s for ma wa xlaye r durin g curin g whic hmus t b e thoroughl yremove d betwee n eac hlaminat e applicatio n t o ensur e interlaminat e bonding . I f maximu mstrengt hi s no t required , reducin g th e curin g tim e betwee n laminat e application s ca npartiall yaddres s th e wa xlaye r buildup problem. 1 2 Becaus e o f th e difficult yi n removin g th e wa x layer , V S resin s ar e onl ysuitabl e fo r selecte d applications . Add-o n control s tha t hav e bee nevaluate d fo r us e b yth e fiberglas s boa t manufacturin g industryinclud e incineration , adsorptio n (mas s transfer ) systems , and absorptio n (we t scrubber ) systems . Non e o f thes e add-o ncontrol s ar e currentl yused , however. 1 3 Problem s (primaril yeconomic ) wit hth e us e o f add-o n control s b

yth e fiberglas s boa t manufacturin g industryar e du e t o th e hig hflo wrate s and lowVO C concentration s i n th e exhaust . POLYSTYRENE FOA

M Polystyren e foam(PSF ) product s consis t o f foa msheet , foa

m board , and expandabl e beads . Thes e product s ar e manufacture d b y eithe r extrusio n o r expandabl e bea d blowing . Th e density , strength , formability , and insulatin g qualitie s o f PS F mak e i t a n idea l materia l fo r packin g "peanuts, " hamburge r boxes , an d ho t o r col d drink cups , and manyothe r products . A198 8 estimat e o f end use s fo r polystyren e resi nindicate s tha t foa mpackagin g account s 12 9P.4 2

fo r 2 6 percent , disposable s accoun t fo r 1 6 percent , consume r and institutiona l product s accoun t fo r 1 6 percent , and expandabl e polystyren e (EPS ) bead s accoun t fo r 1 1 percen t o f tota l Unite d State s polystyren e production . Th e remainde r goe s int o electronics , compounding , furnitur e manufacturing , and construction. 1 5 Mos t extrude d PS F product s ar e manufacture d by polystyren e producers . Blowin g agen t i s incorporate d int o th e polystyren e a s i t i s extruded . Expande d polystyren e products , however , ar e mad e frompolystyren e bead s whic hcontai na n inactiv e blowin g agent . Thes e bead s ar e usuall yproduce d byth e larg e chemica l companies , bu t the yar e expande d and molde d a t differen t facilities . Althoughn o informatio n o n styren e emission s fro mth e manufactur e o f polystyren e foamwa s found i n th e literature , proces s description s and facilit ylocation s ar e provided . Tabl e 2 8 list s th e majo r en d use s o f P S foamboar d and shee t an

d present s tota l Unite d State s consumptio no f P S foam product s i n 1988 . Tabl e 2 9 indicate s th e numbe r o f PS F producer s i n th e Unite d State s b yState . Proces s Descriptio n Polystyren e i s foame d throug hth e us e o f physica l blowin g agent s tha t ar e gase s o r liquid s tha t ar e solubl e i n th e molte n polyme r unde r pressure . Unde r depressurization , th e blowin g agen t volatilizes , causing th e polyme r t o foa mthroug hth e formatio n o f ga s cells . Polystyren e FoamSheet — Th e formatio n o f PS F shee t i s a nextrusio nprocess , commonl y usin g tw o extruder s i n serie s o r on e extrude r wit htw o sections . Th e proces s produce s foa msheet s 1 t o 7 m

mthick , wit hdensitie s o f 3 2 t o 16 0 kg/m 3

. 2 0 Atypica l extrude d PS F foa mshee t manufacturin g proces s flowdiagrami s shown i nFigur e 25 .



### 13 0P.4 3

TABL E 28 . DOMESTI C CONSUMPTIONO F POLYSTYREN E FOA MB YEND USE S 198 8 198 8 End Us e (Mg ) (M Mlb ) Extrude d Foa

m Boar d 66,67 9 14 7 Shee tSingl e Servic e Container s Stoc k Foo d Tray s Eg g Carton s Othe r Foame d Shee t Tota l Foame d Shee t Expandabl e Bead s Building and Construction " Cup s an d Container s Packaging Loos e Fil l

. Othe r EP S Product s Tota l EP S Bea d Product s "Value s includ e constructio nuse s othe r tha n insulation , suc ha s wal l an d ceiling covering s and concret e filler . Source : Referenc e 16 . 156,03 8 86,18 4 36,28 8 15.87 6 361,06 5 77,11 2 75,29 8 48.08 2 27,21 6 35,40 1 253,10 9 34 4

19 0 8 0 _2 5 79 6
17 0 16 6 10 6 6 0 5 6 55 8



### 13 1P.4 4

TABL E 29 . DISTRIBUTIONO F PS F PRODUCER S B YSTAT E Sheet , Film , Board , an d Bloc k Producer s Including FoamBlower s an d Extruder s

Stat e Numbe r o f ' Facilitie s Californi a 2 3 Pennsylvani a 1 9 Michiga n1 4 Mississipp i 1 4 Ne wYor k 1 4 Ohi o 1 4 Illinoi s 1 2 Massachusett s 1 2 Georgi a 1 1 Missour i 9 Ne wJerse y9 Texa s 8 Arkansa s 7 , Connecticu t 7 Florid a 6 Washingto n6 Indiana 5 Wisconsi n5 Colorad o 4 Kentuck y4 Nort hCarolin a 4 Virgini a 4 Maryland 3 Minnesot a 3 Tennesse e 3 Alabama 2 Iowa 2 Nebrask a 2 Rhod e Island 2 Sout hCarolin a 2 Arizon a 1 Hawai i 1 Idah o l Kansa s 1 Ne wHampshir e l Oklahoma 1 TOTAL : 23 7 Source : Reference s 17 , 18 , and 19 ,

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Polystyren e pellet s ar e mixe d wit ha smal l amoun t (0. 2 t o 2 percent ) o f powdere d nucleatin g agen t suc ha s talc , o r a combinatio n o f citri c aci d and bicarbonat e o f sod a (Step l). 2 0 Thi s mixtur e i s fe d int o th e primaryextrude r (Step 2) . Th e extrude r i s heate d t o provid e a nincreasing temperatur e profil e alon g it s length , s o tha t th e polystyren e melts . Th e blowing agen t i s injecte d a s a liquid , unde r highpressure , int o the primar yextrude r wher e i t mixe s wit hth e molte n polystyrene . A scree n i s use d t o remov e impuritie s fromth e molte npolystyren e befor e i t enter s th e secondaryextruder . Th e secondar yextrude r introduce s a coolin g profil e tha t increase s th e mixture' s viscosit yan

d giv e i t enoughstrengt ht o contai nth e blowing agen t a s i t expand s (Step 3) . A s th e viscou s polystyren e mi x leave s th e second extrude r throug ha die , i t foam s and partiall y solidifies . Th e blowin g agen t bubble s attac ht o th e nucleating agen t and a cellula r structur e i s formed . An annula r extrusio n di e i s use d i n extrude d polystyren e shee t production , resultin g i na tubula r form(Step 4) . Foaming initiate s nea r th e di e outle t wher e th e pressur e rapidl y decreases , allowing th e blowin g agen t t o volatilize . A s th e foame d polystyren e passe s throug hth e die , compresse d ai r i s applied , forming a ski no n th e oute r surfaces . Additiona l foamin g occur s outsid e th e di e a s th e polystyren e tub e passe s ove r a forming mandrel , whic hdetermine s th e fina l circumferenc e o f th e foa

mtub e (Step 5) . A t th e en d o f th e mandre l th e tub e i s spli t lengthwise , flattene d out , an d a n S-wrap , o r shee t wrapping unit , wind s th e shee t int o a rol l (Step 6) . Th e PS F shee t i s the n store d fo r tw o t o fiv e days . During thi s time , a portio no f th e blowin g agen t diffuse s ou t o f th e foa mcell s and i s replace d wit hair . Thi s result s i n a noptimu mrati o o f ai r t o blowing agen t withi n th e foamcells , whic hwil l allo wfo r postexpansio n o f th e PS F during thermoforming . Thermoformin g i s a proces s i nwhic hth e extrude d PS F shee t i s reheated , the n presse d betwee nth e tw o halve s o f a meta l moi d t o for m th e desire d en

d produc t suc ha s fast-foo d container s

13 4P.4 7

(Step 7) . Afte r thermoforming , th e molde d shap e i s trimmed , sometime s printed , and packaged . Resultin g scrap s ar e ground and sen t t o scrap storag e silos . Thi s scrap i s introduce d int o th e primaryextrude r wit hvirgi n polystyrene . Polystyren e scrap typicall ymake s u p 3 5 percen t o f th e tota l polystyren e fe d t o th e primaryextruder . Extrude d Polystyren e FoamBoard — Polystyren e foamboar d range s from1.2 5 t o 1 5 c m thick , wit h densitie s o f 2 7 t o 6 6 kg/m 3

. Th e extrusio no f P S foamboard s i s identica l t o tha t o f P S foamsheet s (Step 1 : mixin g P S pellet s wit hnecleating agent , Ste p 2 : primaryextrusion , Ste p 3 : secondaryextrusion) , wit hth e exceptio n tha t a simpl e sli t apertur e di e i s use d instea d o f a n annula r di e s o tha t boar d i s extrude d a s slab s rathe r tha n a tub e (Step 4) . Followin g coolin g o f th e P S board , i t i s trimme d t o siz e and packaged . Atypica l PS F boar d manufacturin g proces s flo wdiagrami s shown i n Figur e 26 . Some boar d i s laminate d wit hfacing material s tha t ac t a s a vapo r barrie r o r ai d i nth e retentio no f lo w conductivit ygas. 2 1 Expandabl e Polystyrene — Expandabl e polystyren e i s produce d fromspherica l polystyren e bead s whic hhav e bee n impregnate d wit ha volatil e hydrocarbo n suc ha s n-penten e o r CFC-12 . Th e polystyren e bead s ar e produce d b

ypolymerizin g styren e i n a wate r suspensio nand addin g i t t o a volatil e liqui d suc ha s n-pentane . Tha t serve s a s th e blowing agent . Th e bead s typicall ycontai n5 t o 7 weigh t percen t o f blowin g agent . Prio r t o use , th e bead s ar e store d a t temperature s belo w21* C (70°F ) t o inhibi t prematur e expansion. 2 2

Atypica l EP S bea d manufacturin g proces s flo wdiagrami s shown i n Figur e 27 . Normally , th e bead s ar e expande d i non e ste p



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and molde d i n another . Th e bead s ar e firs t expande d t o achiev e th e desire d moldin g densit y(Step 1) . Expansio ni s promote d by exposin g th e bead s t o a continuou s flo wo f steamo f ho t ai r a t temperature s o f 21 2 t o 220° F withi na proces s uni t calle d a pre expander . Th e amoun t o f expansio n i s controlle d b ystea m pressur e and temperatur e and th e bea d fee d rate. " Bot hbatc h and continuou s processe s ar e common . Th e transfe r o f hea t vaporize s th e volatil e hydrocarbo n trappe d i n th e polystyren e matrix . A s th e volatile s ar e release d fromth e matrix , th e bead s foaman d expand . Following th e expansio nprocess , th e exces s moistur e acquire d durin g th e steamin g i s eliminate d wit hho t ai r ^n d th e bead s ar e transporte d t o storag e silo s constructe d o f larg e mes h bags , wher e the yar e allowe d t o coo l (Step 2). " Th e bead s ar e allowe d t o ag e fo r 2 t o 7 2 hours , durin g whic htim e a portio no f th e remaining trappe d volatil e compound s evaporate s an d i s replace d wit hai r tha t diffuse s int o th e beads . Ai r mayb e pumpe d throughth e bead s t o accelerat e th e aging process . Onc e aged , th e bead s ar e place d i nmold s and stea mi s use d t o expand th e bead s (Step 3) . Ther e ar e thre e type s o f molding : shape , block , and cup molding. 2 2 I n shap e molding , a premeasure d amoun t o f expande d bead s i s fed t o a preheate d spli t cavit ymold . Th e bead s ar e expose d t o stea mthroughsmal l hole s i nth e mold . Th e bead s underg o furthe r expansion , becom e sof t and molte ndu e t o the ' transfe r o f hea t fromth e steam , and fus e togethe r unde r thes e condition s t o forma singl e polyme r mass . Following th e expansio n and fusin g process , th e mol d and PS F par t ar e coole d by circulating wate r throug hth e mold . Th e mol d i s the n opened , and th e molde d par t i s ejecte d bycompresse d air , mechanica l pins , o r manually . Shape-molde d polystyren e foa mproduct s hav e densitie s rangin g fro

m1. 0 t o 2. 5 lb/ft 3

. 2 3

I n bloc k molding , pre-expande d bead s ar e molde d int o larg e block s o f densitie s from 0. 8 t o 1. 0 lb/ft 3

. " Following cooling and intermediat e storage , block s ar e slice d int o sheet s o r custom 13 8P.5 1

fabricate d shapes . Cu p moldin g use s smalle r bead s an d lowe r blowin g agen t conten t tha n bloc k o r shap e molding . Cu p densit y i s ove r 3. 5 lb/ft 3

. " Cup s ar e molde d a t a moderat e temperature ; th e fina l produc t i s package d i n plasti c an d boxe d fo r shipping . Pos t moldin g operation s o f agin g (Ste p 4 ) an d fabricatio n (Ste p 5 ) ar e th e fina l step s befor e printin g an d shippin g o f th e product . Polystyren e Loos e Fil l Packaging — Polystyren e loos e fil l packagin g i s manufacture d wit ha combinatio n o f extrusio n an d bea d expansion . Recycle d an d ne w polystyren e ar e mixe d wit ha nucleatin g agen t an d melted , a s fo r extrusion . Th e blowin g agen t i s injecte d unde r pressure , an d th e viscou s mi xi s extruded , foamin g a s th e blowin g agen t evaporates , an d formin g hollo wstrand s a s i t exit s throug hth e die . Th e hollo wstrand s ar e cu t int o 3/4-inc hpieces . Th e strand s ar e the n steame d fo r furthe r expansion , a s ar e EP S beads . Intermediat e agin g follows , an d the n th e strand s ar e furthe r stea mexpanded , drie d i n ovens , an d aged . Th e densit yo f loos e fil l i s abou t 0. 2 lb/ft 3

. . 3 2 3 Emission s fro m

Polystyren e Foa mProductio n N o informatio n wa s locate d i n th e literatur e o n styren e emission s associate d wit hthes e processes . Th e reade r i s encourage d t o contac t individua l facilitie s i n questio n t o obtai n styren e emission s data .



### 13 9

### P.5 2

i 

### } REFERENCE S FO RSECTIO N6

1 . A . T . Kearney . Impac t Analysi s o f th e EP AOffic e o f Drinkin g Wate r Proposa l t o Regulat e Styrene . Styren e Informatio nResearc hCenter . 1989 . 2 . Clark , R. , e t al . Potentia l Environmenta l Impac t o f Compoundin g an dFabricatin g Industries : APreliminar y Assessment. EPA-600/2-77-160 . U . S . Environmenta l Protectio nAgency , Cincinnati , Ohio . 1977 . 3 . Pfaffi , P. , e t al . Degradatio nProduct s o f Homopolyme r Polystyren e i nAir . Scand . J . Wor k Environ . Healt h4 (suppl . 2) : pp . 22-27 . 1987 . 4 . Hoff , A. , e t al . Degradatio nProduct s o f Plastics : Polyethylen e andStyren e - Containin g Thermoplastic s - Analytical , Occupationa l andToxicologi c Aspects . Scand . J . Wor k Environ . Healt h8 (supp l 2) : p . 60 . 1982 . 5 . Lette r an denclosur e fro mTerr i Thomas , Ventur a Count y Resourc e Managemen t Agency , California , t o D . Campbell , Radia nCorporation . Jun e 27 , 1989 . ' 6 . Sprow , T . K . Unsaturate dPolyester . Moder nPlastic s Encyclopedia . pp . 48-50 . 1986-1987 . 7 . U . S . Environmenta l Protectio nAgency . Compilatio no f Ai r Pollutan t Emissio nFactors . AP-42 . U . S . Environmenta l Protectio nAgency , Researc hTriangl e Park , Nort hCarolina , p . 4.12- 1 - 4.12-12 . 8 . Randazzo , C , SP I Composite s Institute . Comment s o ndraf t "Locatin g an dEstimatin g Ai r Emission s fro mSource s o f Styrene " document . Decembe r 1990 . 9 . Stockton , M . B . andI.R . Kuo . Assessmen t o f VO C Emission s fro mFiberglas s Boa t Manufacturing . EPA-600/2-90-0019 . U . S . Environmenta l Protectio nAgency , Researc hTriangl e Park , Nort hCarolina . 1990 . 10 . Gibb s andCox , Inc . Marin e Desig nManua l fo r Fiberglas s Reinforce dPlastics . McGraw-Hil l Boo k Company , Ne wYork , Ne wYork . pp . 4-16 . 1960 . 11 . Thoma s Registe r o f America nManufacturers , Thoma s Publishin g Company , Ne wYork , Ne wYork . 1987 . 12 . Rogozen , M . B . Contro l Technique s fo r Organi c Ga s Emission s fromFiberglas s Impregnatio nandFabricatio nProcesses . Californi a Ai r Resource s Boar dRepor t No . ARB/R-82/165 . 1982 . 14QP.5 3

13 . Randazzo , C. , SP I Composite s Institute . Comment s o ndraf t "Locatin g and Estimatin g Ai r Emission s fromSource s o f Styrene " document . Augus t 1991 . 14 . Rogozen , M . B . Developmen t o f a n Inventoryo f Styren e Emission s from

Polyeste r Resin/Fiberglas s Fabricatio n i n California . In : Th e Ai r Pollutio nContro l Association , ed . ASpecialt yConferenc e o nEmissio nInventorie s and Ai r Qualit yManagement . Apri l 27-30 , Kansa s city , Missouri , pp . 363-378 . 1982 . 15 . Chemica l Profile ; Polystyrene . Chemica l Marketin g Reporter , Jun e 20:52 . 1988 . 16 . Resi n Repor t 1989 . Journa l o f Moder nPlastics , January , 1989 . 17 . Societ yo f th e Plastic s Industry . Membershi p Directory , 1989 . 18 . U . S . Environmenta l Protectio nAgency . Industria l Proces s Profile s fo r Environmenta l Use : Chapte r 10 . Prepare d b y Radia n Corporation , 1987 . 19 . Thoma s Registe r o f America nManufacturers . Thoma s Publishin g Company , Ne wYork , Ne wYork . 1988 . 20 . Kirk-Othme r Encyclopedi a o f Chemica l Technology . 3rd ed . Styren e Polymers . Volum e 16 . John Wileyand Sons . Ne w York , Ne wYork . pp . 148-245 . 1979 . 21 . Foundatio n Desig n Handbook : Volum e 1 . Undercurren t Desig n Research . Underground Spac e Center , Universit yo f Minnesota . 22 . Rodriquez , F . Principle s o f Polyme r Systems . McGraw-Hill , Inc. , Ne wYork , Ne wYork , 1970 . 23 . Tsitsopoulas , L . and M . Mills . Staf f Report , Propose d Rul e 1175 : Contro l o f Emission s from th e Manufactur e o f Polymeri c Cellula r Product s (Foam) . Sout hCoas t Ai r Qualit y Managemen t District ; Rul e Developmen t Division , September , 1989 .

14 1P.5 4

14 2P.5 5

SECTION7 SOURC E TES T PROCEDURE S Styren e emission s ca nb e measure d b ysevera l methods , five o f whic hare : (1 ) EPAReferenc e Metho d 18 , whic hwa s announce d i n th e Federa l Registe r o n Octobe r 18 , 1983; \ (2 ) NIOS H Analytica l Metho d 150 1 publishe d i nth e NIOS H Manua l o f Analytica l Method s o n Februar y15 , 1984 ; 2 (3 ) EP A Method504 0 whic hwa s publishe d i n EPARepor t No . SW-84 6 i nNovembe r 1986; 3 (4 ) CompendiumMetho d TO-14 , determinatio n o f volatil e organi c compound s (VOCs ) i n ambien t ai r usin g caniste r sampling; 4 an d (5 ) EP AReferenc e Metho d 8270. s

EP AReferenc e Metho d 1 8 applie s t o th e samplin g and analysi s o f approximatel y9 0 percen t o f th e tota l gaseou s organic s emitte d froma n industria l source ; wherea s NIOS H Metho d 150 1 applie s onl y t o th e collectio n an d analysi s o f te nspecifi c aromati c hydrocarbons . Ametho d simila r t o th e NIOS H Metho d 150 1 i s th e America n Societ yfo r Testin g and Material s (ASTM ) D 3686-8 4 metho d (publishe d o n Jun e 29 , 1984). 6 EPAMetho d 504 0 applie s t o th e analysi s o f TENAX ®and TENAX®/charcoa l cartridge s use d t o collec t volatil e principa l organi c hazardou s constituent s (POHCs ) fromwe t sta g ga s effluents . Compendium Metho d TO-1 4 i s applicabl e t o specifi c VOC s tha t hav e bee nteste d and determine d t o b e stabl e whe n store d i n pressurize d and sub-atmospheri c pressur e canister. * EPAMetho d 827 0 i s use d t o determin e th e concentratio n o f semivolatil e organi c compound s usin g ga s chromatography/mas s spectrometry(GC/MS) . EP AREFERENC E METHO D 1 8
I n Metho d 18 , a sampl e o f th e exhaus t ga s t o b e analyze d i s drawn int o a Tedlar® o r aluminize d Mylar®bag ; a s shown i n Figur e 28 . Th e ba g i s place d insid e a rigid , leakproof;containe r



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and evacuated . Th e ba g i s the n connecte d bya Teflon ®sampling lin e t o a samplin g prob e (stainles s steel , Pyrex ®glass , o r Teflon® ) a t th e cente r o f th e stack . Th e sampl e i s drawn int o th e ba g b

ypumpin g ai r ou t o f th e rigi d container . Th e sampl e i s the n analyze d byga s chromatography(GC ) couple d wit hflam e ionizatio ndetectio n(FID) . Base d o n fiel d an d laboratorystudies , th e recommende d tim e limi t fo r analysi s i s withi n 3 0 day s o f sampl e collection. 7 * * Th e G C operato r shoul d selec t th e colum

n and G C condition s tha t provid e goo d resolutio n and minimu

manalysi s tim e fo r styrene . Zer o heliu mo r nitroge n shoul d b e use d a s th e carrie r ga s a t a flo wrat e tha t optimize s th e resolution . Th e pea k area s correspondin g t o th e retentio ntime s o f styren e ar e measure d and compare d t o pea k area s fo r a se t o f standar d ga s mixture s t o determin e th e styren e concentrations . Th e detectio n limi t o f thi s metho d range s fromabou t 1 par t pe r millio n (ppm ) t o a n uppe r limi t governe d b yth e FI D saturatio no r colum n overloading . However , th e uppe r limi t ca nb e extende d b y dilutin g th e stac k gase s wit hth e iner t ga s o r b yusin g smalle r ga s sampling loops . Whe n acces s t o th e samplin g locatio n i s difficult , a n alternativ e samplin g metho d describe d i nSectio n7. 4 o f EPA Referenc e Metho d 1 8 mayb e preferred. * NIOS H METHO D 150 1

, Thi s metho d ha s limite d application . . Th e metho d applie s onl yt o te n specifi c aromati c hydrocarbons . Severa l necessary modification s are . recommende d i f thi s metho d i s t o b e used. 9

I n th e NIOSiH method , sample s ar e collecte d wit hsoli d sorben t tube s containin g coconu t shel l charcoal . Fiv e t o 14

- lite r ai r sample s ar e collecte d wit hth e us e o f a persona l sampling pum

p a t a known flo wrat e o f < 1 L/minute. 2 14 5P.5 8

Sample s ar e desorbe d wit hcarbo ndisulfid e an d analyze d by G C equippe d wit ha n FI D and a colum ncapabl e o f resolving styren e fromth e solven t fron t and othe r interferences . Th e colum n specifie d i n NIOS H Metho d 150 1 isa3.0mx2m mglas s o r stainles s steel , 10 % OV^27 5 o n 100/12 0 mes hChromosorb ®W-AW , o r equivalent. 2 Th e amoun t o f styren e i na sampl e i s obtaine d from th e calibratio n curv e i n unit s o f milligram s pe r sample , storag e stabilit yha s no t bee n assesse d fo r thi s method , thus , analysi s shoul d occu r a s soo n a s possibl e followin g sampl e collection . Styren e ca n dimeriz e durin g handling and storage . The " rat e o f dimerizatio n i s a functio no f temperature , increasing a s th e temperatur e increases . Consequently , sample s shoul d b e store d a t lo wtemperatures . Thi s procedur e i s applicabl e fo r monitorin g styren e ai r concentration s .ranging from 2.1 7 t o 8.4 9 mg . Th e GC colum nand operatin g condition s should 1 provid e goo d resolutio nan d minimu

m analysi s time . EPAMETHO D 504 0

I n Metho d 5040 , a sampl e o f stac k ga s i s collecte d o n TENAX ® and T.ENAX®/charcoa l sorben t cartridge s usin g a volatil e organi c sampling train , (VOST). 3 Becaus e th e majorit yo f ga s stream s sample d using VOS T wil l contai na highconcentratio no f water , th e analytica l metho d i s base d o n th e quantitativ e therma l desorptio n o f volatil e POHC s fromth e TENAX ®an d TEN.AX®/charcoa l traps . Th e analysi s i s b ypurge-and-trap GC/MS.

Aschemati c diagramo f th e analytica l systemi s show ni n Figur e 29 . Th e content s o f th e sorben t cartridge s ar e spike d



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wit ha n interna l standard , thermall ydesorbed , an d trappe d o na n analytica l adsorben t trap directe d int o th e GC/MS . Th e volatil e POHC s ar e separate d b ytemperature-programme d GC an d detecte d by low-resolutio n mas s spectrometry . Th e concentration s o f volatil e POHC s ar e calculate d usin g th e interna l standar d technique . Sampl e train s obtaine d fromth e VOS T shoul d b e analyze d withi ntw o t o si xweek s o f sampl e collection . Th e desire d targe t detectio nlimi t o f thi s metho d i s 0. 1 ng/ L (2 0 n g o n a singl e pai r o f traps) . Industryexperienc e ha s found thi s metho d t o b e difficul t t o us e and easil y overloade d whe n th e analyt e concentratio ni s i n th e hig hpart s pe r billio n (ppb ) t o pp mrange. 1 0 I naddition , th e cost " associate d wit hthi s metho d i s highe r tha n othe r analytica l methods. *

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MMETHO D TO-1 4 Metho d TO-1 4 i s base d o ncollectio n o f whol e ai r sample s i n SUMMA ®passivate d stainles s stee l canister s fo r analysi s o f volatil e organi c compound s (VOCs ) i nambien t air . Asampl e o f ambien t ai r i s drawn througha samplin g trai ncompose d o f component s tha t regulat e th e rat e and duratio n o f samplin g int o a pre-evacuate d SUMMA ®passivate d canister . Th e VOC s ar e separate d b yG C and measure d b ymass-selectiv e detector s o r multidetecto r techniques . Th e recommende d tim e limi t fo r analysi s i s withi n1 4 day s o f sampl e collection. 1 0 Th e colum n specifie d i n Compendiu mMetho d TO-1 4 i s a Hewlet t OV- 1 capillarycolumn , 0.3 2 m mI.D . x5 0 mwit h0.8 8 umcross-linke d methy l silicon e coating , o r equivalent. 4 Th e wide r J & W Scientifi c Compan

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### 14 8P.6 1

Thi s metho d i s designe d fo r ambient , no t sourc e monitoring . Fe wlaboratorie s offe r i t an d i t i s quit e costly . I t i s reportedl ydifficul t t o us e an d th e sampl e ma yb e easil y contaminate d b yth e system . Recover yrate s fo r reactiv e compound s ten d t o b e ver ylow. '

EP AREFERENC E METHO D 827 0 Metho d 827 0 describe s condition s fo r GC/M S an d i s use d t o determin e th e concentratio n o f semivolatil e organi c compound s i n extract s prepare d fro mal l type s o f soli d wast e matrices , soils , an d groun d water . Th e analytica l methodolog ywil l b e equall y applicabl e t o a n extrac t fro msorben t medi a use d i n conjunctio n wit hEP AMetho d 001 0 t o sampl e stationar ysources . Th e sorben t fo r Metho d 001 0 i s XAD-2 ®resi n whic hi s a styrene-divinylbenzen e copolymer . Styren e monome r ma yals o b e presen t i n th e resi n an d ma yresul t i n interferences . Adifferen t sorben t shoul d be , substitute d fo r XAD-2® . Tw o possibl e candidate s ar e TENAX® , whic hwoul d requir e extractio n wit hpentan e o r hexane , an d XAD-7 ® whic hi s a n acryli c resin . Extractio n efficiencie s woul d nee d t o b e validate d befor e thes e modification s ar e accepted . Styren e i s withi n th e boilin g poin t rang e fo r analysi s by Metho d 8270 , bu t i s sufficientl yvolatile . Car e mus t b e take n i n sampl e concentratio n t o avoi d loss . A n adjustmen t i n chromatographi c condition s wil l b e require d t o resolv e th e relativel yvolatil e styren e fro mth e solvent . Th e practica l quantitatio n limi t fo r Metho d 827 0 i s approximatel y5 0 ug/m L o f extract . Th e entir e sorben t modul e wit hfilte r i s typicall yextracte d an d concentrate d t o a fina l volum e o f 1 mL . Thi s fina l extrac t volum e represent s th e entir e volum e o f ga s sampled .



### 14 9P32^

REFERENCE S FORSECTION7 1 . 4 0 CF RPar t 60 , Appendi xA , Metho d 18 : Measuremen t o f Gaseou s Organi c Compound Emission s b yGa s Chromatography , pp . 868 , 873-878 , 886 , 889 , 895 . Jul y1 , 1989 . 2 . U . S . Departmen t o f Health , Education , an d Welfare . NIOS H Manua l o f Analytica l Methods , 3r d ed. , Volume 2 . Nationk l Institut e fo r Occupationa l Safet yan d Health , Cincinnati , Ohio . pp . 1501- 1 t o 1501-7 . 1984 . 3 . Metho d 5040 : Protoco l fo r Analysi s o f Sorben t Cartridge s fro mVolatil e Organi c Samplin g Train . Tes t Method s fo r Evaluatin g Soli d Waste , 3r d ed. , Vol . IB : Laboratory Manual , Physical/Chemica l Methods . EPARepor t No . SW-846 . Novembe r 1986 . 4 . Compendiu

mMetho d TO-14 : Th e Determinatio no f Volatil e Organi c Compound s (VOCs ) i nAmbien t Ai r Usin g Summa® Passivate d Caniste r Samplin g and Ga s Chromatographi c Analyses . Qualit yAssuranc e Division . Atmospheri c Researc h and Exposur e Assessmen t Laboratory , U . S . Environmenta l Protectio n Agency , Researc hTriangl e Park , Nort hCarolina , pp . 1-15 , 18,19 , 21-23 . Ma y1988 . 5 . U . S . Environmenta l Protectio nAgency , Offic e o f Soli d Wast e and Emergenc yResponse . Metho d 8270 : Ga s Chromatography / Mas s Spectrometryfo r Semivolatil e Organics : Capillary Colum n Technique . Tes t Method s fo r Evaluating Soli d Waste , 3r d ed . Repor t No . SW-846 . Washington , D.C . 1986 . 6 . AST MD3686-84 . .Annua l Boo k o f AST MStandards , Volum e 11.03 . 1984 . 7 . Persona l Communication. l

- Moody , T . K. , Radia nCorporation , wit hHartman , M. , Radia n Corporation , Octobe r 9 , 1989 . Discussio n o f styrene/butadien e stac k sampling and analysis . 8 . Persona l Communication . Moody , T . K. , Radia nCorporatio n wit hPau , J. , U . S . Environmenta l Protectio nAgency , Atmospheri c Researc han d Exposur e Assessmen t Laboratory , Octobe r 10 , 1989 . Discussio no f EP AReferenc e Metho d 1 8 i n relatio n t o styren e stac k sampling . 9 . Randazzo , C., . SP I Composite s Institute . Comment s o ndraf t "Locatin g and Estimating Ai r Emission s fromSource s o f Styrene " document . Decembe r 1990 . 10 . Persona l Communication . Moody , T . K. , Radia nCorporation , wit hRice , J. , Radia n Corporation , February7 , 1990 . Discussio n o f Compendiu mMetho d TO-14 .

15 0P.6 3

TECHNICA L REPOR T DAT A | (Please read

Instructions on r*

#reverse before completing) I . REPOR TNO ; 4 . TITL E ANO^STITL E 2 . Locatin g and Estimating Ai r Emission s From Source s o f Styrene , Interi m Repor t 7 . AUTHOR(S ) 8 . PERFORMIN G ORGANIZATIO N REPOR TNQ . Darc yCampbel l 9 . PERFORMIN G ORGANIZATIO N NAM E AN O ADDRES S Radia n Corporatio n Pos t Offic e Bo x1300 0 Researc hTriangl e Park , Nort hCarolin a 2770 9 3 . RECIPIENT' S ACCESSIO N NO . 5 . REPOR TOAT E Octobe r 199 1 6 . PERFORMIN G ORGANIZATIO N COD E

10 . PROGHA M ELEMEN TNO . 1 . CONTRACT/GRAN TNO . 68-DO-012 5 12 . SPONSORIN G AGENC YNAM E AN O AOORES S Technica l Suppor t Divisio n OAR , OAQPS , TSD , EFM S (MD-14 ) Emissio n InventoryBranc h P^^TT- H Tytamyi P Park . Nort hCarolin a 2771 1 13 . TYP E O F REPOR TAN O PERIO O COVERE D Tnt-p-i- i i n 14 . SPONSORIN G AGENC YCOD E

IS . SUPPLEMENTAR YNOTE S EPAProjec t Officer : Ann e A . Pop e

16 . ABSTRAC T . T o assis t group s intereste d i n inventoryin g ai r emission s o f variou s potentiall ytoxi c substances , EP Ai s preparin g a serie s o f document s suc ha s thi s t o compil e availabl e informatio n o n source s an d emissio n o f thes e substances . Thi s documen t deal s specificall ywit hstyrene . It s intende d audienc e include s Federal , Stat e and loca l ai r pollutio n personne l and other s intereste d i n locatin g potentia l emitter s o f styren e an

d i n making gros s estimate s o f ai r emission s therefrom . Thi s documen t present s informatio n o n (i ) th e type s q f source s tha t mayemi t styrene , (2 ) proces s variation s an d releas e point s tha t ma y b e emitte d withi n thes e sources , an d (3 ) availabl e emission s informatio n indicating th e potentia l fo r styren e release s int o th e ai r fromeac hoperation . Thi s documen t i s bein g release d a s a n interi mdocumen t pendin g incorporatio n o f testin g result s from th e U.S . EPA . Th e EP Ai s currentl ytesting severa l unsaturate d polyeste r resi nfabricator s wh o produc e culture d marbl e bathroo mfixtures . Whe n th e tes t result s ar e iilablo , tha FP

Awil l publis ha fina l repor t inclurlin g th^s e data . -av-a ; 17 . KE YWORO S AN O OOCUMEN TANALYSI S DESCRIPTOR S b,IOENTIFIERS/OPE NENOE O TERM S C . COSAT IField/Grou p Styren e Ai r Emission s Source s Locatin g Ai r Emission s Source s Toxi c Substance s

18 . DISTRIBUTIO N STATEMEN T 19 . SECURIT Y CLAS S (Tltis Reportf 2 1 . NO . O F PAGE S 

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