Fuel Oil is a liquid that remains as a residue when distillate fuels are removed from crude petroleum during refining. The impurities in the original crude are concentrated in the residue giving rise to a number of difficulties in the combustion of residual fuel oil. Fuel Oil is rich in sludge-forming unsaturates and sulphur, ash and moisture. The presence of paraffinic and asphaltic particles in the fuel oil also causes improper atomization and prevents efficient burning of fuel oil. Incomplete combustion results in excessive formation of soot and smoke.

Fuel Oil is a liquid that remains as a residue when distillate fuels are removed from crude petroleum during refining. The impurities in the original crude are concentrated in the residue giving rise to a number of difficulties in the combustion of residual fuel oil. Fuel Oil is rich in sludge-forming unsaturates and sulphur, ash and moisture. The presence of paraffinic and asphaltic particles in the fuel oil also causes improper atomization and prevents efficient burning of fuel oil. Incomplete combustion results in excessive formation of soot and smoke.