Recently, Skuld has seen several vessels reporting bunkered fuel that is on specification as per ISO 8217 parameters. Still when advanced tests were carried out, Gas Chromatography MassSpectrometry  showed a high presence of hydrocarbon compounds, phenolic compounds, and other alkylresorcinol derivatives.

Most of these bunkered fuels stem from Southeast Asia, particularly in Singapore, Hong Kong and Malaysia. The results mentioned above are similar to those reported by fuel testing laboratories, i.e., that it include levels of shale oil components. Some bunker suppliers may intentionally supply blended, low-quality marine fuels amid sharply rising bunker prices due to the war in the Middle East.

Some of the GCMS reports we saw, which contained hydrocarbon compounds like dihydro-dicyclopentadiene and indene, had a concentration level between 5,000 ppm – 14,000 ppm, and Alkylresorsinol concentration between 4,700 ppm – 6,000 ppm. We have previously seen very high concentrations of such compounds,  which are commonly associated with Estonian shale oil, and in 2019, we saw a number of VLSFO fuels from the ARA region containing such compounds.

Whilst shale oil is not considered a contaminant and is an acceptable blend component under the ISO 8217 standard, at high concentrations it can cause operational challenges onboard as the presence of hydrocarbon compounds, phenolic oxygenated compounds, and other alkylresorcinol derivatives is not typical of marine fuels.

There is a risk that these compounds may result in sludge formation, filter and purifier fouling, and fuel injection system issues, and that poor engine performance may be experienced, but this is not certain, and in general, most vessels using fuels with these unusual compounds do not experience problems. A risk assessment should be performed, and the GCMS report must be taken as a warning.

When GCMS is performed as part of a troubleshooting exercise in which the vessel has reported problems, we can link the problems and the detected chemical compounds. In case the fuel is not free from material that renders the fuel unacceptable for use in marine applications because the fuel contains any added substance or chemical waste that jeopardises the safety of the ship, adversely affects the performance of the machinery or is harmful to personnel or contributes overall to additional air pollution, then the fuel does not meet the requirements of clause 5 of ISO 8217.

Skuld advises its members and assureds to always perform due diligence when ordering or procuring bunkers and follow precautionary measures when handling this kind of fuels.

• It is very important always to conduct a vetting procedure when selecting a good bunker supplier. Clarification should be sought from their supplier regarding the blended component used.
• A fuel analysis should always be carried out before using the bunkered fuel. As these phenolic compounds cannot be detected in the standard ISO 8217 test, an extended advanced GCMS test from a reputable fuel laboratory is recommended.
• Perform correct fuel handling and enhanced monitoring of the fuel treatment machinery onboard, such as purifiers and filters.
• Good record keeping should be carried out, such as tank sounding records, fuel transfer and consumption, correct temperature settings in the fuel tanks, purifiers and main and auxiliary engines.
• Fuel System Check is recommended to check the fuel quality of the fuel entering the engine.

Source: Skuld