Surveillance of Sulfur Emissions from Ships in Danish Waters
Report, 2017
The airborne dataset corresponds to approx. 900 individual ships, measured by sniffer or/and optical sensor over 245 flight hours. The optical sensor has low precision and is therefore used as a first alert system to identify ships running on high sulfur fuel. The precision of the airborne FSC meas- urements by the sniffer system is better and it is estimated as ± 0.05 % m/m (1σ) with a systematic bias of - 0.045 % m/m. Therefore only ships running with FSC of 0.2 % m/m or higher can be de- tected as non-compliant ships with good confidence limit (95 %) by the airborne sniffer system. The airborne measurements during 2015 and 2016 on Danish waters show that 94 % of the ships complied with the EU Sulphur directive, at the 95 % confidence limit. The compliance rate was lower, 92 %, during the 2nd half of 2016.
In the period June 2015 to May 2017, 8426 sniffer measurements of individual ships were carried out at the Great Belt Bridge. However, there were technical problems in the first part of the project and the sniffer therefore had reduced sensitivity the first year and only high sulfur ships (> 1 % FSC) could be detected as non-complying vessels with appropriate statistical confidence.
The precision in the estimated FSC by the fixed sniffer system is estimated as ± 0.04 % m/m (1σ) with a systematic bias of - 0.055 % m/m. Therefore only ships running with FSC of 0.18 % or higher can be detected as non-compliant ships with good confidence limit (95 %) by the fixed sniffer system. The data for the period June 2016 to October 2016 show a compliance rate of 94.6 % which increased to 97.4 % in the period January 2017 to May 2017.
The compliance level during different time periods and platforms varied between 92-97 %. Here 1 - 2 % of the ships were in gross non-compliance with the EU sulfur directive with FSC values above 0.5 % m/m. There were differences over time, with the highest values in the summer of 2016. The compliance level was close to the values (95 %) measured by port state control authorities in Sweden and Denmark 2015 and 2016. When comparing ships measured by port state and the ones in this project it can be deduced that the efficiency of finding non-compliant vessels could be increased by at least a factor of 4, if the port state controls were guided by measurements. Most of the non-compliant ships (90 %) were measured high only once. But there were cases with individual ships and ship operators that were more abundant in the non-compliance statistics. The non- compliant ships that were seldom in the area around Denmark had higher emissions of SO2 than the non-compliant ones that operated their more frequently. On several occasions during this study we encountered ships equipped with scrubbers that were non-compliant with respect to the EU sulfur directive.
Author
Johan Mellqvist
Microwave and Optical Remote Sensing
Jörg Beecken
Microwave and Optical Remote Sensing
Alexander Vladimir Conde Jacobo
Chalmers, Earth and Space Sciences, Optical Remote Sensing
Johan Ekholm
Chalmers, Earth and Space Sciences, Optical Remote Sensing
Driving Forces
Sustainable development
Areas of Advance
Transport
Subject Categories
Marine Engineering
Control Engineering
Signal Processing
DOI
10.17196/DEPA.001
Publisher
Chalmers