Ships Report Major Engine Issues After Using Cashew Nutshell Marine Biofuel

Ships operating in Singapore and Rotterdam have encountered significant engine problems after using biofuel made from cashew nutshell liquid (CNSL), according to a report by fuel testing agency CTI-Maritec.

The affected ships reported issues such as clogged filters, injector failures, fuel sludging, and turbocharger corrosion.

CTI-Maritec’s analysis of the fuel samples revealed high levels of compounds like cardol, cardanol, and anacardic acid, indicating that the fuel had been blended with CNSL from undisclosed or poorly regulated sources.

The agency highlighted that CNSL is highly acidic and reactive, making it unsuitable for use in marine engines.

While CNSL is seen as a low-cost, renewable fuel option, it has not been approved for marine use by any recognized standards.

CTI-Maritec emphasized that using such untested biofuels contradicts International Maritime Organization (IMO) guidelines, which mandate the use of established and well-tested fuel components.

In response, the Maritime and Port Authority of Singapore (MPA) reaffirmed that all bunker fuels must comply with ISO 8217 standards. They also mentioned recent enhancements to their fuel testing protocols to prevent similar issues in the future.

Earlier this year, cashew nutshell biofuel was tested in a controlled project by a Norwegian shipping company, but the recent incidents have brought forward the risks of using CNSL blends in regular operations.

CTI-Maritec advises shipowners to stick to approved biofuels, such as FAME-based options or hydrotreated vegetable oil, to ensure safe and reliable engine performance.

Reference: Reuters

Source: Maritime Shipping News