use of methanol as a transportation fuel · e. octane value ... use of methanol as a transportation...

Use of Methanol as a Transportation Fuel

Prepared for:

The Methanol Institute4100 North Fairfax Drive

Suite 740

Arlington, VA 22203

November 2007

Prepared by:

Richard L. Bechtold

Marc B. Goodman

Thomas A. Timbario

Alliance Technical Services Inc.10816 Town Center Blvd., #232

Dunkirk, MD 20754

Table of ConTenTsNovember 2007

Use of MeTHanol as a TRansPoRTaTIon fUel

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Table of Contents

I. ExecutiveSummary..................................................................1II. Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3III. MethanolBlendRegulation...........................................................4

A. UnitedStates ....................................................................41. EPAWaiversGrantedandOxygenateAllowancesas“SubstantiallySimilar”. . . . . . . . .42. EPADenials/RevocationsofWaiversatHighAlcohol/OxygenLevels. . . . . . . . . . . . . . .63. UseofMethanolinU.S.Fuels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

B. UseofMethanolBlendsintheEuropeanUnion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8IV. MethanolUseinFlexibleFuelVehicles. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9V. MethanolBlendPhysicalandChemicalPropertyImpacts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12

A. VaporPressure.................................................................12

B. WaterTolerance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13

C. MaterialsCompatibility .........................................................14

D. OxygenContent. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

E. OctaneValue...................................................................18

VI. MethanolBlendVehicleOperationalImpacts...........................................19A. Cold-Start .....................................................................19

B. Driveability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

C. Acceleration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

D. FuelEconomy ..................................................................21

VII. EmissionsImpacts ..................................................................22A. PrimaryRegulatedExhaustEmissions.............................................22

B. CarbonDioxideEmissions .......................................................24

C. Toxics .........................................................................25

D. EvaporativeEmissions...........................................................25

E. “Well-to-Wheel”GreenhouseGases ...............................................26

VIII.InfrastructureImpacts ..............................................................29A. Distribution. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29

B. Storage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30

C. ServiceStations.................................................................30

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IX. MethanolUseinDieselHeavy-DutyVehicles...........................................33A. UseofMethanolinBlendswithDieselFuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33

B. UseofMethanolinEmulsionswithDieselFuel .....................................33

C. UseofMethanolthroughFumigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34

D. UseofMethanolinDualInjectionEngines.........................................34

E. UseofMethanolwithIgnitionImprovers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34

F. UseofMethanolinDieselEnginesusingCompressionIgnition.......................35

X. Non-RoadEnginesandVehicles. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36A. SmallEngines ..................................................................36

B. LargeEngines ..................................................................36

AppendixA.PropertiesandCharacteristicsofImportanceforFuelSpecifications. . . . . . . . . . . . . . .38A. PropertiesofConcernforLowLevelMethanolBlends ...............................38

B. PropertiesofConcernforHighLevelMethanolFuels(e.g.,M85)......................41

References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42

I. exeCUTIve sUMMaRyNovember 2007


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I. Executive Summary

Thecapabilityofmethanoltoreplacepetroleumfuelshasbeenknownforalongtime.Nowasthefutureavailabilityofcrudeoilisincreasinglycalledintoquestion,methanolisreceivingrenewedinterestsinceitcanbereadilymadefromremotenaturalgasandfromtheworld’sextensivecoalandbiomassresources.Muchworkwasdonepreviouslyaroundtheworldtoidentifytheproperwaystodesignandmodifyvehiclestousemethanoleitherasaneatfuelorinblendswithgasoline.Extensivefleettestswerealsoconducted,withthemajorityoccurringintheU.S.wheremethanolvehiclesweresoldcommerciallyintheearly1990s.Thisreportpresentsseveralsignificantfindingsfromthatworkandexperience.

Methanolhasalonghistoryofuseinracingvehicleswhereitisvaluedbothforitspowerproducingpropertiesanditssafetyaspects(methanolishardertoignite,createslessradiantheat,andburnswithoutproducingblacksmoke).Methanoluseinnon-racingvehicleshasbeenmuchlesssuccessful.TherewassignificantinterestinusingmethanolasagasolineblendingcomponentforitsoctanevalueandemissionscharacteristicsintheU.S.whenleadwasphasedoutofgasolineandmorestringentemissionstandardswereestablished.Severalmethanol/cosolventblendswereapprovedforusebuttheoxygenatemethyltertiarybutylether(whichusedmethanolinitsmanufacture)waspreferred.Duringthe1980sandthroughmuchofthe1990s,mostgasolineinWesternEuropecontainedasmallpercentofmethanol,usually2-3%,alongwithacosolventalcohol.GasolinesusedinEuropeanUnioncountriesareallowedtohave3%methanol,butitisbeingchallengedbyethanol(allowedupto5%nowwithaproposaltogoupto10%)whichisvaluedforitslowgreenhousegases.Today,Chinaistheleaderinusingmethanolasatransportationfuelwherebetween3and5milliontonswereusedlastyear.

Usingmethanolasagasolineblendingcomponentrepresentsthemostexpeditiouswaytouselargeamountsofmethanolasatransportationfuel.Methanoladditionincreasesoctanevalueandwillcausedecreasesinhydrocarbon,toxic,andcarbonmonoxideemissions.Mostmodernfuelsystemswithfeedbackcontrolshouldbeabletoaccommodatelow-levelmethanolblends(upto10%)withoutdifficulty,thoughexceptionsarepossible.Usinglow-levelmethanolblendsdoesrequiregoodhouse-keepingpracticesintransport,storage,anddispensing,toassurethatwateradditionisminimizedtopreventphaseseparation.Addingmethanoltogasolineincreasesvaporpressurewhichcouldleadtoincreasesinevaporativeemissionsduringwarmweather.Additionofacosolvent(typicallyhigheralcohols)amelioratesboththeseissuesandadjustmentofthegasolinespecificationscaneliminatetheincreaseinvaporpressure.Carefultailoringofthegasolineusedtomakemethanolblendscanmaximizethebenefitsofmethanoladditionandincreasegasolinerefiningefficiency.

Intheearly1980s,therewasconsiderableinterestinusingmethanolasafuelforbothpetroleumdisplacementandairqualityreasons.Toachievethequickestdisplacementandlargestimpactonairquality,itwasdesiredtousemethanolneatornear-neatasatransportationfuel.IntheU.S.,fleetdemonstrationsofmethanolvehicleswereverysuccessfulgiventhevehicles’lowemissions,20%increaseinpower,and15%increaseinenergyefficiency.However,thedecreaseinvehiclerange(thefueltankcouldnotbeexpandedsufficientlytocounteractthedecreaseinmethanolheatingvalue)andthesparsenumberofmethanolrefuelingfacilitiescausedmethanolvehicledriversgreatanxiety.Thisdirectlyledtothedevelopmentofmethanolflexiblefuelvehicles(FFVs)whichcouldusemethanolorgasolineinthesametankthroughtheuseofanalcoholfuel

November 2007Use of MeTHanol as a TRansPoRTaTIon fUel I. exeCUTIve sUMMaRy

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sensorthatmeasuredthemethanolcontentofthefuelgoingtotheengine.Thisfreeddriversfromworryingaboutrunningoutoffuelwhilethedevelopmentofmethanolinfrastructurecaughtupwithdemand.TheobjectivewastointroducelargenumbersofmethanolFFVs,buildabroadfuelinginfrastructurenetwork,thentransitionbacktodedicatedmethanolvehicles.FFVsperformedthesameorbetterthantheirgasolinecounterpartswiththesamemassemissions,thoughthiswasalsoaplussincemethanolemissionswereshowntobelessreactive.FleettestsofFFVsoccurredaroundtheworldwiththemostintheU.S.FFVspeakedin1997intheU.S.atjustover21,000withapproximately15,000oftheseinCaliforniawhichalsohadover100refuelingstations.

RelativelyfewchangesareneededtoturnavehicleintoamethanolFFV,andtheincrementalcostislessthanthecostofmostoptionalequipmentoncarstoday.ThereisadrawbacktomethanolFFVs–inordertoaccommodategasoline,theenginecannotbemodifiedtoachievethepowergainsandefficiencyimprovementspossiblewhenonlyusingmethanolasafuelexceptthroughtheadditionofamajorchangesuchasvariablecompressionratio.TuningmethanolFFVstofavormethanolovergasolinewillallowsomeofthesebenefitstoberealized.

InparallelwithFFVdevelopmentintheU.S.,wasthedevelopmentofamethanolfuelspecificationwhatwouldallowvehiclestoachievecold-startandimprovethevisibilityofmethanolflames.Theendresultwasablendof85%methanolwith15%gasolineknownasM85.TheASTMintheU.S.maintainsthespecificationforM85whichhasbeenrecentlyupdated(2007).

Thephysicalandchemicalpropertiesofmethanolmakeitverywell-suitedforuseasaspark-ignitionenginefuel,butitsabilitytocombustwithoutformingsoot(duetothelackofcarbon-to-carbonbonds)hasattracteddieselenginedesignerstofindwaysofusingitaswell.Manywaysofusingmethanolindieselengineshavebeenresearchedincludinguseinblends,emulsions,fumigation,withtheadditionofignitionimprovers,indualinjectionengines,andinenginesmodifiedtoachievedirectcompressionignitionofmethanol.Notethatofthesemethods,onlyuseofignitionimproversandcompressionignitionresultedinenginesthatdisplacedalldieselfueluse,thoughcompletedisplacementwasnotviewedasarequirementsincetheemissionsbenefitsofmethanolweretypicallygreaterthanthepercentdieselfuelitreplaced.Dieselenginescouldalsobeconvertedtosparkignition,butthischangeessentiallymakesthemOttoCycleengines.Lookingforward,homogeneouschargecompressionignition(HCCI)systemsoffertheopportunitytodesignbothheavy-dutyandlight-dutyenginesforcompressionignitionofmethanolandmethanol/dimethyletherblendswithverylowemissionsandhighefficiency.

Thetechnologyforbulkstorageofmethanoliswell-established.Methanolfuelscanbeaccommodatedatretailservicestationsassumingthepropertank,piping,anddispenserisused.Newdry-break,spill-freedispensingnozzlesalleviatesafetyandhumancontactconcernsaboutrefillingmethanolvehicles.

Greenhousegases(GHGs)frommethanolmadefromcoalwillincreaserelativetousinggasolineunlesscarbondioxidesequestrationisimplemented.MethanolmadefromnaturalgaswillhavesimilarGHGsasgasoline.MethanolmadefrombiomassshouldhavesignificantlylowerGHGs.

II. InTRodUCTIonNovember 2007


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II. Introduction

Thecapabilityofmethanoltoreplacepetroleumfuelshasbeenknownforalongtime.Theeasewithwhichcrudeoilcanbeextractedandmadeintofuelhaslongmadepetroleum-basedgasolineanddieselfuelthepreferredchoicesfortransportationvehicles.Nowthatthefutureavailabilityofcrudeoilisinquestion,methanolisreceivingrenewedinterestsinceitcanbereadilymadefromremotenaturalgas,numerousbiomassresources,andfromtheworld’sextensivecoalresources.Methanolisanexcellentfuelforinternalcombustionvehicles,andfuelcellvehiclesusingeitherprotonexchangemembranefuelcellsthatoperateonhydrogenordirectmethanolfuelcells.

Likehydrogen,methanolcanalsobeusedasanenergycarrierwiththeadvantageofbeingaliquidfuelwithhighenergydensityandprovensafety.AsenvisionedintheMethanolEconomy®,methanolismadefromcarbondioxideviacatalyticreductionwithhydrogenorbyelectrochemicalreductionwithwater[1].Thecarbondioxidewouldinitiallycomedirectlyfromfossil-fuelpowerplantsandchemicalplantsandeventuallyfromtheatmosphereitself.Methanolproducedefficientlyfromatmosphericcarbondioxideandhydrogenfromwatercanprovideenergyforfueluseandcouldbetherawmaterialfromwhichsynthetichydrocarbonsandchemicalsaremade.

Methanolhasalonghistoryofuseinracingvehicleswhereitisvaluedbothforitspowerproducingpropertiesanditssafetyaspectsrelativetogasoline:itishardertoignite,itburnsmoreslowly,itemitsnoblacksmokeandemitslowerradiantenergy,whichmakessurroundingmaterialslesslikelytocatchfire.InterestinusingmethanolasablendingcomponentintheU.S.wasintensewhentheoctaneenhancerleadwaslegislatedoutofexistence.ItreceivedadditionalinterestwithpassageoftheCleanAirActAmendmentsof1990,whichenvisagedvehiclesdesignedtorunonmethanol,eitherneatorasM85(ablendof85%methanolwith15%gasoline),tomeetvariousspecialprogramsforalternativefuelvehicles.TheautomakerswereverysuccessfulatengineeringvehiclestouseM85.Thesevehiclesperformedthesameorbetterthantheirgasolinecounterpartswiththesamemassemissions,thoughthiswasalsoaplussincemethanolemissionswereshowntobelessreactive.FleettestsofM85vehiclesoccurredaroundtheworldwiththemostintheU.S.M85vehiclespeakedin1997intheU.S.atjustover21,000[2]withapproximately15,000oftheseinCaliforniawhichalsohadover100refuelingstations.ButautomakersandrefinersquicklyshowedthattheycouldmeettheseemissionstandardswithreformulatedgasolineandstatesconvincedtheU.S.EnvironmentalProtectionAgency(EPA)toletthemopt-outofthealternativefuelvehicleprograms.Inaddition,bythemid-1990s,competitionfromotheralternativefuels,notablyethanolandnaturalgas,dampenedsomeoftheimpetustoimplementmethanol.EthanolrepresentedthegreatestcompetitorsincethesametechnologytomakeM85vehiclesworkedequallywelltomakevehiclesusing85%ethanol(E85).Ethanol’staxcredit,longhistoryofuseinblends,andstronglobbyingsupportfromagriculturalinterestseventuallydisplacedM85intheU.S.Today,thereareover4millionE85vehiclesintheU.S.,thoughonlyabout150,000ofthemuseE85regularly[2].TheonlyroleformethanolcurrentlyasatransportationfuelintheU.S.isasacomponenttomakebiodiesel,whereitisreactedtoformmethylesters.Chinaiscurrentlythelargestuserofmethanolfortransportationvehiclesintheworld.

Interestisagainhightousemethanolasatransportationfuel,particularlyinregionsoftheworldwherethereisanabundanceofreadilyavailablefeedstocks(coal,naturalgas,biomass)fromwhichmethanolcanbeproduced.Muchworkwasdoneinmanycountriespreviouslytoidentifytheproperwaystomodifyvehiclestousemethanoleitherasaneatfuelorinblendswithgasoline.Thisreportpresentsmanyofthemostsignificantfindingsfromthatwork.

November 2007Use of MeTHanol as a TRansPoRTaTIon fUel III. MeTHanol blend RegUlaTIon

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III. Methanol Blend Regulation

Whileithaslongbeenknownbyenginedesignersthatmethanolcouldbeusedasaninternalcombustionenginefuel,itwasnotuntilemissionsandoildependencyconcernswereraisedintheUnitedStatesthatmethanolwasrecognizedmorewidelyasapotentialtransportationvehiclefuel.In1970,RobertaNicholsandco-workersattheAerospaceCorporationpublishedareportidentifyingtheemissionsbenefitsofmethanolasatransportationfuel[3].Laterin1970,amethanol-fueledvehiclewasenteredbyHenryAdelmanofStanfordintheCleanAirCarRace.Hisvehicle(anAMCGremlin)placedfirstintheliquidfuelclassforoverallperformancewhilemeetingthe1975emissionstandards,despiteveryfewenginemodifications.Thisdemonstrationofthecapabilitiesofmethanolpiquedinterestinitsuse.Then,in1971,theEPAannouncedaproposedrule-makingtophaseoutuseofleadingasoline.Thisgaveinterestinmethanolanotherboostbecauseofmethanol’shighoctanerating.TheEPAfollowedtheinterestinmethanolcloselyandin1973commissionedbothExxon(nowExxonMobil)andtheInstituteofGasTechnology(nowtheGasTechnologyInstitute)toconductresource-through-end-usestudiesofalternativefuelstopetroleumforhighwaytransportation.Bothofthesestudiesratedmethanolveryhighlyforitsabilitytouseexistinginfrastructure,foritsnon-petroleumresourcebase,foritslowemissions,andbecauseitcouldbeusedininternalcombustionengineswithoutdrasticmodifications.Theninthefallof1973,theAraboilembargoofcrudeoilsalestotheU.S.greatlyescalatedtheinterestinalternativefuels,ofwhichmethanolwasprominent.FollowingisthehistoryandstatusofmethanolregulationasafuelintheU.S.andEurope.

A. United StAteS

TheCleanAirActamendmentsof1977includedthecreationofsection211(f),whichprohibitstheintroductionintocommerceofanyfuelorfueladditivethatisnotsubstantiallysimilartofuelsusedinvehiclecertification.TheEPAmayissueawaiveroftheprohibitionifapartydemonstratesthatthefuel/additivewillnotcauseorcontributetothefailureofanyemissionscontroldeviceorsystem.

1. EPA WAIVERS GRANTED AND OxyGENATE ALLOWANCES AS “SUBSTANTIALLy SIMILAR”

ThefirstwaiverrequestforanoxygenatedcompoundreceivedbyEPAwassubmittedbyGasPlusandtheIllinoisDepartmentofAgricultureinJune1978for“Gasohol”,ablendof90%gasolineand10%ethanol.Thewaiverapplicationcontainednoactualdataonethanol/gasolineblends.Instead,itincludeddataonmethanol/cosolventblendsandonmethyltertiarybutylether(MTBE),whichwasarguedtoshowexpectedemissionsimpactsfromethanolaswell.TherewasalsoareferencetosomeemissionstestsconductedbythestateofNebraskaon26vehicles,apparentlywithgasoline/ethanolblends,whichwerenotidentifiedandnodataweregiven,butastatementsaidthatthetestsshowedhigherNOxandsomewhatlowerCOandHCemissions[4].

Becauseofthelackofdata,EPAwasunabletograntthewaiverapplication.ButEPAalsodeclinedtodenythewaiverapplicationand,underthetermsofsec.211(f)(4),applicationsaredeemedgrantedafter180daysiftheyhavenotyetbeendenied.OnApril6,1979,EPAissuedaFederalRegisternoticeconfirmingthattheapplicationhadbeendeemedgrantedbyexpirationofthe180-dayperiod[5].

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TheGasoholwaiverapplicationincludednospecificationsdefininguseofthewaiver.BecauseEPAissuednonoticegrantingthewaiver,italsofailedtoimposeanyspecifications.ThisledtoaneedtosubsequentlyissueinterpretationofthewaiverinApril1982clarifyingthatblendsoflessthan10%couldalsobeused[6].Althoughitisnotspecifiedanywhere,EPAhasalsointerpretedthesepercentagelimitstoapplybyvolumeratherthanbyweightormole.

The10%limitonethanolwasgenerallybelievedtotranslatetoapproximately3.5-3.7%oxygeninthegasolinebyweightbasedonsampleanalysis.

In1979,EPAissuedwaiversforupto7%tertiarybutylalcohol(TBA)[7],forupto7%MTBE[8],andforupto5.5%ofacombinationofmethanolwithTBAinequalparts[9].Thesewaiversallowedabout2%oxygenbyweightinthefuelblend.

InOctober1980EPApromulgateditsfirstrealInterpretiveRuledefiningwhatfuelsandadditiveswereconsideredsubstantiallysimilartocertificationfuels[10].(Priortothis,itconsideredonlythoseidenticaltofuelsandadditivesusedincertificationtobe“substantiallysimilar”or“sub-sim.”)Ittreatedaliphaticethersandalcoholsotherthanmethanolassub-siminvolumescontributing2%orlessoxygenbyweight.

InJuly1981,EPAissuedarevisedInterpretiveRulefurtherdefining“sub-sim.”Itallowedforuseofupto2.75%methanolwithanequalvolumeofTBA(orhigheralcohols),aspreviouslyprovidedbywaiver,essentiallyconfirmingthatallowancesmadeinwaiversareapplicabletoallmarketers,notmerelytheapplicant[11].EPAwasaskedinthisrulemakingtoincreasetheoxygenlimitto3.7%,equivalenttothatofGasohol,butEPAdeclinedtodosobasedonobservedNOxincreases,keepingthesub-simoxygenlimitat2%[12].

InNovember1981,EPAgrantedawaiverforuseofARCO’s“Oxinol,”allowingupto4.75%methanolwithanequalamountofTBA,whichprovidesapproximately3.5-3.7%oxygen[13].Thisoxygenlevelbecametheeffectivelimitthereafter.EPAgrantedwaiverstoDupontCorporation(1985)[14]andTexasMethanolCorporation(1988)[15]allowingmethanol/cosolventcombinationsupto3.7%oxygenandincludingethanolasacosolventalcohol,inadditiontohigheralcoholsalreadyallowed.

EPAalsograntedawaiverforupto15%MTBEin1988,whichprovidesapproximately2.7%oxygen[16].Thiswaiverwasrequestedandgrantedatlessthantheoxygenlimitallowedforalcoholsbecauseofthehighvolumeoftheoxygenateitself.Becauseoxygenateshavevariousproperties,distillationimpacts,etc.thataresignificantlydifferentfromgasolinehydrocarbons,15%wasseenastheacceptablelimitforoxygenates,independentoftheoxygencontribution.

In1991,onapetitionfromtheOxygenatedFuelsAssociation,EPArevisedtheInterpretiveRuleonsub-simtoallowformixturesofMTBE(orETBE)andaliphaticalcoholsotherthanmethanoluptothe2.7%oxygenlimitingasoline[17].(Thiscorrespondstothe15%MTBElimit.The2.7%oxygenfromETBEwouldallowabout19%ETBEbutitwasnotexpectedthatthishighcostoxygenatewouldbeusedatsuchalevel.)

InworkshopsrelatingtoimplementationofthefederalReformulatedGasoline(RFG)programestablishedbytheCleanAirActAmendmentsof1990,EPAwasinformedthatwiththe(lowerdensity)fuelsanticipatedasRFG,10%ethanolwouldprovideapproximately4%oxygenbyweight,whereasEPA’smodelonlyextendedupto3.7%oxygen.EPAconfirmedthatuseof10%ethanol


6

wouldbeallowedinRFGevenwiththeoxygenatsomewhatabove3.7%(nooxygenlimithavingbeenestablishedfor10%ethanolblends).

Itshouldbenotedthatthemethanolblendwaiversapprovedremainineffecttoday,thoughthepromulgationofadditionalregulatoryrequirementsforgasolineadditivesmeansthatsomeadditionaltestingwouldbeneededbeforetheycouldbemarketedbylargecompanies.

2. EPA DENIALS/REVOCATIONS OF WAIVERS AT HIGH ALCOHOL/OxyGEN LEVELS

InMarch1980,EPAdeniedawaiverapplicationfromBekerIndustriesforupto15%methanol[18].Thedenialwasbasedlargelyontheabsenceofadequatedata.(Infact,nodatahadbeensubmittedonmethanolwithoutcosolventadditives.)ButEPAalsonotedthatthedatasubmittedathighalcohollevelssuggestedthattherecouldbeproblems,includingincreasesinemissionsanddeteriorateddriveability,resultingfromthehigheroxygenlevels.

InAugust1980,EPAdeniedawaiverapplicationfromConservationConsultantsofNewEnglandfor5%ethanolwith5%methanol(oxygencontent4.4%)[19].Theapplicationhadalsorequestedwaiversfor(1)10%methanolwith5%ethanoland(2)8%methanolwith2%ethanol,buttheserequestshadbeenwithdrawnbytheapplicant[20].Thedenialwasbasedonabsenceofdata,butEPAnotedproblemsanticipatedwithexhaustemissions,evaporativeemissions,driveability,andmaterialscompatibility.

InOctober1981,EPAgrantedawaivertoAnafuelUnlimitedforamixtureofupto12%methanolwith6%butanolsandaproprietaryinhibitor[21].Thewaiverwasgrantedunderextremeduress–pressurefromtheWhiteHouseandsomesenators.Thiswouldhaveprovidedaround7%oxygeninthefuel.Subsequenttesting,however,showedthatthetestdatasubmitteddidnotreflectthealcoholpackageinthatvolumeandtheMotorVehicleManufacturers’Association(MVMA)filedbothacourtchallengeandapetitionforEPAreconsideration.EPAproposedtorevokethewaiverbyreconsideration(1984)[22]buttheD.C.CircuitCourtruledthatwaiverswerenotsubjecttosuchreconsiderationbeyonda30dayperiodprovidedinsec.211(f)(4)[23].TheD.C.CircuitCourtsubsequentlyruledinfavorofMVMA’ssuit,however,vacatingtheoriginalgrantingofthewaiversuchthatEPA’sevaluationofitwouldresumewithoutthetainteddata[24].EPAdeniedandfinallyrevokedthewaiverin1986[25].Inthemeantime,AmericanMethylCorp.,successortoAnafuel,hadappliedforanotherwaiverwithavariationoftheformulaata5%oxygenlevel.EPAdeniedthatrequestinNovember1983[26].

In1987,inessentiallythesametimeperiodthattheTexasMethanolCorporation’swaiverapplicationwaspending,EPAwasaskedbyAMLaboratories,Inc.tograntawaiverforuseofupto5%methanolwith5%ethanol,foranoxygencontributionof4.4%,similartothatwhichithaddeniedin1981toConservationConsultants.TheapplicationattachedareportofamajorCanadiantestprogramthatincludedsuch5%/5%blendsandinwhichthedriveabilitydemeritswerearguednottobeexcessive.Theautomakersfiercelyopposedtheapplication,arguingthatotherexistingdataclearlyshoweddriveabilitytobedegradedunacceptablyatlevelsabovearound3.7%.Forthefirsttime,oppositionwasnotlimitedtoU.S.automakersbutincludedopposingsubmissionsfromToyota,aswell.InJanuary1988,EPAissueditsFederalRegisternoticeanddecisiondocumentdenyingthewaiver[27].

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3. USE OF METHANOL IN U.S. FUELS

Inthemid-1980sARCOundertooktheonlyseriouseffortatmarketingmethanolblendsintheU.S.,usingitsOxinolmixtureofmethanolandTBA.ItusedtheOxinolinsomeofitsowngasolineandalsomarketedittoindependentrefinersandblenders.ManyofthoseindependentcustomerssubsequentlydiscontinuedpurchaseoftheOxinol,however,citingreportsfromcustomersofphaseseparationand/ordamagetoelastomersandotherrealorperceivedproblems.ARCOdiscontinueditsmarketingofOxinolsometimearound1986.EPA’sfinalregulationonfuelvolatilityinMarchof1989,whichallowedaonepsidifferentialforethanolblendsbutnotformethanol/cosolventblends,putthemethanolblendsatanadditionalmajordisadvantageandprobablyrepresentedtheirdeath-knellintheU.S.EPA’sRFGandconventionalgasolineanti-dumpingprogram,basedonmodelswhichfavoredevenlowervolatility,madethisbarrierevengreater.Inaddition,EPA’sComplexModelforRFG,useofwhichbecamemandatoryasofJanuary1,1998,didnotincludeparametersrepresentingblendingofmethanoleitherforvolatileorganiccompoundreductioncreditorforcalculationofaldehydeemissionstomeetthetoxicsemissionsstandards.Inorderformethanol/cosolventblendstobeusedinRFG,themodelwouldhavetobe“augmented,”whichwouldrequiresubstantialandexpensiveemissionstestingwithawidevarietyoffuelblendsandvehicles.

Whilethemethanol/cosolventblendsfailedtocatchonintheU.S.,theuseofMTBEprovidedapathformethanoltobeusedingasoline.Bythelate1980s,MTBEproductionhadsurpassedformaldehydeproductionasthegreatestsingleuseofmethanolworldwide.PassageoftheCleanAirActAmendmentsof1990,withtheRFGprogramandtheOxyfuelsprogram,gavefurtherbooststoMTBE.TheRFGprogramrequired2.0%oxygeninRFGduringwarmweathermonthsinthemostseriousozonenon-attainmentareas,whiletheOxyfuelsprogramrequired2.7%oxygeninmanycarbonmonoxide(CO)nonattainmentareasduringcoldmonths.MTBEbecametheoxygenateofchoiceinRFGandwasalsousedtosomeextentinOxyfuelsregions.Astheseprogramswerebeingimplemented,demandformethanoloutstrippedsupplyintheU.S.bysomuchthatmethanolpricesreachedlevelsof$1.85/gallon.

TheCleanAirActAmendmentsof1990envisagedthattherewouldbeamovetowardvehiclesdesignedtorunonmethanol,eitherneatorasM85,tomeetvariousspecialprogramsforalternativefuelvehicles(AFVs),includingtheCleanFuelFleet(CFF)ProgramandtheCaliforniaPilotTestProgram[28].ButautomakersandrefinersquicklyshowedthattheycouldmeettheemissionstandardswithRFGandstates,havingdeterminedthatsuchprogramswerenotcost-effectivewaysofreducingpollutants,convincedEPAtoletthemoptoutoftheCFFprogram.FrustratedwiththelackofprogressinuseofAFVs,CongressenactedlimitedfleetAFVacquisitionrequirementsintheEnergyPolicyActof1992(EPAct92),whichalsocontemplatedmethanolvehicleuse.ButinitialimplementationofthisprogramcoincidedwiththerunawaymethanoldemandforMTBEusewithintheRFGprogramandassociatedrunawaypricessomethanolvehicleswerelargelyignoredintheseAFVprogramsthathadbeendesignedwiththeminmind.

Byearlyinthisdecade,detectionofMTBEingroundwaterinvariouslocationsraisedconcernsthatledanumberofstatestobanuseofMTBE,anditsusefelloffsharplyasaresult,largelythroughsubstitutionofethanol.Then,theEnergyPolicyActof2005(EPAct05)eliminatedtheoxygenrequirementforRFGwhileimposinga“RenewableFuelStandard,”essentiallyarequirementforuseofincreasingvolumesofethanolbyrefiners.AbsenttheRFGoxygenrequirement,refiners’concernsaboutliabilityforleaksofMTBEhavepromptedallmajorU.S.refinerstoceaseblendingofMTBEandithasvirtuallydisappearedfromU.S.gasolinesupplysinceMay2006.


8

WiththeeliminationofMTBE,theonlysignificantuseofmethanolinU.S.fuelsupplyisitsuseinproductionofmethylesterbiodiesel.AlthoughthisaccountsforalmostallU.S.biodiesel,dieseluseintheU.S.isfarlowerthangasolineuseandonlyasmallpartofU.S.dieselfuelincludesbiodiesel,mostlyatthe20%blendlevelorless.Therefore,thebiodieselusedoesnotcompensateforthelossofMTBEasasourceofmethanoldemand.

B. USe of MethAnol BlendS in the eUropeAn Union

MethanolfuelblendswereintroducedintheFederalRepublicofGermanyin1968withuseof2%methanol/2%TBAblends,reachinggeneralusearound1977.TheGermangovernmentsetalimitof3%methanol.Duringthe1980sandthroughmuchofthe1990s,mostgasolineinEuropecontainedasmallpercentofmethanol,usually2-3%,alongwithacosolventalcohol.A“commondirective”oftheEuropeanEconomicCommunity(EEC,apredecessortotheEuropeanUnion-EU)authorizedalcoholblendingingasolinestartingin1988,includingalowlevelthatmembercountrieswererequiredtoallowandahigherlevelthatcouldbeallowedbymembercountrieswithlabelingonpumps.Franceauthorizedsuchhigherlevelblends,buttheiruseapparentlydidnotbecomewidespread.InSweden,whereoxygenateswereallowedupto3wt%oxygen,methanolwasalsoallowedupto2%[29].ThecurrentEUstandard,EN228,aslastrevisedin2004,allowsupto3%methanoltobeused,witharequirementforacosolvent(“stabilizingagent”).InJanuaryof2007,theEuropeanCommissionproposedanewfuelstandardthatwouldrequireallfuelsmarketedinEuropetomeetastandardforgreenhousegasemissions,whichwouldincludeareductioningreenhousegas(GHG)emissionsby1%peryearfrom2011through2020,withtheintentthatthesereductionsbemetlargelythroughincreasingthebiofuelscontentofthefuel.Theproposalstatesthatanewgasolinestandardwillbepromulgatedthatwillallowupto10%ethanoltoaccommodatetheGHGemissionsreductions,comparedtothecurrentstandardthatallowsonly5%ethanol.

Iv. MeTHanol Use In flexIble fUel veHIClesNovember 2007


9

IV. Methanol Use in Flexible Fuel Vehicles

Intheearly1980s,therewasconsiderableinterestinusingmethanolasafuelforbothpetroleumdisplacementandairqualityreasons.Toachievethequickestdisplacementandlargestimpactonairquality,itwasdesiredtousemethanolneatornear-neatasatransportationfuel.ForddevelopedaversionoftheirEscortin1981thatranon90%methanolanda10%hydrocarbonblendspecificallytailoredtogivereliablecoldstarts[30].FortyofthesemethanolEscortswereputintofleetuseinLosAngelesandtheir20%increaseinpowerand15%increaseinenergyefficiencymadethemverypopularincomparisontothegasolineversions.TheseinitialvehiclesweresosuccessfulthatLosAngelesaskedformoreandin1983Forddeliveredanadditional501.However,therefuelinginfrastructurewasnotexpandedsufficientlyandthedecreaseddrivingrange(approximately230milesversus300forgasoline)becameanissue.Thisexperiencedirectlyledtothedevelopmentofmethanolflexiblefuelvehicles(FFVs)whichcouldusemethanolorgasolineinthesametankthroughtheuseofanalcoholfuelsensorthatmeasuredthemethanolcontentofthefuelgoingtotheengineandadjustedthefuelflowrateandsparkadvanceaccordingly.Thisfreeddriversfromworryingaboutrunningoutoffuelwhilethedevelopmentofmethanolinfrastructurecaughtupwithdemand.TheobjectivewastointroducelargenumbersofmethanolFFVs,buildabroadfuelinginfrastructurenetwork,thentransitionbacktodedicatedmethanolvehicles.FigureIV.1showsthedifferencesinamethanolFFVfromthestandardgasolineversionfromwhichitwasderived.

AsFigureIV.1shows,relativelyfewchangesareneededtoturnavehicleintoanFFV.Analcoholfuelsensorisusedtomonitorthefuelmixtureandsignaltheon-boardcomputertoadjustfuelflowandsparktiming(currentmodelethanolFFVshaveeliminatedthesensor–performingthattaskwithsoftware).Largerfuelinjectorsareusedtocompensateforthemethanol’slowerenergycontenttoassurethatthesameamountofmaximumenginepowerisproduced.

fIgURe Iv.1 Changes in FFvs Compared to Straight Gasoline models

1996 TAURUS 3.0L FFV

November 2007Use of MeTHanol as a TRansPoRTaTIon fUel Iv. MeTHanol Use In flexIble fUel veHICles

10

Becausemethanoliscorrosiveandwillattackcertainmetals(suchasaluminumandmagnesium)andelastomers(includingrubberandpolyurethane),electrolessnickelplatedorstainlesssteelfueltanksandstainlesssteelorTeflon®-linedfuellinesareemployed,andmethanol-compatibleelastomersareusedinallfuel-wettedparts.Ananti-siphondeviceisinstalledinthefillerneckandanenlargedcarboncanisterisinstalledtocontainevaporativeemissionswhenco-minglingoccursinthefueltank,i.e.,whenthefuelinthetankcontains5-20%methanolwiththeremaindergasoline.

Therewasacompromise,however,inthemethanolFFVs–inordertoaccommodategasoline,theenginewasnotmodifiedtoachievethepowergainsandefficiencyimprovementsdemonstratedbyFordintheirfirstmethanolEscorts.Nonetheless,FFVswereperceivedasthe“missinglink”inthetransitiontomethanol.

WhenFFVswerefirstsold,theincrementalretailpricewasaround$350.ThemanufacturersneverrevealedtheincrementalcostofmakingFFVsnorfullydefinedwhatchangestheymade.Today,aftermillionsofethanolFFVshavebeensold,thesituationhasnotchanged,butestimatesoftheincrementalcostarenowbetween$50-100.MethanolFFVsbuiltinlargevolumewouldbeexpectedtohaveasimilarincrementalcost,thoughperhapsslightlyhigherifmoreexpensivefuelsystemmaterialsarerequiredrelativetoethanol,andwhethermethanolFFVscandowithoutafuelsensorasethanolFFVshavelearnedtodo.

InparallelwithFFVdevelopment,wasdevelopmentofamethanolfuelspecificationwhatwouldallowvehiclestoachievecold-startandimprovethevisibilityofmethanolflames.Theendresultwasablendof85%methanolwith15%gasolineknownasM85.WhileFordshowedonly10%hydrocarbonswereneeded,theextra5%allowedtypicalspecificationgasolinetobeusedwhichwasabundant,ofcourse,butmoreimportantly,inexpensive.

In1988,theCaliforniaEnergyCommissionestablishedtheCaliforniaFuelMethanolReservetoincreasetheavailabilityofmethanolfuelacrossthestate.Theagencyalsoenteredintovoluntary10-yearleaseagreementswithARCO,Chevron,Exxon,Mobil,ShellandTexacofortheinstallationofmethanolundergroundstoragetanksandfuelingpumpsat60publicretailstations.Thestateandlocalagencieswouldhelpbuildanother45privatefleetaccessiblefuelingstationsacrossthestate.Fromthemid-1980stothelate1990s,over15,000methanolFFVswereoperatingonCalifornia’sstreetsandfreeways,alongwithhundredsofmethanol-fueledtransitandschoolbuses.Attheheightoftheprogramin1993,over12milliongallonsofmethanolwasusedasatransportationfuelinthestate.

WhilemostautomakersbuiltanddemonstratedFFVs,onlyfourmethanolFFVmodelsmovedfromprototypedemonstrationstocommercialavailability.TheyweretheFordTaurusFFV(1993-1998modelyears);ChryslerDodgeSpirit/PlymouthAcclaim(1993-1994modelyears);ChryslerConcorde/Intrepid(1994-1995);andtheGeneralMotorsLumina(1991-1993modelyears).Thesemid-sizedsedanswerethelargestsellingfleetvehiclesonthemarket,andfleetsarewherethevastmajorityofmethanolFFVsweresold.Bythe1996modelyear,theFordTaurusFFVwastheonlymethanol-fueledvehicleonthemarket,andittoowouldbediscontinuedafterthe1998modelyear.Bythistimemanyoftheoriginal10-yearleaseagreementswiththemajoroilcompaniestooperatemethanolpumpsattheirretailstationshadexpired,andthemethanolpumpslargelyturnedovertopumpinggasoline.

Iv. MeTHanol Use In flexIble fUel veHIClesNovember 2007


11

Californiawasnottheonlystatetodemonstratetheuseofmethanol-fueledvehicles.Methanolfuelingstationswerebuiltin15statesbetweenthemid-1980sandmid-1990s.TheNewYorkStateThruwayAuthorityfundedtheinstallationofabove-groundmethanolstationsatrestareasalongtheentirestate-widerouteoftheNewYorkThruway,fromtheTappanZeeBridgetoNiagaraFallstoserveafleetofmethanolFFVs.

Fromthesedemonstrationefforts,itwaslearnedthattherearenotechnicalbarrierstobuildingmethanol-fueledvehicles.Itwasalsolearnedthatmethanolcanbeeasily,safelyandeconomicallystoredanddispensed.Thecosttoinstallamethanolfueledundergroundstoragetankanddispenserisaround$60,000andmostinstallationscanbecompletedin60days.ImplementationofmethanolFFVsandmethanolinfrastructurecouldproceedrapidly,especiallyconsideringtheexperiencegainedwithethanolFFVsandtheethanolinfrastructure.

November 2007Use of MeTHanol as a TRansPoRTaTIon fUel v. MeTHanol blend PHysICal and CHeMICal PRoPeRTy IMPaCTs

12

V. Methanol Blend Physical and Chemical Property Impacts

Addingmethanoltogasolinecausesbothphysicalandchemicalpropertychanges,primarilyanincreaseinvaporpressureandchangeddistillationandmaterialscompatibilitycharacteristics.Thesechangesinphysicalandchemicalpropertiescanhaveadverseeffectsonvehicleoperationandemissions.Thissectionlooksatthesechangesandidentifiessomewaysthechangescanbemanaged.

A. VApor preSSUre

WhiletheReid1vaporpressure(RVP)ofmethanolisonly4.6psi(32kPa),comparedtogasolinethatistypicallyintherangeof7-9psi(48-63kPa),addingmethanoltogasolinecausesanincreaseinvaporpressure.Thisisbecausemethanolcombineswithcertainlowmolecularweighthydrocarbonstoformazeotropes.Azeotropeshavelowerboilingpointsthanthehydrocarbonsfromwhichtheyaremade,resultinginanincreaseinvaporgenerationatlowertemperatures.FigureV.1illustratesthisphenomenonwhichhasbeendocumentedwidelybyseveralresearchers[31,32]

FigureV.1showsthattheeffectofmethanolongasolinevaporpressurepeakswithadditionofaround10%methanolbyvolume,anddecreaseswithlargeradditions,decreasinginanalmostlinearfashionto4.6psiat100%methanol.(However,theincreaseinvaporpressurevariesslightly

1ReidvaporpressurereferstoaspecificASTMtest(D323)conductedat100°F.

Volume % oxygenate in gasoline

Ble

nd R

VP, p

si

0 5 10 15 20

13

12

11

10

9

8

Methanol/TBA(1:1)

Ethanol

Methanol

MTBETBA

fIgURe v.1 The effect of Alcohol Addition to Gasoline rvP (Source: ref. 32)

v. MeTHanol blend PHysICal and CHeMICal PRoPeRTy IMPaCTsNovember 2007


13

witheachblendofgasoline.)WhatisparticularlysignificantwhenaddingmethanoltogasolineistheveryrapidriseinRVP–thevastmajorityoftheincreaseoccursbythetime2-3%methanolisadded.ThislargeincreaseinRVPcreatesverylargeincreasesinvaporgenerated,whichoftenoverwhelmthefuelevaporativesystemandresultinsignificantlyincreasedevaporativeemissions.CosolventscanmoderatetheincreaseinvaporpressuresomewhatasillustratedinFigureV.1fora50/50blendofmethanolandTBA,butthemosteffectiveremedyistodecreasetheRVPofthebasegasoline.Whenusedwithcosolvents,theRVPpeakoccursataround5%alcoholcontent.

FigureV.2showstheeffectmethanolandotheralcoholshaveonthedistillationcurveofgasolinewhenaddedatthe15wt%level.Methanol(labeledC1inFigureV.2)showsthelargestdistillationcurvedistortionwhichiscausedbythemethanolanditsazeotropesboilingofffirst.Afterabout60%distilled,almostallthemethanolisvaporizedandthedistillationcurverevertsbacktobenearlythesameasforstraightgasoline.

B. WAter tolerAnce

Whilemethanolissolubleingasoline,thepresenceofwatermaycausephaseseparation(waterandmethanolseparateoutofsolution).Whetherphaseseparationoccursdependsontheamountofwaterandthetemperature–highwatercontentandlowtemperaturesfavorphaseseparation.Methanolistheworstalcoholinregardtophaseseparation,whichisoneofthereasonsthathighermolecularweightalcoholshavebeenfrequentlyrecommendedascosolventsformethanol/gasolineblends.Cosolventsamelioratephaseseparation,vaporpressureincrease,andmaterialscompabilityproblems.TheEPAhasrequiredcosolventsforallmethanolblendwaiversforthesethreereasons.ForhighmethanolcontentfuelssuchasM85,phaseseparationisnotaproblembecauseofthelargecapacityofmethanoltoabsorbwater.

FigureV.3showsthewatertoleranceofagasolinewithvariousconcentrationsofmethanol.Thisfigurevividlyillustrateshowmethanoladditionquicklycausesthetemperatureatwhichphaseseparationoccurstorise.Forexample,10wt%methanolwillseparatewhentheblendiscooledtoatemperatureofonly15°F(-9°C).At15wt%methanolthephaseseparationtemperaturerisestojustbelowfreezing.

0 20 40 60 80 100

500

400

300

200

100

0

No alcoholMethanolEthanoln-Propanoli-Butanol

B.P. - C1

DISTILLATED RECOVERED, volume percent

15% of Various Alcohols in Gasoline

B.P. - C2

B.P. - C3

B.P. - C4

DIS

TILL

ATIO

N T

EMPE

RAT

UR

E, °F

fIgURe v.2 The effect of Alcohol Addition to Gasoline Distillation (Source: ref. 31)


14

Cosolventscanhaveadramaticeffectonthewatertoleranceofgasolineblendedwithmethanol.FigureV.4showstheimpactthatadding5wt%alcoholcosolventscanhaveonthewatertoleranceofa10wt%blendofmethanolingasoline.ThehigheralcoholsofFigureV.4significantlyimprovethewatertoleranceofmethanolblends.

Thecompositionofthegasolinecanalsohavealargeimpactonmethanolsolubility.Gasolineswithhigharomaticcontentwilldissolvemoremethanolthangasolineswithhighparaffiniccontent.TableV.1showsthelargeimpactgasolinecompositioncanhaveonmethanolsolubility.

c. MAteriAlS coMpAtiBility

Automotivefuelsystemscontainawiderangeofelastomeric2andmetalliccomponents.Theelastomersareusedprimarilyassealsandfuellinesbutvehiclemanufacturershaverecentlybeenmovingtofuellinesthatarenon-metallicallthewayfromthefueltanktotheenginefuelsystem,whichgreatlyincreasestheamountofwettedareabetweentheelastomersandthefuel.Manyfueltanksarenownon-metallicaswellforreasonsofcostandabilitytobemoldedintocomplexshapesthatmaximizevolumeintightvehicleconfines.2Elastomerisagenerictermthatincludesallsoftpartsinafuelsystemincludingrubbers,plastics,nylons,fluorosilicones,urethanes,etc.

PHA

SE S

EPA

RAT

ION

TEM

PER

ATU

RE,

°F

0.04 0.08 0.12 0.16 0.20 0.24WATER, weight percent

90

80

70

60

50

40

30

20

10

0

Methanol

30%

20%15%10%5%

3%

CLO

UD

PO

INT

TEM

PER

ATU

RE,

°F

0 .1 .2 .3 .4 .5 .6 .7

WATER, weight percent

80

70

60

50

40

30

20

10

0

-10

-20

Plus

eth

anol

Plus

2 -

prop

anol

Plus

1 -

prop

anol

Base

fuel Pl

us m

etha

nol

Plus

ben

zene

fIgURe v.3 The Water Tolerance of methanol Added to Gasoline (Source: ref. 31)

fIgURe v.4 The Impact of Cosolvents on the Water Tolerance of a 10 wt% blend of methanol in Gasoline (Source: ref. 31)



15

Elastomersmustnotcrack,leak,orbecomepermeabletofuel;iftheydo,vehiclesafetyisimpairedand/orevaporativeemissionsincreaseswilloccur.Noelastomeriscompletelyunaffectedbyexposuretofuel,withchangesoccurringinvolume(swell),tensilestrength,andelongation.Theadditionofmethanoltogasolinecauseschangesinelastomersthataredifficulttopredict.FigureV.5illustratestestingdoneonvariousgenericelastomersusedinfuelsystems(measuringswell)usingtwogasolines,neatethanol,andablendofthebasegasolineand10%methanol[32].Ingeneral,neatmethanolcausedlessswellingoftheelastomersthantheblendof10%methanolingasoline,andinmostcases,the50%aromaticgasolinecausedmoreswellingthan10%methanol.Onlythefluorocarbonshowedmoreswellinginmethanolandthe10%blendthanineitherofthegasolinestested.

Table v.1 methanol Solubility based on Gasoline Composition (Source: ref. 32)

Aromatics in Gasoline, Volume percent

Methanol Solubility, Volume percent

-10° to 0°f 32° to 37°f

16 2-3 5-10

28 5-10 15-20

31 5-10 >50

42 >50 >50

Gasoline composition Minimum temperature at which 10% Methanol

will dissolve, °fSaturates Aromatics olefins

100 - - 80

65 21 14 44

43 2 55 20

20 78 2 4

0

50

100

150

200

250

30% AromaticGasoline (A)

50% AromaticGasoline

Neat Methanol 10% Methanol,90% Gasoline A

Elas

tom

erSw

ell(

%)

FluorocarbonPolyester UrethaneFluorosiliconeButadiene-acrylonitrilePolyacrylateChlorosulfonatedPolyethyleneEthylene-propylene-dieneterpolymerNatural Rubber

fIgURe v.5 elastomer Swell from exposure to Gasoline, methanol, and a 10% methanol blend (Source: ref. 32)


16

FiguresV.6andV.7showadditionaltestdatacomplementarytotheresultsinFigureV.5forpolyesterurethaneandfluorocarbonovertheentirerangeofmethanolblendsfrom0to100%[33].Thesedatashowthatelastomerschangecontinuouslywithpercentmethanolcontent,withthegreatestchangeoftenoccurringwithanintermediateblend.Afieldtrialof4%and15%methanolingasolineinNorwayreportedswellingofsomefuellines,thoughtheamountwasnotquantified[34].InasimilarfieldtrialofM15inNewZealand,problemswithfuellineswereobservedalongwithotherfuelsystemelastomersincludingcarburetorneedlevalveseats,fueltanklevelfloats,andfuelpumpdiaphragms[35].TheproblemsreportedintheNewZealandfleettestwerejudgedtoberelativelyminorandwereeasilycorrectedbyreplacementwithnewparts.Withoutacontrolfleet,itisnotknownwhethertheseproblemsrepresentedasignificantchangeornot.

Thesedatasuggestthattheimpactofmethanolonelastomermaterialsisrelativelybenigncomparedtohigharomaticgasolines.However,thesetestsweredoneusingnewelastomersandrelativelypurefuels.Aselastomersageinservice,theyarelessamenabletochange.Thereareseveralinstancesoffieldproblemscausedbychangesinfuelproperties.Forexample,thechangetoultra-lowsulfurdieselfuelcausednumerousfuelsystemleaksbecausetheelastomerswereadverselyaffectedbyarelativelysmallchangeinfuelproperties.Newversionsofthesameelastomersworked,illustratingtheimpactagingcanhaveonfuelsystemelastomers.Otherconfoundingfactorsinclude

* MPa = Mega-Pascals

Alcohol (vol%)0 10 20 30 40 50 60 70 80 90 100

1109070503010

0-10

Volu

me

Chan

ge (%

) Alcohol (vol%)0 10 20 30 40 50 60 70 80 90 100

16141210

86420

Tens

ile S

treng

th (M

Pa*)

Alcohol (vol%)0 10 20 30 40 50 60 70 80 90 100

200150100

500El

onga

tion

(%)

MethanolEthanol

fIgURe v.7 Fluorocarbon Compatibility with ethanol and methanol blends (Gasoline A from Figure v.5; Source: ref. 33)

* MPa = Mega-PascalsAlcohol (vol%)

0 10 20 30 40 50 60 70 80 90 100

70605040302010

0Volu

me

Cha

nge

(%)

Alcohol (vol%)0 10 20 30 40 50 60 70 80 90 100

2016

8840

Tens

ile S

treng

th (M

Pa*) Alcohol (vol%)

0 10 20 30 40 50 60 70 80 90 100

500400300200100

0Elon

gatio

n (%

)

MethanolEthanol

fIgURe v.6 Polyester Urethane Compatibility with ethanol and methanol blends (Gasoline A from Figure v.5; Source: ref. 33)



17

theshapeoftheelastomerandwhetheritisattachedtoametalthatmightbeattackedbymethanol.Complex-shapedelastomersmayreactdifferentlythantheuniformelastomershapesusedfortesting.

Methanolfuelsofalltypescanbeextremelyaggressivetowardmagnesiumand,iftheycontaindissolvedorseparatedwater,towardaluminum,also[36].Steelandotherferrousmetalsareusuallyonlyslightlyaffectedunlesstheblendhasaseparatedwaterphase,inwhichcasesomepittingmayoccur.Additiveshavebeenfoundtobeeffectiveinreducingthecorrosiveeffectsofmethanolingasoline(blendsofupto10%)oncopper,castiron,steel,andaluminum[37].Corrosioninside4-strokeenginescanbecontrolledthroughtheuseofproperlyformulatedengineoils[38].

Methanolblendfuelsoftencausematerialdeteriorationproblemswithnonmetalsusuallyinproportiontotheamountofmethanolintheblend.Methanol-richfuelshavebeenshowntocauseshrinkage,hardening,swellingorsofteningofcorkgasketmaterial,leather,Viton,andpolyurethane[36].Buna-N,Delrinacetal,high-densitypolyethylene,polypropylene,andNylon6/6showedgoodresistancetotheseeffectsinthesamestudy.Apotentiallyseriousproblemmayoccurinthereactiontomethanolfuelsdisplayedbypolyester-bondedfiberglasslaminateatsomewhatelevatedtemperatures(approximately118°F[47.8°C]).Softening,swelling,blistering,andsignsofdelaminationwereobservedinthispopularfuelstoragetankandtankliningmaterial[36].Reactionsatroomtemperatures(approximately73°F[22.8°C])werelesssevere,butstillnoticeable.Notethattheseissuesonlyrefertovehiclesdesignedforgasolinefuelonly.VehiclesdesignedforM85haveelastomerscompatiblewithmethanol.

d. oxyGen content

Gasolinesanddieselfuelproducedfromcrudeoilarecomposedentirelyofcompoundsthatarecomposedalmostentirelyofcarbonandhydrogenwithverysmallamountsofnitrogenandsulfur.Incontrast,methanolis50%oxygenwiththeremainderbeingcarbonandhydrogen.Asaresult,methanolneedslessairforcompletecombustionsincetheoxygeninitscompositiondisplacestheneedforoxygenintheair.Thestoichiometricair/fuelratioformethanol(weightbasis)is6.45(massairtomassmethanol)comparedtoabout14.7forgasoline.FigureV.8showstheimpactthishasonblendsofgasolineandmethanol.Asmethanolisaddedtogasoline,theoxygencontentoftheblendgoesup,but,sincetheoxygendoesnotcontributetoheatingvalue,thevolumeoffuelneededtogeneratethesamepowerincreases.(Thisdiscussionassumesthattheefficiencyoftheenginedoesnotchangewiththeamountofmethanol,whichisreasonableforfixedcompressionratioengines.)Thus,ablendof10%methanolingasolinerequiresapproximately105%ofthevolumeofstraightgasolinetomakethesameamountofpower.Ifanenginewerecapableofoperatingon100%methanol,itwouldrequiretwiceasmuchfuelvolumecomparedtoanenginerunningonstraightgasoline.

Theprecedingdiscussionassumestheengineisdesignedforgasolinebutisusingmethanolblendswithgasoline.Enginesoptimizedforuseofmethanolblendswheremethanolisthepredominatecomponent,suchas85%methanol(M85),canbemademoreefficientthroughuseofhighercompressionratiosandotherengineadjustmentsoptimizedtomethanol.Inaddition,anengineoptimizedforhighmethanolblendscanhavehigherspecificpoweroutput,creatingtheopportunitytoreduceenginedisplacementforagivenapplication.Withbothanengineoptimizedformethanolandreducedenginedisplacement,significantincreasesinenergyefficiencyarepossiblerelativetogasolineengines.


18

e. octAne VAlUe

Methanolhasgoodoctanepropertiescomparedtogasoline.Witharesearchoctanevalueof108.6andamodifiedmotoroctanevalue3of88.6,methanolhassufficientoctanetoallowenginesoptimizedformethanoltohavehighcompressionratioswiththeattendantbenefitsofimprovedpowerandefficiency.Whenusedinblends,thehighoctanevalueofmethanolcanbeusedtoreducetherefiningseverityoftheassociatedgasolineblendstock,allowingincreasesinrefineryoutputandefficiency.

3Thestandardmotoroctanetestmustbemodifiedtoincludefuelheaterstoenablemethanoltobetested.

fIgURe v.8 oxygen Content and Fuel volume ratio for Gasoline/methanol blends

1.0

1.1

1.2

1.3

1.4

1.5

1.6

1.7

1.8

1.9

2.0

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

Methanol Content

Fuel

Vol

ume

Ratio

for E

quiv

alen

t Ene

rgy

0%

5%

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15%

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25%

30%

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40%

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ent

vI. MeTHanol blend veHICle oPeRaTIonal IMPaCTsNovember 2007


19

VI. Methanol Blend Vehicle Operational Impacts

Becausemethanolblendshavealowerheatingvaluethanstraightgasoline,thevehicle’sfuelsystemmustbecapableofsupplyinganincreaseintotalfuelvolumeatalloperatingconditionstomaintainvehiclepower,driveability4,andcold-startperformance.Theamountofincreasedependsontheamountofmethanolintheblend,asillustratedinFigureV.8.Vehicleswithfeedbackfuelsystemsthatuseanoxygensensorintheexhauststreamwillbeabletocompensateuptotheexcessflowratebuiltintothefuelsystembydesign.However,theamountofexcessflowratebuiltintoavehiclefuelsystemvarieswitheachvehiclepowertrainfamilyandmayalsochangewithtime,asfuelpumpperformancedegradesanddepositsbuildupthatconstrictfuelflow.

Mostcurrenttechnologyfuelsystemshavethecapabilitytoadjustfuelflowinresponsetoenvironmentalfactorssuchasaltitude,temperature,humidity,andchangesinfuelpropertiesthataffectstoichiometry,suchashydrocarboncompositionandoxygencontent.Thiscapabilityiscalledadaptivelearningandtakesplaceafterthevehicleiswarmedup5andthefeedbackcontrolsystemisoperating.Theobjectiveofadaptivelearningistofine-tunethesystemtodithertheair/fuelratioaroundthestoichiometricvalueasdeterminedbytheoxygensensorsothatthethree-wayexhaustcatalystwilloperateefficiently.Asmethanolisaddedtogasoline,thestoichiometricair/fuelratiochanges,andthefeedbackcontrolsystemmustadjustaccordingly.

Engineoperatingmodeswhereadaptivelearningisnotineffectincludecold-start,warm-upbeforethefeedbackcontrolsystemisactive,prolongedidle,wide-open-throttleacceleration,andclosedthrottledeceleration.Duringthesemodes,changesinfuelstoichiometricair/fuelratiowillbereflecteddirectlyinvehicleoperationsincetheenginecontrolsystemhasnowayofdetectingthatadifferentfuelisbeingused.

A. cold-StArt

Methanolhasseveralcharacteristicsthatincreasethedifficultyofcold-startininternalcombustionengines.Themostimportantoftheseisthehighflashpointofmethanolcomparedtogasoline.Methanol’sflashpointis52°F(11°C)comparedtogasoline,whichhasatypicalflashpointof-43°F(-45°C).Thusanengineconfiguredtousemethanolinsteadofgasolinewillnotstartbelow52°Fwithoutexternalstartingaids.

Anotherlargedifferenceisthatmethanolrequiresabout3.5timesmoreenergyperunitmasstovaporizeitcomparedwithgasoline.Factoringintheneedfortwiceasmuchmethanolasgasolinetoproducethesamepower,thedifferenceisafactorof7.Thefactthatmethanolisahomogeneousliquidwithasingleboilingpointcombinedwiththeneedformuchmoreenergytovaporizeitresultsinmuchlessvaporgenerationattypicalstartingtemperaturesthangasoline,whichhassomehydrocarbonsthatvaporizeatlowtemperatures.

4 Driveabilityisameasureofvehicleoperationalproblemssuchasstallingorsurgingduringwarm-up,unstableidle,unevenacceleration,non-linearthrottleresponse,occurrenceofvaporlock,etc.Gooddriveabilityisanabsenceofoperationalproblems.5Being“warmed-up”generallymeansthreecriteriahavebeenmetforvehicleswithcatalystemissioncontrolsystems:1)theoxygensensortemperatureisaround600°F,2)thecoolanttemperatureisaround150°F,and3)apredeterminedamountoftimehaselapsedfromthetimetheenginehasstarted(fromafewsecondsto1-2minutes).

November 2007Use of MeTHanol as a TRansPoRTaTIon fUel vI. MeTHanol blend veHICle oPeRaTIonal IMPaCTs

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Whenmethanolisblendedingasoline,itadverselyaffectscold-startcapabilityinanumberofsimilarways.Whilemethanoldepressesthelowerenddistillationofthegasolineintowhichitisblended,thevaporthatisgeneratedhasdisproportionatelymoremethanolinitmakingthevaporleanerthanthatfromstraightgasoline.Thehigherlatentheatofvaporizationofmethanolmakesthevaporgeneratedmoredifficulttoheatup,resultinginlowertemperaturesduringstartingevents.Ablendof5%methanolingasolineneeds14%moreenergytovaporizecompletely[32],withmostofthatdifferenceaccountedforbefore50%distilled,asillustratedinFigureV.2.Moreover,ifthegasolinehashaditsfrontendvolatilityadjustedtocompensatefortheazeotropingeffectwhenmethanolisadded,thelowboilinghydrocarbonsthatprovidemuchofthevaporforcold-weatherstarting,suchasbutane,willhavebeenreduced,causingfurtherdetrimenttocold-startingcapability.

InOtto-cyclesparkignitionengines,morefuelisintroducedduringcold-startthanisnecessaryforcompletecombustionsothatsufficientfuelvaporisgeneratedtogetintotheflammablerange.Intestingconductedwithgasolineat-22°F(-30°C),itwasfoundthattheamountofgasolineneededtoachievecold-startwaseighttimesthestoichiometricvalue.Withablendof10%methanolhavingthesameRVPasthegasoline,itwasfoundthatfuelneededtobeaddedattherateof14timesthe

stoichiometricvalue[32].Despitetheadverseimpactsaddingmethanolcanhavetocold-startperformance,fleettestsoflow-levelmethanolblendsdidnotreportstatisticallysignificantchangesincold-startperformance.

B. driVeABility

Ownersofmodernvehiclesexpectnearlyflawlessoperationintermsofdriveability,whichincludesnostallingorsurgingduringwarm-up,idleataconstantspeed,smoothaccelerationwithoutstumblesorsags,linearthrottleresponse,andabsenceofvaporlock.Asexplainedpreviously,addingmethanoltogasolinecausestheenginetooperateleaner,especiallyduringcold-startandwarm-up,whendriveabilitydefectsaremostlikely.TestingbyGeneralMotorshasshownthataddingmethanoltogasolineisequivalenttooperatingwithaleanercalibrationusinggasolineintermsofcausingdriveabilitydemerits(seeFigureVI.1).Recenttestsofexistinggasolinevehiclesusingupto30%ethanolwithoutdriveabilityproblemssuggeststhatcurrentvehiclesthathavefeedbackemissioncontrolsystemshavethecapabilitytocompensateforlow-levelmethanolblendsandshouldnothavedegradeddriveability.

fIgURe vI.1 Adding methanol to Gasoline is equivalent to Leaner Gasoline Calibration in Terms of Driveability (Source: ref. 32)

15 10 5 0 5

240

200

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10 volume % methanol

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10 volume % ethanol

Driveability, CRC Total Weighted Demerits, Cold Start Procedure at 50 to 60°F

Lean Stoichiometric Rich

Mixture StrengthDecrease Increase

vI. MeTHanol blend veHICle oPeRaTIonal IMPaCTsNovember 2007


21

c. AccelerAtion

Whenadriverevaluatesacceleration,itisoftennotjusthowquicklythevehiclewillaccelerate,butthequalityofthatacceleration(i.e.,linearthrottleresponse,nosurgesorstumbles,etc.).Ifthevehicleisnotfullywarmedup,methanolblendscancausethevehicletoexhibitsloweraccelerationandthedriveabilityproblemsjustidentified.Whenthevehicleisfullywarmedup,thedrivermaynotnoticeanychangeifthefuelsystemcompensatesforthemethanoladditionthroughthefeedbackcontrolsystem.However,ifthevehiclespendsasignificantamountoftimeatfull-throttle,accelerationmaybeimpacteddependingonthefull-throttlecalibrationusinggasoline.Forexample,testsofearlycarburetedvehiclesinBrazilcalibratedtouse20%ethanolfoundthataccelerationwasbetterusing20%ethanolthanstraightgasoline[39].Thereasonwasthatthecalibrationwastoorichformaximumaccelerationwhenusingstraightgasoline,whileusing20%ethanolmadethestoichiometryclosertothebestvalueformaximumpower.Allthingsequal,useofmethanolresultsinfasteraccelerationbecauseitshigheroctaneandlatentheatofvaporizationallowformoresparkadvancethangasoline.Enginesoptimizedformethanolcaneasilybemorepowerfulthansimilardisplacementgasolineengines,withtheresultbeingfasteracceleration.

d. fUel econoMy

AsshowninFigureV.8,addingmethanoltogasolinereducestheheatingcontentperunitvolumeoffuel.Controlleddynamometertestshaveshownthataddingmethanoltogasolinereducesfueleconomy(seeFigureVI.2)[40].However,whenthechangeinenergycontentwastakenintoaccount,therewasnochange,indicatingthattheengineefficiencywasnotaffected.(Notethat30%methanolwasthemaximumblendthisvehiclecouldaccommodatewithoutdriveabilityproblems.Cold-startingusing30%methanolwasnottested.)Vehicleusersexperienceawiderangeoffueleconomiesdependingonweatherandonhowthevehicleisused,andmaynotbeabletodistinguishtheimpactsoflow-levelmethanolblends.

0 5 10 15 20 25 30% Methanol Blend

Mile

s pe

r Gal

lon

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15.0

10.0

5.0

0

fIgURe vI.2 Impact of methanol blends on Fuel economy (Source: ref. 40)

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fIgURe vI.3 Impact of methanol blends on energy economy (Source: ref. 40)

November 2007Use of MeTHanol as a TRansPoRTaTIon fUel vII. eMIssIons IMPaCTs

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VII. Emissions Impacts

A. priMAry reGUlAted exhAUSt eMiSSionS

Methanolhassomeinherentemissionadvantagesovergasolinewhencombustedininternalcombustionengines.EmissionsofCOareafunctionofcombustionstoichiometryandwillnotbesignificantlydifferentfromgasolinecombustionasthesamestoichiometry[33].Likewise,HCemissionswillbesimilarinmagnitudecomparedtogasoline,butunburnedmethanolhassignificantlylowerreactivityasanozoneprecursorintheatmospherecomparedwithmostgasolineHCs.Thisadvantageisoffsetsomewhatbyincreasedformaldehydeemissionsfrommethanolcombustion,butmoderncatalystsystemsareveryeffectiveatreducingformaldehydeemissions,resultinginanetbenefitformethanolovergasoline.FigureVII.1showsgeneralengine-outemissiontrendsforCOandHCswithstoichiometryformethanolcombustion.

EmissionsofNOxaretypicallylowerthanthosefromgasolinewhenmethanoliscombustedundersimilarengineconditions(seeFigureVII.2).Thisisdueprimarilytothelowerpeakflametemperatureofmethanol,andsecondarily,tothehighlatentheatofmethanol,whichreducespre-ignitiontemperatures.Whenoperatinganengineatconstantcompressionratio,substituting100%methanolforgasolinehasbeenshowntoreduceNOxemissionsby30%[40,41].Thisadvantageissignificantlynegatediftheenginecompressionratioisincreasedand/orotherenginechangesaremadetomaximizethespecificpowerpotentialofmethanol.ResearchbyVolkswagenshowedthatincreasingthecompressionratioto13:1totakeadvantageofmethanol’shigheroctaneincreasedengine-outNOxemissionstothesamelevelasforgasolineatacompressionratioof8:1[42].However,withmodernthree-waycatalystsystems,theinherentadvantageoflowerengine-outNOxemissionsisnotasignificantadvantage.

Recentdevelopmentofthehomogeneouschargecompressionignition(HCCI)combustionsystemholdspromiseforinternalcombustionenginesusingneatmethanolasfuel.WhenmethanolisusedinHCCI

NOx EMISSIONS

10% Methanol / Gasoline Blend

Emis

sion

Con

cent

ratio

n

Lean 1.0 Rich

Equivalence Ratio

Stoichiometric

Gasoline

Methanol

fIgURe vII.2 engine-out Nox emission Trends Compared to Gasoline at Constant Compression ratio (Source: ref. 33)

CO and HC EMISSIONS

Emis

sion

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cent

ratio

nLean 1.0 Rich

Equivalence Ratio

Stoichiometric

CO

HC

fIgURe vII.1 engine-out Co and HC emission Trends (Source: ref. 33)

vII. eMIssIons IMPaCTsNovember 2007


23

engines,emissionsofNOxcandecreasetonear-zero[43].HCCIengineshavethepotentialtoreplacebothgasolineanddieselengines.

Blendsofmethanolandgasolineaffectvehicleemissionsaccordingtotheamountofoxygenintroducedintotheblendfromthemethanol.FigureVII.3showsgeneraltrendsandconfidenceintervalsfortestsofmanyvehiclesusingarangeofmethanolblends(includingco-solvents)[44].Thesearetailpipeemissionsfromtypicalemissioncontrolsystemsforvehiclesofthatera(early1980s),whichincludedanoxidationcatalyst.Theadditionofoxygenthroughmethanolanditsco-solventscausesthefuelstoichiometrytomoveleanerwiththeresultthatCOandHCsarereducedwithNOxincreasingslightly.TheseresultswerecorroboratedbytheCoordinatingResearchCouncilintestsperformedfortheU.S.DepartmentofEnergy[45].

TheU.S.EnvironmentalProtectionAgency(EPA)testedsixin-usepassengercarschosentohavefuelandemissionsystemsrepresentativeofpopularonesinusein1995,usingblendsofupto40%ethanolingasoline[46].Thevehicleswere1990and1992models,allequippedwithfuelinjectionandthree-waycatalystfeedbackemissioncontrolsystems.Thegasolineusedwasrepresentativeofasummer-timegasolineandtheethanolwassplash-blended(i.e.,thehydrocarbonportionwasnottailoredforethanolblending).AlltheemissionstestswereconductedonachassisdynamometerusingtheFederalTestProcedure.Whilethesetestswereconductedusingethanol,theyarerepresentativeofmethanolblendsupto28%basedonthesameoxygencontent,whichistheprimarydriverincriteriaemissionschanges.(Therewasnoindicationwhetherthesevehicleswouldhaveacceptabledriveabilityatthehigherblendlevelstested.)

WhilethemagnitudeoftheemissionchangesvariedamongthesixvehiclesEPAtested,theyallshowedthetrendsillustratedinFigureVII.3.Basedonalinearregressionoftheresults,EPAfoundthatthesevehiclesonaverageshoweda45%reductioninCOemissionsat14%oxygenintheblend(theequivalentof40%ethanolor28%methanol).ForHCs,thereductionwas32%whileNOxincreased64%.Thus,whilethesevehicleswereatleasttenyearsnewerthantheonestestedtodevelopthedataofFigureVII.3,thesametrendspersisted,nodoubtduetothefactthatmostemissionsfromvehicleswithmoderncatalyticemissioncontrolsystemsoccurduringopen-loopoperation,e.g.,cold-start,warm-up,andwide-open-throttleacceleration.Itshouldbenoted,however,thatthesevehicleshaddiminishedresponsetofueloxygencontentcomparedwiththedataofFigureVII.3,thoughstillsignificant.

Amorerecentstudyusinglate-modelvehiclesfueledwith20%ethanol(7%oxygen)wasconductedbyOrbitalEngineCompany

fIgURe vII.3 emission Trends for blends of methanol in Gasoline (Source: ref. 44)

Ratio

of T

est F

uel R

esul

t/Bas

e Fu

el R

esul

t

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1.0 = No change1.0

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Regression Lines and 95% Confidence Intervals

NOx

HC

CO


24

forEnvironmentAustralia[47].Theytestedfive2001modelyearvehicles,withallofthemhavingelectronicfuelinjectionandthree-waycatalystemissioncontrolsystems.ThesevehicleswerechosentoberepresentativeofthefleetinAustralia,buttheyhavethesamefuelandemissioncontrolsystemsastheircounterpartsinotherpartsoftheworld,exceptforperhapsdifferentcalibrations.

TheemissionsofthesevehiclesweretestedusingtheU.S.FederalTestProcedure,thesameasEPAusedinitstestprogram.Orbitalfoundthatonaverage,HCemissionsdecreasedby30%,COemissionsdecreasedby29%,andNOxincreasedby48%whenusing20%ethanol.TheseresultsaresimilarindirectionbutlargerthanwhatEPAhadfound(i.e.,16%decreaseintotalHCs,22%decreaseinCO,and32%increaseinNOxat7%oxygen).OnedifferencebetweenthesetwogroupsofvehiclesisthattheOrbitalvehicleswerepurchasednewandwereoperated4,000milesbeforeemissionstestingwasconducted,whilethevehiclestestedbyEPAwerein-usevehicles(theirindividualmileageaccumulationswerenotlisted).Itshouldalsobenotedthatpercentchangeinemissionsisbeingcomparedamongthesethreegroupsofvehicles,notabsoluteemissionslevels,whichweredifferentforallthevehiclestested.

Thesechangesinemissionsareindicativeoftheinabilityofthefuelsystemstocompensatecompletelyunderallcircumstancesfortheoxygenadditionfromtheethanol.Onepotentiallong-termimpactoftheoxygenadditionismorerapiddeteriorationofthecatalyst.Orbitalmeasuredcatalysttemperaturesthatwerehigherduringwide-open-throttleusing20%ethanolcomparedtostraightgasolineineveryvehicleduetotheinabilityofthefuelsystemtomaintainthedesiredstoichiometry.Elevatedcatalysttemperaturesduringwide-open-throttlecausemorerapidcatalystdeteriorationandincreasesinallemissionsasthecatalystdegrades.ThisisinfactwhatOrbitalfoundafterdrivingitsvehiclesfor80,000km(50,000miles)andretestingemissions[48].OnlytwoofthefivevehiclesshoweddecreasedHCandCOemissionsat50,000miles,whileallthevehiclesshoweddecreasesinHCsusing20%ethanolduringtestingat4,000miles.FouroutoffivevehiclesshowedanincreaseinNOxat50,000milesusing20%ethanol,whichisthesameresultaswasobtainedduringthe4,000miletestingexceptthatthevehiclesshowingthedecreasewerenotthesameat4,000and50,000miles.Orbitalinvestigatedthevehiclewiththemostemissionsdeteriorationandfoundthatthecatalysthadalargedecreaseinconversionefficiency,withhighercatalystoperatingtemperaturesbeingthemostlikelyreason.Thisvehiclehadalowpower-to-weightratioandthereforeoperatedathighengineloadsforagreaterpercentageofthetime,whichaccelerateditscatalystdeteriorationduetohigherexhausttemperatures.Theeffectontheothervehicleswassimilarbutmoregradual.

ThesetestprogramssuggestthatusingintermediatetohighlevelmethanolblendsinvehiclesnotdesignedforthemcanreduceCOandHCemissionsintheshortterm,butcauseincreasesinallemissionsoverthelongtermifthecatalystismorerapidlydegraded.

B. cArBon dioxide eMiSSionS

Thepredominatecompoundfromthecombustionofmethanoliscarbondioxide,asfromgasoline.Forthesameamountofenergy,methanolwillproduce94%asmuchcarbondioxideasgasoline.Enginesthathavebeenoptimizedformethanolwithincreasedefficiencywillhavelowercarbondioxideemissions.TheGreenhousegases,RegulatedEmissions,andEnergyuseinTransportationmodel(GREET)maintainedbyArgonneNationalLaboratoryshowscarbondioxideemissionsforflexible-fuelvehiclesusing85%methanol(M85)tohavecarbondioxideemissionsthat



25

are96%thoseofasimilarvehicleusinggasoline[49].Thisincreaserelativetoneatmethanolisdueprimarilytothe15%gasolineinM85.GREETalsoincludesa“neat”methanolvehiclethathasbeenoptimizedforM90.This“neat”methanolvehiclehascarbondioxideemissionswhichare89%thoseofasimilargasolinevehicle.ThedecreaserelativetotheM85vehicleisdueprimarilytothebuilt-inassumptioninGREETthatthe“neat”methanolvehicleis7%morefuelefficientthanthesimilargasolinevehicle.Methanolvehicleswithenginesoptimizedformethanolcouldachieveevengreaterfuelsavingswithcorrespondingdecreasesincarbondioxideemissions.

c. toxicS

Whenmethanoliscombusted,theHCemissionsarecomposedprimarilyofunburnedmethanolandaldehydes,withformaldehydebeingdominant.Testinghasshownthatneatmethanolwillproduceabouttwicethelevelofaldehydesasgasoline[50](seeFigureVII.4forgeneraltrendsinaldehydeemissionsfrombothmethanolandgasoline).Testsofneatmethanolvehicleshaveshownthatformaldehydeisthepredominanttoxicemissionfrommethanolcombustion[51].Aldehydeemissionsareeffectivelycontrolledbyuseofacatalyticconverter.

Gasolineproducesadditionaltoxicssuchas1,3-butadiene,benzene,hexane,toluene,andxylene,whicharisefromvarioushydrocarbons.Whenmethanolisaddedtogasoline,productionofthesetoxicsiscorrespondinglyreduced.Inaddition,ifthemethanoladditioncausesaleanshiftinstoichiometry,theoveralldecreaseinHCemissionsassociatedwiththatshiftdecreasestoxicemissionsinproportion.

d. eVAporAtiVe eMiSSionS

Neatmethanolproduceslowerlevelsofvaporcomparedtogasolinebecauseofitshigherboilingpointcomparedtotheinitialboilingpointofgasoline.EarlyworkbyUnionOilCompanyfoundthatmethanolvapordegradedtheabilityofautomotivecharcoalcanisterstoadsorbvaporscomparedtogasoline[36].However,theM85vehiclesproducedandusedintheU.S.metthesameevaporativeemissionstandardsascomparablegasolinevehiclesandlong-termdeteriorationofthecharcoalwasnotreportedasaproblem.

ALDEHYDE EMISSIONS

Methanol

10%Methanol/GasolineBlend

GasolineStoichiometric

Lean 1.0 Rich

Equivalence Ratio

Aldehydes

Emis

sion

Con

cent

ratio

n

Figure vII.4 Aldehyde emission Trends for methanol and Gasoline (Source: ref. 33)


26

AsexplainedinSectionV,addingmethanoltogasolinewillgreatlyincreasetheamountofvaporgeneratedalongthelowerhalfofthegasolinedistillationcurve.Sincevehicleevaporativesystemsaresizedforgasoline,addingmethanoltogasolinethathasnotbeenmodifiedtoreduceitsfrontendvolatility(0to50%distilled)willalmostcertainlyresultinsaturationofthecanisterand,consequently,veryhighevaporativeemissions.Inresponsetorequestsforuseofmethanol/gasolineblendsintheU.S.,theEPAdevelopedamodifiedevaporativeindextocapturethechangemethanolcausestogasolinefrontendvolatility.Methanol/gasolineblendsthatmeetthemodifiedevaporativeindexshouldnotcauseincreasesinevaporativeemissions.InoneofEPA’srulingsonamethanol/gasolinewaiverrequest,theycommentedthatproperlyformulatedblendswillnotdecreasetheabilityofthecarboncanisterstoadsorbvapors[52].ForevaporativeemissionscertificationofM85vehicles,EPArequirestestsusingM85,straightgasoline,andtheblendofthetwowiththehighestvaporpressure[53].

Asfuelsystemshavemovedawayfromsteeltanksandlinestoplastic,permeationemissionsfrommethanolandmethanolblendsislikely.(Permeationistheevaporationoffuelthroughelastomericmaterialsusedinthefuelsystem,butprimarilyfromthelinesandtanks.)IntheU.S.,testinghasbeendonetomeasurethepermeationemissionsofethanolblendsingasoline.Itwasfoundthattheethanolinethanolblendstendedtobepreferentiallyabsorbedintotheplasticfuellinesandtanks,andthenevaporatedawayfromthesurface[54].Sincetheimpactofmethanolonelastomersissimilartothatofethanol,andinsomecasesworse,itislikelythatmethanolblendswillcausepermeationemissionsaswell.Permeationemissionscanbepreventedbypropermaterialselectionanddesignchanges.Forexample,treatmentsforplastictankshavebeendeveloped(florinationandsulfonation)toreducepermeationlosses.Multi-layerfueltanksthatcontainacontinuouslayerofareducedpermeationcomponentinthemiddlehavealsobeendeveloped.Whilethetechniquestoreducepermeationundoubtedlycostmorethanplainplastictanks,theyarethesametechniquesusedtoreducepermeationemissionsfromgasolinevehiclesdesignedtomeetthemoststringentevaporativeemissionsstandards,i.e.,thePZEV(partialzero-emissionvehicle)standardinCalifornia.Asmorestringentevaporativeemissionstandardsbecomemoreprevalent,thecostdifferentialformethanolvehicleswithsuchfuelsystemswillbecomeinsignificant.

e. “Well-to-Wheel” GreenhoUSe GASeS

Whilemethanolcombustiondoesnotresultinsignificantlydifferentemissionsofcarbondioxidecomparedwithgasoline,thesituationchangeswhentheentireresource-extraction-through-end-usepathisconsidered.ThistypeofassessmentoftheGHGsfromtransportationvehiclesisknownas“well-to-wheels”.Inthiscase,itisassumedthatthemethanolisusedininternalcombustionenginevehiclesspecificallydesignedformethanol,whichtakeadvantageofmethanol’spropertiestoincreaseefficiency.

TheGREETmodelwasusedpredominatelyforthisanalysis[49].GREETonlyincludespreliminarynumbersformethanolfromcoalandmethanolfrombiomass.Anindependentestimateofthewell-to-wheelsGHGsofmethanolfromcoalwasmadeforthisanalysis.

Thefollowingmethanolproductionresourceswereincluded:

NaturalgasCoal

−−



27

CoalwithsequestrationofcarbondioxideBiomass

Thenaturalgascaseisincludedasabenchmarkforcomparisonsincenaturalgasisthepredominateresourcecurrentlyusedtoproducemethanol.However,itshouldbeunderstoodthatthisnaturalgascaseisspecifictoNorthAmerica–methanolmadefromnaturalgaselsewhereorunderspecificcircumstancescouldhavehigherorlowerGHGs.ThecoalcasesarealsospecifictoNorthAmericaandassumeuseofbituminouscoal(propertiestakenfromGREET).Twolevelsofsequestrationareincluded:75%efficiencyreflectiveofcurrenttechnologyand90%efficiencywhichistheU.S.DepartmentofEnergygoalfor2012[55].Methanolfrombiomassisassumedtousewoodastheresourcewithgasificationtechnology.

Themethanolinternalcombustionenginevehiclesareassumedtobe7%moreefficientthantheirgasolinecounterparts[49].Thereasonsincludehigheroctanevalue,lowercombustiontemperature,andmoreefficientcombustion.

FigureVII.5showstheresults.Methanol(MeOH)fromnaturalgasisprojectedtoproducejustslightlylessGHGsthangasoline–thisisdueprimarilytotheassumptionthatmethanolvehiclesare7%moreefficient.WiththerangeofGHGemissionspossiblefrombothgasolineproductionandmethanolproductionfromnaturalgas,itismostlikelythatthisdifferenceisnotsignificant.MethanolfromcoalwithoutsequestrationproducesalmosttwicetheGHGsofgasoline–aresultthatisnotunexpectedgiventhehighcarboncontentandlowhydrogencontentofcoal.Methanolmadefromcoalwithtoday’slevelofcarbonsequestrationefficiencyshowsverysimilarGHGemissionscomparedtogasoline–improvementincarbonsequestrationcouldlowerGHGsabout15%further.Finally,methanolfrombiomasshasanetGHGcreditbecauseallthe

−−

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fIgURe vII.5 methanol “Well-to-Wheel” GHGs from various resources


28

carbonusedtomakeitisrenewable(i.e.,thecarbonemittedissequesteredbackintothegroundbyregenerationofthefeedstock)

Thecoalcaseshereassumeplantsthatonlymakemethanol.Plantsthatcombinemethanolproductionwithelectricitygenerationhavethepotentialtoproducemethanolmoreefficientlythanstand-aloneplants.TheefficiencyofproducingmethanolusingtheAirProductsLPMEOHTMmethanolproductiontechnologyhasbeenestimatedtobe71%,comparedwiththe55%assumedhereforstand-aloneplants[56].MethanolproducedinthesefacilitieswouldhavecorrespondinglylowerGHGs.

vIII. InfRasTRUCTURe IMPaCTs November 2007


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VIII. Infrastructure Impacts

Methanolismadeinnumerousplacesaroundtheworldandisoftentransportedviaoceantankertovariouscountriesthatconsumeit.Thissectionfocusesonthedistribution,storageandretaildispensingofmethanolwithincountriesforuseintransportationvehicles.

A. diStriBUtion

Methanolistypicallyshippedviarailroadtankcar,barge,andtrucktanker,dependingonvolumeanddistance[57].IntheU.S.,onlyaverysmallamountofmethanolissentthroughpipelines,andonlyoververyshortdistances[58].Pipelinetransportisthemostcost-effectivelong-termmethodfortransportingfuelsbecauseofthevolumesanddistancesinvolved.Manycountrieshavepipelinesforthetransportofpetroleumproducts,butusingthesepipelinestotransportmethanolfacesseveralhurdles.Duringtheintroductionofmethanol,methanolmovementwouldinitiallyrepresentasmallminorityofalltheliquidfuelbeingtransportedviapipeline.Intermittenttransportofmethanolinpetroleumpipelinesfacestheproblemsofpotentialinterfaceminglingandtheneedforadditionalstoragesuitedformethanol.Wherepetroleumproductsaretakenoutofthepipeline,thecut-pointisdesignedtoprotecttheproductthatwouldbemostunacceptablydegraded,whileleavingasmuchoftheinterfaceinaproductthatwouldnotbedegraded,ifpossible.Forexample,methanolcouldpossiblybeshippedneat,wrappedwithdifferentclassesofgasolineateachend.Theinterfacecouldstaywiththemethanol,thusprovidingsomeofthegasolinethatwouldotherwisebeblendedtoproduce,forexample,M85.Theproliferationofdifferentproductsforpipelinestowrap,however,makessucharrangementsincreasinglycomplicated.Ifmethanolhadtobewrappedwithproductsotherthangasoline,suchcuttingwouldbeunacceptable.Inthosecases,muchoftheinterface–the“transmix”–wouldhavetoberemovedandreprocessed,possiblybyasmallregionaltransmixseparatorbutinsomecasesitwouldhavetobeshippedbacktoarefinery.Suchseparationswillbemuchmoredifficultwithinterfacescomposedofmethanolandpetroleumfuel.

Inaddition,themethanolwillremoveanyexistingwaterandpetroleumresiduesinthepipeline,furtherdegradingthequalityoftheinterfacevolume.

Onetechniquetominimizeinterfacevolumeisthroughtheuseofadevicethatphysicallyseparatesbatcheswithinapipeline,commonlycalleda“pig.”Theuseofpigsmaynotsolvethewateruptakeanddepositremovalproblem,however,anditisunknownhowfrequentlyitispracticaltosendpigsthroughtheline(pipelinesgenerallyonlygoinonedirection–thepigswouldhavetobetransportedbacktotheplaceoftheirinsertion).Theseissuesandotherswillneedtobeexploredbeforeitwillbeknownwhethershipmentofmethanolthroughexistingpetroleumpipelineswillbepractical.

Someexistingpipelinesmaybedivertedtodedicatedmethanoluse.Oncethesepipelinesarecleaned,theywillnothavetheproblemsassociatedwithintermittentuseinpetroleumpipelinesjustdiscussed,andwaterpick-upandresidueremovalshouldnotbeproblems.Evenso,potentialmaterialcompatibilityissueswithexistingpipelinesrequireresearch,andtheavailabilityofstoragetankssuitabletostoremethanolremainsaquestionwhenusingexistingpetroleumpipelinesfordedicatedmethanoltransport.

November 2007Use of MeTHanol as a TRansPoRTaTIon fUel vIII. InfRasTRUCTURe IMPaCTs

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B. StorAGe

Bulkstorageofmethanolshouldbedoneinappropriatelydesignedhorizontalorverticalstoragetanks.Tolimitmoistureinfiltration,aconservationventwithaflamearrestorisrecommended,ornitrogenblanketing.Propergroundingisessential,givenmethanol’slowconductivity.

Forstorageatretailservicestations,theundergroundtankispreferred.Undergroundstoragehasseveraladvantages:thefuelstaysatarelativelyconstantcooltemperature;theabove-groundspaceismaximizedforvehiclerefueling;andrefillingfromtankertruckscanbedoneusinggravityratherthanapump.Tanksformethanolcanbemadefromstainlesssteel,carbonsteel,ormethanol-compatiblefiberglass.IntheU.S.,methanoltanksplacedundergroundmusthavesecondarycontainmentbecausemethanolisclassifiedasahazardouschemical.Secondarycontainmentincludes:

Double-walledtanksPlacingthetankinaconcretevaultLiningtheexcavationareasurroundingthetankwithnaturalorsyntheticlinersthatcannotbepenetratedbymethanol

Forundergroundmethanoltanksatservicestations,conservationventswithflamearrestorsaretypicaltopreventwaterabsorptionratherthannitrogenblanketing.Conservationventsareusuallyconfiguredtoallowventingtooccuronlywhenthepressureinthetankexceeds7-21kPa(1-3psi),andwhenthevacuuminthetankexceeds5-10cm(2-4inches)ofwater[59].Thisisespeciallyimportantwhenstoringneatmethanolsincethevaporspaceinthetankwillbeflammable,unlikestorageofgasolineorM85wherethevaporspacewillbetoorichtobeflammable.

Existingundergroundpetroleumtanksmustbethoroughlycleanedbeforestoringmethanoltoremoveallwaterandsediment.Someundergroundstoragetanksuselinerswhichmustbemethanol-compatible.

Inadditiontomoistureinfiltrationfromtheair,wateroftengetsintoundergroundstoragetanksfrominadequatesealsontherefillingmanholes.Effortsshouldbemadetopreventwaterinfiltrationfromthesurfaceabovesincethiswateroftenincludesimpuritiessuchassodiumandchlorideionsthatgreatlyincreasethecorrosivenessofmethanol

c. SerVice StAtionS

Servicestationsmustbecapableofmovingmethanolfromtheundergroundstoragetanktothedispenserandintothevehicle[60].Mostundergroundstoragetanksusesubmersiblepumps,whichmusthavematerialscompatiblewithmethanol.Asthemethanolispumpedfromtheundergroundtank,ittravelsthroughpipingtothedispenser(seeFigureVIII.1).Liketanks,pipingformethanolcanbemadefromstainlesssteel,carbonsteelormethanol-compatiblefiberglass.IntheU.S.,pipingcomesunderthesamerulesasundergroundtanks,i.e.,double-walledpipingorsecondarycontainmentisrequired.

−−−

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Forthreadedpipeconnections,Teflon®tapeorpasteispreferredforusewithmethanol.Pipedopeintendedforusewithgasolinewillbedissolvedbymethanol,creatingleaks.Boltedconnectionsmustusegasketscompatiblewithmethanol.

Dispensersdesignedforpetroleumfuelstypicallyusesteel,castiron,aluminum,brass,bronze,andstainlesssteel.Ofthese,onlythesteelsandcastironarecompatiblewithmethanol.Inaddition,dispensersuseseveralgasketsandelastomerswhichareunlikelytobemethanol-compatible.Dispensermanufacturershavedevelopedunitscompatiblewithmethanol;thesemustbeusedtopreventmalfunctionandfirehazardsfromleaks.

Mostdispensersincludefilters,bothspin-onandthosewithreplaceableelements.Themostdurablefiltersincludenylonfilterelementsandmethanol-compatibleadhesives.Becausemethanolisveryaggressivetomanymetalsandbecausetheproductsofcorrosioncancauseproblemsinmethanolvehiclefuelsystems,itisrecommendedthatmethanolfilterelementporesbe3µmmeandiameter,insteadofthe10µmmeandiametertypicalofthoseforgasoline[59].

Filterelementswithsmallmeandiameterporesaremoresusceptibletobuild-upofstaticelectricity.Thisisparticularlyaproblemformethanolbecauseofitslowconductivity.Inseverecases,thedischargeofstaticelectricityfromthefilterelementtothehousingcancauserapiderosionofthehousingfromtheinside,eventuallycausingaholetoappear.Changingthefilterbeforeback-pressurebuildssignificantlywillminimizebuild-upofstaticelectricity.

Whenusedformethanol,dispensinghosesdesignedforgasolinewillrapidlydegradeandputdebrisintothevehicle,whichwill,inturn,clogitsfuelfilter.Evenmethanol-compatibledispensinghoseshavebeenfoundtoreleaseplasticizersandshouldbesoakedfor24hoursinmethanoltoremovethembeforeinstallation[59].Break-awayfittingsarerecommendedformostdispenserapplicationsandneedtobemethanol-compatible.

Conventionalnozzlesdesignedformethanolareavailable,butabettersolutionisthe“dry-break”or“spill-free”nozzle.Thespill-freenozzle(seeFiguresVIII.2andVIII.3)wasdeveloped

fIgURe vIII.1 methanol refueling Station Schematic (Source: ref. 60)

November 2007Use of MeTHanol as a TRansPoRTaTIon fUel vIII. InfRasTRUCTURe IMPaCTs

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bytheMethanolFuelCellAlliance,anindustryconsortiumledbyBASF,BP,DaimlerChrysler,Methanex,Statoil,andBallard[61].Fiberopticcommunicationsarebuiltintothenozzleandthevehiclefuelreceptacletoensureproperfuelingwithoutanelectronicinterface.Useofsuchanozzleeliminatesspillsandconcernaboutfiresafetyandhumancontactwithmethanol[62].

fIgURe vIII.3 The Identic Spill-Free methanol refueling Nozzle In Use (Source: ref. 62)

fIgURe vIII.2 The Identic Spill-Free methanol refueling Nozzle In Use (Source: ref. 61)

Ix. MeTHanol Use In dIesel Heavy-dUTy veHIClesNovember 2007


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Ix. Methanol Use in Diesel Heavy-Duty Vehicles

Thephysicalandchemicalpropertiesofmethanolmakeitverywell-suitedforuseasaspark-ignitionenginefuel,butitsabilitytocombustwithoutformingsoot(duetothelackofcarbon-to-carbonbonds)hasattracteddieselenginedesignerstofindwaysofusingitaswell.Manywaysofusingmethanolindieselengineshavebeenresearchedincludinguseinblends,emulsions,fumigation,withtheadditionofignitionimprovers,indualinjectionengines,andinenginesmodifiedtoachievedirectcompressionignitionofmethanol[63].Notethatofthesemethods,onlyuseofignitionimproversandcompressionignitionresultedinenginesthatdisplacedalldieselfueluse,thoughcompletedisplacementwasnotviewedasarequirementsincetheemissionsbenefitsofmethanolweretypicallygreaterthanthepercentdieselfuelitreplaced.Dieselenginescouldalsobeconvertedtosparkignition,butthischangeessentiallychangesthemtobeOttoCycleengines.Numerousfleettestsofheavy-dutyvehicleswithmethanolengineshavebeenconducted[64,65,66,67].

A. USe of MethAnol in BlendS With dieSel fUel

Methanolhasverylimitedsolubilityindieselfuel(onlyafewpercent)andwasnotconsideredseriouslyasameansofusingitindieselengines.Otheroxygenateshavebeenseriouslyconsideredforblendingintodieselfuel[68].

B. USe of MethAnol in eMUlSionS With dieSel fUel

Theverylimitedsolubilityofmethanolindieselfuelledtoextensiveresearchtofindwaysofusingmethanolthroughemulsions[63,69].Throughtheuseofemulsions,itwasfoundpossibletoaddlargeamountsofmethanoltodieselfuel(testsusing10-30%werecommon).Thedisadvantagesfoundtomethanolemulsionsincludedthefollowing:

Roughlyanequalamountofemulsifierwasneededasmethanol,makingthefuelexpensive.Theadditionofmethanolquicklydegradedthecetanenumberoftheemulsion,necessitatingengineinjectiontimingchangesoradditionofanignitionimproveradditive.Emulsionsbecomequiteviscousatlowtemperaturesandtendtoseparateinthepresenceofwater.Emulsionstendtocorrodefuelinjectionsystemcomponentsandcauseelastomercompatibilityproblems.Sincethevolumetricheatingvalueofemulsionsisreducedrelativetodieselfuel,adjustmentstoincreasefuelflowmaybenecessarytomaintainfullpower.

Forthesereasons,noemulsionsofmethanolanddieselfuelhavebeencommercializedtodate.

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c. USe of MethAnol throUGh fUMiGAtion

Fumigationisamethodtointroducealcoholintoadieselenginebycarburetionorvaporizationintheintakemanifoldwithsubsequentignitionbydieselfuelinjection.Thisrequiresadditionofacarburetor,fuelinjectionsystem,orvaporizeralongwithaseparatefueltank,lines,andcontrolsforthemethanol.Methanoldeliverymustbelimitedatallloadstopreventmisfireandatintermediateandhighloadstopreventengineknock.Inthemidloadrange,upto50%ofthefuelenergycanbederivedfrommethanol,whileatlowerengineloads,upto80%dieselfuelenergysubstitutionhasbeendemonstrated[63].Thetypicaloverallreplacementvaluehasbeenmuchlower,however.Thecontrolrequirementofanenginetoachieveitsmaximumdieselfueldisplacementvalueincreasesthecomplexityoftheenginecontrolsystem.Anadvantageofafumigationsystemisthatswitchingfromfumigationtostraightdieselfueloperationmaybepossible–clearlyadesirableoptionifmethanolsuppliesareintermittent.

Turbochargedenginespresentdifficultiesformethanolfumigation.Ingeneral,itiseasiertointroducethemethanolbeforetheturbocharger,butmethanolisdifficulttovaporizetotallybecauseofitshighlatentheat,andliquidimpingementonthecompressorwheelwillcausedamagerapidly.Introductionofthemethanoldownstreamofthecompressoralleviatesthisproblembutmakesinstallationmoredifficult.

Overall,fumigationisbestsuitedtoretrofitapplicationswhereitcanhavebeneficialeffectsonemissions[70].

d. USe of MethAnol in dUAl injection enGineS

Indualinjectionengines,asecondinjectionsystemisaddedjustformethanol.Theoriginalinjectionsysteminjectsjustenoughdieselfueltoignitethemethanol.Dualinjectionenginesareveryeffectiveatusinglargeamountsofmethanol–displacementsof90%atfull-loadand50%atidleandlow-loadhavebeenachievedbynumerousresearchers[63].Enginesconfiguredthiswayhaveshownessentiallythesameefficiencyastheirdieselfuelcounterparts,withtheemissionsadvantagesofmethanol(i.e.,lowerNOxandparticulates).Dualinjectionenginesneverachievedcommercialization,nodoubtduetotheirincreasedcost(asecondfuelsystem)andtheinconvenienceofhavingtwofuelsystemsonboard.

e. USe of MethAnol With iGnition iMproVerS

Ignitionimprovers(alsoreferredtoascetaneimprovers)promiseanattractivemeanstoallowtheuseofmethanolindieselengines.Theadditionofignitionimproverstomethanolcangiveitthesameignitabilitycharacteristicsasdieselfuel.Thisallowstheuseofmethanolinunmodifieddieselengines,avoidingcomplicatedandcostlyenginemodifications(thoughthefuelinjectionsystemwillhavetobemodifiedforincreasedflowcapacityandforcompatibi1itywithmethanol).A1so,itcoulda1lowthesameenginetousemethanolanddieselfuela1ternativelyastheoperatorseesfit.

Whilenoignition-improvedmethanolhasbeenusedotherthaninfleetdemonstrations,ignition-improvedethanolhasbeenusedasafuelindieselenginesinBrazilsinceMercedes-BenzdoBrasilinitiatedatestprojectusingbusesin1979.Theinitialexperiencewasfavorableandin198322-tonand32-tonclasstruckswithenginesconvertedtouseignition-improvedethanolwereintroducedforsalebyMercedes-BenzdoBrasil.(Conversionkitsforexistingtruckswerea1somade

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availab1e.)Asof1986,about1,700trucksusingignition-improvedethanol(newandconverted)wereinoperationinBrazil[63].

Sincemostignition-improvershavenitrogenintheircomposition,concernwasexpressedthatthisnitrogenwouldcontributetoNOxemissions.ExtensivetestingshowedthatonlyasmallfractionofthisnitrogenendedupasNOxandoverall,NOxemissionsdecreasedbasedprimarilyontheemissioncharacteristicsofmethanol[63].

Overall,ignition-improvedmethanolrepresentsawaytousemethanolinexistingandnewdieselenginesalbeitwithsuitablemodificationstoaddressmaterialscompatibilityissues.Thecostoftheignitionimproverisalsoafactorinwhetherignition-improvedmethanolrepresentsaviablefuel.Inthisregard,dimethyletherhasshownpromise[71].

f. USe of MethAnol in dieSel enGineS USinG coMpreSSion iGnition

Severalresearchersdemonstratedthatdieselenginescouldachievecompressionignitionofmethanolwiththeassistanceofglowplugsor“hotspots”inthecombustionchamber.TheDetroitDieselCorporationusedthisconcepttobuildacompressionignitionversionoftheirpopular2-strokedieselenginethatwasusedinhundredsoftransitbusesintheU.S.andinotherheavy-dutyvehicleapplications[72].Thisengineachievedcompressionignitionofmethanolatlowloadsbyglowplugheating,andathighloadsbyretaininglargeamountsofburnedgaseswhichheatedtheincomingmethanolsoitwouldreachignitionundercompression.TheseengineshadverylowNOxemissionsandtheonlyparticulateemissionstheyemittedwherefromconsumedlubricatingoil.Whiletheseenginesarenolongerinuseandhavebeenreplacedbynewer-design4-strokeengines(nomethanolversions),theyillustratethecapabilitytodesignenginesforcompressionignitionofmethanol.Caterpillardevelopedamethanolversionoftheir33064-strokedieselengineusingglowplugstoachieveignition[73]andNavistardevelopedamethanolversionofitsDT-4664-strokedieselenginealsousingglowplugs[74].

Lookingforward,homogeneouschargecompressionignitionofferstheopportunitytodesignheavy-dutyenginesforcompressionignitionofmethanolwithverylowemissionsandhighefficiency[43].

November 2007Use of MeTHanol as a TRansPoRTaTIon fUel x. non-Road engInes and veHICles

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x. Non-Road Engines and Vehicles

A. SMAll enGineS

Millionsofsmallenginesareutilizeddailyinlawnmowers,chainsaws,leafblowers,etc.Mostatthesmallestendofthemarketaretwo-strokedesign,whilesomeofthelargerenginesinthiscategoryarefour-stroke.Thevastmajorityaresingle-cylinderwithsimplefuelsystemsconsistingofatank,shut-offvalveandverysimplecarburetor.Becausethiscategoryofenginesisverypricecompetitive,materialsarechosenonthebasisofcostandarenotengineeredtowithstandthesamelevelofmisusethatautomotivefuelsystemcomponentsareengineeredfor.

Thesesmallenginesaretypicallycalibratedtooperateonthe“rich”sideofstoichiometricforreasonsofstableoperation,easystarting,anddurability.Assuch,theseenginescantypicallyaccommodatefairlylargepercentagesofmethanolingasolinewithoutadverseimpactsonoperation.Intestsofasingle-cylinder(123ccdisplacement)gensetengine,itwasfoundtooperatewithoutanyadverseimpactsusing30%methanolingasoline[75].Thiswasdueprimarilytothefactthatthisenginewasstilloperatingrichofstoichiometricusing30%methanolingasolineatzeroengineload.Atfull-load,30%methanolingasolinereducedtheCOemissionsfrom8.7%downto4.8%.Similarly,HCemissionswerereducedfrom730to495ppm.NOxemissionswerenotmeasured,butattheserichstoichiometries,itislikelythattheywereverylowinallcases.Aldehydeemissionswerenotmeasured,butitwouldbeexpectedthatformaldehydeemissionswouldincreasesignificantlyfromthecombustionofmethanol.

TheEngineManufacturersAssociation(EMA)representstheinterestsofsmallenginemanufacturers.Whilemostdonotaddressuseofmethanol,individualmanufacturerguidelinesforusingethanolblendsprovidesomeinsight.Whilesomesmallenginemanufacturersacceptuseofethanolblends,theyrecommendthatthefuelnotbeallowedtostayinthefuelsystemwhiletheengineisnotbeingused.Thisispresumablybecausetheirfuelsystemsarenotcompatiblewithethanolunderconditionsofconstantexposure.Deteriorationofplasticpartssuchaslinesandtanksareprobable,asiscorrosionofthefuelsystemandevenofinternalengineparts–thecrankcaseoftwo-strokeengines,forexample.Corrosioninhibitorshavebeenfoundtobesuccessfulinreducingthecorrosionof2-strokeenginematerialsandwouldhavetobeintroducedasacomponentofthefuel[76].

B. lArGe enGineS

Largenon-roadenginesaretypicallyderivedfromtransportationengines,thoughsomearepurpose-built.Acharacteristictheyallhaveincommonisasimplefuelsystemandnoemissioncontrolsystem(thoughthisischangingintheU.S.,whichisimplementingemissionstandardsfornon-roadengines.)Largenon-roadenginestypicallyarenotset-uptooperateasrichlyastheirsmallercounterparts.Consequently,addingmethanoltotheirfuelwillbenoticedmorereadilyintermsofmoredifficultcold-starts,degradedtransientresponsetorapidthrottlechangesandreducedmaximumpoweroutput.Cloggedfuelfiltersarelikelysoonafterintroductionofmethanolblendssincethemethanolwillremoveanyresiduethathasbuiltupinthefuelsystemovertime.

Changesinemissionsfortheseenginesusingmethanolblendsshouldbesimilartothoseforsmallengines:significantlyreducedCOandHCs,andslightincreasesinNOx.Sincetheseengines

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rarelyhavecatalysts,methanolblendswouldbeexpectedtoincreaseemissionsofformaldehyde,whilehydrocarbontoxicswouldbeexpectedtodecrease,asexplainedinSectionVII.

Usingmethanolblendsinlargenon-roadenginesislikelytocausecorrosionofthefuelsystemcomponentsandincreasedwearoftheengineunlessoilchangesaremademorefrequently.Manyoftheseenginesusecarburetors,whicharemadeofmetalsthatwillcorrode,andhavemanyelastomericandplasticpartsthatwillbedegradedbymethanol.Fuellinesarelikelytoswellandsoften,leadingtoleaksastheydeteriorate.Filterelementstendtoseparatesincetheglueusedinmanufacturehasbeenshowntodissolvewhenexposedtomethanol.

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Appendix A. Properties and Characteristics of Importance for Fuel Specifications

Mostorallmethanolplantsintheworldtodayhavebeendesignedtoproducemethanoltoexactingchemicalgradestandards.Alessstringent“CommercialGradeMethanol”specificationhasalsobeenusedwhereahighlevelofchemicalpurityhasnotbeenrequired.Methanolbelowchemicalgradecanresultfromrunningachemicalmethanolplantbelowdesignstandardsforpurity,fromcontaminationinstorageandtransport,orfromotherprocesses,suchasrecyclingmethanolusedinachemicalprocess,suchasintheproductionofdimethylterephthalate.

Withrenewedinterestinusingmethanolasafuelforinternalcombustionengineandfuelcellvehiclesand/orasablendingcomponentforgasoline,therecouldbeaneedtoconsidertheadoptionofstandardsforsuchusebasedonthepropertiesofmethanolanditseffectonthepropertiesoftheblendedfuels.Suchstandardscouldtakeanumberofforms,includingstandardsforthemethanolitself,standardsformethanol/cosolventmixtures,and/orstandardsforthefinalblendedfuels.Someoftheparametersthatshouldbeconsideredforinclusioninsuchstandardswouldapplytobothneatmethanolfueluse(e.g.M100and/orM85)andlowlevelmethanolblends(e.g.5-10%,includingcosolvents),whileotherparameterswouldprobablybedifferentforhighlevelvs.lowlevelblends.Someofthefuelmethanolparameterscouldinvolvelesspuritythanchemicalgradestandards,butconcernsrelatedtofuelusecouldsuggesttheneedforadditionalparametersnotrelevantwiththeultra-purechemicalstandards.

TheASTMintheU.S.hasdevelopedandmaintainedaspecificationforM85foruseinFFVs[77].CaliforniadevelopedanM85specificationguideline[78]thoughithasbeensupersededbytheASTMspecification.Californiaalsodevelopedaneatmethanolspecificationguidelineformethanolusedinheavy-dutyvehiclesorforblendingofothernear-neatmethanolfuels[79].ThesespecificationsandguidelinesrepresenttheaccumulatedexperienceofusingmethanolasavehiclefuelintheU.S.Thefollowingnarrativeprovidesinsightintotheimportanceofthecomponentsofvariousfuelpropertiesandcharacteristicsthatareaddressedbythespecifications.

A. propertieS of concern for loW leVel MethAnol BlendS

Water ToleranceMethanolhasaveryhighmiscibilitywithwater,whilebothmethanolandwaterhavea

fairlylowsolubilitywithmanyofthehydrocarbonsconstitutinggasoline.Thesolubilityofbothmethanolandwateringasolinedependsonthecompositionofthegasoline,witharomaticshavingthehighestmutualsolubility,followedbyolefins.Therefore,methanolissusceptibletocarrywatercontaminationintogasolineandtoattractadditionalwateronceinavehicle’stank.Withaccumulationofwaterorsignificanttemperaturedrops,thefuelblendispronetoseparateintodistinctphaseswithdistinctwater/methanolandgasolinephases.Ifthisoccursinthetank,theaqueousphasewillfalltothebottom,buttheseparationcouldoccuratotherpointsinthefuelsystemandcouldpotentiallycauseavarietyofproblemsincludingfailuretostartbecausetheengineisstarvedofthevolatilehydrocarbons,knockingbecausethegasolinehaslosttheoctaneofthemethanol(andpossiblyofaromaticspartiallyseparating),filterplugging,andcorrosion,amongothers.

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Avoidanceofphaseseparationandwater-associatedproblemsinvolvesnumerousprecautionsinmarketinganddistributionofmethanolblends.Withregardtofuelcomposition,watertolerancecanbeaddressed(beyondlimitsonthemethanolcontent)throughacombinationofuseofcosolvents(usuallyhigheralcohols),formulationofthegasolineblendstock,andlimitsonwatercontentofthemethanoland/orblendedfuel,suchasatpointofsale.Unfortunately,formulatingtheblendstockforhighwatertolerancegenerallyworksagainstformulatingforemissionscontrol.

ASTMD4814,theU.S.StandardSpecificationforAutomotiveSparkIgnitionFuel,includesaspecificationforwatertolerance,withmaximumphaseseparationtemperatureprovidedforspecificregionsmonth-by-month.Unfortunately,thetestprocedureforthestandard,D6422,hasapparentlyshownpoorrepeatability,andthephaseseparationstandardofD4814maybeeliminatedintheabsenceofareliabletestmethod.Intheabsenceofsuchastandard,alimitonthewatercontentofthemethanolandblendedfuel,alongwithpossiblecosolventrequirements,maybetheonlyavailablecontrolparameters.Specificgravitymightalsobeusedasaproxyforwatercontentofthemethanolbutwillnotindicatethewatertoleranceoftheblendedfuel.

Volatility/DistillationVolatilitypropertiesofgasolines,includinggasoline/alcoholblends,areimportanttoavoid

bothproblemsincold-starting(inadequatevolatility)anddrivabilityproblemssuchasvaporlock,aswellasexcessevaporativeemissions(excessvolatility).Volatilityparameterstypicallyincludevapor/liquidratio,vaporpressure,anddistillationmeasuressuchasrelationshipsbetweentemperaturesandpercentsevaporated.Blendingmethanolwithgasolineatlowlevelstypicallybooststhevaporpressureandcreatesabulgeor“knee”inthedistillationcurve,whichcanbereducedwithuseofcosolvents,butblendstocksmayneedtobespeciallydesignedtoprovideacceptablevolatilitycharacteristics.Merelyreducinglightendstocompensateforthefrontendvolatilityboostmayresultinstartingproblemsandotherdrivabilitydegradation.

CarbonylsCarbonylsareoftenpresentasby-productsofmethanol/higheralcoholproductionand

representtoxicityconcernsinhighconcentrations.

AcetoneConcernshavebeenexpressedregardingacetone,includingconcernsoveruncontrolled

combustionandpossibledamagetovehicles.The“CommercialGrade”methanolspecificationsusedinEPAwaiversalsoincludedanacetonelimit,thoughthatmaynothavederiveddirectlyfromfuelconcernsorexperience.

AcidityLowmolecularweightacidscanbeverycorrosivetometals,particularlyinaqueoussolutions,

whichcouldresultfrommethanol’shighwatermiscibility.Onewayofcontrollingthemwouldbealimitonweightpercentofaceticacid.

AlkalinityExcessalkalinitycouldreflectanexcessofammonia,whichcouldalsobecorrosiveorhave

undesirablecombustionproperties,possiblycontrolledthroughweightpercent.

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pHeLevelsofpHebelow6.5infuelmethanolcanresultinformationoffilmorexcessivewearof

certainengineparts,whilepHelevelsabove9.0canadverselyimpactplasticpumpparts.

NonvolatilesNonvolatilescouldbepresentfromvarioussourcesandcouldresultincloggingoffueland

enginecomponentsorcouldcauseincreasesinexhaustemissionsthroughincompletecombustion.

CopperCopperisknowntobeacatalystoflowtemperatureoxidationofhydrocarbonsandto

contributetoformationofgumsandpolymers.

Corrosion/ConductivityCorrosionisaconcerngenerallyforalcohol/gasolineblends,includingpossiblecorrosionfrom

thealcohols,fromwatercarriedbythealcohols,orfromexcessacidityorammonia.Whiletestmethodsdonotexistforallmetalsusedinvehiclesystems,afewdoexistandshouldbeconsidered,amongthemcopperstripcorrosionandtheNACERustTestadoptedbytheNationalAssociationofCorrosionEngineers.Conductivitycanalsobeusedasanindicatoroftotalions,whichwillserveasacontrolonioniccorrosivity.

AshAshismorelikelytobepresentfromcosolventalcoholsthanfromthemethanolitselfbut

couldalsobeaconcernandshouldbeconsidered.

GumPresenceofgumsinfuelcancauseformationofdepositsthatcouldimpedethefunctioningof

movingpartswithinenginesandfuelsystems,aswellasplugfilters,etc.Alcoholshavebeenknowntodissolvegumsinstorageandtransportvessels,carryingthemintovehiclefuelsystems.Althoughthealcoholsarenotthemselveslikelytoformgums,impuritiesinthealcohols,suchascopper,cancontributetogumformation.Testproceduresexistforpresenceofgums,bothas“existentgums”andas“solventwashedgum,”i.e.,gumpresentafteraheptanewashofthefuel.

SulfurSulfurreducestheeffectivenessofemissionscontrolsystemsandcausesthemtodegrademore

rapidly.Inaddition,itcancauseengineoiltodegrademorerapidlyandcorrodeengineparts.TheU.S.andEuropehaveadoptedstrictlimitsonthesulfurcontentofgasoline,andmethanoladditionshouldnotbeallowedtocausethestandardtobeexceeded.

SulfatesSulfates,particularlyinorganicsulfates,havebeenbelievedtocausedepositsbothinfuel

dispensingpumpsandinvehiclefuelinjectors,withthelatterresultinginenginemisfiringandpoordriveability.Sulfateionsarealsoofconcerninregardtoelectrolyticcorrosion.Considerationshouldbegiventoincludingeitheratotalsulfatespecification,inorganicsulfatespecification,orboth.

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Chlorides/ChlorineLowconcentrationsofchlorideionscanbecorrosivetometals.Atestprocedureexistsfor

chlorideion.Chloridesandchlorinegenerallyarealsoofconcernrelatingtocorrosion,formationofdioxinsincombustion,andotherpossibletoxiccombustionproducts,sothatatotalchlorideoraninorganicchlorinetestmightalsobeconsidered.

Purity and AppearanceStandardscanspecifypurityandappearancecharacteristicsasgeneralprecautionsagainst

otherconcernsnotspecificallyidentified.

B. propertieS of concern for hiGh leVel MethAnol fUelS (e.G., M85)

MostoftheparametersofconcernandpossibletypesofspecificationsindicatedabovewillalsobeapplicabletoneatmethanolandM85,sometoagreaterdegreeandsometoalesserdegree.Therearesomedifferences,however,asdescribedbelow.

Volatility/DistillationUnlikewithlowlevelmethanolblends,theprimaryvolatilityconcernwithhighlevelmethanol

fuelsisinadequatevaporpressureforcold-starting,particularlyinlowambienttemperatures.RVPhastraditionallybeenusedtoassurestartingwithhydrocarbonfuelsbuthassometimesbeenfoundinadequateforM85.Althoughthereisnogenerallyacceptedspecification,GeneralMotorsCorporationhasproposeda“ColdStartingPerformanceIndex”thatcorrelatesbetterwithstartingthanRVPdoes.VolatilityanddistillationparametersforM85fuels,aswithlowerlevelblends,aredeterminedprimarilybythecompositionofthehydrocarbonfractionofthefuel.Fordriveabilitygenerally(beyondstartingconcerns),thesamedistillationspecificationsthatapplytoothersparkenginefuelscanbeusedforM85.

Flame LuminosityMethanolburnswithaflamethatisnearlyinvisibleindirectsunlight,whichraisessafety

concernsiffiresweretooccurandgounnoticed.Flameluminositycanbeprovidedbydesignofthehydrocarbonportionofthefuel,withhigherconcentrationsofaromatics,particularlycertainaromatics,providinggreaterluminosity.Considerationshouldbegivenforincludingaflameluminosityspecification.

LubricityMethanolprovideslesslubricitythanhydrocarbonfuels,whichcanresultinincreasedwear

onvariousenginefuelsystemcomponentswithveryhighlevelblends.Lubricityadditivesareonemeansofaddressingthis.Eitherafuellubricitystandardorarequirementforadditivesmeetinganadditivestandardcouldbeused.

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References

1.“BeyondOilandGas:TheMethanolEconomy,”byGeorgeA.Olah,AlainGoeppert,andG.K.SuryaPrakash,Copyright2006,WILEY-VCH,ISBN3-527-31275-7.

2.U.S.DepartmentofEnergy,EnergyInformationAdministration,http://www.eia.doe.gov/cneaf/alternate/page/datatables/aft1-13_03.html

3.“CompendiumofSignificantEventsintheRecentDevelopmentofAlcoholFuelsintheUnitedStates,”byR.L.Bechtold,1987,OakRidgeNationalLaboratoryreportnumberORNL/Sub/85-22007/1.

4.GeneralMotorsCorporationSubmissionatthePublicHearingontheGasohol,MethylT-ButylEther,andArconol211(f)WaiverRequests,September6-8,1978,EPADocketMSED-211(f)-MTBE-4.

5.“FuelsandFuelAdditives:Gasohol;Marketability,”44Fed. Reg.20777,April6,1979.

6.“Fuels;BlendsofEthanolinUnleadedGasoline,”47Fed. Reg.14596,April5,1982.

7.“WaiverApplicationbyAtlanticRichfieldCo.,DecisionoftheAdministrator,”44Fed. Reg. 10530,Feb.21,1979.

8.ApplicationforMethylTertiaryButylEther,DecisionoftheAdministrator,”44Fed. Reg.12242,March6,1979.

9. “ApprovalofaProprietaryFuelAdditive,”44Fed. Reg.37074,June25,1979.Thecompositionoftheadditivewasdisclosedonlyafterapprovalofthewaiver,“FuelsandFuelAdditives,”45Fed. Reg.9796,February13,1980,leadingtoapetitiontorevokethewaiver,whichEPAdenied,“FuelsandFuelAdditiveWaivers,DenialofaPetitiontoRevokeaWaiver,”45Fed. Reg.75755,November17,1980.

10.“FuelsandFuelAdditives,DefinitionofSubstantiallySimilar,”45Fed. Reg.67443,October10,1980.

11.“FuelsandFuelAdditives,RevisedDefinitionof‘SubstantiallySimilar’,”46Fed. Reg.38582,July28,1981.

12.Ibid.at38584.

13.46Fed. Reg.56361,Nov.16,1981.

14.50Fed. Reg.2615,Jan.17,1985.

15.53Fed. Reg.3636,Feb.8,1988,corrected53Fed. Reg.17977,May19,1988,revised53Fed. Reg.43768,October28,1988.

16.53Fed. Reg.33846,September1,1988.

17.56Fed. Reg.5352,February11,1991.

18.45Fed. Reg.26122,April17,1980.Seealso,45Fed. Reg.32761,May19,1980.

19.45Fed. Reg.53861,August13,1980.

20.45Fed. Reg.47725,July16,1980.

21.46Fed. Reg.48975,October5,1981.

22.49Fed. Reg.11879,March28,1984.

23.American Methyl Corporation v. EPA,749F.2d826(D.C.Circuit,1984).

24.MotorVehicleManufacturers’AssociationoftheUnitedStatesv.EPA,768F.2d385(D.C.Circuit,1985).

25.51Fed. Reg.9114,March17,1986.

26.48Fed. Reg.52634,November21,1983.

27.53Fed. Reg.2088,January26,1988.

28.See,e.g.,EPAFinalRule,“EmissionsStandardsforCleanFuelVehiclesandEngines,RequirementsforClean-FuelVehicleConversions,andCaliforniaPilotTestProgram,”59Fed. Reg.50042,September30,1994.29.“AlcoholsandAlcoholBlendsasMotorFuels,StateoftheArtReport,” InternationalEnergyAgency,Informationno.580-1986,preparedbyTheSwedishMotorFuelTechnologyCo.(SDAB),p.6:3.

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30.“TheMethanolStory:ASustainableFuelfortheFuture,”byRobertaJ.Nichols,JournalofScientific&IndustrialResearch,Vol.62,January-February2003,pp.97-105.

31.“ThePhysicalPropertiesofGasoline/AlcoholAutomotiveFuels,”byFrankCox,U.S.DepartmentofEnergy,ProceedingsoftheAlcoholFuelsTechnologyThirdInternationalSymposium,Vol.II,May28-31,1979.

32.“AlcoholsandEthers–aTechnicalAssessmentofTheirApplicationasFuelsandFuelComponents,”APIPublication4261,SecondEdition,July1988,AmericanPetroleumInstitute,1220LStreet,Northwest,Washington,D.C.20005.

33.“StatusofAlcoholFuelsUtilizationTechnologyforHighwayTransportation:A1981Perspective–VolumeI–Spark-IgnitionEngines,”May1982,U.S.DepartmentofEnergyreportDOE/CE/56061-7.

34.“MethanolGasolineBlendsinNorway,”B.Rolfsen,TheNorwegianMethanolGroup,andJ.Bang,TheNationalInstituteofTechnology,Oslo,Norway,proceedingsoftheFifthInternationalAlcoholFuelTechnologySymposium,May13-18.1982,Auckland,NewZealand.

35.“OperatingaVehicleFleetonMethanolBlendFuels–1978to1981,”byT.W.Shears,MinistryofWorksandDevelopment,Auckland,NewZealand,andB.T.Judd,DepartmentofScientificandIndustrialResearch,Wellington,NewZealand,proceedingsoftheFifthInternationalAlcoholFuelTechnologySymposium,May13-18.1982,Auckland,NewZealand.

36.Keller,J.1.,etal.(UnionOilCompanyofCalifornia),“MethanolFuelModificationforHighwayVehicleUse-FinalReport,”U.S.DepartmentofEnergy,publishedasNTISdocumentNCP/W3683-18,July,1978.

37.“AStudyofMethanol-GasolineCorrosivityandItsAnticorrosiveAgent,”byZhizhongLiu,ShihaiXu,andBenzhangDeng,TheLogisticalEngineeringInstitute,Chongqing,China,proceedingsoftheTenthInternationalSymposiumonAlcoholFuels,November7-10,1993,ColoradoSprings,Colorado,USA.

38.“LaboratoryStudiesoftheEffectsofMethanolFuelonEngineOilandMaterials,”byShirleySchwartz,GeneralMotorsResearchLaboratories,Warren,MI,USA,proceedingsoftheVIInternationalSymposiumonAlcoholFuelsTechnology,Vol.I,May21-25,1984,Ottawa,Canada.

39.“BrazilianVehicleCalibrationforEthanolFuels,”G.K.Chui,R.D.Anderson,R.E.Baker,FordEngineeringandResearchStaff,USA,andF.B.P.Pinto,FordofBrazil,ProceedingsoftheAlcoholFuelsTechnologyThirdInternationalSymposium,Vol.II,May28-31,1979.

40.Pefley,R.K.,etal.(UniversityofSantaClara,SantaClara,California),CharacterizationandResearchInvestigationofAlcoholFuelsinAutomobileEngines-FinalReport,U.S.DepartmentofEnergy,ContractNo.DE-AC03-78CS,December,1980.

41.“FleetTestonSantanaMethanolCarsinChina,”K.Pan,H.Zhai,R.Xie,Y.Yan,J.Zhu,R.Zhang,andR.Zhao,ChineseAcademyofSciences,Beijung,China,S.Han,StateScienceandTechnologyCommissionofChina,Beijing,China,G.DeckerandD.Steinke,VolkswagenAG,Germany,proceedingsoftheoftheIXInternationalSymposiumonAlcoholFuels,Firenze,Italy,November12-15,1991.

42.Menrad,H.,W.Lee,andW.Bernhardt(VolkswagenwerkAG),“DevelopmentofaPureMethanolFuelCar,”SocietyofAutomotiveEngineers(SAE)paper770790,September,1977.

43.“InvestigationoftheEffectsofInjectionTimingonThermo-AtmosphereCombustionofMethanol,”byMingfaYao,ZhengChen,andZun-qingZheng–StateKeyLaboratoryofTianjinUniversity,andQuanchangZhang,MechanicalEngineeringSchool,GhaugxiUniversity,SAEPaper2007-01-0197.

44.AtlanticRichfieldCompanyWaiverApplicationtotheU.S.EnvironmentalProtectionAgency,April17,1981.

45.“PerformanceEvaluationofAlcohol-GasolineBlendsin1980ModelAutomobilesPhaseII–Methanol-GasolineBlends,”theCoordinatingResearchCouncil,Atlanta,Georgia,fortheU.S.DepartmentofEnergy,January1984,DOEreportno.DOE/CS/50003-1.

46.“InvestigationintotheVehicleExhaustEmissionsofHighPercentageEthanolBlends,”byDavidGuerrieri,PeterCaffrey,andVenkateshRao,U.S.EnvironmentalProtectionAgency,SAEPaperNo.950777.

47.“MarketBarrierstotheUptakeofBiofuelsStudy-ATestingBasedAssessmenttoDetermineImpactsofa20%EthanolGasolineFuelBlendontheAustralianPassengerVehicleFleet,”March2003,TheOrbitalEngineCompany.

November 2007Use of MeTHanol as a TRansPoRTaTIon fUel RefeRenCes

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48.“MarketBarrierstotheUptakeofBiofuelsStudyTestingGasolineContaining20%Ethanol(E20)-Phase2BFinalReporttotheDepartmentoftheEnvironmentandHeritage,”May2004,OrbitalEngineCompany.

49.http://www.transportation.anl.gov/software/GREET/index.html

50.Bechtold,R.L.(U.S.DepartmentofEnergy)andJ.B.Pullman(UniversityofSantaClara),“DrivingCycleFuelEconomy,EmissionsandPhotochemicalReactivityUsingAlcoholFuelsandGasoline,”SAEPaper800260,February1980.

51.Auto/OilAirQualityImprovementResearchProgramTechnicalBulletinNo.10,“EmissionsofThreeDedicated-MethanolVehicles,”June1992.

52.U.S.EnvironmentalProtectionAgencydecisiononDuPontdeNemoursandCo.July11,1984waiverapplicationformethanol/gasolineblends.

53.ControlofAirPollutionFromNewandIn-UseMotorVehiclesandNewandIn-UseMotorVehicleEngines;TechnicalAmendmentstotheTestProceduresforMethanol-FueledMotorVehiclesandMotorVehicleEnginesandPetroleum-FueledMotorVehicles;FinalRule,FederalRegister:June30,1995{Volume60,Number126)],[RulesandRegulations],[Page34325-34377].

54.“FuelPermeationFromAutomotiveSystems:E0,E6,E10,E20ANDE85-FinalReport,”December,2006,CoordinatingResearchCouncil,Inc.,3650MansellRoad,Suite140,Alpharetta,GA30022.

55.“CarbonSequestration–TechnologyRoadmapandProgramPlan”U.S.DepartmentofEnergy,OfficeofFossilEnergy,http://www.netl.doe.gov/publications/carbon_seq/2005_roadmap_for_web.pdf.

56.“AnInvestigationoftheFeasibilityofCoal-BasedMethanolforApplicationinTransportationFuelCellSystems,”UniversityofFloridaGainesville,Florida,April2004.

57.“Methanol–Properties,Uses,Storage,Handling,”E.IduPontdeNemours&Co.(Inc.),Wilmington,Delaware19898(undatedpamphlet).

58.“TheTransportofMethanolbyPipeline,”TheU.S.DepartmentofTransportation,MaterialsTransportationBureau,ResearchandSpecialProgramAdministration,400SeventhStreet,S.W.,Washington,D.C.,20590,April1985.

59.“AlternativeFuelsGuidebook–Properties,Storage,Dispensing,andVehicleFacilityModifications,”byRichardL.Bechtold,SAEInternational,www.sae.org.

60.“METHANOLREFUELINGSTATIONCOSTS,”EAEngineering,Science,andTechnology,Inc.8401ColesvilleRd.,Suite500,SilverSpring,MD20910,February1,1999.

61.“METHANOLINDUSTRYHAILSSTATIONOPENING,”MethanolInstitutepressrelease,Sacramento,CA,April25,2002.

62.“InnovativeRefillingSolutions,”IDENTICAB,Box143,SE-18623,Vallentuna,Sweden.

63.“StatusofAlcoholFuelsUtilizationTechnologyforHighwayTransportation:A1986Perspective;VolumeII–CompressionIgnitionEngines,”byR.L.Bechtold,MuellerAssociatesfortheOakRidgeNationalLaboratory,ReportORNL/Sub/85-22007/3,January1988.

64.“AlternativeFuelsforHeavyDutyEngines:StatusofFleetTrials,”Sypher-MuellerInternational,Inc.,Ottawa(Ontario),DepartmentofEnergyReportDOE/CE/50182-T2,Nov1990.

65.ElectronicAttachmentNo.2,IEAAMFAnnualReport2006.

66.“AlternativeFuelTransitBuses-FinalResultsfromtheNationalRenewableEnergyLaboratory(NREL)VehicleEvaluationProgram,”byRobertMotta,PaulNorton,andKennethKelly,NREL;KevinChandler,Battelle;LeonSchumacher,UniversityofMissouri;NigelClark,WestVirginiaUniversity;October1996,http://www.afdc.doe.gov.

67.“CaliforniaAlternativeFueledTruckDemonstrationProgram,”byD.D.LowellandM.D.Jackson,AcurexCorporationandCindySullivan,CaliforniaEnergyCommission,WindsorWorkshoponAlternativeFuels,June13,1990.

68.“ALCOHOLS/ETHERSASOXYGENATESINDIESELFUEL:PROPERTIESOFBLENDEDFUELSANDEVALUATIONOFPRACTICALEXPERIENCES-IEAADVANCEDMOTORFUELSANNEXXXVIFINALREPORT,”byTECTransEnergyConsultingLtd,IEAReportTEC3/2005.

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69.“High-AlcoholMicroemulsionFuelPerformanceinaDieselEngine,”byB.H.West,A.L.Compere,andW.L.Griffith,OakRidgeNationalLaboratory,SAEPaper902101.

70.“OptimizingControlofNoDxandSmokeEmissionsFromDIEngineWithEGRandMethanolFumigation,”byMatsuoOdaka,NoriyukiKoike,YujirouTsukamoto,andKazuyukiNarusawa-TrafficSafetyandNuisanceResearchInstitute,SAEPaper920468.

71.“DimethylEtherasaMethanolIgnitionImprover--SubstitutionRequirementsandExhaustEmissionsImpact,”byChrisJ.GreenandNealA.Cockshutt,OrtechInternational,andLionelKing,Sypher,MuellerInternationalInc.,SAEPaper902155.

72.“DevelopmentStatusoftheDetroitDieselCorporationMethanolEngine,”byStanleyP.MillerandCraigL.Savonen,DetroitDieselCorporation,SAEPaper901564.

73.“Methanol-FueledCaterpillar3406EngineExperienceinOn-HighwayTrucks,”byB.G.Richards-ResearchDept.,Caterpillar,Inc.,SAEPaper902160.

74.“ApplicationofaLowEmissionMethanolEnginetoaHeavy-DutyTruck--VehicleInstallationandOperatingExperience,”byE.H.KoorsandS.Esbrook-NavistarInternationalTransportationCorp.,andB.Bartunek-FEVMotorentechnikGmbH&Co.,SAEPaper912661.

75.“BehaviorofaSmallFour-StrokeEngineUsingasFuelMethanol–GasolineMixtures,”byCharalamposI.Arapatsakos,AnastasiosN.KarkanisandPanagiotisD.Sparis,DemocritusUniversityofThrace-Greece,SAEPaper2003-32-0024,September,2003.

76.“StudiesonCorrosionanditsControlofTwoStrokeEngineMetalComponentsinMethanol,”byA.Jayaraman,MukeshGuptaandSudhirSinghai,IndianInstituteofPetroleum,Dehradun,India,proceedingsoftheIXInternationalSymposiumonAlcoholFuels,Firenze,Italy,November12–15,1991.

77.“StandardSpecificationforFuelMethanol(M70-M85)forAutomotiveSpark-IgnitionEngines,”ASTMD5797–07,ASTMInternational,100BarrHarborDrive,POBoxC700,WestConshohocken,PA19428-2959,UnitedStates.

78.CaliforniaAirResourcesBoardRegulationsTitle13,CaliforniaCodeofRegulations,Section2292.2.

79.CaliforniaAirResourcesBoardRegulationsTitle13,CaliforniaCodeofRegulations,Section2292.1.

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