Ex-situ up-conversion of biomass pyrolysis bio-oil vapors

Ex-situup-conversionofbiomasspyrolysisbio-oilvaporsusingPt/Al2O31

nanostructuredcatalystsynergisticallyheatedwithsteelballsviainduction2

3

MohammadAbu-Laban1,PranjaliD.Muley1,DanielJ.Hayes1,andDorinBoldor1.*4

1DepartmentofBiological&AgriculturalEngineering,LouisianaStateUniversityAgricultural5

CenterandA&MCollege,BatonRouge,Louisiana70803,UnitedStatesofAmerica6

7*Correspondingauthor.Emailaddress:[email protected]

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ABSTRACT1

Radiofrequency-drivenhydrodeoxygenationofsawdustpyrolysisvaporandthecoking2

performanceofthecatalystswereinvestigatedusingPt/Al2O3commercialpelletsmixedwith3

steelballsinsideanaluminatube.Theradio-frequencyinductionheatingofthecatalystbed4

wascomparedwithaconventionalmethodofheatingusingelectrictapeengulfingthecatalyst5

bedreactor.Partialdeoxygenationoftheoilwassuccessfullyachievedinthecatalytic6

upgradingofpyrolysisoilat234°C,withtheuseoftheinductionheater.ThemolarO/Cratioof7

theoildecreasedfrom1.36to0.51.Nodeoxygenationoftheoilwasobservedusingtheelectric8

tapecontrolunderidenticalconditionsasbothcarbonandoxygenappearedtoberemovedat9

approximatelyequalrates,withthecarbonbeingdepositedintheformofcokeontothe10

catalystinsteadofbeingrecoveredintheliquid.11

12

KEYWORDS13

InductionHeating14

Hydrodeoxygenation15

Pyrolysis16

Coking17

Steelballs18

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21

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3

1.Introduction1

Researchintobiofuelsasanalternativeenergysourcetocrudeoilhasdrawnmuch2

attentionandsuccesswasachievedfortheup-conversionofbio-oilderivedfromlignocellulosic3

biomasswiththeuseofcatalytichydrodeoxygenation(HDO)[1-4].Oneofthemostwidelyused4

methodsforthethermochemicaldecompositionofpinesawdusttoproducebio-oilisfast5

pyrolysis,intheabsenceofoxygen.Rawbio-oilpossessesarelativelysmallheatingvalue,due6

mainlytoitshighlyoxygenatedorganic,mostlyphenolic,compoundsthatmakeupasignificant7

amountofitschemicalcomposition.Watercompositionoftheliquidproductfrompine8

pyrolysisisreportedatanaverage17%byweight,whileaverageoxygencontentoftheorganic9

phaseisreportedat47wt.%[5].Thehigherheatingvalue(HHV)ofwoodpyrolysisoilaverages10

around16-19MJ/kgcomparedtoheavyfuelderivedfrompetroleumwhichisreportedat11

40MJ/kg[6].Inadditiontolowcalorificvalues,thehighoxygencontentmakesthebio-oilnon-12

idealforstorageduetoitsreactivity.Thisvolatilityinthechemicalmakeupofthepyrolysisbio-13

oilrendersitsutilizationasachemicalfeedstockdifficultduetothevariabilityinthephysical14

andchemicalproperties.15

Asmentionedabove,up-conversionofthebio-oiltoreduceoxygencontentand16

respectivelytoincreasetheenergydensityandqualityofthebio-oilcanbeachievedvia17

catalyticdeoxygenation.Inthisprocess,throughaseriesofhydrogenation,deoxygenationand18

dehydrationreactions,thecarbonylgroupsarehydrolyzedandremovedtoproducewaterand19

reducetheoxygencontentintheorganicoilphase.Inthestudyreportedin[4],m-cresolwas20

usedasabio-oilmodelcompoundtostudyitsdeoxygenationoverPt/γ-Al2O3catalystsunder21

lowpressurehydrogengas.Themainproductsofthehydrodeoxygenationreactionwere22

4

reportedtobetoluene,benzeneandmethylcyclohexane.Whilehighpressurehydrogenisalso1

usedintheHDOprocessesforcokeremoval[2,7],thehighamountofhydrogenunutilized2

makesalow-pressurehydrogensourcemoredesirable.SelectionofPtintheproposedstudyas3

themostselectivereducingmetaltowardbenzeneformation,aswellasoflow-pressure4

hydrogenwerethusbasedonexistingliteraturedata[8-13].5

In[3],thecatalyticdeoxygenationofpyrolysisoilderivedfromLeucaenaleu-cocephala6

andotherwoodspecies,includingpinesawdust,wasalsostudiedusingPt/Al2O3catalysts.The7

studyreportsadecreaseinthemolarO/Cratiofrom0.4to0.16afterdeoxygenation.Inthe8

reportedcase,theliquidoilwasfirstgeneratedandthenmixedwiththecatalystinaheated9

continuousstirred-tankreactor(CSTR),whereasinthestudyreportedhere,thecatalysis10

occurredex-situimmediatelyafterthepyrolysisreaction,whilethebio-oilwasstillinvapor11

form.12

Intheproposedstudywelookatauniquemethodofheatingthecatalystusing13

radiofrequencyinductiveheating,amethodalsoappliedtothebiomasspyrolysisprocess,as14

discussedinpreviousreports[14,15].Withtheinsightgainedfromthesereportsintooptimal15

reactorresidencetimes,biomasspyrolysistemperatureandyields,thecurrentstudybuildson16

thatinformationtoupgradethequalityoftheoilbypassingthevaporsthroughacatalystbed17

composedofasteel-Pt/Al2O3-mixforhydrodeoxygenation,asopposedtoaregularHZSM-5as18

reportedin[15]([14]didnotreportanyupgradingoftheproducedbio-oil).Inthiswork,19

inductiveheatingofthesteelballswasemployedtomaintainthebedtemperatureinan20

electricallynon-conductivealuminareactor,whereastheworkreportedin[15]usedasteel21

reactor,whichindirectlyheatsthecatalyst.Directheatingofthemixtureofcatalystanda22

5

metallicsusceptorusingRF-basedinductionensuresthatthecatalystactsasaheatsourceas1

opposedtoheatsinkobservedforconventionalheatingtechniques,anddiscouragesthe2

coolingandcondensationofpyrolysisvaporsonthesurfaceofthecatalystandsubsequent3

cokeformation.ThisopensthedoorforthedevelopmentofcatalystparticlesseededontoRF-4

receptivematerialssuchasironthatcanbeheateddirectlybyradiofrequencywavesto5

increasethetemperatureofthecatalystbed,reversingtheflowofheatfromexterior-to-6

interiortointerior-to-exterior.7

Theprincipleofaninductionheateriswellestablished,andinvolvesanalternating8

currentpassingthroughacoilwhichinducesanalternatingmagneticfieldwithinthevolume9

envelopedbythecoil.Thealternatingmagneticfieldinturninduceseddycurrentsonany10

electrically-conductiveloadplacedinthesamevolume[16].Benefitsoftheinductionheating11

includetheefficientandrapidheatingoftheload,sincetheonlyheatbeinggenerated12

originatesfromtheloaditselfwithverylittletonoheatlosstothesurrounding.More13

importantly,thepositivetemperaturegradientestablishedacrossthecatalystsurfacewould14

ideallydeterthepolycondensationandpolymerizationofthevapormolecules,preventingtar15

andcokeformation.16

Intheproposedstudy,welook,forthefirsttimetoourknowledge,attheheating17

profilesunderdifferentpowersforthecatalystbedusingstainlesssteelballsmixedwithHDO18

pelletswithinanon-conductivetubeusingthistypeofelectromagneticheating.Thenon-19

conductivetubedoesnotinteractwiththeinductionfield,andthusdoesnotcontributetothe20

heatingprocess.Onlythesteelballsand,toamuchsmallerextent,thePt/Al2O3pelletsare21

heateddirectlybytheelectromagneticfield.Componentsinpyrolysisoilcanbegintocondense22

6

attemperaturesbelow300̊C[17],dependingontheoriginatingbiomassandtheorganic1

compoundsresultingfromthespecificpyrolysisprocess.Therefore,ingeneral,itisnecessaryto2

maintainthebedtemperaturetoavoidcoolingofthepyrolysisvaporscomingfromthebiomass3

reactor.Inaddition,itisalsodesirabletosetthetemperaturecloseto,orat,thepointatwhich4

optimalreducingactivityofthecatalystoccurs,basedontheirtemperature-programmed5

reductionanddesorptionprofiles.ThehydrogenTPRandammoniaTPDresultsindicatethe6

temperatureregionsatwhichthesitesaremostreactivetohydrogenadsorption,andacidsites7

areweakandmorereactiveinthebondingofoxygenatedcompounds.Thesetemperature8

regionswouldbetheconditionsidealforthehydrodeoxygenationpathway.9

Whileseveralstudieshavelookedatthemitigationofcokeformation[18-20],thereis10

littleunderstandingoftheeffectofthesurfacecatalysttemperatureandtheroleitplaysinthe11

adsorptionofcokemolecules.Generally,adsorptionisexothermicandanincreasein12

temperatureleadstoadecreaseinadsorption.However,thecondensationofmoleculesonthe13

surfacescanalsobeduetothetemperaturegradientacrossthesurfaceofthecatalyst.A14

negativetemperaturegradientcanleadtoafasterrateofthecokeadsorption.Hence,the15

heatingmethodofthecatalystreactorcanplayasignificantroleintheformationoffouling16

compoundsonthesurfacesitesthatreducethecatalystslongevity.Byusingthenovelmethod17

ofinductiveheatingofthesteelbed,itishypothesizedthatbydirectlyheatingthecatalyst18

fromtheinteriorofthebed,therateofcondensationoftheoilvaporsandcokeformationon19

thecatalyticsitescanbesignificantlyreduced,relativetoaconventionalheatingmethod.Asa20

result,itisexpectedthattheoxygencontentofthecollectedoilisreducedfortheinductive21

7

methodasthecatalystperformanceenduresandthecarboncontentismaintainedinthevapor1

flow.2

2.MaterialsandMethods3

2.1Materials4

3.2mmPt(1wt.%)/Al2O3pelletsand99%dichloromethane(DCM)werepurchasedfrom5

Sigma-Aldrich®,one5%H2/balanceN2gascylinder(200ft3)waspurchasedfromAirLiquideand6

Type316stainlesssteelprecisionballs,7/32"diameter,werepurchasedfromMcMaster-Carr.A7

custom-madealuminaceramictubewasorderedfromSentroTech.Pineshavingsfromscrap8

wood(untreated)werecollectedfromthein-housewoodshopintheBiologicaland9

AgriculturalEngineeringDepartmentatLouisianaStateUniversityAgriculturalCenter(LSU10

AgCenter).11

2.2CatalystCharacterization12

ThePt/Al2O3pelletsweretestedasreceivedforTemperature-ProgrammedReduction,13

Desorption(TPR,TPD)andBETanalysis.AllanalyseswereperformedusinganAltamira200R-14

HPunitwiththecatalystplacedinsidea1/4”IDu-shapedquartztube.Productswereanalyzed15

withathermalconductivitydetector(TCD).16

2.2.1TemperatureProgrammedReduction[4]17

Forpre-treatment,Heliumgaswasflushedthroughat30cc/min.Thetemperaturewas18

rampedto150̊Cat10̊C/minandheldfor30minutes,andthencooledto40̊Cat10̊C/min.19

TheTPRtreatmentfollowedwiththeuseof10%H2/Argasat30cc/min,andrampedto900̊Cat20

10̊C/min.21

2.2.2TemperatureProgrammedDesorption[3]22

8

Thepelletswerefirstpre-treatedwithHeliumgasflushedat30cc/min,heatedto250̊C1

at10̊C/minandheldfor60minutes.Thebedwasthencooledto100̊Catthesamerate.To2

adsorbNH3,10%NH3/Hewasinjectedat30cc/minfor10minutes.Thiswasfollowedby3

flushingagainwithHegastodesorbtheammonia,at30cc/minandtemperaturerampingto4

900̊Cat10̊C/min.5

2.2.3BET6

A3-pointBrunauer-Emmett-Telleranalysiswasperformedaccordingtoliterature[21].7

Thecatalystwasfirstpre-treatedwithHegas,withtemperatureincreasedto150̊Cat10̊C/min8

andheldfor30min.Thequartztubewasthencooledto40̊Catthesamerate.Thecatalystwas9

thenoutgassedwithpurenitrogenat50cc/min.Datawascollectedoverthreepulseperiods10

duringwhichthebedwassubmergedinliquidnitrogenthreetimesfor300slongeach.11

2.3BiomassPyrolysisSetup12

Theexperimentalparametersforthepyrolysisofsawdustwerepreviouslydeveloped13

[14,15].Pinesawdustshavingsweregroundandfilteredto<0.5mmindiameteranddried14

overnight.Thefeed-to-catalystratiowassetafterinitiallyusingahighratiothatwas15

subsequentlyreducedinpreliminaryexperimentsuntilsignificantproductionofbenzeneand16

reductionofphenoliccompoundswasobservedfromtheGC-MSspectraoftheoilphase[14,17

15,22].Basedonthesepreliminarydata,10gofthetreatedsawdustwaspackedintothe18

centerofaninsulated310-stainlesssteeltubularreactor.Thisbiomassreactorwassuspended19

withinanRFinductioncoil(10-loop,rubber-insulatedcoppercoil,285mminlengthand59mm20

ID),connectedtoalowfrequencyinductionheater(RDOInc.,modelLFI35-100kHz).The21

biomassreactorwasconnectedtoa5%H2/bal.N2gasline,andtothecatalystbedinseries.The22

9

catalystbedconsistedof25gof1wt.%PtonAl2O3pelletsinsidea1.25”ODX0.70”ID,10”long1

99.8%aluminatubewithlowmagneticpermittivity.Thepelletsweremixedwith400gof7/32"2

diameterstainlesssteelballstofullcapacityofthetubeinordertoincreasetheloadfor3

inductiveheating.Thecatalystbedwasunderitsowninductionheater(6-loopcoil,rubber4

insulated,203mminlengthand49mmID,RDO,Inc.modelHFI135-400kHz).Thesystemwas5

purgedwith5%hydrogengasflowingat3CFHfor1hpriortothebiomasspyrolysis.Duringthis6

flushingtime,thecatalystbedwasheatedtothedesiredtargettemperatureandmaintained7

foronehourtoreduceanyoxidizedPtpriortoinitiatingpyrolysis.Thistemperaturewas8

maintainedthroughouteachindividualexperiment.Vaporsfromthebiomassreactorpassed9

throughthecatalystbedandenteredacondensationflasksubmergedinicewhichwas10

connectedtoanelectrostaticprecipitator,asdescribedin[15].Theexitstreamfromthe11

condenserleadtoethanolandwatertraps,connectedseriallytocollectanysoluble12

compounds,andthentotheoutletstream.Gassampleswerecollectedatthejunctionpriorto13

thewaterandethanoltrapsandanalyzedwithgaschromatography.14

AninfraredsensorcoupledtoanOmegaiR2CPIDcontroller(OMEGAEngineering,Inc.,15

Stamford,CT)wasusedtocontrolthetemperatureofthebiomassreactorat550̊Cbyadjusting16

thepoweroutputoftheLFIinductionheater.Thetemperatureofthecatalystbedtubewas17

manipulatedmanuallybysettingthepowerleveltoonevalueandallowingthesurface18

temperatureofthetubetoreachamaximumsteadystatevalue.Thisadjustmentwas19

performedfor3differentpowerlevels(250W,350W,and500W)toachieve3differentbed20

temperatures(234°C,286°C,and375°C).Thesurfacetemperatureofthealuminatubewas21

monitoredandrecordedinrealtimeusinganIRcamera(FLIRA325sc,FLIRSystems,Inc.,22

10

Wilsonville,OR)connectedtothermaldataacquisitionsoftware(ThermaCAMProfessional9.1,1

FLIRSystems,Inc.,Wilsonville,OR).Thetemperaturereadingsatfourdifferentpointsalongthe2

lengthofthetubewererecordedandaveragedtoobtainthetubesurfacetemperature(Figure3

1).Theemissivityvalueofthealuminatubewassetto0.9andconfirmedviatrialanderror4

usingathermocouple.5

Tocomparetheinductiveheatingmethodtoaconventionalheatingsource,an6

electricalheatingtapewasusedasourcontrolexperiment.Theelectricaltapeoperatedwith7

anon-offfeedbackcontroller.Thetemperaturesetpointwassetequaltotheinduction-heated8

runatthetemperatureinwhichtheoptimalresults,basedontheO/CandHHVvaluesoftheoil9

product,wereattained.Inaddition,abaselineexperimentwassetupandtestedinwhichthe10

pyrolysisofsawdustwascarriedoutunderidenticalconditions,butwithoutanycatalyticup-11

conversion.Allexperimentswereperformedinduplicates.12

Basedontheparametersreported[14,15],pyrolysisofthesawdustproceededfor20-13

25minforoptimumreactiontime,whichwasthetimenecessaryforthevaporstopassandthe14

charmasstostopdecreasing.Thecatalystbedwaspost-treatedbymaintainingitstemperature15

foranother30minafterthebiomasspyrolysisreactorwasturnedoff,underhydrogen/nitrogen16

flow,toallowforanydepositedoil/tartoburnoffandcatalyzefurtherbyhydrogenationand17

deoxygenation.Theresidencetimesofthevaporsweredeterminedbyadjustingthevolumetric18

flowrateexitingthebiomasspyrolysisreactortoaccountforthegasexpansionsasaresultof19

thetemperaturechangesbasedontheidealgaslaw,usingthevoidvolumeofthecatalystbed20

asaconstant.Biocharleftinsidethebiomassreactor,andliquidproductinsidethecondenser21

werecollected,quantifiedandanalyzedbyGC-MS,KF-titration,andCHNanalysis.22

11

2.4GasChromatography1

TheoilphaseoftheliquidproductwasextractedusingDCM(5:1),ofwhicha5µL2

samplewasinjectedintoaGCcolumn(VarianSaturn2200).Thecolumnovenwasheatedto3

40°Candheldfor6min,rampedto240°Cat4°C/minandheldfor10min,andthenagain4

rampedto280°Cat20°C/minandheldfor5min,foratotaltimeof73min[15].TheGCmass5

spectrapeakswereidentifiedusingthebuiltinMSlibrarysoftwareandthepeakareaswere6

integratedtodeterminetheproportionalwt.%ofeachcompoundintheorganicphase.Non-7

condensablegassampleswerecollectedforcompositionanalysisusingGC(SRI8610C,SRI8

Instruments)tomeasuretheconcentrationsofCO,CO2andCH4.Avaluableproduct,H29

releasedwasnotmeasuredduetoequipmentlimitations.10

2.5KFTitration11

TheaqueouscontentoftheliquidproductwasdeterminedusingaKFcoulometric12

titrator(KarlFischerTitratorMetrohmModel831KFCoulometer)(ASTME203-08).50µLofthe13

oilsamplewasmixedwith50mLofethanol.A0.5mLsampleofthemixturewasinjectedinto14

thecoulometertoyieldthewatercontentreadinginppm.Anethanolsamplewasalsoreadto15

accountforanywatercontributedbythehygroscopicethanol.16

2.6ElementalAnalysis17

Carbon,HydrogenandNitrogencompositionsforthebiomass,charandoilsamples18

weredeterminedusinga2400Series2CHN(PerkinElmer,Inc.)elementalanalyzerasdescribed19

in[14].Theoxygencontentwasdeterminedbytakingthedifferencebetween100%andthe20

sumofC,H,andNcontent.21

2.7HigherHeatingValue22

12

TheHHVsfortheoilphasesweredeterminedusingDulong’sformula[23],wherethe1

%CHOvaluesfromourelementalanalysiswereused.2

HHV(MJ/kg)=[338.2*%C+1442.8*(%H-%O/8)]*0.001 (Eqn.1)3

Forthecharsolids,theHHVwasdeterminedusingDemirbas’sformula[24],4

HHV(MJ/kg)=0.3856*(%C+%H)–1.6938 (Eqn.2)5

2.8StatisticalAnalysis6

Aonetailt-testwasrunwherevermentionedassumingunequalvariations,atα=0.05.7

AnANOVAanalysiswasalsorunwherementioned,againassumingunequalvariationswith8

α=0.05.Pvalueslessthanαwereruledstatisticallysignificantbetweentwoormoregroupsof9

data.10

3.Results&Discussion11

3.1CatalystAnalyses12

Thetemperature-programmedreductionanddesorptionprofilesforthePt/Al2O313

catalystpelletsareshowninFigure2.Theprofilesshowtwoprincipalpeakssuggestingtwo14

differentsiteswithdifferentadsorptionstrengths.Thefirstreductionpeakappearedataround15

167̊C,astheplatinumoxideisreducedtoitsmetallicform[25].However,thepeakataround16

356̊Cindicatesaclassofplatinumoxideexhibitingstrongerinteractionswiththesupportand,17

hence,requiringhighertemperaturetoreduce[26].18

BETanalysisonthePt/Al2O3pelletsyieldedaspecificsurfaceareaof100.24m2/g.The19

acidityofthecatalyst,determinedfromthepeakareaoftheNH3-TPDprofile(Figure2),was20

determinedtobe1.69NH3mmol/g,catalyst.21

3.2HeatingProfiles22

13

Thetemperatureprofilesforthepyrolysissetsheatedatdifferentpowersusingthe1

inductionheater,andtheonesetfortheelectricalheatingtapeareshowninFigure3.Inall2

cases,thetemperatureroseexponentiallytoamaximumvalueastheradiativeandconvective3

heatlossesbegantoequaltheheatinduced.Thecurveswerefittedtoa2-parameter4

exponentialformulaafternormalizingto25°C(Table1).5

T(°C)=a*[1-exp(-b*t(s))] (Eqn.3)6

Table1.Fittingparametersfortemperatureprofilesineachexperiment,fittedtoan7

exponentialrisetoamaximum(2parameter)formula.8Experiment a b Adj.R

2

IH250W 239 0.0009 0.987

IH350W 304 0.0008 0.990

IH500W 386 0.0011 0.989

HT300W 220 0.0017 0.975

9

ThemaximumsteadystatetemperaturesareplottedinFigure4,whichalsoshowthe10

maximumtemperatureoftheceramictubeloadedwiththecatalystpelletsonly,withoutsteel11

ballsandenvelopedwithintheinductivecoil.Asitcanbeobserved,hightemperatureswere12

unachievablewiththecatalystonly,withoutthepresenceofthesteelballsactingasaheating13

medium.Thisphenomenonismostlyduetotheveryweakinteractionofthealuminasupport14

withtheelectromagneticfield,aswellasduetothehighporosityofthecatalystswhich15

reducestheoverallmassavailableforelectromagneticinteractionanddissipationofenergyas16

heat.17

Fromthetemperatureprofilesitcanbededucedthatwithhigherpowerinthe18

inductionheatingmachine,whensteelballsarepresent,themaximumtemperatureincreased19

linearlyasmorecurrentwasinducedonthesurfacesoftheballs.Theheatingrate,givenbythe20

parameterb,alsoappearstobefasterfortheconventionalheatingmethod(0.0017)compared21

14

totheinductiveheatingmethod(0.0009).Thisisexpectedasthetemperaturecontrollerinthe1

conventionalmethodwasoperatedautomatically,whereastheinductionheatingwas2

controlledmanuallyduetothelimitationsoftheexistingequipment.3

3.3Yields4

Themassesoftheliquidproductandthecharleftbehindwerecollectedandquantified.5

Thedifferencefromtheoriginalbiomasswastakentodeterminethemassofgasreleasedfor6

eachexperiment.WithHDO,lowerliquidyieldsandhighergasyieldsareexpectedasorganic7

compoundsfromthedecompositionofligninandcelluloseundergosecondarycrackingto8

produceincondensablegasessuchasCO,CO2andCH4.Moreover,deoxygenationresultsin9

removalofoxygenintheformofCO,CO2andH2O.Watercontentalsoincreasedas10

dehydrationreactionstookplace(Figure5).Bothoftheseeffects,thesecondarycrackingand11

waterproductionreactions,resultedinaloweroilyieldforthecatalyzedruns,asiscommonly12

reportedinliteratureforthesetypesofprocessesandreactions[3,4,14,27].Thecomplete13

yieldvaluesarelistedinTable2.Loweroilyieldswereobservedforcatalystheatedwith14

inductionheatercomparedtoheatingtape;thisisattributedtohighercatalystfouling15

observedforheatingtape(discussedinsection3.6).Highercatalystfoulingimplieslower16

catalystactivityandlowerrateofHDOandcrackingreactionsresultinginhigherliquidyields.17

Table2.Yieldvalues(±std.error)18Sample Water(wt.%) Oil(wt.%) Char(wt.%) Gas(wt.%)

Baseline 18.48±0.31 22.52±1.31 20.00±0.00 39.00±1.00

HT237̊C 16.59±4.57 13.41±3.57 21.00±0.00 49.00±1.00

IH234̊C 19.23±1.85 6.77±0.85 20.00±2.00 54.00±1.00

IH286̊C 17.74±1.45 6.76±2.05 21.00±1.00 54.50±4.50

IH375̊C 16.09±0.62 5.41±2.12 23.50±1.50 55.00±0.00

19

3.4GasChromatography20

15

TheGC-MSspectracollectedfromtheoilphaseoftheliquidproductsareshownin1

Figure6.Thepeakswerelargelyidentifiedasphenoliccompounds,withtracesofalcohols,2

aldehydesandketones.Withoutup-conversion(baseline),theonlyhydrocarbonidentifiedwas3

thatattributedtoethylbenzene.Thispeakincreasedinintensityforallup-conversion4

experiments,butmarkedlysofortheinductiveheatingexperiments.Thephenolicpeaks,5

however,werelowestwiththeinductionheatingrunat234°Candgraduallyincreasedasthe6

temperatureofthebedincreased.PhenoliccompoundsgenerallyundergotheHDOreactionto7

formbenzeneorcyclohexaneafterthehydroxylgroupisremovedviadehydrationreactions8

[4].9

However,alkylethergroupshavebeenreportedtonegativelyinfluencethereactivityof10

thephenolswhilealkylgroupshaveapositiveinfluence[28].ThepeaksshowninFigure6show11

mostofthelatterremovedafterupgradingwiththeinductionheater,whiletheformerpersist12

albeitatrelativelylowerintensities.Asummaryofthecompoundsidentifiedwereclassifiedas13

hydrocarbons,phenols,orothers(includedalcohols,aldehydesandketones)andarelistedfor14

eachexperimentinTable3.15

Table3.Summaryoforganiccompoundspresentineachpyrolysisoil,basedonwt.%(±std.16

error).17Sample Hydrocarbons(Wt.%) Phenols(Wt.%) Other(Wt.%)Baseline 7.95±2.93 66.52±2.17 25.53±1.31HT237̊C 13.73±1.18 61.37±0.64 24.90±0.44IH234̊C 29.48±0.62 39.9±0.69 30.61±0.98IH286̊C 25.83±1.34 47.65±2.67 26.52±3.83IH375̊C 33.15±0.96 48.22±7.35 18.63±3.14

18

Phenoliccompoundsmadeuptwo-thirdsoftheoilcompositionbeforeupgrading.For19

thefirstcatalyzedexperimentusingtheinductionheateratthelowestcatalystbed20

temperature,thecompositionofphenolsdecreasedto40wt.%,whiletheamountof21

16

hydrocarbonsincreasedfrom8to30wt.%.WiththepresenceoftheHDOcatalyst,partial1

deoxygenationofthephenolstobenzenecanbeinferred.Theotherinductionheating2

experimentsrunathigherbedtemperaturesgavesimilartrendsforthehydrocarbons,butalso3

showedagradualincreaseinphenolswithincreasingbedtemperature.4

Fortheheatingtapeexperiment,asmallerriseinhydrocarboncompositionisobserved5

(to14wt.%)buttheprofileislargelyidenticalwithrespecttothebaselineexperiment.This6

suggeststhatthecatalystsurfacesitesinthisexperimentwerefouledorinhibitedrelatively7

fast,preventingtheinitiationofadsorptionoftheorganiccompound.Thiswouldimplyalarge8

temperaturegradientasaresultoftheslowtransferofheatfromtheexteriorofthetubeto9

theinterior.Thisphenomenonisdiscussedinmoredetailinthenextsections,wherethe10

catalystsurfacesareanalyzedpost-experiment.11

InadditiontotheGC-MSoftheoilphase,GCanalysisofthegasproductforCO,CO2and12

CH4wasperformed(Figure7).BesidesHDO,catalyticcracking,whichresultsintheremovalof13

theorganicelementsfromtheoilintothegaseousphase,canalsotakeplace.Theresultsfor14

theinductionheatingrunsshowaslightincreasingtrendforallthegaseousproductsasthebed15

temperatureincreased,withtheexceptionoftheCOunder375°C,whichdroppedsharply.As16

thebedtemperatureincreases,thevaporizedorganicmoleculesaremorelikelytoundergo17

additionalcrackingproducingmoregaseousproductsintheformofcarbonmonoxide,dioxide18

andsmaller-chainhydrocarbons[29].Thelargestandarderrorproducedfortheinduction19

heating375°CGCtest,suggeststhisdatapointasapossibleoutlier.Besidesthisincreasing20

trendwithtemperature,thereisnodiscerniblepatternofsignificancefortheGCgasanalysis.21

17

TheabsenceofadecreaseinCOandincreaseofCO2asaresultofthecommonoxidation1

activityforPtcatalyst[30],suggestsunfavorableconditionsforthisparticularreaction.2

3.5ElementalAnalysis3

ThedrybasisC,HandOcompositionsarelistedinTable4forthedifferentexperiments4

aswellasthebiomassandcharsamples.UsingthisdatawecandeterminetheO/CandH/C5

molarratiooftheoilsamplesfortheinduction-heatedandconventionally-heatedupgrading6

experimentsandcomparethemtotheoilwithoutdeoxygenation(Figure8).Forthe7

experimentrunat234̊Cwiththeinductionheater,theO/Cmolarratiodecreasedto0.51from8

1.36,a62.5%reductioninthemolaroxygen,thehighestreductionfromalltheexperiments.9

The284̊Cexperimenthadthesecondhighestreduction,downto0.81,a40%reduction.The10

highestbedtemperatureat375̊CandtheheatingtapeexperimenthavealmostidenticalO/C11

ratioscomparedtothebaseline.12

13

14

Table4Summaryoftheelementalcompositionforeachpyrolysisrun(±std.error)15Sample Carbon(Wt.%) Hydrogen(Wt.%) Oxygen(Wt.%)

PSDBiomass 49.5±1.00 6.1±0.85 44.7±0.52

Char 84.4±0.69 1.8±0.08 13.5±0.72BaselineBio-oil 32.3±1.61 9.5±0.66 58.2±2.28

Bio-oilHT237̊C 29.2±0.08 11.0±0.01 59.8±0.08

Bio-oilIH234̊C 52.8±5.32 12.7±2.35 34.5±3.02

Bio-oilIH286̊C 42.9±0.82 11.0±0.01 46.1±0.82

Bio-oilIH375̊C 28.5±0.67 9.4±1.59 62.1±0.92

16

At-testanalysisforeachexperimentcomparedtothebaselineO/Cshowedstatistical17

significancefortheIH234̊Crunonly,andnosignificancefortheremainingones.Inaddition,18

nostatisticalsignificancebetweenanygroupswasdeterminedusinganANOVAtestfortheH/C19

ratios.20

18

Thecokeformedinthecatalystwasalsoaccountedforbyrunningelementalanalysison1

thepellets,aftersinglepyrolysisrunswiththedifferentheatingmethods(Figure9).Clearly,in2

additiontoremovingOfromthefeed,asignificantportionoftheCisalsobeingremoved,3

leadingtoanincreaseintheO/Cratiointheoil.Forthecaseoftheheatingtape,26.75%ofthe4

totalbiomassweightwasfoundtobelostinthecatalystbedintheformofcoke.IftheCfrom5

cokeisaccountedforasshowninFigure8,thecalculatedO/Cmolarratiowouldbe0.06.The6

differencebetweenthisvalueandthereportedvalueoftheoil-onlyvalueof1.53(>96%)for7

theheatingsuggeststhedeoxygenationeffectwiththismethodishamperedduetothelossof8

theCfromtheoil.Inotherwords,theresultsfromtheheatingtapeandbaselineexperiment9

areinsignificantfromoneanother,duetothefactthatthemeasuredlossofOisoffsetbythe10

lossofCintheformationofcoke.Toalesserextent,thisisalsoseenwiththeIH234°C11

experiment,wherean8.75%lossofCmasswasnoticedduetothecokeformationonthe12

catalystbed.TheO/CratiocalculatedincludedtheCfromthecokewouldbe0.047.Datafor13

cokedepositionwasnotcollectedattheothertemperatures.14

InadditiontolosingCarbonoverthecatalystbedintheformofcoking,elementalmass15

balancesrevealthatCandOarealsoescapingintothegasphaseproportionatelydifferent16

comparedtothebaselinecompositions(Figure10).ThehigherO/Cratiosinthegasphase17

appearloweratthehighertemperatures,whichwouldleadtoourobservedresults,a18

respectivedecreaseintheO/Cratiooftheoilphaseatthesetemperatures.19

3.6Catalystfoulingandactivityanalyses20

Tounderstandthediscrepancybetweentheconventionalheatingandinductionheating21

methodforpyrolysisupgrading,thesurfacesofthecatalystswereexaminedusingNH3-TPDand22

19

BET,andCHNanalysisforcokeformation.Theacidityforthecatalystsafterasinglerunusing1

theinductionheatingmethodat234̊Cdecreasedfrom1.69to1.62NH3mmol/g,catalyst.2

Meanwhile,fortheheatingtapemethod,theacidicsitesdecreasedfrom1.69to0.924NH33

mmol/g,catalystafterasinglerun(Figure11),suggestingafoulingoftheavailableacidicsites4

andhindranceoftheadsorptionofoxygenatedcompoundsbyLewis-basedelectrontransfer.5

Oilcondensationandcokedepositiononthecatalystsurfaceblocksthecatalystpores,6

decreasingtheavailabilityofactivereactionsites.SinceHDOoccursmainlyonthestrongacid7

sites,adecreaseintheacidsitesduetoporeblockagewouldreduceHDO.ThespecificBET8

surfaceareasrevealedasurfaceareareductionfrom100.24to95.70m2/gfortheinduction9

heatingmethod,andto60.63m2/gfortheheatingtapemethod,respectively.Again,basedon10

theseresultsitcanbededucedthatthecatalyticactivesitesarebeingpoisonedunderthe11

heatingtapeatahigherratethantheinductionheatingmethod.12

Whilecokedepositionhindersthecatalystactivity,completecatalyticdeactivationwas13

notobservedforeitherofthemethods.FromTPDanalysis,itcanbeclearlyobservedthateven14

aftercokedeposition,somestrongacidsiteswereavailableforreaction,ensuringreusabilityof15

thecatalyst.Studiesofinductionheatingforcatalystre-utilizationwasrecentlyshownto16

performwellforothercatalysts[31],andeventhoughitwasnotundertakeninthiswork,17

basedontheTPDdatapresenteditisexpectedtoundergoasimilarbehavior.Regardless,this18

isanimportantissuethatwillbeaddressedindetailinafollow-upstudy.19

AsitwasearliershowninFigure9,elementalanalysistestedonthecatalystpellets20

revealedhigherCwt.%contentfortheheatingtapeexperimentafterasinglerun.Therapid21

poisoningofactivesitessuggestsinabilityofthecatalysttoadsorbtheorganicmoleculesto22

20

furtherdeoxygenateandreleasewater,aswellasalossofthecarboncontentinthecatalyst1

bed.ThisphenomenonwasalsodeducedfromtheGC,KF,andCHNanalysisperformedforthe2

heatingtapeexperiment,wheretheresultsresembledcloselytothoseobtainedforthe3

pyrolysisoilrunwithoutcatalyticupgrading.Thereasonforthebetterperformanceof4

inductionheatingasopposedtotheheatingtapecanbeattributedtodirectheatingofcatalyst5

bedintheinductionsystem.Fortheheatingtape,duetoinefficientheating,thecatalystbed6

actsasaheatsinkwhilethevaporphaseactsasaheatsource,drivingtheproductmolecules7

towardsthecatalystbedandcondensingonthesurface.Inaninductionheater,themetal8

catalystisdirectlyheatedwithouttheuseofheatcarrier.Thismakesthecatalystaheatsource9

ratherthanaheatsink,reversingthethermalfluxandensuringthemovementofproduct10

moleculesawayfromthesurfacereducingdepositionandblockageofactivesites.11

Lookingonlyattheinductionheatingexperiments,atrendappearstoshowthatwith12

increasingtemperaturesstartingfrom234°C,themolarO/Cincreases,andhencetheHHVof13

theoildecreases.Inaddition,ahigherpercentageofCarbonwasobservedtohavebeenlostat14

thehighertemperaturesinthegaseousphase.However,onemustalsolookattheinterior15

temperatureobtainedinthecatalystbedandoverlaythatinformationwiththeTPRandTPD16

profilesofthecatalystforhydrogenconsumptionandreactantadsorption.FromFigure11,the17

twoactivepeaksforreductionandacidsiteadsorptionappearataround167°Cand356°C.18

Thebedtemperaturewascalculatedforeachofthethreeexperimentsfromthesurface19

tubetemperaturemeasuredusingtheIRcamera.UsingFourier’sheatbyconductionlawfora20

multi-layeredcylindricalshell(Eqn.4),thetemperaturewithinthetubewasestimated,taking21

intoaccountheatlostduetoradiativeandconvectiveheattransfertothesurroundings.The22

21

resultsfortheinteriortemperaturesforeachexperimentarelistedinTable5.For1

simplification,T1istakenathalftheradialdistancefromthecentertotheinteriorwall,andthe2

bedofsteelballsisassumedtobeonesolidshell.Thesetemperaturesaresuperimposedover3

theTPprofilesinFigure11above.Thebedtemperatureat383°CforIH375fallsjustoutsideof4

thesecondreductionpeak,suggestingverylittletonohydrogenconsumptiononthecatalyst5

sitesarepossibleatthistemperature.6

7

Table5.InteriortemperaturesforthecatalystbeddeterminedusingFourier’sHeatby8

ConductionLawfora3-layeredshellcylinder,andthecalculatedresidencetimesforeach9

experiment.10

11

Q(W)=(T3-T1)/(RSteel+RTube) (Eqn.4)12

Experiment Q[W] T3[̊C] T1[̊C] t[s]HT237°C 169 237 232 8.46IH234°C 122 234 239 8.57IH286°C 168 286 292 7.01IH375°C 193 375 383 5.34

13

Meanwhile,theexperimentsrunat292°Cand239°Cfallclosetothepeakofthefirst14

reductionanddesorptionpeak.Theformershowedthesecond-highestreductionintheO/C15

ratio,withthelossofmoreCintothegasphasepossiblyexacerbatingthequalityoftheoil.At16

thesametime,thelowertemperature,whichliesclosertothefirstpeak,reflectingtheweaker17

acidsitesandreactivemetalsitesonthecatalystsurface,showedthehighestdeoxygenation18

effect.ThedifferencebetweenexperimentsIH234andHT237(relativelysametemperature)19

underscorestheadvantageofusinginductionheatingasaheatingsourceforthecatalystbed.20

Attemptingtoreachthefirstpeakwiththeconventionalheatingmethodwasshowntobe21

problematicasaresultofthepolycondensationofthebiooilvaporsatthelowtemperature.22

Thisislikelyduetothecoldspotsdevelopedastheheattransfersfromthewallstotheinterior23

22

ofthebed,andthepelletsdevelopingnegativetemperaturegradientsacrosstheirsurfaces.1

Meanwhile,atthesametemperaturewiththeinductionheating,partialdeoxygenation2

indicatesthatmovingclosertothefirstpeakismuchmorepossiblewhileavoidingsignificant3

condensation,astheheattransfersfromtheinteriorofthebedtothewalls,andminimizing4

thetemperaturegradientsacrossthesurface.5

Anotherfactortoconsideristhecontacttimeofthereactantswiththecatalystsites.6

TheresidencetimesforeachexperimentarealsolistedinTable5,withtheexpansionofthe7

gaswithtemperatureincreasestakenintoaccountusingtheidealgaslaw.Withhigher8

temperatures,thecatalystcontacttimedecreasedsignificantlywhichsuggestslesstimefor9

HDOtotakeplace.Arecommendationforfutureworkwouldbetoincreasethelengthofthe10

tube,aswellasthecoil,forlongerresidencetimes.11

3.7EnergyBalances12

13

TheHHVsoftheoilphasesforeachexperimentarelistedinTable6.Asshown,theHHV14

valueofthebio-oilupgradedatthelowestinductionheatedcatalystbed,28.82MJ/kg,isalmost15

twicethevalueobtainedfortheheatingtapeexperiment(15.00MJ/kg),whichisalmost16

identicaltotheHHVoftheoilwithoutup-conversion(14.12MJ/kg).17

Table6.EnergyBalances(withstd.errors)18

19

Experiment HigherHeatingValueoftheoil(MJ/kg)

InputEnergy-processequipment,biomass(kJ)

OutputEnergy-char,oil,gas(kJ)

NetLoss(kJ)

BiomassEnergyRecovered(%)

CONTROL 14.12±1.91 1466±7.14 105±4.50 1361±5.97 53.2±0.36

HT237̊C 15.00±0.04 1826±7.14 88±0.14 1738±5.05 44.6±1.69

IH234̊C 28.82±0.55 1766±7.14 105±3.55 1661±5.64 53.3±0.13

IH286̊C 22.81±0.16 1886±7.14 108±4.21 1779±5.86 54.7±0.15

IH375̊C 12.06±2.23 2066±7.14 110±2.87 1956±5.44 56.0±0.57

23

Theenergyinputsandoutputsforeachpyrolysisexperimentoverthedurationofthe1

run(20min)arealsolistedinTable6,withthenetlosslistedinthethirdcolumn.Theinput2

energyincludedtheoperationalequipmentrunningduringthepyrolysissuchastheinduction3

heater,ESP,aswellasthecalorificvaluesofthebiomassandhydrogengasflowingin.The4

valuesintheenergyoutputwerethederivedcalorificvaluesofthechar,oilandgasproducts.5

Beingunabletomeasurethehydrogenexitingthesystemaswellasotherlowmolecularweight6

hydrocarbons(C2-C5)[14],ournetlossesmayappearlargerthanactuallosses.7

Thedeterminednetlossappearedhigherfortheheatingtapeexperimentcomparedto8

itssimilarinductionheatingcounterpart.Thisisaresultoftheminimal-to-nodeoxygenation9

achievedintheheatingtapeexperiment,comparedtotheinductionheating.Theinduction10

heatingexperimentsathigherbedtemperatures(286̊Cand375̊C)predictablyshowedmuch11

highernetlossesasaresultofthenecessaryadditionalpowertomaintainthehigher12

temperatures,withlittleadditionalupgradingoftheoiltocontributetowardahigherHHV.13

Theenergyvaluesrecoveredinourproductsfromtheoriginalbiomassarelistedfor14

eachexperiment.Alltestsrevealedroughlyequalrecoveryamounts,exceptfortheheating15

tapeexperimentwhichhadthehighestlossofCinthecatalystbed.Whiletheenergy16

recoveredisidenticalfortheboththeupgradedandnon-upgradedexperiments,mainlydueto17

thelossoftheoilyieldintheformer,itisimportanttonotethattheenergyisdistributed18

amongfewermoleculesasshowninourGC-MSspectraearliercomparedtothebaseline.This19

indicatestheupgradedproductismorehomogenous,stableandextractablecomparatively.20

Rawbio-oilcontainshundreds,eventhousands,oforganiccompounds,makingtheprocessof21

separatingandcollectingthedesiredcompoundsarduousandcostly[32].Italsoincreasesthe22

24

reactivitywithintheoilmakeupasthesemostlyoxygenatedcompoundsinteractwitheach1

otherandalterthechemicalcompositionoftheoil.This‘aging’oftheoilnotonlydeteriorates2

thequalityoftheoil,butalsocomplicatesthechemicalextractionprocess[31,32].Byreducing3

thechemicalmakeupoftheoiltoahandfulofcompoundsandconcentratingtheenergy4

density,separationcostsarereducedandspontaneousreactionsarelesslikelytotakeplace.5

Tomitigatetheenergylossesinourprocess,theuseofinsulationontheboththe6

biomassandcatalystbedtubeswouldassistinthereductionoftheamountofpowerneededto7

maintainbothreactortemperatures,byminimizingradiativeandconvectiveheatlossesThe8

insulationcouldnotbeusedinthesestudiesduetotheoperationoftheupgradingequipment9

atverylowpowerlevels(3-5%),veryclosetotheminimumpossibleforstableoperations(the10

equipmentisnotdesignedtooperateat1-2%ofthemaximumpower).Thus,theequipment11

wasoperatedinanenergyinefficientmannerinordertopreventequipmentmalfunction,as12

additionalinsulationwoulddropthepowerrequirementsbelowthislimit.13

Inaddition,scalingupboththebiomassandcatalystamountswillhelpreducethenet14

lossbyincreasingouroutput-to-inputenergy.Thereactorsizeswouldremainidentical,asthey15

werenotoptimizedinthisexperiment,andthelargerbiomassandcatalystpelletloadingswill16

increasetheeffectofHDO,andimprovetheenergyrecoveryoftheupconversionprocess.17

4.Conclusion18

Usinginductionheatingasasourceforasteel-packedcatalystbed,up-conversionof19

sawdustpyrolysisoilwasachievedbypartialdeoxygenationwithPt/Al2O3.Theoptimal20

temperatureofthebedneededforhydrogenreductionwasdeterminedtobearound230-21

240°C.Aconventionalheatingmethod,usinganelectricheatingtapeasanexternalheatsource22

25

wasusedasacontrol.Inthiscontrolexperiment,heatingthebedtothesameoptimal1

temperature(asobservedininductionheating)resultedinrapidfoulingofthecatalystviacoke2

formationwithlittle-to-nodeoxygenation.Thestudydescribedinthispaperhelpssupport3

inductionheatingasalucrativeheatingsourceforacatalystbedcoupledwithconductive4

materialtoaidindrivingthetemperaturegradientfromtheinteriortotheexteriorofthetube,5

andavoidingheattransferloss.Thisopensthedoortolookingatcatalyticsupportswithhigh6

electricalconductivitytoincreasethelifetimeofthecatalystbyheatingthepelletsdirectlyand7

preventingthedepositionofcokeandotherpollutants.8

Acknowledgements9

ThisworkwasfundedbytheNationalScienceFoundation(NSF)(#CBET1437810).Partial10

supportwasalsoprovidedbytheLSUAgCenter,theDepartmentofBiologicalandAgricultural11

EngineeringatLSU,USDANIFAviaHatchProgram(projectLAB#94196),LouisianaBoardof12

RegentsEnhancementProgram(award# LEQSF(2015-17)-ENH-TR-01),andLouisiana13

TransportationResearchCenter(proposal#40201).TheauthorswouldliketothankDr.James14

Spivey,ZiWang,Dr.NitinKumar,Dr.TommyBlanchard,Dr.CharlieMilan,ConnieDavid,15

GustavoAguilarandCharlesHenkelfortheirtechnicalassistanceduringthesestudies.The16

manuscriptwaspublishedwiththeapprovaloftheDirectoroftheLouisianaAgricultural17

ExperimentStationasmanuscript#2016-232-27532.18

References19

[1]T.Dickerson,J.Soria,Energ.,6(2013)514-538.20[2]P.M.Mortensen,J.-D.Grunwaldt,P.A.Jensen,K.Knudsen,A.D.Jensen,Appl.Catal.A:Gen.,40721(2011)1-19.22[3]J.Payormhorm,K.Kangvansaichol,P.Reubroycharoen,P.Kuchonthara,N.Hinchiranan,Bioresour.23Technol.,139(2013)128-135.24[4]M.Zanuttini,C.Lago,C.Querini,M.Peralta,Catal.Today,213(2013)9-17.25

Figure1.IRImage.ThermalimagerecordedbytheuserinterfaceoftheThermaCAM

Professional9.1dataacquisitionsoftware(left),usedtomeasureinfraredradiationofheated

surfaces,comparedtoimageofactualcatalystbedenvelopedincoil(right).

Figure2.TPD&TPRProfiles.Temperature-programmedreductionwithH2andtemperature-

programmeddesorptionwithNH3profilesforthePt(1wt.%)/Al2O3pellets.

Figure3.HeatingProfiles.TemperatureplotsrecordedusingIRcameraandThermaCamdata

acquisitionforcatalystbedheatedunderRFinductivefieldat3differentpowers:250W,350W,

and500W,andwithelectricalheatingtape(HT300W).

Figure4.Steady-StateTemperatures.Maximumsteadystatetemperatureareplottedforthe

catalystbedwithnosteelballs,thebedmixedwithsteelballsandheatedat3differentpower

levels,andthebedheatedwithelectricalheatingtape.

Figure5.Water&Bio-oilYields.Waterandoilcompositionofpyrolysisliquidproduct,

determinedusingKFtitration.

Figure6.GasChromatographyMassSpectrometry.GC-MSspectrafortheinductiveand

conventionalheatingsamples,at234̊Cand237̊Crespectively,comparedtothenon-upgraded

oilsample.

Figure7.CO,CO2,CH4Quantification.GC-Gasanalysisofthegassamplescollectedduring

pyrolysisforcarbonmonoxide,dioxideandmethanequantification.

Figure8.MolarO:C,H:C.Oxygen-to-carbon,andhydrogen-to-carbonmolarratiosforthe

controlandupgradedsamplesbasedontheirelementalanalyses.Forthetwoheating

comparisonexperiments(234/237̊C),theratiosaccountingforthecokedepositedoncatalyst

isalsodisplayedtounderscoreeffectofthedepositionontheoverallO/Ccontentoftheoil

betweenthetwomethods.

Figure9.CokeContent.CelementalanalysisonthePt/Al2O3pelletsaftersinglepyrolysis

upgradingrunsforthetwoheatingcomparisonexperiments,reflectingcokedeposition

quantity.

Figure10.ElementalMassBalances.C(a),O(b),andH(c)wt.%balancesovertherespective

productsformed.

Figure11.TPD&TPRProfiles.NH3-TPDprofilesforfreshcatalysts(control)comparedto

inductively-heated(IH234̊C)andconventionally-heated(HT237̊C)catalystsaftersinglerun

pyrolysisup-conversion.

0

2

4

6

8

10

12

14

FreshPellets

IHPellets

HTPellets

C(wt.%)

0%

10%

20%

30%

40%

50%

60%

70%

Baseline HT237 IH234 IH286 IH375

wt.%

CBalance

Char Oil Catalyst Gas

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%


wt.%

OBalance

Char Oil Water Gas

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%


wt.%

HBalance

Char Oil Water Gas

O:CStatisticalAnalyses

t-Test:Two-SampleAssumingUnequalVariances

Control HeatingTape

Mean 1.357296731.53513545

Variance 0.029120697.2675E-05

Observations 2 2

HypothesizedMeanDifference 0

df 1

tStat -1.4719709

P(T<=t)one-tail 0.18994816

tCriticalone-tail 6.31375151

P(T<=t)two-tail 0.37989632

tCriticaltwo-tail 12.7062047


Control IH250

Mean 1.357296730.50723139

Variance 0.029120690.0229736

Observations 2 3


df 2

tStat 5.70292622

P(T<=t)one-tail 0.014699


P(T<=t)two-tail 0.02939801



Control IH350

Mean 1.357296730.80908282

Variance 0.029120690.00358496

Observations 2 4


df 1

tStat 4.40953979

P(T<=t)one-tail 0.07098597


P(T<=t)two-tail 0.14197194



Control IH500

Mean 1.357296731.63319773

Variance 0.029120690.00040361

Observations 2 2


df 1

tStat -2.2707977

P(T<=t)one-tail 0.13204133


P(T<=t)two-tail 0.26408266


H:CStatisticalAnalyses

Control 3.009348923.020220213.452016433.59269121

HT 2.368972932.252667474.542463214.5185608

IH234 4.359633624.267853523.16363552

IH286 3.010397182.968247133.192252663.19326012

IH375 4.753094893.22692491

Anova:SingleFactor

SUMMARY

Groups Count Sum Average Variance

Control 4 13.07427683.268569190.08919345

HT 4 13.68266443.4206661 1.64469362

IH234 3 11.79112273.930374220.44302207

IH286 4 12.36415713.091039270.01409144

IH375 2 7.9800198 3.9900099 1.16459739

ANOVA

SourceofVariation

SS df MS F P-value Fcrit

BetweenGroups 1.922569434 0.480642360.7906844 0.5532189 3.25916673

WithinGroups 7.2945770412 0.60788142

Total 9.2171464716

Documents

Ex-situ up-conversion of biomass pyrolysis bio-oil vapors