Q1. WHAT DO YOU KNOW ABOUT COAL? EXPLAIN
GIVE THE BASIC KNOWLEDGE ABOUT COAL.
HIGHLIGHT THE HISTORY, USE AND TYPES OF COAL.
Coal is the solid and black fuel which is found in the in the form of Sedimentary Rocks. Burning coal produces energy therefore; it is used specially in steel making. Some other valuable chemical substances are also achieved from coals which are used in drugs, Insecticides, artificial fiber and oil making. The trees, greenery and jungles which were buried under the ground million year ago, they are converted into stone which is called coal. Coal, petrol, natural gas etc. are different forms of fuel and all these fuels are called ‘Fossil Fuels’ because the living creatures which were buried under the ground million years back, with the passage of time through enormous weight, chemical reactions and heat, are converted into different forms of fuels. Hydro-carbon; the mixture of hydrogen and carbon, embodies in coal. The layers of the soil, during million years, deposited on the forest buried under the ground. These jungles adopted the shape of black stone. Since trees contain hydrogen, carbon, oxygen, nitrogen, sulfur etc., the components of the coal are also the same. The quality of coal depends on the carbon contained by it. The higher is the proportion of hydrogen, better would the quality of coal.
Ancient man used to utilize wood, dried grass and straws and animal dung as fuel. The reference of coal, historically, is found in the writings of Greek philosopher and scientist Aristotle who referred the ‘coal like rock which was discovered in Thrace. Although no authentic reference is available about coal but according to historians, coal was obtained from Fu-Shan period 1000 B.C and Chinese used it for smelting metal for coinage. According to a historic record, coal was used in Rome before 4 centuries for obtaining energy. Iron smiths used coal in 13th. century for smelting metals for manufacturing different goods. There is a written prove that in 13th. century, coal was being used as the source of energy and domestic fuel in Britain,Scotland and continent of Europe. In the beginning of 18th. century, the demand for coal increased fast when the founders of iron John Wilkinson and Abraham Darby, used coal in the form of Coke for obtaining iron. As the metallic and engineering industry developed, the demand for coal continued to increase. When James Watt, by burning coal, created steam for running railway engine in 1769, the demand for coal reached at its height. The rapid development in Railway and steel industry increased the demand for coal miraculously.
The First World War was fought between 1914 to 1918 and during this period the use for petrol increased for obtaining energy, the demand for coal began to fall. Petrol in the war ships and diesel, electric and natural gas in railway engines replaced coal.
In 1970 when the world prices of petrol increased fast for replacing petrol by coal in the Thermal Electric Plants, the demand for coal increased again. Two third of total electricity produced in the world is obtained from the Thermal stations generated on the basis of coal. One forth quantity of coal mined, is used in iron and steel industry.
TYPES OF COAL:
Coal, in fact, is the rocky form of carbon therefore; the classification of type of coal is based on the amount of carbon in the coal. There are four types of coal given as under:
Peat is the most inferior type of coal. It contains lesser quantity of rotten plants and higher proportion of water and other impurities. This is the reason that it contains hardly 30 per cent of carbon therefore; it creates more smoke and less heat (energy).
2. LIGNITE COAL:
Lignite coal is also known as ‘Brown Coal’ due to its brown colour. Since this type of coal is formed at the second stage of coat making process, it contains lesser quantity of carbon (45 to 65 per cent) while the proportion of moisture is more. Nevertheless, it contains more carbon than Peat type coal. It shrinks by wind and is less important for industrial Purposes.
3. BITUMINOUS COAL:
This type of coal is solid and is mostly used. it contains higher proportion of carbon; 60 to 80 per cent. It contains less proportion of water. Bituminous Coal, in comparison to Lignite Coal, contains less oxygen and more gas. This type is most suitable for making steam gas and coke. This is the reason that both production and consumption of this type of coal is higher. Four fifth of the total coal produced at global basis, consists on Bituminous Coal.
4. ANTHRACITE COAL:
It is best and highest quality of coal having 92 to 95 per cent carbon, less hydrogen and oxygen. This is the reason that it does not produce smoke in burning. Anthracite Coal percentage of the total coal produced in the world is 5 per cent only. The reserves of Anthracite coal are found in China and United States of America.
There are multiple uses of coal including Thermal electricity plants, steel industry, liquid gas industry, chemical raw materials, domestic fuel and steam.