Distillation

Distillation separates each crude oil into fractions known as light naphtha, medium naphtha, heavy naphtha, light oil, heavy oil and residuum according to their boiling points. Light, medium and heavy naphthas have octane numbers of 90, 80 and 70 respectively. The fractions into which one barrel of each type of crude splits are given in the table:

 

Light

Medium

Heavy

Light

Heavy

 
 

naphtha

naphtha

naphtha

oil

oil

Residuum

Crude 1

0.1

0.2

0.2

0.12

0.2

0.13

Crude 2

0.15

0.25

0.18

0.08

0.19

0.12

N.B. There is a small amount of wastage in distillation.