US President Trump’s plans last week for delaying the 0.5% sulphur cap were defeated in the IMO who have introduced a supplementary measure about banning carriage of non compliant fuels unless the ship is fitted with scrubbers, to come into effect on 1 March 2020.
One method of ensuring compliance with the sulphur cap which comes into effect on 1 January 2020 would be the fitting of scrubber systems which though costly initially may prove more economical than the use of low sulphur diesel. Maersk has recently outlined its plans to go down the scrubber route, backtracking from its earlier position not to fit them to its fleet.
An article in todays ‘Guardian’ claims that the use of open-loop scrubbers which discharge wash water into the sea will simply transfer pollution from air to sea. Such discharges would have to comply with IMO regulations but there may still be a risk of some pollution involved. A 2015 study by UBA, a German environment agency, concluded that “wet scrubbers influence the marine environment through ph decrease, temperature increase, pollutant discharges and possibly through the use of active substances. Open scrubbers in particular have a greater environmental impact than closed or dry scrubbers due to their high water consumption and significantly larger amounts of generated washwater…The discharges of large amounts of washwater with partially persistent substances, lower ph and elevated temperature, however, are not compatible with the precautionary principles of [the EU’s] waste framework directive and Marine Strategy Framework Directive.”
The use of open-loop scrubbers is effectively banned in German and Belgian waters. However, the use of low sulphur diesel fuel in ports will contribute to other forms of air-borne pollution, such as from Nitrogen Dioxide emissions.
