Discover what coal is and how it is formed

Coal is a fossil fuel formed from plant remains that accumulated in swampy areas millions of years ago. Over time, these remains were buried under layers of sediment and subjected to high pressures and temperatures, causing their chemical and physical transformation. There are several types of coal, classified according to their carbon content and calorific value:

1. Peat: The least evolved, with low carbon content.
2. Lignite: More compact than peat, but still with low calorific value.
3. Hard coal: Medium-quality coal, used in industry.
4. Anthracite: The hardest and with the highest carbon content, very efficient as a fuel

Coal can be transformed in several ways, depending on its intended use:

• Natural carbonization. This is the geological process it mentioned earlier, where plant matter is converted into coal over millions of years.
• Industrial transformation. In industry, coal can undergo processes such as:
  • Cokeification. Coal is heated in the absence of air to produce coke, a carbon-rich material used in steelmaking.
  • Gasification. Coal is converted into synthesis gas (a mixture of hydrogen and carbon monoxide) that can be used as fuel or as a chemical feedstock.
  • Liquefaction. Coal is transformed into combustible liquids as a substitute for petroleum.

Source: The Sydney Morning Herald and The Age

Source: Mr Cognito