Fractional Distillation and Uses of Hydrocarbons

Overview

• Fractional distillation separates hydrocarbons into fractions with similar boiling points.
• Large hydrocarbons have higher boiling points and condense at the bottom of the fractionating column.
• Smaller hydrocarbons condense higher up the column.

Key Fractions and Their Uses

Refinery Gas

• Composed of hydrocarbons with 1-4 carbon atoms.
• Low boiling point; remains gaseous at the top of the column.
• Stored as bottled gas (e.g., propane, butane).
• Used in barbecues and heaters.

Petrol

• Composed of hydrocarbons with 5-7 carbon atoms.
• Vaporizes at low temperatures; easily ignitable.
• Used as fuel in internal combustion engines (cars and vehicles).

Naphtha

• Not directly used as a fuel.
• Source of organic molecules; can be cracked to form fuels or alkenes.
• Alkenes are used to make polymers and plastics.

Kerosene (Paraffin)

• Used as fuel for jet engines and rockets.
• Also used in kerosene lamps for lighting.

Diesel

• Common fuel for cars, vans, and lorries.
• Less volatile than petrol; ignites under compression.

Residue Fractions

• Fuel Oil: Used in power stations and ships.
• Lubricating Oil: Reduces friction, protects from rust.
• Waxes: Used for polishing surfaces.

Bitumen

• Thick, black adhesive.
• Used for road surfaces and as a waterproofing material for roofs.

Importance of Crude Oil

• Over 1 billion cars use petroleum-based fuels.
• Millions of flights annually burn kerosene.
• Significant production and use of plastic products and packaging.
• Bitumen is essential for road construction and maintenance.

Conclusion

• Crude oil is a valuable resource due to its wide range of useful fractions.
• Understanding the uses of these fractions highlights the importance of fractional distillation.