NewcastleSchool ofMarineUniversityScience&Technology。Mitigating technologies forcleanerairDrKayvanPazoukiwww.ncl.ac.uk/marine
Mitigating technologies for cleaner air Dr Kayvan Pazouki
NewcastleSchool ofMarineUniversityScience&TechnologyntroductionIn theyear2000,airpollutantsfrom international shipping intheEuropeanwatersamounted20~30%ofNOxandSO2emissionsfromallland-basedsourceinEU.AnnexVIofMARPOL73/78enteredintoforceon1gthMay2005Global shippinghas increased (intonnes)5.5%annuallyfrom2000to 2007.Increased inshipping activities has offset thepositive impact oftheemissionregulations.IMO agreed onstrictermeasuresonNOxand SOxfromships.Shipping also contributes to anthropogenicclimate changethroughemissionofcO2:Maritime shipping is estimated to emit around 3%of the globalGHG.2www.ncl.ac.uk/marine
Introduction • In the year 2000, air pollutants from international shipping in the European waters amounted 20~30% of NOx and SO2 emissions from all land-based source in EU. • Annex VI of MARPOL 73/78 entered into force on 19th May 2005. • Global shipping has increased (in tonnes) 5.5% annually from 2000 to 2007. • Increased in shipping activities has offset the positive impact of the emission regulations. • IMO agreed on stricter measures on NOx and SOx from ships. • Shipping also contributes to anthropogenic climate change through emission of CO2 . • Maritime shipping is estimated to emit around 3% of the global GHG
NewcastleSchool ofMarineUniversityScience&TechnologyPrincipal Emissions of Interest.Sulphurderivatives SOx("preferably"SO2:SO if poorcombustion)PrincipallyfromsulphurpresentinfuelIMOregulationslimitingfuelsulphurcontent(provisionforuseofscrubbers infuture)NitrogenderivativesNOX(mainlyNOandNO2)Productofcombustionprocess;promotedbyHightemperatures/longresidencedurations/oxygenabundancesIMOregulationsrelatingtoengineperformance(tierrating)anduseofCatalyticConverters(SCR)CarbonderivativesCOx("preferably"CO2:CO if poorcombustion)InevitableconsequenceofusingfossilfuelIMOguidelines(will leadtoregulation)onefficientdesignandoperationofshipsEEDl/EEOl-recognisingthatreducingtheamountofcarbon consumedperunittransporteffortwill reducetotalcarbonfoot-printParticulatematterPMCondensationofHCandSulphates,accumulationofunburnedcarbon(blackcarbon/soot)Promotedbypoorcombustion(insufficientAFR/coolregionsincombustionspace/poorenginecondition)NoIMOregulationsUnburned hydrocarbonsHCPromptedbypoorcombustion(insufficientAFR/cool regionsincombustionspace/poorenginecondition)NoIMO regulationsrwww.ncl.ac.uk/marine
Principal Emissions of Interest • Sulphur derivatives SOX (“preferably” SO2 : SO if poor combustion) – Principally from sulphur present in fuel – IMO regulations limiting fuel sulphur content (provision for use of scrubbers in future) • Nitrogen derivatives NOX (mainly NO and NO2 ) – Product of combustion process; promoted by High temperatures/long residence durations/oxygen abundances – IMO regulations relating to engine performance (tier rating) and use of Catalytic Converters (SCR) • Carbon derivatives COX (“preferably” CO2 : CO if poor combustion) – Inevitable consequence of using fossil fuel – IMO guidelines (will lead to regulation) on efficient design and operation of ships – EEDI/EEOI – recognising that reducing the amount of carbon consumed per unit transport effort will reduce total carbon foot-print • Particulate matter PM – Condensation of HC and Sulphates, accumulation of unburned carbon (black carbon/soot) – Promoted by poor combustion (insufficient AFR/cool regions in combustion space/poor engine condition) – No IMO regulations • Unburned hydrocarbons HC – Prompted by poor combustion (insufficient AFR/cool regions in combustion space/poor engine condition) – No IMO regulations
NewcastleSchool ofMarineUniversityScience&TechnologyExhaustEmissionsandCompositionsPollutants0.3%100(%) SUIO6%CO2H,O8.1%HEAT11.3%OPM0.257cO(u%/b)0.6HC13.0%028075.8%AIR8.5kg/kWh5.6%so,10Engine5.35%EXHFUEL175g/kWh50GASProcess1500.ppmNO74.3%N2288600ppmLUBE1g/kWh60ppm180ppm120mg/NmPMNO1025WORKTypicalexhaustemissionfromamodernTypicalcompositionofexhaustgasproductsofmediumlow-speeddieselenginespeeddieselengine,burningfuelwith3%sulphurcontenton averagewww.ncl.ac.uk/marine
Exhaust Emissions and Compositions Typical exhaust emission from a modern low-speed diesel engine Typical composition of exhaust gas products of medium speed diesel engine, burning fuel with 3% sulphur content on average
NewcastleSchool ofMarineUniversity+Science&TechnologyEmissionReductionTechnologiesPre-combustionmethodsMeasures and technologies modify either air orfuel prior admission to theengineinordertorestrictformationofNOxand/orSOxPre-combustionmeasuresCombustionHumid AirExhaust gasAlternativeWaterin fuelair saturationMotorsFuelsrecirculationsystemLS FuelLNGHydrogenwww.ncl.ac.uk/marine
Emission Reduction Technologies • Pre-combustion methods: Measures and technologies modify either air or fuel prior admission to the engine in order to restrict formation of NOx and/or SOx