Green Energy and Technology Ayhan Demirbas · M. Fatih Demirbas Algae Energy Algae as a New Source of Biodiesel 123 AyhanDemirbas M.FatihDemirbas ProfessorofEnergyTechnology SilaScienceandEnergyUnlimitedCompany SirnakUniversity UniversityMah. Sirnak 24AkifSaruhanCad.,MekanSok. Turkey 61080Trabzon Turkey ISSN 1865-3529 ISBN 978-1-84996-049-6 e-ISBN 978-1-84996-050-2 DOI 10.1007/978-1-84996-050-2 SpringerLondonDordrechtHeidelbergNewYork BritishLibraryCataloguinginPublicationData AcataloguerecordforthisbookisavailablefromtheBritishLibrary LibraryofCongressControlNumber:2010929649 ©Springer-VerlagLondonLimited2010 Apartfromanyfairdealingforthepurposesofresearchorprivatestudy,orcriticismorreview,asper- mittedundertheCopyright, DesignsandPatents Act1988,thispublication mayonlybereproduced, storedortransmitted,inanyformorbyanymeans,withthepriorpermissioninwritingofthepublish- ers,orinthecaseofreprographicreproductioninaccordancewiththetermsoflicensesissuedbythe CopyrightLicensingAgency.Enquiriesconcerningreproductionoutsidethosetermsshouldbesentto thepublishers. Theuseofregisterednames,trademarks,etc.,inthispublicationdoesnotimply,evenintheabsenceofa specificstatement,thatsuchnamesareexemptfromtherelevantlawsandregulationsandthereforefree forgeneraluse. Thepublisherandtheauthorsmakenorepresentation, expressorimplied,withregardtotheaccuracy oftheinformationcontainedinthisbookandcannotacceptanylegalresponsibilityorliabilityforany errorsoromissionsthatmaybemade. Coverdesign:WMXDesign,Heidelberg,Germany Printedonacid-freepaper SpringerispartofSpringerScience+BusinessMedia(www.springer.com) Preface This book examines the production of algae culture and usage of algal biomass conversion products. In this book, the modern biomass-based transportation fuels biodiesel, bio-oil, biomethane, biohydrogen,and high-value-addedproducts from algaearebrieflyreviewed.Themostsignificantdistinguishingcharacteristicofalgal oilisitsyieldand,hence,itsbiodieselyield.Accordingtosomeestimates,theyield (per acre) of oil from algae is over 200 times the yield from the best-performing plant/vegetableoils.Thelipidandfattyacidcontentsofmicroalgaevaryinaccor- dancewithcultureconditions.Theavailabilityofalgaeandtheadvantagesofalgal oilforbiodieselproductionhavebeeninvestigated. BillionsofyearsagotheEarth’satmospherewasfilledwithCO .Thustherewas 2 no life on Earth.Life on Earthstarted with Cyanobacteriaand algae.These hum- blephotosyntheticorganismssuckedouttheatmosphericCO andstartedreleasing 2 oxygen.Asaresult,thelevelsofCO starteddecreasingtosuchanextentthatlife 2 evolvedonEarth.Onceagainthesesmallestoforganismsarepoisedtosaveusfrom thethreatofglobalwarming. Inthe contextofclimatic changesandsoaringpricesfora barrelof petroleum, biofuels are now being presented as a renewable energyalternative. Presently, re- search is being done on microscopic algae, or microalgae, which are particularly rich in oils and whose yield per hectare is considerably higher than that of sun- flowerorrapeseed.Algaewillbecomethemostimportantbiofuelsourceinthenear future.Microalgaeappeartobetheonlysourceofrenewablebiodieselthatiscapa- ble of meetingthe globaldemandfor transportfuels. Microalgaeare theoretically averypromisingsourceofbiodiesel. Algae are the fastest-growing plants in the world. Industrial reactors for algal culture are open ponds, photobioreactors,and closed systems. Algae are very im- portantasabiomasssourceandwillsomedaybecompetitiveasa sourceforbio- fuel.Differentspeciesofalgaemaybebettersuitedfordifferenttypesoffuel.Algae canbegrownalmostanywhere,evenonsewageorsaltwater,anddoesnotrequire fertile land or food crops, and processing requiresless energythan the algae pro- vides. Algae can be a replacement for oil-based fuels, one that is more effective v vi Preface andhasnodisadvantages.Algaeareamongthefastest-growingplantsintheworld, and about50% of their weight is oil. This lipid oil can be used to make biodiesel forcars, trucks,andairplanes.Microalgaehavemuchfaster growthratesthan ter- restrial crops. the per unit area yield of oil from algae is estimated to be between 20,000 and 80,000L per acre per year; this is 7 to 31 times greater than the next bestcrop,palmoil.Mostcurrentresearchonoilextractionisfocusedonmicroalgae to produce biodiesel from algal oil. Algal oil is processed into biodiesel as easily asoilderivedfromland-basedcrops.Algaebiomasscanplayanimportantrolein solvingtheproblemoffoodorbiofuelsinthenearfuture. Microalgaecontainoils,orlipids,thatcanbeconvertedintobiodiesel.Theidea ofusingmicroalgaetoproducefuelisnotnew,butithasreceivedrenewedattention recently in the search forsustainable energy.Biodiesel is typicallyproducedfrom plantoils,buttherearewidelyvoicedconcernsaboutthesustainabilityofthisprac- tice. Biodieselproducedfrommicroalgaeisbeinginvestigatedasanalternativeto usingconventionalcropssuchasrapeseed;microalgaetypicallyproducemoreoil, consumelessspace,andcouldbegrownonlandunsuitableforagriculture. Usingmicroalgaeasasourceofbiofuelscouldmeanthatenormousculturesof algaearegrownforcommercialproduction,whichwouldrequirelargequantitiesof fertilizers.Whilemicroalgaeareestimatedtobecapableofproducing10to20times morebiodieselthanrapeseed,theyneed55to111timesmorenitrogenfertilizer– 8to16tons/ha/year. Thisbookonalgaeenergyattemptstoaddresstheneedsofenergyresearchers, chemicalengineers,chemicalengineeringstudents,energyresourcespecialists,en- gineers, agriculturists, crop cultivators, and others interested in practical tools for pursuingtheirinterestsinrelationtobioenergy.Eachchapterinthebookstartswith basicexplanationssuitableforgeneralreadersandendswithin-depthscientificde- tailssuitableforexpertreaders.Generalreadersincludepeopleinterestedinlearn- ingaboutsolutionstocurrentfuelandenvironmentalcrises.Expertreadersinclude chemists, chemical engineers, fuel engineers, agricultural engineers, farming spe- cialists,biologists,fuelprocessors,policymakers,environmentalists,environmental engineers, automobile engineers, college students, research faculty, etc. The book may even be adopted as a textbook for college courses that deal with renewable energyorsustainability. Trabzon,TURKEY(September2009) AyhanDemirbas MuhammetDemirbas Contents 1 Introduction................................................... 1 1.1 Introduction ............................................... 1 1.2 EnergyDemandandAvailability.............................. 2 1.2.1 FossilEnergySources ................................ 3 1.2.2 RenewableEnergySources............................ 10 1.3 PresentEnergySituation .................................... 12 1.3.1 EnergyProductionandFutureEnergyScenarios .......... 12 1.3.2 FutureEnergyScenarios .............................. 13 References..................................................... 26 2 GreenEnergyFacilities ......................................... 29 2.1 Introduction ............................................... 29 2.2 BiomassFeedstocks ........................................ 30 2.3 GreenEnergy.............................................. 31 2.4 ImportanceofBiomass...................................... 32 2.5 ProductionofFuelsandChemicalsfromBiomass ............... 36 References..................................................... 46 3 Biofuels ....................................................... 49 3.1 Introduction ............................................... 49 3.2 ImportanceofBiofuels...................................... 51 3.3 Bioethanol ................................................ 54 3.4 Biodiesel ................................................. 56 3.5 Bio-oil ................................................... 59 3.6 Biogas.................................................... 61 3.7 Fischer–TropshLiquidsfromBiorenewableFeedstocks........... 64 3.8 Biohydrogen .............................................. 69 3.9 OtherLiquidBiofuels....................................... 70 3.9.1 Glycerol-basedFuelOxygenatesforBiodiesel andDieselFuelBlends ............................... 70 3.9.2 P-seriesFuels ....................................... 71 vii viii Contents 3.9.3 DimethylEther ...................................... 71 3.9.4 OtherBio-oxygenatedLiquidFuels..................... 72 References..................................................... 72 4 AlgaeTechnology .............................................. 75 4.1 Introduction ............................................... 75 4.1.1 DefinitionofAlgalTerms ............................. 76 4.2 ProductionSystems......................................... 77 4.2.1 HarvestingMicroalgae................................ 79 4.2.2 Photobioreactors..................................... 80 4.2.3 Open-pondSystems.................................. 83 4.2.4 ClosedandHybridSystems ........................... 87 4.3 ProductionCosts ........................................... 89 References..................................................... 93 5 EnergyfromAlgae ............................................. 97 5.1 Introduction ............................................... 97 5.1.1 HistoricalPerspective ................................ 99 5.2 Biofuels .................................................. 99 5.2.1 Biodiesel ...........................................102 5.2.2 Bioalcohol..........................................104 5.2.3 Costs,Prices,andEconomicImpactsofBiofuels..........106 5.2.4 EnvironmentalImpactsofBiofuels .....................110 5.2.5 CombustionEfficienciesofBiofuels ....................113 5.2.6 Bio-oil .............................................117 5.2.7 Biomethane.........................................119 5.2.8 ProductionofBio-oilandHydrogenbyPyrolysis .........120 5.2.9 AnaerobicBiohydrogenProduction.....................125 5.3 LiquefactionofAlgalCells ..................................127 5.3.1 LiquefactionofAlgalCellsbyHexaneExtraction.........129 5.4 High-value-addedProductsfromAlgae ........................131 5.4.1 SmallMolecules.....................................131 5.4.2 Polymers ...........................................132 5.4.3 High-valueOils......................................132 References.....................................................133 6 BiodieselfromAlgae ...........................................139 6.1 Introduction ...............................................139 6.2 BiodieselfromAlgalOil ....................................140 6.2.1 ProductionofBiodieselfromAlgalOils .................144 6.3 PotentialofMicroalgalBiodiesel .............................147 6.4 AcceptabilityofMicroalgalBiodiesel .........................150 6.5 EconomicsofBiodieselProduction ...........................151 6.6 ImprovingEconomicsofMicroalgalBiodiesel ..................153 6.7 AdvantagesandDisadvantagesofBiodieselfromAlgalOil .......153 References.....................................................154 Contents ix 7 Biorefineries...................................................159 7.1 Introduction ...............................................159 7.2 DefinitionsofBiorefinery....................................162 7.2.1 MainTechnicalandNontechnicalGaps andBarrierstoBiorefineries ...........................164 7.3 HistoricalPerspective .......................................164 7.4 PetroleumRefineryandBiorefinery ...........................168 7.5 RefiningofUpgradedProducts ...............................174 7.6 OpportunitiesforRefiningPyrolysisProducts...................178 References.....................................................180 8 FutureDevelopments...........................................183 8.1 Introduction ...............................................183 8.1.1 WorldTheoreticalLimitofBiomassSupply..............184 8.1.2 High-yieldEnergyCrops..............................185 8.1.3 FoodVersusFuelDelineation..........................186 8.1.4 ThermodynamicEfficiency(ExergyAnalysis) ............187 8.1.5 BiofuelUpgradation..................................187 8.1.6 CarbonCredits ......................................188 8.2 SocialandPoliticalIssues ...................................189 8.2.1 ThePromiseofAlgae:EnergySecurity..................190 8.3 EnvironmentalImpactsofBiomassProduction..................191 References.....................................................193 Index .............................................................195 Chapter 1 Introduction 1.1 Introduction Energyis defined asthe ability to do work.However,there is no conceptofforce that includes all definitions of force. For example, the forces that form light en- ergy,heat(thermal)energy,mechanicalenergy,electricalenergy,magneticenergy, etc.aredifferent.Therearemanyformsofenergy,buttheyallfallintooneoftwo categories:kineticandpotential.Electrical,radiant,thermal,motion,andsounden- ergiesarekinetic;chemical,storedmechanical,nuclear,andgravitationalenergies are typesof potentialenergy.It can exist in the formof motion.Thisis knownas kineticenergy.Themotioncanrelatetodifferentthings.Ifthemotionisofalarge object,thekineticenergyissaidtobemechanical.Ifmovingobjectsareelectrically charged,theyaresaid toformanelectric current.Ifmovingobjectsareindividual molecules,therearetwopossibilities.Iftheirmotionisorganizedintowaves,then their kinetic energy is associated with sound. If their motion is completely disor- ganized, then their kinetic energyis associated with what we call heat or thermal energy.Anotherformofkineticenergyislight(andotherformsofelectromagnetic radiation,likeradiowavesandmicrowaves).Otherformsofenergydonothavethe formof motion,butthey can cause an increase in motionat a later time. Water at the top ofa damcan spilloverthe dam.A batterycanproducean electric current whenitisconnectedtoacircuit.Fuelscanbeburnedtoproduceheat.Allofthese areexamplesofpotentialenergy. The world is presently confrontedwith twin crises of fossil fuel depletion and environmentaldegradation.Toovercometheseproblems,renewableenergyhasre- centlybeenreceivingincreasedattentiondueto itsenvironmentalbenefitsandthe factthatitisderivedfromrenewablesourcessuchasvirginorcookedvegetableoils (bothedibleandnonedible).Theworld’sexcessivedemandforenergy,theoilcrisis, andthecontinuousincreasein oilpriceshaveled countriestoinvestigatenewand renewablefuelalternatives.Hence,energysourcessuchassolar,wind,geothermal, hydro,nuclear,hydrogen,andbiomasshavebeenconsidered. A.Demirbas,M.FatihDemirbas,AlgaeEnergy 1 DOI10.1007/978-1-84996-050-2,©Springer2010