Concepts for Large Scale Hydrogen Production - NTNU Open

Concepts for Large Scale HydrogenProduction

Daniel JakobsenVegar Åtland

Master of Science in Mechanical Engineering

Supervisor: Petter Nekså, EPTCo-supervisor: David Berstad, SINTEF Energy Research

Øivind Wilhelmsen, SINTEF Energy Research

Department of Energy and Process Engineering

Submission date: June 2016

Norwegian University of Science and Technology

i

Abstract

The objective of this thesis is to perform a techno-economic analysis of large-scale, carbon-lean

hydrogenproduction inNorway, in order to evaluate variousproductionmethods andestimate a

breakevenpricelevel.Norwaypossessesvastenergyresourcesandtheexportofoilandgasisvitalto

thecountry’seconomy.Theresultsofthisthesisindicatethathydrogenrepresentsaviable,carbon-

leanopportunitytoutilizetheseresources,whichcanprovekeyinthefutureofNorwegianenergy

exports.

Thisthesisevaluatessixdifferentsystemsforhydrogenproduction;Steammethanereforming(SMR),

SMRusinghydrogenas fuel in the furnace (SMR+),autothermal reforming (ATR),partialoxidation

(POX),waterelectrolysisandasystemcombiningelectrolysisandATR.AspenHYSYSsimulationtoolis

usedtoanalysethementionedproductionsystems.ThesimulationsshowthatSMRandATRproduce

hydrogenwiththehighestenergyefficiencyof0.82.Althoughtheefficienciesaresimilar,producing

hydrogenwithATRreducestheemissionswith70%comparedwithSMR.SMRcaptures3047tonnes

ofCO2/dayandemits1198tonnes/day,whileproducing500tonnesofhydrogen/day.

Withahydrogenproduction rateof500 tonnes/day,SMRproves tobemostcost-efficient,witha

breakevenpriceof1.51€/kgH2.Inthismethod,CCSaccountsfor0.32€/kgH2ofthetotalprice.ATR

producehydrogenat1.59€/kgH2,althoughwithasmallercarbonfootprint.Anaturalgaspriceof0.17

€/Sm3andanelectricitypriceof20.03€/MWhisappliedintheanalysis1.Giventhesamefeedstock

prices,electrolysisprovestobethemostcost-efficientproductionsystematcapacitiesuptoaround

150tonnes/day.Whenproducing100tonnesofhydrogen/day,thebreakevenpriceofelectrolysisis

1.87€/kgH2whileSMRproducesthehydrogenat1.94€/kgH2.Basedonearlymarketpredictionsand

given assumeddevelopment in distribution technology, hydrogen produced from all systems fully

evaluatedinthisthesiscanbecost-competitiveinexportscenarios.

AcasestudyofhydrogenproductioncombiningATRandelectrolysisinMid-Norwayisperformedto

testtheviabilityofutilizingexcesswindpowertoreduceproductioncost.Theresultsindicatethat,

giventheboundaryconditionsinthisthesis,acombinedelectrolysisandreformingsystemutilizing

excesswindpowerisnotlikelytobecost-competitivewitheitherstationaryCREpoweredbythegrid

ortraditionalreforming.

1BasedontheinternalgaspriceofStatoilandNasdaqNorwegianEL-commodities,respectively

iii

SammendragMålet med denne avhandlingen er å gjennomføre en tekno-økonomisk analyse av storskala

hydrogenproduksjonmedredusertCO2-utlippiNorge,foråkartleggeulikeproduksjonsmetoderog

estimereetprisnivå.Norgeinneharenormeenergiressurserogeksportenavoljeoggassersentralfor

landets økonomi. Resultatene i denne avhandlingen indikerer at hydrogenmed reduserte utslipp

representererenlevedyktig,alternativutnyttelseavdisseressursene,noesomkanvisesegviktigfor

fremtidentilnorskenergieksport.

Avhandlingen undersøker seks ulike hydrogenproduksjonssystemer; Dampreformering (SMR),

dampreformering hvor hydrogen erstatter naturgass i forbrenningskammeret (SMR+), Delvis

forbrenning(POX),Autotermiskreformering(ATR),elektrolyse(EL)ogetkombinasjonssystemmed

ATR og EL. Karbonfangst og lagring (CCS) er forutsatt i alle produksjonsanleggene. De nevnte

systemeneer simulertmedprosessverktøyetAspenHYSYS,og simuleringeneviser at SMRogATR

produsererhydrogenmedhøyestenergieffektivitet,0.82.Tiltrossforlikvirkningsgrad,operererATR

med70%mindreCO2-utslippsammenlignetmedSMR.Produksjonav500tonnhydrogen/dagmed

SMRmedførerfangstav3047tonnCO2/dagogutslippav1198tonnCO2/dag.

Gitt en produksjonskapasitet på 500 tonn hydrogen/dag viser SMR seg å være det mest

kostnadseffektivealternativet,medennullpunktsprispå1.51€/kgH2.MeddennemetodenstårCCS

for0.32€/kgH2avdentotaleprisen.ATRerberegnettil1.59€/kgH2,dogmedetbetydeligmindre

karbonfotavtrykk.Ennaturgassprispå0.17€/Sm3ogenelektrisitetsprispå20.03€/MWherbenyttet

ianalysen2.Gittdesammeråvarekostnadene,fremstårELsomdetmestkostnadseffektivealternativet

foranleggopptilrundt150tonnhydrogen/dag.Gittenproduksjonskapasitetpå100tonnhydrogen

omdagen,enderELogSMRmedennullpunktsprispåhenholdsvis1.87€/kgH2og1.94€/kgH2.Basert

påtilgjengeligemarkedsanalyseroggittantattteknologiutvikling,kanhydrogenprodusertfraallede

evaluertesystemeneidenneavhandlingenværekonkurransedyktigeieksportscenarioer.

EtstudieavkombinasjonsanleggetmedATRogELblegjennomførtiMidt-Norge,foråtestehvordan

utnyttelsen av overskuddsstrøm fra vindkraft kan redusere den totale produksjonskostnaden.

Resultateneviseratutnyttelsenavoverskuddsstrømsannsynligvisikkevilgibedrelønnsomhetenn

stasjonærproduksjon fraentennetteller tradisjonell reformering,gittgrensebetingelsene idenne

avhandlingen.

2BasertpåhenholdsvisStatoilsinternegassprisogNasdaqsstrøm-objekterENOYR17-19.

v

Preface

The present thesis was carried out at the Department of Energy and Process Engineering at the

NorwegianUniversityofScienceandTechnology(NTNU)fromJanuarytoJune2016.Oursupervisors

wereProfessor IIPetterNekså (NTNUandSINTEFEnergyResearch),DavidBerstad (SINTEFEnergy

Research)andØivindWilhelmsen(SINTEFEnergyResearch).

vii

Acknowledgements

Thisthesishasbeenrealizedwithhelpfromseveralknowledgeablepeople,bothinternallyatNTNU

andexternally.WewouldespeciallyliketothankoursupervisorsDavidBerstad,ØivindWilhelmsen

andProfessorPetterNekså.Wearegratefulforthetimetheyspentandfortheirinsightsandvaluable

contributionsthroughouttheprojectperiod.

WewouldalsoliketothankProfessorMagnusKorpåsforhisassistancewithinrenewablepowersystemsandenergystorage.

ix

TableofContentsAbstract..........................................................................................................................................i

Sammendrag.................................................................................................................................iii

Preface...........................................................................................................................................v

Acknowledgements......................................................................................................................vii

ListofFigures..............................................................................................................................xiii

ListofTables................................................................................................................................xvi

Listofabbreviations:....................................................................................................................xix

1 Introduction:...........................................................................................................................1

1.1 ScopeoftheThesis:................................................................................................................2

2 ConceptsforLarge-ScaleHydrogenProductionfromNaturalGas...........................................3

2.1 NaturalgasPre-treatment.....................................................................................................3

2.2 ReformingProcesses...............................................................................................................3

2.2.1 Pre-Reformer:.................................................................................................................4

2.2.2 SteamMethaneReforming(SMR)..................................................................................5

2.2.3 PartialOxidation(POX)...................................................................................................6

2.2.4 AutothermalReforming(ATR)........................................................................................7

2.2.5 Otherreformingprocesses.............................................................................................8

2.3 WaterGasShift(WGS)...........................................................................................................8

2.4 ConceptsforCO2Separation..................................................................................................9

2.4.1 PressureSwingAdsorption(PSA)...................................................................................9

2.4.2 Absorption......................................................................................................................9

2.4.3 MembraneSeparation.................................................................................................10

2.4.4 CryogenicSeparation....................................................................................................10

2.5 HydrogenPurificationProcesses..........................................................................................10

2.5.1 PressureSwingAdsorption(PSA):................................................................................10

2.5.2 MembraneSeparation.................................................................................................11

3 NorwegianHydrogenMarkets,andthePotentialforLarge-scaleProduction........................13

3.1 TransportationSector...........................................................................................................13

3.2 IndustrySector......................................................................................................................14

3.3 IsThereaPotentialforCentralizedHydrogenProductioninNorway?................................14

3.4 Whattodowith500TonnesofHydrogen?..........................................................................15

x

4 TechnicalAnalysisofLarge-scaleHydrogenProduction.........................................................16

4.1 Introduction:.........................................................................................................................16

4.2 CasePresentations...............................................................................................................16

4.2.1 System1:Streammethanereforming–SMR..............................................................16

4.2.2 System2:SteamMethaneReformingwithReducedCO2Emissions–SMR+..............17

4.2.3 System3:PartialOxidation–POX................................................................................18

4.2.4 System4:AutothermalReforming–ATR.....................................................................18

4.2.5 System5:Electrolysis–EL............................................................................................18

4.2.6 System6:CombinedReformingandElectrolysis–CRE...............................................19

4.3 MethodologyandSimulationofLarge-scaleHydrogenProduction.....................................19

4.3.1 GeneralDesignBasisandSimulationMethodology.....................................................20

4.3.2 SteamMethaneReforming(SMR)................................................................................21

4.3.3 SteamMethaneReforming,Improved(SMR+)............................................................24

4.3.4 PartialOxidation(POX).................................................................................................26

4.3.5 AutothermalReforming(ATR)......................................................................................28

4.3.6 ElectrolysisofWater(EL)..............................................................................................31

4.3.7 CombinedReformingandElectrolysis(CRE)................................................................31

4.4 TechnicalResultsandDiscussion..........................................................................................33

4.4.1 EnergyEfficiency..........................................................................................................34

4.4.2 CO2emissions...............................................................................................................34

4.4.3 SMRResultsandDiscussion.........................................................................................35

4.4.4 SMR+ResultsandDiscussion.......................................................................................40

4.4.5 POXResultsandDiscussion..........................................................................................43

4.4.6 ATRResultsandDiscussion..........................................................................................46

4.4.7 CREResultsandDiscussion..........................................................................................49

5 FinancialAnalysisofLarge-scaleHydrogenProduction.........................................................53

5.1 FinancialRisk........................................................................................................................53

5.1.1 DiscountRate...............................................................................................................53

5.2 WhatIsthePriceTargetofCarbon-leanHydrogenProducedinNorway?...........................54

5.3 CostAnalysis.........................................................................................................................55

5.3.1 CostBreakdownSMR...................................................................................................57

5.3.2 CostBreakdownSMR+.................................................................................................58

5.3.3 CostBreakdownATR....................................................................................................59

5.3.4 CostBreakdownCRE....................................................................................................60

xi

5.3.5 EnergyInputCosts........................................................................................................61

5.3.6 ProductionFacilityCosts..............................................................................................61

5.3.7 CarbonCaptureandStorageCosts...............................................................................62

5.4 BreakevenPriceofHydrogen...............................................................................................62

5.5 CostComparisonwithH2AReportbyNationalRenewableEnergyLaboratory...................64

5.6 EnvironmentalImpact..........................................................................................................67

5.6.1 CO₂Emissions...............................................................................................................67

5.7 SensitivityAnalysis................................................................................................................69

5.7.1 OptimisticCaseandConservativeCaseScenarios.......................................................69

5.7.2 ChangesinenergyinputCost.......................................................................................70

5.7.3 CarbonTax....................................................................................................................73

5.7.4 SystemDesignVariations.............................................................................................74

5.7.5 FinancialMarketChanges............................................................................................76

5.8 Techno-EconomicEvaluationofLarge-scaleHydrogenProductioninNorway....................77

6 ACaseStudyApproachtoHydrogenProductionCombiningGasReformingandElectrolysis.80

6.1.1 TjeldbergoddenIndustrialComplex.............................................................................81

6.1.2 FosenandSnillfjordenWindFarm...............................................................................81

6.2 StationaryProduction...........................................................................................................81

6.2.1 StationaryCase1,NaturalGas-basedCo-productionofHydrogen:............................81

6.2.2 StationaryCase2,Wind-basedCo-productionofHydrogen:.......................................83

6.3 FluctuatingProduction:........................................................................................................84

6.3.1 FluctuatingCase1:PartlyFlexibleElectrolysis.............................................................84

6.3.2 FluctuationCase2:FlexibleElectrolysis.......................................................................85

6.4 IsCombinedReformingandElectrolysisaCompetitiveSolution?........................................86

7 Conclusion............................................................................................................................89

8 ProposalsforFurtherWork...................................................................................................91

8.1.1 Proposalsforfurtherresearchwithinthehydrogenproductionprocesses:...............91

8.1.2 Proposalsforresearchwithintheexportvaluechain:.................................................92

References...................................................................................................................................93

Appendices..................................................................................................................................97

A. FinancialAnalysis–elaboration............................................................................................98

B. TechnicalAnalysis...............................................................................................................103

xii

C. WindData..........................................................................................................................120

xiii

ListofFigures

Figure1-Mainstepsofhydrogenproductionfromnaturalgas.Naturalgasreformingwillbethemain

focusofthisthesis..........................................................................................................................3

Figure2-GasHeatedReformer.IllustrationbyThyssenKruppIndustrialSolutions[7]........................4

Figure3-SteamMethaneReformerReactor.IllustrationbyTyssenKruppIndustrialSolutions[7].....5

Figure4-AutothermalReformingReactor.IllustrationbyTyssenKruppIndustrialSolutions[7].........7

Figure5-SMRflowchart......................................................................................................................17

Figure6-SMR+flowchart....................................................................................................................17

Figure7-POXflowchart.......................................................................................................................18

Figure8-ATRflowchart.......................................................................................................................18

Figure9-Electrolysisflowchart...........................................................................................................19

Figure10-CREflowchart.....................................................................................................................19

Figure11-CO2overview.Thisblockdiagramshowstheamountofcarbondioxidecapturedfromthe

syngasstream.TheemittedCO2ofATRandCREiscalculatedfromthecarboncompositionofthe

PSAtailgas...................................................................................................................................35

Figure 12 - How the Plant Energy Efficiency and the reforming Conversion Rate is changing with

differenttemperaturesinSMR....................................................................................................38

Figure13-HowtheplantenergyefficiencyandtheconversionrateischangingwithpressureinSMR

......................................................................................................................................................39

Figure14-GraphshowinghowtheplantenergyefficiencyandCO2emissionsareaffectedbychanges

inreformertemperatureinSMR+................................................................................................42


intheoxygen-to-fuelratioinPOX................................................................................................45


inO/FrationinATR......................................................................................................................49

Figure17-GraphsshowinghowtheplantenergyefficiencyandCO2emissionsareaffectedbychanges

intheO/Fratio.............................................................................................................................51

Figure18-CAPEXBreakdownoftheSMRsystem.Thethreelightgreyvaluesarerelatedtohydrogen

production.ThethreedarkgreyvaluesarerelatedtoCCS.........................................................57

Figure19-OPEXbreakdownoftheSMRsystem.Thecostofnaturalgasdominatewithcloseto65%

oftheexpenditures......................................................................................................................57

Figure20-CAPEXBreakdownoftheSMR+system.NoticethesignificantincreaseinH2production

plantinvestmentcost.Thisisduetotheincreasednaturalgasprocessinputandhencealarger

reactor..........................................................................................................................................58

xiv

Figure 21 -OPEX Breakdown of the SMR+ system. The natural gas cost dominate as in SMR. The

generalcostlevelhasincreasedevenly.......................................................................................58

Figure 22 - CAPEX Breakdown of the ATR system. Differs from SMRmainly on the less expensive

reformerandtheinclusionofanairseparationunit...................................................................59

Figure23-OPEXBreakdownoftheATRsystem.Thenaturalgasdominateamongtheexpenditures,

buthere,costofelectricityimpactstoalargerextent................................................................59

Figure24-CAPEXbreakdownofthecombinedreformingandelectrolysissystem............................60

Figure25 -OPEXbreakdownof thecombinedreformingandelectrolysissystem.Here, thecostof

naturalgasandelectricityareclosetoequal...............................................................................60

Figure26-Blockdiagramshowingthebreakevenpriceofcarbon-leanhydrogen.Includesallauxiliary

components, including CCS. 500 tonnes of H2 daily, delivered at 20 bar. The blue and green

colours indicate the share of which OPEX and CAPEX contribute throughout the lifetime,

respectively.10%discountrateand25yearslifetime.................................................................63

Figure 27 - Block diagram showing the breakeven price of carbon-lean hydrogen, highlighting the

additionalcostCCSrepresentsinthedifferentsystems.KeepinmindtheamountofCO2captures

isdifferentforeachsystem..........................................................................................................64

Figure28-ResultsoftheH2Aanalysisofhydrogenproductionmethods.TheFutureestimationsare

based on 2025 projections [31]. Keep in mind that the values are displayed in 2005$. The

conversionfactorto2016$is1.225[40]......................................................................................65

Figure29-RangeofBreakevenpriceofhydrogenproduction...........................................................70

Figure30-Breakevenpriceofhydrogenwithchangesintheelectricityprice...................................71

Figure31-Breakevenpriceofhydrogenvs.naturalgasprice............................................................72

Figure32-Breakevenpriceofproducedhydrogen,givennaturalgasandelectricitypricesfluctuateat

thesamerate...............................................................................................................................72

Figure33-Breakevenpriceofhydrogenvs.costofCO2emissions.SMRwithoutCCSisaddedinorder

to see how high the carbon price must be in order for carbon-lean hydrogen to be cost-

competitive..................................................................................................................................74

Figure34-Breakevenpriceofhydrogenvs.productioncapacity.Mindthechangeonthex-axisfrom

100to500tonnes/day.................................................................................................................75

Figure35-Breakevenpriceofhydrogenvs.energyefficiencyoftheelectrolysisplant.....................76

Figure36 -BreakevenpriceofCarbon-leanHydrogen.Calm financialmarket.7%discount rate.30

yearslifetime................................................................................................................................76

Figure37-BreakevenpriceofCarbon-leanHydrogen.Strictfinancialmarket.15%discountrate.20

yearslifetime................................................................................................................................76

xv

Figure38-ThemapshowsthelocationoftheFosen/Snillfjordenwindfarms.Thereddotmarksthe

locationofTjeldbergodden IndustrialComplexandtheHeidrungas-receiving terminal.Photo:

Statkraft[45]................................................................................................................................80

Figure39 -Graphshowinghowtheelectricityprice required to reach the referencepriceand the

powersuppliedbythewindfarmareaffectedbychangesinthedesignedelectrolysercapacity.

......................................................................................................................................................87

xvi

ListofTables

Table1-Listofviableairseparationtechnologies[11].........................................................................7

Table2-SummaryofperformancefordifferentoptionsforhydrogenandCO2separationfromsyngas

[8].................................................................................................................................................12

Table3-SMRdesignparameters.........................................................................................................22

Table4-SMR+designparameters.......................................................................................................25

Table5-POXdesignparameters.........................................................................................................26

Table6-ATRdesignparameters..........................................................................................................28

Table7-Technicalspecificationsofelectrolysis[29]..........................................................................31

Table8-CREdesignparameters..........................................................................................................32

Table 9 - Overview of the simulation results, comparing the individual production systems. All

efficienciesareLHV-based...........................................................................................................33

Table10-SMRSimulationOverview.Thistableshowsthestreampropertiesandcompositionthrough

theproductionprocess.ItishelpfultolookatFigure5togettheoverviewwhilestudyingthis

table.............................................................................................................................................36

Table11-PresentationofhowSMRparameterschangebychangingthereformingtemperature.The

chosendesignvaluesarehighlighted...........................................................................................36

Table12-HowSMRparameterschangebychangingtheS/Cratiointhereformer.Thechosendesign

valuesarehighlighted..................................................................................................................38

Table13-SMR+SimulationOverview.................................................................................................40

Table14-PresentationofhowSMR+parameterschangebychangingthereformingtemperature.The

designvaluesarehighlighted.......................................................................................................41

Table15-HowSMR+parameterschangebychangingtheS/Cratiointhereformer.Thedesignvalues

arehighlighted.............................................................................................................................42

Table16-POXSimulationOverview....................................................................................................43

Table17-POXparameterssensitivitytochangesinO/Fratio............................................................44

Table18-ATRSimulationOverview....................................................................................................46

Table19-ATRparameterssensitivitytochangesinO/Fratio............................................................47

Table20-ATRparameterssensitivitytochangesinS/Cratio.............................................................48

Table21-CREsystemoverview...........................................................................................................49

Table22-CREparameterssensitivitytovariationsintheO/Fratio,givenoptimalS/Cratio.............50

Table23-CREparameterssensitivitytovariationsinS/Cratio..........................................................51

Table24-CAPEXoverviewofthehydrogenproductionsystems.Allsystemsaredesignedwithadaily

productioncapacityof500tonnesofH2,deliveredat20bar.....................................................55

xvii

Table25-OPEXoverviewofthehydrogenproductionsystems.Allsystemsaredesignedwithadaily

productioncapacityof500tonnesofH2,deliveredat20bar.....................................................56

Table 26 - Cost comparison of this thesis with the results of H2A. Here, the breakeven price of

hydrogenfromH2Aisconvertedfrom2005$to2016€,basedonthestandardcurrencyexchange

rateusedaswellasaUSinflationcalculator[40],[31]...............................................................66

Table27-AnnuallyCO₂CapturedandAvoided...................................................................................68

Table28-CO₂emittedperkWhelectricityproduced.........................................................................68

Table29-ThistableshowshowthebreakevenpriceofATRwilldifferwhenvaryingtheCCScapacity.

ATR2isacasewithsimilarcarboncaptureasSMR.ATR3hassimilaremissionlevelasSMR...69

Table30-Keyfiguresfromthetechnicalandfinancialanalyses.........................................................78

Table31-Stationarycase1results.Thefullnaturalgascapacityisused,withelectrolyserssupplying

oxygenaswellasproducingadditionalhydrogen.......................................................................82

Table32 - Stationary case1:Benchmarkbreakevenpriceofhydrogenproduction, given the same

feedstockdemands......................................................................................................................82

Table33-Stationarycase2results.Thesystemisdesignedbasedontheannualaveragepowersupply

fromthewindfarm.TheparallelATRsystemisdesignedbasedontheproducedoxygen.........83

Table 34 - Stationary case 2: Benchmark breakeven price of hydrogen production, given same

feedstockdemands......................................................................................................................84

Table 35 - Fluctuating case 1: Partly flexible electrolysis with an electrolysis capacity of 600MW.

Highlightsfromthesimulationispresentedhere.ShowingtheBreakevenpriceofthehydrogen

producedaswellastherequiredelectricitypricetoequalthereferencepriceofstationarycase

2....................................................................................................................................................85

Table 36 - Fluctuating case 2: Flexible electrolysis,with capacity of 1000MW.Highlights from the

simulationispresentedhere.ShowingtheBreakevenpriceofthehydrogenproducedaswellas

therequiredelectricitypricetoequalthereferencepriceofstationarycase2..........................86

Table37-Currencytable-AveragesFebruary-March2016................................................................98

Table38-Definitionoftheoptimistic,baseandconservativecaresimulationsforSMR...................98

Table39-Definitionoftheoptimistic,baseandconservativecaresimulationsforATR....................99

Table40-Definitionoftheoptimistic,baseandconservativecaresimulationsforElectrolysis......100

Table41-Listofinputsusedforthecost-estimationsandnetpresentvaluecalculationsinEXCEL100

Table42-TestofEOS,withagivennaturalgasinputtotheSMRprocess.......................................103

Table43-Electrolysisplantpowerconsumption..............................................................................104

Table44-HeatdemandandheatavailableinSMR...........................................................................105

Table45-HeatdemandandsourcesinSMR+...................................................................................105

xviii

Table46-HeatdemandandheatavailableinPOX...........................................................................106

Table47-HeatdemandandheatavailableinATR............................................................................106

Table48-HeatdemandandheatavailableinCRE............................................................................107

Table49-NaturalGascompositionandproperties.MeanValuesfromHeidrungasfield[51]........107

Table50-Airdesignparameters.......................................................................................................108

Table51-Waterdesignparameters..................................................................................................108

Table52-Oxygendesignparameters................................................................................................108

Table53-HeatersandCoolersmodellingparameters......................................................................108

Table54-Compressorsmodellingparameters.................................................................................108

Table55-Expandersmodellingparameters......................................................................................109

Table56-Pumpsmodellingparameters...........................................................................................109

Table57-GHRmodellingparameters...............................................................................................109

Table58-SMRmodellingparameters...............................................................................................110

Table59-Furnacemodellingparameters.........................................................................................111

Table60-POXmodellingparameters................................................................................................111

Table61-ATRmodellingparameters................................................................................................112

Table62-WGSmodellingparameters...............................................................................................112

Table63-Separatormodellingparameters.......................................................................................113

Table64-CO2Absorptionmodellingparameters..............................................................................113

Table65-PSAmodellingparameters................................................................................................114

Table66-WinddatatextfileusedintheMatlabscript.Onlythefirst30of8058entriesisshowedin

thetable.Thewinddataiscapturedoverayearat3differentlocationsinMid-Norway........120

xix

ListofAbbreviations:

ATR–AutothermalReforming

CAPEX–Capitalexpenditures

CCGT-CombinedCycleGasTurbines

CCS–CarbonCaptureandStorage

CRE–CombinedReformingandElectrolysis

EJ-Exajoule

EL–Electrolysis

FCV–FuelCellVehicles

GHR–GasHeatedReformer

HHV–HigherHeatingValue

HTS–HighTemperatureShift

IEA–InternationalEnergyAgency

LHV–LowerHeatingValue

LNG–LiquidNaturalGas

LTS–LowTemperatureShift

MDEA-MethylDiethanolamine

MEA–Monoethanolamine

NG–NaturalGas

O/F–Oxygen-to-Fuel

OPEX–OperationalExpenditures

PEMFC–ProtonExchangeMembraneFuelCell

POX–PartialOxidation

PR–Peng-Robinson

PSA–PressureswingAdsorption

S/C–Steam-to-Carbon

SMR–SteamMethaneReforming

WGS–Water-gasShift

1

1 Introduction:

The global energy system is experiencing a change of scenery. Unstable energy markets and an

increasingfocusonclimatechangeandsustainabledevelopmentisforcingbusinessestopursuenew

solutionsinordertoensurefutureeconomicgrowth.Thishasledtotheinterestinusinghydrogenas

anenergycarrierintransportationandindustrialapplications.

Asanenergycarrier,hydrogenisaccessibleandholdsahighgravimetricenergydensity.Abundantin

hydrocarbons, hydrogen can play an important role in the shift towards low-emission fossil value

chains.Bycombininghydrogenproductionbynaturalgasreformingwithcarboncaptureandstorage,

theoverallCO2emissionsaresignificantlyreduced.Inaddition,theflexibilityofhydrogenasanenergy

storage medium makes it applicable as a stabilizer in the renewable energy mix. The recent

development in hydrogen fuel cells is also raising the expectations for a hydrogen powered

transportationsector.

Hydrogenvaluechainsexisttoalargeextentintheindustrytoday.Theglobalhydrogenconsumption

was approximately 50 million tonnes (7.2 EJ) in 2013, where refineries, ammonia and methanol

productionandmetalprocessingweremainconsumers[1].Naturalgasreformingproduced48%of

this hydrogen, but without carbon capture and storage (CCS) [1]. The total emissions from the

production reached 500million tonnes of CO2, hence alternative productionmethodswith lower

emissionswillbenecessaryinfuturevaluechains.

With the potential of being a sustainable solution to both the fossil industry and transportation,

hydrogen inarguably has great benefits. This also benefits Norway.With one of Europe’s largest

natural gas reserves, capacious and available reservoirs for carbon storage and some of the best

accessiblewindconditions in theworld,Norwayhas theopportunity tobe in the forefrontof the

development of future hydrogen value chains. The export of oil and gas is vital to the country’s

economyandnewcarbon-leanmethodsofutilizingtheseresourcescouldprovekeyinthefutureof

Norwegianexports.

Theaimofthisthesisistoevaluatethetechnicalandeconomicpotentialoflarge-scaleproductionof

carbon-leanhydrogeninNorway.First isa literaturesurvey,explainingthemainstepsinhydrogen

productionfromnaturalgas,followedbyfuturehydrogenmarketconsiderations,bothofdomestic

andinternationaldemand.Further isadetailedtechno-economicanalysisofcarbon-leanhydrogen

2

production, evaluating strengths and weaknesses of the individual processes in the context of

Norwegianhydrogenproductionforexport.Thelastpartconsistsofdifferentcasestudies,evaluating

specificprocessdesignscombiningtheutilizationofstrandednaturalgasandexcesswindpowerin

Mid-Norway.

Whatdifferentiatesthisthesisfromotherstudiesonlarge-scalehydrogenproductionismainlytwo

factors:ThepresenceofNorwegianenergyresourcesandCCSopportunities,aswellasa focuson

reducedCO2emissions.ThebreakevenpriceofhydrogenproducedinNorway,withthecurrentcost

ofelectricityandnaturalgasmayproveexceptionalcomparedwithcountrieslikeGermany,U.K.or

Japan.Theopportunitieshydrogenrepresentsinthefutureeconomyprovidesthemotivationfora

more extensive study of the techno-economic conditions for Norwegian, large-scale hydrogen

production.

1.1 ScopeoftheThesis:

In order to conduct an analysis to this extent, a defined scope is necessary. Listed are themain

boundaryconditionsandtechnicalassumptionsinthethesis.

1. Desulfurized natural gas and electricity are the only energy inputs used in this thesis.

Hydrogencanbeproducedfromalargeselectionoffeedstocklikecoalorbiogas,butthatis

not included. Biogas may be a viable alternative in the future, but coal is irrelevant in a

Norwegianhydrogenproductionchain.

2. Onlymature, commercially available technologies for large-scale hydrogen production are

considered.

3. Carboncaptureisaprerequisiteinthereformingprocessesandonlypre-combustionCCSis

evaluated. Carbon capture from flue gaswith lowpartial pressures is not included in this

thesis, due to lackof commercial availability. Carbon captureathighpartial pressures are

currentlyinoperationatboththeSleipneroilfieldandatMelkøya[2][3].

4. Carbontransportandstoragetechnologyisoutofscope.ThecostoftheentireCCSchainis

included,butnotechnicalanalysisisdoneoneithertransportorstoragealternatives.

5. The scale of the hydrogen production evaluated in this report is motivated by export

scenarios.

3

2 ConceptsforLarge-ScaleHydrogenProductionfromNaturalGas

This chapterwillprovideawalk-throughof large-scalehydrogenproduction fromnaturalgas.The

mainstepsofnaturalgasreformingwillbediscussedaswellastheseparatetechnologiesavailableto

fulfilthesesteps.Figure1showsthefivestepsthisthesishasdefinedasthemaingroupsofprocesses

inahydrogenproductionfacility:naturalgaspre-treatment,naturalgasreforming,watergasshift,

carboncaptureandhydrogenpurification.Of these five,natural gas reforming is the focusof this

thesis. As the scope of the thesis assumes desulphurized natural gas, step number one is less

important.

Figure1-Mainstepsofhydrogenproductionfromnaturalgas.Naturalgasreformingwillbethemainfocusofthisthesis

2.1 NaturalgasPre-treatment

For natural gas, the only pre-treatment required is desulphurization [4]. Natural gas reforming is

usuallyacatalyticoperation,andthecatalystsarepoisonedbyevensmallamountsofsulphur.Catalyst

poisoning is in this casewhensulphur isadsorbedonto thecatalyst surface reducing thecatalytic

activitysignificantly[5].Thisresultsinareductionofthetotalplantefficiency.Sulphurpoisoningmay

be permanent and pre-treatment through desulphurization is therefore crucial for successful

productionofhydrogenfromnaturalgas[5].Whenpre-treatingNG,thefeedisfirstsentthrougha

flash drum, removing all the liquids. The organic sulphur in the NG is then blown with recycled

hydrogenandhydrogenated,releasingthesulphurasH2S.TheH2Sisadsorbedinazincoxidebedand

reactstoformzincsulphide,whichisremovedasasolidwaste[6].Thedesulphurisationoperating

temperatureisbetween260-430°Candthepressureisupto50bar.Asthescopeofthethesisassumes

desulphurizednaturalgasfeed,thisstepisnotdiscussedanyfurther.

2.2 ReformingProcesses

Althoughhydrogenisinanearlystageasafuelwithinthetransportationsector,ithasbeenamajor

commodityinindustryfordecades.Asmentionedintheintroduction,theglobalhydrogendemand

was7.2exajoules(EJ)in2014,equivalentto50milliontonnes[1].48%ofthishydrogenisproduced

from the reforming of natural gas. This section will explain the main reforming principles and

technologiesavailable.

Natural GasPre-Treatment

Natural GasReforming WaterGasShift CarbonCapture Hydrogen

Purification

4

2.2.1 Pre-Reformer:

Theprincipleofthepre-reformeristoconvertheavierhydrocarbonstomethanepriortothemain

reformingreactor.Thepre-reformingreactorusuallycontainsanickelcatalystbedandisbasicallya

lowtemperatureadiabaticsteamreformingunit.Thetemperatureisnormallyintherangefrom350

–550°C[4].Thereareseveralbenefitstopre-reforming,butmostimportantistheenablingofprocess

optimization of methane reforming. This results in lower feed consumption and hence a smaller

reactorsize.

2.2.1.1 GasHeatedReformer

Oneexampleofasophisticatedpre-reformeristhegasheatedreformer(GHR),alsoreferredtoasa

convectivereformer.Whatdifferentiatesitfromthetraditionalsteammethanereforming(SMR)is

the temperature range and themethod of heat transfer.Where the SMR reactors are heated by

externalcombustionofnaturalgasinasystemofreactortubesandburners,theGHRworksasaheat

exchanger,absorbingenergybyconvectiveheattransferwithanothergas[7].Figure2showsthebasic

principlesoftheGHR.Inanintegratedsystem,theGHRcanbeusedasbothapre-reformerandaheat

exchangercoolingthesyngaspriortothewatergasshiftreactors.

Figure2-GasHeatedReformer.IllustrationbyThyssenKruppIndustrialSolutions[7]

5

2.2.2 SteamMethaneReforming(SMR)

Awidelyusedmethodtoproducehydrogenfromnaturalgas(NG)isbytheuseofsteammethane

reforming(SMR)[4].ThereactionisendothermicandconvertssteamandmethaneintoH2andCOas

showninequation2.1.

CH# + H%O ⇌ CO + 3H% (2.1)

Theactivationenergyneededis206kJ/mol.Thereactionisacatalyticreactionsupportedbynickel-

based catalysts. Nickel-based catalysts are cost efficient and have sufficient activity. Whenmore

activityisneeded,amorenoblecatalystcanbeused.Nobelcatalystsprovideshigheractivitiesand

fasterreactionsbutareveryexpensive[4].Thereactorconsistsofseveralreactortubesfilledwith

reformingcatalystsandkeptinafurnacethatprovidesthenecessaryheatforthereactiontohappen.

ThedesignisillustratedinFigure3.

Figure3-SteamMethaneReformerReactor.IllustrationbyTyssenKruppIndustrialSolutions[7].

6

Thereactionisnormallycarriedoutatpressuresabove20bar,steam-to-carbon(S/C)ratioof3-43on

amolarbasisandtemperaturesbetween500-900°C[8].AhigherS/Cratioispartiallytoreducethe

riskofcarbondepositiononthecatalystsurface[4].Highconversionisthermodynamicallyfavoured

bylowpressures,highS/Cratioandhightemperatures.Fromanenergyefficiencyandeconomicpoint

of view, lowS/C ratio is preferred andmodern SMR-plants havebeendesign towithstandhigher

temperatures.Theuppertemperaturelimitisduetomateriallimitations.SMRusuallyoperatesatan

energyefficiencyupto80-85%andgenerallyproducesmorehydrogenpercarbonthanbothPOXand

ATR[9].H2/COratioistypicallybetween3.5and5.5inthereformedproduct[10].

2.2.3 PartialOxidation(POX)

Afundamentallydifferentmethodofproducinghydrogen fromnaturalgas isby theuseofpartial

oxidation(POX).Thereactionisexothermic,incontrasttothehighlyendothermicSMRreaction.By

burningthenaturalgaswithalimitedoxygensupply,theproductsareH2andCO,asshowninequation

(2.2).Thismethodcanintheorybeappliedtoanyhydrocarbon,henceitisamethodforavarietyof

feedstock.

C)H* +m

2O% ⇌ mCO +

n

2H% (2.2)

Ascanbeseenbythereaction(eq.2.2),aPOXreactorhasahydrocarbonandanoxygeninput.Most

large-scalesystemsincludeanairseparationplantinordertosupplycleanoxygen.Thisdoesnotonly

reducethenecessarysizeofthereactor,butalsoincreasethepurityoftheoutput[4].Thecaseswhere

air-blown reactors are used, nitrogen is favourable in the product, as is the case for ammonia

production.TheenergyefficiencyofPOXisaround70-80%withthereactorsusuallyoperatingat

temperaturesbetween1150-1500°C[4].

2.2.3.1 Airseparationunits

Sincethisthesisisfocusingonfuelcell-gradehydrogenproduction,closetopureoxygenisneededin

thepartialoxidation.Manydifferentsystemsforairseparationisavailable,butiftheoxygenpurityis

expectedat>99.99%onlycryogenicairseparationisaviableoptioninalarge-scalefacility.Themost

availabletechnologiesusedforairseparationarelistedinTable1.

3InterviewwithSINTEFResearchScientistRahoulAnantharaman

7

Table1-Listofviableairseparationtechnologies[11].

Process Status Productionsize

(tonnes/day)

By-product

capability

PurityLimit

(vol.%)

Start-up

time

Adsorption: Semi-mature <136 Poor 95 Minutes

Cryogenic: Mature >18 Excellent 99+ Hours

Membrane: Semi-mature <18 Poor ~40 minutes

2.2.4 AutothermalReforming(ATR)

Autothermal reforming (ATR) is the combination of POX and SMR in one reactor. NG is partially

oxidisedinacombustionzone,whilesteamisinjectedinaSMRzone.Hence,boththePOXandthe

SMRreactionsareactivesimultaneously.Thisconceptalsoneedpureoxygeninputaswellasacatalyst

bedinthesteamreformingsectionofthereactor.Thecorebenefitsofthissystemisthattheheat

generatedbythePOXreactionisconsumedbytheendothermicSMRreaction.Thisenablesaclosed

system,insulatedfromexternalheatsupply.Inaddition,sincetheoxidationoccurswithinthereaction

chamber,fluegasisnotproduced,resultinginthepotentialofnolocalemissions.

Figure4-AutothermalReformingReactor.IllustrationbyTyssenKruppIndustrialSolutions[7]

8

TheATRreactorsusuallyoperateattemperaturesbetween900-1150°C,withpressurelevelsinthe

range1to80barexistingtoday[4].Figure4showstheprinciplesoftheATRreactor,withthedifferent

inputsandreactionzones.NospecificrangewasfoundforthetypicalenergyefficiencyofATR,butit

shouldoperatewithlowerenergyefficiencythanSMR[12].

2.2.5 Otherreformingprocesses

ThepaperbyMariVoldsund,KristinJordalandRahulAnantharaman,“HydrogenProductionwithCO2

Capture”isusedactivelywhenlookingatotherreformingprocesses[8].

2.2.5.1 MembraneReactors

Whenproducinghydrogeninmembranereactors,achemicalreactionliketheonesinSMR,POXor

ATR,mentioned in section 2.2.2 to 2.2.4, take place inside a reactor where either H2 or CO2 are

selectivelyremovedbyamembrane[8].Thisshiftstheequilibriumofthereactions,whichresultsin

higherconversion,and/orallowsreformingofhydrogenatmilderthermalconditions[8].H2-selective

reactorshaveahighereffecton the reaction conversion rate compared toCO2-selective reactors,

thereforefarmoreresearchisdoneontheH2-selectivereactors[8].Thesemembranereactorsare

currentlyinadevelopingphaseandarenotcommerciallyavailable.

2.2.5.2 Sorption-enhancedhydrogenproduction

Sorption-enhancedhydrogenproductionistouseadsorbentsinthereactortoselectivelyremoveone

ormoreoftheproductsreformed.Thiswill,similartomembranereactors,shifttheequilibriumofthe

reactions,resultinginhigherconversionand/orthepossibilitytoreformhydrogenatmilderthermal

conditions[8].Sorption-enhancedhydrogenproductionisinprinciplecombiningtraditionalhydrogen

production(SMR,POXandATR)withhydrogenpurification(PSA).Thistechnologyisalsocurrentlyin

adevelopingphaseandisnotcommerciallyavailable[8].

2.3 WaterGasShift(WGS)

Afterthereformingprocess,thesyngasundergoesawatergasshift,wheretheCOisreactedwith

water, over a catalyst, to produce additional hydrogen as well as CO2. The process is slightly

exothermicandiscontrolledbyequilibrium[4].Itfollowsthereactionequation2.3.

CO + H%O ⇌ CO% + H% (2.3)

9

The equilibrium constant is a function of temperature,meaning the reaction is favourable at low

temperatures.Ontheotherhand,thereactionratesdiminishatlowtemperatures.Becauseofthis

theprocessisusuallydoneintwosteps,ahightemperatureshift(HTS)andalowtemperatureshift

(LTS). In theHTS, themole fractionofCO is reduced from typically10-13% to2-3%,withan inlet

temperaturebetween350-550°C.IntheLTS,theCOconcentrationisfurtherreducedto0.2-0.4%at

temperatures of 190-250 [4]. The lower limit is set due to the water dew point of the gas.

CondensationcoulddamagethecatalystsintheWGSchamber[4].

2.4 ConceptsforCO2Separation

AftertheWGS,hydrogenandCO2areproducedandhavetobeseparatedandpurified.Conceptsfor

CO2separationarepresentedinthissection,whiledifferentconceptsforhydrogenpurificationare

presentedinSection2.5.

2.4.1 PressureSwingAdsorption(PSA)

AdsorptioncanbeusedtopurifyCO2formthesyngas.Thisisusuallydonebetweenthereformingand

thehydrogenpurification, and isdonewithCO2-selectiveadsorbents. Theprocess consistsof two

steps;first,wetCO2isremovedinCO2-selectiveadsorbentbeds.Second,CH4,CO,remainingCO2and

otherimpuritiesareremovedfromthehydrogen[8].Asmuchas90%oftheCO2canbecapturedwith

apurityof97%usingthistechnology.

2.4.2 Absorption

CO2absorptionisacommerciallymaturetechnologyandiscommonlyusedtoremoveCO2fromNG

[8]. The liquid solvent can be divided into two groups, chemical and physical solvents. Chemical

solventsreactwithCO2andrequireheattoactivatethereaction.Chemicalsolventsofferfastreaction

rateswhichresultsinsmallerplantsize.MDEA,MEA,TEAandpotassiumcarbonateareexamplesof

chemicalsolventsusedforCO2capture.PhysicalsolventsdonotreactbutdissolveCO2andrequire

lessheatthanchemicalsolvents.Rectisol®,Selexol™,andPurisol®areallexamplesoftechnologies

using physical absorption [8]. Chemical solvents have relatively high capacity at low pressure

comparedtophysicalsolventsandarethereforepreferredatlowCO2partialpressures.Thechemical

solventswillbegintosaturatewithincreasingCO2partialpressuresandphysicalsolventsaretherefore

preferred at high CO2 partial pressures. The CO2 recovery and purity will depend on the syngas

compositionandvarioussolventsmaybeoptimalforCO2separation.StudieshaveshownthatMDEA

cancaptureasmuchas95%oftheCO2withapurityofabove99%[8].

10

2.4.3 MembraneSeparation

TherearegreatchallengesseparatingCO2fromahydrogenrichgaswithmembraneduetohydrogen

molecules been significantly smaller than CO2. Current CO2-selective membranes are based on

solution-diffusionmechanismorfacilitatedtransportmechanism[8].Anexampleofsuchmembrane

ispolymericCO2-selectivemembranes.ThereexistotherCO2-selectivemembranesaswell suchas

mixedmatrixmembranesandporousinorganicmembranes.Thecurrent,commercial,CO2-selective

membraneshavelowselectivityandoperateatlowtemperatures[8].MoreresearchonCO2-selective

membranesisneededtodevelopanefficientmembranewithhighCO2selectivity.

2.4.4 CryogenicSeparation

Cryogenic,orlow-temperatureseparation,istheprocesswheregasiscooleddownandthedifference

inboilingpointisusedtoseparatethegascomponents.Thegasisseparatedusingaseparatorcolumn.

WhenseparatingCO2fromsyngas,thesyngasisfirstcompressedto90-115barandthencooleddown

andcondensedattemperaturesaround-55°C[8].CO2puritiesof99.7-99.9%witharecoveryof85-

90%canbeobtained[13].Anadvantagewithlow-temperatureseparationofCO2isthattheCO2ina

liquidstate,costefficientlycanbepressurizedandtransported.Cryogenicseparationcanalsobeused

toseparatehydrogen,butproduceshydrogenwithalowpurity.

2.5 HydrogenPurificationProcesses

Toliquefyhydrogenandtouseitinafuelcell,apurityofabove99%isrequired[8].Therearecurrently

onlytwohydrogenpurificationprocesseswiththeabilitytoproducehydrogenwithapurityofabove

99%andonlythesewillbecoveredinthissection.

2.5.1 PressureSwingAdsorption(PSA):

Over85%ofcurrentglobalhydrogenproductionunitsusePSAtechnologyforhydrogenpurification

andisthemostusedhydrogenpurificationtechnologytoday[4].WhenPSAisusedtopurifyhydrogen,

thesyngas issent throughanadsorptioncolumnathighpressures lettingthroughhydrogenwhile

adsorbingCO2andotherimpurities.Thepressureinsidethecolumnisthenlowerednearatmospheric

pressure desorbing impurities from the adsorption material. There are usually several columns

operating simultaneousmaking the hydrogen purification process semi-continuous. Columnswith

multiple adsorbents arenormally usedwhenpurifyinghydrogen. Typical adsorbents are silica gel,

alumina,activatedcarbonand zeolite [8].Operating temperature inPSAunits is typicallyambient

temperaturereceivingthefeedsyngasatapressurebetween20-60bar.Hydrogenispurifiedwitha

pressuredropbetween1-2bar.Theoff-gasexitstheunitwithpressuresbetween1-2bar.ThePSA

11

unitproduceshydrogenwithapurityupto99.9999%andwithahydrogenrecoverybetween60-95%

[8]. The hydrogen recovery decreases with an increase in the hydrogen purity demand. Where

methane,CO2andCOareeasilyadsorbed,oxygen,argonandnitrogenaremoredifficulttoadsorb

andmayreducethepurityoftheproducedhydrogen.

2.5.2 MembraneSeparation

Membranes are ideal for separation purposes as they are selective barriers and only let through

certaincomponents.Theessentialcharacteristicsformembranesarehighselectivity,highflux,low

cost,highmechanicalstability,highchemicalstability[8].Thetransportedfluidoverthemembraneis

drivenbythedifferenceinpressure.Thecurrentlymostmaturemembranesforhydrogenseparation

are polymeric membranes. These membranes have an operating temperature of 100°C and are

relativelyinexpensive,howeverpolymericmembraneshavelowhydrogenselectivityandhydrogen

flux.Polymericmembranescanthereforenotproducehydrogenwithhydrogenpurityof99%.There

aremanyhigh-temperaturemembranescurrentlyunderdevelopment.Suchasmetallicmembranes

(300-700°C),microporousceramicmembranes(200-600°C),porouscarbonmembranes(500-900°C)

anddenseceramicmembranes(600-900°C).Thesehigh-temperaturemembraneshavepossibilities

toofferhigherhydrogenfluxandselectivity.Themoststudiedmembraneforhydrogenpurificationis

metallicmembranes,mostoftenmadeofpalladium.Palladiummembraneshaveaninfiniteselectivity

andcanproducehydrogenwithapurityof99.999%.Thechallengeswiththepalladiummembranes

is themechanical strength and chemical stability. There arepalladiummembraneson themarket

today,buttheseareexpensiveandtodense(Lowflux).ReinertsenASarecurrentlydevelopingaless

densepalladiummembraneandstatesthatthismembranewillbecomecostefficient,deliverhigh

purity of hydrogen, havehighhydrogen recovery andhave a lifetimeof 10 years. Themembrane

ReinertsenASaredevelopingwillbesold inmodulesandcaneasilybescaledup fora large-scale

hydrogenproductionplant4.

4InterviewwithFrodeRoness,ReinertsenAS

12

Table2-SummaryofperformancefordifferentoptionsforhydrogenandCO2separationfromsyngas[8].

Unit Adsorption–

H2PSA

Adsorption–

CO2PSA

Absorption

–MDEA

Absorption

–Physical

Membrane

–Pd-based

Low

temperature

CO2capture

H2purity: mol% 98–99.9999+ Low(<91) Low(58) Low(83-86) 99-99.995 Low(81-83)

H2recovery: % 70-95 High High High n/a High

CO2purity: mol% Low(39-57) >97 99.9 95-99.7 Low 99.7-99.9

CO2

recovery:

% High >90 95 90-97 High 85-90

Syngas in

source:

SMR SMR Air-blown

ATR

Gasified

Coal

SMR GasifiedCoal

13

3 Norwegian Hydrogen Markets, and the Potential for Large-scale

Production

InNorway,CO2emissionsaredistributedevenlybetween transportation,oil andgas industry and

generalindustry.Producinghydrogenfromrenewableenergycanfacilitateacompletelycarbonfree

valuechain.Inaddition,environmentalfriendlysolutionsforreformingoffossilresourcescanprovide

costcompetitivealternativesinamarketpenetrationperiodforgreenhydrogen.Carboncaptureand

storage(CCS)enableslargereductionsintheoilandgassector.Thistechnologyisalreadyutilizedat

theSleipnerfieldandinHammerfest,accountingforanannualstorageof1.7milliontonnesofCO2

[14]. Producing hydrogen from natural gas enables a brilliant solution for the industry and

transportationsectortobenefitfromCCSaswell.TheNationaltransportplan,releasedinFebruary

2016highlightshydrogenasanimportantpartofalow-emissiontransportationsystem.Inaddition,

thecompanyGreenstatsignedaletterofintenttodeliveralarge-scalehydrogenproductionfacility

toTizirinTyssedal,redesigningthesmeltingovenfromacoal-basedtohydrogen-basedreduction.

This section will provide an overview of the developments in the hydrogen demand of the

transportationandindustrysectoraswellasdiscussingthepotentialforhydrogenexport.

3.1 TransportationSector

Thetransportationsectoraccountsforapproximately36%oftheannualCO2emissionsinNorway,

closeto17.2milliontonnesofCO2equivalents[15].Inthisthesis,thetransportationsectorincludes

allroadtraffic,aswellasdomesticairandmarinetraffic.Theneedforlow-emissionsolutionsacross

theentirerangeofutilitiesisurgent.Asanenergycarrier,hydrogencomplimentsthebatteriesinthe

more energy demanding and time consuming tasks, with longer range and short refuelling time.

Therefore,hydrogencanprovetobethefavourablecarbon-leansolutionforheavytransport,busses,

trains, ferries, and eventually airplanes. In a recent study done by SINTEF, different scenarios for

marketintroductionofhydrogenwithintheNorwegiantransportationsectorispresented[16].The

totalhydrogendemandinthetransportationsectorrangesfrom9500–61000tonnesperyearin

2030,mostlydependingonpoliciesand implementation inpublictransportationandfleetvehicles

likebussesandtaxis.

Amaster’sthesisperformedattheNorwegianSchoolofEconomicsevaluatesthepotentialofusing

hydrogenfuelinferriesalongtheNorwegiancoastline[17].Theprojectconcludesthathydrogenthat

withfurthercostcompression,hydrogencanpotentiallybeaneconomicallyviablefuelfortheferry

14

sector.Inordertoquantifythepotentialmarked,assumeallroutesexceeding10kilometresand30

minutesoftraveltimearefuelledbyhydrogen.Withafuelcellefficiencyof50%thetotalhydrogen

demandwouldbeapproximately15000tonnesannually,or41tonnesperday.

3.2 IndustrySector

Theglobal industrialhydrogendemandismainlywithinthechemicalandrefining industries[9]. In

Norway,theinformationregardingindustrialdemandforhydrogenislimited,butingeneral,themetal

andchemical industriesconsumesubstantialamountsofhydrogen invarioussiliconandammonia

productionprocesses.Asignificantgrowthindemandcanbeachievedifpolicyrequirementsenforce

aswitch tohydrogenconsumingprocesses inorder to reduceemissions.Asmentionedearlier,an

exampleofthisistheletterofintentsignedbyTizirandGreenstatinthefallof2015[18].Theproject

isafeasibilitystudyregardingthereplacementofcoalwithhydrogeninthereductionprocessinthe

ferrosiliconproductionfacility.Pre-studiesshowthathydrogenwillreduceproductioncostsaswellas

eliminating 23 000 tonnes of CO2 emissions annually from the smelting oven. The total hydrogen

demandofthisfacilityisexpectedtobe30tonnesperday,equalto11000tonnesannually.Compared

tothemarkedestimationsofhydrogeninthetransportationsectorthisfacilityaloneexceedsthelow-

casedemand.Thisshowswhyindustry,bothdomesticandinternational,ismostlikelytobethetarget

for centralized large-scale hydrogen production facilities. A feasibility study, similar to Tizir, is

conducted in Sweden by Vättenfall among others [19]. Here, the aim is to produce steel using

hydrogeninaprocesscalleddirectreduction.

3.3 IsThereaPotentialforCentralizedHydrogenProductioninNorway?

BasedonlyontheoverviewofthetransportationmarketinNorway,acentralizedproductionofmore

than 100 tonnes per day will be sufficient to supply more than 50% of even optimistic market

estimations.IfaScandinaviandistributionsystemisdeveloped,large-scalehydrogenproductionfor

industrialuseholdsamoreviablepotential.ThefeasibilitystudybyTizirwillbeacrucialnextstepfor

Norwegian,industrialhydrogen.Withthisinmind,alarge-scalehydrogenproductionfacilitywitha

capacity in the scaleofabove100 tonnesperdaywillbemore suited forexport ina carbon-lean

energytrade.

The internationaldemandforcarbon-leanhydrogen isestimatedto increaserapidly in thecoming

years[20].InWesternEurope,dominatedbyUKandGermany,thedemandforhydrogenisexpected

toreachmorethan9milliontonnesperdayin2030,withcarbon-leanhydrogenrepresenting15%in

aCO2policydrivenscenario[21].InJapan,concreteplansforhydrogenimportisonthetable.Already

15

in2012,Kawasakireleasedastrategyrelatedtoimportinghydrogenbasedonbrowncoalgasification

inAustralia,770tonnesperday[22].

Thisthesisusesaproductioncapacityof500tonnesofhydrogen/dayasalarge-scalebasescenario.

In an export scenario, this production size can supply around 10% of the estimated carbon-lean

hydrogenmarketinEuropein2030[20].

3.4 Whattodowith500TonnesofHydrogen?

Eventhoughhydrogenisafamiliarcompoundinindustry,thegeneralunderstandingofitasanenergy

carrierislimited.500tonnesofhydrogenhold19.7GWhofenergy.347daysofproductionaddsup

toatotalof6.8TWh,equalto0.2%oftheenergyconsumptionwithinroadtransportationinEU[23].

Incomparison,thetotalelectricityproductioninNorwayin2014was142.3TWh[24].Kawasakiare

developingliquidhydrogencarriersforlarge-scaleimport.Theassumedtankvolumeis160000m3,

abletohold11328tonnesofhydrogen5[25].Thisequals22daysofproductioninaplantwith500

tonnesperdaycapacity.

BasedonthespecificationofToyotaMirai,afuelcellelectricvehicle(FCEV)runsapproximately100

kmperkgofhydrogen[26].WithanaveragetraveldistanceofpersonalvehiclesinNorwayof12289

kmannually,500tonnesofhydrogenperdaycanpower1.4millioncars[27].Onahigherheating

valuebasis,1kgofhydrogenequalsapproximatelythesameamountofenergyas4litresofpetrol.

5Liquidhydrogendensityof70.8kg/m3

16

4 TechnicalAnalysisofLarge-scaleHydrogenProduction

4.1 Introduction:

This chapter will provide a technical analysis of the different systems converting natural gas to

hydrogen.Thesystemswillbedefinedandmodelled,andtheresultswillbepresentedinordertodo

acomparativeanalysis.Thescopeoftheprojectlimitsthehydrogenproductiontobebasedonnatural

gaswithCCS,aswellasitcomparestheresultstonon-fossilhydrogenproductionbyelectrolysisof

water.Thefollowinghydrogenproductionsystemswillbeevaluatedinthisthesis:

1. SteamMethaneReforming–SMR

2. SteamMethaneReforming,withreducedemissions–SMR+

3. PartialOxidation–POX

4. AutothermalReforming–ATR

5. Electrolysis–EL

6. CombinedAutothermalReformingandElectrolysis–CRE

Eachsystemisdesignedandoptimizedbasedonasteadystate,chemicalprocessmodel,simulatedin

thesoftwareAspenHYSYS.Thesystemsaredesignedforaproductioncapacityof500tonnesofpure,

carbon-leanhydrogeneveryday.

Throughoutthischapter,emphasiswillbeputonthefollowingparameters:EnergyefficiencyandCO2

emissions.Withincreasingpowerconsumption,theefficiencyofenergysystemsrequiresattention

althoughitisoftenrelatedtoincreasedinvestmentcosts.Withafixedhydrogenproductioncapacity,

ahighenergyefficiencycanbekeytoreduceoperationalexpenditures,aswellasCO2emissions.

4.2 CasePresentations

Thissectionpresentsthedifferentsystemsdefinedinthisthesis,inordertogetanoverviewofthe

individualdesigns.EachsystemwillbeexplainedindetailinSection4.3.

4.2.1 System1:Streammethanereforming–SMR

Systemnumberoneistraditionalsteammethanereforming(SMR),describedinSection2.2.2,with

carboncapturefromthesyngasstream.Theheatrequiredinthereactorisdeliveredbyafurnace,

17

burningtheprocesstailgasaswellasadditionalnaturalgasifneeded.Asystemflowchartispresented

inFigure5.

Figure5-SMRflowchart

4.2.2 System2:SteamMethaneReformingwithReducedCO2Emissions–SMR+

Becauseoftheexternalcombustion,CCSislimitedtoapproximately70%oftheCO2producedinSMR,

disregardingcarboncapturefromthefluegas.Therefore,anewSMRdesign,replacingthenaturalgas

feed in the furnacewithhydrogen, is defined inorder to reach close to90%carbon capture. The

systemisnamedSMR+andpresentedinFigure6.

Figure6-SMR+flowchart

18

4.2.3 System3:PartialOxidation–POX

The third systemanalysed in this thesis is partial oxidation (POX), described in Section2.2.3. POX

differsfromSMRbyutilizingtheexothermiccombustionofnaturalgaswithlimitedoxygensupply,

producinghydrogenandCO,insteadofwaterandCO2.Figure7showsthesystemlayout.

Figure7-POXflowchart

4.2.4 System4:AutothermalReforming–ATR

ATR, described in Section 2.2.4, utilize the heat produced from the exothermic POX to fuel the

endothermicSMR,resulting inanefficientsystemwith internalcombustion.Thisdesignallowsfor

extensiveCCS,without compromisingonefficientoperation. The flowchartofATR ispresented in

Figure8.

Figure8-ATRflowchart

4.2.5 System5:Electrolysis–EL

Fundamentallydifferentfromnaturalgasreformingiselectrolysisofwater.Bysupplyingasignificant

amountofelectricity,ELsplitswaterintohydrogenandoxygen.Acompletelycarbon-freeprocess.No

19

simulationofELhasbeenconducted,butthetechnicalandfinancialspecificationsareincludedinthe

thesisforcomparison.

Figure9-Electrolysisflowchart

4.2.6 System6:CombinedReformingandElectrolysis–CRE

Aselectrolysisofwaterproduceoxygenasaby-product,asystemofATRutilizingthisoxygenhasbeen

analysed.Replacingtheairseparationunitwithelectrolysersproducestherequiredamountofoxygen

totheATRaswellasadditionalhydrogen.TheCREsystemlayoutisshowninFigure10.

Figure10-CREflowchart

4.3 MethodologyandSimulationofLarge-scaleHydrogenProduction

Chapter 4 provides an overview of the different systems available for hydrogen production from

natural gas. This specific section will design andmodel themain systems suitable for large-scale

production,basedonexistingtechnology.Morespecifically,theyaredifferentmethodsforproducing

synthesisgas,alsoknownassyngas,agasmixconsistingmainlyofhydrogen,carbonmonoxideand

CO2.Theindividualprocessesproducesyngaswithdifferentpropertiesandcomposition,specialized

fortheirpurpose.Intheindustrytoday,SMRisawidelyusedmethodforhydrogenproduction[4].

However,asthescopeofthisthesishighlights,carboncaptureandstorage(CCS)isaprerequisitefor

a broad acceptance of fossil-based hydrogen in a sustainable industry. Given a goal of an energy

efficient hydrogen production process, which at the same timeminimizes the CO2 emissions, the

boundaryconditionsarechanged,henceSMRmightnotbethepreferablemethod.Thissectionwill

20

describethesixhydrogenproductionsystemsevaluatedinthisthesisandhowtheyaremodelledand

optimizedinAspenHYSYS.

4.3.1 GeneralDesignBasisandSimulationMethodology.

Thissectionwillprovidethedesignbasisfortheproductionsystemsandthemethodologyusedinthe

simulations.

4.3.1.1 Designconditions

AsmentionedinChapter3,aproductionof500tonnesofhydrogen/dayhasbeendefinedasthelarge-

scalescenarioanalysedinthisthesis.Thefeedstockusedinthehydrogenproductionsystemisnatural

gas(NG)ofthecompositionavailableatTjeldbergoddenindustrialcomplex.TheNGpropertiescanbe

seeninAppendixB.Thepropertiesofthehydrogenproducedinalltheproductionsystemsissetto

25°Cand20bar.

4.3.1.2 CO2Separationandhydrogenpurification

TheCO2separationandthehydrogenpurificationprocessesare,inallsystemspresentedinSection

4.2,modelled as component splitters, as seen in Appendix B. The only input parameters are the

productpurityandrecoveryrate.MDEAabsorptionforCO2separationandPSAforH2purificationis

chosenbasedonthetechnicaldatainTable2andthematurityofthetechnologiesavailable.Although,

giventhesameinputparameters,anytechnologywouldprovidethesametechnicalresultsinthese

simulations.

4.3.1.3 SystemHeatIntegration

All thesystemspresented inSection4.2aredesignedtobefullyheat integrated.Thesystemheat

integrationisfurtherelaboratedinAppendixB,wheretheheatintegrationdataispresented.

4.3.1.4 Energyefficiency

Inordertoevaluatethesystemperformanceandoptimizethehydrogenproduction,definingenergy

efficienciesisimportant.Thetwomainefficienciesusedinthisthesisareplantenergyefficiencyand

thermal efficiency, defined in equation 3.1 and 3.2, respectively. The plant energy efficiency

representstheoverallperformanceofthesystem,includingthepowerconsumptionofcomponents

like oxygen compressors and process water pumps. The specific power consumption of the CO2

compressionrelatedtostorageisnotincludedintheenergyefficienciesdefined,consideringtheCCS

21

system isoutof scope in this thesis.Expenditures related to investmentandoperationof theCCS

facilityis,ontheotherhand,includedinthefinancialanalysisinChapter5.

Plantenergyefficiency-/0:

12 = 4567% ∗ 97%

456:; ∗ 9:; +<=>?

(3.1)

ThermalEfficiency-/@:

1A = 4567% ∗ 97%

456:; ∗ 9:;

(3.2)

WhereLHVisthelowerheatingvalue,97Bisthemassflowrateoftheproducthydrogenand9:; is

the totalNG inlet, including both process feed and eventual furnace feed.<=>? is the net power

consumptionoftheproductionprocess.ThededicatedpowerconsumptionoftheCCSisnotincluded

intheefficiencies,sincethevalueshouldenableacomparisonoftheproductionprocessesspecifically.

Thethermalefficiencyisaratiodescribingtheenergypreservedintheproducthydrogencompared

totheNGfeed.AsallexcessheatissuppliedbyadditionalNG,aplantenergyefficiencysimilartothe

thermalefficiencyimpliesaprocesswithlittlepowerdemand.

4.3.1.5 AspenHYSYSSimulation

Thehydrogenproduction systems aremodelledwith the chemical process softwareAspenHYSYS

version8.6.HYSYSisspecializedinhydrocarbonprocessinganditisacomprehensivetool,enabling

designandoptimizationofsteadystateprocesses.Peng-Robinson(PR)ischosenastheequationof

state, which, similar to Soave-Redlich-Kwong, is well known for high performance in gas and

condensate systems. PR and all theHYSYS components used is further defined and elaborated in

AppendixB.

4.3.2 SteamMethaneReforming(SMR)

Asmentioned in Section 2.2.2, steammethane reforming is awidely usedmethod for converting

natural gas to syngas for hydrogen production. The SMR design and production results is further

22

elaboratedandanalysed in this section. TheHYSYSmodel and componentdesigns canbe seen in

AppendixB.

Table3-SMRdesignparameters

Value UnitsGas-heatedreformer:Temperature:Pressure:S/Cratio:

70025

0.25

°C

BarMole-H2O/Mole-C6

SMRreactor:Temperature:Pressure:S/Cratio:

950243

°C

BarMole-H2O/Mole-C6

HighTemperatureWGS:Temperature:Pressure:LowTemperatureWGS:Temperature:Pressure:

32023

19022.5

°C

Bar

°CBar

CO2Absorption:CO2recoveryrate:CO2purity:

95%

99.999%

mole/molemole/mole

PSA:H2recoveryrate:H2purity:

90%

99.999%

mole/molemole/mole

HydrogenProduct:Temperature:Pressure:

2520

°C

Bar

4.3.2.1 Pre-treatmentandGas-HeatedReformer

InSMR,desulphurizednaturalgasisfirstexpandedfrom50to25.5barandmixedwithsteampriorto

thegas-heatedreformer(GHR).S/CratioisintheGHRsetto0.3,sufficienttoreformalltheheavier

hydrocarbons.TheGHRfeedisheatedto400°C,withareformingpressureof24.75bar7.Thereformed

gasisleavingtheGHRatatemperatureof700°C.Thereformingefficiencyofheavierhydrocarbonsis

greater at “lower” temperatures around600-700°C 7. Theheat demand in theGHR is supplied as

6Mole-Cistheamountofcarbonatomsinthehydrocarbonsenteringthereformer.7InterviewwithJosteinSogge,Statoil

23

mentionedinSection2.2.1fromtheSMRproduct.AftertheGHRprocess,thegasisagainmixedwith

steampriortotheSMR,asseenfromthesystemflowchartinFigure5.S/Cratioissetto3,thistoget

anefficientreformingandtoavoidcarbonformationonthereformercatalysts8.Thegasisheatedto

700°CpriortotheSMRcolumns.

4.3.2.2 SMRReactor

TheSMRprocessisreformingnaturalgasat950°Cand24bar.AsmentionedinSection2.2.2,thegas

conversion rate is in SMR favouredby lowpressures andhigh temperatures. SMRbecomesmore

expensiveatlowerpressuresduetohighervolumeflowsandtheneedoflargerreactorcolumns.The

pressure used in industrial processing plants are therefore between 20-35 bar [8]. The reformer

temperaturereaches950°CandtherequiredheatissuppliedbyafurnaceburningNGandthePSA

tailgaswithair.ThereformedgasleavesthereformerwithH2/COratioofaround4.3.Thereformer

productisthencooleddownto320°CbeforeenteringtheWGScolumn.Thecoolingindonebyheat

exchangingtheSMRproductstreamwiththeGHRasmentioned,andbyheatingthewaterinputin

boththeGHRandSMR.

4.3.2.3 WGSandHydrogenPurification

WGSconversion is asmentioned in Section2.3 favouredby low temperatures,while the reaction

kineticsisfavouredbyhightemperatures[8].TheWGSisconductedintwostages,ahightemperature

shift(320°C)forfastreactionsandalowtemperatureshift(190°C)forhighconversion.WGSisthelast

gasconversionstepintheSMRprocessandthegasconsistsofmainlyH2andCO2.TheWGSproduct

iscooleddowntoafavourable25°CpriortotheCO2absorptionandthePSA.Separatorsareinstalled

priortotheCO2absorptioncolumnandthePSAtoavoidcondensateintheprocesses.CO2isremoved

inanabsorptioncolumnwitharecoveryrateof95%andleaveswithapurityof99.99%.Further,the

PSArecovers90%ofthehydrogen,withapurityof99.999%,asdescribedinSection2.5.1[8].The

pressuredropofthepurifiedhydrogenthroughthePSAis2barandthehydrogenproductleavesthe

PSAwithapressureof20barandatemperatureof25°C.Thetailgascontainingalltheremaining

hydrocarbons,nitrogen,waterandhydrogenexitsthePSAatapressureof2.5barand25°C.Thetail

gasisthenheatedupto500°Candfedasfueltothefurnace.

8InterviewwithRahoulAnantharaman,SINTEFEnergyResearch

24

4.3.2.4 Furnace

ThefurnaceisasmentionedsupplyingtheSMRwiththerequiredheatbyburningNGandthetailgas

withair.Therequiredairisheatedandsuppliedatatemperatureof335°Candapressureof1.2bar

while theNG and tail gas is heated to a temperature of 500°C before entering the furnace. Post

combustion,thefluegasleavesthefurnaceatatemperatureof1000°Candatatmosphericpressure.

Thefluegasiscooleddownto100°Csupplyingheattothereformingsystem.

4.3.2.5 ProcessOptimization–SMR

Inthisthesis,anoptimizedsystemhasasatisfyingenergyefficiency,naturalgasdemandandlowCO2

emissions,aswellasbeingcost-effective.TherearethreemainvariablestoadjustinSMRinorderto

achieve the desired specifications: reformer temperature, reformer pressure and S/C ratio in the

reformerfeed.Asmentionedearlierinthissection,SMRconversionisfavouredbyhightemperatures,

lowpressuresandhighS/Cratios.Ontheotherhand,highertemperatureandmoresteamimpliesa

higherheatdemand inthereactor.A lowerpressureresults in increasedvolumetric flowrateand

lower recovery rate in the PSA. In addition, there are technical boundary conditions in the

optimization.Duetotheriskofcarbonformationonthereformingcatalyst,S/Cratioof3issetasa

minimumvalue9.Thereformeroperatesatamaximumof950°Cduetomateriallimitations9.Pressure

levelsbetween20–35bariscommoninSMRplants,aswellasaminimumof20barisrequiredfora

satisfyinghydrogenrecoveryrateinthePSA[4].

Theoptimaltemperaturewasfoundtobeatthemaximum950°C,duetothesuperiorconversionrate.

Further,aS/Cratioof3wassetaswellasareactorpressureof24bar,theminimumvaluesufficient

tokeepthePSApressureat20bar.ThesystemwasfullyheatintegratedbyutilizingtheSMRproduct

andhotfluegastoproducesteampre-heatthefeedstreamsofthereactorandfurnace.Thisreduced

theNGdemand,henceincreasedtheplantefficiency.Sensitivitytodeviationfromoptimalconditions

isdiscussedin4.4.3.

4.3.3 SteamMethaneReforming,Improved(SMR+)

Inordertofurtherreducethecarbonemissions,thenaturalgasfeedtothefurnaceisreplacedby

producedhydrogen.Thus,theCO2emissionsperproducedhydrogenisfurtherreducedby60percent.


25

The carbon captured accounts for 90 percent of the produced CO2, making SMR+ an interesting

carbon-leansolution.

Table4-SMR+designparameters


70025

0.25

°C

BarMole-H2O/Mole-C10

SMRreactor:Temperature:Pressure:S/Cratio:

950243

°C



32023

19022.5

°C

Bar

°CBar


95%

99.999%

mole/molemole/mole

PSA:H2recoveryrate:H2purity:

90%

99.999%

mole/molemole/mole


2520

°C

Bar

4.3.3.1 DifferencesbetweenSMR+andSMR

The SMR+ hydrogen production plant consists of exactly the same components as the SMRplant

describedinsections4.3.2.1-4.3.2.4.Thedifferenceintheproductionmethodsistheinputtothe

furnace.InSMR+,someofthehydrogenproducedisburnedinthefurnaceinsteadofburningNG.This

isdonetoreducetheCO2emissionintheproductionplant.Foraproductioncapacityof500tonnes

ofhydrogen/dayusingSMR+,anextra184tonnesareproducedeverydaytosupplythereformerwith

asufficientamountofheat.ThiscanbeseeninTable13.Hence,theplantisinrealityproducing684

tonnes of hydrogen/day. Due to less available heat, the SMR+ feed stream is heated to 650°C,

comparedto700°CinSMR.

10Mole-Cistheamountofcarbonatomsinthehydrocarbons.

26

4.3.3.2 ProcessOptimization–SMR+

Asmentionedearlier,theconceptofSMR+istoreplacethefurnaceNGfeedwithproducedhydrogen

inordertoreduceCO2emissions.Thus,theoptimalSMRconditionsareusedinSMR+aswell. It is

possibletoachievehigherenergyefficiencieswithSMR+,butthatwouldresultinincreasedemissions

andtheconceptwouldbepointless.

4.3.4 PartialOxidation(POX)

Fundamentally different from SMR is the partial oxidation method of hydrogen production. As

explained in Section 2.2.3, a POX system combusts natural gas with limited supply of oxygen,

producinghydrogenandcarbonmonoxide.Asthemethodisapplicableonpracticallyallhydrocarbon

feedstock,thereisnoneedforaGHRinthePOXsystem.

Table5-POXdesignparameters

Value UnitsPOXreactor:Temperature:Pressure:O/Fratio:

1186

240.656

°C

BarMole-H2O/Mole-NG


32023

19022.5

°C

Bar

°CBar


95%

99.999%

mole/molemole/mole

PSA-1andPSA-2:H2recoveryrate:H2purity:

90%

99.999%

mole/molemole/mole


2520

°C

Bar

4.3.4.1 ASU

Theairseparationunit(ASU)neededinPOXandATRisinthisthesismodelledasablackboxwitha

specificpowerconsumptionof0.35kWh/Nm3ofoxygen,basedonaconventionalcryogenicASUby

LindeKryotechnik[28].Anoxygenpurityof100%isassumedaswellasatmosphericpressureanda

temperature of 25°C at the ASU outlet. Although the oxygen purity would be lower in practical

27

applications,nitrogenandotherinertgasesarenotaffectingthesimulations,hencetheirinclusionis

notnecessary.

4.3.4.2 POX

First,thenaturalgas(NG)isexpandedfrom50to24.5barandheatedupto500°CpriortothePOX

reformer. There is no need for desulphurizationwhen producing hydrogenwith POX, due to the

reformingprocessbeingnon-catalyticandhencesulphurwillnotdamagethereactor.Thereisalsono

needforapre-reformerduetoPOX’sabilitytoreformheavierhydrocarbons.Oxygenproducedinthe

ASUisheatedto250°Candcompressedintwostagesto24.5barbeforefedintothePOXreformer.

The reformer is modelled as an adiabatic reactor, and since the POX reaction is exothermic, the

reforming product leaves the reformer at a temperature of 1186°C. All theNG hydrocarbons are

reformed, asdescribed in Section2.2.3, resulting inmainlyH2, CO,H2O leaving the reformer. The

productstreamiscooleddownto320°CpriortoWGS.

4.3.4.3 WGSandPurification

WGSis,asinSMRandSMR+,doneintwotemperaturestages.This,asmentionedinSection4.3.2.3,

togetfastreactionsandhighconversion.Thetwotemperaturestagesconvertthegasat320°Cand

190°Catapressureof23and22.5bar.ThefluidleavingtheWGSisthencooleddownto25°Cpriorto

theCO2absorptionandPSA.TheCO2absorptionisalsodonesimilarlytoSMRandSMR+andabsorb

CO2witharecoveryrateof95%andwithapurityof99.999%.Aseparator is installedpriortothe

absorption column and the PSA to prevent condensate entering the columns. The hydrogen

purificationisdonewithtwoPSAstages,inordertorecovermoreofthehydrogenproduced.Thetail

gasafterthefirstPSAisstillcontainingmuchhydrogen,andsincethetailgasisnotutilisedinPOXas

inSMR(furnace) thetailgas is fedtoanotherPSAandmorehydrogen is recovered.BoththePSA

stagespurifyhydrogenwitharecoveryrateof90%andproduceshydrogenwithapurityof99.999%.

The PSA systems are operating and delivering hydrogen at a temperature of 25°C and at 20 bar.

Producedtailgasisburnedinafurnacetoprovideadditionalheattothesystem,resultinginsome

CO2emissions.

4.3.4.4 ProcessOptimization–POX

InPOX,theoxygen-to-fuel(O/F)ratiodecidesthetemperatureinthereactor,notanexternalheat

supply. Therefore, the system is optimized by varying oxygen flow rate and pressure level in the

reactor. In this thesis, the “fuel” valueused in theO/F ratio is the flow rateof themainNG feed

enteringthesystem.ThereisnodedicatedsteamfeedintothePOXreactor,althoughsomesteamis

28

addedpriortothereactors.Moreoxygenresultsinmorecombustion,higherconversionandahigher

temperature.Toomuchoxygen,andthetotalcombustionreactionwillbegintodominateandless

hydrogenwillbeproduced.1500°C issetasaupper limit inthereactoroutlet [4],duetomaterial

limitations.AswithSMR,thesystempressurebalancebetweenenergyefficiencyandvolumetricflow

rate.

ThepressureinthePOXreactorissetto24bar,tokeepthePSApressureabove20bar.Further,the

systemisoptimizedbyadjustingtheO/Fratiotomaximizetheenergyefficiency.Atoptimalconditions

thetemperatureis1186°CinthereformerproductandtheO/Fratiois0.656.

4.3.5 AutothermalReforming(ATR)

AsdescribedinSection2.2.4,ATRisacombinationofnon-catalyticPOXandSMR.Table6showsthe

maindesignparametersofthesystem,andtherestofthissectionwilldescribethesystemlayoutand

optimizationstepsindetail.

Table6-ATRdesignparameters


70025

0.25

°C


ATRreactor:Temperature:Pressure:S/Cratio:O/Fratio:

1020

241.5

0.616

°C

BarMole-H2O/Mole-C11Mole-H2O/Mole-NG


32023

19022.5

°C

Bar

°CBar


95%

99.999%

mole/molemole/mole


90%

99.999%

mole/molemole/mole

11Mole-Cistheamountofcarbonincludingallthehydrocarbons.

29


2520

°C

Bar

4.3.5.1 ASU

TheASUusedintheATRismodelledsimilarlyasinPOX,describedinSection4.3.4.1.TheASUhasa

specificpowerconsumptionof0.35kWh/Nm3ofoxygen,producingclosetopureoxygen[28].

4.3.5.2 GHRandATR

First,desulphurizedgas isexpandedto25bar,mixedwithsteamandheatedto400°Cpriortothe

GHR.TheGHRinATRisalsomodelledsimilarlyasinSMRandSMR+,describedinSection4.3.2.1.The

GHRfeedispre-heatedto400°Catapressureof24.5bar.AS/Cratioof0.25isset,sufficienttoreform

the heavier hydrocarbons. TheGHR heat demand is supplied by cooling the ATR product stream,

demonstrated inFigure8.Ata temperatureof700°C, theGHRproduct ismixedwithmoresteam

beforeenteringtheATR.Thesteamhasatemperatureof350°Candthefinaltemperatureofthefeed

gasenteringtheATRbecomes563°C.AsseenfromTable6,theS/CratiointheATRfeedissetto1.5.

Thelargeamountofsteamintheprocessisneededtopreventcarbonformation.

OxygenisfedtotheATRreactorasaseparatestreamatatemperatureof250°Candatapressureof

24.5bar.Theoxygencompressionisdoneinatwo-stagecompressorwithintercooling.Asmentioned

inSection2.2.4,ATRisacombinationofnon-catalyticPOXandSMR.TheATRreactorisadiabaticand

theheat requiredby theSMR reactions is suppliedby thePOX reactions. The temperatureof the

reformingproductisdirectlydependentontheamountofoxygenfedtotheATR.Theoxygen-to-fuel

(O/F)ratioisintheATRsetto0.616,asseeninTable6,andthetemperatureofthereformingproduct

becomes1020°C.Inthisthesis,the“fuel”valueusedintheO/FratioistheflowrateofthemainNG

feedenteringthesystem.Thereformingpressure issetto24bar.TheATRprocessoptimizationis

furtherelaboratedinSection4.3.5.4.Further,theATRproductstreamiscooleddownto320°Cprior

tothefirstWGSstage.TheATRproductiscooledbytheGHRbetween1000–750°Candwithwater

between750-320°C.PriortoWGS,thegasstreamisalsomixedwithmoresteam,asseenfromFigure

8,resultinginhigherconversionofCOintheWGSreactors.

4.3.5.3 WGSandPurification

WGSis,asinSMR,SMR+andPOX,doneintwotemperaturestagestoachievefastreactionsandhigh

conversion,asmentionedinSection4.3.2.3.Thetwotemperaturestagesconvertthegasat320°Cand

190°Catapressureof23and22.5bar.AftertheWGS,thegasstreamiscooleddownto25°Cpriorto

30

theCO2absorptionandPSA.TheCO2absorptionisdoneinthesamewayasinSMR,SMR+andPOX,

witharecoveryrateof95%andwithapurityof99.999%,asseenfromTable6.Aseparatorisinstalled

priortoboththeabsorptioncolumnandthePSAtopreventcondensateenteringthecolumns.The

hydrogenpurificationinATR,aswellasinPOX,donewithtwoPSAcolumns,thistorecovermoreof

thehydrogenproduced.ThetailgasafterthefirstPSAis,asinPOX,compressedandfedtoasecond

PSAtorecovermorehydrogen.ThesystemflowchartcanbeseeninFigure7.BoththePSAcolumns

purifyhydrogenwitharecoveryrateof90%andproduceshydrogenwithapurityof99.999%.The

PSAsareoperatinganddeliveringhydrogenat25°Cand20bar.AswithPOX,thefinaltailgasstream

isburnedinafurnacetoproduceadditionalheattothesystem.

4.3.5.4 ProcessOptimization-ATR

ThemainprocessdesignvariablesinATRaretheO/Fratio,theS/Cratioandpressure,affectingthe

overallsystemsimilarlyasinSMRandPOX.Moreoxygenfavoursmorepartialoxidation,providing

more heat for the steam reforming reactions. Toomuch oxygen results in total combustion, less

hydrogenproductionandtemperaturesaboveamaximumof1150°C[4].Duetosootformation,aS/C

ratiobelow1.5 isnotpossiblewithcurrent technology12.Thesamepressure limitationsas inSMR

existsinATR,witharequiredPSApressureabove20bar.

Allvariablesisadjustedinordertoachieveamaximizedplantenergyefficiency,definedinSection

4.3.1.4. An important notewith ATR is that, regardless of oxygen flow rate, the globalmaximum

energy efficiency was found at a S/C ratio below 1.5, which is a minimum value due to reactor

operation.Hence,theS/Cratiowassetto1.5andtheprocesswasthenoptimizedbyadjustingthe

oxygen flow rate. The O/F ratio was found to be 0.616 on amole basis. Because of the internal

combustion,theoxygenratioalsodeterminesthereactortemperature,at1020°C.SimilartoSMR,the

reforminginATRisalsofavouredbylowpressures.Therefore,thepressurehasbeensettoaminimum

of24barinordertokeeptheprocessstreamabove20barinthefinalPSAunit.

Furtheroptimizationof thesystem, lookingat thepossibilityof recompressing theprocessstream

afterthereactor,wouldopenforpressuresbelow24bar.Thisisnotdoneinthisthesisduetolimited

costdataofsuchacompression,asitwouldimplyasignificantincreaseofthevolumetricflowratein

thereactor.


31

4.3.6 ElectrolysisofWater(EL)

Asabenchmarkinthecomparisonofthedifferenthydrogenproductionmethods,electrolysisofwater

representsaclean,zero-emissionalternative.Infuturescenarios,iftheelectricitypricescontinueto

drop, electrolysis can potentially be the most cost-efficient solution for large-scale production.

Therefore, electrolysis is included in the thesis, although not simulated. The specifications of the

electrolysisplantusedinthisreportislistedinTable7.Itisimportanttohighlightthatthespecific

plant power consumption is the average power consumption of all components in the facility,

includingcompressors,pumpsandtheeffectofcellstackdegeneration.Normally,supplierslistthe

power consumption only of the electrolyser stacks with newly activated catalysts. Typically, the

catalystsarereplacedevery7-9yearswithadegenerationinperformanceataround10%atthetime

ofre-activation13.ThepowerconsumptionisfurtherelaboratedinAppendixB.

Table7-Technicalspecificationsofelectrolysis[29].

Electrolysis UnitCD (LHV-basis): 62.0

SpecificPlantPowerconsumption:

4.85 kWh/Nm3

SpecificPlantPowerconsumption:

53.9 kWh/kgH2

Totalpowerdemand: 961.54 MW

Electricitydemand: 8.0 TWh/year

H2Produced: 500 Tonnes/day

Itisimportanttohighlightthesignificantelectricitydemandofalarge-scaleelectrolysisfacility.With

aspecificpowerconsumption,includingauxiliarycomponents,of53.9kWhperkilogram,theannual

demand is 8.0 TWh, operating 347 days a year. In comparison, the total energy consumption in

Norwaywas234TWhin2014[30].

4.3.7 CombinedReformingandElectrolysis(CRE)

Basedonthesystemsdescribedinthischapter,oneadditionalsystemisevaluated.WhatiftheASU

inanautothermalreactorisreplacedbyelectrolysis,co-producinghydrogen?Thatistheconceptof

thecombinedreformingandelectrolysis(CRE)system.Keepingthe500tonnesperdaycapacity,but

13InterviewwithSalesDirectorofNEL-Hydrogen,HenningLangås,28/10–2016.

32

splittheproductionintwoparallelsystems.Withtheelectrolysersproducingtheamountofoxygen

theATRreactordemands, theresultingsplitofproduction isapproximately30%fromELand70%

fromATR.This further reduces thecarbon footprintofATRaswellas it improves the flexibility to

feedstockcostvariations.Theelectrolysersareassumedtoproducetheexactstoichiometricamount

ofoxygenperamountofhydrogen.KeydesignparametersarelistedinTable8.

Table8-CREdesignparameters


70025

0.25

°C


ATRreactor:Temperature:Pressure:S/Cratio:Oxygen-to-NGratio:

1004

241.5

0.607

°C

BarMole-H2O/Mole-C11Mole-H2O/Mole-NG


32023

19022.5

°C

Bar

°CBar


95%

99.999%

mole/molemole/mole


90%

99.999%

mole/molemole/mole


2520

°C

Bar

4.3.7.1 ProcessOptimization-CRE

TheATR system inCRE is very similar to theonedescribed inSection4.3.5,only replacing theair

separationunit,andreducingtheoutput.TheELsystemwillbeidenticaltoSection4.3.6.Themain

deviationisthattheprocessoptimizationofCREisdonebasedontheoverallefficiency,includingthe

electrolysers. This results in a slightly lower O/F ratio due to the relatively low efficiency of the

14Mole-Cistheamountofcarbonincludingallthehydrocarbons.

33

electrolysisplant.TheS/Cratioremainsat1.5andtheO/Fratioisfoundtobe0.607.Theexactsplit

ofproductionis362and138tonnesperdayinATRandElectrolysis,respectively.

4.4 TechnicalResultsandDiscussion

Presentinganoverviewofthedifferentproductionmethods,thissectionwillevaluatewhichmethod

ispreferableforalarge-scalefacilityinNorwayfromatechnicalpointofview.Thekeyperformance

parametersevaluated,asmentionedinthebeginningofthischapter,areenergyefficiencyandCO2

emissions. Thenatural gasprocess feed is also key, due its impacton the sizingof theplant. It is

importanttohighlightthateconomicviabilityhasbeentakenintoconsiderationwhiledesigningthe

systems.

Table9-Overviewofthesimulationresults,comparingtheindividualproductionsystems.AllefficienciesareLHV-based.

Unit SMR SMR+ POX ATR EL CREPlantEnergyefficiency,CD:

- 0.82 0.78 0.78 0.82 0.62 0.75

ThermalEfficiency,CE:

- 0.82 0.78 0.81 0.84 - -

NaturalGasConsumption:

Stdm3/h 78826 82844 79753 76776 - 55630

SpecificNaturalGasconsumption:

Stdm3NG/kgH2 0.158 0.167 0.160 0.154 - 0.111

Reformerconversionrate15:

Mole-H2/mole-NG 3.40 3.40 1.97 2.36 - 2.36

H2/COratiointhereformingproduct:

Mole/mole 4.12 4.12 1.71 2.69 - 2.73

S/Cratiointhereformer16:

Mole/mole 3 3 0 1.5 - 1.5

O/Fratiointhereformer:

Mole/mole 0 0 0.656 0.616 - 0.607

PowerDemand(excl.CCS):

MW 2.03 2.30 29.8 27.1 962 335.2

HeatDemand: GJ/h 1897.0 2445.3 754.6 887.7 - 642.7

WaterDemand17: Kg/h 108550 139421 60075 63667 208565 104068CO2Captured: Tonnes/day 3047 3913 3931 3816 - 2752CO2Emitted: Tonnes/day 1198 547 363 318 - 244H2Produced: Tonnes/day 500 500 500 500 500 500

15Theamountofhydrogen in thereformerproductpermoleNGfedtothereformingsystem.NGfedto furnace isnotincluded.16Mole-Cistheamountofcarbonincludingallthehydrocarbons.17Waterdemandistheprocesswatersuppliedminusthewaterrecirculatedinthesystem.

34

4.4.1 EnergyEfficiency

With regards to plant energy efficiency, ATR and SMR represent the best alternatives. Here, it is

importanttomentionthegeneralconsensusregardingSMRasthemostenergyefficientmethodto

producehydrogenfromnaturalgas.OursimulationsshowthatATRisequallyefficient.Onepossible

explanationtothisisthat,aswithPOX,thenon-catalyticpartialoxidationoccurringwithinthereactor

chamberdoesnotnecessarilyreachequilibriuminrealoperation.HYSYS,ontheotherhand,assumes

instantequilibrium.Notachievingequilibrium,moreoxygenwouldbenecessarytoprovideenough

heat for the steam reforming and the efficiency would drop. SMR+ shows a decrease in energy

efficiencyinordertoincreasetheCO2capture.Comparedtonaturalgasreformingelectrolysishasa

considerablylowerenergyefficiency.CombinedwithATR,theresultimproves,butisstillinferior.Itis

importanttohighlightthattheuseoflowerheatingvalue(LHV)inthecalculationofefficienciesaffect

thevalueinelectrolysismorethaninthereformingprocesses,duetothefactthatthefeedNGalso

use LHV. On a HHV-basis, SMR and electrolysis have a plant energy efficiency of 0.87 and 0.73,

respectively.

4.4.2 CO2emissions

AscanbeseeninFigure11,ATRrepresentsthetraditionalnaturalgasreformingalternativewiththe

lowestcarbondioxideemissions.AlthoughSMRandATRproducesasimilaramountofCO2theinternal

combustion of ATR enables superior carbon capture and hence a significantly reduced footprint,

comparedtoSMR.SMR+andPOXalsoseemtobegoodalternativestoproducecarbon-leanhydrogen

with a significant reduction from the standard SMR. The alternatives involving electrolysis are

naturallyproducingfarlessCO2,butareontheotherhandconsumingmoreelectricity.Asaresultof

Norway’svasthydropowerresources,electricityisconsideredzero-emissionenergy,asshowedinthe

figure.Elsewherethisisnotnecessarilythecase,affectingtheviabilityofthesolution.

Inordertofurtherreduceemissions,improvementoftheCO2recoveryrateintheabsorptioncolumn

canbeimportant.95%isusedinthisanalysis,leavingroomforimprovement,especiallyinATR,SMR+

andPOX,wheretheonlyemissionscomefromtheburnedtailgas.InSMR,post-combustionCCSwill

beimportantinthefuture,toapproachzero-emission.Pre-combustionCCSislimitedtoaround70%

captureinenergyefficientSMR.

Mitigatingclimatechangeisoneofthemainreasonsastowhyhydrogenproductionisaninteresting

prospect.Hence,targetingclosetozeroemissionsisimportant.Ontheotherhand,thetechnology

has to be economically viable in order to be implemented. Aswill be highlighted in the financial

35

analysisinChapter5,analysingtheseproductionmethodsprovidesacostofincreasedCO2capture,

whichisbeneficiaryinfutureinvestmentdecisions.

Figure11-CO2overview.Thisblockdiagramshowstheamountofcarbondioxidecapturedfromthesyngasstream.TheemittedCO2ofATRandCREiscalculatedfromthecarboncompositionofthePSAtailgas.

Figure11presentstheCO2captureandemissionsofthedifferentsystems.Excludingpost-combustion

CCS,SMRistheinferiorhydrogenproductionmethodwithregardstocarbonfootprint.Electrolysis

fromNorwegian,renewableenergy isassumedcarbon-free,enablingazero-emissionproduct. It is

alsoimportanttomentiontherisksofcarbonstorage.Knowledgeoftheeffectabreachinstorage

reservoircancauseislimited.Theby-productofelectrolysis,ontheotherhand,ispureoxygen.CRE

representsasolutionwithfurther30%reductioninemissioncomparedwithATR,aswellasreducing

theneededCCSwith30%.

4.4.3 SMRResultsandDiscussion

AsTable9shows,SMRhasanenergyefficiencyof0.82,aconversionrateof3.47,aswellasalow

powerdemand.Ontheotherside,ithasthemostCO2emissionsofthesystemsanalysedinthisthesis.

This section will elaborate on the results of the SMR simulations, as well as discuss the systems

sensitivitytochangesindesignvariables.

Table 10 provides a simulation overview, providing information of the stream properties and

compositionthroughtheproductionprocess.Ascanbeseen,theGHRworkasapre-heateraswellas

36

itreformsmostoftheheavierhydrocarbons.AlthoughsomehydrogenisproducedintheGHR,more

than70%isproduceddirectlyintheSMRreactor.

Table10-SMRSimulationOverview.Thistableshowsthestreampropertiesandcompositionthroughtheproductionprocess.ItishelpfultolookatFigure5togettheoverviewwhilestudyingthistable.

NGFeed GHRFeed SMRFeed

with

steam

WGS

Feed

CO2

Absorptio

nandPSA

Feed

TailGas Hydrogen

Product

Airto

Furnace

NGto

Furnace

FlueGas

Temperature[°C]: 50 400 700 320 25 25 25 335 500 1000

Pressure[Bar]: 50 25.25 24.5 23.5 22.5 2.5 20 1.2 50 1.2

Vapourfraction: 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0

Moleflow[kmole/h]: 2728 3546 12523 17656 14803 1579 10334 11439 606 13092

Massflow[kg/h]: 53613 68356 213548 213550 162005 14132 20833 330022 11908 356058

Moleflow[kmole/h]:

CH4

H2

CO

CO2

H2O

C

C2H6

C3H8

i-Butane

n-Butane

i-Pentane

n-Pentane

n-Hexane

n-Heptane

n-Octane

N2

O2

2327.48

0.00

0.00

60.29

0.00

0.00

192.32

74.34

14.87

25.64

7.37

7.23

4.91

3.55

1.09

8.87

0.00

2327.48

0.00

0.00

60.29

818.38

0.00

192.32

74.34

14.87

25.64

7.37

7.23

4.91

3.55

1.09

8.87

0.00

2771.88

906.43

355.18

163.78

8315.64

0.00

1.30

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

8.87

0.00

208.20

9272.33

2253.12

832.12

5081.02

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

8.87

0.00

208.20

11482.22

43.18

3036.16

24.34

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

8.87

0.00

208.20

1148.22

43.18

151.81

18.78

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

8.87

0.00

0.00

10334.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

9036.90

2402.21

516.94

0.00

0.00

13.39

0.00

0.00

42.71

16.51

3.30

5.70

1.64

1.61

1.09

0.79

0.24

1.97

0.00

0.00

0.00

0.00

1134.67

2892.03

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

9047.74

17.71

ThetablealsodisplayshowtheWGSreactorsshiftmostoftheCOtoCO2.Althoughnotincludedin

theflowcharts,separatorsare located infromofboththecarbonabsorptioncolumnandthePSA.

ThatexplainsthereductioninwatercontentbetweentheWGSfeedandthePSAfeedinthetable.

Inordertodesignawelloperatingsystem,thesensitivitytokeyvariablesrequiresattention.Howthe

systemrespondstochangesintemperatureisthoroughlypresentedinTable11.

Table11-PresentationofhowSMRparameterschangebychangingthereformingtemperature.Thechosendesignvaluesarehighlighted.

Property Unit

Temperature: °C 700 750 800 850 900 950 1000

S/Cratio: mole/mole 3 3 3 3 3 3 3

Conversionrate: Mole_H2/mole_NG 1.723 2.123 2.534 2.914 3.211 3.399 3.493

37

ReformingNGflow: Sm3/h 143601 112885 91708 77731 69190 64501 62189

SMRflow: Sm3/h 659223 518218 421002 356836 317628 296101 285488

SMRHeatdemand: GJ/h 421 522 592 642 681 715 747

TailGasflow: kmole/h 5373 3893 2875 2206 1800 1579 1471

LHVTailGas: kJ/kmole 650650 594643 522140 437196 353788 289508 250620

NGdemandfurnace: Sm3/h 0 0 0 1282 9696 14326 18812

TotalsystemNGdemand: Sm3/h 143601 112885 91708 79013 78886 78826 81001

CO2emission: Tonnes/day 4415 2859 1789 1154 1181 1198 1327

Hydrogenproduced: kg/day 500000 500000 500000 500000 500000 500000 500000

PlantEnergyefficiency: - 0.448 0.571 0.704 0.817 0.819 0.819 0.797

ExcessHeat18: GJ/h 2409.9 1263.0 472.9 0.0 0.0 0.7 84.4

Aspreviouslymentioned,theconversionrateincreasesathigherreformingtemperatures.Because

thesystemisheatintegratedtofit950°Cinthereactoroutlet,variationsintemperaturewillcause

excessheatoradditionaldemand.TheextraheatdemandissuppliedbyincreasingtheNGfeedtothe

furnace,hencereducingtheefficiency.Itisimportanttohighlightthatatthetemperatureswithexcess

heat, thesystemisnotheat integratedfurtherthanthedesigncase. If technologicaldevelopment

allows for temperaturesup to1000°C,onemaybeable to achieveevenbetteroperation,due to

further improvements on heat integration. Table 11 shows that the energy efficiency is close to

constantbetween850 -950°C.Therefore, theupper limit is chosen to reduceprocess flowwhich

resultsinlowerinvestmentcostsaswillbediscussedinSection5.3.6.

Figure 12 highlights the sensitivity of the conversion rate and energy efficiency to temperature

changes.Eventhoughtheplantenergyefficiencyisstablebetween850–950°C,theconversionrate

increaseswithtemperature,whichleadstolowerNGfeedtotheprocess.MoreNGwillbeneededin

thefurnace,thustheefficiencyisclosetoconstant,butasthefinancialanalysiswillhighlight,higher

NGfeedtothereactorimplieshigherCAPEX.

18ExcessHeat=TotalHeatAvailable–TotalHeatDemand

38

Figure12-HowthePlantEnergyEfficiencyandthereformingConversionRateischangingwithdifferenttemperaturesinSMR

AdjustingtheS/Cratiowhilekeepingthetemperatureconstantisalsoimportanttounderstandthe

systembehaviour.Reducingthesteamflowtoaratioof2-2.5willincreaseefficiencyasshowninTable

12.Thisismainlyduetothereducedheatdemandfortheprocessstreamtoreachthesetreformer

temperature.AsSection4.3.2.5explains,aS/Cratioof3isnecessarytoadequatelypreventcarbon

andsootformation,whichwillreducetheactivityofthecatalyst.Hence,theminimumratioof3was

chosen.EnablingaS/Cratiobelow3willprovideslightlybetterenergyefficiency.Itwillalsoreduce

theconversionrateandhenceincreasetheNGprocessflow.Ontheotherhand,alowerS/Cratiowill

reducethetotalvolumeflowthroughtheSMR,whichisbelievedtoreducethetotalsystemCAPEX,

furtherelaboratedinChapter5.

Table12-HowSMRparameterschangebychangingtheS/Cratiointhereformer.Thechosendesignvaluesarehighlighted

Property Unit

Temperature: °C 950 950 950 950 950 950 950

S/Cratio: mole/mole 1 1.5 2 2.5 3 3.5 4

Conversionrate: mole_H2/mole_NG 2.334 2.769 3.056 3.254 3.399 3.508 3.594


SMRflow: Sm3/h 260750 245629 251753 271870 296101 322261 349590




39


TotalsystemNGdemand:

Sm3/h 101917 80101 78614 78781 78826 79130 79516



Plantenergyefficiency: - 0.633 0.806 0.822 0.820 0.819 0.816 0.812

ExcessHeat19: 1012.5 99.7 0.0 0.0 0.7 12.0 26.7

Heatintegrationhasalargeimpactontheplantenergyefficiency.InSMR,thisisdonebyusingheat

exchangers in all the cooling processes. This allows the reformer and furnace feed streams to be

heatedtohighertemperatures,resultinginalowerNGdemandduetoalowerheatdemandinthe

reformerandmoreefficientcombustioninthefurnace.

Figure13-HowtheplantenergyefficiencyandtheconversionrateischangingwithpressureinSMR

Figure13displayshow the systempressureaffects theprocessperformance.As canbe seen, the

pressuremerelyaffectstheefficiency,althoughtheconversionrateisreducedathigherpressures,

Thisisduetothemethaneslipincreasingtheheatingvalueofthetailgas.Theprocessnaturalgas

flowincreaseswithhigherpressure,butthefurnaceinputdecreases.


40

Sincethisthesisonlyconsiderspre-combustioncarboncapture,someCO2emissionwilloccurinSMR.

Areducedheatdemandinthereformer,andthenceareducedNGinputinthefurnace,canreduce

theemissionstosomeextent. Ifpossible,areduction inthereformingS/Cratiowouldreducethe

reforming heat demand. In addition, a more efficient furnace would improve the heat transfer,

reducingtheNGinputinthefurnace.

SMRachievesa totalplantefficiencyof0.82onaLHV-basis,whichcorrespondswellwithexisting

literature.TheNationalRenewableEnergyLaboratory(NREL),whichalsohavedoneasimilaranalysis

ofSMR,endedupwiththesameplantefficiencyof0.82[31].ThehydrogenRoadmapmadebyIEA

estimatestheplantefficiencyofSMRtobebetween0.70–0.85,whichsupportstheviabilityofthe

findingsinthisthesis.TheH2/COratiooftheSMRreformingproductof4.3isalsosupportedbyother

journalsthatestimatestheH2/COratioinSMRtobebetween3.5-5.5[10].

4.4.4 SMR+ResultsandDiscussion

SMR+issummarizedbylowerCO2emissionsthanSMRattheexpenseofhighernaturalgasdemand

andhencealowerenergyefficiency.Onemayarguethatburningapremiumproduct,suchaspure

hydrogeniswasteful,butitisaninterestingalternativeinordertoreducetheCO2emissions.Alsoas

asolutionforfurtherreductioninexistingSMRplants.Table13showsthesimulationoverviewfor

SMR+,which ingeneraloperatesverysimilarly toSMR.Themaindifference is theextrahydrogen

producedtothefurnace,increasingthetotalmassflowthroughtheprocess.

Table13-SMR+SimulationOverview

NGFeed GHRFeed SMR+

Feed

WGS

Feed

CO2

Absorptio

nandPSA

Feed

TailGas Hydrogen

Product

Hydrogen

toFurnace

Airto

Furnace:

FlueGas

Temperature[°C]: 50 400 650 320 25 25 25 500 335 1000

Pressure[Bar]: 50 25.25 24.5 23.5 22.5 2.5 20 19.75 1.2 1.2

Vapourfraction: 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0

Moleflow[kmole/h]: 3504 4555 16085 226767 19013 2028 10334 2939 13367 16100

Massflow[kg/h]: 68860 87796 274279 274281 208077 18151 20833 5925 385644 409715

Moleflow[kmole/h]:

CH4

H2

CO

CO2

H2O

C

C2H6

C3H8

2989.40

0.00

0.00

77.43

0.00

0.00

247.01

95.48

2989.40

0.00

0.00

77.43

1051.12

0.00

247.01

95.48

3560.18

1164.21

456.19

210.35

10680.54

0.00

1.67

0.00

267.40

11909.29

2893.89

1068.77

6526.01

0.00

0.00

0.00

267.40

14747.65

55.46

3899.60

31.26

0.00

0.00

0.00

267.40

1474.76

55.46

194.98

24.13

0.00

0.00

0.00

0.00

10333.99

0.00

0.00

0.00

0.00

0.00

0.00

0.00

2938.89

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

517.85

4972.60

0.00

0.00

0.00

41

i-Butane

n-Butane

i-Pentane

n-Pentane

n-Hexane

n-Heptane

n-Octane

N2

O2

19.10

32.94

9.46

9.28

6.31

4.55

1.40

11.39

0.00

19.10

32.94

9.46

9.28

6.31

4.55

1.40

11.39

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

11.39

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

11.39

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

11.39

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

11.39

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

10560.00

2807.09

0.00

0.00

0.00

0.00

0.00

0.00

0.00

10571.39

37.70

Table14presentsthesensitivitytovariationsinthereformertemperature.SimilartoSMR,SMR+also

hasahigherconversionratioathighertemperatures.An importantresult ishowtheplantenergy

efficiencyincreasesifthetemperatureisreducedto850°C,attheexpenseofclosetodoubledCO2

emissions.ThisoccursbecausethesystemoperatesasastandardSMRwhenthetailgasissufficient

tosupplytheheatdemandedbythereformer.Theeffectofusingadditionalhydrogendiminish,and

theemissionsincrease.AsthesystemslogicisbasedonreplacingthefurnaceNGfeedwithhydrogen,

itisimportanttokeeptheoptimalreformertemperatureandS/CratioasinthestandardSMR.Ifthe

temperaturedropsinthereactoroutlet,theconversionratedropsandtheemissionsincrease.That

isanimportantresultasitistheoppositeofSMR,whereattemperaturescloseto950°C,theemissions

increasewithhigher conversion rates.Theeffectof temperaturechangeson theemissions isalso

presentedinFigure14.

Table14 -PresentationofhowSMR+parameterschangebychangingthereformingtemperature.Thedesignvaluesarehighlighted.

Property Unit

Temperature: °C 700 750 800 850 900 950 1000

S/Cratio: mole/mole 3 3 3 3 3 3 3



SMRflow: Sm3/h 659223 518218 421002 364028 373509 380118 398158









ExcessHeat20: GJ/h 2410.0 1263.1 472.9 0.0 0.0 0.8 92.8


42

Figure14-GraphshowinghowtheplantenergyefficiencyandCO2emissionsareaffectedbychangesinreformertemperatureinSMR+.

InTable15,theS/Cratioisvaried,keepingthereformertemperatureat950°C.Here,theresultsare

quitesimilartoSMR,withahigherconversionratefromincreasedsteamflow.ReducingtheS/Cratio,

theefficiencyincrease,aswellastheCO2emissions.Therefore,ifSMR+istoretainitslowemissions,

keepingthereformertemperatureandS/Cratioondesignconditioniskey.

Table15-HowSMR+parameterschangebychangingtheS/Cratiointhereformer.Thedesignvaluesarehighlighted.

Property Unit

Temperature: °C 950 950 950 950 950 950 950

S/Cratio: mole/mole 1 1.5 2 2.5 3 3.5 4



SMRflow: Sm3/h 260750 245629 288134 334860 380118 427350 475062








43


ExcessHeat21: GJ/h 1012.5 99.8 0.0 0.0 0.8 16.4 33.8

4.4.5 POXResultsandDiscussion

Utilizing the partial combustion of NG, the POX reformer operates exothermically at high

temperatures.Ataround1300°C,theplantenergyefficiencyis0.78withaCO2emissionlevelof363

tonnesperdaywithmaximalpre-combustioncarboncapture.TheO/Fratioandthepressurearethe

onlymainprocessdesignvariables.Table16showsthesimulationoverview.

Table16-POXSimulationOverview

NGFeed POXNG

Feed

POXO2

Feed

POX

product

WGS

Steam

Feed

CCSand

PSA1

Feed

PSA2

Feed

TailGas Hydroge

n

Product

Airto

Burner

FlueGas

Temperature[°C]: 50 500 250 1186 320 25 25 25 25 350 1000

Pressure[Bar]: 50 24.5 24.5 24 23.25 22.25 22 2.5 20 1.2 1.2

Vapourfraction: 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0

Moleflow[kmole/h]: 3373 3373 2213 11189 5840 14539 1401 461 10334 1255 1635

Massflow[kg/h]: 66290 66290 70814 137104 105199 197284 14135 12241 20833 36198 48438

Moleflow[kmole/h]:

CH4

H2

CO

CO2

H2O

C

C2H6

C3H8

i-Butane

n-Butane

i-Pentane

n-Pentane

n-Hexane

n-Heptane

n-Octane

N2

O2

2877.84

0.00

0.00

74.54

0.00

0.00

237.80

91.91

18.38

31.71

9.11

8.94

6.07

4.38

1.35

10.96

0.00

2877.84

0.00

0.00

74.54

0.00

0.00

237.80

91.91

18.38

31.71

9.11

8.94

6.07

4.38

1.35

10.96

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

2212.92

89.56

6627.18

3869.24

113.41

478.87

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

10.96

0.00

0.00

0.00

0.00

0.00

5839.51

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

89.56

10438.38

57.99

3917.98

24.60

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

10.96

0.00

89.56

1043.84

57.99

195.88

2.32

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

10.96

0.00

89.56

104.38

57.99

195.88

2.32

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

10.96

0.00

0.00

10334.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

991.19

263.48

0.00

0.00

0.00

343.44

285.84

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

1002.15

3.16

DifferentfromSMRandSMR+,thereformertemperatureinPOXissetbyadjustingtheoxygenfeed.

Increased O/F ratio provides more exothermic oxidation resulting in a higher temperature, and

increased conversion up to a pointwhere total combustion starts to dominate. Balancing on this


44

optimalpointofoperationmaybedifficult,butbasedontheHYSYSanalyses,POXisenergyefficient

withlimitedemission.Table17showshowthesystemrespondstochangesinO/Fratio,highlighting

theoptimalvalueof0.656.Ascanbeseen,theenergyefficiencyisequalataratioof0.7,butatthat

temperature,thesystemhasanadditionalheatdemand.AttheoptimalO/Fratioandhenceoptimal

reformertemperature,theconversionrateisalsomaximized.Thisunisonpointofoperationdiffers

significantlyfromSMRandSMR+duetotheirbalancingofS/Cratiovs.temperature.Someexisting

plantsuseanair-blowndesign,whichresultinlowerCAPEX,butrequiresextensivedownstreamclean-

upifproducinghighpurityhydrogen.

Table17-POXparameterssensitivitytochangesinO/Fratio

Property Unit

O/FRatio: Mole/mole 0.500 0.600 0.650 0.656 0.700 0.750 0.800 0.900 1.000

Oxygenfeed: Sm3/h 50683 50830 52041 52323 55751 61451 67761 81811 98086

Product

Temperature:

°C 1022 1100 1173 1186 1320 1511 1698 2034 2300

Conversion

rate:

mole_H2/mole_NG 1.538 1.852 1.958 1.965 1.952 1.870 1.779 1.600 1.427

ReformingNG

flow:

Sm3/h 101366 84717 80063 79753 79644 81934 84701 90901 98086

Total

Reforming

flow:

Sm3/h 152049 135548 132105 132076 135396 143385 152462 172712 196172

CO2emission: Tonnes/day 1495 646 385 363 285 280 286 303 322

WaterInput

WGS:

kg/h 108567 106552 105382 105199 103409 100721 97771 91208 83607

Hydrogen

produced:

kg/day 500000 500000 500000 500000 500000 500000 500000 500000 500000

Plantenergy

efficiency:

- 0.619 0.740 0.782 0.784 0.784 0.761 0.734 0.681 0.629

Additional

Heat

Demand22:

GJ/h -859.9 -214.0 -16.2 0.0 54.7 50.1 36.2 4.0 -32.5

22AdditionalHeatDemand=TotalHeatDemand–TotalHeatAvailable

45

ThereformertemperatureissignificantlyhigherinPOXthaninSMRandduetotheabsenceofsteam,

sootformationisafamiliarphenomenon.Inexistingfacilities,thesootformationishandledwitha

scrubberafterthereformeroutlet[4].

Figure15-GraphshowinghowtheplantenergyefficiencyandCO2emissionsareaffectedbychangesintheoxygen-to-fuelratioinPOX.

Figure15showshowtheO/FratioaffectstheperformanceofthePOXsystem.Withlowoxygenrates,

theconversionofmethaneisincomplete,resultinginsignificantamountsofcarbonnotcapturedin

theabsorptioncolumn.ThisgiveshigherCO2emissions,sincethetailgasisfedtoafurnacetosupply

heat to theprocess.AthigherO/F ratios, theemissionsare low,due to full conversion.Theplant

energyefficiencystartstodropwhentheoxygenflowrate increasebeyond0.7duetotheenergy

consumption in the ASU and oxygen compression, as well as very high O/F ratios lead to total

combustion.

HYSYS is not capable of including soot formation in the simulation,which gives operation results

beyond realistic values. The inconclusiveness of the POX simulation was confirmed by Statoil

46

processingspecialistJosteinSogge23,explainingthatthesootformationwillreducetheefficiency.In

addition, he highlighted that the lack of catalyst will affect the results even further. The HYSYS

simulation assumes equilibrium, but the syngas product from POX will in practice not reach

equilibrium.Therefore,theresultsofthePOXsimulationsarenotconsideredconclusiveandPOXis

notevaluatedfurtherinthisthesis.

4.4.6 ATRResultsandDiscussion

CombiningSMRandPOX,ATRoperateswithbothoxygenandsteamfeedstreams.Optimizedwitha

minimalS/Cratioof1.5andanO/Fratioof0.616,theplantenergyefficiencyis0.82,withaconversion

rateof2.36.Table18showsthesimulationoverview,withthereformertemperatureat1020°C.

Table18-ATRSimulationOverview

NGFeed GHRFeed ATRNG

+Steam

Feed

ATRO2

Feed

WGS

Feed

CO2

Absorptio

nand

PSA1

Feed

PSA2

Feed

TailGas H2

Product

AirTo

Burner

FlueGas

Temperature[°C]: 50 400 560 250 320 25 25 25 25 350 1000

Pressure[Bar]: 50 25 24.5 24.5 23.25 22.25 22 2.5 20 1.2 1.2

Vapourfraction: 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0

Moleflow[kmole/h]: 3247 4221 9959 2000 16802 14387 1358 419 10334 907 1244

Massflow[kg/h]: 63816 81365 165006 64007 235283 191606 13287 11393 20833 26152 37546

Moleflow[kmole/h]:

CH4

H2

CO

CO2

H2O

C

C2H6

C3H8

i-Butane

n-Butane

i-Pentane

n-Pentane

n-Hexane

n-Heptane

n-Octane

N2

O2

2770.43

0.00

0.00

71.76

0.00

0.00

228.92

88.48

17.70

30.52

8.77

8.60

5.84

4.22

1.30

10.57

0.00

2770.43

0.00

0.00

71.76

974.13

0.00

228.92

88.48

17.70

30.52

8.77

8.60

5.84

4.22

1.30

10.57

0.00

3297.76

1083.39

424.96

194.42

4946.64

0.00

1.54

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

10.55

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

2000.21

53.34

7653.28

2843.10

1023.78

5218.28

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

10.55

0.00

53.34

10438.36

57.99

3802.53

24.31

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

10.55

0.00

53.34

1043.84

57.99

190.10

2.25

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

10.55

0.00

53.34

104.38

57.99

190.10

2.25

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

10.55

0.00

0.00

10333.97

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

716.11

190.36

0.00

0.00

0.00

301.44

213.31

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

726.66

2.49

23Specialistinmid-anddownstreamprocessing,Statoil.

47

ATR operation requires control of both oxygen and steam supply in order to maintain optimal

operation.Table19showsthesystemsresponsetochangesinoxygeninput,andhencethePOXpart

ofthereformingreactions.AhigherO/Fratioresultsinhighertemperatures,duetomoreexothermic

reactions.TheplantenergyefficiencyhasamaximumvalueatanO/Fratioof0.616.

Table19-ATRparameterssensitivitytochangesinO/Fratio

Property Unit


S/CRatio: Mole/mole 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5

Oxygenfeed: Sm3/h 39701 42143 46171 47294 50263 55556 61397 67681 81655

ProductTemperature: °C 830 889 993 1020 1087 1199 1313 1424 1635

Conversionrate: mole_H2/

mole_NG

1.954 2.232 2.366 2.357 2.307 2.201 2.091 1.986 1.788

ReformingNGflow: Sm3/h 99251 84287 76952 76776 77328 79366 81863 84601 90728

TotalReformingflow: Sm3/h 138952 126430 123123 124070 127591 134922 143260 152282 172383


WaterInputWGS: kg/h 0 0 6642 6271 4068 0 0 0 0

Hydrogenproduced: kg/day 500000 500000 500000 500000 500000 500000 500000 500000 500000

Plantenergy

efficiency:

- 0.635 0.746 0.815 0.816 0.809 0.787 0.761 0.735 0.683

AdditionalHeat

Demand24:

GJ/h -867.9 -306.0 -32.4 -26.7 -50.1 -131.5 -230.3 -338.7 -581.5

WhenitcomestoCO2emissions,keepingtheoxygensupplyatoptimalconditionsisimportant.Adrop

inO/Fratioto0.5morethandoublestheCO2emissions.Thereasonfortheincreasedemissionsisthe

unconvertedmethaneslip.Methane,whichpassesthroughthereactor,willnotbeaffectedinWGS

reactors,neitherwill itbecapturedinthecarbonabsorptioncolumn.Hence, lowerO/Fratioleads

directlytomoreemissions.Ontheotherhand,anincreasedO/Fratioleadstototalcombustionand

moreCO2production. TheproducedCO2will be capturedanddoesnot affect the total emissions

significantly.


48

ChangingtheS/CratiohasasimilareffectinATRasinSMR.Moresteamgivesahigherconversion

rate,butdemandsmoreheatinordertooperate.InATR,thisleadstolowerreformertemperature,

becausetheheatsupplyisfixedfromthePOXsectionofthereactor.AscanbeseenfromTable20,

reducing theS/C ratiogiveshigherefficiency,even though theconversion ratedrops. Ideally,ATR

wouldoperatewithlowS/Cratios,butduetosootandcarbonformation,1.5isthelowerlimit.Hence,

aS/Crationof1.5ischosenastheoptimalpointofoperation.

Table20-ATRparameterssensitivitytochangesinS/Cratio

Property Unit

O/FRatio: Mole/mole 0.616 0.616 0.616 0.616 0.616 0.616 0.616

S/CRatio: Mole/mole 0.1 0.5 1.0 1.5 2.0 2.5 3.0

Oxygenfeed: Sm3/h 46662 46752 46979 47294 47584 47964 48406

ProductTemperature: °C 1251 1160 1080 1020 973 934 902



TotalReformingflow: Sm3/h 122411 122648 123244 124070 124831 125827 126987


WaterInputWGS: kg/h 90354 66338 36555 6271 0 0 0


PlantEnergyEfficiency: - 0.828 0.826 0.822 0.816 0.811 0.805 0.797

AdditionalHeatDemand25: GJ/h 12.6 7.0 -7.1 -26.7 -43.2 -66.2 -93.5

The operating temperature is found to correlatewellwith literature, describing ranges from900-

1150°C[4].ATRiscommonlyusedinchemicalindustry,especiallyinmethanolproduction,duetoits

favourableH2/COratioofaround2.Thisalsofitswellwiththeresultsinthisthesis.Ontheotherhand,

somedeviationmaybeassumedontheenergyefficiency.AmajorityofreportsdescribesSMRasthe

mostenergyefficientmethodofhydrogenproductionfromnaturalgas.Here,ATRprovesequal.One

explanationisthat,similaraspurePOX,thepartialoxidationissimulatedtoowellinHYSYS.Carbon

and soot formationwill slow the reaction rates as the catalyst degenerates, but that effect is not

includedintheHYSYSsimulations.ThiseffectisnotassevereinATRasinPOXduetothesteamfeed

tothereactor.


49

ThechangesinplantenergyefficiencyandCO2emissionsduetotemperaturevariationsfollowinATR

asimilarcurveasinPOX,displayedinFigure16.TheoptimalO/FratioisalittlelowerinATRthanPOX,

butthelevelofenergyefficiencyishigher.Inaddition,theCO2emissionsinATRarelower,duetothe

enhancedconversionintheSMRsectionofthereactor,aswellasahigherS/CratiothroughtheWGS,

providingabettershifttoCO2.Asinallthereformersystems,themorecarbonboundinCO2afterthe

WGS,thehigherthecapturerateandthus,loweremissions.

Figure16-GraphshowinghowtheplantenergyefficiencyandCO2emissionsareaffectedbychangesinO/FrationinATR.

4.4.7 CREResultsandDiscussion

CombinedATRandelectrolysiswilloperateasthetraditionalATR,butwithalowerproductionrate

fromnaturalgasandadifferentASU.

Table21-CREsystemoverview

NG

Feed

GHR

Feed

ATRNG+

Steam

Feed

ATRO2

Feed

WGS

Feed

CO2Absorption

andPSA1Feed

PSA2

Feed

Tail

Gas

H2From

ATR

H2From

EL

AirTo

Burner

Flue

Gas

Temperature

[°C]:

50 400 560 250 320 25 25 25 25 80 350 1000

Pressure[Bar]: 50 25.25 24.75 24.75 23.50 22.5 22.25 2.5 20.25 20.25 1.2 1.2

Vapour

fraction:

1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0

50

Moleflow

[kmole/h]:

2353 3059 7215 1428 12156 10414 996 316 7478 2856 787 1044

Massflow

[kg/h]:

46240 58956 119577 45700 169943 138442 9806 8436 15075 5758 22712 31148

Moleflow

[kmole/h]:

CH4

H2

CO

CO2

H2O

C

C2H6

C3H8

i-Butane

n-Butane

i-Pentane

n-Pentane

n-Hexane

n-Heptane

n-Octane

N2

O2

2007.39

0.00

0.00

52.00

0.00

0.00

165.87

64.11

12.82

22.12

6.35

6.23

4.24

3.06

0.94

7.65

0.00

2007.39

0.00

0.00

52.00

705.83

0.00

165.87

64.11

12.82

22.12

6.35

6.23

4.24

3.06

0.94

7.65

0.00

2390.68

781.78

306.34

141.25

3586.02

0.00

1.12

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

7.65

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

1428.14

51.80

5558.10

2037.11

751.61

3749.81

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

7.65

0.00

51.80

7553.22

41.96

2742.13

17.43

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

7.65

0.00

51.80

755.32

41.96

137.09

1.63

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

7.65

0.00

51.80

75.53

41.96

137.09

1.63

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

7.65

0.00

0.00

7477.69

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

2856.28

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

621.92

165.32

0.00

0.00

0.00

230.85

180.77

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

629.57

2.97

ThehydrogenproductionfromATRwillbereducedbyaround30%,butthatwillnotaffecttheprocess

simulations fromHYSYS. The only thing that deviates is the optimization. Due to the high energy

consumptionoftheelectrolysers,theoptimalO/FratiowillbelowerthaninATRinordertogetthe

bestplantenergyefficiency.ThatmeansalessefficientATRprocess,butabetteroverallresult.This

canbeseenfromtheresultsinTable22,andishighlightedinFigure17.Noticehowfasttheefficiency

dropswith increasedO/Fratioduetothepowerconsumptionof theelectrolysis.WithhigherO/F

ratio,therateofwhichELproduceshydrogenincreasesandthustheemissionscontinuetodrop.The

highemissionsatlowO/Fratiosoriginatesfromthemethaneslipduetolowconversion,similarasin

POXandATR.

Table22-CREparameterssensitivitytovariationsintheO/Fratio,givenoptimalS/Cratio.

Properties Unit


S/CRatio: Mole/mole 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5

Oxygenfeed: Sm3/h 30000 31365 33524 33768 35616 38191 40862 43553 48943

ProductTemperature: °C 831 890 993 1004 1087 1199 1312 1424 1635

Conversionrate: mole_H2/mole_NG 1.950 2.229 2.365 2.362 2.307 2.201 2.092 1.986 1.788

ReformingNGflow: Sm3/h 75001 62730 55873 55630 54794 54558 54483 54441 54381

TotalReformingflow: Sm3/h 105001 94095 89396 89398 90411 92749 95345 97994 103324


WaterInputWGS: kg/h 0 0 4747 4666 2850 0 0 0 0

TotalELconsumption: kWh/kg_H₂ 58 58 57 57 58 58 58 58 58

Hydrogenproduced: kg/day 500000 500000 500000 500000 500000 500000 500000 500000 500000

ATRBasedH₂: 377220 371635 362801 361801 354233 343700 332765 321753 299694

51

ELBasedH₂: 122780 128365 137200 138199 145765 156300 167233 178247 200306

PlantEnergyEfficiency: - 0.627 0.704 0.745 0.745 0.738 0.721 0.702 0.684 0.651

AdditionalHeatDemand: GJ/h -659.7 -230.8 -25.1 -22.0 -36.1 -90.6 -153.4 -218.1 -348.8

Figure17-GraphsshowinghowtheplantenergyefficiencyandCO2emissionsareaffectedbychangesintheO/Fratio

ThebehaviourofCREwhenchangingtheS/CratioisidenticaltoATR,butwithsmallerresponsedue

tothesplitproduction.Table23showstheresultsofthesensitivityanalysisofCREwithchangesin

S/Cratio.

Table23-CREparameterssensitivitytovariationsinS/Cratio

Properties Unit

O/FRatio: Mole/mole 0.607 0.607 0.607 0.607 0.607 0.607 0.607

S/CRatio: Mole/mole 0.1 0.5 1.0 1.5 2.0 2.5 3.0

Oxygenfeed: Sm3/h 33363 33421 33570 33768 33949 34172 34423

ProductTemperature: °C 1221 1136 1060 1004 960 923 892



TotalReformingflow: Sm3/h 88327 88480 88876 89398 89878 90469 91133


WaterInputWGS: kg/h 65658 48508 26766 4666 0 0 0

TotalELconsumption: kWh/kg_H₂ 57 57 57 57 57 57 57


52

ATRBasedH₂: 363458 363222 362609 361801 361058 360145 359120

ELBasedH₂: 136542 136779 137391 138199 138941 139855 140880

PlantEnergyEfficiency: - 0.754 0.753 0.750 0.745 0.741 0.736 0.731

AdditionalHeatDemand: GJ/h 13.2 8.2 -4.8 -22.0 -36.6 -55.6 -77.3

53

5 FinancialAnalysisofLarge-scaleHydrogenProduction

Inorder to evaluate the systemsdefined inChapter 4 to assist a potential investmentdecision, a

financialanalysisisnecessary.Improvedthermodynamicefficiencyandoperationisoftenrelatedto

increased investment cost and higher operation expenditures. There are few journals or reports

comparing the cost of various hydrogen productionmethods to this level. Therefore, a variety of

different sourceshasprovided the informationneeded to compose thisoverview.Theaimof this

chapteristoestablishabenchmarkproductioncostofcarbon-leanhydrogen.Byperformingacost

analysis,theCAPEXandOPEXofeachsystemwillbedecomposedinordertohighlightdifferencesin

how the individual designs affect the overall viability. A sensitivity analysiswill highlight how the

individualsystemsareaffectedbyvariationsinfeedstockcost,financialmarketsituationsandfacility

design.Finally,thechapterwillconcludewithadiscussionofwhichsystemisbestsuitedforlarge-

scaleoperationinNorway.AllfinancialandtechnicalinputsusedinthisanalysisarelistedinAppendix

A.

Due to the technical analysis and limited information on investment cost and operational

expenditures,POXisnotincludedinthefinancialanalysis.

5.1 FinancialRisk

Ifalarge-scaleproductionplantistobebuilt,thebusinesscasecarriesconsiderablerisk,seenfroma

2016perspective.Significantuncertaintiesarerelatedtothemarketdevelopmentofinfrastructure

and political incentives for a greener transportation sector and CO2 emission reductions in the

industry.Becauseofadiversemarket,withopportunitieswithintransportationandindustry,therisk

ofsubstitutetechnologysuchasimprovedbatteriesorbiofuel,isreduced.Economiesofscalerelated

tothefuelcellindustryisimportantinorderforthatmarketsegmenttoreachadequatelevels.The

natural gas reforming technology itself ismature,with several facilitiesexisting today. Theoverall

performance risk could be greatly reduced by running a small-scale demo project prior to the

investmentdecision.

5.1.1 DiscountRate

Theprojectdiscountratehasbeensetto10%fortheinvestmentscenariosinthisthesis.Thediscount

rate is both describing the time value of money and the risk premium attached to this specific

investment. The risk free returnon capital is estimatedby theaverage long-term interest rateon

Norwegiangovernmentbondsof1.57%in2015[32].Thecostofcapitalofgreenenergyprojectsin

Europewasapproximately6%in2015[33,17].Thisimpliesariskpremiumofaround4.5%.Because

54

ofalarge-scalehydrogenexportprojecttoanuncertainmarketholdssignificantlyhigherrisk,therisk

premiumisclosetodoubled,resultinginadiscountrateof10%.Tofurtherjustifytherate,feed-in-

tariffsorothersubsidiesarenot includedintherevenuestream,eventhoughit isvery likelyfora

projectsimilartothatdescribedinthisthesistoreceivesubstantialsupport.Especiallyconsideringthe

combinationofCO2emissionreductionsandtechnologydevelopment.

As a comment, the discount rate chosen for this analysis does not necessarily reflect the actual

requireddiscountratepriortotheinvestmentdecisionatalaterstage.

5.2 WhatIsthePriceTargetofCarbon-leanHydrogenProducedinNorway?

AsthisthesisaimtoprovideabenchmarkforthecostofproducinghydrogeninNorway,animportant

question arises: At what level must the breakeven price of hydrogen be in order to be cost

competitive?

Duringtheprojectworkdoneinthefallof2015,acompetitiveanalysisontheproductionofhydrogen

inGermanyandUKwasconductedinordertoprovideatargetfortheproductionandexportcost.It

wasestimatedthatthecostsofliquefaction,storageandtransportationwouldbeintherangefrom

0.9€/kgH2ofhydrogenproducedto1.9€/kgH2in2030[20].Themarketanalysisdoneinthesame

studyconcludedthatamarginalcosttomarketofbetween2-4€/kgH2iswhatcanbeexpectedof

domestic production of hydrogen in UK and Germany, including traditional hydrogen production

withoutCCS[20].Hence,basedontheconservativeliquefaction,storageandtransportationcosts,a

productionpricebelow2.1€/kgH2isnecessaryinordertobecompetitiveinalarge-scaleEuropean

exportscenario.Onecanseefromtheestimations,thatinascenariowheredomesticproductionin

UKorGermanyis2€/kgH2andtransportationcostsarehigh,exporttothosemarketswillnotbea

viablebusinesscase.

TheJapanesegovernmenthasreleasedanimporttargetpriceofimportedhydrogenof30yen/Nm3

whichequals2.7€/kgH226[22].IfexportedtoJapan,thetransportcostwillincreasebysomefactor,

but this only accounts for a small part of the total cost.Hence, given a conservative liquefaction,

storageandtransportationcost,export to Japandoesnotseemviable in the future.Ontheother

261€=123.7Yen,Exchangerateof30.05.2016

55

hand, if costcompressionallows foroptimisticdistributioncosts, thecaseholdspotential,givena

productioncostbelow1.8€/kgH2.Theseareearlyanduncertainvalues,butprovideaballparktarget.

5.3 CostAnalysis

Thecostanalysis isbasedondatacollected fromvariousproject reportsand journals, referred to

throughoutthechapter.Althoughsignificantuncertaintyisrelatedtotheexactvalueslistedinthis

section, the relativedifferenceof thecosts shouldprovidekey insights toan investmentdecision.

Included in thecostanalysis is theentireproduction facility, fromdesulfurizednaturalgasfeedto

hydrogenoutputat20barand25degreesCelsius.CAPEXandOPEXoftheCCSplantisalsoincluded,

although the process itself is excluded in the process model. The assumptions behind the most

important cost drivers are explained in sections 5.3.5 through 5.3.7. In addition, a detailed list of

assumptionswithreferencesisfoundinAppendixA.

First,anoverviewoftheexpendituresispresentedinTable24andTable25,respectively.Further,the

CAPEX and OPEX of the individual systems are explained in more detail, providing a deeper

understandingofthedifferences.

Table24-CAPEXoverviewofthehydrogenproductionsystems.Allsystemsaredesignedwithadailyproductioncapacityof500tonnesofH2,deliveredat20bar.

CAPEXOVERVIEW-500tonnesH2perday HydrogenProduction Prefix SMR SMR+ ATR Electrolysis CREHydrogenProductionplant: M€ 349.0 423.9 296.2 429.3 358.1Cellstackreinvestment: M€ - - - 51.9 16.3AirSeparationUnit: M€ - - 64.3 - -Compressors: M€ 0.2 0.2 0.7 - -Landarea: M€ 5.4 5.4 5.4 5.4 5.4

Auxiliarycomponents:%ofinvestment 20% 20% 20% M€ 69.8 84.8 72.2 44.6

InstallationandEngineering:%oftotalinvestment 20% 20% 20% 20% 20%M€ 83.8 101.8 86.7 96.2 80.5

TotalCAPEXH2Production: M€ 508.2 616.2 525.6 582.8 505.0 CarbonCaptureandStorage Prefix SMR SMR+ ATR Electrolysis CRECarboncapturefacility: M€ 117.4 139.9 137.5 109.4Carbontransportandinjection: M€ 176.2 209.9 206.2 164.0Drillingandinjectionwell: M€ 88.1 104.9 103.1 82.0TotalCCSCAPEX: M€ 381.7 454.8 446.8 - 355.4 TotalSystemCAPEX: M€ 889.9 1071.0 972.4 582.8 860.4

56

Table25-OPEXoverviewofthehydrogenproductionsystems.Allsystemsaredesignedwithadailyproductioncapacityof500tonnesofH2,deliveredat20bar

OPEXOVERVIEW-500tonnesH2perday HydrogenProduction Prefix SMR SMR+ ATR Electrolysis CRESpecificcostofelectricity: €/kgH2 0.002 0.002 0.026 1.081 0.324Costofelectricity: M€/year 0.3 0.4 4.5 187.5 56.1H2Prodgridconnectioncost: M€/year 0.1 0.1 0.7 24.3 8.5Costofnaturalgas: M€/year 114.1 119.9 111.1 - 80.5CO2tax: M€/year 3.2 1.5 0.9 0.7SystemOPEXrate: %ofCAPEX/Year 5% 5% 5% 5% 5%SystemOPEX: M€/year 25.4 30.8 26.3 29.1 25.3TotalOPEXH2Production: M€/year 143.1 152.6 143.5 240.9 171.1 Carboncaptureandstorage Prefix SMR SMR+ ATR Electrolysis CRECCScostofelectricity: M€/year 2.12 2.72 2.65 1.91CCSgridconnectioncost: M€/year 0.32 0.41 0.40 0.29

CCSSystemOPEX:%ofCAPEX/Year 5% 5% 5% 5%M€/year 19.1 22.7 22.3 17.8

TotalOPEXCCS: M€/year 21.5 25.9 25.4 - 20.0 TotalSystemOPEX: M€/year 164.6 178.5 168.9 240.9 191.0

57

5.3.1 CostBreakdownSMR

AsseenfromTable24,thetotalinvestmentcostofthebasicsteammethanereforming(SMR)system

isM€889.9.Thisislowcomparedtotheothernaturalgasreformingsystems.OPEXisdominatedby

the cost of natural gas, due to the minimal electricity consumption. The dedicated hydrogen

productioncomponentsdominatetheCAPEX,whilethenaturalgasconsumptionaccountforalmost

75percentofOPEX.

Figure18-CAPEXBreakdownoftheSMRsystem.Thethreelightgreyvaluesarerelatedtohydrogenproduction.ThethreedarkgreyvaluesarerelatedtoCCS

Figure19-OPEXbreakdownoftheSMRsystem.Thecostofnaturalgasdominatewithcloseto65%oftheexpenditures

58

5.3.2 CostBreakdownSMR+

Inorder to further reduceemissions, SMR+usehydrogen insteadofnatural gas in the furnace to

provideheatforthereformer,asmentionedinSection4.3.3.Thisaffectsthecostsignificantly.The

hydrogendemand impliesahigher yield,hencemorenatural gas through the reformer. Since the

reformerinvestmentcostisbasedonhydrogenoutput,thisislargelyaffectedbythisdesignchange.

Thenaturalgasconsumptiononlyslightlyincreases.ThecostpictureasawholeissimilartoSMR.

Figure20-CAPEXBreakdownoftheSMR+system.NoticethesignificantincreaseinH2productionplantinvestmentcost.Thisisduetotheincreasednaturalgasprocessinputandhencealargerreactor.

Figure 21 -OPEXBreakdownof the SMR+ system. Thenatural gas cost dominateas in SMR. Thegeneral cost level hasincreasedevenly.

59

5.3.3 CostBreakdownATR

ThecostbreakdownofATRdiffersfromSMRandSMR+mainlyduetothedifferentreformerdesign

andtheneedforanairseparationunit(ASU).TheASUrepresentsasignificantcapitalinvestmentand

consumesafairamountofpower,affectingtheoperatingexpendituresaswell.Ontheotherhand,

theATRreformerhasasimplerdesign,reducingtheinvestmentcostofthereactoritself.OPEXisstill

dominatedbynaturalgascost.

Figure22-CAPEXBreakdownoftheATRsystem.DiffersfromSMRmainlyonthelessexpensivereformerandtheinclusionofanairseparationunit.

Figure23-OPEXBreakdownoftheATRsystem.Thenaturalgasdominateamongtheexpenditures,buthere,costofelectricityimpactstoalargerextent.

60

5.3.4 CostBreakdownCRE

Althoughvisuallydifferentfromthetraditionalreforming,thecombinationsystemisverysimilarto

ATR incapitalexpenses. Insteadofa largereformerandanairseparationunit,CREusesasmaller

reformerandelectrolysistoproducehydrogen.ThisdistributesthehydrogenproductionCAPEXon

ATRplantandelectrolysisplant.ThesameeffectonOPEX,asthelargenaturalgaspieceissplitinto

electricitycostandnaturalgascost.CREhasalowerCAPEXcomparedwithpurereforming,butOPEX

isincreasedduetolowerplantenergyefficiency.

Figure24-CAPEXbreakdownofthecombinedreformingandelectrolysissystem.

Figure25-OPEXbreakdownofthecombinedreformingandelectrolysissystem.Here,thecostofnaturalgasandelectricityareclosetoequal

61

5.3.5 EnergyInputCosts

OPEXofalltheproductionsystemsisdominatedbyenergyinputexpenditures,wherethemaindrivers

arethecostsofnaturalgasorelectricity.Bothvariablesarehighlyvolatileandthusdifficulttopredict,

which results in uncertainty. The cost of natural gas is set to 0.174 €/Sm3, based on the average

internalgaspriceofStatoilin2015[34].Theinternalgaspricereflectsamarketpricewheremarketing

anddistributioncostsarededucted.TheelectricitypriceinNorwayissettobe20.03€/MWh.Thisis

basedonthemonthlyaveragesofNASDAQcommodityENOYR17,18and19fromApriltoMayof

201627[35].Anytaxationonpowerconsumptionisnot includedinthisthesis.Thegridconnection

costissettobe230NOK/kWinstalledcapacity,basedontheNorwegiannationalgridtariffof2016

[36].

5.3.6 ProductionFacilityCosts

CAPEXoftheSMRsystemsarebasedonEuropeanaveragesoflarge-scalesteammethanereformers

of400€/kWcapacity,Higherheatingvalue(HHV)ofhydrogenoutput,ina300MWfacility[1].Further,

SMRisscaledbasedonhydrogenoutputwithacoefficientof0.828,assumingnormaloperation.The

formulausedinscalingcapitalexpendituresisexplainedinAppendixA.Thereasonfortherelatively

poorscalingisduetothemodularreactordesign.SMR+isfurtherscaledfromSMRtoaccountforthe

increaseinprocessNGfeed.ForATR,theCAPEXisbasedonacostanalysisreportongas-toliquid

systemsdonebytheU.S.departmentofenergyin2013[37].Duetoasimpleandlessmodularized

design,theATRreactorcostcanbescaledwithafactorof0.728.ThecostbasisofSMRisthesystem

totalinvestment,whileATRisgivenwitheachcomponent,hencethemoredetailedcostbreakdown.

Similar forall thereactorcostestimations is thattheeffectofchangingwater input isnotdirectly

includedintheresults.Thecomponentsareeitherscaledbasedonhydrogenoutputornaturalgas

input.The reason for this is the limited informationof theactual S/C ratiosused in the reference

systems.Byaddingthiseffect,amoreoptimaldesigncouldhavebeenfound.Sincethisissimilarfor

allthesystems,itwouldnothavealargeeffectontherelativecostestimations.

27TheestimationofelectricitypricewasdonebasedonarecommendationbyProfessorMagnusKorpås,NTNU.28ThescalingcoefficientshavebeenestimatedincooperationwithJosteinSogge,Statoil

62

ThecostoftheelectrolysisplantisbasedontheavailabledatafromNEL-Hydrogen,600€/kWinstalled

capacityofa50MWplantproducing26tonnesperdayat15bar[38].Becauseofstrictmodularity,

theelectrolysisplantisscaledbyafactorof0.9.

Similarforallreformingsystemsisanadditional20percentaddedtocoverauxiliarycomponentse.g.

watersystems,heatintegrationandpowersystem.Thisisnotincludedintheelectrolysersystem,due

to the overall cost used in the thesis is listed as a total plant investment cost. Installation and

engineering costs account for an additional 20% of system CAPEX. OPEX related to the hydrogen

productionotherthanNGandelectricityisastandard5%ofCAPEX.

5.3.7 CarbonCaptureandStorageCosts

CCSisaprerequisiteforthesuccessoffossil-basedhydrogenproduction.Thetechnologyisusedin

the Norwegian oil and gas sector already, storing extracted CO2 from reservoir gas. The cost

estimations are based on approximate investment costs of the CCS system at Hammerfest LNG,

providedbyProfessor II and Statoil researcher JosteinPettersen.At the gas field “Snøhvit” in the

BarentsSeaaround700000tonnesofCO2 iscapturedandsequestratedannually.TheCCS-system

consists of a separating unit followed by a compression stage. CO2 is then transferred through a

pipelinetoasubseainjectionunit.Allthecomponentsareincludedinthecostanalysis,includingthe

investmentinthedrillingofaninjectionwell.Theprofessorestimatedthetotalinvestmentcosttobe

2600M€forthereferencecase,withOPEXequalling5%ofthetotalinvestment,annually.Thecost

isscaledtothedifferentCO2withacoefficientof0.7,alsoprovidedbytheprofessor.

Theaveragecarbonemissionpriceof2016is69.98NOK/tonneCO2,wherefurtherspecificemission

tax is excludeddue to theoverall emission reductiona facilityof this scale represents [39]. Some

expectthatamoreintensivetaxationofcarbonemissionswillbeintroducedinthefuture,inorderto

meet emission reduction targets. How the different systemswill respond to that, is presented in

Section5.7.3.

5.4 BreakevenPriceofHydrogen

Inordertodeterminethemostcost-efficienthydrogenproductionmethod,thebreakevenprice is

estimatedforeachsystem.Thebreakevenpriceisalsoknownasthelevelizedcostofhydrogenand

definedinthefollowingway:

63

FGHIJHKHLMGNOH = PQ9RSHTUHLVNWQGHXRKHGYNSHWN9H

PQ9RSℎ[VGR\HLUGRVQOHVRKHGYNSHWN9H=

]^M_`? + aM_`?(1 + G)?

=?ef

52?1 + G ?

=?ef

In a given cost scenario, the sales price of hydrogen for which the net present value is zero, is

equivalenttothebreakevenprice.AselaboratedinSection5.1.1,thediscountrateforthisprojectis

settobe10%.Thelifetimeoftheprojectissetto25yearsandthereliabilityoftheproductionisset

to95%,equalto347daysoffullproduction,annually.Inaddition,allCAPEXareassumedpaidinthe

firstyearofoperation.

Figure26showsthebreakevenpriceofthedifferenthydrogenproductionsystems,basedonthecost

data presented in Section 5.3. The sensitivity analysis in Section 5.7 will provide estimations on

optimisticandconservativescenariosaswell,creatingarangewithinwhichthebreakevenpriceof

hydrogenshouldbe,giventheassumptionsofthisthesis.

Figure26-Blockdiagramshowingthebreakevenpriceofcarbon-leanhydrogen.Includesallauxiliarycomponents,includingCCS.500tonnesofH2daily,deliveredat20bar.TheblueandgreencoloursindicatetheshareofwhichOPEXandCAPEXcontributethroughoutthelifetime,respectively.10%discountrateand25yearslifetime.

It is interesting that the difference in breakeven price is so small, across the various production

methods.SMRappearstobethemostcost-efficientsystem,withabreakevenpriceof1.51€/kgH2,

butalltheothersystemsareincludedwithina17%priceincrease.ATRissecond,atapriceof1.59

€/kgH2,althoughprovidingaconsiderablereductionofCO2emissionscomparedtoSMR.

64

Figure 27 - Block diagram showing the breakeven price of carbon-lean hydrogen, highlighting the additional cost CCSrepresentsinthedifferentsystems.KeepinmindtheamountofCO2capturesisdifferentforeachsystem.

Looking at thebreakevenpriceof production, it is interesting to highlight theprice premiumCCS

represents ineachsystem.AsshowninFigure27,CCSrepresentsapproximately20percentofthe

totalcost.Section5.2estimatesacompetitiveproductioncosttobebelow2.1€/kgH2,inaEuropean

exportscenario.Astheresultsofthisanalysisshow,all thesystemsprovidecarbon-leanhydrogen

withabreakevenpriceunder2.1€/kgH2.Whethertheindustrywillaccepta20percentincreasein

costtoproducecarbon-leanhydrogen,comparedtotraditionalhydrogen,ishardtopredict,andmay

beaffectedbyseveralfactorslikefeed-in-tariffsandavailablesubsidies.

As these results show, theestimationsof thebreakevenpriceof carbon-leanhydrogen inNorway

rangesfrom1.51–1.76€/kgH2.Furtherinthischapter,theseresultswillbecomparedtootherrecent

studiesandanoptimisticandconservativescenarioisdefinedinordertoprovidecostrangesforeach

productionsystem.

5.5 CostComparisonwithH2AReportbyNationalRenewableEnergyLaboratory

Validating results fromanalyses like theonesperformed in this thesis canbedifficult, due to the

variationinsourceliteratureanduncertaintyinestimations.Oneeffectivewayoftestingtherealism

intheresultsistocomparethemwithexistingjournals.Throughoutthetechnicalanalysis,thisisdone

inordertoensurerealisticprocessoperation.Thissectionwillpresentthehighlightsfromaproject

carriedoutbytheNationalRenewableEnergyLaboratory (NREL) in theU.S.calledH2A(Hydrogen

65

analysisproject),acomprehensivetechno-economicanalysisofhydrogenproductionfrom2009[31].

Figure28presentstheresultsoftheH2Aproject,withvaluesgivenin2005$.Forsimplicity,theNREL

reportisreferredtoastheH2Areportandthecurrentmasterthesisisreferredtoas“thisthesis”.

Figure28-ResultsoftheH2Aanalysisofhydrogenproductionmethods.TheFutureestimationsarebasedon2025projections[31].Keepinmindthatthevaluesaredisplayedin2005$.Theconversionfactorto2016$is1.225[40].

The first apparent information from Figure 28 is that hydrogen production from a hydrocarbon

feedstockissignificantlymorecost-efficientthanelectrolysis.Eventhoughthisislikelytobethecase,

astheresultsoftheanalysisinthisthesisalsoindicates,thelargedifferencecanalsobeexplainedby

scaleofproductionandfeedstockcost.Thisisalsothemainreasonforthesignificantcostreduction

inthefuturescenario,combinedwithahigherenergyefficiency.Anotherinterestingdetail,although

notcoveredinthisthesis,isthecompetitivenessofhydrogenproducedfrombiomass.

66

Table26-CostcomparisonofthisthesiswiththeresultsofH2A.Here,thebreakevenpriceofhydrogenfromH2Aisconvertedfrom2005$to2016€,basedonthestandardcurrencyexchangerateusedaswellasaUSinflationcalculator[40],[31].

SMRwithoutCCS SMRwithCCS Electrolysis

H2A

Report

ThisThesis H2A

Report

This

Thesis

H2A

Report

This

Thesis29

Breakevenpriceof

hydrogen:

€1.48 €1.19 €1.81 €1.51 €4.27 €1.94

OPEXpercentageof

hydrogencost:

83.5% 73.1% 75.5% 62.9% 79.5% 74.7%

Table26showsacomparisonbetweentheanalysisofSMRandelectrolysiscarriedoutinH2Areport

andtheresultsfromthisthesis,giveninSection5.4.SMRwithoutCCSisalsoincluded, inorderto

displaythecost-premiumitrepresents.

As can be seen from the table, the H2A report presentsmore expensive estimates. For SMR the

differencecanbeexplainedbytwofactors:First,thedesignoutputofSMRinH2Ais341tonnesof

hydrogenperday,comparedto500usedinthisthesis.Theupscalingwillresultinfurtherreduction

ofCAPEXperhydrogenproduced.Second,theaveragenaturalgaspriceusedbyNRELis0.25€/Nm3

(convertedto2016€)whichisalmost50%morethanthe0.17€/Nm3internalgaspricefromStatoil

usedinthisthesis.ThisalsoexplainsthehigherOPEXpercentageofthebreakevenpricefortheH2A

results.IfthenaturalgaspriceisadjustedtothevalueinH2A,thebreakevenpriceofSMRwithCCS

increaseto1.80€/kg,withanOPEXsplitof68.9%,whichishighlycomparable.

Ontheelectrolysissystem,thedeviationoftheresultsislarge,butithasasimpleexplanation:the

costofelectricity.TheelectricitypriceusedinH2Ais60.6€/MWh,morethanthreetimesthe20.03

€/MWhusedinthisthesis.WithanOPEXpercentageof75-80%,thecheapandavailablehydropower

inNorwaydirectlycausesthepriceofhydrogentobelessthanhalfofwhatsimilartechnologycan

provideintheUS.Thatresultisveryinteresting.BecauseNRELused51tonnesperdaycapacityon

theelectrolysis system, thevalue from this thesis is alsoadjusted to thatproductionvolume.The

changeinproductioncapacityincreasethebreakevenprice,duetoscaleeffects,from€1.76perkgto

29Theproductioncapacityischangedfrom500tonnesperdayto51,inordertomorecomparable.

67

€1.94.If60.6€/MWhisusedinthisthesis,thebreakevenpriceofhydrogenfromelectrolysisis4.13

€/kg,only3percentlessthanH2A.

ThissectionshowsthatthecostestimationsofSMRandelectrolysisarecomparabletosimilarstudies

carried out in the past, improving the viability of the results. A very interesting discovery is the

immenseeffectthelow-cost,Norwegianenergyresourceshaveontheproductioncostofhydrogen.

5.6 EnvironmentalImpact

Producing hydrogen brings socio-economic benefits, which create an added value not taken into

accountinthecostanalysis.TheNorwegianhydrogenproductionpresentedinthisthesis,canreduce

global CO₂ emissions, contribute to technology development and create jobs. In the cost analysis

Section5.3,thevalueoflarge-scalehydrogenproductionwasassessedfromabusinessperspective

whilethevalueofavoidedCO₂emissionsarenotfullytakenintoaccount.Thischapterwilldiscussthe

value of reduced carbon emissions andwhether the project has sufficient positive impact on the

environmenttooutweighthecostofCCS.

5.6.1 CO₂Emissions

Mostof thehydrogenproduction today isbasedonconversionof fossil resourceswithoutcarbon

capture and storage (CCS) [1]. All the CO₂ produced is therefore vented out in the atmosphere

contributing to globalwarming. InDecember 12th 2015more than 200 countries signed the Paris

climateagreementandhavecommittedtostartthetransitiontowardsalow-emissionsociety.The

solutionpresented in this thesiscancontributetoachievetheemissiontargetas itcost-efficiently

produces CO₂-lean hydrogen. Governments need concrete, large-scale projects in order to meet

targets,andasTable27shows,eventheproductionmethodwiththehighestCO2emissionsstudied

inthisthesiscancutglobalemissionsby2.98milliontonnesperyear.Theunavoidableemissionsfrom

theSMRplantaddsup to23.9gramsofCO2perkm inaToyotaMirai,assuming100kmperkgof

hydrogen30.Incomparison,thenewvehicleemissiontargetofEUin2021is95g/km,andanextremely

low-emittingvehicleisdefinedasbelow50g/km[41].

30Someemissionsmaybecausedbydistribution,butastheprojectworkof2015showed,notalargeaddition.

68

Table27-AnnuallyCO₂CapturedandAvoided

Value UnitCO₂CapturedSMR: 1.06 Milliontonnes/yearCO₂CapturedSMR+: 1.45 Milliontonnes/yearCO₂CapturedATR: 1.36 Milliontonnes/yearCO₂CapturedCRE: 0.95 Milliontonnes/yearCO₂Avoided31SMR: 2.98 Milliontonnes/yearAnnualemissionofCO₂equivalentsinNorway:

53.8 Milliontonnes/year[24]

Table28showstheCO₂emissionsperkWhproducedelectricityfromalargegasturbine,withand

withoutacombinedcycle,andfromaprotonexchangemembranefuelcell(PEMFC)usinghydrogen

fromSMRandATRwithCCS.

Table28-CO₂emittedperkWhelectricityproduced.

ElectricityProductionMethod Value UnitPEMFCwithhydrogenproducedfromSMRwithCCS32:

0.12 kgCO₂/kWhel

PEMFCwithhydrogenproducedfromATRwithCCS:

0.04

KgCO2/kWhel

Largegasturbine[42]: 0.43 kgCO₂/kWhel

LargeCombinedCycleGasTurbine(CCGT)powerplant[42]:

0.29 kgCO₂/kWhel

TheCO₂emissionsfromproducingthesameamountofelectricityinalargeNGfiredCCGTpowerplant

isalmostsixtimestheemissionswhenproducingelectricitywithhydrogenfromATR.ToreformNG

tohydrogenbeforeproducingelectricityisthereforeaneffectivewayofreducingCO₂emissions.

Theresultsofthisanalysisshowthatdespiteahighercost,hydrogenproductionwithCCStriggers

great environmental benefits. The avoidance of CO₂ emissions by the utilization of the produced

hydrogen are significant. The estimated energy efficiency of producing electricity from NG via

hydrogenisapproximately50%usingSMR33,whileaLargegasturbineefficiencyofmax39%andLarge

31CO₂avoidedusinghydrogenfromSMR+CCSasfuelinFCVreplacingpetrolvehicle.Assumedpetrolengineefficiencyof30%andPEMFCefficiencyof60%.32AssumingPEMFCefficiencyof60%[52].SMRandATRsystemsdefinedinChapter3.33ATREfficiencyof82%.PEMFCefficiencyof60%.Bareinmindthatdistributionofhydrogenisnotincludedhere.Neitherisdistributionofnaturalgasorpowerintheturbinecases.

69

gasfiredCCGTpowerplantefficiencyofmax58%isassumed[42].Hence,foragivenquantityofNG,

astate-of-the-artCCGTpowerplantproduces16%moreelectricitycomparedtopowerproduction

fromhydrogen,butemits240%moreCO2.

Table29showsSMRcomparedtoATRwithdifferentlevelsofemissions.Becausethecarbonrecovery

isvariable,thecostofCCScanbereducedbyloweringtherecoveryrate.ATRversion2hasthesimilar

emissionlevelasSMR.AnimportantdetailtobefoundfromTable29isthecostofimprovedCCSin

theATRsystem.IfboostingthecapacityfromATRversion2toATR,6eurocentswillbeaddedperkg

ofhydrogeninordertoavoidapproximately900tonnesofCOemissionseveryday.Thatissubstantial.

EliminatingCCSentirely,thebreakevenpriceofATRisestimatedtobe1.22€/kgofhydrogen.Hence,

frommaximumemissionsto92%capture,thepricepremiumofCCSis0.37€/kg.A30%priceincrease,

includingCO2tax.Thismayindicateaneedforpolicysupport inordertobecost-competitivewith

traditionalhydrogen.

Table29-ThistableshowshowthebreakevenpriceofATRwilldifferwhenvaryingtheCCScapacity.ATR2isacasewithsimilarcarboncaptureasSMR.ATR3hassimilaremissionlevelasSMR

SMR ATR ATR2

BreakevenPrice€/kgH2: €1.51 €1.59 €1.53CO2emissions[tonnesperday]: 1198 318 1198CO2captured[tonnesperday]: 3047 3816 2936

5.7 SensitivityAnalysis

Astudyofhowthedifferentsystemsrespondtochangesininitialconditionsisimportantinorderto

getacompleteoverview.Inprojectswithalifetimeof25yearsandinitiationwithinaminimumof5

years,itisdifficulttoestimatecorrectconditions.Thissensitivityanalysisconsistsofthreeparts.First

isatechnicalcasepresentation,estimatinganoptimisticandaconservativescenarioofthedifferent

systems,providingarangewithinthesystemshouldbeoperating.Further,theeffectofchangesin

specificfinancialvariablesaretested,keepingallothervariablesconstant.Attheendisapresentation

ofhowthesystemsareaffectedbyaselectionoftechnicaldesignconditions.

5.7.1 OptimisticCaseandConservativeCaseScenarios

Inordertogetamorenuancedviewofthedifferentsystems,anoptimisticandconservativescenario

wasdefined.ThemainchangesareonCAPEXscalingcoefficientsandhydrogenyieldoftheproduction

processes.ThespecificdetailsofthescenariosarelistedinAppendixA.

70

Figure29-RangeofBreakevenpriceofhydrogenproduction.

Theresultsofthescenarioanalysis ispresented inFigure29.Asthediagramindicates,SMRisthe

mostcost-efficientproductionmethodforcarbon-leanhydrogen.ATRversion2systemisincluded,in

ordertoshowtheeffectofincreasedemissionshasontheviability.Thenewversion,similartothe

oneinTable29,hasthesameemissionlevelasSMR,byadjustingtherateatwhichtheabsorption

columncapturestheCO2.

SincethesimulationsdoneinChapter4areassumedsteadystatewithreactionsreachingequilibrium,

the results are ideal, given the chosen input parameters. In real operation, catalysts will enable

reactionstoapproachequilibrium,butnotperfectly,asinthesimulations.Becauseofthis,variation

oftherecoveryofhydrogeninthePSAisincludedintheoptimisticandconservativecases.

5.7.2 ChangesinenergyinputCost

Althoughconsiderableuncertaintiesarerelatedtoinvestmentcostsandmaintenance,variationsin

feedstock costs are certain to occur and will affect the overall viability of the different systems

significantly.Inhydrogenproduction,thevolatilepricesofenergyinput,intheformofnaturalgasand

electricity,dominate.Worldwide, theelectricitypricehasbeenclosely related to thecostof fossil

resources.Withtherecentdevelopmentsinrenewables,thisisnotnecessarilythecaseinthefuture,

henceascenariowithhighcostnaturalgasandcheapelectricityispossible,andviceversa.InNorway,

the electricity price is not directly affected by the natural gas price. On the other hand, with an

increasingexportcapacityofpowertonorthernEuropeancountries,arapidincreaseinfuelcostsmay

71

promote further export and lower supply in the homemarket. This sectionwill present how the

differentsystemsreacttochangesinenergyinputcost.

Figure30-Breakevenpriceofhydrogenwithchangesintheelectricityprice.

AscanbeseenfromFigure30electrolysisishighlyaffectedbythechangesinelectricitycost.Note

thatbelowapproximately16€/MWhitisthemostcost-efficienthydrogenproductionmethodforthe

500tonnes/daycapacity.Theaverageelectricitypriceusedinthisthesisis20.03€/MWh[35].Thisis

basedontheNASDAQcommoditiesENOYR16-19asmentionedinSection5.3.5.Itisevidentthatthe

priceusedislowcomparedto33.88€/MWh,whichwastheaveragepriceofpowerintensiveindustry

inthefirstquarterof2016[43].Thelatterpricewouldhaveresultedinabreakevenpriceof2.51,1€

moreexpensivethanthepriceofhydrogenfromSMRatthesameelectricityprice.Thisissignificant,

andimpliescaution.Electrolysis industry is includedinthepower intensivesegment,althoughone

canarguethathydrogenproductionisfundamentallydifferentfrommetalprocessingusingthesame

“electrolysis”.Inthecaseofhydrogen,itisenergystoragefordistributionorexport.Eitherway,the

price of electricity is volatile and provides high risk in the case of such large-scale production of

hydrogen.

Norwegianelectricityprice:20.03€/kWh

72

Figure31-Breakevenpriceofhydrogenvs.naturalgasprice.

Figure31plotshowthesystemsrespondtochangesinnaturalgascost.Here,animportantvalueis

thecostatwhichelectrolysisout-competethereformingprocesses.Thisoccursatapricearound0.24

€/Sm3.Assumingthepriceofnaturalgasincreasetothislevel,fromthecurrent0.17/Sm3,itisfairto

assumethatitwillhavesomeeffectontheelectricitypriceaswell.Therefore,ascenariowherethe

energyinputcostsvarywiththesamerateofchangeisshowninFigure32.

Figure32-Breakevenpriceofproducedhydrogen,givennaturalgasandelectricitypricesfluctuateatthesamerate

Norwegiannaturalgasprice:0.17€/Sm3

73

Figure 32 clearly shows that in a scenario where the cost of natural gas and electricity changes

similarly, the reforming systems are more stable in the response, meaning higher risk for pure

electrolysis.Thepricetargetofhydrogenforexportwasestimatedtobe1-2€/kginordertobecost-

competitive,asstatedinSection5.2.AscanbeseenfromFigure32,onlySMRandATRwillproduce

hydrogenwithinthistargetrangeevenwithanaturalgaspriceincreaseof50%.

Asthefiguresinthissectionshow,CREisneverthemostcost-efficienthydrogenproductionsystem.

If the electricity price drops, electrolysis will be the preferable method. If the electricity price

increases,naturalgasreformingalonewillbesuperior.Theeffectofnaturalgaspricechangeswillbe

similar,withreformingmethodsdominatingatlowNGpricesandelectrolysisathighfeedstockprices.

Althoughneverthebestalternative,CREisalsonevertheworst,meaningthatgivenfutureNGand

electricitypricefluctuations,CREhasamorestableresponse.Thismayreducetheriskofsuddenprice

increasesandisanimportantstrengthofthecombinationsystem.

5.7.3 CarbonTax

WithEuropeanpoliticsfocusingoneffectivemeasurestoreduceemissions,itisnaturaltostudythe

systemsresponsetoanincreasingpriceofCO2emissions.Theresultsofthissensitivityanalysis,shown

inFigure33,isveryinteresting.Firstofall,acarbonpricecloseto60€/tonneCO2isneededinorder

tomakecarbon-leanhydrogencost-competitivewithhydrogen fromtraditionalSMRwithoutCCS.

Thatisasignificantvalue,consideringthecurrentaveragecarbonpriceinEuropeis7.7€/tonneCO2.

That is an 800% increase. Interestingly, the emission permits in Europe cost 30€/tonne of CO2

equivalentsin2008[44].Anotherinterestingresultisthatevenwithacarbonpriceof100€/tonne

CO2SMRstillproducehydrogenatalowercostthanelectrolysis.

74

Figure33-Breakevenpriceofhydrogenvs.costofCO2emissions.SMRwithoutCCSisaddedinordertoseehowhighthecarbonpricemustbeinorderforcarbon-leanhydrogentobecost-competitive

5.7.4 SystemDesignVariations

In thissection, thespecificcompetitivenessof individualsystemswillbeanalysedbychangingkey

performance variables. First, a study of how the production volume affect the overall viability is

presented.Thisisimportantformanyreasons.Ifalarge-scaleproductionfacilityistobemade,apilot

projectwith lowerproductioncapacity is aneffectiveway to reduceoverall risk.Also, inorder to

determinewhichmethodtochoose,themarketdemandisdecisive.Ifthetotaldemandwillbe500

tonnes per day, five distributed electrolysis plants may be a better alternative than one large

centralizedSMRfacility.Bysmall,mediumandlarge-scaleproduction,0-25,25-100andabove100

tonnesofhydrogenperdayisusedinthisthesis,respectively.

75

Figure34-Breakevenpriceofhydrogenvs.productioncapacity.Mindthechangeonthex-axisfrom100to500tonnes/day.

AsFigure34clearlyindicates,electrolysisisthebestavailableoptionforsmalltomediumscalecarbon-

leanhydrogenproduction.Thisisunexpected,basedonthecurrentproductionworldwide,butthe

mainexplanationisthelowcostelectricityavailableinNorway.Duetomodularity,thescaleeffects

of electrolysis are limited. The cost of electricity, on the other hand, has a large effect on the

productioncost,asseeninFigure30.Iftheelectricitypricestaysonthelevelsprojected,electrolysis

will be a favoured production method to supply most of the domestic demand. But only slight

variationsintheelectricitypricecanchangetheoverallpicture.

AnotherinterestingdetailtoreadfromFigure34istherelativecostdifferenceofATRandSMR.SMR

isconsideredasthefavourablemethodofhydrogenproductionfromnaturalgas.Thereasonasto

whyisbasedonhighconversionratesandtheexpensiveoxygenproductionplantrequiredbyATR.In

large-scaleoperation,thisrelativeinvestmentcostdifferencediminishesduetoeconomiesofscale,

improvingthecost-competitivenessofATR.Important,asitrepresentsanalternativewith70%less

CO2emissions.

Figure35showshowtheenergyefficiencyoftheelectrolysisplantaffectthebreakevenprice.The

plantanalysedinthisthesishasaplantenergyefficiencyof76%.Someimprovementstotheoverall

efficiencycanbeassumedduetoresearchanddevelopment,butascanbeseenfromthefigureithas

tobeclosetothetheoreticalmaximuminordertobethemostcostefficientmethodforlarge-scale.

Sincethenaturalgassystemsarematuretechnologieslimitedtoincrementalimprovementsaswell,

76

theoverallsystemcompetitivenesswillmainlybebasedonCAPEXlevelandfeedstockcosts inthe

nearfuture.

Figure35-Breakevenpriceofhydrogenvs.energyefficiencyoftheelectrolysisplant.

5.7.5 FinancialMarketChanges

Thefinancialmarketsarechallengingtopredict.Therefore,adisplayofhowthebreakevenpriceof

hydrogenchangewiththeoverallfinancialsituationisdone.Figure37AandBshowtheresultsina

strictand inacalmfinancialmarketscenario, respectively. Inastrict financialmarket, in thiscase

definedwithadiscountrateof15%duetohighrisk,ahighOPEXtoCAPEXratio ispreferred.This

benefitselectrolysis,whichismorecompetitivehere,thaninthecalm,lowriskscenario.

Figure 37 - Breakeven price of Carbon-lean Hydrogen.Strict financial market. 15% discount rate. 20 yearslifetime

Figure36 - Breakevenprice of Carbon-leanHydrogen.Calm financial market. 7% discount rate. 30 yearslifetime

77

5.8 Techno-EconomicEvaluationofLarge-scaleHydrogenProductioninNorway

Estimatingwhich hydrogenproductionmethod is themost cost-efficient is difficult. As this thesis

statescarboncaptureasaprerequisiteforthebroadacceptanceofhydrogenasanenergycarrierof

thefuture,thedecisionisevenmorecomplicated.Thetwomostimportantquestionstoanswerin

thissectionare:Whatisthecostofproducingcarbon-leanhydrogeninNorway,andwhatistheprice

premiumoffurtherreducedemissions?

Chapter4providesathoroughtechnicalanalysisoflarge-scalehydrogenproduction,showingbenefits

anddisadvantageswith thedifferent systemsavailable. Focusingonenergyefficiency,natural gas

consumption and carbon emissions, the analysis covers the important factors in a choice of

technology.AscanbeseeninChapter4,ATRandSMRaretheleadingtechnologieswithregardsto

plantenergyefficiency.Itisimportanttohighlightthelimitationsofsteadystatesimulationslikethe

onesperformedinthisthesis,buttheresultsenablecomparisonandprovidepreliminaryestimations.

Giventhefeedstockpricesusedinthisthesis,thebreakevenpriceofhydrogen,ina500tonnes/day

facility, ranges from1.51 €/kgwith SMR, to 1.76 €/kgwith electrolysis. For production capacities

belowaround150tonnes/day,electrolysisispreferred.Aninterestingresultisthesmalldeviationin

theproductioncostofthedifferentmethods.Onecanassumethatabenchmarkcostofhydrogen

produced under normal, Norwegian conditions will be in this range. This assumption is also

strengthenedby the comparisonwith theH2A report in Section5.5. In Section5.2, aprice target

between1and2€/kgwasdefinedasaprerequisiteforeconomicviabilityinanexportscenario.This

thesisshowsthathydrogenproducedfromnaturalgas,electrolysisoracombinationallmeetthecost

target.

Carbon-leanhydrogencanbeproducedlarge-scaleinNorwayatabreakevenpriceof1.50-1.75€/kg

Ascanbeseenbelowin

Table 30, even with equal emission levels, SMR has the lowest production cost. However, the

difference toATR is barely 2 percent,meaningATR could verywell prove to be better. Since the

currentestimatedproductioncostofcarbon-leanhydrogenfromATRandSMRareclosetoidentical,

it is not possible to concludewith a preferredmethod. An argument in the favour of ATR is the

opportunitytoincreasetheCCSrate.

78

Table30-Keyfiguresfromthetechnicalandfinancialanalyses.

KEYFIGURESINTHISThesis Unit SMR SMR+ ATR Electrolysis CREProductionTechnology:

Steammethane

Reforming

Steammethanereforming

Autothermalreforming

Alkalineelectrolysis

Combinedautothermal

reformingandelectrolysis

H2Productionrate:

kg/day 500000 500000 500000 500000 500000

AnnualConsumptionofNaturalGas:

Sm3/day 78826 82844 76776 - 55630

GridPowerdemand:

MW 15 19 43 962 349

TotalPlantenergyefficiency(LHV-based):

82% 78% 82% 62% 74%

Electricityprice: €/MWh 20.03 20.03 20.03 20.03 20.03Naturalgasprice:

€/Sm3 0.17 0.17 0.17 0.17 0.17

TotalCAPEX: M€ 889.0 1071.0 972.4 582.8 860.4TotalOPEX: M€ 164.6 178.5 168.9 240.9 191.0BreakevenPriceofhydrogen:

€/kg 1.51 1.71 1.59 1.76 1.65

CO2Emissions: TonnesofCO2perday

1198 547 318 - 244

CO2Stored: TonnesofCO2perday

3047 3913 3816 - 2752

PricepremiumofCCS:

€/kgH2 0.32 0.38 0.37 - 0.30

SpecificcostofCCS:

€/kgCO2 0.053 0.049 0.048 - 0.055

Manyfactorswillaffecttherealpriceofhydrogenproduction,likegovernmentsubsidies,quoteand

thechosencompany’stechnologicalhistory.Themostimportantresultofthisthesisistoshowthat

thereareviablealternatives toproducecarbon-leanhydrogen inNorway,either fromnaturalgas,

electrolysisorincombination.Inanunstableenergymarket,withlargevariationsinfeedstockcosts,

thecombinedreformingandelectrolysismethodcanproveeffective.Aswellas itprovidesagood

opportunityfortechnologydevelopmentinavarietyofareas.

79

Inorder tominimizecarbon footprint,ATR,CREorpureelectrolysis represents thebest solutions.

AlthoughSMRrepresentsasolutionwithmoreCO2emissions,givennopostcombustionCCS,itwill

alsocontributetoasignificantemissionreductionintheenergyvaluechain.ATRhasahighflexibility

withregardstoCCScapacity,enablinganimpressive92%captureratesolelywithpre-combustion,

andstillprovingeconomicallyviable.ThepricepremiumofcarboncaptureislowestinSMR,asseen

in

Table30,butthatistheresultoflimitedcapture.Alevelizedcostof0.048€perkgofcapturedCO2in

ATRprovestheeffectivenesshydrogenrepresentsasameantocutemissions.Andthatvaluedoes

notincludetheavoidedCO2theuseofhydrogenwouldimplyifreplacingotherenergycarriers.

80

6 A Case Study Approach to Hydrogen Production Combining Gas

ReformingandElectrolysis

To this point, the thesis has presented and evaluated different systems for large-scale hydrogen

production,bothtechnicallyandeconomically.TheresultsindicatethatbothSMRandATRarecost-

efficienthydrogenproductionmethodsinafuture,carbon-leanenergysystem.Withthistakeninto

consideration, the breakeven price of CRE is not significantly higher than ATR, 1.65 €/kgH2 to

1.59€/kgH2.Further,thesensitivityanalysisdemonstratesthatCRE is lessresponsivetochanges in

energyinputcosts,comparedtoeitherpureATRorpureEL.AsFigure30shows,atagridelectricity

pricebelowapproximately16€/MWh,CRE is lessexpensivethanATR.Therefore, thischapterwill

evaluatethepotentialforCREtoreducetheelectricitycost,byutilizingexcesswindpower,andthus

becomeamorecost-efficientalternativethanATR.

DuetotheavailablenaturalgasfromtheHeidrungasfieldandtherecentconfirmationofStatkraft

plansforthebiggestwindfarminEurope,locatedaroundFosenandSnillfjorden[45],Mid-Norway

waschosenasthecaselocationinthisstudy.Here,strandednaturalgas,abundantwindresources

andavailablecarbonstoragealternativescreateoneofthemostadvantageous locationsfor large-

scalehydrogenproductioninNorway.

Figure38-ThemapshowsthelocationoftheFosen/Snillfjordenwindfarms.ThereddotmarksthelocationofTjeldbergoddenIndustrialComplexandtheHeidrungas-receivingterminal.Photo:Statkraft[45].

81

Hydrogenstoragehasnotbeenincluded,specifically, inboththetechnicalandfinancialanalysisof

these cases, due to the use of themodels evaluated in Chapter 4 and 5, but the implications of

hydrogenstorageisdiscussedintheendofthischapter.

Following, two sets of cases will be evaluated; a set of stationary production cases and a set of

fluctuating production cases. The stationary cases will provide the reference values in order to

measurethepotentialgainofallowingfluctuations.Theonlyfeedstockboundaryofthecasestudies

isthecapacityofnaturalgasfromtheHeidrunfieldavailable.Powerdemandbeyondthecapacityof

thewindfarmwillbesuppliedbythegrid.

6.1.1 TjeldbergoddenIndustrialComplex

Tjeldbergoddenindustrialcomplexconsistsofthreeparts;anaturalgasreceivingterminalfromthe

Heidrun field, amethanol plant and an air separation facility [46]. Tjeldbergodden has an annual

productioncapacityofapproximately900000tonnesofmethanol,an impressive25%of thetotal

Europeancapacity.An importantfactorforchoosingthis locationforthecasestudy istheexisting

syngasproductionalreadyinoperation.Themethanolplantutilizesatwo-stepreformingbenefitting

fromboththecost-efficiencyofSMR,aswellastheflexibleH2/COratioofATR[47].Theprocessing

facilityatTjeldbergoddenisnotutilizingthefullNGcapacityoftheHaltenpipepipelinefromHeidrun.

The maximum NG capacity is 7 MSm³/day where approximately 2.2 MSm³/day are used in the

methanolplant[48][20].Hence,around4.8MSm³/daypotentialcapacityisavailableforotheruse.

6.1.2 FosenandSnillfjordenWindFarm

In2020,thelargestonshorewindprojectinEuropewillbeinoperation.Distributedatsixlocations

along the coast ofMid-Norway, the Fosen and Snillfjorden wind farm will represent an installed

capacityof1000.8MW,deliveredby278individual3.6MWwindturbines[45].Thetotalscheduled

productionis3400GWh,implyingacapacityfactorof0.388[49].

6.2 StationaryProduction

6.2.1 StationaryCase1,NaturalGas-basedCo-productionofHydrogen:

Stationarycase1willusethemaximumavailableNGatTjeldbergoddeninthehydrogenproduction.

UsingtheCREsystem,additionalhydrogenisproducedbyelectrolysis,whileprovidingtherequired

oxygen to the reformer. In this case study, all powerwill be supplied by the grid, at the average

electricitypriceusedthroughoutthethesis.TheresultsofthestudyarelistedinTable31.

82

Table31 - Stationary case1 results. The full naturalgas capacity is used,withelectrolysers supplyingoxygenaswell asproducingadditionalhydrogen

Stationarycase1 Value Unit

Naturalgasdemand: 4.8 MSm3/day

Naturalgasavailable: 4.8 MSm3/day

Designcapacityelectrolysis: 1117 MW

AnnualAveragecapacitywindfarm: 388 MW

Maximumcapacitywindfarm: 1000.8 MW

Operatingdays: 347 Days/Year

Naturalgasprice: 0.17 €/Sm3

Electricityprice: 20.03 €/MWh

H2producedbyelectrolysis: 497 Tonnes/day

H2producedbyATR: 1301 Tonnes/day

Totalhydrogenproduction: 1798 Tonnes/day

TotalCAPEX: 2262.8 M€

TotalOPEX: 638.5 M€

Breakevenpriceofhydrogen: 1.42 €/kgH2

Specificproductioncostfromelectrolysis: 1.76 €/kgH2

AsTable31shows,theavailablenaturalgasatTjeldbergoddenenablesaproductionof1800tonnes

ofhydrogen/day.Thisresultsinabreakevenpriceof1.42€/kgofhydrogen,a15%reductionfromthe

capacityevaluated inChapter5.Sincethe limitedNGenablesCREtoproduceadditionalhydrogen

comparedtoreformingalone,thepotentialforCREtoachievelowerproductioncostexists.Table32

showsthatthisisnotthecase.Evenwithlowerproductioncapacity,ATRisevenbetterrelativeto

CRE, compared to results in Chapter 5. Hence, CRE would not be the preferable alternative for

stationaryproductionofthissize.

Table32-Stationarycase1:Benchmarkbreakevenpriceofhydrogenproduction,giventhesamefeedstockdemands

SMR ATR Unit

Hydrogen

produced:

1268

1303

Tonnes/day

Breakevenprice: 1.33 1.33 €/kg

83

ThiscasestudyshowsthattheNGavailableatTjeldbergoddenissufficienttosupplyaconsiderable

futurehydrogenmarket,withalmostthreetimestheNGrequiredofthesystemsinChapter4and5.

Althoughanunrealisticproductioncapacity,theresultdemonstratesthevastpotentialoftheenergy

resourcesavailableinthisgeographicalarea.

6.2.2 StationaryCase2,Wind-basedCo-productionofHydrogen:

Analternativetocase1istodesigntheproductionbasedontheannualaveragepowerproduction

fromtheFosen/Snillfjordenwindfarm.Whenfinalized,thetotalwindpowercapacitywillbe1000

MW.Withanestimatedcapacityfactorof0.388,theaverageannualpowerproductionis388MW,

whichwillbethedesigncapacityoftheelectrolysisplantinthiscasestudy.Asinstationarycase1,all

electricitywillbesuppliedbythegrid,attheaverageelectricityprice.Theoxygenproducedwillbe

thedesignparameterfortheautothermalreformingplantpartoftheproduction.

Table33-Stationarycase2results.Thesystemisdesignedbasedontheannualaveragepowersupplyfromthewindfarm.TheparallelATRsystemisdesignedbasedontheproducedoxygen.

Stationarycase2 Value Unit

Naturalgasdemand: 1.67 MSm3/day

Naturalgasavailable: 4.8 MSm3/day

Designcapacityelectrolysis: 388 MW

AnnualAveragecapacitywindfarm: 388 MW

Maximumcapacitywindfarm: 1001 MW

Operatingdays: 347 Days/Year

Naturalgasprice: 0.17 €/Sm3

Electricityprice: 20.03 €/MWh

H2producedbyelectrolysis: 173 Tonnes/day

H2producedbyATR: 452 Tonnes/day

Totalhydrogenproduction: 625 Tonnes/day

TotalCAPEX: 1017.4 M€

TotalOPEX: 233.3 M€

Breakevenpriceofhydrogen: 1.59 €/kgH2

SpecificproductioncostformATR 1.50 €/kgH2

Specificproductioncostfromelectrolysis: 1.83 €/kgH2

84

Table33presentstheresultsfromthecasestudy.ThebreakevenpriceofCREwiththeseboundary

conditionsis1.59€/kgH2,whichisclosetothevaluesofSMRandATRusingthesameNGfeed,seen

in Table 34. The specific production cost of the hydrogen produced by electrolysis is 1.83 €/H2,

highlightingtherelativecost-differenceofATRandELinthecombinationsystem.1.59€/kgH2isthe

referencepriceusedinthefluctuatingcasesofSection6.3.

Table34-Stationarycase2:Benchmarkbreakevenpriceofhydrogenproduction,givensamefeedstockdemands

SMR ATR Unit

Hydrogenproduced: 440 452 Tonnes/day

Breakevenprice: 1.53 1.56 €/kg

6.3 FluctuatingProduction:

An alternative to the stationary case 2 is to let the electrolysis part of the total production be

dependableontheavailablewindpowersuppliedbytheFosen/Snillfjordenwindfarm.Inotherwords,

design theelectrolysers such that theprocess is able toutilizeperiodsof strongwindsandhence

potentiallylowerelectricityprices.ThiswillontheotherhandincreasetheCAPEXoftheelectrolysers

duetorequiredincreaseintheelectrolyserproductioncapacity.Thestudydoesnottakeintoaccount

thechallengesof fluctuation inreal timeoperation,butexaminestheoveralleconomicviabilityof

suchasystemintermsofincreasedCAPEXversusreducedcostofelectricity.

TheATRpart of the CRE system is in all the fluctuating cases assumed to produce hydrogen at a

constantrate,andcaseswillproducethesametotalamountofhydrogenasthestationarycase2.It

isreasonabletoassumealowerelectricitypricewhenutilizingexcesspowerfromthewindfarm,but

theexactvalueishardtopredict.Therefore,theelectricitypricerequiredforthebreakevenpriceto

reachthereferencepricefromstationarycase2,1.59€/kgH2,isestimated.

6.3.1 FluctuatingCase1:PartlyFlexibleElectrolysis

Thiscaseenablestheproductionfacilitytoutilizesomeoftheexcesswindpowerwhendemandis

low, but limits the installed electrolyser capacity to 600 MW, approximately 60 percent of the

maximumwindpowercapacity.TheresultsofthiscasestudyarelistedinTable35.

85

Table 35 - Fluctuating case 1: Partly flexible electrolysis with an electrolysis capacity of 600MW. Highlights from thesimulationispresentedhere.ShowingtheBreakevenpriceofthehydrogenproducedaswellastherequiredelectricitypricetoequalthereferencepriceofstationarycase2.

AscanbeseenfromTable35,thebreakevenpriceofthiscasedesignis1.67€/kgH2,giventheaverage

electricitypriceusedinthisthesis.Inordertoachieveabreakevenpriceequaltothereferenceprice

instationarycase2,anelectricitypriceof14.75€/MWh isnecessary.Whetherornot thisprice is

achievable is hard to predict, but in order for theCRE system to be less expensive thanATR, the

electricitypricemustbelowerthanthisvalue.

Thewindpowersupply factor is0.81,whichmeans that81%of theannual requiredpower in the

electrolysisplantisdirectlysuppliedbythewindfarm.Thewinddatausedtocalculatethewindpower

supplyfactorispresentedinAppendixC.Theremaining19%ofthepowerproducedbythewindfarm

isdeliveredtothegrid,whilethegriddistributesthissameamountofthepowertotheelectrolysers

inperiodsofcalmweather.

6.3.2 FluctuationCase2:FlexibleElectrolysis.

Thiscasestudyevaluatesthescenariowheretheelectrolysisplantisdesignedtomeetthefullcapacity

ofthewindfarm.SuchahighcapacityimpliesasignificantincreaseinCAPEX,butenablestheplantto

34Thewindpowersupplyfactoristhepowerdirectlysuppliedbythewindfarm,dividedbythetotalpowerdemandoftheelectrolysisplant.ThewinddatausedtocalculatethewindpowersupplyfactorispresentedinAppendixC.

Value UnitElectrolyserdesigncapacity: 600 MWElectrolyserdesignproductioncapacity: 267 Tonnes/dayAverageH2producedbyelectrolysis: 173 Tonnes/dayOperatingdays: 347 Days/yearELprice: 20.03 €/MWh Result: Breakevenpriceofhydrogen: 1.67 €/kgH2SpecificproductioncostfromATR: 1.50 €/kgH2Specificproductioncostfromelectrolysis: 2.11 €/kgH2Windpowersupplyfactor34: 0.81 Electricitypricetoreachreferenceprice: 14.75 €/MWhElectricitypricetoreachtheATRbreakevenpriceof1.53€/kgH2:

10.77 €/MWh

86

leverageonalltheavailablelow-costelectricityinperiodsofrelativelyhighsupply.Table36shows

theresultsofthecasestudy.

Table36-Fluctuatingcase2:Flexibleelectrolysis,withcapacityof1000MW.Highlightsfromthesimulationispresentedhere.ShowingtheBreakevenpriceofthehydrogenproducedaswellastherequiredelectricitypricetoequalthereferencepriceofstationarycase2.

AsseeninTable36,thebreakevenpriceis1.81€/kgH2ifusingtheoriginalelectricityprice.Sincethis

caseutilizesthefullcapacityofthewindfarm,themaximumpossiblereductionintheelectricityprice

isachieved.Theelectricitypricerequiredtoreachthereferencepriceof1.59€/kgH2isestimatedto

be5.24€/MWh,a74%reductionfromtheoriginalgridelectricityprice.

6.4 IsCombinedReformingandElectrolysisaCompetitiveSolution?

ThischapterevaluateswhetherornottheCREsystemcanutilizeexcesswindpowertoreducethe

electricitycostandthusbecomemorecost-efficientthanATR.TheresultsinChapters4and5indicate

thatproducinghydrogenexclusively fromnaturalgasreformingconstitutesthemosteconomically

viablebusinesscases.Thissectionwilldiscusswhetherornottheresultsofthecasestudiesprovidea

differentconclusion.

35Thewindpowersupplyfactoristhepowerdirectlysuppliedbythewindfarm,dividedbythetotalpowerdemandoftheelectrolysisplant.ThewinddatausedtocalculatethewindpowersupplyfactorispresentedinAppendixC.

Value UnitElectrolyserdesigncapacity: 1000.8 MWElectrolyserdesignproductioncapacity: 445 Tonnes/dayAverageH2produced: 173 Tonnes/dayOperatingdays: 347 Days/yearELprice: 20.03 €/MWh Result: Breakevenpriceofhydrogen: 1.81 €/kgH2SpecificproductioncostfromATR: 1.50 €/kgH2Specificproductioncostfromelectrolysis: 2.63 €/kgH2Windpowersupplyfactor35: 1 Electricitypricetoreachreferenceprice: 5.24 €/MWhElectricitypricetoreachtheATRbreakevenpriceof1.53€/kgH2:

1.26 €/MWh

87

Thestationarycase1showsthattheenergyresourcesavailableatTjeldbergoddenaresufficientfor

large-scale production of hydrogen, with the feedstock to produce around 1300 tonnes of

hydrogen/dayusingATR.

AsseeninFigure39thewindpowersupplyfactoris0.81forthe600MWfluctuatingcase.Sincethe

cost of intermediate oxygen and hydrogen storage is not taken into account in this study, the

stationarycase2isequivalenttoafluctuatingcasewitha388MWelectrolysercapacity,providinga

windpowersupplyfactorof0.73.Hence,an11%increaseinthewindpowersupplyfactorwillneed

toprovidea25%electricitypricereductiontoequalstationaryCRE(from20.03to14.75€/MWh).

Figure39-Graphshowinghowtheelectricitypricerequiredtoreachthereferencepriceandthepowersuppliedbythewindfarmareaffectedbychangesinthedesignedelectrolysercapacity.

Mostimportantly,theresultsfromthecasestudiesshowthataCREsystemdesignedtoutilizeexcess

windpowerwillneedsignificantreductionsinelectricitypriceinordertobecost-competitive.Ifthe

systemisdesignedforthemaximalcapacityofthewindfarm,theelectricitypricehastobereduced

byalmost75%(from20.03to5.24€/MWh),onlytoachievethesamebreakevenpriceasstationary

CRE.ThisrelationispresentedinFigure39.InordertoreachthebreakevenpriceofATR,therequired

electricitypriceis1.26€/MWh,areductionof94%.Therefore,theresultsofthecasestudiesindicate

88

that,giventheboundaryconditionsinthisthesis,acombinedelectrolysisandreforming(CRE)system

utilizingexcesswindpowerisnotlikelytobecost-competitivewitheitherstationaryCREpoweredby

thegridortraditionalreforming.

Itisimportanttohighlightthattheestimatedelectricitypricereductionsdonotincludethecostof

intermediate oxygen and hydrogen storage required in the fluctuating production facilities. The

constantnaturalgas reformingoccurringsimultaneously,demandsasteady flowofoxygen,which

impliesaneedforastoragesystem.Thiswouldincreasethecostevenfurthermakingthefluctuating

casesevenlessviable.

89

7 Conclusion

Hydrogen is a promising energy carrier with the potential to reduce CO2 emissions from fossil

resources,integraterenewableswithsocietyandreplacefossilfuelsinthetransportationsector.The

idea of a hydrogen-based energy chain is not new, but with recent developments in renewable

industriesandpoliticalsupport,theconditionsareimprovingsignificantly.

Thisthesisprovidesatechnicalandafinancialanalysisofavailable,maturesystemscapableoflarge-

scaleoperation,inordertoevaluatethepotentialoflarge-scaleproductionofhydrogeninNorway.It

isdifficulttoprovidegeneralconclusionstobusinesscaseswithsuchuncertainboundaryconditions,

especiallywith regards to feedstockcostandmarketdevelopment,butbasedon theassumptions

thoroughlystatedthroughthethesis,thefollowingpointssummarizethekeyfindings.

Keyfindingsinthethesis:

Ø ATRandSMRarethemostenergyefficientalternativesforcarbon-leanhydrogenproduction,bothwithaplantenergyefficiencyof82%.ATRhas themostpotentialof furtheremissionreductions.

Ø SMRisthemostcost-efficientmethodforlarge-scaleoperationinNorway,producingcarbon-leanhydrogenatabreakevenpriceof1.51€/kgina500tonnes/dayfacility

Ø Thepricepremiumof72%reduction inCO2emissionsusingSMRwithCCS is0.32€/kgH2.ComparedtoSMR,ATRrepresentsanadditionalcostof0.08€/kgH2inordertofurtherreducetheCO2emissionswith70%.

Ø Given the assumed feedstock prices, electrolysis is the most cost-efficient alternative forproduction rates up to around 150 tonnes of hydrogen per day, while SMR is the bestalternativeforlarge-scaleproduction.

Ø Combined electrolysis and reforming (CRE) is not likely to become the most cost-efficientalternative,butislesssensitivetovariationsinfeedstockcosts.

Ø Theresultsof thecasestudies indicatethat,giventheboundaryconditions in this thesis,acombinedelectrolysisandreforming(CRE)systemutilizingexcesswindpowerisnotlikelytobecost-competitivewitheitherstationaryCREpoweredbythegridortraditionalreforming.

Fivesystemswerefullyevaluatedinthisthesis:SMR,SMR+,ATR,ElectrolysisandCRE.Allprovedto

beeconomicallyviablefordomesticconsumptionaswellasforexportscenarios,giventheassumed

costlevel.Duetokeytechnicalfactorsnotsimulatedandlackoffinancialdata,POXwasnotincluded

90

in the financial analysis. Electrolysis is the only zero emission alternative evaluated, and it proves

superiorinsmalltomediumscaleproductionplantsupto150tonnesofhydrogenperday,giventhat

thepriceofelectricityandnaturalgasremainsatthelevelusedinthisthesis.

Acasestudyofhydrogenproductionusingthecombinedreformingandelectrolysis(CRE)systemat

Tjeldbergoddenwasconducted.Theresultsshowedthattheenergyresourcesavailableisenoughto

produce1800tonnesperday.Amoreimportantresultfromthecasestudieswasthatutilizingexcess

power from a wind farm is not likely to reduce the electricity cost sufficiently in order to be

economicallyviable.

Theresultsofthisthesisindicatethathydrogenproductioncanutilizethevastenergyresourcesand

CCSpossibilitiesinNorwaytocreateviable,low-carbonenergyvaluechains.

91

8 ProposalsforFurtherWork

Multiplelarge-scalehydrogenproductionplantsexistaroundtheworldtoday,butthecombinationof

low-costresourcesinNorwayaswellasafocusonminimizingCO2emissionscreatesnewchallenges.

Themotivation for this thesiswas theopportunityof refiningNorwegian resources to create low-

emissionvaluechainsandinorderforthattobecomeareality,significantresearchremains.Inthe

caseofsmall-scaleproduction intendedfordomesticconsumption,therequiredtechnologiesexist

today,althoughthemarketisyettodevelop.Forlarge-scaleproductionintendedforexport,storage

andtransportationtechnologiesareunderdevelopment,buttheystillrequireconsiderableattention.

Thissectionwillprovidespecificproposalsforfurtherresearchintwocategories:Onegroupofspecific

areaswithin theproductionprocess,which require in-depth researchor cost-estimation, andone

groupofareaswithintheexportvaluechain.

8.1.1 Proposalsforfurtherresearchwithinthehydrogenproductionprocesses:

Ø Processcontrolandoff-designanalysis.Thisthesisassumesabasecasereliabilityof95%,

meaning that the plant operates at full capacity 347 days of the year. Both reactor

temperature and steam-to-carbon ratio requires intelligent control systems in order to

operateoptimally.Howdoesthesystemoperateinoff-designconditions?Transientoperation

mayalsooccur,especiallyduetothedirectconnectiontothegas-receivingterminal.Howcan

thesystemhandlestartandstop?

Ø Batchprocesssimulation.Theconnectionbetweenthecarbonabsorptioncolumnandthe

PSA,bothbatchprocesses,isnotsimulatedinthisthesis.Bothsystemsareassumed“black

boxes” with a base-case 95% recovery rate in the absorption and 90% in the PSA. These

systemsareveryimportantinordertoprovidehighcaptureandhighyield.Deviationsfrom

thebasecasewillresultinlargeresponseinthebusinesscase.

Ø Production design, sizing andplanning. Detailed cost-estimation of the entire facility and

evaluation of possible policy support and governmental subsidies. An export focus seems

most viable, resulting in the need for inclusion of a liquefaction plant, storage and an

offloadingterminal.Allofwhichincludedevelopingtechnologies.

92

Ø Demoplant.Constructionofademofacilitycantoprovidekeyoperationalexperienceand

reduce the risks related to full-scaleoperation.Combinedwith the fuellingofa ferryor in

cooperationwithATBinMid-Norway,thiscouldalsoassistinthepursuitoffurtherindustrial

andgovernmentalsupport.

8.1.2 Proposalsforresearchwithintheexportvaluechain:

Ø Hydrogenstorageandtransportation.Severalstudiesondifferenttechnologiesandmethods

forhydrogenstorageandtransportationhavebeenconducted,butawellstructuredoverview

of the alternatives is difficult to apprehend. In the case of Norwegian export, SINTEF

conductedapaperin2008,whichcanbeusedasinspiration.Onegoalcanbetoperforma

techno-economic analysis in order to benchmark the cost of storage and transport from

NorwaytoEuropeorJapan.Anothercanbeamoredetailedtechnicalstudyofthedifferent

alternatives,estimatingenergyefficiencies,carbonfootprint,viabilityandoptimization.

Ø Market studyof futurehydrogenconsumption inNorway.Although transportation is the

mostvisiblefutureconsumerthroughmedia,theannual,industrialdemandforhydrogenwas

more than 50million worldwide in 2015, emittingmore than 500million tonnes of CO2.

Projects likeTizir smeltingplant inTyssedal isanexampleofemergingpotentialhydrogen

demandintheNorwegianindustryaswell.Astudyoftheexistingindustrialhydrogendemand

inNorway,aswellasestimatingafuturecarbon-leanhydrogendemandcanbeanimportant

partofthedevelopmentofproductiontechnologyintheyearstocome.

93

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97

Appendices

98

A. FinancialAnalysis–elaboration

Equationforscaling

Inthecostestimations,scalingisactivelyusedinordertoestimatethecostofthecurrentcomponent

orfacilitybasedonareferencecase.Theequationused,iswrittenbelow.

]g = ]hPg

Ph

i

α–Scalingfactor

Cb–Basecost

Cx–Costforaplantofsizex(Sx)

Sb–Basesize

Currencytable:

Table37-Currencytable-AveragesFebruary-March2016

Currencytable

NOKtoEURO: 0.11

USDollarstoEuro: 0.90

SensitivityAnalysis

Scenariosensitivity

Here,thedetailsbehindtheoptimisticandconservativecasesareexplained.

SteamMethaneReforming:

Table38-Definitionoftheoptimistic,baseandconservativecaresimulationsforSMR

OptimisticCase BaseCase ConservativeCase

Prereformer:

Reformer+WGS: CAPEXofthereformer

isscaledfrom

400USD/kWwitha

CAPEXofthereformer

isscaledfrom

400USD/kWwitha

CAPEXofthe

reformerisscaled

from600USD/kW

99

scalingcoefficientof

0.7.

scalingcoefficientof

0.8.

withascaling

coefficientof0.9.

PSA: Assuminghydrogen

recoveryof95%.

Assuminghydrogen

recoveryof90%.

Assuminghydrogen

recoveryof80%.

CCSCAPEXscaling: 0.6 0.7 0.8

Compressors/Pumps: Assumingadiabatic

efficiency:Pump:85%,

Compressor:80%

Assumingadiabatic


Compressor:75%

Assumingadiabatic

efficiency:Pump:

70%,Compressor:

70%

Reliabilityfactor: 95% 95% 90%

Installationfactor: 10% 20% 30%

AutothermalReformer:

Table39-Definitionoftheoptimistic,baseandconservativecaresimulationsforATR


Prereformer:

Reformer+WGS: CAPEXofthereformer

isscaledwithascaling

coefficientof0.6.

CAPEXofthereformer


coefficientof0.7.

CAPEXofthereformer


coefficientof0.8.

PSA: Assuming hydrogen

recoveryof95%.

Assuming hydrogen

recoveryof90%.

Assuming hydrogen

recoveryof80%.

CCSCAPEXscaling: 0.6 0.7 0.8

Compressors/Pumps: Assuming adiabatic


Compressor:80%

Assuming adiabatic


Compressor:75%

Assuming adiabatic


Compressor:70%


Installationfactor: 10% 20% 30%

ExplanationtothescalingofATR:SincetheCAPEXoftheATRreformerisbasedonamuchlarger

facility,thescalingcoefficientworkoppositethanwithSMR.Hence,theCAPEXhasbeenscaleddown

totheSMRsourcefacilitywith0,7andscaleduptoATRsizewith0,6and0,8fortheoptimisticand

conservativecase,respectively.

100

Electrolysis:

Table40-Definitionoftheoptimistic,baseandconservativecaresimulationsforElectrolysis


Plantscalingfactor: 0,8 0,9 0,95


Installationcost

factor:

10% 20% 30%

PlantElectricity

consumption

[kWh/Nm3]:

4,7 4,85 5,0

ListofinputsandassumptionsusedforcostestimationsinExcel

Table41-Listofinputsusedforthecost-estimationsandnetpresentvaluecalculationsinEXCEL

GeneralInput Value Unit Descriction Source

Lifetimefacility: 25 Years

Operatingdays: 347 Days/Year Reliabilityof95% Dailyproductioncapacity: 500000 kg

AsaresultofanevaluationperformedintheProjectwork2015

Productionrate: 823 MWBasedonHigherHeatingvalueofthehydrogengasproduced

Areaspacerequired: 90000 m3

BasedonthemelkøyaLNGplantandscaledwitha0,7factortotheproductionvolumeevaluatedinthisthesis.

SMRBasecaseproductionrate: 300.00 MW

HHVH2.ThisisusedasthebasecaseforcostestimationsoftheSMRplant. IEATechnologyRoadmap

ASUBasecaseproductionrate: 496600.00 kgO2/h BasedonGLTreport

ASUpowerconsumption: 0.35

kWh/Nm3O2 BasedondatasheetfromLindeKryotechnic

http://www.ieaghg.org/docs/oxyfuel/OCC1/Plenary%201/Beysel_ASU_1stOxyfuel%20Cottbus.pdf

ATRandPrereformerBasecase: 339400.00 kgNG/hr BasedonGLTreport

PSABasecase: 14900.00 kgNG/hr BasedonGLTreport

WGSBasecase: 1000.00MW(HHVH2) Hydrogenproductionplant,fromcoalgasification.

CO2compressionwork: 0.10 kWh/kgCO2

BasedonasimplemodelinHYSYS,compressing1milliontonnesperyearfrom1to150bar.

CCSBasecasecapacity: 700000 tonnes/year BasedonthemelkøyaLNGplant AssumtionsbyprofessorJosteinPettersenElectrolysisBaseCasecapacity: 26000 kg/day NEL-Hydrogenbrochureoflargescalefacility Electrolysiscellstackconsumption: 50000 kW

101

Electrolysisplantspecificpowerconsumption: 4.85

kWh/Nm3H2

BasedonNELbrochureandinformationfromAkzoNobel.

Electrolysercellstackcatalystlifetime: 9.00 years

Basedontheaveragelifetimeofacellstackcatalyst.Spanfrom60000-90000hours IEATechnologyroadmap

ChemicalProperties Value Unit Description Source

HHVH2: 39.50 kWh/kg

LHVH2: 33.39 kWh/kg

DensityH2: 0.09 kg/Sm3

DensityNG: 0.83 kg/Sm3

MMH2: 2.02 kg/kmole

LHVNG: 12.91 kWh/kg

HHVPetrol: 9.47 kWh/L

Processinput Value Unit Description Source

NGTemperature: 50.00 degC SINTEFReport

NGPressure: 50.00 bara SINTEFReportProcessWaterTemperature: 15.00 degC

WaterPressure: 1.01 bara

OxygenT: 15.00 degC

OxygenPressure: 20.00 bara

Costinput Value Unit Description SourceBasecaseSMRPlant: 400.00 $/KW

Basedontheinvestmentcostofa300MW(HHVH2produced)plant.IncludingWGSandPSA IEATechnologyroadmapp.28

BasecaseATRreformer:

406582000.

00 $

BasedonaGTLcostanalysisreport,2500tonnH2/daycapacity,includingcostofengineeringandcontingencies

NationalEnergyTechnologyLaboratory,AnalysisofGas-to-LiquidTransportationfuelsviaFisherTropsch,2013

BasecasePOXPlant: BasecasetotalCO2captureplantInvestment: 800000000 NOK

Costofexpansionofprocessfacilitytoincludecapture,compression,drying,condensationandpumpingofCO2.Capacity:700000t/y

AssumtionsbyProfessorJosteinPettersen,basedonStatoilSnøhvit

BasecasetotalCO2transportinvestment:

120000000

0 NOK

Costofpipeline,8inches,140kmfromshoretosubseainjectionunit.200baradesignpressure,400mwaterdepth.Cap:700000t/y


BasecasetotalCO2injectionwellsystem: 600000000 NOK

CostofdrillingandcompletionofCO2injectionwell.Capacity700000t/y


AuxilliaryComponentfactor: 0.20

%/ProductionCAPEX

Thisfactorisaddedtoincludefeedwatersystems,coolingsystems,electricalsystem,controllsystems,buildingsandimprovementstosite


Installationfactor: 0.20

Whencostsofplantsandsystemsaregiven,thisfactorisaddedtocovertheexpensesrelatedtoengineeringandintallation

ElectricitypricefromNASDAQ: 20.03 €/MWh

AverageofNASDAQCommoditiesENOYR17,18and19onfrom18.04to16.052016.(20.03)

http://www.nasdaqomx.com/commodities/market-prices

Electricityprice: 0.18 NOK/kWh

ConvertedtoNOKperkWh.Incomparison,theaverageelpriceinTrondheimfrom14.04to13.052016was0,23NOK/kWh(NORDPOOL).

https://www.ssb.no/energi-og-industri/statistikker/elkraftpris/kvartal/2016-02-25

ElectricityGridprice: 230.00 kr/kW/year

StatnettTariffsfornationalgridconnection.Basedonthemaxpowerconsumptionneeded.

http://www.statnett.no/Drift-og-marked/Nettleie-og-tariffstrategi/Tariffer-i-sentralnettet/

NaturalGaspriceinEuros: 0.174 €/Sm3 Forsensitivityanalysis

102

NaturalGasprice: 1.58 NOK/Sm3

AverageinternalpriceofnaturalgasreportedbyStatoilin2015.Estimatedpricewhenmarketingandtransportationcostsarededucted.(1.58)

http://www.statoil.com/no/InvestorCentre/AnalyticalInformation/InternalGasPrice/Pages/default.aspx

CO2taxrateineuros: 7.70

€/tonnesofCO2 Forsensitivityanalysis

CO2taxrate: 69.98NOK/tonneCO2

Averageeuropeanquotaforcarbonemissions.(69,98NOK/Tonne)

http://www.miljodirektoratet.no/no/Tema/klima/CO2-priskompensasjon/Kvotepris-for-stottearet-2014/

Priceofindustryarea: 550.00 NOK/m3

http://www.finn.no/finn/b2b/commercialproperty/plots/object?finnkode=64408682&searchclickthrough=true

BasecaseCAPEXWaterGasShift:

40000000.0

0 $

BasedonareportpaperfromPrinceton,1000MW(HHVH2)capacity.Convertedfrom2002USDwithfactorof132,37%(usinflationcalculator.com)

PRODUCTIONOFHYDROGENANDELECTRICITYFROMCOALWITHCO2CAPTURE.Kreutz,Williams,Socolow

BasecaseCAPEXCryogenicASU: 299725000 $

BasedonaGTLcostanalysisreport,496000kgO2/hr,includingcostofbothengineeringandcontingencies


BasecaseCAPEXPressureSwingAdsorption: 12469000 $

BasedonaGTLcostanalysisreport,142000kgH2/day,includingcostofbothengineeringandcontingencies


BasecaseCAPEXPrereformer: 322704000 $

BasedonaGTLcostanalysisreport,2486000kgH2/day,includingcostofbothengineeringandcontingencies


BasecaseCAPEXElectrolysis:

€30000000 €

Basedon26tonnes/dayPlantbyNEL-Hydrogen.Producedto15barpressure

http://wpstatic.idium.no/www.nel-hydrogen.com/2015/04/NEL_Hydrogen_50MW.pdf

Reinvestmentcostcatalystreplacement: 20.00% %ofCAPEX BasedoninformationfromDNVGL H2andO2CompressorCAPEX: 70 USD/kW

Basedoncurrentperformanceofa180barhydrogencompressor.Thisisaveryconservativevalue IEATechnologyroadmap

OPEXRateNGReformingsystem: 5%

%ofCAPEX/year

OPEXRateCCSSystem: 5%

%ofCAPEX/year

FinancialInputs

USDtoEuro: 0.90 Averagecurrenciesfromfebruary-march2016 Oanda.com

NOKtoEuro: 0.11 Averagecurrenciesfromfebruary-march2016 Oanda.com

Discountrate: 0.10 Ref.Projectwork

Scalingfactors

SMR: 0.80 Statoil,JosteinSogge

ATR: 0.70 Statoil,JosteinSogge

POX: 0.70 Statoil,JosteinSogge

CCSsystem: 0.70 Statoil/NTNUProfessorJosteinPettersen

WGS: 0.70

ASU: 0.70

PSA: 0.90

Electrolysisplant: 0.90

103

B. TechnicalAnalysisEquationofstate

The Peng Robinson equation of state was chosen for the simulations in Aspen Hysys, due to its

common use in hydrocarbon process simulation. A test versus Soave-Redlich-Kwong and Kabadi-

Dannerwasdoneinordertocheckfordeviations,andtheresultsproveveryconsisten.

M = jk

6l − n−

Io

6l% + 2n6l − n%

I = 0.4572j%ku

%

Mu

n = 0.07780jku

Mu

o = (1 + 0.37464 + 1.54226x − 0.26992x% − 0.26992x% 1 − kz{.| )%

Where:

xistheacentricfactorofthedifferentcomponents

Pcisthecriticalpressure

Tcisthecriticaltemperature

Ristheidealgasconstant=8.314413J/mol-K

Table42-TestofEOS,withagivennaturalgasinputtotheSMRprocess.

PengRobinson Soave-Redlich-Kwong Kabadi-Danner

Naturalgasinput[kg/h]: 54000.000 54000.000 54000.000

Hydrogenproduced[kg/h]: 20983.729 20987.444 20979.031

RelativedifferencetoPR[%]: - 0.018 0.022

104

Electrolysis–technicaldetails

Thepowerconsumptionoftheelectrolysisplantusedinthisreportistheaverageconsumptionofthe

entirefacilityduringthelifetimeoftheoperation.Thisincludestheelectrolysercellstacks,rectifier,

feedwaterpump,lyepumpandproducthydrogencompressor.ThesourcesareHenningLangås,Nel-

Hydrogenand[34][12].

Table43-Electrolysisplantpowerconsumption

Value Unit

Plantpowerconsumption,newfacility: 4.7 kWh/Nm3

Plantpowerconsumption,atcatalystreactivation: 5.0 kWh/Nm3

AveragePlantpowerconsumption: 4.85 kWh/Nm3

SystemsHeatIntegrationData

Assumptions:

- TheheatdemandoftheCO2absorptionprocessisassumedtobe2MJ/kgCO2captured36.

- Duetothephenomenonofmetaldusting,explainedinSection4.3.2.2,thehotgasproduct

fromthereformerscanonlybeusedtoproducesteamthroughthetemperaturerangeof750

–400°C[50].

- Thefluegasisonlycooleddownto100°Cduetotheriskofacidformation36.

TheHeatintegrationdataisforallthereformingprocessespresentedin

Table44to

Table48.Asseenfromallthetables,thetotalheatproductionintheproductionplantisgreaterthan

theplantheatdemand.Theheatavailable inall systemsconsistsofenoughhigh-temperaturegas

streamstosupplythedemandingheatintheproductionplant.

36InformationprovidedbyDavidBerstad,SINTEFEnergyResearch

105

SMR:

Table44-HeatdemandandheatavailableinSMR

Value UnitHeatDemands: PreheatingWater(350°C): 487.3 GJ/hPreheatingGasinputinGHRandSMR(400and700°C): 172.7 GJ/hGHR(700°C): 130.3 GJ/hSMR(950°C): 714.9 GJ/hCO2Absorption(115°C)

36: 253.9 GJ/hPreheatingFurnaceinputs(335and500°C): 137.9 GJ/hTOTAL: 1897.0 GJ/h HeatAvailable: Coolingthereformingproduct(950-320°C): 389.6 GJ/hWGS(320-25°C): 380.7 GJ/hFurnace(1000°C): 714.9 GJ/hCoolingtheFlueGas(1000-100°C): 412.4 GJ/hTOTAL: 1897.6 GJ/h Difference: 0.6 GJ/h

SMR+:

Table45-HeatdemandandsourcesinSMR+

Value Unit

HeatDemands: PreheatingWater(350°C): 625.9 GJ/hPreheatingGasinputinGHRandSMR(400and650°C): 184.1 GJ/hGHR(700°C): 167.3 GJ/hSMR(950°C): 955.9 GJ/hCO2Absorption(115°C)

37: 326.1 GJ/hPreheatingFurnaceinputs(335and500°C): 186.0 GJ/hTOTAL: 2445.3 GJ/h HeatAvailable: Coolingthereformingproduct(950-320°C): 500.4 GJ/hWGS(320-25°C): 489.0 GJ/hFurnace(1000°C): 955.9 GJ/hCoolingtheFlueGas(1000-100°C): 501.9 GJ/hTOTAL: 2447.3 GJ/h Difference: 2.0 GJ/h


106

POX:

Table46-HeatdemandandheatavailableinPOX

Value UnitHeatDemands: PreheatingWater(320°C): 314.1 GJ/hPreheatingNGinputinPOX(400°C): 93.0 GJ/hCO2Absorption(115°C)

37: 327.6 GJ/hPreheatingAirandTailGas(350and500°C): 19.9 TOTAL: 754.7 GJ/h HeatAvailable: Intercoolinginthetwo-stageoxygencompression(277-25°C): 17.1 GJ/hCoolingthereformingproduct(1300-320°C): 170.0 GJ/hWGS(320-25°C): 422.3 GJ/hCoolingTailgasbeforePSA-2(450-25°C): 14.7 HeatfromburningTailGasandcoolingthefluegas(1000-100°C): 130.6 GJ/hTOTAL: 754.7 GJ/h Difference: 0.0 GJ/h

ATR:

Table47-HeatdemandandheatavailableinATR

Value UnitHeatDemands: PreheatingWater(320and350°C): 327.1 GJ/hPreheatinggasinputinGHR(400°C): 69.5 GJ/hPreheatingoxygen(250°C): 1.8 GJ/hGHR(700°C): 155.5 GJ/hCO2Absorption(115°C)

38: 318.0 GJ/hPreheatingAirandTailGas(350and500°C): 15.9 GJ/hTOTAL: 887.7 GJ/h HeatAvailable: Intercoolinginthetwo-stageoxygencompression(277-25°C): 15.5 GJ/hCoolingthereformingproduct(1000-320°C): 408.2 GJ/hWGS(320-25°C): 378.4 GJ/hCoolingTailgasbeforePSA-2(340-25°C): 14.3 BurningTailGasandcoolingthefluegas(1000-100°C): 98.1 GJ/hTOTAL: 914.4 GJ/h Difference: 26.7 GJ/h


107

CRE:

Table48-HeatdemandandheatavailableinCRE

Value UnitHeatDemands: PreheatingWater(320and350°C): 237.4 GJ/hPreheatinggasinputinGHR(400°C): 50.3 GJ/hPreheatingoxygen(250°C): 1.2 GJ/hGHR(700°C): 112.4 GJ/hCO2Absorption(115°C)

38: 229.3 GJ/hPreheatingAirandTailGas(350and500°C): 12.9 GJ/hTOTAL: 643.5 GJ/h HeatAvailable: Intercoolinginthetwo-stageoxygencompression(277-25°C): 11.0 GJ/hCoolingthereformingproduct(1000-320°C): 288.4 GJ/hWGS(320-25°C): 272.7 GJ/hCoolingTailgasbeforePSA-2(340-25°C): 10.5 BurningTailGasandcoolingthefluegas(1000-100°C): 82.8 GJ/hTOTAL: 665.5 GJ/h Difference: 22.0 GJ/h

ComponentModellingHYSYS

Thevaluesarebasedoninputfromthethesissupervisors,aswellasJosteinSoggeatStatoilandthe

paperofMariVoldsund[8].Allpressureslistedinthereportareabsolutepressures.

Inputs:

NaturalGas

Table49-NaturalGascompositionandproperties.MeanValuesfromHeidrungasfield[51]

Value UnitPressure: 50 BarTemperature: 50 °CComposition,Molefraction:CH4CO2

C2H6

C3H8

i-Butanen-Butanei-Pentann-Pentann-Hexanen-Heptanen-Octane

0.85320.02210.07050.02730.00550.00940.00270.00270.00180.00130.0004

108

N2 0.0033Air

Table50-Airdesignparameters

Value UnitPressure: 1.013 BarTemperature: 25 °CComposition,Molefraction:N2

O2

0.790.21

Water

Table51-Waterdesignparameters

Value UnitPressure: 1.013 BarTemperature: 25 °CComposition,Molefraction:H2O

1.0

Oxygen

Table52-Oxygendesignparameters

Value UnitPressure: 1.013 BarTemperature: 25 °CComposition,Molefraction:O2

1.0

HeatersandCoolers

Table53-HeatersandCoolersmodellingparameters

Value UnitPressuredrop: 25 kPaNozzleParameters:Diameter:Elevation(Base):Elevation(Ground):

0.0500

mmm

Heatloss: None Compressors,ExpandersandPumps

Compressors

Table54-Compressorsmodellingparameters

Value UnitAdiabaticefficiency: 75 PolytropicMethod: Schultz Operatingmode: Centrifugal

109

CurveInputOption: Single-MW NozzleParameters:Diameter:Elevation(Base):Elevation(Ground):

0.0500

mmm

FrictionLossFactor: 0.006 kg-m2/sInertiaModelingParameters:RotationalInertia:RadiusofGyration:Mass:

6.00.2150.0

kg-m2

mkg

Expanders

Table55-Expandersmodellingparameters

Value UnitAdiabaticefficiency: 75 CurveInputOption: SingleCurve NozzleParameters:Diameter:Elevation(Base):Elevation(Ground):

0.0500

mmm


6.00.2150.0

kg-m2

mkg

Pumps

Table56-Pumpsmodellingparameters

Value UnitAdiabaticefficiency: 75 NozzleParameters:Diameter:Elevation(Base):Elevation(Ground):

0.0500

mmm


0.50.150.0

kg-m2mkg

Reactors

GHR

Table57-GHRmodellingparameters

Value UnitTypeofReactor: GibbsReactor PressureDrop: 50 kPa

110

ReactorType: SpecifyEquilibriumReactions EquilibriumReactions: ]a + 5%a → ]a% + 5%

]5# + 5%a → ]a + 35%]%5~ + 25%a → 2]a + 55%]�5Ä + 35%a → 3]a + 75%N]#5f{ + 45%a → 4]a + 95%L]#5f{ + 45%a → 4]a + 95%N]|5f% + 55%a → 5]a + 115%L]|5f% + 55%a → 5]a + 115%L]~5f# + 65%a → 6]a + 135%L]Å5f~ + 75%a → 7]a + 155%L]Ä5fÄ + 85%a → 8]a + 175%

SolvingOptions:MaximumNumberofIterations:Tolerance:

1001.0e-007

NozzleParameters:Diameter:Elevation(Base):Elevation(Ground):

0.0500

mmm

Heatloss: None SMR

Table58-SMRmodellingparameters

Value UnitTypeofReactor: GibbsReactor PressureDrop: 50 kPaReactorType: SpecifyEquilibriumReactions EquilibriumReactions: ]a + 5%a → ]a% + 5%



1001.0e-007


0.0500

mmm

Heatloss: None

111

Furnace

Table59-Furnacemodellingparameters

Value UnitTypeofReactor: GibbsReactor PressureFlueGas: 1 atmReactorType: SpecifyEquilibriumReactions EquilibriumReactions: CO + 0.5a% → ]a%

5% + 0.5a% → 5%a]5# + 2a% → ]a% + 25%a

]%5~ + 3.5a% → 2]a% + 35%a]�5Ä + 5a% → 3]a% + 45%a

N]#5f{ + 6.5a% → 4]a% + 55%aL]#5f{ + 6.5a% → 4]a% + 55%aN]|5f% + 8a% → 5]a% + 65%aL]|5f% + 8a% → 5]a% + 65%aL]~5f# + 9.5a% → 6]a% + 75%aL]Å5f~ + 11a% → 7]a% + 85%aL]Ä5fÄ + 12.5a% → 8]a% + 95%a


1001.0e-007


0.0500

mmm

Heatloss: None

POX

Table60-POXmodellingparameters

Value UnitTypeofReactors: ConversionReactorandEquilibrium

Reactor

PressureDrop:ConversionReactor:EquilibriumReactor:

2525

kPakPa

Reactions: ConversionReactions:]5# + 1.5a% → ]a + 25%a]%5~ + 2.5a% → 2]a + 35%a]�5Ä + 3.5a% → 3]a + 45%aN]#5f{ + 4.5a% → 4]a + 55%aL]#5f{ + 4.5a% → 4]a + 55%aN]|5f% + 5.5a% → 5]a + 65%aL]|5f% + 5.5a% → 5]a + 65%aL]~5f# + 6.5a% → 6]a + 75%aL]Å5f~ + 8.5a% → 7]a + 85%aL]Ä5fÄ + 9.5a% → 8]a + 95%a

EquilibriumReactions:

]a + 5%a → ]a% + 5%

112



0.0500

mmm

Heatloss: None ATR

Table61-ATRmodellingparameters

Value UnitTypeofReactor: GibbsReactor PressureDrop: 50 kPaReactorType: SpecifyEquilibriumReactions EquilibriumReactions: ]a + 5%a → ]a% + 5%

]5# + 0.5a% → ]a + 25%]5# + 5%a → ]a + 35%

]%5~ + 25%a → 2]a + 55%]�5Ä + 35%a → 3]a + 75%N]#5f{ + 45%a → 4]a + 95%L]#5f{ + 45%a → 4]a + 95%N]|5f% + 55%a → 5]a + 115%L]|5f% + 55%a → 5]a + 115%L]~5f# + 65%a → 6]a + 135%L]Å5f~ + 75%a → 7]a + 155%L]Ä5fÄ + 85%a → 8]a + 175%

2]a → ]a% + C


1001.0e-007


0.0500

mmm

Heatloss: None WGS

Table62-WGSmodellingparameters

Value UnitTypeofReactor: EquilibriumReactors PressureDrop: 25 kPa

113

EquilibriumReactions: ]a + 5%a → ]a% + 5% NozzleParameters:Diameter:Elevation(Base):Elevation(Ground):

0.0500

mmm

Heatloss: None SeparatorsandPurification

Separators

Table63-Separatormodellingparameters

Value UnitHYSYSSeparatorType: Separator PressureDrop: 0 kPaGeometry: VerticalFlatCylinder NozzleParameters:Diameter:Elevation(Base):Elevation(Ground):

0.0500

mmm

Heatloss: None CO2Absorption

Table64-CO2Absorptionmodellingparameters

Value UnitHYSYSComponent: ComponentSplitter PressureDrop: 50 kPaRecoveryrate: 95 %mole-basisCO2Pressure: kPa

Splits:CH4H2

COCO2

H2OCC2H6

C3H8

i-Butanen-Butanei-Pentann-Pentann-Hexanen-Heptanen-OctaneN2

O2

CO2Absorbed:0000.950000000000000

PSAfeed:1110.051111111111111

Molebasis

114

PSA

Table65-PSAmodellingparameters

Value UnitHYSYSComponent: ComponentSplitter PressureDrophydrogen: 200 kPaRecoveryrate: 90 %

Pressuretailgas: 250 kPaSplits:CH4H2

COCO2

H2OCC2H6

C3H8

i-Butanen-Butanei-Pentann-Pentann-Hexanen-Heptanen-OctaneN2

O2

H2Adsorbed:00.9000000000000000

TailGas:10.1111111111111111

115

HYSYSModels:

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120

C. WindData39

Whencalculatingthewindpowersupplyfactor40inSection6.3,thesewinddataandthisMatlabscript

wasused.

WindDatatextfile(mnwind.txt):

Onlythefirst30of8058entriestotalisshowedinTable66.Itisinconvenienttoattachthewinddata

inthereportduetothelengthofthetextfile.Thetextfile(mnwind.txt)canbesentonrequest.

Table66-WinddatatextfileusedintheMatlabscript.Onlythefirst30of8058entriesisshowedinthetable.Thewinddataiscapturedoverayearat3differentlocationsinMid-Norway.

Datanumber Winddatalocation1[m/s] Winddatalocation2[m/s] Winddatalocation3[m/s]1: 1.0500000e+001 1.2100000e+001 6.8000000e+0002: 1.5900000e+001 1.4600000e+001 5.4000000e+0003: 1.5500000e+001 1.4700000e+001 8.6000000e+0004: 1.5600000e+001 1.4500000e+001 7.1000000e+0005: 1.3600000e+001 1.6300000e+001 8.0000000e+0006: 1.5700000e+001 1.5100000e+001 6.1000000e+0007: 1.7700000e+001 1.7900000e+001 6.5000000e+0008: 1.5400000e+001 1.5200000e+001 7.2000000e+0009: 1.5900000e+001 1.5500000e+001 6.6000000e+00010: 1.6000000e+001 1.4800000e+001 6.5000000e+00011: 1.5400000e+001 1.4100000e+001 6.6000000e+00012: 1.6300000e+001 1.3000000e+001 8.0000000e+00013: 1.5400000e+001 1.3900000e+001 7.4000000e+00014: 1.5800000e+001 1.3800000e+001 6.8000000e+00015: 1.6000000e+001 1.3600000e+001 7.4000000e+00016: 1.3400000e+001 8.6000000e+000 6.0000000e+00017: 1.2400000e+001 1.3000000e+001 6.7000000e+00018: 1.3500000e+001 1.3300000e+001 7.7000000e+00019: 1.3200000e+001 1.2600000e+001 7.3000000e+00020: 1.3600000e+001 1.3200000e+001 7.8000000e+00021: 1.3500000e+001 1.2400000e+001 7.4000000e+00022: 1.3600000e+001 1.2700000e+001 7.8000000e+00023: 1.4700000e+001 1.4900000e+001 7.7000000e+00024: 1.4600000e+001 1.3900000e+001 8.6000000e+00025: 1.4900000e+001 1.2900000e+001 1.0000000e-00126: 1.4200000e+001 1.4400000e+001 0.0000000e+00027: 1.4400000e+001 1.2700000e+001 8.3000000e+00028: 1.4800000e+001 1.1800000e+001 0.0000000e+00029: 1.3600000e+001 1.1200000e+001 0.0000000e+00030: 1.3700000e+001 1.0200000e+001 0.0000000e+000

39WinddataprovidedbyProfessorMagnusKorpås40Thewindpowersupplyfactoristhepowerdirectlysuppliedbythewindfarm,dividedbythetotalpowerdemandoftheelectrolysisplant.

121

MatlabScript(windproduction.m):

%Script for generating wind power production time series wspeed = load('mnwind.txt'); %Wind speed time series for three locations [Nsteps, Nsites] = size(wspeed); Pw_rat = [1 1 1]; %Installed wind power capacity wspeed_factor = [1 1 1]; %Multiplication factor for adjusting wind speed %Enercon E70 with storm control Power_Curve = [0 0;1 0;2 2;3 18;4 56;5 127;6 240;7 400;8 626;9 892; 10 1223;11 1590;12 1900;13 2080;14 2230;15 2300;25 2300;30 0;100 0]; Power_Curve(:,2)=Power_Curve(:,2)./max(Power_Curve(:,2)); % Normalised power curve %% Create wind power output for each time step for each wind site Pw = zeros(size(wspeed)); for i=1:Nsites Pw(:,i) = interp1(Power_Curve(:,1),Power_Curve(:,2),wspeed_factor(i)*wspeed(:,i)).*Pw_rat(i); end Pw(Pw<0)=0; WPSF = (1-sum(Pw(:,1)>0)/length(Pw(:,1))+1-sum(Pw(:,2)>0)/length(Pw(:,2))+1 sum(Pw(:,3)>0)/length(Pw(:,3)))/3;

Concepts for Large Scale Hydrogen Production - NTNU Open

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