LNG and other low sulphur fuel alternatives are getting much attention, but while they may have growing roles as future fuels, uptake will be very limited in 2020. So it made sense for the Bunker Session at CMA 2018 to focus on the type and quality of oil-based fuels we can expect when the global 0.50% sulphur limit takes effect. And while we are on that subject, the message from speakers at CMA 2018 was loud and clear: there will be no delay! The International Maritime Organization is fully committed to the 2020 date so that is what we all have to prepare for.
The first insight into what the fuels meeting a 0.50% sulphur limit will look like came from John R. LaRese, Marine Fuels Technical Advisor, ExxonMobil Marketing & Refining, in a session entitled “The Economic Calculus of 2020” on Tuesday.
He said they will chiefly be refinery residuals (heavy fuel oil) blended with distillates, adding this would work well if you have residuals from refineries running sweet crudes as these will be low in sulphur and not need much blending.
There may also be fuels similar to the new products developed for emission control areas (ECAs) when the ECA limit dropped to 010% sulphur, some of which are based on other refinery streams such as vacuum gas oil. LaRese said these “ECA fuels” are excellent fuels, but that compatibility with residual fuels “is not great” so there was a need to educate ship crews about fuel segregation and management.
Compatibility, stability and wax
Indeed, fuel compatibility is a key area to watch for 2020 as it is widely anticipated that there will be a large rage of different blends on offer, and that many of these may not be very compatible with each other.
“We anticipate a lot of opportunistic blending,” said LaRese, adding that issues with compatibility between fuel batches – limited to around 2% in the past – are expected to increase.
John Stirling, Marine Technical Quality Manager, World Fuel Services, added two more key watchwords to compatibility when he presented in the Bunker Session on Wednesday: stability and wax.
Stirling reminded the audience that no supplier will guarantee that the fuels they supply are compatible with other fuels today either, so this is not new, but ships’ crew need to be aware.
As for 0.50% sulphur blends, if you take typical ECA-compliant marine gas oil (MGO) and blend it with today’s typical heavy fuel oil (HFO), the blend ratio would be about one part HFO to six parts MGO. This would not be a good blend and would often make unstable blends, especially if the MGO is very paraffinic (waxy) and the HFO very aromatic.
The ship’s chief engineer needs to know the viscosity and other key parameters of the fuels they receive, in particular the fuel’s cold flow properties.
Today, ships do not have heated tanks for distillates, but in the future it may be a huge benefit to be able to do that as some of these fuels will need to be heated to remain liquid. The wax, once solid, is a major problem, but if you can keep it liquid it is excellent fuel, Stirling noted.
During the Petrospot Bunker Surgery, Dragos Rauta from INTERTANKO joined the panel and said fuel management would clearly become more complex, and insisted that there must be safeguards against sludging which can cause severe operational problems.
Unfortunately, this is likely to be a problem if ships receive unstable fuels or they mix two incompatible fuels onboard. There is a solution, Stirling said, which is to buy more expensive fuels. But as long as there are residuals in the mix, sludge formation will occur, although there is a parameter in ISO 8217 that protects against it, namely the limit for sediment potential.
2020 and ISO 8217
There has been a reduction in quality issues an ‘bunker alerts’ for residual marine fuel grades since the ECA sulphur limit fell to 0.10% in 2015, Steve Bee, Group Commercial Director, Veritas Petroleum Services said in his presentation. VPS has, however, seen more issues with distillate fuel quality as demand for distillate fuels surged due to the 0.10% sulphur limit.
ISO 8217 parameters still need monitoring, not just for residual fuels but also distillates, where problems may related to low flashpoint, cold flow properties and FAME (bio-diesel) content, he said.
One question occupying many ship operators’ minds is when we might expect a revision of ISO 8217 to take typical fuel properties for 0.50% sulphur blends into account.
LaRese told the panel on Tuesday that the issue isn’t so much about developing a new specification, but rather to introduce a few new caveats to help owners avoid specific pitfalls. One thing that may be looked at is to create a specification that isn’t based on residual and distillate tables, but rather whether the fuel needs heating or not.
Stirling, who sits on the committee updating the ISO 8217 standard, said the next revision would not be ready until maybe 2022, which is too late for the advent of the 0.50% sulphur limit and the various fuels blends likely to come into the market then.
This is why ISO is instead working on producing an interim solution in the form of a publicly available standard (PAS), which is not part of the ISO 8217 standard, but will rather be a guideline that is an addition to ISO 8217 to help the market. The PAS should be available before 2020.
The session entitled “The Economic Calculus of 2020” was moderated by Neville Smith, Director, Mariner Communications, while the CMA Bunker session Chairman & Moderator was Llewellyn Bankes-Hughes, Managing Director, Petrospot Ltd.