LiquidHydrogenTechnologies2022WorkshopSummaryReportHydrogen&FuelCellTechnologiesOfficeU.S.DepartmentofEnergyMonthYear(FranklinGothic12pt)LIQUIDHYDROGENTECHNOLOGIESWORKSHOP–SUMMARYREPORT(Thispageintentionallyleftblank)2LIQUIDHYDROGENTECHNOLOGIESWORKSHOP–SUMMARYREPORTPrefacePreparedby:U.S.DepartmentofEnergy/OfficeofEnergyEfficiencyandRenewableEnergy/HydrogenandFuelCellTechnologiesOfficeincoordinationwiththeNationalAeronauticsandSpaceAdministration.3LIQUIDHYDROGENTECHNOLOGIESWORKSHOP–SUMMARYREPORTAcknowledgmentsTheHydrogenandFuelCellTechnologiesOffice(HFTO)andtheNationalAeronauticsandSpaceAdministration(NASA)wouldliketothankallthespeakerswhopresentedattheworkshop:•NedStetson–U.S.DepartmentofEnergy,HydrogenandFuelCellTechnologiesOffice•MichaelMeyer–NationalAeronauticsandSpaceAdministration•OrianeFarges–AirLiquide•RajaAmirthalingam–PlugPower•AmgadElgowainy–ArgonneNationalLaboratory•JacobLeachman–WashingtonStateUniversity•Jo-TsuLiao–ShellInternationalExplorationandProduction•AndyJacobson–CB&IStorageSolutions•IanNeeser–ChartIndustries•RajeshAhluwalia–ArgonneNationalLaboratory•GladysAnyenya–WabtecCorporation•RaviSubramanian–GardnerCryogenicsDepartmentofAirProducts&Chemicals•AngelaKrenn–NationalAeronauticsandSpaceAdministration•AaronHarris–TheHydrogenSafetyPanel•JoeRonevich–SandiaNationalLaboratoriesHFTOandNASAwouldalsoliketothankthemoderatorsandscribesthatassistedduringtheworkshop,andtheorganizingteamfortheireffortinplanningandexecutingtheworkshop.OrganizingTeam:NedStetson,HFTO;MichaelMeyer,NASA;MarkRichards,HFTO;NehaRustagi,HFTO;JeffreyFeller,NASA;AdamSwanger,NASA;PeterBradley,NIST;Asha-DeeCelestine,HFTO.LogisticsSupport:StaceyYoung,NorthboundSolutions;RudyGutierrez,NorthboundSolutions.ModeratorsandScribes:NedStetson,HFTO;AngelaMacedoAndrade,HFTO;AnneMarieEsposito,HFTO;MarkRichards,HFTO;MartinSulic,HFTO;RobertJohnson,NASA;ChristineWatson,HFTO;TomasGreen,HFTO;NehaRustagi,HFTO;NikkiaMcDonald,HFTO;Asha-DeeCelestine,HFTO;AdamSwanger,HFTO;PeterBradley,NIST;ZacTaie,HFTO;EricHeyboer,HFTO;McKenzieHubert,HFTO;MarikaWieliczko,HFTO;ZeniaGarcia,NASA;BrandonMarsell,NASA.Theorganizersthankallmeetingparticipantsforengaginginvaluablediscussionandprovidinginformativefeedback.4LIQUIDHYDROGENTECHNOLOGIESWORKSHOP–SUMMARYREPORTNomenclatureorListofAcronymsAIAAAmericanInstituteofAeronauticsandAstronauticsAIChEAmericanInstituteofChemicalEngineersANLArgonneNationalLaboratoryANSIAmericanNationalStandardsInstituteASMEAmericanSocietyofMechanicalEngineersBEVBatteryelectricvehicleBILBipartisanInfrastructureLawCAPEXCapitalexpenditureDOEU.S.DepartmentofEnergyEEREOfficeofEnergyEfficiencyandRenewableEnergyEUEuropeanUnionFCEVFuelcellelectricvehicleGREETTheGreenhouseGases,RegulatedEmissions,andEnergyUseinTechnologiesModelHDHeavy-dutyHDSAMHydrogenDeliveryScenarioAnalysisModelHFTOHydrogenandFuelCellTechnologiesOfficeIRASIntegratedrefrigerationandstorageISOInternationalOrganizationforStandardizationLNGLiquefiednaturalgasMDMedium-dutyMLVIMultilayervacuuminsulationMRHTMaximumratedholdingtimeNASANationalAeronauticsandSpaceAdministrationNERNormalevaporationrateNFPANationalFireProtectionAssociationNISTNationalInstituteofStandardsandTechnologyOPEXOperationalexpensesOSHAOccupationalSafetyandHealthAdministrationPPEPersonalprotectiveequipmentR&DResearchanddevelopment5LIQUIDHYDROGENTECHNOLOGIESWORKSHOP–SUMMARYREPORTRD&DResearch,development,anddemonstrationSCSSafetycodesandstandardsSECSpecificenergyconsumptionSOAState-of-the-artSTMDSpaceTechnologyMissionDirectorateTDTTechnicalDisciplineTeamtpdTonnesperday6LIQUIDHYDROGENTECHNOLOGIESWORKSHOP–SUMMARYREPORTExecutiveSummaryOnFebruary22-23,2022,theU.S.DepartmentofEnergy’s(DOE’s)HydrogenandFuelCellTechnologiesOffice(HFTO),withintheOfficeofEnergyEfficiencyandRenewableEnergy(EERE),andtheNationalAeronauticsandSpaceAdministration(NASA)CryogenicsTechnicalDisciplineTeamjointlyheldavirtualworkshopfocusedonliquidhydrogentechnologies.Theprimaryworkshopobjectivewastoaddressdevelopmentneedsforlow-cost,energy-efficient,scalable,andsafeliquidhydrogengeneration,dispensing,andenduse.Theworkshopincludeddiscussionofstate-of-the-arttechnologies,research,development,anddemonstration(RD&D)gaps,innovativeconcepts,safety,andanalysisactivities.Intotal,625attendeesparticipatedinthetwo-dayworkshop,withpresentations,paneldiscussions,andbreakoutsessionsoneachday.ThefirstdaywasfocusedonliquefactionandbeganwithopeningremarksfromHFTOandNASA,followedbypresentationsonthecurrentstate-of-the-art(SOA)forhydrogenliquefaction(AirLiquide),lessonslearnedforliquidhydrogen(PlugPower),innovativeapproachestoimprovingscalabilityandefficiency(ArgonneNationalLaboratory(ANL),WashingtonStateUniversity),andliquidhydrogeninemerginglarge-scalemarkets(Shell).Followingthepresentationsondayone,speakersparticipatedinapaneldiscussionandQ&Asession.Attendeesthensplitintothreebreakoutsessions:HydrogenLiquefaction,LiquidHydrogenDeliveryandDistribution,andEmergingApplicationsofLiquidHydrogen.Theseconddaywasfocusedonliquidhydrogenstorageandhandling,andfeaturedpresentationsonthecurrentstatusoftechnologiesforbulkliquidhydrogenstorage(CB&IStorageSolutions,ChartIndustries),liquidhydrogenformedium-andheavy-dutyvehicles(ANL,WabtecCorporation),liquidhydrogentransferanddeliverypractices(AirProducts,NASA-KennedySpaceCenter),safetyrequirements(HydrogenSafetyPanel),andmaterialsperformanceatliquidhydrogentemperatures(SandiaNationalLaboratories).Daytwo’sbreakoutsessionsweresplitintoLiquidHydrogenHandlingandLiquidHydrogenStoragegroups.Followingbreakoutsessionsoneachday,moderatorsdeliveredabriefreport-outonthekeydiscussionareascoveredintheirbreakoutsessions.KeyoutcomesoftheworkshopwereopenandproductivediscussionsbyparticipantsfromNASA,DOE,industry,andacademiaabouttheSOAofcurrenttechnologies,researchanddevelopment(R&D)needs,andoutliningthegapsincodesandstandardsforsafeuse.Thisalsoincludeddiscussionofhowfederalfundingcanbeusedtoboostcomponentdevelopmentfortheliquidhydrogenecosystem,andhowstandardscouldbefurtherdevelopedandcreatedtobeconsistentinternationally,aswellasdomestically.KeyrecommendationsincludedincreasedR&Deffortstoimprovehydrogenliquefactiontechnologies,aswellasstorageandcomponentmaterialsanddesigns.Updatedcodesandstandardsassociatedwithliquidhydrogendelivery,handling,andstoragewasalsohighlightedasanurgentfocusarea.ContinuedcollaborationbetweenDOEandNASA,aswellasotherfederalandstateentities,washighlyrecommended.Thefollowinghigh-levelsummaryprovidessomebackgroundrelatedtoliquidhydrogentechnologies,includingmanufacturers’andend-users’perspectives,summariesofdiscussions,feedback,andconclusionsfromtheworkshop.Thisreport,alongwiththedetailedagendaandpresentationmaterialscanbefoundat:https://www.energy.gov/eere/fuelcells/liquid-hydrogen-technologies-workshop.InformationandoutcomesfromotherHFTOhostedworkshopscanalsobefoundontheHFTOwebsiteathttps://www.energy.gov/eere/fuelcells/workshop-and-meeting-proceedings.7LIQUIDHYDROGENTECHNOLOGIESWORKSHOP–SUMMARYREPORTTableofContentsExecutiveSummary...........................................................................................................................................7ListofFigures.....................................................................................................................................................9ListofTables.......................................................................................................................................................91Introduction...............................................................................................................................................101.1BackgroundonLiquidHydrogen.................................................................................................102Presentations............................................................................................................................................122.1Liquefaction:CurrentStatusandRD&DNeeds..........................................................................132.1.1CurrentState-of-the-ArtofHydrogenLiquefaction..........................................................132.1.2ExperiencesandLessonsLearnedwithLiquidHydrogen.................................................142.1.3InnovativeApproachestoImproveScalabilityandEfficiency..........................................162.1.4LiquidHydrogeninEmergingLarge-ScaleMarkets.........................................................182.1.5HydrogenLiquefactionPanelDiscussionandQ&A.........................................................182.2LiquidHydrogenStorageandHandlingInfrastructure:CurrentStatusandRD&DNeeds.........192.2.1CurrentStatusofTechnologiesUsedforBulkStorageofLiquidHydrogen....................192.2.2PotentialBenefitsandChallengestoLiquidHydrogenforMD/HDvehicles...................212.2.3CurrentPracticestoTransferandDeliverLiquidHydrogen.............................................232.2.4SafetyRequirementsforLiquidHydrogenHandlingandRefueling.................................242.2.5MaterialsPerformanceatLiquidHydrogenTemperatures................................................263BreakoutSessions...................................................................................................................................283.1HydrogenLiquefaction.................................................................................................................283.2LiquidHydrogenDeliveryandDistribution.................................................................................293.3EmergingApplicationsofLiquidHydrogen................................................................................303.4LiquidHydrogenHandling...........................................................................................................313.5LiquidHydrogenStorage.............................................................................................................333.6BreakoutSessionReport-out........................................................................................................344ConclusionsandRecommendations....................................................................................................37References.......................................................................................................................................................38Appendix...........................................................................................................................................................398LIQUIDHYDROGENTECHNOLOGIESWORKSHOP–SUMMARYREPORTListofFiguresFigure1.H2@Scalevisiontoenabledecarbonizationacrossmultiplesectorsoftheeconomy……………….10ListofTablesTable1.Workshopspeakers,affiliations,andpresentationtitles………………………………………………12Table2.Breakoutsessiontopics,moderators,andscribes……………………………………………………..28Table3.Summaryofreportslidesproducedbybreakoutsessionmoderators………………………...……….349LIQUIDHYDROGENTECHNOLOGIESWORKSHOP–SUMMARYREPORT1IntroductionAspartoftheU.S.DepartmentofEnergy(DOE)HydrogenProgram,aprimaryobjectiveoftheOfficeofEnergyEfficiencyandRenewableEnergy’s(EERE’s)HydrogenandFuelCellTechnologiesOffice(HFTO)isadvancingthecurrentstateofhydrogen-basedtechnologies.TheNationalAeronauticsandSpaceAdministration(NASA)hasextensiveexperiencewithliquidhydrogen.Amongotheractivities,HFTOplansandsupportsworkshopsthatbringtogethermembersoftheresearchcommunityfromacademia,industry,andgovernmenttoidentifyanddiscusskeyaspectsofindividualcomponentswithintheoverallvisionforwide-scaleuseofhydrogen-basedtechnologies,aconceptreferredtoasH2@Scale.Onesuchaspectofthelargersystemisstorage,bothpriortotheenduseandasanintermediatemeansoftransporttoanultimatedestination.Inordertoaddressthecurrentstatusofliquidhydrogentechnologies,identifybarrierstofurtherdevelopmentandstrategiesforovercomingthem,andguidedirectionsandtargetsforfuturework,HFTOandNASAjointlyhostedtheLiquidHydrogenTechnologiesVirtualWorkshoponFebruary22-23,2022.Theworkshopincludedplenarysessions,expertpanelpresentations,andbreakoutsessions.ThisreportsummarizestheoutcomesandachievementsoftheworkshopthatwillprovideguidancetoHFTOandNASAindevelopmentoffutureactivitiesonliquidhydrogen.Figure1.H2@Scalevisiontoenabledecarbonizationacrossmultiplesectorsoftheeconomy.1.1BackgroundonLiquidHydrogenLiquefiedhydrogenhasamuchhigherdensitythancompressedgaseoushydrogen;71kg/m3forliquidhydrogenversus18kg/m3at250barand40kg/m3at700barforgaseoushydrogen.Thisincreaseddensityfacilitatesgreaterstoragecapacitywithinagivenvolume,allowingforlongerdrivingrangesandlargerpayloads.Thehigherdensityofliquidhydrogenstoragealsomeansthatrefuelingratesarefastercomparedtocompressedhydrogengas.Also,thelowerstoragepressuresmeanverystrongand/orheavytanks,typicallyusedforcompressedstorage,arenotrequired.Potentialapplicationsofliquidhydrogenincludeitsuseonboardheavy-dutyvehiclesandmarinevessels,atvehiclefuelingstations,andwithintheaerospaceindustry.Fordecades,NASAhasreliedonhydrogenasrocketfuelandhasdevelopedextensiveexperienceinsafeandeffectivehandlingofliquidhydrogen.However,thehardwareandprocessesforliquidhydrogenhasnotchangedmuchsincethe1960’s.Inefficiencieshaveledtomajorlossesofliquidhydrogenpurchasedduring10userid:73968,docid:140768,date:2023-09-18,sgpjbg.comLIQUIDHYDROGENTECHNOLOGIESWORKSHOP–SUMMARYREPORTthespaceshuttleprogram.Liquidhydrogenisacryogenthatposestechnicalchallengesbecauseofitsliquefactionandstorageatverylowtemperatures.Typically,hydrogenistransportedanddeliveredasaliquidwhenhigh-volumetransportisneededintheabsenceofpipelines.Toliquefyhydrogen,gaseoushydrogenmustbecooledtocryogenictemperaturesof20K(-253°C)orbelowthroughacomplex,multistepprocess.Usingtoday'stechnology,liquefactionconsumesanequivalentofmorethan30%oftheenergycontentoftheliquefiedhydrogenandisexpensive.Oncehydrogenisliquefieditcanbestoredattheliquefactionplantinlargeinsulatedtanks,knownasdewars.Someamountofthestoredliquidhydrogenwilltypicallybelostthroughevaporation,or“boil-off”,especiallywhenusingsmalltankswithlargesurface-to-volumeratios.Boil-offlossesduetoheattransferfromtheenvironmentareamajorconcernforlong-termstorageandcanbeasmuchas5%perday.Mitigationoftheselossesrequiresspecializedtankdesigns,incorporatingheatexchangersandinsulationsystems,whichcanalladdtothetotalsystemcost.Researchtoimproveliquefactiontechnology,liquidhydrogenstorage,aswellasimprovedeconomiesofscale,couldhelplowertheenergyrequiredandthetotalcost.Previously,HFTOincollaborationwithNASA,hostedthevirtualAdvancesinLiquidHydrogenStorageWorkshoponAugust18,2021.ThisworkshopcoveredDOE’sliquidhydrogenrelatedinitiativesandoutlook,andintroducedrecentadvancementsinlarge-scaleliquidhydrogenstoragetechnologiesandprojectsatNASA,includingintegrationofactiverefrigerationsystems,highperformanceinsulation,andtheconstructionofanext-generation1.25milliongallonliquidhydrogenstoragesphereattheKennedySpaceCenter.AttendeesincludedU.S.andinternationalstakeholdersfromindustry,academia,andgovernmentagencies.11LIQUIDHYDROGENTECHNOLOGIESWORKSHOP–SUMMARYREPORT2PresentationsTheLiquidHydrogenTechnologiesworkshopbeganwithopeningremarksandanoverviewoftheDOEHydrogenProgramfromNedStetson,HydrogenTechnologiesProgramManager,HFTO.HediscussedtheProgram’sgoalsandprioritiesonlow-cost,efficient,andsafehydrogenproduction,delivery,andstorage.HealsooutlinedtheHydrogenEnergyEarthshotInitiativeanddiscussedthehydrogenprovisionsintheBipartisanInfrastructureLaw(BIL)thatincludes$9.5BforcleanhydrogentechnologiesandthedevelopmentofaNationalHydrogenStrategyandRoadmap.Heconcludedwiththetopareastoidentifyneedsfortechnologydevelopmentandkeyconcernstodiscuss,whichincludedhydrogenliquefaction,large-scalemarkets,applicationsforliquidhydrogen,andinfrastructureforliquidhydrogenstorageandhandling.MichaelMeyer,NASACryogenicsTechnicalDisciplineTeamLeader,gaveanoverviewofNASA’sorganizationalstructureandsharedtheircurrentdevelopmentsandapplicationsforliquidhydrogen.HebeganbyoutliningthecryogenicactivityareasatNASAandtheoverallscopeofthecryogenicstechnicaldisciplineteam(TDT),whichincludesthermalconditioningforsensors,instruments,andhighefficiencyelectronicmotors;in-spacepropellantstorageandutilization;launchvehiclepropellant;andgroundtestingandoperations.HementionedthathydrogenhasbeenusedfordecadesbyNASA,andthatliquidhydrogeninaeronauticsevenpredatesNASA,suchasattheNACALewisField(nowNASA-GlennResearchCenter).Currently,NASAisdevelopinglaunchandgroundtestingsystemsemployingnewliquidhydrogenstoragevessels,includingaliquidhydrogenstoragespherewith4,732m3(1.25Mgallons)capacity.Thespacelaunchsystemrequires1,770m3ofliquidhydrogenand995m3ofliquidoxygen,andthefirstlaunchissettotakeplaceintheSpringof2022.HediscussedhowthecrewedMarsmissionorbitalmechanicsgenerallyrequirea2-3yearroundtrip,whichinvolvesaverylargeamountofpropulsiveenergythatwillneedareactor,liquidhydrogenpump,hydrogenheatexchanger,convergingexpandingnozzletogeneratethrust,liquidhydrogenstorage,largehabitatforcrew,andin-spaceassembly.HefinishedwithpresentingsomeofNASA’sstrategic/keyfacilitiesandassetsincryogenicsthatencompassawiderangeofsizes,types,andcapabilities.ThefollowingsectionssummarizethepresentationhighlightsandQ&Adiscussionfromtheworkshopsessions.SpeakerbiosandcopiesoftheirpresentationscanbefoundontheWorkshopProceedingswebpage:https://www.energy.gov/eere/fuelcells/liquid-hydrogen-technologies-workshopAnoverviewofthepresentationspeakersandtopicsispresentedinTable1.Table1.Workshopspeakers,affiliations,andpresentationtitles.SpeakerDayOnePresentationTitleOrianeFargesAffiliationState-of-the-ArtofHydrogenLiquefactionAirLiquideRajaAmirthalingamPlugPowerExperiencesandLessonsLearnedwithLiquidHydrogenAmgadElgowainyArgonneNationalLaboratoryOpportunitiesandChallengesofLiquidHydrogenSupplyChainJacobLeachmanWashingtonStateUniversityHydrogen:NovelLiquefiersforNovelMoleculesJo-TsuLiaoShellInternationalLiquidHydrogeninEmergingLarge-ScaleMarketsAndyJacobsonDayTwoCB&IStorageSolutionsLiquidHydrogenStorageTechnologies12LIQUIDHYDROGENTECHNOLOGIESWORKSHOP–SUMMARYREPORTIanNeeserChartIndustriesLiquidHydrogenBulkStorageIntroductionRajeshAhluwaliaGladysAnyenyaArgonneNationalLaboratoryOnboardLiquidHydrogenStorageforLongRaviSubramanianHaulTrucksAngelaKrennWabtecCorporationLiquidHydrogenforMedium-andHeavy-AaronHarrisDutyVehicles-WabtecOverviewJoeRonevichGardnerCryogenicsDepartmentCurrentPracticestoTransferandDeliverofAirProductsLiquidHydrogenNASA-KennedySpaceCenterNASAPerspectivesonTransferandDeliveryofLiquidHydrogenHydrogenSafetyPanelSafetyRequirementsforLiquidHydrogenSandiaNationalLaboratoriesFuelingMaterialsPerformanceatLiquidHydrogenTemperatures2.1Liquefaction:CurrentStatusandRD&DNeeds2.1.1CurrentState-of-the-ArtofHydrogenLiquefactionOrianeFarges,AirLiquideAirLiquideisaworldleaderingases,technologies,andservicesforindustryandhealthcare.OrianeFargesbeganbyhighlightingimportantpropertiesofhydrogen,includingflamevisibilityandtemperature,flammabilityranges,andexplosivelimits,asareminderoftheimportanceofsafety.Personalprotectiveequipment(PPE)andhydrogendetectionareimportantforanyhydrogenusecase.AirLiquideisinvolvedinallpartsofthehydrogenvaluechain,fromproductiontotransportationandfuelingstations,withliquefactionfallingwithinconditionandstoragestage.AirLiquidehasmanydevelopmentsindeepcryogenics(approximately-253°Candbelow)thatareonthecolderspectrum,whichincludeheliumandhydrogen.Fordeepcryogenicsofhydrogenandhelium,AirLiquidehasover20operatingunitsintheworld,withafewmoreunderconstruction.Theydevelopproprietarypurificationandliquefactionprocessesthatincludesolutionsforefficientliquidhydrogenboil-offmanagement,andinhouseproprietaryequipmentlikehydrogenturbines.Theyalsodesignandmanufacturetheirowncoldboxes.Theirexpertiseincryogenicsstemsfromtheirabilitytodesignandmanufacturetheirownprojectsandplants.ForAirLiquide’shydrogenliquefactionplants,thestate-of-the-artiscurrentlyinthemediumrangecapacityof30-50tonnesperday(tpd).Dependingonthesize,smallertomediumcapacity(1-50tpd)liquefactionplantstendtobemoreCAPEXoriented,whereaslargerplants(>50tpd)aremoreOPEXoriented.Overallefficiencyofthehydrogenliquefactionisalsoaffectedbyplantcapacity,with1-10tpdcapacityliquefactionplantshavinga>12kWh/kgefficiency,whileplantswithcapacitygreaterthan100tpdhaveabout6-7kWh/kgefficiency.Therefore,thetechnologyandcomponentsforhydrogenliquefactioncanvarydependingonthesizeoftheplant.Hydrogenliquefactionplantshaveaprecoolingandcoldpurificationprocessbeforetheliquefactionprocess.AccordingtoOrianeFarges,oneofthebottlenecksforexpansionofhydrogenliquefactionplantscapacityismachinery,whichincludescompressors.Italsorequiresimprovementofinsulationtechnology,andimprovementsinenergyefficiencyandrecovery.DuringtheQ&Asession,OrianeFargeswasaskedtodiscusstheoverallefficiencyforliquefaction,whichsheexplainedisheavilyaffectedbythehydrogenrefrigerationcycle.Whenitcomestoscalingdownforhydrogenliquefaction,shestatedthatitisquitedeveloped,andthatscalingupismoreofaconcern.Overall,efficiencyisstillbetterforlargerplants(6-7kWh/kg)thanforsmallerplants(12-15kWh/kg).13LIQUIDHYDROGENTECHNOLOGIESWORKSHOP–SUMMARYREPORTQ&AQuestion:Whatstepsaremostimportanttofocusonforimprovingoverallefficiencyforliquefactionofliquidhydrogen?Answer:Iwouldsaythatover60%oftheefficiencyisinthehydrogenrefrigerationcycle,sothisshouldbethefocus.Question:Lookingatscalingup(1000tpd)andscalingdown,whatwouldbethepotentialofscalingdown?Answer:Forscalingdown,itisnotmuchofaconcern.Wealreadyhavestandardunitsof1-2tpdthatareusingtheheliumcycle.Scaledownisnotaconcern.Whatwearetryingtofocusonisinscalingup.Question:Howdoestheefficiencyofsmallerplantscomparetolargerplants?Answer:Typically,forplantsof<5tpd,theefficiencyis12-15kWh/kg.Forplantswith>100tpd,it’s6-7kWh/kg.2.1.2ExperiencesandLessonsLearnedwithLiquidHydrogenRajaAmirthalingam,PlugPowerPlugPower,whereDr.AmirthalingamisaPrincipalR&DEngineer,isinvolvedinliquidhydrogenhandlingfromproductiontostorage,pumping,anddistribution.Importantaspectsforliquidhydrogenproductionareselectionofprecoolingandrefrigerationcycles,hydrogenpurification,catalystloadinginheatexchangers,andvendorselection.Forprecooling,havingimpuritiescanleadtomanyproblems,soitisimportanttohavepropertracingofimpuritiesintransferlines.PlugPoweralsostressedtheimportanceofhavingagoodrelationshipwithvendorstoimprovethedevelopmentofcost-effectiveequipmentforliquefaction.Considerationsforliquidhydrogenstorageincludethetypeofvessel(verticalorhorizontalcylindricaltanks,orspheres)andinsulatingmaterials(multilayervacuumjacketedorglassbeads),andmaterialsofconstruction(316Lvs304Lsteel).Glassbeadscanbeusedforcylindricaltanks,whichcanimproveperformanceby~40%,butthismightnotbesignificantwhenstoringliquidhydrogenforthelongterm.Forcontinuoususeofliquidhydrogen,mostofthesystemlossesareoutsidethetankandcanoccurduetonormalevaporationrate(NER),duringpumpingoperations,withtransferlineheatloss,orthroughblowdownlosses.Pumpcoolinglossesarealsorelevant,anditisnecessarytounderstandwhenandwhytheseoccurasthismayhappenwithvalvelossesassociatedwithcoolingorleaking.PlugPoweralsofocusesonthedevelopmentofmanufacturingliquidhydrogentransportationtankswithemphasisonimprovingpayload,NER,andmaximumratedholdingtime(MRHT).TheQ&AportionofRajaAmirthalingam’stalkwasquiteextensive.Someofthequestionsweregearedtowardslossesandknowingwheremostlossesoccurintheliquidhydrogenvaluechain.Tothis,Dr.Amirthalingamrespondedthatmajorlossesaremostlyonthetransferlinesandpump.Methodstoeliminatetheselossesarestillunderdevelopment,butonemajorobjectiveistopotentiallysub-coolliquidhydrogen.Theprocessofpurginglinesisdonebyusingnitrogen.Otherpointsdiscussedwerethatthedriverforincreasingto700barismainlyforuseinlargervehicles,andthatASMEcodesareusedforallofPlugPower’sstationarytanksandequipment.Boil-offismitigatedthroughrecovery,andoneofDr.Amirthalingam’smajorrecommendationswasthatDOEcouldfocusonliquidhydrogenequipment,whichwouldincludecryogenicpumps.Q&AQuestion:Whatwouldbethesystemlossforthewholesystem?Answer:Inweightpercent,I’mnotsosure.Youwasteliquidhydrogenwhenyoudon’thaveamethodologytorecirculateitback,whichyoucouldsave.Though,ifyoudon’thavearecirculationmethodattheend-usersitethelossescouldbeasmuchas30%.Question:Aremostofthelossesforyou,andyourendusers,onthetransfersandoutsidethestoragetank?14LIQUIDHYDROGENTECHNOLOGIESWORKSHOP–SUMMARYREPORTAnswer:Yes.It’salloverthelinestothepumps,alsointhetransferlines.It’smostlyonthetransferlinesandthepump.Question:Areyouinvestigatinghowtoimprovethetransferstoeliminatethelosses?Answer:There’salotofR&DworkbeingdonebyPlugPowertoreducethelosses.Oneofthemajorobjectivesistosub-cooltheliquidhydrogen.Howtosub-coolitistherealproblem.PlugPowerhasresearchfacilities,includingoneinRochester,totrytodevelopnewtechniquesandtestthemonsiteandinrealfuelingstations.Question:Howdoyoupurgethelines?Howdoyoupurgethesystemsyouuseonamediumlikehelium?Answer:Normally,inoperationswhenthesystemiscommissioned,themediausedforpurgingwouldbenitrogen.Question:What’sthedriverformovingfrom350barto700bar?Answer:Mainlyforlargervehicles,liketrucks.Morehydrogenneedstobeloaded,soitrequires700barforfilling.Question:Foryourtanksandequipment,whatcodesdoyouuse?IsitASMEforallstationarysystems?Answer:ItisASME.Yes,you’reright.Question:Fortheorthotoparaconversion,Iamassumingyou’reusingaparamagneticioncatalyst.Doyouseeanypotentialforimprovementsforcatalysts?Answer:Currently,thereisreallyonlyonemethodusedfororthotoparaconversion,butwhatwecanoptimizeisthelocationofthecatalyst.Thatcatalystiseitherintheheatexchangerorinaseparatevessel.Therearealotofsimulationsthatshowtheadvantagestohaveitintheheatexchanger.Itcouldalsobeindirectlyusedtooptimizetheutilizationofliquidhydrogenitself,sowehavealotofresearchintothoseaspects.Question:What’sthetypicaltimeoftransferofhydrogenfromthedeliverytrailertothelocalhydrogenstoragetank?Answer:Itdependsonthepressure.Howmuchpressureisinthetankandinthedownstreamtank,whichyoucanadjust,butusuallyittakesacouplehours.Question:Whatsortofguidancecanyouprovideonimprovementstotheliquidhydrogenpumpsandthetransfers?Answer:Essentially,itispumpmanufacturing,andit’samajortopicthesedays.Therearealotofmanufacturerscomingupwithgoodideasthatarebeingtested.However,themajorissueisthatinthemiddleofconstructionhowdoyoumeasurethesystem?Youalsowanttodowhatyoucantoreducethefrictionlosses.Ifeelliketheprogressthat’sgoingonwithdifferentvendorswillresultingoodpumps.Question:Forinsulationinliquidhydrogentanks,alotofthestandarddewarsusemultilayervacuuminsulation(MLVI),whereascircular(larger)tanksusematerialslikeglassbeads,perlite,etc.Canyouelaboratemoreoninsulation,andatwhichpointwoulditmakesensetoswitchfromMLVItoglassbeads,orothertypesofmaterials?Answer:Boil-offlossesarecommon,sowhateverMLVIyouuse,youcanincreaselayerstoimproveit.Butthemajorissueisholdingthevacuum,sothat’sanissuetoconsiderwhenchoosingamaterialforinsulation.Forglassbeads,accordingtovendors,lossesarereducedby40%.So,ifyouwanttostorehydrogenforalongtime,40%savingsisbig.However,whenthere’scontinuoususeofthetankforfueling,thelossesinthetransferlinesarehugecomparedtothosefromtank,sothe40%improvementbecomesinsignificant.Still,glassbeadsarenew,sowe’restillinvestigating.Question:Doyoudoanyboil-offrecovery?Answer:Yes,forourproductionplants,alltheboil-offisrecoveredandgoesbacktotheliquefactionplant.15LIQUIDHYDROGENTECHNOLOGIESWORKSHOP–SUMMARYREPORTQuestion:Howaboutincustomersites(e.g.,fuelingstations)?Answer:Inliquidhydrogenstations,ourworkisstillongoing,butwe’reultimatelyfocusingonmethodstosub-coolit.Question:Forfuelingvehicles(e.g.,forkliftandtrucks),whatarethenozzlestandardsthatyouuse?Answer:Idon’thavetheinfoforthat.Question:AnyrecommendationsonwhatareasoffocusforDOEtoimprovebothtechnologiesandprocesses?Answer:Developingagoodliquidhydrogenpump.Anyenergyspentondevelopingpumpsandcompressorsisgood.Forlow-flowpumpsandcompressors,leakageandlossarestillissues.Also,low-suctionpressurecompressorsarestilldeveloping,sofundingthistechnologywouldsignificantlyreducetheoverallsystemcost.Also,insulation.Iseepeopletalkingaboutusingprefabricatedpanelstoreducelosses.So,Iwonderifthedevelopmentofthesepanelsisbeingsupported,sowecanuseandtestthemtoseethevalueoftheirapplication.2.1.3InnovativeApproachestoImproveScalabilityandEfficiencyAmgadElgowainy,ArgonneNationalLaboratoryArgonneNationalLaboratory(ANL)isascienceandengineeringnationalresearchlaboratorythatisoperatedbyTheUniversityofChicagoandDOE.Dr.AmgadElgowainyleadstheElectrificationandInfrastructureGroupatANL.AspartoftheworkheleadsatANL,histeamworkswithmodelingsoftwareforanalysisonimprovingthescalabilityandefficiencyofhydrogenproductionanddelivery,specificallylookingintothetechno-economicsandenvironmentalimplicationsofhydrogen.TheanalyticaltoolsusedaredevelopedbyANLandincludethehydrogendeliveryscenarioanalysismodel(HDSAM)andthegreenhousegasses,regulatedemissions,andenergyuseintechnologiesmodel(GREET).HDSAMusesdatatodeliverpathways,componenttechnologies,andcostsofinteresttogovernmentagenciesandindustrystakeholders.UsingHDSAM,AmgadElgowainywentthroughthecostcontributionsthatwouldaffecthydrogenliquefaction,whichincludescostcontributionsofpipelinedelivery,tube-trailerdelivery,andliquidhydrogendelivery.Thecostofhydrogendeliveryandrefuelingforlight-dutyfuelcellelectricvehicles(FCEVs)wasshowntobestronglydrivenbyonboardrequirements.Overall,compressionandpumpingdominatedrefuelingcostforhighpressuretanks.TheenvironmentalimplicationfromGREETconsidershydrogenproductionmainlyfromnaturalgassteamreformationandgivescarbondioxide(CO2)emissionsfromClass6MDtrucks,andClass8day-cabandClass8sleeper-cabHDtrucks.Forliquefaction,thelife-cyclecriteriaofairpollutantemissionscanbesignificant.FromHDSAMandGREET,someoftheinformationincludesliquefierCAPEXandspecificenergyconsumption(SEC),whichsuggestthatSECcanpotentiallybeaslowas6kWh/kg.However,togettothoselowvaluesofSEC,havingasubstantialamountofgaseoushydrogendelivered(~120tpd)andamountsofliquefyinghydrogen(~130tpd)isimportant.Similarly,greenhouseemissionscouldbelowerathigheramountsofhydrogendeliveryandhydrogenliquefaction.Dr.Elgowainywasaskedquestionsregardinghydrogenpipelinesbeingbuiltwithoutmidlinecompressionorpumping,whichherespondedtobystatingthatpumpingmightincreaseoffloadtimeswithadditionalenergyforboil-offandreliquefaction.Whenitcametodiscusswhichofthefourareascouldbethemostoptimaltoimproveefficiency,Dr.Elgowainyansweredthatthisareaisregardingfundamentalresearch,whichisoftendoneinacademiainsteadofatthenationallablevel.Q&AQuestion:Cangaseoushydrogentransmissionpipelinesbebuiltwithoutmidlinecompression?Orliquidhydrogenlineswithoutpumping?Answer:Pumpingmightincreaseoffloadtimeswithadditionalenergyforboil-offgasre-liquefaction.16LIQUIDHYDROGENTECHNOLOGIESWORKSHOP–SUMMARYREPORTQuestion:Youmentionedthreenewconceptsandfourareaswheretheefficiencycouldbeimproved.Wherewouldyouinvest?Answer:Itneedstobefundamentalresearch,whichisnotfundedbyindustry,answeringquestionssuchas,“canwesievehydrogenthroughananotube?”and“canwemakeadiodethatfunctionsatcoldtemperatures?”JacobLeachman,WashingtonStateUniversityDr.JacobLeachmanisanassociateprofessoratWashingtonStateUniversitywherehisgroupisamajorplayerindevelopingnovelliquefiersforhydrogenapplications.Theylookathowtoimprovehydrogenliquefactionefficienciesbyunderstandinghowtousethefundamentalsofhydrogenandrefrigeration.Thefundamentalsofhydrogenincludethenovelhydrogenphysicsofquantumswellingandnuclearspinisomersandunderstandingideal-gaspropertyeffects.Hydrogenliquefierefficienciescouldbeimprovedbylookingatthefundamentalsofrefrigerationandunderstandinghowitcouldbechanged.Forrefrigeration,thereareonlyfourwaystochangeitsthermodynamiccycletooptimizehydrogenliquefaction,thisincludeschangingtheinputexergy,heattransferthroughentropy,worktransfer(enthalpy),andoutputexergy.Changingtheinputofliquefactionconsistsofincreasingtheexergyofthehydrogenflowingintothecycleviaelectrochemicalcompression,radiativecooling,orortho-paraseparation.Toimproveentropy,newmaterialsarebeingdevelopedtoallowforchangesinentropyatconstanttemperature,whilethewaystochangeenthalpyaredoneviaworktransferusuallymechanicalorelectricalwork.Finally,outputchangescouldconsistofcoldhydrogenwith0%orthoconversionat1.5atm.SomeoftheemergingconceptsWashingtonStateUniversityisworkingonincludequantumplumbing,ortho-paracatalyzedhydrogenregeneration,andcryogenichydrogendiodes.Forquantumplumbing,orthohydrogenpreferentiallyabsorbsonsurfacesandcanbeseparatedcreatingopportunitiesforquantumsievingortunnelingassistedcatalysis.Ortho-parahydrogenconversioncouldcounteractstackby-passbycreatinglocalizedexotherms.Also,soundspeeddifferencesbetweenorthoandparacouldpromotepara-migrationtowardscold.Lastly,cryogenichydrogendiodescouldbeusedandtunedto15meV,whichturnsortho-paraconversionheatintousefulelectricityandreducestheamountofheatliftrequiredfromanycycle.Overall,hydrogenhasuniquequantumopportunitiesforliquefiers.Severalquantumconceptshavethepotentialtoadvancenearlyallliquidhydrogencycles,butmorefundamentalresearcherisstillneeded.DuringtheQ&A,Dr.Leachmanwasaskedaboutliquefiers,operationalchallengesofscalingup,andatwhatpointcouldthefundamentalresearchinhydrogenandrefrigerationbenearcommercialization.Fordeterminingtheadvantagesofsmallervs.largerliquefiers,hestatedthatitisonacase-by-casebasis.Operationalchallengesareusuallyregardingtransferlossesandboil-offwithlargetanks,whichmightbemitigatedbyswappingtanksinsteadofre-fillingthem.Q&AQuestion:Whatistheadvantageofhavingalargernumberofsmallerliquefiersasopposedtolesslargeones?Answer1:Renewableenergyisinherentlydistributed,andliquefiersshouldmatchthatdistributedmodel.Answer2:We’llneedtofigureoutcryo-compressorswhichwillbenecessaryforpipelines,moreofwhichwouldbeneededforfewerliquefiers.Question:Whataretheoperationalchallengeswithscale-up,infrastructure,hazards,andsafetymanagement?Answer1:Operationalissuesincludeachievingtransfersquickly,minimizinglosses.Answer2:Regardingtransferlosses,therearelargeboil-offswithlargetanks.Whatifyouswaptankersinsteadofre-fillingtanks?Question:Whatisthetimetoreachpre-commercialscale?Answer:It’schallengingtodetermineduetopaperworkandstudies.Havingtherightteamintherightplaceisimportant.Fundamentalprogramsareneededratherthanappliedprograms.17LIQUIDHYDROGENTECHNOLOGIESWORKSHOP–SUMMARYREPORT2.1.4LiquidHydrogeninEmergingLarge-ScaleMarketsJo-TsuLiao,ShellInternationalJo-TsuLiaoisaSeniorEngineeratShellInternational,Inc.Shellhashadalotofexperienceinthedevelopmentofhydrogeninlarge-scalemarkets.Shellworksondevelopingandintegratingtechnologiesoftheliquidhydrogenvaluechaintoaddressthecostandscalechallengesassociatedwithhydrogenproduction,storage,transportation,distribution,andenergysystemintegration.Shell’sviewpointontheemergenceofinternationaldistributionisthattheyaredrivenbycostdifferentialforcleanhydrogenproduction,whichincludesrenewableresources,existinginfrastructure,naturalgasandcarbonstorageavailability,andland-useconstraints.IntheEuropeanUnion(EU),Korea,Japan,andpartsofChina,thedemandforhydrogenmaybemetmoreeffectivelybyimportingratherthanlocalproduction.Thisshowshowvitalanexpandingnetworkofhydrogentraderoutes,plans,andagreementscouldbe.Foremergingdemandsforhydrogen,itisexpectedtoreach$50Bby2027,andtheglobalhydrogen-poweredtransportmarketisexpectedtogrowfrom$2Bin2020to$20Bin2025.Forliquidhydrogenprojects,Shellaimstofurtherdevelopanintegratedsupplychain.Theyhavethefirstdemonstrationofacommercialscalehydrogenstoragetankdesignforinternationaltradeapplicationswiththeobjectivetodevelopafirst-of-its-kindaffordablelarge-scaleliquidhydrogenstoragetankforinternationalimportandexportapplications.Theprojectaimstodesignalarge-scaletankthatcanbeusedinrangesbetween20,000m3and100,000m3.Someofthekeysuccesscriteriaofthedesignareboil-offratesof0.01-0.1%perday,CAPEXbelow150%ofcomparableLNGstoragevessels,andmeetingtherequirementsofsafetyandintegrityregulatorybodies.Theirend-of-projectdeliverablesaretocompleteanaffordablelarge-scale(100,000m3)liquidhydrogenstoragetankdesign,buildliquidhydrogen-basedcryogenictestingapparatustomeasureinsulationthermalpropertiesdownto20K,andprovideatechnologydemonstrationthroughconstruction,start-up,andtestingofaprototypevessel,whichwouldultimatelyadvanceliquidhydrogenstoragetanktechnology.Q&AQuestion:Regardingtransportationgrowth,whatmarketswillbeinthebreakdown?Answer:Forallgrowthbetweennowand2027,theheavy-duty(HD)truckingsectorisbeingconsidered.Marineisalsothere,butthereisslowergrowthandit’snotforeseenby2027.Question:Whatkindoffuelformaritime,ammonia?Answer:Theyarewatchingthatmarket,butsafetyisaconcern.Question:Whatisthecostanalysisofammoniatoconverttohydrogen?Answer:Iftherequirementdoesn’trequirepurehydrogenanddirectinjection,thenitcouldbelesscostprohibitive.Purehydrogenwillcomewithacost.2.1.5HydrogenLiquefactionPanelDiscussionandQ&ASpeakersfromthefirstday’sLiquefactionsessionparticipatedinapaneldiscussionandQ&A,answeringquestionsposedbythesessionmoderatorandworkshopattendees.Question:Howtoaddressintermittencyissueswithrenewables?Answer1:Weneedenergystorageforhydrogen,ammonia,orothers.Answer2:Thesizingofstorage,downstreamelectrolyzerstobufferperturbationsarepossiblesolutions.Answer3:Thesecanbeaddressedbyusingelectrolyzersandhydrogenstorageatnight.Question:Whataffectsortho-paraconversionotherthantemperatureequilibrium?Answer:Thereisasmalldifference,butnegligible,inthenoiseofthefuelcell.Theremaybeopticalmethods(basicphysics).It’safundamentalsciencechallenge.18LIQUIDHYDROGENTECHNOLOGIESWORKSHOP–SUMMARYREPORTQuestion:Whenconvertingorthotopara,doesitconvertbacktonormalhydrogen?Answer:Theparaformneedsacatalystfortheconversiontoortho.Question:Willatankwithrecentlyconvertedgascontinuouslycool?Answer:Continuouscoolingwilldependontemperature.Question:Whataboutroomtemperature?Answer:Theexo/endothermforroomtemperatureisverysmall.Question:Canweuseisobarichydrogentoreducelosses?Answer:Thinfilmpolymersdon’tbreakinliquidnitrogen;maybefuelbladderswithhydrogen.NASAisfundingresearchonthis.Novelinsulationbarrierscouldalsobeused.Question:Whatscaleisneededtogetcostvalueforcentralizedat-scaleproduction?Answer:Asscaleincreases,thecostdecreases.We’llneedtooptimizeSEC.Asmallfarmiseasytoconverttoliquidhydrogen,butalargersizeisbetter.Question:Howsmallcanaliquefiergo?Answer:Perhapsdownto1tpd.Answer:Aliquefiercanbeassmallas0.25kg/day.There’savalleybetweenlargeandsmallliquefactionsystems.Currently,small-scalerefrigeratorshavepoorefficiencyandhighcosts.2.2LiquidHydrogenStorageandHandlingInfrastructure:CurrentStatusandRD&DNeeds2.2.1CurrentStatusofTechnologiesUsedforBulkStorageofLiquidHydrogenAndyJacobson,CB&IStorageSolutionsCB&IStorageSolutionsisalargeengineering,procurement,andconstructioncompany,specializinginprojectsforoil,gas,andnow,hydrogen.AndyJacobsondiscussedtherecentliquidhydrogenstoragetechnologydevelopmentbeingdonebyCB&I,whichincludesaliquidhydrogenstoragevesselatKennedySpaceCenterwithacapacityof1.25milliongallons(4,732m3).Currently,CB&IisemployingtwonewstoragetechnologiesdevelopedbyNASAthatprovidelarge-scaleliquidhydrogenstorageandcontrolcapability.CB&Iisusingnewtechnologyforinsulationoftheliquidhydrogenstoragevessels,whichincludesglassbubblethermalinsulation(evacuated).Anintegratedrefrigerationandstorage(IRAS)systemwillalsobeemployedtocoolthestoragegas/liquidandpreventboil-off.TheIRASheatexchangerwasdevelopedbyNASAanditprovidesactivethermalcontrolbytakingupheatthroughaninternalheatexchanger.Therefrigerantforthisprocessishelium,whichwillbefedthrough43metersofstainlesssteelcoilslocatedatthe25%and75%levelfills.Theglassbubbleinsulationsystemhasbeenanalyzedbyfillingtheannularspaceofthevesselwith3MK1glassbubbles.Itispredictedthattheglassbubbleswillshow40-100%betterperformancecomparedtoperlitewithrespecttoinsulation.Fieldtestingwitha190m3vacuum-jacketedliquidhydrogensphereatStennisSpaceCentergaveanaverageboil-offreductionof46%overthreethermalcyclesinsixyears.Foradvancingthestate-of-the-art,whichiscurrentlyataround40,000m3,thebasicdesignandconstructabilitystudycontinuestoprovideboil-offgashandlingsolutions,sendoutsystemssuchastruckloading,andinvitesdiscussionwithCB&Iontheneedsforlargercapacitytodeterminethebestoverallstoragesolution.IanNeeser,ChartIndustriesChartIndustriesisaglobalmanufacturerofcryogenicequipmentforliquidhydrogenproduction,delivery,andstorage.IanNeeserjoinedChartIndustriesin2013whereheiscurrentlyanewproductdevelopmentengineer.19LIQUIDHYDROGENTECHNOLOGIESWORKSHOP–SUMMARYREPORTHisresponsibilitiesincludethedesignandtestingofliquidhydrogenstoragesystemsfornewmarkets.Mr.Neeser’stalkfocusedonChart’sliquidhydrogenstoragetanksandtrailers.Chart’sliquidhydrogentanksaredoublewalledwithastainlesssteelinnerwallandcarbonsteelouterwallwhichprovidesexcellentductilityatlowtemperatures.Thesetankshavecapacitiesexceeding100,000gallonswithapproximately7%vaporspace.Thematerialselection,welding,andformingprocessesusedduringtankfabricationareallemployedtomitigatehydrogenembrittlement.Theinnervesselsupportsystemisthermallyoptimizedtoachievenegligiblethermalstressesbetweentheinnerandoutervessels.Bothanevacuatedannularspaceandradiationshieldingareusedforheatleakmitigation.Mr.Neeseralsodescribedthebasicpressuretransferoffloadstepswhichincludehosepurging,apressureramp,dispensingandsustainingpressure,filltermination,andfinally,hosepurging/emptying.Heliumisthebestoptionforapurgegas,butitisveryexpensive,sonitrogenistypicallyusedtopurgelargevessels.Hydrogencanalsobeusedtocyclepurgethehoses.Mr.NeeserprovidedmoredetailsaboutChart’sliquidhydrogentanksduringtheQ&Asessionfollowinghistalk.Inresponsetoaquestiononsloshbaffledesign,Mr.Neeserdescribedsloshbafflesasstainlesssteelplateswithafewfloworificesweldedtotheinsideoftheinnervessel,designedtodissipatethebulkkineticenergyofthetransportedliquid(e.g.,duringacceleration/braking).Whileitisagoodideatohavethem,thereactiveforcesinliquidhydrogentanksaretypicallylowerthanothercryogensandsloshbafflesmaynotbenecessary.Q&AQuestion:Canyousharemoredetailsonthe10,000lblimitforon-sitestorage(withouttriggeringadditionalOccupationalSafetyandHealthAdministration(OSHA)requirements)?Thisappliestogaseousstorage,also?Answer:The10,000lblimitappliestoOSHAProcessSafetyManagement(PSM).PSMhasabunchofadditionalregulatoryrequirements;over10,000lbson-sitestorageOSHA29CFR1910.119requiresaProcessSafetyManagement(PSM)program.IamnotasfamiliarwiththeOSHAspecificsonthat,buttomyknowledge,ifyourdesignedmaximumpayloadisunder10,000lbs,therequiredreportinglevelsaresignificantlyreduced/eliminated.Question:Isaluminumanacceptablealternativeto304/316stainlesssteel?Answer:AsfarasIknow,aluminumisnotanacceptablealternativetostainlesssteel,mainlybecauseofitsrelativelylowmeltingtemperature.Ifthetankwereinafire,itwouldbemorelikelytohavelossofcontainment,thusaddingmorefueltothefire.Question:Withhydrogenpermeationthroughsteel,doyouforeseeanyproblemwithlaminationontheoutercarbonsteelplate?Answer:Idonotforesee/havenotheardofanyissueswithdelaminationofthecarbonsteel.Question:Whataboutsloshbaffles?Answer:Forsloshbafflesonmobileunits,inmyopinion,itisstillagoodideatohavethem.However,duetothesignificantlylowdensityofhydrogenliquid,you'llfindthatthereactiveforcesaremuchlowerthanothercryogens.Question:Pleaseexplainsloshbaffledesign.Answer:Itisbasicallyastainlesssteelplatewithafewfloworificesweldedtotheinsideoftheinnervessel-designedtodissipatethebulkkineticenergyofthetransportedliquid(e.g.,duringacceleration/braking).Question:DoesChartofferaliquidnitrogen-cooledshieldforliquidhydrogentankslikeheliumtankersemploy?Answer:Chartdoesindeedofferliquidhydrogentankswithasacrificialliquidnitrogenshield.20LIQUIDHYDROGENTECHNOLOGIESWORKSHOP–SUMMARYREPORTQuestion:Whatisthethermalinducedstressontheinternalshellsupportingbracketsgiventhetemperaturedifferentialbetweentheinnerandoutershells?Answer:Wedesignourinnersupportsystemsverycarefullytoachievenegligiblethermalstressesbetweentheinnerandoutervessels.Thatis,wecalculatetheexpectedshrinkanddesignthesupportsystemgeometryto"takeupslack"incertainplaceswhentheinnertankgoesfromambienttemperature(duringfabrication)tocryogenictemperatures(inservice).2.2.2PotentialBenefitsandChallengestoLiquidHydrogenforMD/HDvehiclesRajeshAhluwalia,ArgonneNationalLaboratoryDr.RajeshAhluwaliaisaSeniorEngineerandthemanageroftheHydrogenandFuelCellSystemsSectionatArgonneNationalLaboratory.HisDOE-sponsoredanalysisprojectsfocusonfuelcells,hydrogenstorageandtransmission,andhydrogenproduction.Dr.Ahluwalia’stalkcoveredthedesignandanalysisofanonboardliquidhydrogenstoragesystemforheavy-dutytrucks.TheonboardliquidhydrogenstoragesystemwasdesignedforClass8trucksincludingsemi-trailers,refusetrucks,anddrayagetrucks.Specificmetricsincludedarangeof750miles,systemcapacityofmorethan60kgofhydrogen,gravimetriccapacityof15wt%,andavolumetriccapacityexceeding35g/L.Idealrefuelinganddischargerateswerealsostipulatedalongwithanoverallsystemcostof$8-9/kWh.Onceadutycycleforsemi-trailerlonghaultruckswasestablished,refuelingandpackagingoptionswerethenevaluated.Basedontheseconsiderations,threestoragesystemdesignswereanalyzed:1)systemwithanonboardpumpandalowpressureoffboardrefuelingpump;2)systemwithanonboardpumpandamediumpressureoffboardrefuelingpump;and3)systemwithoutanonboardpumpbutwithamediumpressureoffboardrefuelingpump.Structuralanalysesofthetanklinerandlinersupportwerealsoperformed.Dr.Ahluwaliapresentedtheperformanceresultsofeachsystemandcomparedthemtothegoalsoftheproject.Theinclusionoftheonboardpumpincreasedtheusablehydrogencapacityby19%.Thebestperformingsystemwasthesystemwiththeonboardpumpcoupledwithalowpressureoffboardrefuelingpump.Thegravimetriccapacityandvolumetriccapacitywere17.7wt%and37.1g/L,respectively.Theamountofhydrogenstoredonboardwas94.6kgandtherangebetweenrefuelingwasestimatedat621miles.Themaximumusablehydrogenwasapproximately82kgforatwo-tanksystemwhenullageandheelwereconsidered.OnequestionraisedduringtheQ&Afocusedonthermallyinducedstressesonthebracketsduetothedifferenceintemperaturebetweentheinnerandoutershell.Dr.Ahluwaliastatedthatheatleakagewasamainconcernsincethebracketsprovidedaheatleakpath.However,theiranalysiskeptthetotalheatgainto1W/m2,whichisachallengingcondition.Intheiranalysis,ANLdidnotconsiderthebracketstobeathermalcyclingconcernbecausetheonboardtankswouldberelativelylow-pressuresystems.Q&AQuestion:Whatisthethermalinducedstressonthebrackets,giventhedeltaT(changeintemperature)betweentheinnerandoutershells?Answer:Therearetwoconcernswhenusingbrackets,thefirstisheatleakage.ANLtriedtokeepthetotalheatgainto1W/m2whichischallenging,andthebracketsprovideaheatleakpath.ANLdoesnotconsiderthesebracketstobeathermalcyclingconcernbecausethesetanksarerelativelylow-pressuresystems.Thoughthermalcyclingmaynotbeimportantforon-designconditions,itmayneedtobeconsideredforoff-designconditionssuchaslettingthetankheatup.Question:CanyourestatethecapacityforliquidhydrogenonClass8trucks?Answer:ANLlookedatthreesystemsandthetotalamountofhydrogenstoragewasbetween85.2kgand94.6kg,howevernotallisusablebecauseofullageandheel.Themaximumusableliquidhydrogenwasabout82kgforatwo-tanksystem.21LIQUIDHYDROGENTECHNOLOGIESWORKSHOP–SUMMARYREPORTQuestion:Whatisthestatusofonboardcryopumps?Answer:Theseareneeded,criticaldevelopments.CriticaldesignspecificationsaredeltaP(changeinpressure)of4-5barandamaximumflowrateof17kg/hr.Dr.GladysAnyenya,WabtecCorporationWabtecCorporationisaprovideroffreightandtransitrailtechnologiesandservices.DrGladysAnyenyaistheengineeringleadforfuelcelldevelopmentatWabtecwheresheisresponsibleforthedesignanddevelopmentoffuelcellsystemsforlocomotiveandminingapplications.Dr.Anyenya’stalkfocusedonpotentialadoptionofliquidhydrogenforrailandfreightapplications.Wabtechasthefirst100%battery-electriclocomotiveworldwide,withacapacityof7MWh,andfuelandemissionssavingsof30%.Wabtec’sroadmaptocarbon-zerolocomotivesentailsmovingfromdiesel-electric(biodieselandrenewablediesel)locomotivestobattery-electricandthentohydrogenfuelcelllocomotivesby2030.Locomotiveshaveaggressivedutycycles(3,500-4,000MWh/yr,80%dailyuptimeand3,300kWratedpowerat17%usage).Theyalsooperateinextremeenvironmentalconditionswithtemperaturesrangingfrom-40toover120F,ataltitudesupto10,000ft.Thevolumeofliquidhydrogenrequiredforlocomotivesisapproximatelythreetimesthatofdieselforthesamerange.Liquefiednaturalgas(LNG)wouldbeaprecursortofulladoptionofliquidhydrogenonrails.ThelessonslearnedinLNGtenderdevelopmentarecriticaltosubsequenthydrogentenderdesigns.However,severalbarrierstohydrogenadoptionforrailmustfirstbeaddressed.Theseincludeonboardhydrogenstoragelimitationsforlongranges,refuelingtimeandestablishingrefuelingstationsalongtherailnetwork,rail’saggressivedutycycle,andhydrogensystemsafetyuncertainty.DuringtheQ&A,Dr.Anyenyaaddressedissuesofwheretheliquidhydrogenwouldbestored,onthelocomotiveorinatender.Thechoicewoulddependonthelocomotive’sapplication.Forapplicationswherethepowerrequirementsarelow,e.g.,shunterapplications,smallerfuelcellscouldbeusedonthelocomotiveallowingforhydrogenstorageonthelocomotiveitself.Linehaulapplications,however,wouldneedlargerfuelcellsandexcesshydrogenstorageand,therefore,atenderwouldbenecessary.Idealsolutionswouldbetovaporizethehydrogenbeforetransferringittothelocomotive.Typicalflowratesfora4MWfuelcelllocomotivewouldbe250kg/hrorhigher.Q&AQuestion:Howlikelyisitthatmostoftheliquidhydrogenisstoredonthelocomotiveandnotinatenderifwehaveconformabletanksavailable?Answer:Itwilldependontheapplicationofthelocomotive.Forexample,shunterapplicationsmaybeabletostoremostofthehydrogenonthelocomotivesincetheyhaverelativelylowpowerrequirements.Thelowerpowerrequirementsallowfordownsizingthefuelcellwhichfreesupmorevolumeforhydrogenstorageonthelocomotiveitself.However,forlinehaulapplicationsthefuelcellwillneedtobelarger(~6,000hp)whichmeanstherewon'tbeexcessvolumeforhydrogenstorage,andatenderwillbenecessary.Question:Thoughtsabouttheuseofammoniaasanalternativefuel?Answer:Ammoniamayalleviatesomeofthechallengeshydrogenpresents.Ammoniaisalreadytransportedviarailtoday,sosafetycodesandstandardsarealreadyinplace,alongwithammoniacarriercars.However,wewouldstillneedtodeveloptheammoniareformerandtransporthosesoverthecar/locomotivecoupler.Comment:Thelargevariationinenvironmentconditions(-40Fto120F,0to10,000ftaltitude)forrailapplicationshasalotincommonwithenvironmentvariationforaviationapplications.Comment:OntheLNGtendercarprojectmentionedinhertalk,thenaturalgasisvaporizedandfedtotheengine.22LIQUIDHYDROGENTECHNOLOGIESWORKSHOP–SUMMARYREPORTQuestion:Doyouproposetransferringtheliquidhydrogenfromthetendercartothelocomotive?Assumingthatthefuelcellisonthelocomotive.Answer:Theidealsolutionistovaporizethehydrogenbeforetransferringitoverthecouplertothelocomotive.Question:Whataretypicalflowratesofhydrogentopowertheseoperations(kgperhour)?Answer:Forexample,a4000kWfuelcelllocomotivewouldrequireabout250kg/hratratedpower.2.2.3CurrentPracticestoTransferandDeliverLiquidHydrogenRaviSubramanian,AirProductsGardnerCryogenicsDepartmentofAirProductsmanufacturescryogenictanksforthetransportationandstorageofliquidhydrogenandliquidhelium.RaviSubramaniancurrentlyhascommercialandtechnologyresponsibilitywithinGardnerCryogenicsdepartmenttodevelopandimplementstrategyfortheequipmentandenergybusinesseswithintheheliumandhydrogenmarkets.HistalkaddressedliquidhydrogenstorageanddeliveryoptionsprovidedbyGardner.Threemainoptionsforliquidhydrogendeliveryareviasemi-trailers,portabletanks,andInternationalOrganizationforStandardization(ISO)SwapBodytankcontainers.Liquidhydrogencanbestoredonsiteinhorizontal,liquidnitrogen-shieldedtanksforlongdurationstorage(upto33,000gallons)orincontainerizeddewars(11,000gallons).Otherstorageoptionsincludeportabletanks(10,000gallons)andsemi-trailers(upto18,100gallons).Eachtankusesacombinationofvacuumtechnology,multi-layerinsulationandthermalshieldingtominimizeboil-off.Thermalshieldingtechnologyofferslongerholdtimesenablinginternationaltransportationofliquidhydrogen.AngelaKrenn,NASANASAownstheworld’slargestliquidhydrogenstoragetanksat3200m3(850,000gallons)useablevolumeeach.In2019,constructionbeganonanadditionaltankwithstoragecapacityof4732m3(1.25milliongallons)ofliquidhydrogen.AngelaKrennisthePrincipalTechnologistforthermalmanagementsystemsinNASA’sSpaceTechnologyMissionDirectorate(STMD).Hertalkcoveredstandardpracticesforliquidhydrogentankloadingandmaintenance.TheliquidhydrogenstoragetankatKennedySpaceCenterwasbuiltinthe1960’s.Itisevacuatedandinsulatedwithperlite.Deliveryandtransferstepsincludeliquidhydrogentankeroffloadfromsupplier,systemleakcheckandsampling,andfinallyliquidhydrogenloadingtothelaunchpad.AllstepsintheprocessfollowthestandardpracticesasestablishedinOSHA1910.119,NFPA497andAIAA/ANSIG-095A-2017.Leakchecksarecommonduringtankeroffloadandareusuallyresolvedbycinchingthetransferhose.Flowoperationsduringthetransferofliquidhydrogenfromthemainstoragetanktothelaunchpadareperformedremotelyfromacontrolroomandthelaunchpadisfullyevacuatedduringtheliquidhydrogentransfer.ThetopicofliquidhydrogenpuritywasraisedduringtheQ&Asession.Purityisalwaysverifiedbeforeoffloadingfromthetankertrucksandmonitoredatseveralpointsinthesystem.Additionally,filtersareusedtomaintainthedesiredpuritylevelandthestoragetankissampledannually.Ms.Krennadvisedthoseconsideringthesafetyoflarge-scaleliquidhydrogenstoragetodedicatetimetotrainingtheirstaffonthesafetyprotocolsandguidelinesonsafelyhandlingliquidhydrogen.Q&AQuestion:Howdoyouverifythatthereislessthan1%oxygeninyourlineafterapurge?Answer:Severalportsinthesystemallowustomeasureoxygenlevelsatvariouspoints.Wealsousehand-heldmeters.Question:Duringfilling,doyouexperienceanypressuredrops?23LIQUIDHYDROGENTECHNOLOGIESWORKSHOP–SUMMARYREPORTAnswer:Wetypicallydon’tseedropsinpressureduringfillingsincewehavevaporizerstohelpcontrolthepressure.Question:Areyouconcernedaboutthepurityofliquidhydrogen?Answer:Yes,NASAisverysensitivetopurity.Wewouldalwaysdouble-checktankertruckmanifeststoverifythesourcebeforeoffloading.Wewouldalsosampleourstoragetanksannually.Wealsousedfilterstomaintainthedesiredpuritylevel.Question:IsNASAinvolvedwithHySTRA?Answer:Angelaisnotdirectlyinvolved.AdamSwangerwouldbebetterpreparedtoanswerthisquestion.Question:Forothersconsideringthesafetyoflarge-scalestorage,whattipscanNASAshare?Answer:Mostimportantly,takethetimetotrainyourstaffonthesafetyprotocols.Thereareestablishedguidelinesonhowtosafelyhandleliquidhydrogen.Solongasstaffaretrainedonthoseguidelines,largequantitiesofliquidhydrogencanbesafelystored.Question:Thatphotocontainedahydrogenvaporcloud?Whatwasthejustificationtoallowthisaspartoftheriskanalysis?Answer:Thephotoshowswatervapor,evidenceofhydrogenventing,nothydrogenitself.Severalthingsmadethisventingallowable,fromasafetyperspective.Ventingoccurredsignificantlyaboveoperatorheadlevel.Hydrogenislightandveryunlikelytomigratedownwardtooperatorlevel.Operatorshadhydrogenmetersonhandandregularlycheckedforhydrogenintheimmediatearea.Pre-plannedprocedureswereinplacetostopflowintheeventofhydrogendetectedintheimmediatearea.2.2.4SafetyRequirementsforLiquidHydrogenHandlingandRefuelingAaronHarris,HydrogenSafetyPanelTheHydrogenSafetyPanel’smaingoalistopromotethesafehandlingandenduseofhydrogensystems.AaronHarrisservesontheHydrogenSafetyPanelandisalsotheDirectorofOperationsandTechnologyforAirLiquideHydrogenEnergy.TheHydrogenSafetyPaneloperatesundertheCenterforHydrogenSafetyandprovidesreviewsandidentifiesmajorgapsinthe“safeoperation,handlinganduseofhydrogenandhydrogensystemsacrossallinstallationsandapplications”.Mr.Harris’discussionfocusedonchallengesassociatedwithsafeliquidhydrogenhandlingandstorageandthenecessarysafetycodesandstandardswhichmustbeimplemented.Earlystandardsforliquidhydrogenhandlingweredevelopedinthe1960’sforspaceapplications.Regulations,codesandstandardsforliquidhydrogentransfertovehiclestothisdate,however,donotexist.Also,inconsistenciesbetweenOSHAandNFPArequirementswhichnecessitatesite-specificunderstandingisachallenge.However,beforeupdatedstandardscanbedeveloped,thecommunityneedstounderstandif,andwhat,standardsareactuallyneeded.Inputfromequipmentmanufacturerswillalsobeimportant.SeveralquestionswereraisedduringtheQ&AsessionregardingNFPA2,theHydrogenTechnologiesCode.Thiscodeprovidessafetyprovisions“forthegeneration,installation,storage,piping,use,andhandlingofhydrogenincompressedgasformorcryogenicliquidform.”NFPAdocumentsaremodelcodeandmustbeadoptedbyastatefireagencyordelegatedbythestatetothemunicipalorcountylevelfireauthority.Themodelcodemaybeheavilyeditedinthatadoptionprocess,forexample,theNewYorkCityFireCode.CurrentconcernswithinthehydrogencommunityarefocusedonhowtomakeNFPA2moreefficientandbetteralignedwithrelatedISOandOSHAstandards.Mr.Harrisbelievesthatthereispotentialforfuturealignmentandcurrentdevelopmentsaremovinginthatdirection.However,globallyharmonizedstandardswillbedifficulttodevelopduetoeachnation’sdifferentrisktolerance.Instead,harmonizingacrossmarketsegmentsmaybepossible.Q&A24LIQUIDHYDROGENTECHNOLOGIESWORKSHOP–SUMMARYREPORTQuestion:HowdowegetNFPA2toaddresslargevolumeliquidhydrogenstorage?Answer:Whatwe’reconcernedaboutishowtomakethestandardefficient.There’sstillaproblemwithOSHAapprovingexistingliquidhydrogenstorage,sonotsurehowquicklyNFPA.HownecessaryisNFPA2guidanceifyoumayhavetoevaluateoncase-by-casebasis?Question:HowmuchofNFPA2isalignedtowhatisgoingoninISO/TC197?Answer:Alotofpotentialforfuturealignment,forfuturecapital-intensivealignment.It’sheadedtowardsalignment.Question:Anyexistingstandardsforliquefiers?Answer:Yes,theyarecommon.Intermsofmaterialsrequirements–thosemightbedesignspecific.Notgoingtoseedevelopmentofthatinthenear-term.Question:Isitunrealistictobringallcodes/standardsunderonecomprehensiveumbrella?Answer:Itdependsonthevisionattheendoftheday.We’renotgoingtohavegloballyharmonizedstandardsbecauseofdifferentrisktolerancesofeachnation.Forexample,thatdifferenceunderpinswhytherearedifferentsafedistances,etc.Itispossibletore-evaluatenationaltemplatesfrommid-2000stobetteraligncodesdevelopmentandstandardsdevelopmentorganizationstodefineownership.DOEcanmonitorthoseaffectedbyhydrogenandtheapplication.Aprocessofharmonizingacrossmarketsegmentscouldbepossible.Question:Isitpossibletohaveauniversalguideline?Answer:Notaloneinthinkingthat,butnotlikelybecausehumansdon’tbehavethesameinallapplications.Question:Howdoesthesafetypanelwork?Andhowdopeopleaccessresourcesfromthepanel?Answer:TheHydrogenSafetyPaneloperatesundertheCenterforHydrogenSafety.Panelmembersarefromacademia,industry,andconsultantswhohavebeenselectedtoparticipate.ThePanelprovidesreviewsandidentifiesmajorgapsintheapplicationsideofsafety.It’snotinvolvedinR&Dofbehaviorsofmaterials.ThePanelcancontracttoreviewDOEandCECprojects,aswellasindividualindustrialprojects.Question:DoesNFPA2enumeratethevariousjurisdictions'documentsthatneedtobeaddressed,anddoesitsupersedeallpriorNFPAcodes(NFPA55andNFPA50Aand50B)inrelationtocompliance?Answer:RegardingNFPA2supersedingothercodedocument:NFPAdocumentsaremodelcodeandmustbeadoptedbyastatefireagencyordelegatedbythestatetothemunicipalorcountylevelfireauthority.Themodelcodemaybeheavilyeditedinthatadoptionprocess,example:NewYorkCityFireCode.ThereisanopendiscussionbetweenNFPA2andNFPA55aseacharetheprimarycodeforvariousinstallationsdependingonthelocationandinstallationdate.Question:Isitpossibleorrealistictotryandbringallthehydrogen-relatedcodes&standardsunderone,comprehensiveumbrella?Atleastago-toplacethatsummarizesthemallformorestreamlined,practicaluse.Answer:Thereisasearchabledatabaseofhydrogencodes&standardshere:https://h2tools.org/codes-standards.Forcomprehensive"umbrella"guidance-Irecommendstartingathttps://h2tools.org/.OneoftheuniqueaspectsoftheU.S.isourpermittingprocess.Thereare17,000independentfirejurisdictionsintheU.S.Mostothercountrieshavefederalfirecodeswithverylittlelocalvariation.Irecommend"ReachingtheU.S.FireServicewithHydrogenSafetyInformation:ARoadmap"-NFPAreport2009-https://www.nfpa.org/News-and-Research/Data-research-and-tools/Emergency-Responders/Archived-reports---Emergency-responders.Question:Anythoughtsaboutaircraftfuelingin3500kgliquidhydrogenamountsperflight(737,aboutthreehoursofflight)?Answer:Regardingaircraftfueling,ifyouwanttodevelopastandardaroundaircraftfueling,theprocesscouldbesimilar.Youwouldwanttofirstdevelopthetargetfuelingperformance,duration,acceptableboil-offloss,25LIQUIDHYDROGENTECHNOLOGIESWORKSHOP–SUMMARYREPORTone-wayortwo-waytransfer,activeorpassiveprocesscontrols,etc.Thenyouwoulddevelopaconsensusprocessthroughdemonstration.2.2.5MaterialsPerformanceatLiquidHydrogenTemperaturesJoeRonevich,SandiaNationalLaboratoriesDr.JoeRonevichisaPrincipalMemberoftheTechnicalStaffatSandiaNationalLaboratoriesandworksintheHydrogenEffectsonMaterialsLaboratory.Inhistalk,hediscussedtheeffectsofliquidhydrogenandcryogenictemperaturesoncomponentmaterialproperties.Hydrogenembrittlementoccursinmaterialsundertheinfluenceofstresswhileinahydrogenenvironment.Theembrittlementprocessentailshydrogenfirstdissociatingonthemetalsurfacethendissolvingintothemetallatticeanddiffusingintoregionsoftensilestress.Whilehydrogenembrittlementisaconcerninallenvironments,higherpressuresandcyclingratestendtoresultinfastermaterialdegradation.Conventionalcryogenicmaterialsusedforliquidhydrogenapplicationsinclude3XXseriesausteniticstainlesssteelandaluminumalloys.The3XXstainlesssteelspossesshightoughness,highductility,andgoodperformanceinhydrogenenvironments.Thealuminumalloysexhibitlowsensitivitytohydrogenandnoductiletobrittletransitiontemperatures.Aluminumalloysaregoodoptionswhenweightreductioniscritical.Alloys,however,requirehightoughnessatcryogenictemperatures(20K).Whilehydrogendiffusionintothesematerialsisimportant,diffusionkineticsat20Ktendtobeslowascryogenictemperaturesgreatlylimithydrogendiffusion.Thehydrogeneffectat20Kisnodifferentthantheimpactofheliumatthesametemperature.Atlowtemperatures,however,ductilityissignificantlyaffectedbythepresenceofhydrogen,andthiscanleadtomaterialcracking.Dr.Ronevichidentifiedtheneedtocharacterizematerialbehaviorafterlongtermexposuretohydrogenatcryogenictemperaturesandexaminematerialresponseduringslowratefracturetestingastherearenotablegapsinthescientificliterature.DuringtheQ&Asession,Dr.Ronevichalsodiscussedhydrogenpre-chargingwhichreferstoplacingthespecimeninthepresenceofhydrogenforaspanoftimeathightemperatureandpressureandincreasedstresslevels.Thisisdonetoencouragehydrogentochargeintothematerialandpre-chargedspecimenscanthenbeusedtostudythelong-termeffectsofhydrogen.Novelmaterialsforhydrogenapplicationswerealsodiscussed.Theseincludealuminumalloys,Nitronicalloys,titaniumalloys,andcompositesbuttheiradoptionwoulddependoncostandavailablemarkets.Q&AQuestion:WhatisH-precharged?Answer1:Itisdifficulttogethydrogentogointostainlesssteelatroomtemperature.So,theywillheatupthematerialinapressurevesselwithhydrogenandthenpre-exposeittohydrogentopre-loadthehydrogencontent,whichcanthenbeusedtostudylongtermeffects.Answer2:Prechargingreferstoplacingthespecimeninthepresenceofhydrogenforaspanoftime(highertemperature,highpressure,increasedstresslevels)toencouragehydrogentochargeintothematerial.Question:Underwhatconditionsishydrogenembrittlementaconcern?Answer:Higherpressure,highercycleswilltendtocausefasterdegradation.Butitisaconcernforreallyallenvironments.Question:Doyouhaveopinionsonnovelmaterialsforliquidhydrogenstorage?Answer:Historically,300seriesstainlesssteelwasthepredominantalloybecauseithasworked(goodforstationaryapplications).Aluminumalloys,Nitronicalloys,andcompositeshavepotential,butit’snotclearifthereisamarketthere(willdependoncosts).Question:Thecostoftitaniumiscompetitive,whatisyouropinion?26LIQUIDHYDROGENTECHNOLOGIESWORKSHOP–SUMMARYREPORTAnswer:Weexposedtitaniumtohydrogenandstress…itturnedtopowder(becauseithydrided),butthebehaviorwilldependonthealloy.27LIQUIDHYDROGENTECHNOLOGIESWORKSHOP–SUMMARYREPORT3BreakoutSessionsOneachday,attendeesweredividedintobreakoutsessionsfollowingthespeakerpresentations.ThetopicsforDayOnewerehydrogenliquefaction,liquidhydrogendeliveryanddistribution,andemergingapplicationsofliquidhydrogen.OnDayTwo,attendeesweresplitintofourgroups,twoeachinthetopicareasofliquidhydrogenhandlingandliquidhydrogenstorage,tobetterfacilitatediscussions.Breakoutsessionswere40minuteslongonbothdays.Asummaryofthebreakoutsessiontopics,aswellasthemoderator(s)andscribesforeachsessionareshowninTable2.Table2.Breakoutsessiontopics,moderators,andscribes.DayOneSessionTopicModeratorScribesHydrogenLiquefactionRobertJohnsonAngelaMacedoAndradeMarkRichardsMartinSulicLiquidHydrogenDeliveryandNehaRustagiChristineWatsonDistributionTomasGreenEmergingApplicationsofLiquidDayTwoHydrogenNikkiaMcDonaldAnneMarieEspositoSessionTopicModeratorsScribesLiquidHydrogenHandling#1MarkRichardsChristineWatsonLiquidHydrogenHandling#2Asha-DeeCelestineEricHeyboerLiquidHydrogenStorage#1LiquidHydrogenStorage#2AdamSwangerAnneMarieEspositoMarikaWieliczkoTomasGreenNehaRustagiNikkiaMcDonaldZeniaGarciaMartinSulicBrandonMarsellMcKenzieHubertRobertJohnsonZacTaie3.1HydrogenLiquefactionWiththeguidanceofthemoderator,attendeeswereaskedtoconsiderfourmaintopicsofhydrogenliquefaction,whichincludedlimitationsofconventionalliquefactionpathways,novelapproachestoliquefactionandassociatedtechnologyreadiness,liquefactionneedsfordifferentscales,andsafetycodesandstandards.1.Limitationsofconventionalliquefactionpathways.Generally,thereisstillalotofR&Dneededtobringcostsdowninallaspectsoftheliquefactioncycle.Also,consideringanddevelopingfundamentalapproachestoimproveliquefactionareneeded.Glassbeadsmightbeconsideredviablesolutionsforinsulation;however,fundingisstillneededtoexplorethemasanoption.Managingboil-offisanotherlimitingfactor,whichNASAtriestomitigatebychangingthepositionoftheheatexchangertotheliquidportionofthetankandthenusinginternalcoilstocool.Theset-upisdifferentforlargertanksthatonlyhaveacoolantloop.Still,fundingwouldbeneededforaportablerefrigeratortocooldownthetanktoliquidhydrogentemperatures.28LIQUIDHYDROGENTECHNOLOGIESWORKSHOP–SUMMARYREPORT2.Novelapproachestoliquefactionandassociatedtechnologyreadiness.Somenovelapproachesforliquefactionincludeusingmixedrefrigerants,magneticrefrigeration,alongwiththeuseofglassbeadsforinsulation.Forglassbeads,thereispotentialbenefitsforliquidhydrogenstorageandforimprovinginsulation.Recently,glassbeadshavebeenusedwithavacuum,andhavebeenusedatsmallerscales.NASAhasusedthemfor50,000gallonsofliquidhydrogen,butiftheywouldbeusedforlargercapacityitwillbedifficulttopullthevacuumrequiredforthatapplication.Variabilitywithusingrenewablepowerisanissue,addinganenergystoragebuffer(e.g.,fuelcells)togenerateelectricityisstillconsideredanoptionforfutureapplicationsthatneeddevelopment.3.Liquefactionneedsfordifferentscales.Forliquefactionneedsatdifferentscales,typically,thesmallerscalesarelessefficientbecausethereishighercost/kgforliquefactionandstorage.However,smallscaleisstillnecessaryforsomeapplications,especiallywhenconsideringend-userneedstodeterminethebestsystem.Therefore,thescalesneededforliquefactionshouldbedeterminedonacase-by-casebasis.Otherconsiderationsfordifferentscalesarethecapacitiesofdifferenttypesoftanks,andthedifferencesandadvantagesofhorizontalvs.sphericaltanks.Generally,sphericaltankshavebettersurfaceareatovolumeatlargersizes,butifyouareconsideringasmallersizedtankthenahorizontaltankwouldbeabetteroption.Thereareissueswithtransportationifthetankistoobig,especiallywithlargersphericaltanks.Thisisoneofthereasonssphericaltanksaretypicallymanufacturedinthefield.Whenconsideringenergyefficiencyandpowerrequirementsofliquefaction,thepowerneededforhydrogenliquefactionis9-12kWh/day,butwithnewtechnologicaldevelopmentsitcanbebroughtdownto6-7kWh/day.Someofthesedevelopmentsincludeusingdifferentrefrigerantcyclesandcoolingmethodstohelpimproveenergyefficiency.Hydrogenliquefactionof6-7tpdisreasonable,butifyouwanttogosmallerthenitwillbemoreexpensive.Therefore,itcomesdowntoconsideringthetradeoffbetweenCAPEXandOPEX.Whenconsideringwhataretheliquefactioncapacitiesneededtodisplacecurrentfuelslikediesel,therearecurrentlynotargetsorscalesatthosecapacities.4.Safetycodesandstandardsforhydrogenliquefaction.Liquefactionofhydrogenisnotnew,NASAhasbeenworkingwithitfordecades,sotherearesafetycodesandstandards(SCS)thathavebeendeveloped.However,therearestillsomegapsandobstacleswhereSCSneedtocatchup.Thisisespeciallytrueforsub-cooledliquidswheretherehasbeenlimiteddevelopment.Apossiblesolutionwouldbegettingincontactwithothersthatarehandlingsub-cooledliquids(e.g.,SpaceX)thatmighthaveinformationontheSCSusedforsub-cooledliquidsandexplosivemixtures.Inaddition,sub-coolingbelowatmosphericpressure(~1/10to1/25psi)requiressafetyforoperatingatthosepressures,andforpressurizingthetanktothenfeedtheliquidtothevehicle.Currently,therearelimitedornocodesavailableforsub-cooledliquids.3.2LiquidHydrogenDeliveryandDistributionWiththeguidanceofthemoderator,attendeeswereaskedtoconsiderthreemaindiscussiontopicsrelatedtoliquidhydrogendeliveryanddistribution.1.Limitationsofcurrentdeliveryanddistributionpathways.Thegroupdiscussedthestatusoffiltrationfordistribution,wherepotentialcontaminantscomefrom,andhowtheyaredealtwith.Becausehydrogenmustbepuretoliquefy,theoperationofliquefactionitselfimpliespurification.Contaminantscanbeintroducedfromcomponentsusedduringhandlingoftheliquefiedhydrogen.NASAusesMIL-PRF-27201whichisthemilitaryspecificationforliquidhydrogen.This29LIQUIDHYDROGENTECHNOLOGIESWORKSHOP–SUMMARYREPORTspecificationrequiresfilteruseandlimitsthenumberofproducers,becausemostproducersdonotusefilterstoavoidaddedpressureandkeepthetemperaturelow.Particulatemattercanbeintroducedthroughoutthesystemsandvalves.Themilitaryspecificationdoesnotprovideanyaddedbenefitsincethefilteringonlyoccursonceandnotlaterwhenparticulatesmaybeintroduced.Inanycase,mostproductsarenotgoingtothemilitary.Somegroups,suchasminingandaviation,requirehighervolumes,e.g.,largeequipmentrequire1000kg/day,500-700kgatatime,andquickdistribution.Achievinganefficientandfastfillisimportant.Cryogenicstorageonboardvehiclesischallengingtoo,e.g.,ifyouneed>50kg/minfuelingofvehicleswithcryogenicstorage.Gasisverychallengingtostoreonvehicles,andthetransferrateusinggasistoolowforsomevehicles.Some,suchasvehiclesusedinmining,mayneedtotransferfuelin~20minutes.Railandferriesalsohavelargeliquidhydrogenrequirementsbutmaynothavethesametimeconstraints.HDvehiclescouldusegaseousorliquidhydrogenonboard,buthighercapacitiesmakemoresensetohaveliquid,asthishelpswithtransferrate.Foraircraft,turn-aroundtimeforaplaneisamajorconstraint.Thiswouldrequireavolumeofaround40,000Ltorefuelasmallerplanein15-20minutes,and>160,000Lforalargerplanein30-40minutes.Hightransferratescanbemanagedwellusingbayonetconnectors,whichallowupto100kg/mindependingonthepressuredifferential.With2,000kgofhydrogenatthegate,youcanrefuelin20minutes.Butamajorchallengeisstillgettingthefueltothegate.2.Novelapproachestodeliveryanddistributionandassociatedtechnologyreadiness.Thegroupdiscussedanalternativeapproachofusingswappabletanks,similartoexchangeablepropanetanks.Awell-designed,standardtankwouldbekey.Leavingtheentiretraileratthestationorswappingtheentiretankcouldbeidealfortrains,andheavy-dutyendusesthathaveverylargescales.Loadingastationarytankcouldtakemoretimeinsomecasesthanrefuelingatank.Therearechallengesinstandardizationforloadingbaysandconnections.ThosewithLNGexperiencefacesimilarproblems.Formarineandheavy-haultruckapplications,itisnotthesameas"colddiesel"fuel,becauseflammability,safety,andotherrisksaredifferent.Theideaofswappingcontainersinsteadofrefuelinginfrastructurehassomemerit.ASTMdidsomeworkonthis.Drydisconnectscansealsystemsothatlinesdonothavetobepurgedeachtime.UniversalHydrogenmakesmodulartanksthatareloadedandunloadedoffanaircraft.3.Safetycodesandstandardsforliquidhydrogendeliveryanddistribution.LiquidhydrogentanksareclosetobeingstandardizedinthejointSAEAerospaceStandards&EUactivity.Regardingtheliquidhydrogennozzle,WaltherPraezisionworkedtogetherwithBMWtocreateahoseandnozzleforliquidhydrogenfueling.ThiswasabouttobestandardizedatSAEJ2600whenBMWdroppedtheprogramforgaseoushydrogen.Thismeansthatmuchoftheworkiseitherverymatureand/orexistinghardwareispossible.ThereisanewforumcalledH2-AeroTeamthatisworkingwithSAAerospaceonstandardizingprocessesforEuropeans,andpeoplewereencouragedtojoinfutureseminarsandlearnmore.ThequestionofmanagingtransferoperationwithrespecttoPPEstandardsremains.3.3EmergingApplicationsofLiquidHydrogenWiththeguidanceofthemoderator,attendeeswereaskedtoconsiderfivemaindiscussiontopicswithregardstoemergingapplicationsofliquidhydrogen.1.Emergingapplicationsforhydrogenthatarelikelytorequiredeliveryinliquidform.Theaviationsectorisoneofthekeyareasthatwilllikelyrequireliquidhydrogendeliveryasitcanprovidethepower-to-weightdensitiesthatareneeded.Liquidhydrogenwillenablebothshortandmediumhaulflights.Thereisalsothepossibilityofusingliquidhydrogenforultra-long-haulflightsduetothelighterweightofthe30LIQUIDHYDROGENTECHNOLOGIESWORKSHOP–SUMMARYREPORTfuel,butlargeraircraftswillberequiredtomakethispossible.Optionsincludesuperconductingpropulsion,fuelcellsandcombustion,withcombustionasthefirsttechnologyexpectedtobeimplementedbetween2030and2035.Otheremergingapplicationsincludefuelcellbuses,trucks,andfarmequipmentwhichwouldentailhighusage.Themaritimesectorisalsopoisedtoadoptliquidhydrogenwhichcanbeusedtopowerlongrangeshipsandpassengerferries.Liquidhydrogencanalsobeusedforgridbalancingandforbackuppowerapplications.2.Associatedregionsofemergingapplications.LiquidhydrogenadoptionintheaviationindustryisbeingledbyteamsintheU.K.andEurope.Rolloutofliquidhydrogenfueledbuses,trucks,farmequipment,etc.isfocusedwithintheU.S.,whileNorwayisleadingthewayintheapplicationofliquidhydrogenforpassengerferries.3.Timelinesandscalerequirementsforadoptioninemergingapplications.Liquidhydrogenfueledtrucksarealreadyindevelopmentandthefirsttrucksshouldbereadythisyear,2022.Maritimedeploymentisexpectedintwotothreeyears,whilethetimelineforfulldeploymentintheaviationsectorisabitlater,2040’sto2060’s.Intermsofscale,afleetof200-300buseswouldneed5-7tonnesofhydrogenperday.Trucks,ontheotherhandwillneedapproximately100kghydrogenpertruck.Currently,smallpassengerferriesneed3tonneseverytwoweeks.Largerferries,however,willneed10-16tpd.Aninternationalairportmayneedthehydrogenequivalentof20millionlitersperdayofkerosene(~6000tpdhydrogen)tofunctionfully.Anditisestimatedthat650tonneswillbeneededforgridbackup.4.Costandtechnicalbarrierstouseofliquidhydrogeninemergingapplications.CostbarrierstotheadoptionofliquidhydrogeninemergingapplicationsincludetheuncertaintiesassociatedwithrequiredCAPEXandinsuringassetsfortheliquidhydrogeninfrastructure.Thelackofresearchfacilitiesthatcanhandleliquidhydrogenisacriticaltechnicalbarrier.Insufficientequipmentandliquefactionsupplierswerealsoidentifiedastechnicalbarriers.Onthepersonnelside,thereisapressingneedfortrainingandmaintenancepersonnelcompetentinthehandlingofliquidhydrogen.Finally,managingtheexpectationsofthecustomerwhencomparingliquidhydrogenandgasolineisanotherhurdlewhichmustbesurmounted.5.Safetycodesandstandardsconcernsforemergingapplications.Traditionally,safetycodesandstandardshavefocusedoncompressedgaseoushydrogenandnotliquidhydrogen.Increasedunderstandingandriskmanagementofleaks,firemitigation,andoverallresponsestrategiesastheyrelatetoliquidhydrogenareneeded.Materialscompatibilitywithhydrogenisalsoamajorconcernwiththeadoptionofliquidhydrogeninnewapplications.3.4LiquidHydrogenHandlingWiththeguidanceofthemoderator,attendeesineachoftheLiquidHydrogenHandlingbreakoutsessionswereaskedtoconsiderfourmaindiscussiontopics.1.Limitationsofrefuelingandhandlinginfrastructureandassociatedneeds.Astandardizedfuelingnozzlehasnotbeendefined.ISOislookingatthisissueforliquidhydrogentrucks,inpartnershipwithDaimler.ThisbodyofworkiscirculatingamongthevariousISOcommittees.Itwilltakesometimetodefineaninternationalstandard.Also,tankswappingisanoptionbeingexploredsinceitmakesthenozzlequestionamootpoint.Thereisn’tmuchinthewayofpumptransferbutusingpumpsmayavoidchangingpressureandtemperature.Timeismoneyandcustomersoftenhaveonlyalimitedwindowto31LIQUIDHYDROGENTECHNOLOGIESWORKSHOP–SUMMARYREPORToffload,soreplacingthewholetankmaybequicker.Thisapproachonlymakessenseifthequantitiesinvolvedwarrantit.Pumpsarenotrobustenoughinperformancetowarranttheexpenseandlosses.Pumpsaren’tneededforoff-loadingrightnow,ascurrentdeliverystructureissufficient.Pumpsontrucksarenotverycommon.It’smostcommontohaveliquidhydrogenpumpsontheground.Ifyouhavealargebunkeringvesselwithasuctiondevice,andyouhadmultipletrailerstooffload,thatmightbeascenarioworthexploring.Thisisentirelydependentontheapplicationthough.Itiscosteffectivetomoveliquidhydrogensinceitissolight.Itwouldbenicetohaveaforumonliquidhydrogenboil-off.Thereisn’tmuchofaconsensusonthistopic,althoughlotsofresearchiscurrentlybeingdone.SolutionsforLNGareoutthere(suchassub-cooling),sowhataboutliquidhydrogen?Boil-offishighlydependentontheapplication.Thetimethattheliquidhydrogenneedstobestoredinthetankisacriticalconsideration.Theuse-casemakesadifference,aswellasaddingtothecostandcomplexity.TheCanadianmilitaryislookingatprocuringelectricvehicles,eitherbatteryelectricvehicles(BEVs)orfuelcellelectricvehicles(FCEVs).Currently,itisnotclearwhichsingleoptionwouldmaximizetheirinvestment.Theyareinterestedtoknowwhetherliquidandgaseoushydrogenarecompetingconceptsorifbothwillbeusedand,ifso,where.DOEhostedaworkshoponbulkstoragewhereitwasstatedthatalloptionsarebeingconsidered.Onboardliquidhydrogenstorageisbeinginvestigatedformedium-andheavy-dutyvehicleapplications.Customersthatareusingandproducinghydrogenarelookingatwhenliquidhydrogenmakesmoresenseandwheregeologicstorageofgaseoushydrogenisnotaviableoption.Liquidhydrogenismoreattractiveespeciallywhenconsideringbulkstorage.Personalvehiclesmaybethemostcomplicatedapplicationareabecauseliquidhydrogenstorageisnotviableonboard.Itismorelikelythathigh-pressuregaswillbeusedinthoseapplications.However,fleetvehiclesandtrainscouldseeonboardliquidhydrogenstorage.Vehicleswithlongdutycyclesandregularusehavelessboil-offconcerns.Fromasafetyperspective,liquidhydrogenstoragecanbearguedtobeintrinsicallysaferthanhighpressuregaseousstorage,asitismorepredictablethangasoline,andwillnotleadtolongburnsbutwilldissipatequickly.2.NovelapproachestoliquidhydrogenhandlingMaritimeapplicationsofferuniquechallenges.Hugequantitiesofliquidhydrogenneedtobetransferredinashorttime.3.TrainingrequirementsforliquidhydrogenhandlingAtrainingstandardfortruckdriverstransportingLNGisindevelopmentinEurope.Thesamestandardsareneededforliquidhydrogen.Trainingforliquidhydrogenhasbeenlimited,duetonichemarketapplicationsforliquidhydrogen.Apprenticeshipscanprovideanavenue.Academiahasnottypicallyprovidedgoodtraining.Trainingrequirementscomefromindustry,butstillrequireOperationQualifications.Itwouldbebeneficialtohavemoreuniversaltrainingrequirements.ASP/AIChEmayofferatrainingcourseandcouldprovideuniversalrequirements.Considerationsforworkforcetrainingmustincludethoseoutsideofacademiaaswell.4.SafetycodesandstandardsforliquidhydrogenhandlingItmayhelptoconsiderwhothe“authorityhavingjurisdiction”isforaprojectandfocusonthecodesandstandardsthatapplythere.Muchoftheworktakingplaceistoensuretherequirementsareconsistentbetweenthedocuments,whichrequiresconsensus.ISOhasfocusedoncompressedhydrogeninthepastyear.Thereisinterestincreatinginternationalstandardsspecificallyforliquidhydrogen.DOEhasdonesomeworkwithgaseoushydrogentogaugetheimpactof32LIQUIDHYDROGENTECHNOLOGIESWORKSHOP–SUMMARYREPORTvariousleakscenarios.NFPAendedupreducingtheirsetbacksasaresult.Effortsareunderwaytodevelopasimilarstandardforliquidhydrogen.Fortruckrefueling,thehardwarecurrentlyavailablecannotadequatelysupportcurrentneeds.Uniquenozzledesignsareemployedbasedontheapplication.Thiswilltakeyearstosortout.PPEisnotahugeconcernforgaseousfueling.AnuntrainedmemberofthepublicwouldnotneedtobeconcernedaboutPPE.ThereisaneedforaconsistentmessageacrosstheindustrymakingitclearwhenPPEisneeded,suchaswithhandlingliquidhydrogen,though.Whatarethestandardsintermsofservicinghydrogenvehicles?Mostgaragesarenotequippedandoftentimesyouneedhighlytrainedtechnicianstosafelymaintainahydrogenvehicle.ThiswasagapidentifiedwhenLNGvehiclesthatweretakentotraditionalautomotivemaintenanceshops.3.5LiquidHydrogenStorageWiththeguidanceofthemoderator,attendeesineachoftheLiquidHydrogenStoragebreakoutsessionswereaskedtoconsiderfivemaindiscussiontopics.1.Limitationsofcurrentliquidhydrogenstoragetechnologies(keydriversofcost,barrierstoflexibility,efficiency,performance,reliability).Severallimitationsofcurrentstoragetechnologieswerehighlightedduringthebreakoutsession,firstofwhichwassupplychainconstraints.Thelackofahighvolume,reliablesupplyofcryogeniccomponentsandequipment,coupledwithlimitedmanufacturingcapability,isachallenge.Additionally,currentcomponenttechnologiessuchassealsandactuatorsfallshortintermsofperformanceandscale.Safetyconsiderationsforabovegroundstorage,suchasfootprint,setbackdistances,anddownstreamentrainmentmitigation,alsopresentadditionallimitations.Moreworkisneededinventstackdesignsforenclosedareas.Furthermore,thecurrentweightofliquidhydrogenstoragevesselsisabarrier,especiallyintransportationandaviationapplications.2.Limitationsofcurrentboil-offmitigationapproachesandbarrierstoimplementationofnewapproaches.Onelimitationtocurrentboil-offmitigationapproachesisthelackofintegrationbetweenboil-offandenduses.Participantsbelievedthatanoptimizedmitigationstrategywouldinvolveusingtheboil-offtofeedancillaryhydrogendemands.3.NovelapproachestoliquidhydrogenstorageandassociatedtechnologyreadinessThecryogenicfluxcapacitor,asemi-solidliquidhydrogenstoragesystemdevelopedbyNASA,washailedasanovelapproachtoliquidhydrogenstoragethatisreadytobecommercialized.Otherapproachesdiscussedincludedhighdensitygasstorageandcompressedcryogenichydrogenstorage.Cryogeniccompositetankswhichwouldbeusedmainlyforspaceandaircraftapplicationsweresuggestedasnoveltankoptions.Similarly,vapor-cooledshieldingtanks,whichcantakeboil-offvaporsandcirculatethemaroundthinpolymerfilms,werealsomentioned.Thepolymerfilmsinthesetanksarelightweightandtheirsizesandgeometriescanbecustomized.Thetechnologyisreportedtoenable20-literliquidhydrogenfillsin5-10minutes.Anothernovelapproachdiscussedwastheuseofportableliquidhydrogentankcartridgesinlieuoflarge-scaleliquidhydrogentransfers.4.Materialsneeds,designattributes,requirements&gapsAnurgentneedwithintheliquidhydrogenstoragefieldisformaterialswhichdonotexperiencehydrogenembrittlement.Moretestdataisneededtounderstandhydrogeneffectsonalternativematerialssuchas33LIQUIDHYDROGENTECHNOLOGIESWORKSHOP–SUMMARYREPORTceramicmatrixcomposites,carbonfibercompositesandhighentropyalloys.Developingtechniquestoreducethecostofthesenovelmaterialsisalsoimportant.Nitronicmaterials,forexample,havebeendeveloped,butthedemandtodrivedowncostdoesnotexistastheincumbent304/316stainlesssteelalloysareviewedas“goodenough”.Similarly,carbonfibercompositetransferlinescouldpotentiallyminimizeboil-offduetothelowercapacityofthecarbonfibers.However,costsandscaleupmechanismsareunknown.Highentropyalloyspossesshighductilityatverylowtemperaturesandhavethepotentialtoreplace304/316aslowercostalternativesbutneedtobefurtherevaluated.Thechoiceofmaterialanddesignattributeswoulddependgreatlyontemperatureandpressurewhileinuseastheseconditionsinfluencehydrogenuptake.Thermalstressesatcryogenictemperaturespresentthebiggestchallenge,butpressurebuildupisalsoveryimportant.Theuseofadditivemanufacturingforthedesignofinsulationandcoolingcomponentswouldbenefitthisworkaswell.5.Safetycodesandstandards-whatarethegapsandobstacles?Theexistenceofmultiple,andsometimeconflicting,sourcesofrequirements,codes,andstandardswasidentifiedasamajorobstacleintheimplementationofliquidhydrogenstorageprojects.Newplayersinthefieldareuncertainastowhatisneededtoensurecompliance.Also,thecurrentcodesandstandardsdonotsufficientlyaddressthecurrentstate-of-the-artforliquidhydrogenstorageintermsofquantity/scaleandthenecessarysafeguards.Aneedalsoexistsforaharmonizationofsafetyfactorsbetweentransportationandaviation(e.g.,throughtheH2-Aeroeffort).3.6BreakoutSessionReport-outFollowingthebreakoutsessionsoneachday,theattendeeswerereconvenedinthemainsessionandmoderatorsgaveabriefsummaryofthekeydiscussiontopicsfromtheirgroups.Asummaryofthereport-outslidesisshowninTable3.Table3.Summaryofreportslidesproducedbybreakoutsessionmoderators.LimitationsofconventionalHydrogenLiquefactionpathwaysLiquefactionneeds•R&Dtolowercostsinallaspectsoftheliquefactioncycle•FundamentalapproachneededNovelapproaches•Smaller,lessefficientscaleisstillvitalSafetycodesandstandards•Scaleandenduseareimportanttodeterminethebestsystem(casebyLimitationsofcurrentcase)pathways•UseofmixedrefrigerantormagneticrefrigerationNovelapproaches•Thecodesneedtocatch-upespeciallyforsub-cooledhydrogenSafetycodesandstandardsLiquidHydrogenDeliveryandDistributionconcerns•Speedandvolumeoftransfer:speedofgravityfeedinsufficient•Betterpumpsneededforlarge-scale,end-useapplications•Verylarge-scaleon-boardstorage(mining,off-road)needed•Swappingtanks/trailersinsteadofrefillingtanksforlarge-scaleenduse,suchasrail•Needimproveddesignofliquidhydrogentanks•Standardizationofloadingbays&connections•PPErelatedtorefuelinginfrastructure&interchangeabilityEmergingApplicationsofLiquidHydrogen34LIQUIDHYDROGENTECHNOLOGIESWORKSHOP–SUMMARYREPORTEmergingapplicationsof•Rangeextendersfortraditionalandshort-rangeaviation,Unitedliquidhydrogen,regions,andKingdom,2030-2035fortraditionalengines,2040forfuelcellstimelines•Trucks,busfleets,transportationclusters–fastfilltime(6-15Barrierstoadoptionminutes),2022,5-7tpdperbusdepotof200-300busesSafetycodesandstandards•Gridbalancingorresiliencyintheeventofgridoutagerequiresconcernshundredsofthousandsofgallons•Pickuptrucksandfarmequipment,UnitedStates•Passengerferriesandlong-rangeships,Norway,2024-2025,1tonneperweekforsmallferries,10-16tpdforlargerferries•Lackofresearchfacilitiesthatcanhandlecryogenichydrogen•Materialscompatibilitywithhydrogen•Uncertaintyofmarketmitigatescapitalinvestments•Nozzlefreeze-lock–influencestimeandreliability•Supplychainbuildoutforinsulation–couldbenefitfromstandardization•Availablesupplyofliquefaction•Availablestaff,skillsetsforoperationandmaintenanceofliquidhydrogen•Firemitigation/response–understandingofrelativeriskofliquidreleasesvs.gaseousreleases,understandingofavailablemitigationoptions(e.g.,improvedventilation,mitigationofignitionsource)•UnderstandingandmanagementofriskofleaksLiquidHydrogenHandlingLimitationsofcurrent•Useofheliumasthepurginggastechnologies•Transferterminationhasnotbeenupdatedsincethe1950’s•Alotofcodesandstandardsissues,makesitdifficulttodemonstrateliquidhydrogenstorage•AvailabilityofdispensingcomponentsforliquidhydrogenthatareeasytousewithoutPPERefuelingandhandlingneeds•Standardizednozzle/receptaclesforliquidhydrogenbeyondthetraditionalbayonet/pressuredriventransfers•Pumpsatparticularflowthresholds•Needforliquidhydrogenundergroundstorage,buriedtanksorvaults•Universalsetoftrainingrequirementusefulforvehiclemaintenancepersonnel,modeledaftergaseoushydrogenandLNG•Operationalqualificationsforhydrogen,carryoverfromnaturalgasNovelapproaches•InnovativematerialsforstorageincludingAl,Ti,polymersSafetycodesandstandards•Standardizedsetofrulestofollowneededtoallowrapidpermittingconcerns•Rationalizeliquidhydrogensetbackdistances•End-usecodesandstandardse.g.,foraircraftfuelingLiquidHydrogenStorageLimitationsofcurrent•Ventingboil-offinenclosedspacestechnologies•Mitigationofentrainmentdownstreamofventstacks•Industry’scurrentmanufacturingcapabilityforonboardtankse.g.,HDvehiclesandaviation•Weightofliquidhydrogenstorageforaviationandassociatedsupplychain•Lackofcommercialsizeperformancedataonintegratedrefrigerationandstoragesystemstechnologies,misalignmentinobtainingthenecessarydata,andwhatisneededfromtheengineeringperspective35LIQUIDHYDROGENTECHNOLOGIESWORKSHOP–SUMMARYREPORTMaterialsanddesignneeds•Newmaterials:fiberreinforcedpolymercomposites,ceramicmatrixNovelapproachescomposites,highentropyalloystoreplace304/316(higherductilityatcryogenictemperatures)Safetycodesandstandardsconcerns•Costandscalabilityofpolymertanks•Characterizationdatamadeavailabletogeneralpopulation•Government-fundedresearchanddemosofnewmaterials•Integrationofboil-offwithenduses;ideallyboil-offwouldbeoptimizedtofeedancillarydemandsforhydrogen•Useofboil-offtocoolspecifichighheatloadareasofthetankstructurehasbeensuccessfulinthepast•Vaporcooledshieldingtanks;usepolymerfilmstomakevaporshieldedvessels•Useofadditivemanufacturingforinsulationandcooling•Portableliquidhydrogentankcartridgesinsteadoflarge-scaletransfers,e.g.,forferries•Highdensitygasstorage–denserthanliquid•Nanoparticles,nanomaterialstorageresearch•Cryogenicandambientoptions•NASA’s‘hydrogenfluxcapacitor’•Carbonfiberinnervesselforcryo-compressedgasstorage•Harmonizationofsafetyfactorsbetweentransportationandaviation•Requirementsscatteredacrossmultiplesources,sometimesconflictingdirection/requirements•Setbackdistancerequirementsparticularlyforabovegroundstorage•Safetycodesandstandardsarelaggingcurrentstate-of-the-artonquantity/bulkstoragesizes/safeguards•Sub-cooledliquidhydrogenstorage/sub-atmosphericsafeguards/safetysystems•HigherpressureliquidhydrogenvesselsmaynotbecoveredbyASMEcode36LIQUIDHYDROGENTECHNOLOGIESWORKSHOP–SUMMARYREPORT4ConclusionsandRecommendationsClosingremarksweregivenbyNedStetson,HFTO.Hethankedpresenters,attendees,organizers,moderators,andscribesfortheirvaluablecontributions.Attendeesgavepositivefeedbackontheworkshopandwereappreciativeoftheopportunitytoparticipateintheinformativeandengagingevent.Participantswerealsoinvitedtoengageinotherupcomingworkshops.Theworkshopachieveditsobjectivetoaddressdevelopmentneedsforlow-cost,energy-efficient,scalable,andsafeliquidhydrogengeneration,dispensing,andenduse.Discussionsfocusedonstate-of-the-arttechnologies,research,development,anddemonstration(RD&D)gaps,innovativeconcepts,safety,andanalysisactivities.Therewasahighlevelofengagementfromexternalstakeholders,confirmingtheirinterestinliquidhydrogenasanimportantpartofthefutureenergyeconomy.TheworkshopwasavaluableopportunityforDOEtoincludetheminhelpingtoshapefuturepathwaystoachievecommongoals.Thebreakoutsessionswereinvaluable,andthepresentationsonrelevanttopicareassetthestageforproductiveexchange,asmanyquestionsanddiscussionsarosefromthecontentofthesepresentations.Topicsthatelicitedthemostdiscourseweretheneedforgreaterliquefactioncapacitytomeettheneedsforheavy-dutytransportationapplications,managingfastandefficientrefueling,thedesignofsuitableandinnovativestoragevesselsforlarge-scaleapplications,andliquidhydrogentransferprotocols.Theneedforregularreviewof,andupdatestoregulations,safetycodes,andstandardsrelatedtoliquidhydrogendelivery,handling,andstorage,wasarecurrentthemethroughouttheworkshop.Together,thepresentationsandbreakoutdiscussionswillallowDOEtobetterunderstandthevariouschallengesandopportunitiesforliquidhydrogeninmeetingfutureenergystorageandrefuelingdemand.KeyrecommendationsforDOEinclude:1)increaseresearchanddevelopmenteffortstoenhancetheefficiencyandcostofhydrogenliquefaction;2)furtherfocusresearchanddevelopmentofimprovedstoragetankdesignsandmaterialsforabovegroundandsubsurfacestorageofliquidhydrogen;3)reviewandsupportupdatestoregulations,safetycodes,andstandardsrelatedtoliquidhydrogendelivery,handlingandstorage;4)makefederalfundingavailabletoboostcomponentdevelopmentfortheliquidhydrogenecosystem;and5)continuedcollaborationbetweenDOEandNASA,aswellasotherfederalandstateentities.TheseactivitieswillprovidethestrongfoundationalsupportsystemonafederallevelthatwillallowliquidhydrogentobecomeamajorplayerinthefutureenergymarketandfulfillDOE’smissiontoensureAmerica’senergyandenvironmentalsecurity.37LIQUIDHYDROGENTECHNOLOGIESWORKSHOP–SUMMARYREPORTReferences1.https://www.energy.gov/sites/default/files/2021-10/lh2-storage-handling-demonstrations.pdf2.https://www.nasa.gov/content/space-applications-of-hydrogen-and-fuel-cells3.https://www.energy.gov/eere/fuelcells/liquid-hydrogen-delivery4.https://www.energy.gov/eere/fuelcells/advances-liquid-hydrogen-storage-workshop38LIQUIDHYDROGENTECHNOLOGIESWORKSHOP–SUMMARYREPORTAppendixThisappendixprovidesasummaryoftheworkshopagenda.DayOne-Liquefaction:CurrentStatusandRD&DNeeds11:00amOpeningremarks•DOEHydrogenProgramPerspectives(NedStetson,U.S.DepartmentofEnergy)•NASAPerspectives(MichaelMeyer,NationalAeronauticsandSpaceAdministration)11:20amCurrentState-of-the-ArtofHydrogenLiquefaction(OrianeFarges,AirLiquide)11:40amExperiencesandLessonsLearnedwithLiquidHydrogen(RajaAmirthalingam,PlugPower)12:00pmInnovativeApproachestoImproveScalabilityandEfficiency•AmgadElgowainy(ArgonneNationalLaboratory)•JacobLeachman(WashingtonStateUniversity)12:40pmBreak1:00pmLiquidHydrogeninEmergingLarge-ScaleMarkets(Jo-TsuLiao,Shell)1:20pmPanelDiscussionandQ&AwithSpeakers1:40pmBreakoutSessions•HydrogenLiquefaction•LiquidHydrogenDeliveryandDistribution•EmergingApplicationsofLiquidHydrogen2:20pmBreak2:35pmBreakoutSessionReportOut2:55pmDayOneClosingRemarksDayTwo-LiquidHydrogenStorageandHandlingInfrastructure:CurrentStatusandRD&DNeeds11:00amIntroductiontoDayTwo11:05amCurrentStatusofTechnologiesUsedforBulkStorageofLiquidHydrogen•AndyJacobson(CB&IStorageSolutions)•IanNeeser(ChartIndustries)11:45amPotentialBenefitsandChallengestoLiquidHydrogenforMD/HDvehicles•RajeshAhluwalia(ArgonneNationalLaboratory)•GladysAnyenya(WabtecCorporation)12:25pmCurrentPracticestoTransferandDeliverLiquidHydrogen•RaviSubramanian(GardnerCryogenicDepartmentofAirProducts)•AngelaKrenn(NASA-KennedySpaceCenter)1:05pmBreak39LIQUIDHYDROGENTECHNOLOGIESWORKSHOP–SUMMARYREPORT1:25pmSafetyRequirementsforLiquidHydrogenHandlingandRefueling(AaronHarris,HydrogenSafetyPanel)1:45pmMaterialsPerformanceatCryogenicTemperatures(JoeRonevich,SandiaNationalLaboratories)2:05pmBreakoutSessions•LiquidHydrogenHandling•LiquidHydrogenStorage2:45pmBreak3:05pmBreakoutSessionReportOut3:25pmWorkshopConcludingRemarks40Formoreinformation,visit:https://www.energy.gov/eere/fuelcells/liquid-hydrogen-technologies-workshopDOE/EE-2608▪June2022