Reanalysed Ship Emission Measurements

Air pollution from fossil fuel powered ocean-going vessels (OGVs) is responsible for various environmental and human health issues worldwide. Specifically for sulfur oxides (SOx), from 2010 onwards, stricter standards came into force regarding the maximum allowable fuel sulfur content (FSC) in marine fuels in the European Sulfur Emission Control Area (SECA). A method was developed for the airborne monitoring of OGVs to evaluate their compliance by equipping the Belgian coastguard aircraft with a sniffer sensor. The sensor allows a highly accurate FSC determination based on real-time CO2 and SO2 measurements in the smoke plume of OGVs. In addition to the worldwide tightening of standards for sulphur emission from Ocean Going Vessels (OGVs), action was also being taken to reduce nitrogen emission. On January 1th, 2021 the NOx Emission Control Area or NECA for the North Sea and Baltic Sea came into effect. The NOx emission limit values apply to every marine diesel engine with a capacity of more than 130 kW. The emission standards (NOx limit in g/kWh) depend on the optimal operating speed of the engine or 'Rated Engine Speed' and are based on the ship’s keel laying date which divide the OGVs fleet into four tiers. A method was developed for the airborne monitoring of OGVs to evaluate their compliance by extending and modifying the sniffer sensor system in the Belgian coastguard aircraft with a NOx sensor for real-time CO2 and NOx measurements in the exhaust plume of OGVs.