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ShippingEmissions * Ultrafine * ParticleNumber * YourResearch


Shipping is a significant source of ultrafine particles in coastal areas.


Despite stricter regulations and lower fuel sulphur content, ships still emit considerable amounts of ultrafine particles.
This was proven by scientists from Tampere University, FMI and VTT measuring at sea and in engine laboratories.


“Shipping is the main source of anthropogenic particle emissions in large areas of the globe, influencing climate, air quality, and human health in open seas and coast lines. Here, we determined, by laboratory and on-board measurements of ship engine exhaust, fuel-specific particle number (PN) emissions for different fuels and desulfurization applied in shipping”

The research team measured emissions from a marine engine operating on low-sulphur fuels, natural gas, marine gas oil and marine diesel oil. They defined the particle number emission factor, size distribution down to 1 nm (1.2–414 nm) and volatility, electric charge, morphology, and elemental composition of the particles. The fresh exhaust particle size distributions were always bimodal, for all the fuels, with the nucleation mode concentrations much higher than the soot mode. Total particle number emission factors were of the order of 3 – 7  x 10^15  #/kWh. Emissions of the test engine were lowest for natural gas and highest for marine diesel oil. The researchers showed that combustion of liquid fuel generated 4–12 times higher soot mode particle emissions than combustion of natural gas, and that lower engine load (40%) that is typical for harbour areas caused higher total particle number emissions than a higher load (85%).

The researchers further compared emission factors to ship exhaust plume observations and estimated global aerosol particle number emissions from shipping.
The research indicated that most particles in the fresh ship engine exhaust are in ultrafine particle size range.
Shipping emissions are localized and observed close to coastal lines, but emissions are significant also on open seas and oceans.
“The global annual PN produced by marine shipping was 1.2 × 1028 (±0.34 × 1028) particles in 2016, thus being of the same magnitude with total anthropogenic PN emissions in continental areas. The reduction potential of PN from shipping strongly depends on the adopted technology mix, and except wide adoption of natural gas or scrubbers, no significant decrease in global PN is expected if heavy fuel oil is mainly replaced by low sulfur residual fuels.”

The research indicates that marine engines remain a significant source of anthropogenic aerosol particle number missions, mostly due to the nanosized particle emissions. Ship emissions should be considered in climate and health impact assessments.


Please read the full articles reporting the research:

Physical Characteristics of Particle Emissions from a Medium Speed Ship Engine Fueled with Natural Gas and Low-Sulfur Liquid Fuels
Alanen, J., Isotalo, M., Kuittinen, N., Simonen, P., Martikainen, S., Kuuluvainen, H., Honkanen, M., Lehtoranta, K., Nyyssönen, S., Vesala, H., Timonen, H., Aurela, M., Keskinen, J., Rönkkö, T.
Environ. Sci. Technol. 2020, 54, 9, 5376–5384

Shipping Remains a Globally Significant Source of Anthropogenic PN Emissions Even after 2020 Sulfur Regulation
Kuittinen, N., Jalkanen, J.-P., Alanen, J., Ntziachristos, L., Hannuniemi, H., Johansson, L., Karjalainen, P., Saukko, E., Isotalo, M., Aakko-Saksa, P., Lehtoranta, K., Keskinen, J., Simonen, P., Saarikoski, S., Asmi, E., Laurila, T., Hillamo, R., Mylläri, F., Lihavainen, H., Timonen, H., Rönkkö, T.
Environ. Sci. Technol. 2021, 55, 1 , 129-138.


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