What is Coal? - Types, Properties, Uses, and Environmental Impacts

Coal is a combustible black or brownish-black sedimentary rock composed mostly of carbonized plant matter, used as a fuel. Coal is the remains of ancient plants that have been buried for millions of years underground. It is a fossil fuel, meaning it was formed from the remains of living organisms that have been buried and subjected to high temperatures and pressures over time.
Coal is primarily composed of carbon, with smaller amounts of other elements such as hydrogen, oxygen, and nitrogen. There are four main types of coal, each with different properties and uses:
1. Anthracite: This is the highest rank of coal, with a high carbon content (92-98%) and a low volatility. It is hard, black, and has a high heating value. Anthracite is used primarily for industrial purposes, such as generating electricity.
2. Bituminous: This type of coal has a medium carbon content (45-86%) and is soft, black, and has a high heating value. Bituminous coal is the most common type of coal used for electricity generation.
3. Sub-bituminous: This type of coal has a low carbon content (35-45%) and is soft, brownish-black in color. Sub-bituminous coal is used primarily for generating electricity.
4. Lignite: This is the lowest rank of coal, with a low carbon content (25-35%) and a high moisture content. Lignite is soft, brown, and has a low heating value. It is primarily used for generating electricity.
Coal is an important fuel source for generating electricity, and it is also used in the production of steel and cement. However, coal mining can have significant environmental impacts, including air and water pollution, and the release of greenhouse gases that contribute to climate change. As a result, many countries are transitioning away from coal and towards cleaner forms of energy, such as wind and solar power.