Project LOTUS: Long-term impact of continuous use of biofuels on vessel operations

To gather long-term operational data to guide use of biodiesel onboard vessels

• Evaluate long-term vessel performance using B24 used cooking oil (UCO)-derived FAME in very low supphur fuel oil (VLSFO)

• Identify maintenance needs and operational impacts from extended biodiesel use

• Assess fuel quality and variability onboard vessel

• Capture user insights through interviews

Key findings and observations

• Laboratory testing and sample analyses: During this project, extensive laboratory testing, comprising 94 fuel and 91 lubricating oil samples, along with engine inspections and measurements, confirmed that the continuous use of a B24 blend onboard the nominated vessel did not adversely impact the vessel’s engine performance and fuel delivery system.

• Engine performance monitoring: The main and the generator engines monitored ran for 2,888 and 1,813 hours, respectively, and performed comparably on B24 and VLSFO.

• Engine component inspection: There was no excessive sludge in fuel injection valves, no scratches in fuel injection pump plungers, and no liner and piston wear beyond those specified by the original equipment manufacturers (OEMs).

• Scavenge drain and oil analyses: Scavenge drain and engine oil analyses also showed no excessive wear elements.

• Fuel storage and quality: Despite a 2.5-fold acid value increase in the B24 blends after six months of storage, the fuel quality remained within ISO 8217 specifications; its use did not impact engine performance. No microbial growth was observed in fuel oil samples.

• Engine and hardware compatibility: With these findings, OEMs confirmed engine and hardware compatibility with their long-term use of B24 blends, with no significant impact on operational costs, provided that appropriate maintenance and handling practices are followed diligently.