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# OAR Box 1846 Prepped byOllie Stewart



### Document

Number: 

# 11 ) ll-B- 8 Docket Number: 

# A-90-0 7

Printed 11/18/20087:30:14AM Sheet 11 of 93P. 2

A" ^ t0Sr « * . '*' * ^ *T , UNITE D STATE S ENVIRONMENTA LPROTECTIO N AGENC Y 

# vss y MA R2 41992

MEMORANDU M AN N ARBO.S—MJ£,fcHlGAN-.4S4^ S



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OFFIC E O F AI R AN O RADIATIO N

SUBJECT :
FROM :
TO : THRU : APreconditionin g Cycl e fo r Potentia l Us e

Fuel s an d Fue l Additive s Registratio nProgra m i n th e
Jame s D . Greaves, , Mechanica l Enginee r Standard s Developmen t an d Suppor t Branc h Docke t Numbe r A-90-0 7 Judit hGray , Projec t Manage r Standard s Developmen t an d S 

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Glen nW

. Passavant , Senio r Projec t

Manage r

. Standard s Developmen t an dSuppor t

Branchrr/l^^t/ M Cheste r J
. France , Chie f

I^/l/l^ Standard s Developmen t andiMupj/ort

Branc h Summary Thi s memorandu m

contain s a descriptio no f a vehicl e operatio n cycl e intende d t o significantl yreduc e short-ter memissio n carryove r effect s fro mfuel s an d fue l additives . Th e cycl e coul d b e use d durin g emission s generatio n fo r healt han d emissio neffect s testin g unde r th e propose d change s t o EPA' s Fuel s an d Fue l Additive s Registratio n program . I n addition , long-ter memissio n carryove r effect s fro mfuel s an d additive s previousl yuse d i n tes t vehicle s ar e als o examined . Backgroun d A s par t o f th e propose d Fuel s an d Fue l Additive s Registratio n progra m

implementin g Sectio n211(b)(2 ) o f th e Clea nAi r Act , combustio nan d evaporativ e emission s fro mmoto r vehicl e fuel s an d fue l additive s woul d b e generate d an d teste d t o determin e thei r compositio nan d effect s o nhuma nhealth . EP Ai s initiall y proposin g tha t onl yne wvehicle s woul d b e eligibl e fo r generatin g emission s fo r testin g an d tha t a give ntes t vehicl e woul d onl yb e operate d o nth e particula r fuel/additiv e unde r evaluation . However , othe r alternativ e proposal s ar e unde r consideration . On e alternativ e woul d allo wuse d vehicle s acquire d fro mth e in-us e U.S . flee t t o b e eligibl e a s tes t vehicles . Anothe r alternativ e woul d permi t tes t vehicle s t o b e use d t o generat e emission s fo rP. 3

mor e tha non e tes t fue l o r additive . Thes e method s woul d hav e th e advantag e o f requiring les s resource s tha ni f ne wvehicle s ar e require d fo r eac hproduc t tested . However , unrelate d emission s may potentiall yb e introduce d du e t o "carryove r effects " fromproduct s previousl yuse d i nth e vehicle . Thi s memorandu mdescribe s potentia l emissio ncarryove r effect s and present s a vehicl e operatio ncycl e intende d t o minimiz e carryove r emission s i nth e even t tha t in-us e vehicle s ar e permitte d t o generat e emissions , o r tha t tes t vehicle s ar e permitte d t o b e use d t o generat e emission s fo r mor e tha non e product , o r both . Emissio n Carryove r Effect s Afuel' s o r additive' s emissio ncarryove r effect s canb e "short-term " o r "long-term" . Short-termcarryove r effect s resul t fro mth e presenc e o f th e previousl yuse d rawproduc t o r combustio n emission s i n th e fue l system(i.e. , fue l tank , fue l pump , transfe r lines , filters , injectors , 8tc.) r evaporativ e emissio ncontro l system(i.e. , canister , transfe r lines , purg e valves , etc.) , and/o r engine/exhaus t system(i.e. , engine , exhaus t manifold , exhaus t pipes , oxyge nsensor , catalyti c converter , muffler , etc.) . Fo r mos t fuel s o r fue l additives , i t i s postulate d tha t rawo r combuste d produc t tha t remain s i nth e system s woul d no t permanentl y affec t th e emission s o f th e vehicle . Therefore , remova l o f short

termcarryove r effect s essentiall yrequire s "rinsing out " thes e system s b

yoperating themfo r a sufficien t amoun t o f tim e o n th e ne wproduct . Long-term

carryove r effect s ar e relate d t o modification s o r damag e t o a vehicle' s component s cause d b yth e produc t o r it s emissions . Long-term carryove r effect s includ e produc t deposit s on fue l injector s an

d intak e valve s an d combustio nemissio ndeposit s o nth e combustio nchamber , oxyge nsensor , and catalyti c converter . Also , a canister' s performanc e canb e degrade d byth e introductio n o f larg e amount s o f difficult-to-purg e evaporatio nproduct s int o th e activate d carbon . Long-termcarryove r effect s typicall yoccu r ove r extende d period s o f time an d canhav e larg e affect s o nth e emissio ncharacteristic s o f th e vehicle , eve nafte r th e produc t use d i nth e vehicl e i s changed . Short-Term

Carryove r Effect s Th e preconditionin g sequenc e tha t ha s bee nidentifie d t o addres s short-termcarryove r effect s i s entitle d th e "Intermediat e Preconditionin g Cycle" . The Intermediat e Preconditioning Cycl e i s intende d t o remov e previousl yuse d fue l an d emission s fro

ma vehicle' s fuel , exhaust , an d combustio nan

d evaporativ e emissio n contro l systems . Ates t vehicl e tha t ha s use d a fue l o r additiv e othe r tha nth e intende d tes t produc t woul d nee d t o performthi s cycl e befor e usabl e emission s coul d b e generate d fromth e ne wtes t product . Th e cycl e coul d b e performe d anytime befor e emission s ar e generate d usin g th e ne wtes t product . However , onc e th e Intermediat e Preconditionin g Cycl e ha s bee nperformed , th e vehicl e woul d nee d t o us e th e tes t fue l o r additive/fue l combinatio nP. 4

exclusively , o r els e th e Intermediat e Preconditioning Cycl e woul d nee d t o b e repeated . Th e Intermediat e Preconditioning Cycle , show ni nFigur e 1 , i s base d o na preconditionin g sequenc e propose d b yEPA' s Offic e o f Researc han

d Development , Mobil e Sourc e Emission s Researc hBranch . Thei r cycl e wa s develope d fo r us e i n a vehicl e emission s an d fue l econom ystud yfo r th e U.S . Departmen t o f Energy , wher e i t serve s a simila r purpose . Th e Intermediat e Preconditioning Cycl e contain s on e fue l drai nan

d complet e fue l fil l an d a minimu

mo f on e fue l drai nan

d 4 0 percen t fue l fill , which , whe naccompanie d wit hth e fue l drai nand 4 0 percen t fue l fil l require d i nth e preconditioning sequenc e o f th e Federa l Tes t Procedur e (FTP) , bring s t o thre e th e minimu mnumbe r o f time s th e fue l tank woul d b e rinse d wit hth e ne w tes t produc t befor e emissio ngeneratio ncoul d begin . Th e nee d fo r additiona l fue l drain s an d fills , du e t o evaporativ e emissio n caniste r loading performance , i s explaine d i na succeeding sectio n o f thi s memorandum . During th e Intermediat e Preconditioning Cycl e th e tes t vehicl e i s operate d unti l 9 5 percen t o f a tank o f fue l ha s bee nconsumed . Alight-dut ygasolin e fuele d vehicl e woul d accumulat e approximatel y 35 0 mile s o f driving fromthi s amoun t o f fuel . Alimite d amoun t o f additiona l vehicl e operatio nwoul d als o b e encountere d during th e preconditionin g phas e o f th e FT P prio r t o emissio ngeneration . Th e fue l change s an

d vehicl e operatio nrequirement s o f th e Intermediat e Preconditioning Cycl e ar e expecte d t o remov e short-termcarryove r effect s fromth e fue l deliverysysteman d fro mth e engine/exhaus t system . Evaporativ e Emissio nCaniste r Conditioning Th e effect s o f previousl yuse d fuel s and/o r additive s ona vehicle' s evaporativ e emissio ncontro l systemar e expecte d t o b e thoroughl yremove d b yth e vehicl e operatio nan d benc hpurg e sequence s o f th e Intermediat e Preconditioning Cycle . Th e benc h purg e sequenc e woul d b e performe d onl yo n vehicle s equippe d wit h evaporativ e emissio ncontro l canisters . During th e benc hpurg e sequence , th e caniste r i s remove d fro mth e vehicl e and purge d wit h 30 0 F nitroge na t 2 0 liters/minut e unti l th e caniste r lose s les s tha non e gramo f weigh t i n3 0 minutes . Th e purg e proces s require s approximatel y3- 4 hour s fo r a lat e mode l light-dut ygasolin e fuele d vehicl e an

d remove s approximatel y100-12 0 gram s o f adsorbe d material . Thi s amoun t o f purg e i s expecte d t o remov e th e vas t majorit yo f organi c materia l adsorbe d ont o th e caniste r materia l an d thereb

yretur nth e caniste r t o muc hth e same stat e i t wa s i n whe ni t wa s new . An yfuel ' o r additive-relate d materia l remaining i nth e caniste r a t completio no f th e benc hpurg e sequenc e woul d b e unlikel yt o b e remove d during vehicl e operation . Th e purge d caniste r i s late r installe d o nth e tes t vehicl e an d reloade d wit hvapor s produce d b yth e ne wtes t fue l o r additive/fue l mixture . Caniste r loading i s performe d i n a Seale d Housin g fo r Emissio nDeterminatio n(SHED ) throughth e performanc e o f 72-12 0 F ,P. 5



## Figur e 1 - Th e Intermediat e Preconditionin g Cycl e

* Remov e th e caniste r fro mth e vehicl e an

d purg e i t wit h300 ° F nitroge na t 2 0 1/mi n unti l th e incrementa l weigh t los s o f th e caniste r i s les s tha n 1 gra mi n3 0 minute s (thi s typicall ytake s 3

- 4 hour s an

d remove s 10 0 t o 12 0 gram s o f adsorbe d gasolin e vapors) . * Drai nth e fue l tank an d fil l i t t o capacit ywit hth e tes t fue l o r additive/fue l mixture . * Operat e th e vehicl e unti l a t leas t 95 % o f th e fue l tank capacit yi s consumed . * Retur n th e "purged " caniste r t o th e vehicle . * Drai n th e fue l tank and fil l i t t o 40 % capacit ywit htes t fuel . * Perform72 « t o 120 ° F , 2-hour fue l tank hea t build s repeatedl y a s necessaryt o achiev e caniste r breakthrough(drai nan d fil l prio r t o eac hhea t build) .P. 6

tw o hou r hea t build s unti l "breakthrough " occurs . I f breakthrough doe s no t occu r during th e firs t hea t build , additiona l hea t build s ar e performe d usin g fres hfue l eac htim e unti l breakthroughoccurs . Anothe r optio nfo r caniste r preconditioning i s t o replac e th e vehicle' s caniste r wit ha ne wcanister . I nthi s wayon e coul d b e assure d tha t ther e woul d b e n o carryove r effect s fro mpreviousl y use d fuel s an

d additives . The ne wcaniste r woul d b e purge d an d loade d a s describe d above prio r t o installatio ni n th e tes t vehicle . EP Arequest s commen t onth e us e o f ne wcanister s fo r thi s purpose . I f adopte d fo r us e i nth e program , th e Intermediat e Preconditioning Cycl e woul d b e performe d o na tes t vehicl e anytime afte r th e tes t produc t i nth e vehicl e ha s bee nchange d an d befor e emission s ar e generate d usin g th e ne wtes t product . O f course , additiona l vehicl e operatio ncoul d b e performe d afte r th e Intermediat e Preconditioning Cycl e ha s bee ncomplete d t o furthe r conditio nth e vehicl e wit hth e ne wtes t product , i f s o desired . Additiona l vehicl e operation , a s wit hal l us e o f th e tes t vehicl e othe r tha n tha t specificall yprescribed , woul d b e don e wit hth e vehicl e unmodifie d (e.g. , th e caniste r coul d no t b e remove d fo r furthe r benc hconditioning) . Long-TermCarryove r Effect s - Use d Vehicle s Acquire d fromth e In
Us e Flee t Assessin g long-termcarryove r effect s from a vehicl e generall y require s a significan t amoun t o f effort . Firs t i t mus t b e determine d i f an

d wher e a problem

ha s occurred , and the na mean s mus t b e develope d t o addres s th e problem . Replacin g damage d component s mayalte r a vehicle' s emissio ncharacteristic s s o tha t "correct " emission s (i.e. , emission s tha t woul d hav e bee ngenerate d i f th e long-termcarryove r effec t wa s no t present ) mayneve r b e properl yrecovered . Thus , avoiding th e nee d t o addres s long-term carryove r effect s woul d b e preferable . I norde r t o assur e tha t vehicle s acquire d fromth e in-us e flee t and intende d t o generat e emission s fo r th e Fuel s an d Fue l Additive s programar e fre e fromlong-termcarryove r effects , comprehensiv e record s concerning th e candidat e vehicl e mayb e required . Thes e migh t includ e complet e and accurat e record s o f fue l use , aftermarke t fue l additiv e use , and vehicl e maintenance . Eligibl e vehicle s coul d b e limite d t o thos e wit ha historyo f consisten t us e o f deposi t contro l additive s an d whic hwer e use d onl ywit hproduct s unlikel yt o caus e long-termcarryove r effect s fro memission s (e.g. , contai nn o atypica l elements) . Ahistoryo f vehicl e maintenanc e according t o th e owner' s manua l woul d b e required . Also , preliminarycharacterizatio no f th e emission s generate d fromcandidat e vehicle s migh t b e require d t o verif ytha t theyar e reasonabl ywithi nexpectatio nan d ar e stabl e wit htime . Eve nwit hthes e precautions , th e manufacturer s mus t assume th e ris k tha t long-term

carryove r effects , whic hwer e undetecte d whe nth e vehicl e wa s screene d an d tested , migh t affec t th e emission s i naP. 7

negativ e way . Wit hal l o f thes e requirements , adde d t o th e fac t tha t th e vehicl e mus t b e o f th e prope r model , mode l year , an d vehicl e configuration , i t mayb e easie r t o purchas e ne wvehicle s an d accumulat e mileag e tha n t o fin d an d verif ysuitabl e in-us e vehicle s fo r th e program . Long-TermCarryove r Effect s - Vehicle s Use d t o Tes t Mor e Tha nOn e Produc t Anothe r alternativ e bein g considere d fo r th e Fuel s an d Fue l Additive s Registratio nprogramwoul d allo wvehicle s t o generat e emission s fo r mor e tha non e tes t product . Unde r thi s alternative , i f a tes t vehicl e wa s use d t o generat e emission s fo r tes t product s compose d o f onl ycarbon , hydrogen , nitrogen , oxygen , and/o r sulfur , concern s regarding long-termeffect s shoul d b e minima l and i t woul d b e reasonabl e t o allo wth e vehicl e t o generat e emission s fo r othe r tes t product s afte r performin g th e Intermediat e Preconditioning Cycle . I f th e tes t vehicl e wa s use d t o generat e emission s fo r a produc t tha t containe d an yelemen t othe r tha nth e five liste d abov e (i.e. , containe d an"atypica l element") , concern s regarding long

termeffect s woul d hav e t o b e addressed . I n thi s cas e i t woul d appea r t o b e les s pruden t t o allo wthes e vehicle s t o generat e emission s fo r othe r product s fo r th e Fuel s an d Fue l Additive s Registratio nprogram . A s wit hvehicle s acquire d fro mth e in-us e fleet , vehicle s whic hwer e previousl yuse d fo r testing i nthi s program shoul d b e fre e fromlong-term carryove r effect s i f the yar e t o b e use d fo r furthe r emissio ngeneration . I nthi s case , th e questio nbecome s whethe r long-termcarryove r effect s ca n occu r whil e a vehicl e i s use d t o generat e emission s fo r emissio ncharacterizatio nan d biologica l testin g purposes . T o generat e emission s fo r emissio n characterizatio npurpose s woul d probabl yrequir e les s tha n5 0 mile s o f driving . Emission s fo r biologica l testing woul d requir e a t leas t 6,30 0 mile s fo r light-dut yvehicl e driving an d ove r 33 0 hour s o f heavy-dut yengin e operation . Th e primarylong-termcarryove r effect s identifie d hav e bee n fue l deposit s o nth e fue l injector s an d intak e valves , an d combustio ndeposit s i n th e engin e an d o nexhaus t emissio ncontro l systems . However , th e formatio no f fue l injecto r an d intak e valv e deposit s during emissio ngeneratio nwoul d b e unlikely , sinc e th e bas e fue l wit hwhic hadditive s ar e mixe d i s require d t o contai na deposi t contro l additiv e (for gasolin e fuels) . Also , almos t al l o f th e gasolin e fuel s sol d i nthi s countrycontai ndeposi t contro l additives . Muc ho f th e ris k o f long-termcarryove r effect s fro m exhaus t emissio ndeposit s canb e avoide d i f vehicle s whic hgenerat e emission s fo r fuel s an d additive s tha t contai natypica l element s ar e no t permitte d t o generat e emission s fo r othe r tes t products . Thus , th e programcanb e structure d s o tha t i t i s unlikel y tha t long-termemissio ncarryove r effect s woul d occu r whil e aP. 8

vehicl e i s bein g use d t o generat e emission s fo r thi s program . However , wit hth e larg e numbe r o f product s and th e wid e rang e o f potentia l effect s the ycanhav e o na vehicle , i t canno t b e assure d tha t ther e woul d b e n o short ' o r long-termcarryove r effect s create d during emissio ngeneration . Anyris k o f emissio ncarryove r effect s involve d wit husin g vehicle s previousl yuse d t o tes t othe r product s woul d hav e t o b e assume d b yth e fue l o r additiv e manufacturer .