GCMD project affirms B24 biofuel blend can power vessels over the long haul

September 18, 2025, by Sara Kosmajac

The Singapore-based Global Centre for Maritime Decarbonisation (GCMD) has released a new report detailing the effects of continuous utilization of biofuels during ship operations.

The project titled LOTUS (Long-term impact of continuous use of biofuels on vessel operations) was carried out in collaboration with Japanese shipping titan Nippon Yusen Kabushiki Kaisha (NYK Line). The partnership was initiated on May 9, 2024.

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As explained, the six-month pilot was conducted onboard NYK’s pure car and truck carrier (PCTC) that services short-sea routes. The goal was to assess the effect of the use of a B24 blend, comprising 24% fatty acid methyl ester (FAME) with very low sulphur fuel oil (VLSFO), on engine performance and operations of the fuel oil delivery systems.

Per the report, a total of 4,000 metric tonnes of B24 used cooking oil (UCO)-derived FAME in VLSFO was bunkered over four occurrences over six months.

For the pilot, Singapore was designated as the car carrier’s port of call for bunkering. As officials from GCMD have further elaborated, a carrier operating a short-sea route was chosen because of this type of vessel’s need to deploy low-carbon fuels and the fact that the ship tends to take a longer time in ports due to load and offload cargo.

This can disproportionately affect their Carbon Intensity Indicator (CII) rating; however, since biodiesel is considered a drop-in fuel, its use could improve the ship’s CII ‘almost immediately’, the report suggested.

According to GCMD, the impacts of long-term biodiesel utilization on main and generator engines, fuel storage, supply systems and other shipboard components have so far not been ‘thoroughly’ evaluated, while operational protocols for fuel conditioning, onboard storage, and comprehensive inspections remain limited.

It is understood that project LOTUS sought to establish a more ‘structured’ monitoring approach to track fuel and lubricant quality at key sampling points across these systems, while inspecting engine and fuel system components throughout the trial.

Findings of the initiative

As the report shows, the main and generator engines ran on B24 biofuel for 2,888 and 1,813 hours, respectively, and they performed ‘comparably’ when operating on VLSFO.

The most important observations reportedly showed no excessive sludge in fuel injection valves, no scratches in fuel injection plump plungers, and no liner or piston wear beyond original equipment manufacturer (OEM) specifications.

GCMD’s report revealed that scavenge drains and engine oil analyses also did not show any substantial wear elements. On the other hand, while the acid value of B24 increased two and a half times after six months of storage, the quality of the fuel remained within ISO 8217 specifications with no microbial growth detected in fuel samples.

Per GCMD, with these findings, as long as appropriate maintenance and handling practices are implemented, OEMs validated engine and hardware compatibility with long-term B24 use, with no significant impact on operational costs.

“Project LOTUS grounds the conversation around the extended use of biofuels in evidence. Our findings show that they can be deployed safely and reliably, providing a concrete pathway for shipping’s decarbonisation,” Lynn Loo, CEO of GCMD, commented.

“The use of biofuels is one of the key options for advancing the sustainable development of the maritime industry. We hope that the outcomes of this project will offer new possibilities to those considering the adoption of biofuels and help accelerate their broader use in various fields,” Nobuhiro Kashima, Senior Managing Executive Officer of NYK Line, further remarked.

Other testing

As divulged, to complement the pilot, GCMD inspected other vessel operators using biodiesel, too, in order to compare their onboard practices with guidelines issued by classification societies and OEMs.

These inspections concluded that, while OEMs and classification societies tended to take a cautious stance, the vessel operators showed a more risk-based strategy in adopting biodiesel blends by adjusting existing standard operating procedures (SOPs) for VLSFO with recommended technical guidance where possible.

This is said to suggest that, when operators carry out operations in line with such recommendations, biodiesel utilization does not present major issues.

Moreover, the GCMD has finally underscored in the report that, as biodiesel momentum gains more and more traction, ship operators, OEMs and classification societies may need to align on how and to what extent technical guidance should be applied to balance safety with operational realities.