Residual fuel oil, the heaviest oil product (excluding bitumen).

Fuel oil: did you know….??

Residual fuel oil, the heaviest oil product (excluding bitumen), can be seen as what remains after the light products are removed from the crude oil.

The composition of residual fuel oil is typically a residue from e.g. crude oil distillation or from thermal cracking, blended with a cutterstock, typically a gas oil product. From the crude oil distillation an atmospheric, or long, residue is obtained and often referred to as Straight-Run fuel oil. Straight-run fuel oil forms the basis of the Very Low Sulfur Fuel Oil, or VLSFO, with a maximum of 0,5 % sulfur. Next to VLSFO grade fuel oil a High Sulfur Fuel Oil (HSFO) grade is also available and typically obtained from cracking processes (hence: Cracked fuel oil), with a maximum of 3,5 % sulfur. This high sulfur residual fuel oil grade must be used in conjunction with an exhaust gas scrubber system to reduce the sulfur oxide emitted to air.

Residual fuel oil is used as fuel for boilers and furnaces (e.g. at refineries, power plants) and for low speed diesel engines (e.g. shipping and power plants). Alternatively, fuel oil could be used as an additional feedstock for further refining processing (cracking).