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How is coal found ? Its Stages and Disadvantages


COAL : 

Coal is a solid fossil fuel formed in several stages as buried remains of land plants that lived 300-400 million year ago. were subjected to intense heat and pressure over millions of years.

Various stages of Coal : 

The various stages of coal during the coalification of wood is 

Wood -----> Peat --------> Lignite ------> Bituminous coal--------> Anthracite.


The carbon content of Anthracite is 90% and its calorific value is 8700 K.cal. The carbon content of bituminous, lignite and peat are 80,70, and 60% respectively.

India has about 5% of world's coal, Indian coal is not good because of poor heat capacity. 

Disadvantages of  using Coal 

1.When coal is burnt it produces Co2, causes global warming.

2.Since coal contains impurities like S and N, it produces toxic gases during burning.


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