Chapter 5: Coal and Petroleum (Notes)
Posted on : 19-11-2017 Posted by : Admin


All human beings need basic things for survival. Take few examples. Our day starts with the sun light, mom needs to cook breakfast and lunch for school, and again to go to school we need to take the transport, there again we might take road transport or the rail transport. When we are at school we need the lights and fans in the classrooms for the comfort and so on.

In the above example we require sun, the fuel required to run the transport, the road ways should be good enough to travel, and we should have electricity or generator to run the lights and fans in the class rooms. In this example we are making use of sunlight, petrol or diesel for transport and electricity.

Natural resources are the materials which occur in nature. They can be exploited for economic gain. Examples of natural resources include sunlight, petrol, diesel etc. Sunlight comes from sun, but from where does the petrol and Diesel come from, let us discuss. There are two types of natural resources:

Inexhaustible Natural Resources: These are the resources which are never ending, how much you use, they will never end.

Example: Sunlight, Air.

Exhaustible Natural Resources: These resources are limited. As you consume them the quantity is decreased.

Example: Forests, coal, petroleum, natural gas, etc…


About 300 million years ago, due to natural calamities, like earthquakes, floods the forests are buried under the soil and later layers of soil was formed above the dead plants and trees.

The dead plants were compressed as they went deeper and deeper under the soil, which generated temperature and pressure in them and those were converted into Coal. The slow process of conversion of dead vegetation into coal is called Carbonization. Coal is black in color. Coal produces the gas Carbon dioxide while heating.

Uses of coal

  1. Used in railway engines to produce steam
  2. Used in thermal plants to produce electricity
  3. Used as fuel in many industries nowadays.

Coal products

Coal while being processed produces various products mentioned below:

  • Coke: It is a hard and black in color. Used in the manufacture of steel and also to extract few metals from it.
  • Coal tar: It is a thick liquid, which is black in color and which as very unpleasant smell. This is made up of 200 different substances. The products formed from coal tar are synthetic dyes, drugs, explosives, perfumes, plastics, paints, photographic materials, roofing materials, etc…Naphthalene balls which are used to repel insects are also produced from Coal tar. Now a days Bitumen (a petroleum product) is used in place of coal tar for metalling of roads.
  • Coal Gas: Coal Gas is formed when the Coal was under the process of making the Coke. This    gas is used in street lights in the olden days, however now is used as fuel in industries. Coal gas was used for street lighting for the first time in London in 1810 and in New York around 1820. Now a days, it is used as a source of heat rather than light.


Petroleum is formed by the dead organisms in the sea. Millions of years ago, the dead bodies of the sea organisms settled down deep under the sea with no light and air. This resulted in the production of petroleum and natural gas under heavy pressure and temperature conditions.

The world’s first oil well was drilled in Pennsylvania, USA, in 1859. Eight years later, in 1867, oil was stuck at Makum in Assam. In India, oil is found in Assam, Gujarat, Mumbai High and in the river basins of Godavari and Krishna. Resources which are formed millions of years ago from the dead remains of living organisms are called Fossils. Coal, Petroleum and Natural Gas are called Fossil fuels.

Petroleum is a dark oily liquid. It is a mixture of various substances, like petroleum gas, petrol, diesel, lubricating oil, paraffin wax, etc. The process of separating these constituents from petroleum is called refining. Refining is carried out in petroleum refinery. Many useful substances are obtained from petroleum and natural gas. These are termed as ‘Petrochemicals’. These are used in the manufacture of detergents, fibres (polyester, nylon, acrylic etc.), polythene and other man-made plastics. Hydrogen gas obtained from natural gas, is used in the production of fertilisers (urea). Due to its great commercial importance, petroleum is also called ‘black gold’.

The following are various Constituents of Petroleum and their Uses:

Petroleum Constituent Uses
Petroleum Gas in Liquid form (LPG) Fuel for home and industry

Motor fuel, aviation fuel, solvent for dry cleaning

Kerosene Stoves, lamps and for jet aircrafts

Heavy motor vehicles, electric generators

Lubricating oil Lubrication
Paraffin wax Ointments, candles, Vaseline etc.
Bitumen Paints, road surfacing


This is a very important fossil fuel. It is in the compressed form usually called as CNG (Compressed natural gas).  Natural gas is used for power generation. It is also used as the fuel for vehicle as it is less polluting. It is also used for the manufacturing of chemicals and fertilizers.

Natural gas is transported through the pipelines. A network of natural gas pipelines exists in Vadodara in Gujarat. In India we find natural gas in Tripura, Rajasthan, Maharashtra, Krishna and Godavari districts.

These resources petroleum, Natural gas and Coal are formed after millions of years decomposing, and now it will take another millions of years to form the same. So these resources are exhaustible, so it is our responsibility to use them as less as possible.

Try to walk if the destination is near, take public transport like trains, buses. Usage of these resources in limit will also save our earth from pollution, which will decrease the risk of Global warming. Regular pollution checks as to be done to the vehicles.

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