The average sulphur content of fuel oil used for marine diesel engines is 2.7%. This will undoubtedly change with the coming emission legislation, which will lower the emission limits of SOx, NOx, particulate, HC and CO.

So far, the authorities have reduced the SOx content in the exhaust gas by intro- ducing limits on the content of sulphur in the fuel oil used. This is a much more efficient and straightforward solution, obtained from the refining process, than the installation of separate complicated SOx cleaning facilities on board each vessel.