VPS experts advise on low viscosity VLSFOs; pinpoints emerging flashpoint issues to aviation fuels

Experts from international fuel testing and inspection company VPS, backed by experience gained over a year since IMO 2020, engaged the audience during the Fuel Management Challenges – The Year of 2021 & Beyond webinar on Thursday (23 September).

Captain Rahul Choudhuri, Managing Director AMEA, moderated the webinar with supporting panellists Md Harun Rashid, Technical Manager, and George Stanley, Group Technical & Science Manager, offering attendees insights into the latest marine fuel quality trends.

Members of the audience were keen to seek VPS’ technical perspective on marine engine operations with low viscosity Very Low Sulphur Fuel Oils (VLSFOs), amongst other topics, during the Q&A session.

Technical advice on low viscosity VLSFOs

“It is very common for bunker suppliers to deliver low viscosity VLSFOs ranging between 10 to 15 cSt when placing an order for 380 cSt VLSFO,” notes Rashid.

“The bunker buyer can always initiate a challenge to the supplier over viscosity; however, technically there is no issue. In general, we see many cases where engines have operated on low viscosity VLSFOs without any serious problems.”

He explained marine engines are able to use gasoil which has a viscosity of between 2 to 6 cSt; hence, if an engine can consume gasoil, it should technically be able to use VLSFO as a bunker fuel.

“Engine manufacturers typically recommend a viscosity of not less than 2 cSt; so you may not even need to use extra heating for low viscosity VLSFOs which might even save you energy,” he adds.

Consumption of contaminated bunker fuels

A delegate, meanwhile, enquired about the presence of chemicals within VLSFOs and if such foreign material could still be consumed when present within the bunker stem.

Taking reference from the Houston bunker contamination crisis during late-2018, Rashid replied the issue of chemical contamination within marine fuels could not be single-handedly resolved.

“The situation on the ground is we can list out more than 100 components which shouldn’t be in marine fuels and this discussion has been taken to the International Organization for Standardization (ISO) committee; however, we find that the focus is not there anymore,” he said.

“To date, I don’t think there is a situation where bunkers can be bought without chemicals present. The question is how much do you want to run? If it is just minor [chemical] content we do not think there is any issue.”

Additional insight offered by VPS OCM services

Attention to VPS’ Oil Condition Monitoring (OCM) business took centre stage when Singapore bunkering publication Manifold Times poised a question of how the service could be used to work in hand with VPS’ fuel testing operations.

According to George, a scrape down analysis paired with data from VPS’ fuel testing service offers shipowners additional insights of engine operations.

“Instructions on the use of engine oils has changed since the introduction of VLSFOs and OCM services will be able to tell how cylinder lubricants react to different VLSFOs,” he says.

“Cylinder lubricants undergo a significant change in properties when in contact with VLSFOs and we see many scuffing issues originating from this event.

“So even though a particular VLSFO may be safe to consume, it could mean a different story when paired with an incompatible engine oil. From this aspect, our OCM service offers shipowners a peace of mind by offering the complete picture on what’s taking place inside the engine.”

George later identified the emergence of vessel corrosion issues with the recent uptake of biofuels but hesitated to label the event as a trend due to the development being in the “early stage”.

“But an ICP spectrographic analysis test under VPS’ OCM services is able to tell if the corrosion is either fuel or maintenance related,” he hints.

Origin of marine fuel flashpoint issues

The Q&A session concluded with experts agreeing recent marine fuel flashpoint issues at Singapore, Malaysia and its surrounding regions to be stemming from avails in the aviation and automotive sectors.

“Flashpoint issues from VLSFOs and distillates definitely come from blending not being controlled, with the final unchecked products simply being delivered to vessels,” states Rashid, who exclaims VPS has even recorded flashpoint at atmosphere temperature from off-spec bunkers.

He further stressed on the need for flashpoint testing of marine gas oil (MGO).

“Many clients skip testing MGO for flashpoint but it is important to note damage from MGO is often more dangerous and far more damaging,” he informs.

Moving forward, Rashid pointed out current flashpoint issues plaguing the marine fuels sector to be coming from the use of aviation fuels in bunker blends.

“Jet fuel has a very low flashpoint [of a minimum 38°C] with very low sulphur content [averaging 0.05%] and it is common for blenders to use it as a cutter stock to reduce the sulphur level of marine fuels,” he explains.

“Due to Covid-19, there is not a lot of jet fuel being consumed and this has led the material to flow into the maritime sector.”

George, who was also responsible for issuing VPS’ flashpoint alerts, agreed and added the cost of jet fuel has decreased due to the lack to demand – making the material even more attractive to blenders.

“Quality wise, those [aviation] fuels are good and there are also indications marine fuels are also being blended with automotive fuels [which as a flashpoint of a -40°C],” he states.

“Of course, this problem is blending related and we cannot see another other reasons for the change in flashpoint properties.”

Photo credit: VPS
Published: 24 September, 2021