London — The collapse in air and road travel has led to jet and motor fuels finding their way into the bunker pool, raising the volatility of all shipping fuels, said Steve Bee, group commercial & business development director at fuel testing firm Veritas Petroleum Services.
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Bee told S&P Global Platts in a video interview broadcast Nov. 18 that when jet, gasoline and diesel are blended with marine fuels, it raises the prospect of lower flashpoints and with it the risk of fire on vessels.
International passenger demand in September was 88.8% lower on the year amid an anemic rebound in the sector, the International Air Transport Association said Nov. 4. Similarly, road travel has also seen a reduction, average road congestion in Berlin, London, Paris, Madrid and Rome fell to 38% below year-ago levels in the week, according to TomTom data on Nov. 16.
The surplus of fuels for air and road transport, which are selling at a low cost, has implications for not just 0.5%S FO, also known as very low sulfur fuel oil, but also high sulfur fuel oil with a maximum sulfur content of 3.5%, and marine gasoil.
"We believe some of these fuels may have bee blended into marine fuels and with them being more volatile than marine fuels they have actually had the impact of reducing the flashpoint of MGO, VLSFO and high sulfur fuel oils," Bee said.
A low flashpoint is a safety hazard for ships. Platts jet fuel assessments reflect standard commercial A1 jet fuel specifications, for which the minimum flashpoint is 38 C. Platts guideline specify 60 C for fuel oil.
17 of the 38 bunker alerts released by VPS in 2020 have been for flashpoint, the company has seen nine such alerts for marine gasoil, five for 0.5%S FO and three for 3.5%S FO, Bee said. "14 of those have occurred during the COVID-19 pandemic," he said.
Higher wax appearance temperature
The prevailing fuel of choice for shipping is 0.5%S FO, this stems from the International Maritime Organization's lower latest sulfur cap on emissions from ships on the high seas, which imposes a maximum sulfur content of 0.5% and which came into effect on Jan. 1, 2020.
As such, 0.5%S FO is a relatively new fuel and the industry is still getting used to it.
One emerging issue is that waxes begin to crystallize at higher temperatures than in the previously prevalent 3.5%S FO, which means the advice ship operators used to adhere to for storage is now of less use, Bee said.
Currently, 99% of pour points are tested at less than 30 C but this may no longer be relevant, Bee said. "We need to look at the wax appearance temperature or cloud point of VLSFOs and at this moment in time 95% of wax appearance temperatures are greater than 30 C," he said.
The average wax appearance temperature is about 21 C above the average pour point now, so the old advice of storing fuel at 10 C above pour point may no longer be relevant, with waxes precipitating at temperatures that are higher than 10 C above pour point, he said.
"At present, about 70% of samples tested by VPS have a wax disappearance temperature of greater than 40 C," Bee said.
A question of temperature and variation
When storing any type of fuel, ship operators must consider its cold flow properties, viscosity and stability, in all of which temperature plays a crucial role. This is how it has always been, but the challenge posed by 0.5%S FO is that its different incarnations have displayed more variation than was typical for specific types of 3.5%S FO.
Lower viscosity presents problems too.
The higher frequency of finding fuels such as jet fuel in 0.5%S marine fuel has been one contributor to lowering viscosity in the new bunker fuel, sources said.
The risk of finding unstable marine fuel unstable increases with declining viscosity, Charlotte Rojgaard, global technical manager for testing firm Bureau Veritas, said during a presentation earlier in November.
Viscosity levels of 0.5%S fuels have been wide-ranging since they appeared on the market, ranging from 2 CST to 600 CST, Bee said. About 86% of samples tested by VPS have a viscosity of less than 180 CST, he said.
Data from Verifuel, Bureau Veritas's marine fuel services program, showed that the average viscosity at Rotterdam in 2020 has ranged between 61 CST and 70 CST and at Singapore between 88 CST and 98 CST.
To see the interview click here: https://plattslive.com/commodity/shipping/#small-dialog_2507