In this chapter you will get short revision notes for class 8th JKBOSE NCERT Science Chapter 2 Coal and Petroleum
Resource is anything that is useful and fulfill our basic needs.Resouces can be broadly classified as Natural resources and Man-made resources.
Inexhaustible Natural Resources
Natural resources which are present in nature in unlimited quantity and are not likely to get exhausted by human activities.Examples are sunlight, air.
Exhaustible Natural Resources
The amount of these resurces is limited in nature and they get exhausted by human use. For instance forests, wild life minerals etc are exhaustible natural resources.
Its a stone like black coloured fossil fuel used for cooking. Earlier it was used in steam engines of railways. It is also used in thermal power plants to produce thermal electricity.
Formation of Coal
Millions of years ago low laying areas on earth were covered by dense forests. These forests got buried due to natural processes such as earthquakes and floods. Due to high compression the temperature and pressure under soil increased. Slowly these dead plants converted to coal.
This slow process of conversion of dead vegetation into coal is carbonisation.
Coal is processed in industry to get some beneficial products such as coke, coal tar and coal gas.
Coke is a tough, porous and black substance and is almost pure form of carbon.It is used in manufacture of steel and in the extraction of many metals.
It is thick and black semi solid with an unpleasant smell. It is mixture of many substances. Products derived from coal tar are used in industries like synthetic dyes, drugs, explosives, plastics, paints, photography etc.
When coal is processed to get coke, coal gas is produced as a biproduct. Its used as a fuel in industries near the coal processing plants.
Petroleum is a natural resource from which many useful fuels such as petrol and diesel and many other substances are obtained.
Formation of Petroleum
Petroleum was formed from organisms living in the sea. After death the dead bodies of animals settled at the bottom of sea and got covered by sand and clay. These dead bodies were transformed into petroleum over millions of years due to absence of oxygen and under high pressure and temperature.
In India first oil well was drilled at Makum in Assam in 1867.
In India oil is found in Assam, Gujrat, Mumbai and the river basins pf Godavari and Krishna.
Refining of Petroleum and Its Constituents
Petroleum is a mixture of many substances. These substances are separated by refining in petroleum refinery. The constituents of petroleum with their uses are given in the table below.
|Constituents of Petroleum
|Liquified Petroleum Gas (LPG)
|Fuel for home and industry
|Fuel for motor and aviation
|Fuel for stoves, lamps and jet aircrafts
|Fuel for heavy motor vehicles
|Oinments, candles and Vaseline
|Paints, road surfacing
It is an important and clean fossil fuel. It is very easy to transport through pipes. Natural gas is stored under high pressure as Compressed Natural Gas (CNG). CNG is used for power generation.
It can be supplied directly to homes and industries through pipelines. Such a network of CNG pipleline supplies CNG in Vadodara (Gujrat) and some parts of Delhi.