Effect of speed reduction on particle emissions of ships

Speed and power reduction, "slow steaming" (SS) is a means of saving fuel in shipping. Consequently also changes in emissions are probable. The special significance is in the fact, that impact of BC in the atmosphere has increased, and the Arctic is a delicate environment for increasing marine traffic. Particle emission changes are combinations of variations of engine power and fuel quality. The effect of fuel quality will be emphasized and changed as the global, EU, SECA and local regulations for fuel sulphur S are finalized between 2015-2015 to the new 0.1-0.5 w-% S caps. As regards fuel quality, during the recent fuel S regulations it has not been certified that soot emissions would be reduced as with reducing fuel S. The study concerns the effect of lowering ship speed and/or power of the engine especially on particulate number (PN) and solid carbonaceous matter, soot, emissions. Emission sources were 4-stroke marine engines, and the fuel S contents 0.9-1.0 %. For the vessel speed reduction - fuel oil consumption (SFOC) relationships both 4-stroke and 2-stroke engine operations were estimated.