anaerobic digestion€¦ · • power generation via chp engine • if high in h2s, biogas...
TRANSCRIPT
AnaerobicDigestionBiogasfromHeatusingFoodProcessingWaste/AgResidues
BioenergyAustraliaBiogasWorkshops
PresentationContent
AnaerobicandEnergy/NutrientRecoveryTechnologiesinWasteManagement
• IndustrialAnaerobicWastewaterTreatment• Anaerobicsludgedigestionandco-digestion• WastetoEnergy• NutrientRecovery
WhyAnaerobicDigestion?ApartfromtheEnvironmentalbenefits!
• Additionalrevenuefromreducingwasteorprocessingotherswastes
• Carboncreditsifitisfromasinglesourceandavoidslandfill
• Freefuelforheatandpower
• Utiliseexistinginfrastructurebyreconfiguringmunicipaldigesterstoprocessexternalstreams
AnaerobicDegradationPathwayTypeofsubstrateaffectspathwayandtreatmentprocess
+ NH4 + PO4 + H2S
OrganicWaste
Liquid
Dissolvedorganics- Brewery- PulpandPaper- Beverage
Tradewastecharges:Onsite
treatment
Tradewaste,sludgedisposal
chargesTreatment/Land
fill
Landfill Composting,various
Particulatesolids
- Slaughterhouse- Dairy- Manyfoodwastes
Solid
- Householdwaste- RestaurantWaste- GardenWaste- WAS- Slaughterhouse
Manureetc.
Slurry
Advantages-ChallengesAnaerobicDigestion
Advantage Challenges/Byproducts
Biogasproductionwith50-80%methane NH3andPO4release
0.43m3biogas/kgCOD removed H2Sproduced preferentially
0.1– 1.5m3biogas/kgVS Highlydependentonsubstrate,drives technologyselection
IndustrialAnaerobicWastewaterTreatment
Anaerobictechnologyisacceptedgloballyasthebestcarbonremovaltechnologyforconcentratedindustrialwastewaters
• BreweryandBeverage• PulpandPaper•ManyFoodindustries• DistilleryandFermentationindustry• Somechemicalindustries
AnaerobicWastewaterTreatmentSystemsAvailable
Lowrate
• VolumetricLoadingRate(kgCOD/m3.d)•AnaerobicLagoon 0.5-1•HighRateAnaerobicLagoon(HRAL) 1-2•CompletelyMixedDigesters 1-8
Mediumrate
•AnaerobicFloatationReactor(AFR) 3- 8•Upflow AnaerobicSludgeBlanket(UASB) 5-15•AnaerobicMBR 4-10
HighRate• InternalCirculationReactor(IC) 18-50
IndustrialAnaerobicWasteWaterTreatment
CUB Yatala Brewery BIOPAQ® UASB
Smiths water reuse BIOPAQ® IC + MBBR + MF + RO
Visy Paper BIOPAQ® IC + aeration + Thiopaq®
Toohey’s Brewery Biopaq® IC + MBR
Castlemaine Perkins XXXX brewery Water
reuse Biopaq® IC + Circox + MF + RO
Anaerobic MBR
Biogasutilisation
• Feedintosteamorhotwaterboilers(H2Supto2000ppmsustainableifcarefullymanaged– moreinfoprovidedincasestudy)• PowergenerationviaCHPengine• IfhighinH2S,biogaspre-treatmentrequired,evenforflaring• Siloxanesimportantformunicipal/co-digestionapplications• Typicalsitecanoffsetsiteheatingrequirementsby20-50%• Sitebiogasstoragegenerallyimpractical
HydrogenSulphidetreatment• Varioustechnologies,selectiondependentonflowrateandconcentration• Biological(Thiopaq)– GoodforextremelyhighH2Sconcentrations(1-2.5%ormore).Produceselementalsulphurcake
• Ironsponges– Goodformediumconcentrations(1,000– 10,000ppm).Regeneratedwithoxygen,mediareplacedperiodically.
• Ironoxideintroductionintodigester,combinedwithmicroaeration –Goodforlowratedigestion.Ironcontinuallyaddedtodigester
• Activatedcarbon– goodforfinalpolishingoflowconcentrations.Carbonfrequentlyreplacedatmoderateconcentrations.
Activated Carbon filterMedia Changeout
Iron SpongeMedia Changeout
Thiopaq scrubber
PowergenerationviaCHPengine• Efficiencyofapproximately40%,heatrecovery40-50%• Sulphurcontentextremelyimportantforlongtermreliability• H2Spre-treatmentusuallyviachillingthenactivatedcarbon• CHPmaintenancecosts– approximately4cperkWhr• Recoveredwasteheatutilisedinhotwaterlooptoheatdigesterorincomingfeed• Smallboosterfantoincreasepressure• Engineisalargesparkignitionengine,consumesoil
CastleHill,Sydney
Coombabah,GoldCoast
Sandgate,Brisbane
MunicipalAnaerobicCo-digestion
• DesignonVolatileSolidsloadingbasis,notCODorhydraulicretentiontime
• Organicmaterialdestruction:55-65%(solidsoutislessconcentratedthatsolidsin)
• Advantage:• Destructionoforganicmaterialwithminimalenergyrequirement
• Treatmentplantcanbeenergypositivewithadditionofexternalsubstrates
• Biogasusedforpowerandheatingofbiomass• Utiliseexistinginfrastructure(sitelocation,assetfordigestate treatment)
• Disadvantage:• AmmoniaandPhosphorusrelease(10-20%oftotalNloadinsewageplant),highernutrientloadifimportingsignificantnutrientquantities
Yarra ValleyWater,Melbourne
WastetoEnergyConcept
Manure OrganicIndustrialWaste
Biogas
ElectricityProduction
HeatHeatisaby-productoftheelectricityproduction
ElectricityTheCHPproduces
electricitywhichcanbeuseddirectlyorputinto
thegrid
GasUpgrading
FuelAfterupgradingbiogascanbeusedasCNGin
cars
GasGridThegascanbeput
directlyintogasgridandthebeusedtopowerhouseholdsorindustry
FoodWaste
WastetoEnergy
Underconstruction- YarraValleyWater,WastetoEnergyFacility– 100Tonnesperday
BiochemicalMethanePotential(BMP)Essentialtooltoevaluateprojectpotential
Alsotestthebiogasqualityanddigestate concentration!
WastetoEnergyKeyConcepts
• Revenue- Gatefees/CarbonCreditsforavoidinglandfill• Reducedrelianceongridpowerbysubstitution(FeedintariffsareminimalinAustralia)• Digestate – ideallyappliedtolandinacontrolledmannerasafertiliser.Considerrequirementforpasteurisationdependingonfinaluseandlocalbiosolids guidelines• Controlthefeed– knowhowmuchofeachsubstrateyouareadding.It’snotawastewaterplant!• Co-digestion– upgradewastereceival,feedandmixingsystemstocopewithsubstrateswithfeedconcentrationsof10-20%VS.
NutrientRecoveryTechnologiesTreatmentofliquidstreamafterdigestate dewatering
• Crystalactor®- PhosphaterecoveryasStruvite• Anammox – Lowenergyammoniaremoval
Crystalactor®• Crystallizationinfluidisedbedpelletreactor• Removalofphosphateasstruvite(Magnesiumammoniumphosphate)• Reagents– NaOH +MgCl2orMgO• pH9-10optimal• UseasMAP/DAPfertiliseralternative
LowEnergyNitrogenRemoval:Anammox®
OneStepANAMMOX®Process(InGranularSludge)
• Powerconsumptionreducedby~60%
• Noadditionalcarbonsourcerequirement
• TypicallyAverageNH4removal>90%
• CO2 emissionreducedby~90%
• Verylittleexcesssludgeproduction
• Stableandproven
• NofullscaleinAustraliaasyetbutvariouspilotsareunderway
WastewaterandWastetoEnergyProjects–
Keytakeaways
• Scaleisimportant– smallisolatedplantswithlowpowerandlandfillcostsarerarelyeconomic.Considerworkingtogetherwithotherproducersintheareatosharecostsandsavings.• Locateplantwherepowerandheatdemandsarehighwiththeabilitytoprocessdigestate• Transportcanbecostly– considersitebaseddewateringofsubstratestohighfeedconcentrationsiftransportinglongdistances• Knowwhatyourpotentialwastesourcesare– quantities,compositionandpotentialbiogasyieldtosupportbusinesscase
Futureopportunitiesandvision
• Householdfoodwaste- 4,000,000tonnesperannuminAustralia.450,000garbagetrucksperannum(www.foodwise.com.au)• Rolloutdedicatedhouseholdfoodwastebins– differenttogardenwastewhichiscurrentlycompostedorincinerated• 2weeklycollection(withheavysealedlidandodourcontrol!)• Plasticandimpuritiesareinevitable– howtoprocesseconomically?
• Processedatwastetransferstationtode-packageplastic,removebones/solidsetc.
• Tankered tonearbydigestersforenergyproduction
• Reduceduplicationofreceival/processinginfrastructure
HeatandPower
Centralisedprocessingfacilities
Howtochooseatechnologysupplierand/ordeliverypartner?
• BiogasandanaerobicdigestionindustryisrelativelysmallinAustralia.Manyclaimsandglossywebsites.• Keybackgroundchecks:
§ ABNlookup– howlonghavetheybeeninbusiness?Willtheybeinbusinessin5yearstimetosupporttheproject?Technologysupplierorjustabuilder?
§ Understandingofrelevantlegislation(ESV/QLDGasAct/NSWFairTradingetc.requirements).TypeBdevices.Hazardousareas.
§ Pastprojects,relevantlicensestooperatebusiness,builderslicence,PIinsurancesetc.
§ GoogleStreetView– dotheyhaveabusinesspremises?§ Pastprojectsandreferences§ Relevantaccreditations(ISOetc.)
ThankYou
• Pleasecomeandsayhelloafterwards!
• Anyquestions/enquiries- Digestionequipment,biogastreatment,CHP
engines,wastewatertreatment,turnkey
projects