• It is the process by which crude oil is seperated into and processes into useful forms.
• It is carried out in a plant called the oil refinery.
• Refining of petroleum involves separating crude oil into various components using a technique called fractional distillation.
• In this technique petroleum is heated in a furnace at around 400°C. As it boils, the vapours are introduced to a tall cylindrical column called the fractionating column. The various parts of the fractionating column are maintained at different temperatures decreasing from bottom to top. The oil vapours rise up in the column losing heat. The different components of petroleum cool and condense at different parts in the column according to their boiling points. (components having higher boiling points condense near the bottom of the column and vice versa). Each component is seperated and distilled to make it purer.
Fractionating column
The products of fractional distillation are -
• Petrochemicals - Chemical products derived from petroleum or natural gas. Ex. Toluene, benzene, ethylene, propylene.