To assess the extent of mislabelling of biofuels, the Global Centre for Maritime Decarbonisation (GCMD) conducted an analysis of 16 FAME samples obtained from various market suppliers.
As explained, each sample was examined using FAME fingerprinting and compared against the suppliers’ declared feedstock sources. GCMD has developed FAME fingerprinting to help identify the origin of biofuel feedstocks and trace their authenticity within marine fuel supply chains.
FAME, or fatty acid methyl ester, is typically produced from feedstocks containing triglycerides through a process known as transesterification. The fatty acid chains in triglycerides vary depending on the feedstock source, and this variation results in a distinct chemical profile that remains intact after processing.
This chemical “fingerprint” can be used to determine the feedstock’s origin and also offers useful information about the biofuel’s properties, such as cold flow performance and oxidation stability, factors important for its performance as marine fuel.
The findings revealed that approximately one-third of the samples exhibited discrepancies between the declared and actual feedstock origins, as determined by their FAME profiles. Specifically:
- FAME 1–3: Their FAME fingerprints confirmed that they are derived from virgin palm, soy, and rapeseed oils, respectively, consistent with how they are labelled by their suppliers.
- FAME 4–13: Despite being labelled as used cooking oil-derived biofuels, FAME 4, 5, 6, and 10 exhibit fingerprints resembling virgin palm oil, not heat-treated palm oil. FAME 7, 8, and 11–13 exhibit elevated levels of linolenic acid, consistent with palm oil that had been exposed to high heat. FAME 9 comprises fatty acids associated with palm and soybean oils, aligning with the common consumption of such vegetable oils in China. Quantitative analysis of the relative intensities of the signals attributable to each oil indicates that FAME 9 is derived from a mixture of 50% palm oil and 50% soybean oil.
- FAME 16: Although labelled as food waste-derived biofuel, this sample’s FAME fingerprint appears identical to virgin palm oil. This discrepancy warrants a closer look to determine its actual feedstock.
This, according to GCMD, suggests that mislabelling may be a significant and under-reported issue within the biofuel supply chain.
