Ensuring compliance with the IMO 2020 regulation isn’t just about fuel selection; the actual switchover process from heavy fuel oil to new, low-sulphur alternatives needs careful management, writes Luca Volta, Marine Fuels Venture Manager, ExxonMobil.
The International Maritime Organization’s (IMO) 0.50% sulphur cap will dramatically change the fuels landscape. Unlike the introduction of Emission Control Areas (ECA), the IMO’s latest emission regulations set a global limit that will require vessels to make a permanent change in fuel selection, unless operators opt to fit abatement technology
Vessel operators are asking how to comply by 1 January 2020 with the changing emissions target, what types of fuels will be available and where. However, ensuring compliance isn’t just about fuel selection; the actual switchover process from heavy fuel oil (HFO) to new, low-sulphur alternatives needs careful management. There are also implications for lubricant selection.
A number of important steps must occur prior to bunkering a low-sulphur fuel, so vessel operators will need to work out arrangements that meet the specific requirements of their vessels. Without prudent plans in place, operators run the risk of non-compliance and costly fines. They must also plan for fuel availability, given the possibility that some ports will initially be unable to meet industry demand. A high-sulphur fuel carriage ban is likely to come into force by 1 March 2020.
Unless a vessel is fitted with abatement technology, commonly known as a scrubber, operators will need to ensure that their fuel tanks do not contain high-sulphur HFO by the IMO deadline. Fuel tanks will probably retain sediment from the existing HFO, which is likely to contain those higher levels of sulphur. If this is not removed, there is the risk that the sulphur will contaminate compliant fuel, pushing its sulphur content above the 0.50% limit.
ExxonMobil expects that many compliant fuels entering the market will have a sulphur content very close to the 0.50% cap, so even very low levels of residual sulphur left in a fuel tank could tip a vessel over the IMO’s limit.
To minimise this risk, ExxonMobil recommends that vessel operators flush fuel tanks with a distillate-based product to help remove sludge deposits. This process may need to be repeated, depending on the amount of residue present. In some instances, tank bottoms may have to be manually cleaned.
The fuel used to flush tanks could contain damaging levels of cat fines, which will require on-board treatment. Vessel operators must factor in how long these processes could take and keep in mind that any sludge removed from the tanks will need to be disposed of properly.
Operators should remember that the storage, handling and treatment of 0.50% fuels will involve bunkering fuels of a wider variety of viscosities, types and formulations than seen today. On-board handling practices have to take into account likely changes in fuel types, including fuel segregation and routine compatibility testing.
Cylinder oil stock depletion
One benefit of the 0.50% cap is that vessels will be able to streamline their lubricant inventory as only one cylinder oil will be required. Vessels with scrubbers will continue to use HFO and high BN oils, while those who choose to switch to low-sulphur fuels will need correspondingly low BN formulations. These vessels must deplete their stocks of high BN cylinder oils prior to the IMO deadline to avoid waste and disposal costs.To ensure compliance, ExxonMobil recommends that vessel operators work with suppliers who have adopted the latest ISO 8217:2017 fuel standard and have the proven technical expertise to help them navigate the upcoming changes.