Liquid biofuels from biomass Bioethanol, biomethanol ... · • Bioethanol , biomethanol, other ... CO2 and Energy balance of biofuels (2) • Source: EU C6370 Peter Lund 2015 ...

C6370 Peter Lund 2015

Lecture 11_a

Biofuels

•  Liquidbiofuelsfrombiomass

•  Bioethanol,biomethanol,other

•  Feedstocks,productionprocesses

•  Energybalances,potentials

Biofuel use today


•  USA&Brasilia96%ofbioethanol,Germany60%ofbiodiesel

•  EU:10%ofallfuelsin2010needtobebiobased

World market trends of biofuels

C6370 Peter Lund 2015 Source: UPM/Sohlström


Issue of conflicts with food production in the future?

Food and fibres

biofuel

Examples of biofuel chains


Processes Products Biomass source

Sugar+starch Sugarcane, sugarbeats, maize, corrn

Fatty acids (oils) Rape, palm, jatropha

Cellulose Grass, bagasse, straw, wood

Source: UPM/Sohlström


Basics of biofuels (liq)

•  ChemicalformsofbiomassCO2+sun+water→sugar

starch(e.g.corn) Cellulose+hemicellulose (differentpolymericformsof carbohydrates)

+lignin=wood•  Liquidformsofbioenergy

–  Ethanol(fermentationandmethanol(thermalprocess)–  ETBEandMTBE)(additivesingasoline) –  Gasohol(85%ethanolormethanol+15%gasoline),M85jaE85–  Rapeseeds(biodiesel),NeXT-biodiesel(NesteOil)–  BTL,Fischer-Tropschprocesses


Biomass composition

•  CarbohydratesCm(H2O)nclassi[iedaccordingtotheamountofsugarmolecules:mono,di,tri,polysaccharides;5Catoms=pentose,6Catoms=hexoses

•  Sugars–  Canesugar(=sucrose)àglucose+fructose(six-carbonsugars)throughhydrolysis

•  Starch–  Polysaccharid;hydrolysisofstarch(acidoramylase)yieldsglucose–  70%ofcornisstarchamixofstraight-chainedandbranchedpolymersofglucose,molecularweightsupto1-2million)

•  Cellulosicbasedbiomass–  Carbohydratepolymers:cellulose,hemicellulose,;lignin–  Celluloseiscomposedoflongchainsofglucosemoleculeswithacrystallinestructure

–  Hemicellulosecontainsdifferentsugars,nocrystallinestructure(inhardwoodxylose)


Sources of biofeedstocks for ethanol


Production of ethanol

•  Producedthroughfermentation•  Biomass+biocatalystsàethanol

–  Starch+enzyme(amylase)oracid→glucose(sugar)–  Cellulose+enzyme(cellulase)oracid→glucose–  Hemocelluose+xylose→differentkindofsugarse.g.xylose→

•  Lowyieldsofethanol–  Glucose(fermentation,bacteria)→ethanol–  Theaboveprocessedworkinnaturalconditions,enzymescatalyzejustonereactionatime


Process steps for ethanol from lignocellulosic biomass (2 gen biofuels)

•  Pretreatmentofbiomassfeedstock•  Hydrolysis(sugar)•  Ethanolfermentation(ligninaswaste)•  Biomasspretreatedtobeenzymesensitive(e.g.

weekacid,0.5%sulphuracid)→hemicellulosehydrolysesintoxylose→celluloseandligninremains

•  Basicreactioninvolved–  Hemicellulose:(C5H8O4)n+nH2O→nC5H10O5–  Cellulose:(C6H10O5)n+nH2O→nC6H12O6–  (C6H12O6)n+nH2O→2C2H5OH+2CO

•  100kgfeedstock→50-60kgethanol;½turnsintoCO2,but96%oftheheatingvalueofcelluloseremains

•  1000kgstarch/cornà440lethanol•  Theprocessyields3-12%alcohol,restiswater

whichneedtoberemove(needsenergy)

yeast

cellulase acid


Energy balance of ethanol


Production of biomethanol

•  Methanolisanimportantindustrialchemical(ca30billionl/year)

•  Two-stepprocess–  1)syngasproduction,2)catalyticconversionintomethanol

–  Biomassgasi[icationàsteamreformationàShiftreactionàMethanolsynthesis

•  Chemicalreactions:–  Biomass+H2O→CO+H2(syngas)–  CO+H2O→CO2+H2(shiftconversion)–  2H2+CO→CH3OH+heat(methanol)–  3H2+CO2→CH3OH+H2O


Energy balance of biomethanol


Biodiesel from oilseeds(1 gen) •  RME=rapemethylester;n0.6-1ton/ha•  Separation:rape(3000kg)→rapeoil(1000kg)+proteincake(1900kg)•  Esteri[ication:rapeoil+methanol→glyserine(110kg)+RME(1000kg)•  Tropicalplants:jatropha1,6-3,2ton/ha;palmoil4-6ton/ha

Jatropha

•  Non-eatbale,oil-seedplant•  Growsinhumbleconditions


Biorefineries (2 gen of biofuels)


Biofuels through thermochmical conversion- step 1


Biofuels through thermochmical conversion- step 2


Biorefinary products (BTL)


Summary of energy ratios of biofuels from different sources

•  Cellulosicethanol 2-36•  Palmoil 9•  Sugarcaneethanol 8•  Wastebiodiesel 6•  Soyadiesel 2-3•  Cornethanol 2(USA)•  Cornethanol 1.2•  Diesel 0.8-0.9•  Gasoline 0.8•  Oilshale 0.75

•  Energyratio=energyoutput/energyinputs



Energy balance of biofuels (1)

•  Source:Science


CO2 and Energy balance of biofuels (2)

•  Source:EU


Energy benefits from biofuels (3)

Production price trends for biofuels

•  Sugarcanebioethnanol0.2-0.25€/l(gasolineequivalent)•  Cellulosicethanol0.25-0.55•  Cornethanol(USA)0.3-0.45•  Cornethanol(EU)0.35-055•  Wastebiodiesel0.2-0.3•  Soyadiesel0.30.55•  Rapeiesel0.3-0.55•  FTbiodiesel0.35-0.6


Your Work # 11 •  HomeworkfromLecture11

–  Howseverearetheissuesrelatedtobiofuelproduction?Biodiversity,con[lictswithfoodproduction,humanrights,etc.

–  Wewillspendtogether5minutesonthisquestion

•  InpreparingforLecture12(fuelcellsandH2)–  Havealookonfc&h2stuff,justoverview)


Extras


Conversion of biomass into biofuels

•  Thermal,chemicalandbiochemicalprocessesforconvertingorganicmaterialintobiofuels



EU:s own feedstock sources for biofuel production

•  Biofuel production could meet 10-20% of EU’s fuel need,

•  Example of land-area needed to produce 6% of EU fuel needs

Lähde: EEA


Nya biobränslen (ersättning av olja)

•  Tra[ikensbränslebehov4.000.000ton/år•  EU-direktivet:biobränslenminst230.000ton/år2010;Inhemsk

produktion100.000-200.000ton/årmöjligtenligtodlingsarealen(biodieselochetanol)

•  Framtidaenergiodlingar–  Rapsochrybs0,6ton/ha(biodiesel);[inskproduktionmotsvararca45.000tonRME/år;max.300.000ton(100%avdjurfodersombiprodukt)

–  Bioetanolfrånsockerbetor(1000milj.kg)~150.000ton;35ton/ha;ca0.4€/litermeddagensintäktsnivå

–  Rör[len30MWh/ha(metan40.000km/haellerfastbränsle);t.ex.500.000ha=1.500.000tonbiogas

•  Biogas(metan)–  Samhällsavfall;livsmedelindustrin0,6;avfallsvatten0,9;jordbruksavfall30-140;energiodlingar7;sopgas0,7TWh/år


alcohols have a lower air/fuel ratio, higher latent heat, lower flame temperature, higher octane number

Liquid biofuels from biomass Bioethanol, biomethanol ... · • Bioethanol , biomethanol, other ... CO2 and Energy balance of biofuels (2) • Source: EU C6370 Peter Lund 2015 ...

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