CMT urges biodiesel blend monitoring
As the maritime industry looks to meet decarbonisation goals, biofuels, ranging from 10% biodiesel to 100% pure fatty acid methyl esters (FAME), are becoming more widely used.
However, CMT warns that without proper oversight, these fuels can cause fuel instability, corrosion and mechanical wear, driving up maintenance costs and operational risks.
“Biofuels do offer sustainability benefits, but without the right monitoring and management, they can result in long-term engine damage, significant downtime and costs,” warned David Fuhlbrügge, CMT’s co-managing director.
“Operators must actively monitor fuel quality to prevent issues that could compromise engine efficiency, reliability and compliance.”
New IMO emissions targets and the ISO 8217:2024 fuel standards have paved the way for higher biofuel content, but research by DNV shows that biofuels’ solvent-like properties can dislodge tank residues, clogging filters and separators.
Additionally, biofuels’ higher acidity can accelerate corrosion, requiring lubrication adjustments with higher BN (Base Number) lubricants to protect engine components. The fuels’ ability to absorb water also encourages microbial growth, leading to fuel degradation.
“Marine engines designed for conventional fuels will require operational adjustments to handle high biofuel concentrations, while fuel heating and purification systems should also be optimised for biofuel properties,” continued Fuhlbrügge.
Fuhlbrügge also warns that performance could differ when using biofuels. “The low energy density of some biofuels could also mean more fuel is required to maintain voyage range,” he said.
CMT has reported growing interest in its test kits, especially from the cruise industry, which is increasingly adopting biofuels to meet sustainability targets. To mitigate risks, CMT advises shipowners implement a comprehensive testing regime, including initial fuel analysis, periodic testing and continuous monitoring.
“It’s not simply about reducing carbon emissions, it’s about understanding the complex chemical interactions happening within engine systems when we introduce higher biofuel percentages,” concluded Fuhlbrügge.
