Fractional Distillation of Crude Oil

• What is the technique used to separate hydrocarbons in crude oil?

  Fractional distillation
• Why do longer chain hydrocarbons have higher boiling points than shorter chains?

  Because they have more intermolecular forces
• What are the functions of the important fractions obtained from fractional distillation of crude oil?

  • Petrol: used as fuel for cars
  • Diesel: used as fuel for cars
  • Kerosene: used as jet fuel
  • Heavy fuel oil: used to power ships
  • Liquefied petroleum gas: used in camping stoves
• What is meant by the term 'feed stock' in the context of petrochemicals?

  It refers to chemicals used to make other chemicals
• How does the temperature gradient in a fractional distillation column affect the separation of hydrocarbons?

  It allows hydrocarbons to condense at different heights based on boiling points
• What happens to very short chain hydrocarbons during fractional distillation?

  They are removed from the top of the column as gases
• What are the stages of fractional distillation of crude oil?

  1. Crude oil is heated to a high temperature to boil it.
  2. The vapor is fed into a fractional distillation column.
  3. Hydrocarbon vapors rise up the column.
  4. Vapors condense at their boiling points and are removed as liquids.
  5. Remaining hydrocarbons continue to rise and condense at higher points.
• Where does fractional distillation typically take place?

  In large columns found in oil refineries