Crude oil is a mixture of hydrocarbons. The refining of crude oil produces fractions which are more useful to us than crude oil itself. Each fraction is composed of hydrocarbons which have boiling points within a specific range of temperature. The separation is carried out in a fractionating column.
a. Fractional distillation is the technique used to separate the fraction
b.
A: Refinery gas
B: Gasoline(petrol)
C: Naphtha
D: paraffin (Kerosene)
E: Diesel Oil
F: Fuel oil
G: Lubricating fraction
H: Bitumen
c. The crude oil is evaporated and its vapours condense at different temperatures in the fractionating column. Each fraction contains hydrocarbon molecules with a similar number of carbon atoms and a similar range of boiling points.
d. As molecules gets larger, the fractions get less runny or viscous: from gas at the top tower to solid at the bottom. They also get less flammable. So the last two fractions in the table are not used as fuels.
