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 & pressure over millions of years.
Various stages of coal:
1.wood
2.peat
3.lignite
4.bituminous coal
5. Anthracite
The carbon content of anthracite is 90 percentage & its calorific vslue is 8700 k.cal.the carbon of bituminous coal,lignite& because are70,70,&60 percentsge respectively.
India has about 5 percentage of worlds coal.Indian coal is not good because of poor heat capacity.
Disadvantages of using coal:
- When coal is burnt it produces CO2,causes global warming.
2.Since coal contains impurities like S&N,it produces toxic gases during burning.
