Warning Against Using Cashew Nutshell Liquid Biofuel for Marine Fuels

Fuel suppliers and shipping companies are exploring various non-FAME biofuels, but a leading testing firm, CTI-Maritec, has issued a warning against using Cashew Nutshell Liquid biofuel. The Singapore-based company found high concentrations of harmful compounds in fuels from undisclosed sources or production processes during their testing. Ships fueling in Singapore and Rotterdam have reported operational issues such as fuel sludging, injector failure, and system deposits after using VLSFO samples that were found to be blended with Cashew Nutshell Liquid.

CTI-Maritec conducted extensive Gas Chromatography Mass Spectrometry testing on fuel samples from vessels experiencing operational issues. They discovered high concentrations of compounds indicating the presence of Cashew Nutshell Liquid blended from undisclosed sources or production processes. The firm advises shipowners against using 100 percent CNSL as a marine fuel or as a blending component, contrary to IMO guidelines on fuel oil quality for ships. Accepted biofuels like FAME-based biofuels and Hydrotreated Vegetable Oil are recognized by equipment manufacturers, class societies, and flag administrations.

Cashew Nutshell Liquid is a non-FAME biofuel derived from the cashew nut industry, acting as a low-cost renewable fuel. However, CTI-Maritec warns that CNSL is highly reactive and less stable due to its high iodine value, making it corrosive and prone to post-combustion deposits. They recommend against using unestablished bioproducts in marine diesel engines and suggest testing blend compounds to understand their properties and suitability for bunker products. Understanding how these compounds interact with other components is crucial to ensuring safe and efficient fuel usage.

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