Discussions have started up at IMO about the need and potential for restricting black carbon (BC) emissions in the Arctic region caused by international shipping.
Especially regarding switch of fuel quality – from residual fuel (HFO) to low sulphur distillate fuel (LFO) – as a measure for reducing black carbon emissions from ships, various contradictory opinions have been expressed. Some investigators are stating that switching to LFO (from HFO) would be an efficient measure to reduce black carbon emissions but many others are of the opinion that this measure would not have any significant effect.
In 2012 CIMAC Working Group 5 “Exhaust Emissions Control” (WG 5) published the document “Background information on Black Carbon Emissions from Marine and Stationary Diesel Engines – Definition, Measurement Methods, Emission Factors and Abatement Technologies”. The conclusion in this document is that “switching to low sulphur and distillate fuel will typically not result in reduced black carbon emissions”. This conclusion was based on real measurements and evaluation of existing literature data.
At the IMO BLG 16 meeting in January 2012 a presentation was made by Dan Lack from The National Oceanic and Atmospheric Administration & University of Colorado, concluding that “black carbon emissions drop by at least 50% when switching from low to high quality fuels” i.e. switching from HFO to LFO.
As the conclusion made by Dan Lack is different from that of CIMAC Working Group 5 publication, this CIMAC document was prepared by WG 5 providing comments to Dan Lack´s presentation.