Lloyd’s Register’s Timothy Wilson discusses the progress the industry is making on reducing sulphur content in marine fuel oils
At Riviera Maritime Media’s recent webinar on two-stroke engines and very low-sulphur fuel oil (VLSFO), Lloyd’s Register’s principal specialist Timothy Wilson spoke about the progress, challenges and concerns the industry is facing as a result of the new regulations on sulphur content in marine fuel oils.
Mr Wilson identified four key aspects that he said owners and operators need to be aware of when using VLSFOs: diversity of fuel formulations; temperature control and fuel heating and cooling; compatibility and forward bunker planning; and lubricant oil management.
The diversity of fuel blends owners and operators have seen in the lead up and early months of the 0.50% sulphur implementation will persist in the future, Mr Wilson said, and will fundamentally change the way operations work. What the array of blends will mean for those using them is a related requirement to account for diversity in temperature control, he said, noting “fuel management is fundamental” with VLSFOs.
According to Lloyd’s Register data, variation increases in the viscosity levels of VLSFOs has meant the past temperature differentials of 50°C for the HSFO can now be “as much as a 110°C between one bunker to another”.
“We are seeing higher pour points, greater energy values, lower density and lower CCAIs”
Lloyd’s Register data shows that VLSFO blends have increasingly higher old flow temperatures, as well. Pour point measurements recorded in the data were several times those of corresponding measurements for HSFOs. Some 58% of VLSFO samples recorded a pour point over 6° (as compared to 18% of HFOs) and 29% of samples were over 21° (against 1% of HSFOs).
Statistics from Lloyd’s Register also show VLSFOs to be predominantly paraffinic. Mr Wilson said: “We are seeing higher pour points, greater energy values, lower density and a lower calculated carbon aromaticity index (CCAIs)”. He added that while some low flashpoints had been picked mainly in the distillate ranges, they were not at the levels initially feared by the industry.
Going forward, Mr Wilson highlighted areas for “proactive fuel management” to ensure improved combustion and lower black carbon emissions. These include forward bunker planning, selection of supplier, knowledge of a fuel before loading, effective temperature control, compliance risk, minimising onboard storage time, and monitoring fuel system and engine performance.
In the current market, with more ships going into lay up, Mr Wilson advised operators who have purchased bunkering fuel to “load it – use it”. For laid up ships, he recommended putting them in monitoring programmes whereby there is a "set point for taking a sample of the condition of the fuel on a monthly basis” to monitor changes.
Up to 15% of respondents at the webinar reported experiencing availability issues with 0.5% sulphur fuels and more than one in three owners or operators said they have had port state control inspectors come on board to check sulphur cap compliance.
Mr Wilson said a review of the current ISO 8217:2017 standard was underway and the next revision is likely to be published in 2023; along with having to accommodate the increasing use of drop in biofuel blends it is anticipated the next revision will be a significant one.
You can view the webinar, in full in our webinar library