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ArticleID:025322409(2005)0620650206Receiveddate:2005210202;Receivedinrevisedform:2005212204Authorintroduction:WeigangLin,Ph.D.,AssociateProfessor(DTU),andProfessor(IPE),major:chemicalengineeringandthermalenergyengineering.E2mail:wl@kt.dtu.dkandwglin@home.ipe.ac.cn.PowerproductionfrombiomassinDenmarkWeigangLin1,2,WenliSong2(1.DepartmemntofChemicalEngineering,TechnicalUniversityofDenmark,Building229,DK22800,Lyngby,Denmark;2.MultiphaseReactionLaboratory,InstituteofProcessEngineering,ChineseAcademyofSciences,Beijing100080,China)Abstract:Denmarkhasthebestknowledgeandknow2howofconvertingstrawtoenergyandmanufacturingstrawfiredboilerplant,fromwhichmanyconceptsmaybelearned.Inthispaper,anoverviewofpowerproductionfromtheannualbiomass,theproblemsofthebiomass2basedplantsandthecorrespondingresearchactivitiesarepresented.Keywords:biomass;power;combustion;fouling;corrosion;emissionCLCnumber:X71Documentcode:ATheconsequencesofcarbondioxide(CO2)in2ducedglobalwarmingcausemajorconcernworld2wide.Rapidincreasesintheconsumptionofenergyproducedwithfossilfuelsoverthepastcenturyareamajorfactorcontributingtotheglobalwarmingandotherproblems.Biomassisarenewableenergysourcethatcanbestored,whichisanadvantageoverotherformsofrenewableenergy.Biomasscanbeusedtoproducepower,heatandliquidfuelsbythermalandbiochemicalconversion.Chinaisfacingachallengeofenergyshortageandenvironmentalpressureduetothefastgrowingofeconomyandrelativelylowefficiencyofenergyutili2zation.TheChinesegovernmenthasagoalfor2020thatthepowerfrombiomasswillreachacapacityof20GW[1].Inordertoachievethisgoal,advancedtechnologiesofusingbiomassasafuelareneededur2gently.Manyinvestigationsarebeingperformedonbiomassconversionprocesses,includingproductionofethanolfrombiomass,biomassgasificationetal..Inlarge2scaleusageofbiomass,thehighestinterestseemstobefocusedonpowerproduction,i.e.pro2ductionofelectricityamongtheavailabletechnolo2gies.Themostfavorableconditionsforpowerpro2ductionbasedonthermalconversionofbiomassareinmediumorlargescale,whichenablesutilizationofanefficientsteamcycle[2].InChina,thedemandforpowergenerationfromagriculturalresiduesishigh,especiallyintheagriculturalareas.TheNationalDe2velopmentandReformCommissionhasapprovedtobuildseveraldemo2plantsinHebei,ShandongandJiangsuprovince.However,thefundamentalresearchoncombustionofbiomassisfarbehindthedemand.Onemisleadingopiniononbiomasscombustionisthatbiomassiseasytoburnandtheavailablecoalcom2bustiontechnologycanbedirectlyusedforbiomass.Actually,Biomass,theannualagriculturalresiduesinparticular,isamoredifficultfuelthancoal,oilandnaturalgas,amongotherthingsbecausethecalorificvalueislowerandbecauseofthecontentofchlorineandalkalimetalthatreactaggressivelyandcorrosivelyundertheoperatingconditionscharacteristicofsteamturbineplantsingeneral,withhighsteampressureandtemperatures.Inaddition,theagriculturalresi2dues,isdistributedtolargeareas,whichlimitsthesizeofpotentialpowerplants.Technicallysizeofbi2omass2basedpowerplantisnotlimitedbutinvestmentandoperationcostofverysmallpowerplantisusuallyveryhighcomparedtolarge2scalepowerproduction.Denmarkhasasuccessstory,bothontheknow2howofconvertingstrawtoenergyandmanufacturingstrawfiredboilerplant.ThetechnologiesarebasedonthehighefficiencyCombinedHeatingandPower(CHP)systemfortheplantswithrelativelylowca2pacityandUltraSuperCritical(USC)forthelargeco2firingplant.TheDanishexperiencemaybeusefulforChinesedevelopmentofbio2powerinrelativelylargescaletofulfilltherequirementofrapidlyin2creasedpowerfrombiomass.Theobjectiveofthispaperistopresentanoverviewofpowerproductionfromtheannualbiomass,theproblemsofthebio2mass2basedplantsandthecorrespondingresearchac2tivitiesinDenmark.1OverviewDenmarkstartedtoutilizebiomassasanenergyresourcesince1970stosecuretheenergysupply.In1989theburningbyfarmersoftheformerlylargea2mountsofsurplusstrawinthefieldswasprohibited.Denmarkhasanationaltargetofreducingcarbondi2336200512JournalofFuelChemistryandTechnologyVol.33No.6Dec.2005©1994-2007ChinaAcademicJournalElectronicPublishingHouse.Allrightsreserved.[2,3].Therefore,theDanishParliamentinstructedthee2lectricityutilitycompaniestouseabout1.5milliontonsofbiomassannuallyinthecentralizedCHPbytheyear2005.Intheyearof2001,morethan1.3milliontonsofwoodand750,000tonsofstrawareusedinpowerplants[4],aswellasinindustries,districtheat2ingplants,farmsandprivatehouseholds.AccordingtotheDanishenergypolicythepartofbiomassintheen2ergysupplypatternwillcontinuetoexpandinthefu2ture.Thefutureuseofbiomassisoutlinedinthena2tionalenergystrategyplan:Energy21from1996.Inthisveryambitiousplan,utilizationofwoodandstrawinDenmarkshouldbe9milliontons(105PJ)byyear2030[5].TheincreaseofbiomassinthepowerindustryinDenmarkisshowninFigure1.Figure1Increaseofbiomassusageinpowersector[4]Until2002,Denmarkhas50heatingplantsoper2atingonwoodchips,25onwoodpelletsand75straw2firedplants[6].Moststand2alonesteampowerplantsfirebiomassondifferentgratesystems.Theseunitshavebeenofasizebetween2.5and35MW(e)withlittlepre