(www.MaritimeCyprus.com) In order to comply with the new sulphur limit for fuel oil used on board ships taking effect from 1 January 2020, residual fuel oils with sulphur contents of 0.50% or lower (hereafter, referred to as "compliant fuel oils" in this booklet) will be distributed globally and loaded on board ships. Consequently, the number of occasions where fuels for main engines or auxiliary engines are changed from conventional fuel oils to compliant fuel oils and actually used will increase.
The Authors, having summarized the potential risks related to the changing over from conventional fuel oils to compliant fuel oils and the measures necessary to mitigate said risks, have decided to make this information available to the ship crew members who are actually responsible for such operations.
The purpose of this booklet is, therefore, to provide ship crew members on board going to bunker and actually use compliant fuel oils with information focusing on the "compatibility" and "cold flow properties" of such fuels as well as the risks associated with such fuels and the measures to be taken to mitigate such risks.
In addition, relevant recommendations and product leaflets for mitigating the potential risks of compliant fuel oils have been provided by several chemical makers pertaining to the sludge dispersants and sludge solubilizers that are referred to in this booklet. These materials are added as attachments to this booklet.
In cases where HSFO (High Sulphur Fuel Oil) has been stored in a ship’s fuel oil storage tank before compliant fuel oil is loaded in the tank, on the other hand, sludge may precipitate on the bottom part of the tank or on the tank walls. In such cases, if a compliant fuel oil was loaded into the tank without due considerations, then it might lead to operational problems in the fuel oil purifiers, filters and engines, or sulphur
content of the mixed fuel oil in the tank might exceed 0.50%.
In this regard, the development of a plan to manage fuel oils within a sulphur content of 0.50% or lower, including the preparation for fuel oil change-over by tank cleaning, is recommended; for example, the Ship Implementation Plan referred to in the IMO’s Guidance on the development of a ship implementation plan for the consistent implementation of the 0.50% sulphur limit under MARPOL Annex VI (MEPC.1/Circ.878).
As possible countermeasures to sludge precipitating in storage tanks in which HSFO has been stored, cleaning the tank, dosing sludge dispersants multiple times before loading compliant fuel oils, loading LSMGO (Low Sulphur Marine Gas Oil) or dosing sludge solubilizers are things to consider. While it is understood that a number of ship operators have already developed such plans, those who have yet to do so should refer to relevant recommendations and leaflets provided by several chemical makers that are attached to this booklet.
Finally, since each ship has its own specific design, specification and operational condition, it is necessary for the shipping company to decide the preventive measures suitable for each ship based upon the technical information provided by the shipyards, manufacturers and chemical makers.
Click on below image to download the Guidance paper: