A new study that evaluated the impact of mixtures of biodiesel with conventional marine fuels such as potential marine pollutants, as well as the effectiveness of the response in the event of accidental spills, explains that the impact on the environment of the spillage of these alternative fuels is not yet exhaustively documented and that, if, since the From an operational point of view, these mixtures represent a solution to reduce emissions from shipping, however their physicochemical properties influence the behavior in the event of a spill. In fact, the behavior in water varies greatly between different biofuels and differs from that of fossil fuels. The document then notes that the techniques spill response services continue to be usable even in the case of spills of mixtures, but it is necessary to adapt them and improve scientific knowledge to effectively manage accidents with these new fuels.

The study was commissioned by the European Agency for Maritime Security (EMSA) at the World Maritime University (WMU) and to the Cedre with the aim of supporting the maritime sector by strengthening planning, preparation and response in the event of a accidents that cause fuel spills at a time when to which the transition to fuels is accelerating alternatives.

In this regard, the study recalls that, among the fuels currently in use, biodiesel blends based on fatty acid methyl esters (FAME), hydrotreated vegetable oil (HVO) and Fischer-Tropsch (FT) are a drop-in solution to short-term, compatible with engines and naval infrastructures and that mixtures such as B20, B30 and B50, used with diesel (MGO) or ultra-low sulphur fuel oil (VLSFO), allow emissions to be reduced without requiring Significant technical changes to ship engines and supply fuel transport and distribution chains.

The study notes that the maritime sector's experience with spills of biodiesel blends, such as FAME or HVO mixed with marine fuels, is still limited and that Many stakeholders and rescuers had direct exposure to these fuels, which indicates a "lack of technical know-how" and the need for training specific to manage such incidents. The document specifies that, However, early research and laboratory studies provide a certain understanding and indicate that biodiesel blends are in different ways, such as conventional diesel fuel, in the event of of leakage: they float on the water and spread, forming surface patches similar to mineral oil. At the same time, have distinctive characteristics: in particular, they evaporate much less (thanks to low vapor pressures) and biodegrade faster than fossil diesel (about four times faster than quickly in favorable conditions). This high biodegradability causes leaked biodiesel to tends not to persist in the environment for long and that large portions can degrade within a few weeks under the action of microbial.

In addition, the study highlights that the acute toxicity of the biodiesel (FAME/HVO) for marine life is five times lower than that of conventional diesel and this suggests that, in the event of a spill, the environmental damage due to acute toxicity would be less severe than an acute oil spill equivalent. If this represents a positive aspect of these alternative fuels, however, the biodiesel's own properties also introduce new Considerations: For example, pure biodiesel is colorless and forms a much thinner patch, which complicates the visual detection and monitoring of spills. The operators cannot rely on the typical glossy appearance black or brown and may need to use sensors or tools to trace a patch of biodiesel.

The study also finds that the consolidated response techniques to oil spills are applicable to oil spills fuel blended with biodiesel. Industry experts and authorities regulatory authorities, in fact, agree that the barriers containment systems, skimmers and other mechanical recovery methods used for marine fuel oil spills should be practically usable even in the event of spills of biodiesel blends.