GCMD’s six-month B24 trial shows same engine performance as VLSFO

In Singapore, the Global Centre for Maritime Decarbonisation (GCMD) released its Project LOTUS (Long-term impact of continuous use of biofuels on vessel operations) report. Launched in partnership with NYK Line on May 9, 2024, the six-month trial onboard a pure car and truck carrier (PCTC) assessed the impact of continuous use of a B24 blend, comprising 24% fatty acid methyl ester (FAME; also known as biodiesel) with very low sulphur fuel oil (VLSFO), on engine performance and operations of the fuel oil delivery systems.

Until now, the impacts of long-term use of biodiesel on main and generator engines, fuel storage and supply systems, and other shipboard components have not been comprehensively evaluated. Additionally, operational protocols for fuel conditioning, onboard storage, and comprehensive inspection checklists remain limited.
Project LOTUS addresses this gap directly by implementing a structured monitoring approach to track fuel and lubricant quality at key sampling points across these systems, and inspect engine and fuel system components throughout the trial. This work is especially pertinent following the International Maritime Organization (IMO)’s approval of its net-zero framework, positioning biofuels as an increasingly valuable near-term decarbonisation measure. Shipowners can increase the biofuel content of their blends to reduce penalties under escalating Greenhouse Gas (GHG) Fuel Intensity (GFI) targets, meet compliance requirements, or generate “surplus units” for trading or future use.

Project LOTUS involved extensive laboratory testing of 94 fuel and 91 lubricating oil samples, alongside detailed engine inspections and measurements during the vessel’s scheduled post-trial dry dock. The main and generator engines, which ran on B24 for 2,888 and 1,813 hours, respectively, performed comparably to when they operated on VLSFO.
Key observations confirmed no excessive sludge in fuel injection valves, no scratches in fuel injection pump plungers, and no liner or piston wear beyond original equipment manufacturer (OEM) specifications. Scavenge drain and engine oil analyses also showed no excessive wear elements.
While the acid value of B24 blends increased 2.5-fold after six months of storage, the fuel quality remained within ISO 8217 specifications. No microbial growth was observed in fuel samples.
With these findings, OEMs confirmed engine and hardware compatibility with long-term B24 use, with no significant impact on operational costs, provided appropriate maintenance and handling practices are followed.