2019 November 29
Bunker fuel quality issues continue to persist in the industry, even as fuel management is set to become more critical, ahead of the International Maritime Organization's, or IMO, January 2020 low sulfur global marine fuels mandate, sources at an industry event in Singapore said this week.
"In the 1990's marine fuel was just a straightforward product really, it was blended to meet viscosity requirements...fast forward and it is no longer about viscosity," Douglas Raitt, regional consultancy manager at bunker fuel analysis and advisory service firm Lloyd's Register FOBAS, said at a forum organized by the Association of Bunker Industry (Singapore).
"It's about sulfur and when you start blending for sulfur, basically the viscosity and a whole host of other parameters become collateral damage," he said.
Come 2020, shipowners or operators buying the fuel will need to have a greater know-how for understanding what exactly they are going to buy, Raitt said, adding that buying a 0.5% compliant fuel as per the bunker fuel clause will not be good enough.
As a fuel buyer, the shipowner or operator would need to know the machinery onboard the ship and make a bespoke order with the supplier of the fuel being purchased, with parameters like viscosity clearly earmarked, Raitt said.
"If you don't do that the supplier may still give you compliant fuel but it may be completely useless to use in the ship's main engines. That for me is a profound change really," he said.
FOBAS has been testing low sulfur fuel oil with less than 0.5% sulfur for about a year now, and has found the viscosity to vary from as low as that of a distillate to as high as a 500 CST fuel.
"With that kind of variability in mind, you have to know what you are going to order in 2020," he added.
STABILITY, COMPATIBILITY ISSUES
The market is anticipating stability and compatibility issues as many blending recipes are due for release, Nijas Schemnad, technical sales manager at Eurofins, said.
Under normal circumstances, asphaltenes stay stable as these viscous residues are surrounded by saturates, resins and aromatics, and remain suspended in the fuel oil matrix, he said. But when two incompatible blends come together, asphaltenes agglomerate and form a sludge, Schemnad said.
"For the fuel oil user, this is really scary because it can result in loss of propulsion and a lot of other associated operational risks," he said.
Two stable fuels, when blended, can also become unstable, Schemnad said.
Many shipowners and operators are expected to buy low sulfur marine gasoil post IMO 2020.
However, gasoil does not normally undergo a lot of testing. Gasoil will also be used heavily and stored for longer times post IMO 2020, resulting in potential stability and lubricity issues, he said.
"So, ISO 8217/2017 spec has an oxidation stability and lubricity tests, which should be done," Schemnad said.
Gasoil does not typically need heating but has cold flow issues, which means that when the temperature cools down, the oil first reaches the cloud point, then it usually comes to cold filter plugging point and once it reaches that, gasoil ceases to flow, with serious operational implications, he added.
"Hence, cold flow properties ought to be tested and declared by the fuel supplier as per ISO 8217/2017," Schemnad said.
"FAME (biodiesel) content is allowed in gasoil at "de minimis" levels and could result in water retention, microbial growth and corrosion," he added.
THOROUGH FUEL TESTING VITAL
There is an expected increase in bunker fuel quality issues next year because of increased blending due to the 0.5% sulfur cap, Mohana Dass, global bunker quality surveys manager at Lloyd's Register FOBAS, said at the event.
Clients have already started bunkering very low sulfur fuel oils, Dass said.
The compatibility of 0.5% sulfur bunker fuels still remains a challenge. A spot test is only indicates potential compatibility issues, and a full lab test must be conducted to confirm any findings carried out on board, he said.
At times of quality disputes, surveyors must master the art of taking representative samples from ship tanks for tests, he added.