Pollutants From Fuels

• When a fuel is burned it releases many gases into the atmosphere. These gases can include:

  • carbon monoxide (CO)
  • This is a toxic invisible gas, and it preferentially binds to haemoglobin in red blood cells instead of oxygen. This reduces the amount of oxygen carried in the bloodstream, causing affected people to feel sleepy or to become unconscious. Severe poisoning can even cause death.
• • carbon particulates (soot, C)
  • This can block pipes carrying away waste gases from an appliance. It will blacken buildings, and it can cause breathing problems if it collects in the lungs. Particulates can also contribute to global dimming, reducing the amount of sunlight that reaches the Earth's surface.
• • sulfur dioxide (SO2)
  • Sulfur impurities in fossil fuels, like coal and crude oil, can react with oxygen when the fuels are burned to produce sulfur dioxide gas. This gas can dissolve in rain water to produce acid rain which damages structures, and wildlife habitats such as lakes and forests.
• nitrogen oxides (NOx)

  • When fuels are burned in engines, oxygen and nitrogen from the air can react together at high temperatures to produce oxides of nitrogen. These can also dissolve in rain water to produce acid rain.
  • Nitrogen dioxide is a red-brown toxic gas, and can cause respiratory diseases like bronchitis. Catalytic converters in cars convert most of the NO gases back to harmless nitrogen.
• Fuel

  Releases energy when combusted (burned)
• Fuels

  • Coal
  • Hydrocarbons (e.g. petrol, diesel)
• Fuels

  • Contain the elements carbon and hydrogen
• Combustion of fuels

  1. Carbon and hydrogen atoms react with oxygen in the air (oxidized)

  2. Forms carbon dioxide and water vapor (complete combustion)

  3. Forms carbon monoxide (incomplete combustion)
• Carbon dioxide is a greenhouse gas
• Carbon monoxide is a toxic gas
• Carbon monoxide detectors are used in homes
• Sulfur dioxide

  Produced when fuels containing sulfur are burned
• Oxides of nitrogen (NOx)


  Produced at high temperatures when nitrogen and oxygen in air react
• Sulfur dioxide and NOx can cause breathing problems and acid rain
• Particulates

  Black carbon particles and unburned hydrocarbons produced from burning fuels
• Particulates can damage human health and reduce sunlight reaching the Earth's surface (global dimming)