exhaust gas cleaning – the obvious solution?
TRANSCRIPT
Exhaust Gas Cleaning – The Obvious Solution?
SUSTAINABLE SHIPPING CONFERENCE30th September 2009San Francisco, California
Donald Gregory, Director EGCSA
NOx e mis s ions re gula tionsMARPOL Annex VI ( 2010)
Nitroge n Ox ide Emis s ions ( re gulation 13)– Tier 1 applies to all engines installed from 1st January 2000– Tier 1 retroft will apply to engines installed from 1st January 1990 12 months from renewal survey
• Retroft applies only in cases where a retroft kit is available and installation meets certain economic criteria
– Tier 2 applies to all engines installed from 1st January 2011– Tier 3 applies to all engines installed from 1st January 2016 when operating in an ECA with Tier 3
NOx emissions in force• Pre 2016 vessels may operate in an ECA with Tier 3 NOx emissions in force (at Tier 1 or 2 subject to criteria
above)
SOx e mis s ions re gula tions MARPOL Annex VI ( 2010)
Sulphur Ox ide & Pa rtic ula te Matte r Emis s ions ( re gulation 14)
– Emissions limits based upon emission of equivalent sulphur content of fuel– From July 2010 global cap on sulphur content of fuel ceases– From July 2012 an emissions limit based upon emission of a 3.5% sulphur content fuel applies
globally– In 2018 a study will be conducted to ascertain the feasibility of reducing the global emission to an
equivalent of a 0.5% sulphur fuel
Ex ha us t Ga s Cle a ning Sys te ms (EGCS)
Ope rating Princ iple
Applic a tion SOx PM NOx
CO2
C.B.
Selective Catalytic Reduction (SCR)
Several installations, uses ammonia & catalyst but not effective at low loads
Non Thermal Plasma (NTP)
Still in development, uses fuel instead of ammonia for reduction
Sea Water Scrubbing Widely used and effective
Fresh Water Scrubbing Uses Caustic Soda for neutralisation and sequesters some CO2
Hybrid Scrubbing Either sea water or caustic scrubbing hence more easily manages discharge pH
Process Plant Scrubbing On barge system using conventional chemical processing of scrubbed gas
Low Sulphur Fuel Multiple fuels to suit areaNotes1.SOx >99% reduction possible – emission below 0.1%S fuel equivalent2.PM quite effective with scope for further significant reductions3.NOx scrubbing likely to be a niche application as engine designers meet Tier II and Tier III with in-engine controls4.Some limited sequestration of CO2 possible
Ex ha us t Ga s Cle a ning Sys te ms
mv Baru – Clean Marinemv Pride of Kent – Krystallon
mt Suula – Wartsila mv Tor Facaria – Aalborg Industries
Ex ha us t Ga s Cle a ning Sys te ms
mv Baru – Clean Marine
mt Suula – Wartsila
AMECS Systems - ACTi
mv Shanaz- MES
PM & Ca rbon Bla c k
PM (na no to mic ron s ize ra nge )
• Primary – direct combustion products
– Ash from fuel & lube oil– Unburnt & semi-burnt fuel
• Secondary – in-direct post combustion in-atmosphere reactions
– Ammonium sulphates (eliminated by scrubbing)– Particles form during air dilution and cooling
Ca rbon Bla c k (na no s ize ra nge )– Low rate of fall-out– Hypothesised contributor to global warming– Potential human health impact– Evidence of rate by fuel type unconfrmed (eg diesel or residual fuel)
Size ra nge of c onta mina nt pa rtic le s
• Diesel engine size ranges include– Nano particles <50 nm– Ultrafne particles < 100 nm (highest number)– Fine particles <2.5 µm– PM 10 <10 µm
1 10 100 1000 10 100 1000 10nm µm
Dust in buildings
Carbon Black
Talcum Powder
Oil Mist
Cement Dust
Diesel Exhaust
PM Cre a tion & Me a s ure me nt
Ref erence – Technology Today, Spring 2006Dr Imad A. Khalek, SwRIThe Particulars of Diesel Particle Emissions
Atmospheric dilution and cooling of diesel exhaust may trigger the nucleation of new particles such as semi-volatile hydrocarbons and sulphuric acid
The choice of filter media used for particle collection can have a large influence on measured particle emissions downstream of a diesel particle filter
PM Ma s s , Count & Inha la tion/De pos ition
Reference: Aerosols Handbook: Measurement, Dosimetry and Health EffectsEdited by Lev S Ruzer & Naomi H. Harley
Inhalation & deposition Maximum Particle Count
Maximum Mass
Sc rubbe r La b Te s t
• Test at MAN Holeby, Denmark• Test engine MAN rated at 1MW• Gas Phase Scrubbing Effciency
– SO2 reduction 90% - 98% (mass)
– PM reduction 50% - 85% (mass)– CO2 reduction 15% (mass)
• PM measurement by mass (table below)
FUEL PM BEFORE ( g /kWhr)
PM AFTER( g /kWhr)
DMA (6ppmS)
0.303 0.037
RMG 180 (0.5%S)
0.753 0.222
RMG 180 (1.7%S)
1.031 0.343
Bla c k Ca rbon
• Incomplete combustion of fossil fuel & biomass• Short lived in the atmosphere• Increases warming effect
– Absorbing heat in the atmosphere– Reducing albedo of snow and ice
• Potent climate forcing agent– IPCC estimate 0.3 W/m2– Recent estimates 1 – 1.2 W/m2– Possibly 55% of CO2 forcing
– Possible as potent as CO2 on ice caps
• Elimination of BC production– Effective in days or weeks– Estimated to slow climate change by 10 to 20 years– University of Illinois estimate 14% of BC from transport diesel
PM Me a s ure me nt on Ma rine Die s e l Engine s
• Erik Fridell et al ....Primary particles in ship emissions– Coarse mode was large when compared to distributions in small diesel engines– Number & size distribution & type of particle important for climate change– Sulphur emissions dominate PM emissions– PM emissions not consistent between engines
• A. Kasper et al....Particulate Emissions from a Low-speed Marine Diesel Engine
– High amount of small particles (20-40nm)– Did not exhibit accumulation mode– Most particles consisted of volatile particles– Further studies needed to understand the results
• PM measurement inconsistent• Methods of measurement
– What is the right method?– Which are the harmful particles?
Ex ha us t Ga s Cle a ning Ste p 2
• Stage 1 EGCS facilitate further cleaning• Electrostatic precipitators• Membranes/traps• Non thermal plasma• Oxidation catalysts• Other technologies already being used ashore
The c ha lle nge s & re w a rds
CHALLENGES• Defne the target PM• Develop stage 2 cleaning technologies• Ensure system operational simplifcation• Avoid high maintenance technologies• Ensure measurement protocols provide performance confdence
REWARDS• Meet signifcant portion of CO2 emissions targets by elimination of
BC• Simplify and increase options for future fuel selection• Further enhance energy effciency
Exhaust Gas Cleaning Systems can enable the highly effcient marine diesel engine to meet current and future air quality
requirements whilst not constraining future fuel options