SHIPS FUEL CONSUMPTION A TOPIC OF DISCUSSION

INTRODUCTION  :

Fuel oil is obtained from crude petrolium which is composed of thousands of different hydrocarbon compounds. Hydro-carbons are organic compounds asso­ciated with animal or vegetable life.

Marine fuel oils are extracted from three main types of hydrocarbons they are Paraffins, Napthenes and Aromatics.

PARAFFINS : Chain type 'saturated' hydrocarbons exhibiting a single co-valent bond structure. The general formula applying to the group is CnH2n+2 (maximum n=70)

NAPTHENES: Clyclic type 'Saturated' hydrocarbons exhibiting a single co-valent bond. The general formula for the group is CnH2n. there must be at least three carbon atoms for a cyclic structure and they are named with a prefix cyclo.

AROMATICS : Cyclic structure but differ from the napthenes by virtue of their 'Unsaturated' bond structure. The parent member of the aromatic group is Benzene (C6H6) exhibiting three double bonds (CnH2n-6)

The double bonds are weak spots in the molecular structure, i.e. it is easily attacked by many chemicals. A typical attack is oxidation, this is important when considering the hydrocarbon as the base stock for lubricating oils

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