Coal and Petroleum
Natural Resources: Resources, which are obtained from nature,
are called natural resources. Some natural resources can be used
directly, while using some others we need the help of some
technology .for example given in below fig
Inexhaustible Natural Resources:Resources which do not exhaust
and which are available in plenty in nature are known as
inexhaustible natural resources. For example air, sunlight, etc .
Exhaustible Natural Resources:Resources which get exhausted and are
not available in nature in plenty and are known as exhaustible
natural resources. They take longer to get replenished. For example
coal, petroleum, forest, minerals, etc.Coal and Petroleum:Coal and
petroleum are exhaustible natural resources as their availability
is limited in nature. Coal and petroleum are used mainly as fuel.
Coal is used as fuel, petroleum products are used to run vehicle
and for many other purposes. Coal and petroleum are known as fossil
fuels since they are formed from remains of living
organism.CoalCoal is a black coloured stone-like material. Coal is
used to produce electricity in thermal power stations. Coal was
used to run steam engine till recent years in India. Coal gives
carbon dioxide when burnt in air.C + O2------------>
CO2Formation of Coal
About 300 millions year ago, dense forest in low lying lands of
earth got buried because of many natural processes. In the due
course, they sank deeper and deeper. Inside the earth, because of
high pressure and temperature they slowly converted into coal. Such
slow process of conversion of dead vegetation into coal is called
carbonization.Coal is considered as fossil fuel as it is formed
because of carbonization of dead remains of living organism. Coal
is mined from earth and processed to obtain many useful products,
such as coal,coke, coal tar, etc
Coke Coke is almost pure form of carbon. Coke is a porous, black
and similar to coal. Coke has high percentage of carbon and very
low percent of impurities. It is obtained from destructive
distillation of a particular type of coal. Coke is used as fuel, as
reducing agent in the smelting of iron ore in blast furnace. It is
used in the manufacturing of steel and in the extraction of many
types of metals.Coal TarCoal tar is obtained as one of the
by-products while obtaining the coke or coal gas. Coal tar is a
highly viscous liquid and brown-black in colour. It is a variable
mixture of many substances.Coal tar is used in the manufacturing of
many products; such as synthetic dyes, drugs, explosive, perfumes,
plastics, roofing material, etc. as starting material.Till about
two decades ago, coal tar was used as binding material in the
making of roads. Now-a-days bitumen is used in making of roads in
the place of coal tar.
Coal gasCoal gas is also one of the by-products in the
processing of coke. Coal gas is used as fuel mainly for heating in
many industries.Followings the different types of Coal: 1. Lignite
(Brown Coal) contains 25 35 % carbon. 2. Bituminous coal (Soft
coal) contains 45 86 % carbon. 3. Anthracite coal (Hard coal It has
the highest heat energy) contain 87 97%carbon.
PetroleumThe word petroleum is used for both naturally occurring
crude oil and other petroleum products, which are obtained after
refining of crude oil, such as petrol, diesel, etc. Petrol and
diesel are highly consumed fuel today as these are used to run
vehicles.Petroleum is a dark oily liquid having unpleasant
odor.Formation of Petroleum
Petroleum is formed from the dead remains of living organisms
which lived in sea and were buried millions of year ago below the
sea bed. Because of high pressure and temperature those dead
remains were transformed into petroleum. Since, petroleum is the
product of dead remains, so it is known as fossil fuel.Extraction
of petroleumPetroleum is extracted from the reservoir usually found
in sea beds and river basin by drilling through pipe lines. Such
places where reservoir of petroleum are found and extracted out by
drilling are known as oil well.
Oil drilling machineRefining of PetroleumAfter extraction,
petroleum is refined to obtain petrol, diesel, lubricating oil,
wax, paraffin, bitumen, kerosene, etc. Place where refining process
of petroleum is done is called petroleum refinery.
Some of the petroleum products and their uses
Petroleum productsUses
PetrolFuel in motor car, aviation, solvent for dry cleaning
DieselFuel for heavy vehicle, such as trucks, rail engine, small
vehicle, such as jeep car, for jet air crafts, small generators,
etc.
Liquid Petroleum GasFuel in households, and in vehicles.
KeroseneFuel for stoves, jet aircrafts, lamps, etc.
Lubricating oilUsed as lubricants mainly in engines.
Paraffin waxUsed in manufacturing of ointment, candles,
cosmetics, etc.
BitumenUsed in making of paints, road, etc.
Natural GasNatural gas is naturally occurring hydrocarbon gas.
Natural gas is a mixture of methane, higher alkanes, carbon
dioxide, etc. Natural gas is found in deep underground rock
formation as fossil fuel. It is one of the most important
fuel.Natural gas can be transported through pipeline and can be
compressed to smaller volume. Compressed natural gas (CNG) is used
for running vehicle. Natural gas can be used directly for burning
as fuel. It is a clean fuel as it creates least pollution.Natural
gas is used as starting material in many industries, such as
fertilizer and chemical.In India natural gas reserves are found in
Tripura, Rajasthan, Maharashtra, and Krishna and Godavari delta.
The advantages of CNG and LPG fuels are : they have high calorific
value They can be transported easily through pipelines. They are
clean fuels and do not give smoke when burnt. they burn without
producing any smoke
Harmful effects of burning fossil fuels: How it affect the
environment? The increases in carbon dioxide lead to large scale
environmental damage such as acid rain. Carbon dioxide that the
remains in the upper atmosphere will tend to trap sun rays, which
is called the "greenhouse effect" and leads to global warming.
People can become sick from breathing carbon monoxide emitted from
vehicles. Burning of coal releases sulfur and nitrogen, which help
form acid rain.
Some Natural Resources are LimitedPetroleum, coal, natural gas,
etc. are natural resources but available in limited amount. Thus,
it is necessary to use them with care.
Some steps to conserve fossil fuels (Natural Resources): Switch
off the engine of vehicle when waiting on signals or at other
places. Drive the vehicle with constant and moderate speed.
Maintain the correct tyre pressure for low consumption of fuel.
Maintain the vehicle by regular checking to ensure less consumption
of fuel
Exercise1. What are the advantages of using CNG and LPG as
fuels?Ans:
2. Explain why fossil fuels are exhaustible natural
resources.Ans.
3.Describe characteristics and uses of coke.Ans.
Class : 8 (CBSE)Sub: ScienceSelf Learning Material
By Avani PanchalBed: 2014/015Id No: 14162057
