21. Fuels

Fractional Distillation of Crude Oil
  • Petroleum gas: Fuel for cooking
  • Petrol (Gasoline): Fuel in motor cars
  • Naphtha: Feedstock (starting material) for chemical industries
  • Kerosene (Paraffin): Fuel for heating/cooking or jet engines
  • Diesel: Fuel for diesel engines
  • Lubricating oil: As lubricants & To make polishes and waxes
  • Bitumen: For making road surfaces

As fractions get heavier,
  • Boiling point increase
  • Viscosity increases
  • Density increase
  • Flammability decrease
  • Colour darkens

Alternative Fuels
  • As petroleum is a non-renewable resource and its supply is finite, there is an urgent need to conserve the use of petroleum and to find other alternative sources e.g. biomass fuels, hydrogen, fuel cell, solar energy or nuclear energy.

Hydrogen Fuel Cell
  • Is used  to generate electricity using hydrogen from an external source.
  • Hydrogen and oxygen gases are pumped into the electrodes, containing a catalyst.
Advantages of using hydrogen fuel cell:
  • Chemical energy is directly converted into electrical energy which can be produced indefinitely unlike batteries.
  • Water is formed as a product which is non-polluting.
  • Renewable form of energy.
Hydrogen can be obtained by:
  • Electrolysis of water
  • Cracking of large alkane molecules
Advantages of using hydrogen
  • Produces twice as much energy per gram of traditional source of fuel.
  • Burns cleanly forming water which is a non-pollutant.
Disadvantages of using hydrogen
  • Flammable.
  • Has to be transported in liquid state under great pressure and low temperatures.