MARITEC: Presence of Chemical Compounds in VLSFO From Malta

by Maritec
Friday September 6, 2024

In the last few weeks CTI-Maritec has tested multiple fuel oil bunker samples from vessels that have taken fuel/bunkered in Malta and reported operational issues and/or tested to have the presence of high levels of chemical compounds.

Extended Gas Chromatography Mass Spectrometry (GC-MS) testing by ASTM D7845 was conducted for two Very Low Sulphur Fuel Oil (VLSFO) samples, which showed the presence of high concentrations of acetophenone, phenolic compounds (4-cumylphenol, phenol and others), styrene glycol and phenethyl alcohols.

Furthermore, testing by Solid Phase Extraction (SPE) GC-MS technique indicated low levels of bisphenol isomers, fatty acids, long chain fatty acids and dehydroabietic acid. All mentioned compounds are non-hydrocarbons. Our GC-MS analysis also indicated the presence of reactive hydrocarbons like DCPD, Dihydro-DCPD, Styrene and Indene.

The common problems encountered, as reported by the vessels, were sludging, filter clogging and in some instances, fuel pump issues associated with phenolic compounds and phenethyl alcohols.

Due to the high levels of these chemical compounds, the fuels do not meet the general requirement and is considered as off-spec fuel as per clause 5 of ISO8217 and MARPOL Annex VI regulation 18 which states:

"The fuels shall be homogeneous blends of hydrocarbons derived from petroleum refining. This shall not preclude the incorporation of small amounts of additives intended to improve some aspects of performance.

"The fuels shall be free from inorganic acids and from used lubricating oils. The fuel should not include any added substance or chemical waste which:

  1. jeopardizes the safety of ships or adversely affects the performance of the machinery; or
  2. is harmful to personnel; or
  3. contributes overall to additional air pollution."

CTI-Maritec Recommendations

CTI-Maritec recommends to:

  • Closely observe the vessel fuel system/s for signs of filter clogging and purifier sludging and additionally, increase vigilance on the centrifuges to monitor overloading.
  • Increase frequency of their de-sludging cycle depending on the accumulated sludge.
  • Possibly reduce the Mean Time between bowl cleaning of the purifier and fuel system filters.
  • Avoid blending with other fuels, in particular marine diesel and gas oil and also other fuel oil as such mixing may well increase the sediment problem.

Furthermore, at these levels of concentration of chemical compounds present in fuel oil, there is an increased risk of excessive wear to the vessel's fuel pump plunger and barrel assembly. Therefore, it is advised to monitor the fuel pump index closely to check for deteriorating performance. As a back-up, ensure there are sufficient spare seals and plunger barrel assembly to replace damaged units if necessary.

In addition, as a precaution, it is advised to closely monitor the performance of the engines while using this fuel to detect any deterioration of the fuel injection equipment performance and the sealing effect of the piston rings.

This document, however, does not reflect on the overall quality of fuel being supplied in Malta. If you intend to bunker in this region, please request for a Certificate of Quality prior to loading.

CTI-Maritec can assist you with further information on the quality of bunkers tested in different regions. For further information or assistance please do not hesitate to contact us.