The Maritime and Port Authority of Singapore (MPA) said yesterday that it is banning, with effect from Jan 1, 2020, the discharge of "wash water" used in ships to scrub engine exhaust.
The ban on so-called open-loop scrubbers in Singapore, home to the world's top ship refuelling or bunkering hub, is a potential setback to shippers that have invested millions in the exhaust gas cleaning systems.
The move is to help prepare one of the world's busiest ports for new International Maritime Organisation (IMO) rules that come into force in 2020 and oblige ships to use cleaner fuels.
"To protect the marine environment and ensure that the port waters are clean, the discharge of wash water from open-loop exhaust gas scrubbers in Singapore port waters will be prohibited," said Mr Andrew Tan, MPA's chief executive officer, during an event in Singapore.
"Ships fitted with hybrid scrubbers will be required to switch to the closed-loop mode of operation," he added, saying Singapore will be providing facilities for the collection of residue generated from the operation of scrubbers.
The MPA told Reuters separately that the ban "is already part of our current legislation" but that its enforcement would start from Jan 1, 2020. The IMO, the United Nations shipping agency, shook the fuel and maritime industries in 2016, when it said it would ban ships from using fuels with sulphur content above 0.5 per cent from Jan 1, 2020, compared with 3.5 per cent now.
To comply with the new rules, shippers can switch to burning costlier but cleaner fuels like marine gasoil or low-sulphur fuel oil, shift to alternative fuels like liquefied natural gas, or invest in exhaust gas cleaning systems, known as scrubbers.
Open-loop scrubbers use seawater as a scrubbing liquid and the waste stream is treated before being discharged back into the sea. In closed-loop systems, scrubbing is done using water treated with additives and the liquid is recycled back into the scrubber.
A spate of scrubber installation orders this year has led energy researchers to raise their demand forecasts for high-sulphur fuel oil (HSFO) bunkers as the scrubbers will let ships continue to burn HSFO once the IMO's sulphur rules go into effect.