Separating Crude Oil - Crude Oil, Hydrocarbons and Alkanes

Introduction

• Crude oil is a finite resource.
• It is used to produce petrol and other fuels through fractional distillation.
• Cracking is a process used to convert long alkanes into shorter, more useful hydrocarbons.

Fractional Distillation

• Definition: A process where a mixture (like crude oil) is distilled, and evaporated components are collected as they condense at different temperatures.
• Purpose: To separate crude oil into simpler, more useful mixtures.
• Process:
  • Heated crude oil enters a fractionating column, which is hot at the bottom and cooler at the top.
  • Vapors rise through the column and condense when cooled enough.
  • Liquids are collected at different heights based on their boiling points.

Characteristics of Hydrocarbons

• Different hydrocarbons have different boiling points due to varying intermolecular forces.
• Small Hydrocarbon Molecules:
  • Have weak intermolecular forces.
  • Low boiling points.
  • Remain as gases and leave the column.
• Long Hydrocarbon Molecules:
  • Have strong intermolecular forces.
  • High boiling points.
  • Condense and leave the column as hot liquid (e.g., bitumen).

Crude Oil Fractions

• Definition: The different useful mixtures obtained from fractional distillation are called fractions.
• Characteristics:
  • Each fraction has similar boiling points.
  • Represent parts of the original crude oil.

Remembering Fractions

• Mnemonic: "Lazy Penguins Keep Drinking Hot Beer" to remember the names of the fractions.

For further exploration, the guide offers sections on other associated topics such as Alkanes, Cracking and Alkenes, and more organic chemistry principles.