chemical science

Fuel Oils

Fuel oil (also known as heavy oil, marine fuel or furnace oil) is a fraction obtained from petroleum distillation, either as a distillate or a residue.

In general terms, fuel oil is any liquid fuel that is burned in a furnace or boiler for the generation of heat or used in an engine for the generation of power, except oils having a flash point of approximately 42 °C (108 °F) and oils burned in cotton or wool-wick burners. Fuel oil is made of long hydrocarbon chains, particularly alkanes, cycloalkanes, and aromatics.

The term fuel oil is also used in a stricter sense to refer only to the heaviest commercial fuel that can be obtained from crude oil, i.e. is heavier than gasoline and naphtha.

Although any reputably refiner will do their best to provide on-specification fuel oil at source, the later blending of these fuel oils or addition of so called ‘cutter stock’ materials of lesser quality before delivery can lead to quality issues while in use. Likewise, storage tank and line contaminants or improper use of additives at the end use facility can lead to issues.

Problems with fuel oils not only bring about poor combustion and possibility for pollution, they can also damage machinery and cause delays when operations must halt. Depending on circumstances and if not properly managed, such issues can lead to claims in excess of a million pounds or more.

On a land site or on board a ship, our engineers can assess the management and handling of the fuel oil, and our bunker (fuel quantity and quality) surveyors, available in many parts of Asia and Europe, can take representative samples to be sent to a laboratory of choice for testing.

Our scientists can help with standards and methodology, and can interpret the results of laboratory testing. Where machinery damage is found, our metallurgists can sample, examine and report on the possible causes of such damage, and whether or not it is fuel related.

Laboratory Analysis

At our own fuel laboratories, AMA technicians and scientists can carry out a range of tests including:

  i. Test parameters included in the standard ISO 8217, Table 2 

  • Sulphur
  • Density
  • Viscosity
  • Water
  • Flash Point

  ii. Additional tests (not included in the standard ISO 8217, Table 2)

  • Stability and Compatibility
  • Asphaltenes
  • Xylene equivalence
  • Toluene insoluble matter
  • pH
  • Microbial contamination

With our deep local knowledge, we can also help with the selection of other appropriate testing facilities and advise on possible costs.

Case Study: Correction of Fuel Oil to Permit Use

A vessel received a delivery of more than one thousand tonnes of IFO 380 fuel oil and RMG 380 marine gas oil, which when tested by GCMS CRA was declared off-specification for use on several points, with elevated levels of methylstyrenes and 4-cumylphenol additionally stated present (the latter suggesting waste chemical material had been added).

The owner of the vessel required the fuel to be offloaded, tanks cleaned and additionally held our client (who had supplied the fuel) to account for losses. They promptly set about building a case to claim for a range of financial damages, including those of a direct and consequential nature, as well as physical (machinery) damages.

AMA were instructed only after the fuel had been placed to use, and then found unsuitable by laboratory testing. Our clients were already under huge pressures to offload the fuel and were facing claims from up and down the contractual chain.

The fuel oil had been tested in accordance with ISO 8217:2005 with some additional ‘in house’ tests of the laboratory for such things as asphaltenes, reserve stability number (RSN), xylene equivalence (XE), stability, total acid number (TAN) and GCMS in accordance with paragraph No.5 of ISO 8217:2005.

The expert fuel team at AMA were able to assess each separate laboratory finding sequentially for industry and legal compliance, demonstrating it was stable and “homogeneous blends of hydrocarbons derived from petroleum refining”,  “free from inorganic acids and from used lubricating oils” (KOH g), with compliant levels (ppm) of  zinc, phophorous and calcium.

The single item that was found to be above expected limits, namely the 4-cumylphenol, was demonstrated to not be of a level proven to cause machinery damage or other problems, and as such the fuel oil was suitable for continued use.

To appease any concerns of the vessel owner still further, AMA were able to provide a practical framework of chemical additives, onsite purifying and burn monitoring that allowed the fuel oil to be used. This removed instantly the threat of litigation and the expected costs of more than £1 million GBP.

AMA Provided: –

  • Petrochemical scientists (oil experts)
  • Chemical scientists (general chemical experts)
  • Mechanical engineers (operational experts)

Why not give us a call now to see how we could help you

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