IMO regulations to reduce sulphur oxides (SOx) emissions from ships first came into force in 2005, under Annex VI of the International Convention for the Prevention of Pollution from Ships (known as the MARPOL Convention). Since then, the limits on sulphur oxides have been progressively tightened.
What must ships do to meet the new IMO regulations?
Ships can limit the air pollutants by installing exhaust gas cleaning systems, also known as “scrubbers”. This is accepted by flag States as an alternative means to meet the sulphur limit requirement. These scrubbers are designed to remove sulphur oxides(SOx) from the ship’s engine and boiler exhaust gases. So a ship fitted with a scrubber can use heavy fuel oil, since the sulphur oxides emissions will be reduced to a level equivalent to the required fuel oil sulphur limit.