Comparison of emission factors of particles from shipping using different equipment

Air quality in urban cities with ports can significantly be impacted by shipping. For example Visschedijk and Denier van der Gon (2022) showed that, within Rotterdam area (the Netherlands), sea shipping is the main source of ultra-fine particles (UFP) with a contribution of 56% to total UFP emissions. Within EU-project SCIPPER (Shipping Contributions to Inland Pollution Push for the Enforcement of Regulations) a measurement campaign of six weeks was undertaken at the river Elbe near Hamburg (Germany). Sea going vessels pass by on the way to or from the port of Hamburg, which is located about 10 km upstream of the measurement site. Three different groups measured side-by side different gaseous compounds and aerosols on-shore. The aerosol measurements consisted of different equipment measuring different sizes ranging from 6 to 10 000 nm, also black carbon was measured by two groups. The emission factors (EF) of the different ships were calculated in #/kg fuel as well as mg/kg fuel from these measurements. This provides a unique dataset to better understand the emission characteristics of different ships as well as the comparability of different devices. This comparability is important if in the future legislation to decrease aerosol emissions of shipping is applied and needs to be verified. Results showed the relatively large contribution of mainly ultrafine particles, with 90% of the total amount of particles being smaller 80 nm and 75% of the total particle mass comes from particles smaller 200 nm. The comparison showed very promising results when the same equipment was tested side-by-side (R² above 0.85 for all size ranges). The comparability of EFs of same sources that were measured by different devices was somewhat lower, but especially for smaller size ranges still promising (R² of 0.69 for particle number ranging from 90 to 300 nm). For black carbon the experimental set-up proved to be too different (drying vs non-drying and different inlet cut-offs) to give comparable emission factors. Concluding the data showed promising results to be able to use on-shore monitoring in the future to monitor aerosol ship emissions, also when using different equipment.

References:

Visschedijk, A., Denier van der Gon, H. (2022). UFP emissie in de Rijnmond regio in 2019 (in Dutch). Utrecht: TNO-report R10616.