Marine fuel and its availability, safety, quality, variance, switchover and enforcement has dominated conversations in the shipping industry in recent years as it looked to switch over to using 0.50% very low-sulphur fuel oils (VLSFOs). Since the IMO announced fuel emission limits in 2008 with MARPOL Annex VI regulation 14.4.3, the industry showed scepticism about how this could be achieved. However, two months since its mandatory compliance on 1 January 2020, the industry has shown its well-known resilience and generally concluded ‘so far so good’ without any major issues. Although it’s still very early to fully assess the impact of this change, based on initial data we can objectively assess some concerns raised while others will likely resolve themselves.
Decline in high-sulphur fuel oils
Since August 2019, in fuel analysed by LR, we have seen a continuous decline in high-sulphur fuel oils (HSFO) from 85% to just under 10%. The gap is mainly filled by higher viscosity VLSFOs, which differs to an initial market anticipation that most fleets would switch over to distillates rather than opt for VLSFOs due to concerns around quality. With some 100 countries, 400 ports and over 350 suppliers already delivering VLSFO around the world, the availability of VLSFO looks promising. This is perhaps unsurprising with the higher price margins that VLSFO can command.
While availability of VLSFO looks promising, the situation is very different when it comes to the quality of fuels available, both in terms of the wide variability in composition and the rise in the number of off-specification fuels. On average 4% of HSFO fuels were off-specification and this number has been almost consistent over the past decade. Furthermore, 80% of these off-specification results were due to a slight variance in viscosities: water content, densities, catfines and stability of fuel. These issues could mostly be managed by the ships; with slight adjustment to fuel treatment systems, these fuels would be suitable to be consumed onboard ships safely.
When comparing the HSFO off-specification data with that of VLSFOs, it appears that 80% of off-specification fuels are mainly due to two critical parameters – sulphur content and the stability of fuels. The high numbers of VLSFO with sulphur above the limit is worrying. However, given we are only a couple of months into 2020, the slight sulphur exceedance could be due to cross- contamination attributed to the use of the same supply chain. With time, these issues are expected to decrease. In the first few months of 2020, we’ve already seen a sharp decline in the sulphur exceedance incidents from 8% to just over 2% of total VLSFOs supplied. If we compare this to 2018 data, 0.10% fuels for Emission Control Area operations had a non-compliant rate of around 4%.
However, the high sediment results in VLSFOs remains a concern. Due to its criticality and high volume of cases LR has tested, the class society has issued three bulletins to alert clients about the VLSFO stability issues. High sediments could be due to dirt in fuel or inherent instability of the fuel. Fuels with high sediments tend to cause sludging and filter-blocking problems during use. The data is also indicating that the VLSFOs are more paraffinic in their composition and so by nature they have limited inherent stability, due to their increased thermal sensitivity. In addition, we have seen a number of ships reporting unusual sludging and filter blocking issues when using these fuels.
Even though we have completed the transition, there is still some normalising yet to be achieved and with this high trend of such critical parameters, we are anticipating that the supply chain will take corrective actions, otherwise the frequency and intensity of off-spec claims would make it difficult for suppliers to continue.
Crew awareness: viscosity and density levels
Our VLSFO data shows the viscosities of these fuels ranging from 3 centistokes (cSt) to 500 cSt, with 75% between 20-180 cSt. Similarly, the densities vary between 840 – 1010 kg/m3. These variances in viscosities and densities, potentially between each bunker, demand a better emphasis on ensuring a greater knowledge of the fuel loaded and checking whether any changes in the fuel system heating or cooling are required from storage to combustion. Based on client feedback received to date, it seems that the majority of the ships tested have enacted suitable preparations of their fuel systems and ensured their crew’s awareness on the importance of addressing these variances. Importantly, this has paved the way for a relatively smooth implementation of these VLSFOs.
VLSFOs have a higher proportion of waxier components in their composition, which has increased the pour point of such fuels. As a result, this has increased the overall average pour point of the fuels. Some 85% of HSFOs had a pour point less than 6°C. However, only 14% of VLSFOs have a pour point of less than 6°C. For instance, a large number of VLSFOs have a pour point between 15-30°C (as shown below).
This overall higher pour point has resulted in operational difficulties, specifically in colder ambient conditions, for ships that did not consider or include these issues in their risk assessment. This has prevented some ships from being able to heat fuel, which has caused fuel solidification in tanks, making it difficult for ships to re-liquify fuel without going through a lengthy and costly process.
Crew awareness: handling temperatures
It’s well-known by the industry that lower densities and higher pour points are indicative of VLSFOs being more paraffinic than HSFOs. This is also indicative of the higher percentages of wax components in the fuels, which require more attention to the storage and handling temperatures.
This characteristic is particularly important where the viscosities of the fuel are less than 80 cSt @ 50°C. To treat such fuels, purifier manufacturers recommend lower temperatures. However, with some waxes having a high melting temperature, if these temperatures are not reached the wax can fall out during purification, causing excessive sludging.
For clear and bright distillates, the Cold Filter Plugging Point (CFPP) can address temperatures that a set filter size will start blocking. However, there is no test for darker, lower viscosity, more paraffinic fuels. LR’s FOBAS team has developed a test method called Sediment Waxing Precipitation Point (SWPP), which gives an indication of the temperature that needs to be maintained to avoid issues with wax crystals forming sludge deposits during purification. Results from tested data suggest that on average an approximately 20°C increase in purification temperature is required for fuels with a viscosity at 50°C of 20-80 cSt. According to our data, while more than 85% of marine fuels have switched over to VLSFOs, the level of reported problems has been much lower than initially anticipated. This is partly due to shipping’s determined approach to embrace this change through preparation, knowledge gathering, sharing and joint industry initiatives and collaboration between a variety of industry stakeholders.
The VLSFO issues highlighted in this article were anticipated and should have been captured within a ship’s specific Ship Implementation Plan (SIP). This would have included a thorough risk assessment to identify any ships-specific constraints and ensure these were covered in the bunker purchasing clauses. For those ships experiencing difficulties in handling these wider variances in quality of VLSFOs, we suspect this is partially due to lack of preparation, forward planning of the new bunkers and a poor understanding of the ships’ system capabilities.
The issues raised demonstrate the greater need for training. Throughout 2019 and this year, LR has provided extensive classroom-based training and an online course to help the shipping industry implement this step change smoothly and safely. Finally, although the VLSFO is available on the market today and we did not expect to see the same level of unanticipated quality variance/issues, it is still early days, so a cautious approach is still required and SIPs should continue to be maintained by crew.
- Procurement: select suppliers carefully. It’s important to assess how much control suppliers have on the bunker supply chain, both up and downstream. The LR Fuel Finder can assist shipowners and crew with understanding fuel quality available across the globe.
- Stakeholders: based on the risks identified in SIPs, shipowners should be prescriptive with their bunker quality T&Cs to ensure ship constraints, such as minimum preferred viscosity and pour points. Discussing the ship’s requirements with other stakeholders such as charterers, suppliers can help to match the product quality to the ship’s requirements.
- Bunker information before supply: we would encourage shipowners to seek full standard quality data from suppliers. This information will help the decision-making process: deciding on bunkers, designating tanks, load quantity etc.
- Feedback: to help the wider industry build knowledge on issues with VLSFOs, and prevent further issues occurring and reduce operational problems, we would encourage shipowners and crew to share their experiences by emailing us at firstname.lastname@example.org. Operational issues/observations should also be discussed with suppliers and fuel testing providers. This will help accelerate industry learning and understanding about formulations of VLSFOs, which will also assist suppliers to tighten scrutiny on the blend components, improving the overall integrity of the bunker supply chain.
Find out how our world-class fuel specialists can help you validate fuel quality and quantity and support you to manage fuel safely and optimise performance on our fuel testing page.
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