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Marine environmental awareness course. Other emissions to air (SOx, NOx, PM). Name – Date. Other emissions to air (SOx, NOx, PM). Contents Introduction Main problem areas Acidification Air quality Role of shipping. 2. Photo credits: North Sea Foundation. 1. Problems and pollutants.
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Marine environmentalawarenesscourse Other emissions to air (SOx, NOx, PM) Name – Date
Other emissions to air (SOx, NOx, PM) Contents • Introduction • Main problem areas • Acidification • Air quality • Role of shipping 2 Photo credits: North Sea Foundation
1. Problems and pollutants This lecture focuses on effects of engine emissions Air quality (smog - health problems) Acidification Climate change Air quality (smog - health problems) AcidificationClimate change Photo credits: Job Orbiso
This lecture focuses on effects of NOx, SOx, PM and associated problems: Air quality Acidification Credits: Air Pollution and Climate Secretariat/NOAA’s National Weather Service Collection John Neander/ProSea
SOx emissions are directly related to the sulphur content of fuel Illustration credits: Air Pollution and Climate Secretariat
NOx emissions depend on conditions inside the engine • examples: NO, NO2, ... • Engine emissions:nitrogen (N2) in air reacts with oxygen (O2) in air • level of NOx emissions depend on conditions inside engine (eg temperature, air:fuel ratios) • ‘NOx paradox’ • Lower temperatures = lower NOx emissions (but less efficient combustion, so more CO2!)
Particulate Matter (PM) also formed in ship engines • Very small particles: PM10–PM2,5 • Mixture of sulphates, ash, unburnt fuel • 60-70% of PM emissions is directly related to bunker fuel quality (Wartsila) Illustration credits: California Environmental Protection Agency
2. Main impacts - acidification • NOx, SO2 in the air react with water and form acids • Results in lower pH (= higher acidity) in the environment • Often called acid rain (but also dry deposition) Illustration credits: Air Pollution and Climate Secretariat/Science – How Stuff works
Consequences of acidification • soil loses nutrients (e.g. calcium): • damage to trees / plants • soil releases heavy metals: • toxic to fish / insects (surface water) • toxic to humans (ground water) • surface waters: over-fertilization • buildings: damaged by corrosion • A prominent environmental issue in the 80’s (in Europe) • Currently less problematic • - Not completely solved Photo credits: ProSea
Main impacts – air quality • NOx, SOx, VOC and PM emissions contribute to formation of smog • main component is ozone (O3) • Ozone at ground-level: toxic to humans • Consequences: • irritates lungs and eyes • chest tightness • leaf damage (plants and trees) • lower crop yields Photo credits: NOAA’s National Weather Service Collection John Neander/ EPA
Main impacts – air quality (PM) • PM10 and smaller: • undetected by our lungs • remain in respiratory system • pass into blood stream • Health effects include: • premature deaths • heart and lung failures • asthma • (chronic) bronchitis • cancer (possibly) 725,000 years lost in the EU alone
3. Role of shipping Acidification and air quality are problems at regional scale. Shipping also contributes! because 70% of shipping activities are within 400 km distance from coast Photo credits: National Centre for Ecological Analysis and Synthesis, University of California, Santa Barbara
Contribution of SOx, NOx by shipping expected to grow Shipping emissions are expected exceed all EU land emissions by 2025 Business as usual scenario! SO2 NOx EU27 = land-based sources in all EU countries (incl. domestic shipping) Sea = international shipping in European sea areas …as land emissions decrease: relative contribution of shipping increases! Illustration credits:Air Pollution and Climate Secretariat
Worldwide, total sulphur emissions are increasing fastest close to main shipping lanes Journal of Geophysical Research Illustration credits: Journal of Geophysical Research
Contribution of SOx, NOx, and PM by shipping • In some ports (e.g. Long Beach California), shipping already is a major (36% for NOx) if not the biggest source (70 % of SOx) • Cruise ships sailing in Californian waters produce 10 tons of NOx and PM per day • A cruise ship in port for one day = 12,400 cars (PM and NOx)
SOx regulations for ships • Annex VI from MARPOL: • Global sulphur cap for HFO = 4,5% in fuel (45,000 ppm) • (Fuel now contains 2,7% suphur! on average) • Limit in Sulphur Emission Control Areas = 1,0% • In the future: • 2018 – feasibility study (oil companies)
NOx regulations for ships • Annex VI from MARPOL • Maximum 17 g/kW • Emission standards related to revolutions per minute (rpm) • Tighter nitrogen oxide emission standards for new engines • Only for new ships! • Tier III only in NECAs
No specific regulations Annex VI Lower sulphur content in fuel and emissions will cut PM emissions significantly PM regulations for ships
Reducing SOx, NOx and PM emissions (solutions) • Shore side power (Sweden and California) Photo credits: Port of Gothenburg
Reducing SOx and PM emissions (solutions) 1) Fuels with lower sulphur content • Distillate fuels (MDO): 90% less SOx, 70 % less PM • Alternative fuels (LNG, biofuels, ...) • 2) After treatment of emissions: sea water scrubbers • >95% SOx reduction • Downside: highly acidic waste produced by scrubber
Reducing NOx emissions (solutions) • 1) Engine based measures • Dry low NOx technologies (such as Miller timing) lower T (but, CO2 emissions increase) • Wet low NOx technologies (adding water) • Exhaust gas recirculation • 2) After treatment: Selective Catalytic Reactor (SCR) • Needed for Tier III! (90% reduction of NOx) • Uses urea or ammonium (NH3 N2 and H2O) • Risk: NH3 slip Photo credits: Job Orbiso