COAL AND PETROLEUM

IMPORTANT TERMS

Calorific Value              It is defined as the amount of heat produced in kilojoules when one gram of fuel is completely burned.

Fossil Fuel                   Fossil fuels are formed from the buried remains of plants and animals over a period of millions of years. Examples - Coal, Petroleum etc.

Refining                      It is the process of separating a mixture into its useful constituents.

Fuel                            Fuel is a substance that gives heat and light energy on burning.

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NATURAL RESOURCES

All the resources which are obtained from nature are known as natural resources. Natural resources can be classified into two categories.

1. Inexhaustible Natural Resources
2. Exhaustible Natural Resources

Inexhaustible Natural Resources- These resources are present in unlimited quantity in nature and are not likely to be exhausted by human activity. Examples are: Sunlight, Air etc.

Exhaustible Natural Resources- These resources are present in nature in limited amount and can be exhausted by human activity. Examples: Forests, Wildlife, Minerals etc.

COAL

Coal is a black or brownish black in colour. It is as hard as stone. Coal is one of the fuels used to cook food. Earlier, it was used in railway engines to produce steam to run the engine. It is also used in thermal power plants to generate electricity.

Due to flooding, About 300 million years ago, the forests got buried under the soil. As more and more soil gets deposits over them, they were compressed under high temperature and pressure; dead plants got converted into coal. As coal mainly contains carbon, so this process is known as carbonization. Since it was formed from the remains of vegetation, coal is also called fossil fuel. We obtain different useful products from coal such as coke, coal gas, coal tar.

 

1. Coal Tar- It is a black, thick liquid with an unpleasant smell. It is a mixture of about 200 substances. Naphthalene balls used to repel moths are made by coal tar. Anti-dandruff shampoos, perfumes, ointments are made by coal tar.
2. Coke - It is a tough, porous and black substance which is almost a pure form of carbon. It is produced by heating bituminous coal to a very high temperature in the absence of air. Coke is used in manufacture of steel and in the extraction of many metals.
3. Coal Gas- It is a gaseous fuel obtained in the process of manufacturing coke. Earlier, it was used as domestic fuel and lighting fuel.

 

Coal gas was used for street light for the first time in London in 1810 and in New York around 1820.

 

PETROLEUM

Petroleum is a crude oil and is a complex mixture of solid, liquid and gaseous hydrocarbons. Petroleum is formed from organisms living in the sea. When these organisms die, their bodies settles at the bottom of the sea and gets covered with the layers of sand and clay. Over millions of years, absence of air, high temperature and high pressure transformed the dead organisms into petroleum and natural gas.

The world’s first oil well was drilled in Pennsylvania, USA, in 1859. Eight years later, in 1867, oil was struck at Assam. Later it was found in Gujarat, Mumbai High and in the river basins of Godavari and Krishna.

 

Refining of Petroleum

Petroleum is a dark oily liquid that has an unpleasant odour. It is a mixture of various constituents such as petrol, petroleum gas, diesel, lubricating oil, paraffin wax. The process of separating the various constituents of petroleum is known as refining of petroleum.

 

 

Sr. no.	Constituents of petroleum	Uses
	Petroleum Gas in liquid form	Fuel for home and industry
2.	Petrol	Motor fuel, solvent for dry cleaning, aviation fuel
3.	Kerosene	Fuels for stores, lamps and for jet crafts.
4.	Diesel	Fuel for heavy motor vehicles, electric generators.
5.	Lubricating Oil	Lubrication for different parts of engine
6.	Paraffin Wax	Ointments, candles, Vaseline etc.
7.	Bitumen	Paints and Roads surfacing

NATURAL GAS

Natural gas is a very important fossil fuel because it is easy to transport through pipes. Natural gas is stored under high pressure as Compressed Natural Gas (CNG). CNG is used as a fuel for transport vehicles because it is less polluting. It is a cleaner fuel. CNG is also used for power generation. Great advantage of CNG is that it can be directly used for burning in homes and factories where it can be supplied through pipes. Such a network of pipelines exists in Vadodara (Gujarat).

 

Uses of Natural Gas

• It is used for generation of electricity.
• It is used to produce ammonia.
• It is used to produce hydrogen
• It is used in manufacture of steel, glass, plastics and other products.

 

LIMITATION OF FOSSIL FUELS

The two main limitations of fossil fuels are the limited availability in nature and the air pollution caused due to their use.

Their use is also linked to global warming. It is therefore necessary that we use these fuels only in absolute need. This will results in better environment, smaller risk of global warming and their availability for longer period.

The limited availability is due to the slow process wherein it requires the dead organisms millions of years to convert into fuels. On the other hand, the known reserves of these will last only a few hundred years.

In India, the Petroleum Conservation Research Association (PCRA) advises people on how to save petrol/ diesel while driving. Some tips are:

1. Drive at a constant and moderate speed.
2. Switch off the engine at traffic lights or at a place where you have to wait.
3. Ensure correct tyre pressure.
4. Ensure regular maintenance of the vehicles.

 

INTERESTING FACTS

• Fossil fuels are producing 90% of the world’s energy.

• Coal’s share in the total world electricity production is about 40%.
• It takes almost 26 tons of raw petroleum to produce 1 litre of gas.
• It would take 422 years to produce that much fossil fuel that we use in one year.
• It takes around 800 pounds of coal to power a light bulb 24/7 for an entire year.
• Coal ash, a by-product of coal combustion, is used as filler for tennis rackets, golf balls etc.