6-Interactions-of-biomass-components-during-pyroly

JournalofAnalyticalandAppliedPyrolysis90(2011)213–218ContentslistsavailableatScienceDirectJournalofAnalyticalandAppliedPyrolysisjournalhomepage::ATG-FTIRstudyQianLiua,∗,ZhaopingZhonga,ShurongWangb,ZhongyangLuobaSchoolofEnergy&Environment,SoutheastUniversity,Nanjing210096,ChinabStateKeyLaboratoryofCleanEnergyUtilization,ZhejiangUniversity,Hangzhou310027,ChinaarticleinfoArticlehistory:Received24August2010Accepted18December2010Availableonline24December2010Keywords:BiomassComponentPyrolysisInteractionVolatileabstractThepyrolysisofsyntheticbiomasssamplesasthree-component(viz.hemicellulose,celluloseandlignin)mixtureswasinvestigatedbyusingthetechnologyofthermogravimetricanalyzercoupledwithFouriertransforminfraredspectrometer(TG-FTIR).Theresultsrevealtheoccurrenceofinteractionsamongbiomasscomponentsduringpyrolysis,especiallytheinfluenceoflignintohemicellulosebelow327◦Candthatofhemicellulosetocelluloseabove327◦C.ByanalyzingtheFTIRspectracarefully,itwasfoundthatthepresenceoflignindecreasedtheyieldof2-furaldehydeandCOcontainingcompounds.Theexistenceofhemicelluloseintensivelydecreasedtheyieldoflevoglucosan,andlargelypromotedtheformationofhydroxyacetaldehyde.©2010ElsevierB.V.Allrightsreserved.1.IntroductionAsarenewableandCO2-neutralresource,biomasshasarousedagreatinterest.Therearetwowaystoreleaseheatandenergyfrombiomass:directcombustionorthermo-chemicalconversion[1].Thereintopyrolysisisaresearchtopicbecauseitcouldcon-vertbiomassintohigh-qualityfuelsorfinechemicals.Alsoitisthefirststepintheprocessofgasificationandcombustion.Biomassismainlycomposedofcellulose,hemicelluloseandlignin,whichpyrolyzeatdifferenttemperatureswithvariousvolatilesandheatvalues.Moreover,theexistenceofinorganicsaltsinfluencesthepropertyofvolatiles,decreasestheyieldoftarandpromotestheformationofchar[2,3].Anumberofstudiesonpyrolysisofbiomasscomponentswerereportedintheliterature.Themajorityofthoseconcerncellulose[4,5],andafewareabouthemicelluloseandlignin[6,7].Usuallythemaincomponentsofbiomass,viz.cellulose,hemi-celluloseandligninareconsideredtopyrolyzeindependently.Alenetal.[8]investigatedthepyrolysisbehaviorofpinewoodanditsmaincomponentsbypyrolysis-gaschromatographywithmass-selectivedetection(Py-GC/MSD),andindicatedthatwoodappearedtobehaveasthesumofitsconstituents.ThefastpyrolysisofbirchwoodanditsmaincomponentswerestudiedbySven-sonetal.[9],andthecalculatedcharyieldbyaddingthoseforthethreecomponentstogetherintheproportionsofbirchwoodwasconsistentwiththebirchwooddata,supportingthatthethreecomponentsactindependentlyduringpyrolysis.Yangetal.[10]∗Correspondingauthor.Tel.:[phone];fax:[phone].E-mailaddress:[e-mail](Q.Liu).reportedthatthepyrolysisofsynthesizedsamplesindicatedneg-ligibleinteractionamongthethreecomponents.Biaginietal.[11]appliedasummativelawfortheTGresultstoobtainthechemicalcompositionofbiomass,andtopredicttheFTIRprofilesofvolatilesreleased.Thecalculatedvalueswereingoodagreementwiththeexperimentalones,showingnointeractionamongthecomponents.Recentlyafewliteraturesproposedthatsomeinteractionsamongthethreemaincomponentsexistedinbiomasspyrolysis.Hosoyaetal.[12]observedthatlignininhibitedthethermalpoly-merizationoflevoglucosanformedfromcelluloseandenhancedtheformationofthelowmolecularweightproductsfromcel-lulosewithreducedyieldofcharfraction;cellulosereducedthesecondarycharformationfromligninandenhancedtheformationofsomelignin-derivedproductsincludingguaiacol.Moreoverthesolid/liquid-andvapor-phaseinteractionsbetweencellulose-andlignin-derivedpyrolysisproductswerereported[13].Worasuwan-naraketal.[14]alsoobservedsignificantinteractionsbetweencelluloseandligninduringpyrolysis.Dissimilarly,theyledtoadecreaseintaryieldbutanincreaseincharyield.Wangetal.[15]investigatedthepyrolysisofsynthesizedbiomasssamplesundersyngasbythermogravimetricanalysis,andfoundthatbothligninandhemicellulosecouldaffectthepyrolysischaracteristicofcellu-losewhiletheycouldnotaffecteachotherobviously.Sagehashietal.[16]studiedthesuperheatedsteampyrolysisofbiomassandpredictedtheproductsbasedontheindividualcomponents,andfoundthattheyieldsofphenol,guaiacolandaceticacidwereunderestimated,whiletheyieldsoffurfuralsandlevoglucosanwereoverestimated,showingpossiblesynergeticeffectsamongthecomponents.ThesteamgasificationofbiomassandthethreemaincomponentswasinvestigatedbyFushimietal.[17].Thepre-dictedyieldofwater-insolubletarwassubstantiallylessthanthat0165-2370/$–seefrontmatter©2010ElsevierB.V.Allrightsreserved.doi:10.1016/j.jaap.2010.12.009214Q.Liuetal./JournalofAnalyticalandAppliedPyrolysis90(2011)213–218Table1Proximateandultimateanalysisofthesamples(asreceivedbasis).SampleMarAarVarFCarQ(MJ/kg)CHNSOCellulose6.60.091.42.015.842.25.90.10.045.2Xylan6.55.176.412.015.640.86.40.20.041.0Lignin6.51.589.32.721.252.74.00.70.134.5ofrealbiomass,implyingthattheevolutionoftarfromligninwasenhancedbyothercomponents.Ontheotherhand,thevolatiliza-tionofwater-solubletarderivedfromcellulosewassuppressedbylignin,andtheinteractio