Fuel testing facility Viswa Lab has issued a white paper concerning the testing and use of VLSFO blended fuels since the beginning of this year when the IMO 2020 regulation was introduced.
The lab has analysed thousands of fuel samples from all over the world and says that the blending has caused stability and compatibility problems for crew on board ships.
The list of issues caused include cold flow properties, high acid numbers, poor ignition and combustion properties, high cat fine content, low viscosity, the presence of unusual components in fuels and long-term storage issues.
According to Viswa Lab the test results can vary dramatically even when fuels are made in the same port by the same supplier. This has caused a number of issues including purifier sludging, waxing and fuel solidification, and in some cases there have been reports of high cylinder war and piston ring failures.
Most reported cases, however, are concerned with the instability and compatibility issues caused by the blending which chokes filters and leads to sludging of fuel, said the lab.
Viswa Labs suggests crew do not mix fuels if possible, but if this is unavoidable to make sure the receiving tank is as empty as possible before taking on new bunkers and suggests using new methods and algorithms to predict fuel stability.
