Fractional Distillation of Petroleum
Separate crude oil into useful fractions based on boiling point ranges
CRUDE OIL IN
FURNACE
~40°C
~400°C
Column Temp
Decreases upward
Click on a fraction, outlet, or item in the Fraction Monitor to see detailed properties.
Fraction Monitor
Property Trends
Downwards
Boiling Point ↑
Viscosity ↑
Flammability ↓
C-atoms ↑
HKDSE Tip
- Physical process:Fractional distillation of crude oil is a physical process because components are separated by boiling point ranges without forming new substances.
- Property trends:As carbon chain length increases: boiling point ↑, viscosity ↑, flammability ↓, and colour darkens.
- Condensation:Vapours rise up the column and condense into liquids at trays where the temperature is below their boiling points — e.g. liquid bitumen collects near the bottom (~400°C).
- Fuels:Combustion of hydrocarbons releases heat energy, which is why lighter fractions (e.g. refinery gas, petrol) are mainly used as fuels.