Greening'your'Biomethane' Production'Chain'

Transcription

1 Greening'your'Biomethane' Production'Chain' A best practice guide for reducing greenhouse gas emissions

2 TABLE'OF'CONTENTS' EuropeanBiomethanePotential... 3 BiomethaneSustainabilityCriteria... 4 BiofuelsandBioliquidsSustainabilityCriteria... 4 RenewableEnergyDirective... 4 oluntaryschemes... 4 BioenergySustainabilityCriteria... 5 SolidandGaseousBiomassSustainability... 5 LifecycleAssessmentofBiomethaneProduction... 6 LifecycleAssessments... 6 EuropeanUnionREDLifecycleModel... 7 PurposeofLifecycleAssessmentinBiomethaneProduction... 6 CarbonBenefitsofBiomethanePlants... 9 ModellingtheLifecycleGHGEmissionsofBiomethane REDLifecycleModelinPractice BenefitsofUsingREDLifecycleMethodology BestPractice BiomethaneProduction ReducingEmissionsthroughBestPractice MethodsofBestPractice Cultivation&Harvesting Transport&Distribution BiogasProduction BiomethaneUpgrading FutureFeedstocks CaseStudy bestpracticemethaneemissions BiomethanetheSwedishWay PolicyUpdate EuropeanCommissionUpdateonILUC

3 EUROPEAN'BIOMETHANE'POTENTIAL'' Biomethane can be used in the same efficient and versatile manner as natural gas for transportation, heat and electricity and in addition to this, the feeding of upgraded biogas, biomethane, into national gas grids offers a flexible energy solution to meet European renewable energy targets. Due to these advantages biomethane is becoming increasingly important on the political agenda and also as a business opportunity in Member States across the European Union (EU. InseveralEUcountriesincludingTheNetherlands,GermanyandAustria,theuseofbiomethanehas beeninpracticeforseveralyearsandrespectivepolicyschemesarealreadyinplace.othermember Statesarenowfollowingsuit,however,developmentsareslowandstrongsupportisstillneededdue tothecomplexityofthelongvaluechains,lackofcooperationbetweeninvolvedstakeholdersand crossbordertradebarriers. A successful European cross border biomethane market relies heavily on environmentally and economicallysustainableproductionacrosstheentirebiomethanelifecycle.inadditiontothis,the biomethane market requires support in finding solutions to market barriers, bringing together potentialbusinesspartnersandmostimportantly,thepromotionofbiomethaneintothemainstream bypositioningitontheagendaofkeyeugas/energybodies. The focus of this report is to outline the relevant sustainability criteria regarding biomethane production,themethodsbywhichthiscanbeassessedandthusevaluatemethodsofbestpracticein sustainablebiomethaneproduction. ThelastsectionofthereporthighlightstherecentchangesfromtheEuropeanCommissionregarding howmembersshouldimplementemissionsfromindirectlandusechange(iluc. 3

4 BIOMETHANE'SUSTAINABILITY'CRITERIA' BIOFUELSANDBIOLIQUIDSSUSTAINABILITYCRITERIA The rapid development of the global biofuels and bioliquids 1 market has led to concerns over the environmental,economicandsocialsustainabilityoftheindustry.asaconsequence,setsastringent criteriaforassessingthesustainabilityofbiofuelsandbioliquidshavebeendeveloped. RENEWABLEENERGYDIRECTIE TheRenewableEnergyDirective(RED 2 setsoutinarticle17,18,19andannexthesustainability criteriaforbiofuelsandbioliquids.thelegallybindingcriteriaapplyacrosstheeuropeanunion(eu anddonotallowforadditionalcriteriatobeimposedbymemberstates. All biofuels and bioliquids produced within the EU must comply with the sustainability criteria specifiedintheredinordertoreceivegovernmentsupportorcounttowardsmandatorynational renewable energy targets. This includes the delivery of the Directive s twin targets for 10% of EU transportfuelsand20%ofeuenergyneedstobesourcedrenewablyby2020. Thesustainabilitycriteriaaimstopromotebiomethaneproductioninasustainableformbyfocusing onseveralkeyareas; ReductioninGHGemissions GHG emissions savings from the use of biofuels and bioliquids to be at least 35%comparedtofossilfuels. Risingto50%,January2017. Risingto60%,January2018. Biodiversity Rawmaterialmaynotbeobtainedfromlandregarded/classedashavinghigh biodiversity(afterjanuary2008. May include: primary forest, designated nature protection areas, highly biodiversegrassland. Landofhighcarbonstock Raw material may not be obtained from land with high carbon stock (after January2008. Mayinclude:wetlandsorhighlyforestedareas. OLUNTARYSCHEMES Inordertofacilitatethesinglemarket,theEuropeanCommission(ECcanassessexistingvoluntary schemesmonitoringsustainability. The EC selection process for oluntary Schemes has been made on the compliance of the Certification Schemes (listed below and whether or not they meet the mandatory sustainability requirementsofthered.inadditiontothesevencurrentlyapprovedandrecognisedschemeslisted below member states are also able to use their own oluntary Schemes providing the EC s requirementsaremet. 1 Biofuelsmeans liquidorgaseousfuelfortransportproducedfrombiomass.bioliquidsmeans liquidsfuelfor energypurposesotherthanfortransport,includingelectricityandheatingandcooling,producedfrombiomass. 2 Directive2009/28/ECoftheEuropeanParliamentandoftheCouncilof23April2009onthepromotionofthe use of energy from renewable sources and amending and subsequently repealing Directives 2001/77/EC and 2003/30/EC. 4

5 ISCC(InternationalSustainabilityandCarbonCertification; Coversalltypesofbiomassandbiofuels; RecognitionforallcriteriaoftheRED; BonsucroEU(astandardforsugarcanebasedethanol; Focus:Braziliansugarcaneproduction; Recognition for all criteria of the RED, except provision on highly biodiverse grasslands; RTRSEURED(RoundtableforResponsibleSoy; Focus:ArgentineanandBrazilianSoyProduction; RecognitionforallcriteriaoftheRED; RSBEURED(RoundtableonSustainableBiofuels; RecognitionforallcriteriaoftheRED; 2BSvs(BiomassBiofuelsSustainabilityoluntaryScheme; Recognition for all criteria of the RED, except provision on highly biodiverse grasslands; RBSA(AbengoaREDBioenergySustainabilityAssurance; RecognitionforallcriteriaoftheRED; GreenenergyBrazilianBioethanolerificationProgramme; FocusesonBrazil; Recognition for all criteria of the RED, except provision on highly biodiverse grasslands. BIOENERGYSUSTAINABILITYCRITERIA SOLIDANDGASEOUSBIOMASSSUSTAINABILITY In order to comply with Article 17(9 within the RED the Commission was required to report on sustainabilityschemesfortheuseofsolidandgaseousbiomassforenergyotherthanbiofuelsand bioliquids.therecommendationsbroadlyfollowthecriteriaintheredfocusingonseveralkeyareas. Protectionofbiodiverseland Protectionofhighcarbonstockland GHGemissionssavings(in%termsasstatedintheRED Differentiation of national support schemes in favour of installations that achieve high energyconversionefficiencies Monitoringoftheoriginofbiomass DespiteinitialindicationsofapotentiallyEUwidebindingsustainabilitycriteriaforsolidandgaseous biomassinelectricity,heatingandcooling,thecriteriaisstillassessedsolelythroughnonmandatory voluntaryschemes. 5

6 LIFECYCLE'ASSESSMENT'OF'BIOMETHANE'PRODUCTION'' All energy systems emit greenhouse gases (GHG and thereby can contribute both directly and indirectlytoclimatechange.itisnowwidelyrecognisedthatghgemissionsresultingfromenergy generationneedtobequantifiedoverallstagesofproductioninordertomonitoremissions,andin thisinstancepromotesustainability.whileaccuratecalculationsofghgemissionsperkilowatthour (kwhareoftendifficult,soundknowledgeoflifecycleemissionscanbeanimportantindicatorfor mitigationstrategiesandidentifyingpotentialmethodsofbestpractice. LIFECYCLEASSESSMENTS A Lifecycle Assessment (LCA comprises of both environmental impacts and impacts on resource consumption,aswellascoveringtheutilisationandenduseoftheproduct.thismethodallowsevery component of biomethane production to be assessed in terms of GHG emissions and resource depletion and thus helping to evaluate the sustainability of the entire process from feedstock productiontobiomethaneinjection. LIFECYCLEASSESSMENTINBIOMETHANEPRODUCTION A LCA of biomethane production has the potential to provide several benefits for the biomethane industry: Stopstheproblemofshiftingenvironmentalimpacts Helpstominimisesecondaryeffectsifusedinconjunctionwithdesign Helpstoreduceenvironmentalpollutionandresourceuse Enablesunderstandingoftrueandtotalcosts Environmentalmanagementtechniques(includingLCAmayimproveprofitability. Biomass is increasingly becoming a priority resource to substitute fossil fuels in the energy and transportsector,asistheneedtoensuretheprocessissustainable. Figure1brieflyoutlineseachstageofbiomethaneproduction,theareasofpotentialGHGemsissions andresourceuseassociatedwitharangeofinputs. Figure1:SourcesofGHGEmissionsinBiomethaneProduction 6

7 ThelevelofGHGemissionsproducedduringbiomethaneproductionmayvaryaccordingtothescale oftheinputs(e.g.theamountofmachineryorfertiliserused,aswellasreflectingthesustainability ofthemethodsofpracticeinplace. Figure 2 provides theoretical estimates to the GHG associated with each stage of biomethane production.asillustratedinthisscenario(basedontheuseofmaizeasafeedstockcultivationisthe largest source of GHG emissions, accounting for between 1060% of total GHG emissions. It is importanttonotethatthesearepurelytheoreticalvaluesforrepresentationonly. Figure2:GHGEmissionsLifecycleAssessment Othersourcesofemissionsrelatetothebiogasproductionprocess.Themoderndesignsofanaerobic digestion (AD plants attempt to ensure the anaerobic nature of the fermentation process and minimise GHG emissions; both biogas production and biomethane upgrade are also significant sources of emissions. Emissions at these stages relate directly to the problem of methane slip (emission.ithasbeensuggestedthatamethaneslipofmorethan2%issufficient toreversethe positiveenvironmentalsavingsofbiomethanewhencomparedtootherfossilfuels. 3 Methaneslipisa key concern for a number of reasons; the chemical properties of methane enable a longer atmospheric lifetime compared to CO 2 (approximately 23 years and mean it is more efficient at trapping heat in comparison to other GHG. For these reasons there is a strong focus on reducing methaneslipthroughtheimplementationofdifferenttechnologies,thisnotonlyhasthepotentialto increase the overall sustainability of biomethane production but also minimises the impact on economicreturns. EUROPEANUNIONREDLIFECYCLEMODEL Stages of biomethaneproduction are detailed in terms of emissions by the European Union s RED LifecycleModel,asshownbelow: E feedstock =e ec +e l +e p +e td +e u e sca 3 BioGasMax. NaturemadeBiomethaneLabel,

8 E=totalemissionsfromtheuseoftheproduct e ec=emissionsfromtheextractionorcultivationofrawmaterials e l=annualizedemissionsfromcarbonstockchangecausedbylandusechange e p=emissionsfromprocessing e td=emissionsfromtransportanddistribution e u=emissionsfromfuelinuse e sca=emissionssavingfromsoilcarbonaccumulation UsingtheEUREDLifecycleModelenablesgeneratorsandotherstakeholderstoassesstheemissions associatedwithbiomethaneproductionacrossthebioenergylifecyclefromcultivationtoprocessing andgridinjection. 8

9 CARBON'BENEFITS'OF'BIOMETHANE'PLANTS' ThesustainabilityofbiomethaneplantsisdirectlyrelatedtothepotentialGHGsavingsthatbiomass feedstocksofferincomparisontootherfossilfuels.atpresent,themostcommonuseofbiogasisfor electricity generation. However, it is argued that this will not be the case in the future, as the sustainability of biogas use will have a greater impact and therefore biomethane injection will be favoured. Althoughbiomethaneproductionisamoreefficientmethodofusingbiogascomparedtoelectricity onlyproduction,duetotheeu srelativelycarbonintensiveelectricitygrid,biomethanegasinjection hasalowercarbonsavingimpactthanusingbiogasforelectricitygeneration. MaximisingtheGHGsavingsfromtheuseofbiomassdemandsthatitisconvertedasefficientlyas possibleintoheatand/orpower.modellinghasshownbiomassfeedstocksareabletodemonstratea EU Biomass Reduction 35% UK Biomass Reduction 60% EU Biomethane Reduction 35% UK Biomethane Reduction 60% Figure3:GHGEmissionsofBiogas:EUandUKTargets rangeofghgsavingsunder goodpractice conditions. InordertomeettheEUsustainabilitycriteriaonbiomassoutlinedintheRED,electricitygenerating facilities must achieve a GHG reduction of 35% or greater compared to the current European electricitymix.insomecountries,suchastheukthistargethasincreasedto60%(figure3.tomeet EUcriteriaonbiomethane,electricitygeneratingfacilitiesmustreachaGHGreductiontargetof35%, intheuk,again,increasingto60%. UsingtheREDmethodologymodellinghasdemonstratedthatADplantsareabletoachieveaGHG reduction of at least 72% for biogas to electricity production, when acting under best practice. Furthertothis,withaheatrecoveryunitsuchasanOrganicRankineCycleengine(ORC,electricity efficiencycanincreasefurtherofferingareductioninghgofover80%.forbiomethaneplantsthe expectedghgemissionsareapproximately60kg/co 2 /MWh. 9

10 MODELLING'THE'LIFECYCLE'GHG'EMISSIONS'OF'BIOMETHANE' REDLIFECYCLEMODELINPRACTICE TheREDGHGmethodologyhasbeendevelopedtocalculatethecarbonintensityandGHGemissions savings of solid biomass and biogas used for electricity and heat generation. The methodology incorporates recommendations set out by the EC. This facilitates increased understanding of the breakdown of GHG emissions between the different supply chain steps in biomethane production andincreasesknowledgeonhowfurthercosteffectiveghgreductionsmightbeimplemented. BENEFITSOFUSINGREDLIFECYCLEMETHODOLOGY TheREDmethodologyforLCAwasdevelopedforcalculatingtheGHGemissionsfromsolidbiomass andbiogasusedtogenerateheatandelectricity,andcoverseverystepfromfeedstockproduction throughtoenergygeneration.thisenablesbioenergygeneratorsandotherstakeholderstoanalyse the life cycle emissions from bioenergy using different feedstocks, production processes and transportmethods.memberstatesthatadoptthismethodologywill:! Helpbioenergygeneratorstoreportemissionsconsistentlyandfairly! FullycompatiblewiththeREDforcalculatingGHGemissions! TakesaccountofrecommendationssetoutbytheEC! FullyassesstheperformanceofcropsfeedstocksforADintermsoftargetsforimprovinglife cycleemissions. AsillustratedinFigure(4theuseoftheREDmethodologyallowsthelifecycleGHGemissionstobe calculatedforeachstageofbiomethaneproduction.figure(4usestypicaldefaultvaluesforavariety offeedstocks. Percentage of Total Emissions Cultivation & Harvesting Transport & Distribution Production of Biogas Biomethane Upgrade Biomethane Injection 0 Silage Grass Whole Crop Maize Organic Whole Crop Sugar Beet Wet Manure Dry Manure Whole Crop Wheat Maize Feedstock Figure4:PercentageLifecycleEmissionsbyFeedstock 10

11 The GHG emissions are quantified as a percentage of the total emissions related to each stage of biomethane production. As shown, all energy crops indicate that the highest proportion of GHG emissionsaresourcedfromcultivationandharvesting,representingaminimumof40%oftotalghg emissions. Whereas, using manure as the feedstock shows biomethane upgrade as the highest contributor of GHGemissions, however a greater quantity of manures and slurries will have to be processedto make the equivalent amount of biogas produced by a small amount of crop. In both cases biomethane upgrade is also highlighted as a large GHG source, being the second highest emitter forcropbasedfeedstocks. The UK Carbon Calculator developed from the RED methodology assumes the default value for methaneslipof0.01mjch 4 /MJofbiogasproduced.Thisvaluecanhowevervarydependingonthe levelofbestpracticeadopted.thiswillbeexploredfurtherlaterinthedocument. Carbon Intensity (g CO 2 eq/mjbiomethane Silage Grass Whole Crop Maize Organic Whole Crop Maize Whole Crop Sugar Beet Wet Manure Dry Manure Wheat Cultivation & Harvesting Transport & Distribution Production of Biogas Biomethane Upgrade Biomethane Injection Total "Carbon intensity [g CO2eq / MJbiomethane]" Feedstock Figure(5showsthetotalGHGemissionsintermsofcarbonintensity(gCO 2 eq/mj biomethane foreach stageofthelcaaswellasthetotalghgemissionsproducedforeachfeedstock.wholecropwheat feedstockisseentoproducethehighestlevelsofghgemissions,incontrasttousingdrymanure, whichproducesthelowestlevelsofghgemissions.thisislikelytobeduetotheuseoffertilisersin crop based feedstocks contributing a significant proportion of emissions in the harvesting and cultivationstageincomparisontomanureswhichareconsideredtohave zeroemissions. Figure5:LifecycleGreenhouseGasEmissionsbyFeedstock 11

12 ' BEST'PRACTICE 'BIOMETHANE'PRODUCTION' Predictions suggest that the global biogas market is projected to reach US$8.9 billion by the year 2017 according to a report by Global Industry Analysts. 4 Europe is still considered the dominant playerinthemarket,yetindiaispoisedtoemergeasthefastestgrowingregionalmarket.whilethis growthiswelcome,ithaspromptedaninfluxofquestionsregardingsustainabilityintheadindustry. Forthisgrowthtobemanagedsafelybestpracticemethodswillneedtobeimplementedinorderto promoteandallowsustainablebiomethaneproductiontocontinue. REDUCINGEMISSIONSTHROUGHBESTPRACTICE Greenhouse gas emissions from biomethane can be calculated based on scenarios of best and worst practice havingreviewedindustrypracticesthesehavebeeninputtedintothemodel. GHG emissions from biomethane production can be affected by a number of factors. In order to generatethebestandworstcaseswereconsideredforthefollowingparameters: Yield Moisturecontent Quantityofdigestateused Quantityofartificialfertilisersused Transportationdistanceoffeedstock Efficiencyofthebiogasdigester Methaneemissionsassociatedwithbiogasproduction Methaneemissionsassociatedwithbiogasupgrade Electricityuseforbiomethaneinjectionintothegrid Operatorsare able to use memberstate default values to calculate carbon intensity based on the values set out in the EC Report. The EC s default values for GHG savings for the various biomass feedstocks can be used in combination with the actual conversion efficiency of the plant, 5 thereby allowinguserstoinputtheirowninformation.whenusingthedefaultvaluestheusermustensure thattheyusethecorrectdefaultvaluefortheirfeedstock. Thesecondoptionistocalculatethecarbonintensitybasedon actualvalues obtainedfromindustry andoperatorexperience.iftheactualvaluemethodisused,amoreaccuratecalculationcanbemade of the carbon intensity of the biomass fuel being used. This approach also helps give a greater understandingofthelifecycleemissions. Table 1 indicates the potential difference in GHG emissions as a result of best and worst practice biomethaneproductionwiththeuseofmaizeasafeedstock.adjustingthefiguresforbestandworst practice has a substantial effect on the level of GHG emissions produced in the biomethane productionprocess.notablechangesoccurtotheemissionslevelinthecultivationandharvesting stage of production. Similarly the second largest source of emissions, biomethane upgrade, has a highly varied total emissions produced depending on the scenario, reflecting the importance of monitoringareasofmethaneslip. 4 GlobalIndustryAnalysts,Inc,BiogasPlants:AGlobalStrategicBusinessReport,April DECC,ROO2011StatutoryConsultationoftheRenewablesObligationOrder2011,July

13 Maize' ' Default' gco 2 eq/( MJ biomethane ' Best'Practice' gco 2 eq/( MJ biomethane ' Worst'Practice' gco 2 eq/( MJ biomethane ' CultivationandHarvesting TransportandDistribution ProductionofBiogas BiomethaneUpgrade BiomethaneInjection TotalEmissions Table1:GHGEmissionsLifecycleAssessmentforMaize:BestandWorstPractice Thedifferencebetweenbestandworstpracticetotalemissionsisover37gCO 2 eq/mjbiomethane, whichhighlightsthepotentialboostthatbestpracticemethodscanprovide.theseresultsarealso presentedinfigure6andtable1alongsidethebestandworstcaseghgemissionsscenariosforboth silagegrassandsugarbeet.inallcasestheworstpracticescenariosallproducedhigherlevelsofghg emissions. Carbon Intensity (g CO 2 eq/mjbiomethane Default 70 Worst Practice 60 Best Practice Silage Grass Maize Sugar Beet Feedstock Figure6:BestandWorstPracticeGHGEmissionsLifecycleAssessment Total'GHG'Emissions'' (g/mj' ' Silage'Grass' Maize' Sugar'Beet' Default BestPractice Table2:BestPracticeGHGEmissions 13

14 METHODS'OF'BEST'PRACTICE'' CULTIATION&HARESTING USINGDIGESTATE Cultivation and harvesting is one of the largest sources of GHG emissions over the LCA of biomethane.bestpracticemethodstominimiseemissionscanbeimplementedinanumberofkey areas. Research evidence is accumulating that biomethane production via anaerobic digestion provides further environmental benefits if the AD digestate is used as an alternative fertiliser for cropsandpasture.thevalueofaddigestateasanagriculturalfertiliserismeasuredbothasthecost ofreplacedfertiliseranditsseveralenvironmentalbenefits.thenutrientprofileandfertiliservalueof digestateisdependentonthefeedstockcomposition.energycropsgenerallyhavegreaterdm(dry mattercontentandmorefavourablenutrientcompositionthanmanureslurries,resultinginamore concentratedandvaluabledigestate. 6 Digestate is an easy product to handle and apply making it a successful substitute for mineral fertilisers. The quantities of nutrients that are supplied to a digester via the feedstock are nearly equal to those in the digestate. Adoption of best practice management has the potential to give direct environmental benefits from the use of digestate as a fertiliser. Such practices will result in lowergaseousemissionsintotheatmosphereaswellaslessdiffusepollutionfromsurfacerunoff andleachingthroughtheuseofartificialfertilisers. RECOMMENDATIONS Use digestate as a substitute for artificial fertiliser, digestate has a significantly reduced odourincomparisontoanimalmanuresandorganicwastes,whichcontainvolatileorganic compounds,whichproduceunpleasantodours. Avoidsprayingliquiddigestatetominimiseammoniaemissions.Directinjectiontechniques shouldberecommendedwherebythedigestateisconcentratedoverasmallerareaofsoil withoutdisruptingthesoilstructure. NITROGENINHIBITORS Nitrogenisregardedasthemostyieldlimitingelementincropproductioninmostsoils,butisalso the most easily lost nutrient from the soil. The amount of nitrogen oxide emitted is increasing, emissionsfromagriculturecurrentlyaccountforapproximately68%ofthis,mainlystemmingfrom the decomposition of nitrogen compounds in the soil. The nitrogen within fertiliser is crucial to ensuring agricultural productivity, however, when excess nitrogen remains in the soil, in certain conditionsitisconvertedton 2 OandisreleasedintotheatmosphereasaharmfulGHG. 7 Nitrification istheprocessthatconvertsammoniumnitrogentonitratenitrogeninthesoil.nitrogeninhibitors retardtheprocess,therebyincreasingtheproportionofammoniumnitrogenstoredinthesoil. 6 Mokry,etal.2008.Fertilizationofarablecropswithdigestateofagriculturalbiogasplants.Landwirtschaftliches TechnologienzentrumAugeustenbuerginKarlsruhe. 7 CommitteeonClimateChange.Agriculture,EmissionsfromAgriculture,November

15 RECOMMENDATIONS Applyingnitrogentransformationinhibitorsispromisinginreducingnitrousoxide(N 2 Oin botharableandpastoralsoils,withsomereportsindicatinga1029% 8 reductioninemissions throughreducingnitrateproductionbyslowingthenitrificationprocess. TRANSPORT&DISTRIBUTION Purpose Grown Crops are an important feedstock for anaerobic digestion (AD plants, both mixed with farm and other organic waste and on their own. As well as offering a high level of energy generation, they can make a significant contribution to the economic and environmental sustainability of farming. The role of purpose grown crops in increasing the sustainability of agricultureinconjunctionwithuseasafeedstockcanbeadelicatebalance. Bestpracticemeasuresfocusonusinglocallysourcedcropbasedfeedstockswhichdonotimpede upon food production by fitting into the normal crop rotation and working as a break crop providingadditionalfinancialbenefitsforfarmersaswellaspromotingbiodiversityandboostingsoil conditions on marginal lands previously unsuitable for food production. In addition to this, biogas systems are very flexible; feedstocks often include plants that are not used directly for human consumptionincludinggrass. RECOMMENDATIONS Transportation distance should be minimised as much as possible. Digestate removal and applicationshouldalsobeaccountedfor. BIOGASPRODUCTION METHANESLIP Methane is an essential component of biogas, however it is an area of potentially significant emissions. Emissions of methane may result in worsening the positive climate balance of biogas production and use. Methane emissions from biogas plants occur if unburned biogas escapes into atmosphere(diffusionthroughfoils,leaks,highpressurecutoffvalves,enginesfailuresetc.andif fermentationresiduewhichhasnotcompletelydecomposedleavestheclosedsystemofthebiogas plant(fermentationresiduetanknotgastightcovered.greaterrequirementshavebeenputinplace forbiogasplantssothatmethanecannolongerescapeintotheatmosphere.thisisachievedwith additional technical measures, such as double membrane roofs on the fermentation tanks, gas measurementandanalysisdevices,acoveredendtankforfermentationresidueandfermentation residuedistributiononfieldsusingdraghoses,aswellasthefrequentcheckingandmeasuringofthe methaneslip. 8 istosoetal.2012.effectofnitrogeninhibitorsonnitrousoxideemissionsandpasturegrowthfollowingan autumnapplicationinavolcanicsoil.chileanjournalofagriculturalresearch,72(1. 15

16 RECOMMENDATIONS Methane slip detection system should be implemented during the operational life of the plant. This requires a methane detection camera to assess possible leaks from the fermenter,piping,jointsandvalves. Methane slip detection should be carried out on an annual basis to ensure any plant deteriorationdoesnotincreasemethaneemissionsfromtheplant. DIGESTATESTORAGE Digestateisproducedthroughouttheyearandmustthereforebestoreduntilthegrowingseason, which is the only appropriate time for its application as a fertiliser. Similarly, to manure, if liquid digestateisstoredinopentanks,ammoniaandmethanegases(residual biogas aregivenoffand thereforemakeitapotentialsiteofghgemissions.bestpracticemeasuresfocusontheuseofa protective layer over the liquid digestate to reduce emissions. Some European countries with a developed biogas sector (e.g. Germany, Denmark and Austria now have financial incentives to establishcovereddigestatestores,withthemainobjectiveofreducingemissions. RECOMMENDATIONS Coveredstorageofliquiddigestate.ThisisnowmandatoryintheUKinordertomeetthe National Endof Waste criteria (PAS110. This will reduce any potential methane slip from thedigestateprocess.insomecasesnearly10%ofthetotalbiogasproductionisgenerated inthedigestatestore. HEATUSAGE Currently,whilstthereissomeusefortheheatthatiscreatedintheADprocess,wherebiogasisused for electricity it is the norm that a large proportion of the heat is dumped as a result of there generallybeingconstraineddemandintheimmediatevicinityoftheplant.biomethaneproduction countersthisprobleminsomerespectthroughtheupgradingofbiomethanetoinjectablestandards. Thisallowsgastobeinputintothenetworkandaconsummateamountofgastobetakenoutat anotherlocationtobeburnedinachpwherethereisausefortheheat.however,inadditionto producing biomethane for grid injection, many biogas plants use it on site to produce heat or electricity.farmbasedbiogasplantsforinstanceusetheproducedbiomethanetocovertheirown energyneedsbutmayalsosellsurpluselectricitytothegridorsuppliers. Bestpracticemethodspromotetheuseofallavailableheat,whetheritisusedforlocalheatingor remote heating (via district heatingnetworks.the excessheatcanbedistributedtomoredistant premises, either directly through gas pipes or indirectly through district heating networks. Alternatively excess heat may be used for the production of additional electricity, although this is comparativelynew.thistakesplaceinorc(organicrankinecycleplants.theyallowanincreasein theoverallelectricalefficiencyofconversionintoelectricitybyasignificantamount.owingtothestill highadditionalinvestmentcoststhisoptionisnotablysuitableforlargerbiogasplants. 16

17 BIOMETHANEUPGRADING METHANESLIP Biogasupgradingandtheproductionofbiomethaneisastateoftheartprocessofgasseparation.A number of different technologies to fulfil the task of producing a biomethane stream of sufficient qualitytoactasavehiclefuelortobeinjectedintothenaturalgasgridarealreadycommercially available and have proven to be technically and economically feasible. Nevertheless, a small percentageofmethaneislostduringtheupgradestage. Intensive research is still in progress to optimize and further develop technologies to minimise methane slip. A range of different technologies currently exist each with their own specific advantagesanddisadvantagesandthisreviewshows,thatnotechnologyistheoptimalsolutionto eachandeverybiogasupgradingsituation.therightchoiceoftheeconomicallyoptimaltechnologyis strongly depending on the quality and quantity of the raw biogas to be upgraded, the desired biomethanequalityandthefinalutilisationofthisgas. RECOMMENDATIONS Methane slip from biomethane upgrade plants can be up to 12% of the total methane production selectingatypeofupgradetechnologythatgeneratesthelowestamountof methaneslipiscrucial. o Biogaspartner 9 reportonbiogasgridinjectioningermanyandeuropeprovidesan overviewofmethanelossfromdifferentupgradetechnologies. Posttreatmenttechniquescanbeimplementedtodealwithmethaneslip,theseinclude: o Regenerativethermaloxidizer o Recuperativethermaloxidizer o Biologicaldemethanation. 9 Biogaspartner ajointinitiative.biogasgridinjectioningermanyandeurope Market,Technologyand Players. 17

18 FUTUREFEEDSTOCKS Ideallybiogasproductionwouldbenefitfromaconsistentmixoffeedstockmaterials,choppedand blended to ensure optimum methane yield. A base feedstock from break crops, or energy crops grown as part of a farm rotation, is an ideal solution for farmers and helps provide an alternative incomestreamalongsidestandardcombinableandcommoditycrops.thereareseverallowriskcrops e.g.grassandwholecropcereals,whicharewellsuitedtobiogasproduction,howevertheiryields/ha donotmatchthoseofcommonfeedstockssuchasmaizeorbeet.thebiogasindustryisalsoworking on new crops to substitute standard feedstocks for AD. These crops offer a number of benefits including;enhancedbiodiversity,lowerfarminginputsandhighbiogasyields. WILDFLOWERMIXES Wildflowersarebeingassessedintermsoftheirecologicalandenvironmentalbenefits.Theycanbe usedonbordersandmayacttoenhancebiodiversitywhenmixedwithmaize. PERENNIALCROPS SilphiumPerfoliatum(CupPlantisanexampleofaperennialcrop,whichcanbegrownonpooror marginalland.croptrialshaveshownsignificantbiodiversitybenefitsforinsetsandotherwildlifeas wellasprovidingarichmixtureofvegetation. PERENNIALGRASS Perennialgrasscanalsoprovideabiogasoutputwithminimallanddisturbance.Theyhavealowcost ofsupplyandthebiodiversitybenefitsmakethisanattractivefuturefeedstock. LUCERNE Lucereneisafloweringspeciesofferingahighbiogasyieldandsignificantenvironmentalbenefits postharvest.theplanthasahighdroughtresistance,whilstalsobeingveryefficientattakingin liquiddigestateasfertislier. SZARASIGRASS Szarvasigrassisaperennialenergycropthatisabletoproducebiogasyieldscomparableto feedstockssuchasmaize. In order to meet future sustainability criteria for biomethane systems, it will be crucial to demonstratesystemsdonotnegativelyaffectcurrentfoodproduction.thisisofspecialrelevance regardingfuturebiogasproductionfromenergycropscultivatedonarablelandandinthepotential implementationofassessmentsofindirectlandusechange(iluc. ' 18

19 CASE'STUDY' 'BEST'PRACTICE'METHANE'EMISSIONS' BIOMETHANETHESWEDISHWAY The utilisation of biogas as vehicle fuel has been successfully implemented in several European countriesforyears.insweden,biogasvehiclefuelhasbeendevelopedinregionssuchasstockholm andwestregion(göteborg,whilstsimultaneouslymethodsofbestpracticehavebeenpromotedto counter the large potential source of methane emissions in biomethane upgrading and biogas production. 2007oluntaryAgreement, Frivilligtatagande inordertoestablisha systematicapproachtoquantifyandminimisemethaneemissions. OLUNTARYAGREEMENTDETAILS The oluntary Agreement system encompasses all parts of the biogas production: from storage of substrate,pretreatmentprocesses,mixing,digestion,postdigestionandstorageofdigestateatthe plant.emissionsduringtransport,storageonfarmsorspreadingofdigestatearenotincluded.the sourceofemissionsmonitoredinclude: entilation,mixingtanks,digester,digestatestorage TheAgreementalsoencompassesthebiogasupgradeprocess.TheAgreementstartswhengasenters the building containing the upgrading equipment and ends when the gas is cleaned, dried and odorized. Emissions during transport of the upgraded biogas, compressed, propane addition, gas storageoremissionsatfillingstationsarenotincluded.sourceofemissionsinclude: OffGas,entilation,Instrumentforgasanalysis TheoluntaryAgreementconsistsofthreemainparts: Quantificationeverythreeyears measurementandcalculations Systematicemissionssource classificationplans Leakdetection recommendedmonthly TheAgreementisbaseduponoperatingstaffattendinganemissionscourseprovidedbytheSwedish WasteAssociation,furthertothis,aclassificationplanismandatoryforallBiogasPlantsdescribing wheresystematicemissionsmaybeexpectedaswellascarryingoutleakdetection. RESULTS TheIEA 10 BioenergyReportassessed18biogasplantsand20upgradingplants,theresultsshowed considerabledifferencesinmethaneemissionsfromtheplants.ithasbeenreported 11 reportedthat methaneemissionsfellforbothbiogasproductionandbiogasupgrading. BiogasProduction MethaneSlip BiomethaneUpgrade MethaneSlip Loss7.5% Loss<0.1% Loss12% Loss7% Loss2% 10 IEA, Biogas Sustainability, The Swedish oluntary System for control of methane emissions, May SP Technical Research Institute of Sweden, Nordic Biogas Conference

20 POLICY'UPDATE' EUROPEANCOMMISSIONUPDATEONILUC Europeanenergyandenvironmentallegislationhasdevelopedmarkedlyoverthelastfiveyears.The REDDirective2009/28/ECfocusesonthepromotionoftheuseofenergyfromrenewablesources. Thekeymandatorytargetsfor2020remain: 20%ofenergytobesourcedfromrenewables 10%ofEUtransportfuelstobesourcedfromrenewables TheFuelQualityDirective(FQD98/70/ECrequiresfuelsupplierstoreduceby31December2020the lifecycleghgemissionsperunitofenergyfromfuelandenergysuppliedbasedona2010baseline by 6%. For biofuels to count towards the 6% reduction target, they must also comply with the previoussustainabilitycriteria. Bothdirectivesincludecriteriaongreenhousegassavingthresholds,howeveremissionsassociated with indirect land use change (iluc were not previously subject to reporting under previous legislation,however,bothdirectivesdidincludeanobligationtoreviewtheimpactofindirectland usechangeongreenhousehasemissionsassociatedwithbiofuels. AMENDMENTSTOTHEFUELQUALITYDIRECTIE98/70/EC TheCommissionhasrecentlyreleasedfurtherlegislationtominimisetheclimateimpactsofbiofuel production.thecommissionareproposingthatthegreenhousegasemissionssavingthresholdfrom the use of biofuels taken into account for the new installations shall be at least 60% for biofuels productionprocessesstartingoperationafter1 st July2014. TheCommissioniskeentoimplementthisincreaseinCO 2 reductiontargetasitbelievesitwouldan effectivewayinreducingindirectlandusechange(ilucasitwouldleadtothereplacementofthose biofuels with estimated high ILUC emissions (such as vegetable oils by those with estimated low emissions(suchascereals,sugarsandadvancedbiofuels. It is proposed that members will now also be obliged to include indirect landuse change (ILUC factorsinreportingbyfuelsuppliers.thecommissionhassettypicalvaluesforilucemissionswhich producersshouldincludewhenaccountingthelifecycleghgemissions.thevaluesareshowninthe tablebelow. Fuelsuppliersshallby31MarcheachyearreporttotheauthoritydesignatedbytheMemberState, the biofuel production pathways, volumes and the life cycle greenhouse gas emissions per unit of energy,includingindirectlandusechangeemissions'setoutinannexmemberstatesshallreported thesedatatothecommission. 20

21 AMENDMENTSTOTHEREDDIRECTIE2009/28/EC For compliance with target referred to in first paragraph, the maximum joint contribution from biofuelsandbioliquidsproducedfromcerealandotherstarchcrops,sugarsandoilcropsshallbeno more than 5%, the estimated share at the end of 2011, of the final consumption of energy in transportin2020,theremainingtocomefromadvancedbiofuels(waste/agriculturalresiduessuchas straw. UndertheamendedRED: BiofuelsproducedfromfeedstockslistedinPartAofAnnexIX(e.g.algae,mixedMSW,but notseparatedhouseholdwasteshallbeconsideredtobefourtimestheirenergycontent. BiofuelsproducedfromfeedstockslistedinPartBofAnnexIX(e.g.usedcookingoil,animal fats,nonfoodcellulosicmaterialshallbeconsideredtobetwicetheirenergycontent. Renewableliquidandgaseousfuelsofnonbiologicaloriginshallbeconsideredtobefour timestheirenergycontent. ToprovidemarketincentivesforbiofuelswithnoorlowILUCemissions,andinparticularthe2 nd and 3 rd generation biofuels produced from feedstock that do no create an additional demand of land, including algae, straw and wastes, as they contribute more towards the 10% renewable energy in transporttargetofthered. These new measures are to promote biofuels that help achieve substantial emission cuts, do not directlycompetewithfoodandaremoresustainableatthesametime.thecommissionconsiders thatintheperiodafter2020biofuelsshouldonlyreceivefinancialsupportiftheyleadtosubstantial greenhousegassavingsandarenotproducedfromcropsusedforfoodandfeed. 21