After the implementation of the IMO 2020 global sulphur cap, on 1 January 2020, there have been industry concerns over the uncertainty and potential diversity of the very low sulphur fuel oil (VLSFO) characteristics.
Considering these concerns, the Standard Club published an article regarding to the operational experience on the transition to compliant fuel blends.
Responding to this article, the International Organization for Standardization (ISO) committee in charge of ISO 8217 analyzed at the main characteristics of VLSFO fuel supplied to ships during the period from January to June 2020.
Then it compared this with the quality of high sulphur fuel oil (HSFO) supplied to the ships in 2018 from January to June.
The key findings indicate that 2020 VLSFOs, as compared to 2018 HSFOs, had lower viscosity, lower density, lower micro carbon residue (MCR) and lower calculated carbon aromaticity index (CCAI), higher net specific energy and a higher pour point.
These factors indicate that VLSFOs in general tending towards being paraffinic in nature and having better ignition and combustion properties in comparison with HSFOs
says Standard Club.
Additionally, in comparison to HSFO, VLSFO characteristics show a broader spread of viscosity and generally lower viscosity and density. This, along with the possibility of a higher pour point and other factors, an increased attention to fuel management (storage, treatment, and handling temperatures) is required.
Moreover, the cat fines levels have generally been lower, with fewer samples found off-specm while the lower density and viscosity of most VLSFOs mean that cat fines are easier to remove during normal onboard fuel treatment prior to engine injection.
The ISO is currently in the process of reviewing ISO 8217:2017 standard, taking into consideration the result of this fuel quality review and taking note of continuing trends and feedback from the industry.
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