Blended Fuels: "Less Sulfur, More Bugs" Warning

by Ship & Bunker News Team
Monday November 11, 2019

The quality of some blended compliant fuels could be compromised, a monitoring agency has said.

According to Canada-based microbial monitoring specialist Luminultra, the increase in biodiesel in marine gasoil and the blending of high sulfur fuel oil with recovered distillates is behind the concern.

"As biodiesel has a high water content, these new [IMO2020 compliant ] fuels can be nutrient-rich breeding grounds for microbiological growth," LuminUltra's business development director Patrick Taylor said.

And he added that there are "real risks, real safety concerns".

These centre on the capacity for biodiesel/diesel blends to absorb water where the presence of water in fuel oil is conducive to microbe growth.

While there is still a lack of information on water absorbance in biodiesel/diesel blends, research has shown that at constant relative humidity, biodiesel absorbed 6.5 times more moisture than diesel.

"If compliant fuels are not regularly monitored for their microbiological content, then, at the very least, biofilm will form and clog up the fuel filters," Taylor said.

With a range of new fuel blends coming to market to meet the IMO2020 rule of the sulfur content of bunker fuel, the stability and effectiveness of these 'new' fuels is being questioned in some quarters.

However, others say that blended bunker fuels have long been a feature of the global market.