Crude oil can be categorized as sweet crude and sour crude. Sweet crude contains less than 0.5% of Sulphur. Sour crude contains more than 2.5% of Sulphur. Crude oil must undergo several separation process so that its products can be utilized. This process is called as oil refining.
The difference in boiling points of various elements is useful in separating various components of crude oil.
It is a simple process. We first heat the crude oil. And allow the vapor to condense at different levels of distillation towers. This is known as fractional distillation. And thus various crude oil products are obtained.
These products can be classified into two types. They are refined product and petrochemical product.
Refined product: it contains lot of individual hydrocarbons. Ex: gasoline.
: it contains one or two hydrocarbons of high purity. Ex: benzene.