Coal
Coal
Coal: Coal is black or brownish black in color. It is one of the oldest fuels. It is mainly made up of carbon along with other elements mainly hydrogen, sulphur, oxygen.
Carbonisation : The process of coal formation is known as carbonisation. The dead plants and vegetation due to temperature and high pressure over hundreds of years slowly turned into coal. This slow conversion of dead plants and forests into coal is called the process of carbonisation.
Formation of coal: Trees and other plants grown in swampy areas around 300 to 400 years ago died and remains got buried. In low oxygen conditions, high temperatures and absence of air, they formed a dark brown material called peat. Peat was compressed between layers of sediments and formed lignite. Even further compression resulted in formation of Anthracite. Depending on its carbon content it can be divided into three main types:
1. Anthracite: It has carbon content 92-98% and mainly used for heating. It is hard, black and glossy and is the source of any other fuel.
2. Bituminous coal: It has carbon content 60-80% and mainly used in heat and power generation and manufacturing of coke.
3. Lignite: It has carbon content around 25-35% and has lowest grade of coal. Commonly called brown coal. It is highly volatile and used in power generations.
Coal is processed further to obtain useful materials by destructive distillation(heating of coal at high temperature in absence of air in controlled environment).
On order of quality coal the four main varieties of coal can be graded from superior to inferior as ____________ | |||
| Right Option : C | |||
| View Explanation | |||
Which of the following is not a constituent of coal gas? | |||
| Right Option : A | |||
| View Explanation | |||
Bituminous coal is softer than anthracite. | |||
| Right Option : A | |||
| View Explanation | |||
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