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 kerstin.hoyer@energiforsk.se

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/