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Biogasupgrading–atechnicalreview
Kers6nHoyerKualaLumpurMay26th2016
Presenta6onofmyself• Educa&on:
– M.Sc.ChemicalProcessEngineering– PhDChemicalProcessEngineering,Produc&on
ofethanolfromso<wood
• Work:– ProcessEngineer,ProcessManageratMalmberg
Water,biogasupgradingandwatertreatment2014-2016
– ResearchAreaDirectorTransporta&onandFuelsatEnergiforsk,theSwedishEnergyResearchCentresinceFeb2016
Dr. Kerstin Hoyer [email protected]
Presenta6onofEnergiforsk
WhowasSGC?• SGC–theSwedishGasTechnologyCentre
• Vision:Catalyzingenergygasdevelopmentforsustainablesolu&ons
• Mission:– ReferencepointforgasresearchinSweden– Coordinateresearchanddevelopmentintheareaofgastechnologywith
focusonrenewablegases– Supportforcommercializa&onofsustainabletechnicalsolu&ons
WhoisEnergiforsk?• Researchareas:
– Transporta&onandfuels– Energyintheforestindustry– Fuelbasesproduc&onof
electricityandheat– Districthea&ngandcooling– Electricitynets,windand
solarelectricity– Waterpower– Nuclearpower– Energysystemsandmarkets– Energyuseincl.
transporta&on
Reportsonbiogasupgrading
• WaterscrubberandPSAmaintechnologies
• Aminescrubberstarttotakesignificantmarketshare
• Membraneupgrading,organicphysicalscrubbersandcryogenicdis&lla&onconsideredupcomingtechnologies
• ”Biogasupgrading–atechnicalreview”
• Energiforsk2016:275
Content• Report”Biogasupgrading–atechnicalreview”:
– Biogasupgradingtechniques– Comparisonbetweenbiogasupgradingtechniques
• Impuri&es• Cost(investment,opera&onal)
– Gastreatment,removalofimpuri&es– Productgasquality(requirementsindifferentEuropeancountries)– Differentusesofproductgas,biomethane– Differentusesofcarbondioxideasabyproduct
Content• Report”Biogasupgrading–atechnicalreview”:
– Biogasupgradingtechniques– Comparisonbetweenbiogasupgradingtechniques
• Impuri6es• Cost(investment,opera6onal)
– Gastreatment,removalofimpuri&es– Productgasquality(requirementsindifferentEuropeancountries)– Differentusesofproductgas,biomethane– Differentusesofcarbondioxideasabyproduct
IEATask37,sta&s&csonopera&onalbiogasupgradingplantsamongIEATask37membercountries,datafrom2015
Biogasupgrading,plantsinopera6on2015
Biogasupgradingplantsover6me
Biogasupgradingtechniques• Pressureswingadsorp&on(PSA)
- CO2andCH4adsorbdifferentlyonasurfaceatdifferentpressures.
• Waterscrubber• Aminescrubber• Organicphysicalscrubber
- CO2andCH4dissolvedifferentlyinsolventssuchaswater,aminesandorganicsolvents.
Organic physical scrubber in Wolfshagen, Germany from BMF Haase
Biogasupgradingtechniques• Membranesepara&on
– CO2passesthroughasemipermeablemembranewhileCH4doesnot.
• Cryogenicupgrading– Dis&lla&onofCO2andCH4at
lowtemperatures.
Layout av membrananläggning från EnviTec
• Exceptmethaneandcarbondioxide:
• Theamountofthesedependonthesubstrate…– MoreVOCinbiogasfromhouseholdwaste/foodwaste– Moresiloxanesinbiogasfromsewagesludge
• …aswellasopera&onoftheanaerobicdiges&on– LessH2Swithdosageofironchlorideorironoxide
Whatcomesontothebiogasupgradingprocess?
H2S H2O
H2 O2 N2
Volatile organic carbon (VOC)
siloxanes
Gascleaning• Desulphuriza&on• Siloxaneremoval• Ammoniaremoval• Oxygenremoval• VOC/BTEXremoval• Methaneremovalinsidestreams• Importanttoconsiderthesequenceofthesepurifica&onmethods!• Gascleaninginrawgas,productgasorsidestream(stripperair,CO2
stream)?
Wheredothesecompoundsgo?
Waterscrubber• Biogaspressurized• Absorp&oncolumn:CO2dissolvesin
thewater• Biomethanedried• Flashcolumn• Desorp&onwithair:CO2desorbs
fromthewaterwhichisrecycled.
• H2S,NH3→stripperair,waterbleed• VOC→gascondensate,stripperair• O2,N2→productgas/biomethane• Dryingofproductgasneeded• TracesofCH4instripperair
Waterscrubber
Water Scrubber VOC, H2S
O2, N2
Product gas
Stripper air NH3
Make up H2O
H2O bleed
H2S
Aminescrubber• Absorp&oncolumn:CO2reactswith
amineandistransferredtothesolu&on
• Desorp&onwithheat• Biomethanedried• Worksatlowpressure.
• H2S→CO2stream(AthighH2Sconcentra&onsintherawgas,apolishfilterintheproductgasmaybeneededforaminescrubbers.)
• VOC,NH3→gascondensate,CO2stream• O2,N2→productgas/biomethane• Dryingofproductgasneeded• VerypureCO2canbeproduced.
Aminescrubber
Amine Scrubber H2S, NH3
O2, N2, H2
Product gas
CO2 stream VOC
Condensed gas
H2S
Organicphysicalscrubber• Biogaspressurized• Absorp&oncolumn:CO2dissolvesin
theorganicsolvent• Biomethanemayneeddrying(hasa
dewpointaround-20˚Cat1bar(a)).• Desorp&onwithair:CO2desorbs
fromthesolventwhichisrecycled.
• H2S,NH3,→stripperair• VOC→gascondensate,stripperair(WaterinsolubleVOCsare
concentratedinthesolventandcanberemovedbyanaddi&onalcleaningstep.)
• O2,N2→productgas/biomethane• Productgaswillhaveadewpointaround-20˚Cat1bar(a).• TracesofCH4instripperair
Organicphysicalscrubber
Organic physical scrubber
O2, N2, H2 VOC, H2S,
NH3
Product gas
Stripper air
PSA–pressureswingadsorp6on• Biogaspressurized• Adsorp&oncolumn:CO2retained• Pressurereleasedwhencolumn
saturated→CO2released• Severalcolumnsneededfor
con&nuousopera&on• Columnsfilledwithac&vated
carbon,zeolites,silicagelsorcarbonmolecularsieves(CMS)
• H2S,VOC,NH3,O2,N2→CO2streamBUTH2Sneedstoberemovedinpretreatmentduetoirreversiblebindingtotheadsorbent!AlsoVOCandNH3needtoberemovedinpretreatment.
• H2→productgas/biomethane• Nodryingofproductgasneeded
PSA–pressureswingadsorp6on
PSA
H2
VOC, H2S, NH3, O2
Product gas
CO2 stream N2
Membranesepara6on• Biogaspressurizedto10-20bar(a)• Membrane:CO2passesthrough
themembranetothepermeateside,CH4retainedontheretentateside
• Severalmembranestepstoop&mizeproductqualityandminimizemethaneslip
• H2S→CO2stream,significantamounttoproductgas(commonlyremovedinpretreatmenttoavoidacidcondensa&ononmembranes)
• N2,VOC→productgasBUTcertainVOCsdamagethemembranefiberandVOCsarecommonlyremovedinpretreatment
• NH3→gascondensateinpretreatmentdrying• O2→CO2streamandproductgas• Nodryingofproductgasneeded• Mostmembranessensi&vetoliquidwater,oilandpar&cles
Membranesepara6on
Membrane
O2
NH3, VOC, N2
Product gas
Permeate (CO2-stream)
H2S, H2O
H2S
Dataforspecificinvestmentcostandenergyconsump&oncollectedfrombiogasupgradingsuppliersforastandardcase.
Comparisonoftechniques
Raw gas specifications Product gas requirementsPressure: 20 mbar(g) > 4 bar(g)M e t h a n e concentration 60 vol% > 97 vol%
S u l p h u r concentration 200 ppm H2S < 20 mg/Nm3 (excl. odorisation)
W a t e r concentration Saturated with water at 40 ˚C Dew point -10 ˚C at 200 bar(g)
O t h e r requirements
Max. 0.1 vol% O2 and 0.4 vol% N2, no siloxanes, max. 100 ppm NH3
Also: 1% methane slip, containerized solution, no heat recovery, annual average
Comparisonoftechniques• Investmentcost(euro/(Nm3rawgas/h)) • Lower specific investment
cost with higher capacity, especially above 1000 Nm3/h.
• Distribution between
suppliers but no general trend concerning techniques.
• Largest distribution between
suppliers at low capacities. • Economy of scale most
dominant for membranes at low capacities and for scrubbers at higher capacities. Specific investment cost for biogas upgrading, data from different suppliers.
Comparisonoftechniques• Energyconsump&on
– 0,2-0,3kWh/Nm3biogasforalltechniques(electricityexceptforaminescrubberswhereelectricityconsump&onislowerbutalsoheatisneeded)
– Nosignificantdifferencebetweentechniqueshasbeenshownbythecollecteddata.
• Methaneslip
– Amountofmethanewhichisfoundinsidestreamsandthisnotpresentintheproductgas(%ofmethaneintherawgas)
Methane slip
Pressure swing adsorption (PSA) 1-1.5%
Water scrubber 1%
Amine scrubber <0.1%
Membrane separation 0.5%
Organic physical scrubber 1-2%
Cryogenic upgrading No data
Thanksto…Referencegroup:• AirLiquide• Ammongas• Biofrigas• BMFHaase• Carbotech• DMT• DVGW• Envitec• GreenlaneBiogas• MalmbergWater• NeoZeo• PentairHaffman• PuracPuregas• ScandinavianBiogas• Sysadvance
Addi6onalfunding:WasteManagementSweden(AvfallSverige)DGC,DanishGasTechnologyCentreStockholmGasTheSwedishWater&WastewaterAssocia&on(SvensktVamen)SVGW(SwissGasIndustry)
Projectpartner:
Report
Wanttoknowmore?Thereport”Biogasupgrading–technicalreview”andmanymorereportsonbiogascanbefoundat
hmp://www.energiforsk.se/rapportsok/