CHAPTER-5 COAL AND PETROLIUM
Resource:- Those things which are useful for us are called resource.
Ex- Coal, petroleum, air, water, soil, wood, School, Railway, Road etc
Types of Resources
Natural resources
Human made (Artificial) resources
Natural resources: Those resources which are obtained from nature are called natural resources.
* Some of the natural resources can be used directly ex- water, coal etc
* While for using some others we need the help of some technologies.
Ex- Air, sun light, Petroleum
Type of Natural resources:-
Inexhaustible Natural Resources:- Those natural resources which are available in huge quantity and cannot be finished by human activities are called inexhaustible natural resources.
Ex- air, water, sunlight, soil, etc.
Exhaustible Natural Resources:- Those natural resources which are available in limited quantity and can be finished by human activitiesare called exhaustible natural resources.
Ex- coal, petroleum, forest, natural gas, mineraletc.
Fuels:– Those substance which burns in air to produce energy without releasing harmful gases in large quantities is called fuels.
Type of Fuels:-
Natural (primary)fuels
Derived (secondary)fuels.
* If a fuels is present in natural state,it is called natural fuels. It may be solid(wood),liquid(crude) and gas(natural gas).
* If a fuels is processed to improve its quality,it is called derived fuels. It may be solid(coke),liquid(kerosene) and gas(coal gas)
Characteristics of an ideal fuel
* It should have a high calorific value.
* It should not cause any pollution.
* It should be of low cost and easily available.
* It should be easy to handle, store and ransport.
* It should have moderate ignition temperature.
* It should have moderate rate of combustion.
Fossil:- Those dead remains of living organisms which are more than 10,000 years old are called fossils.
Fossil Fuels:- Exhaustible natural resources like Coal, petroleum, etc are formed from dead remains of plants and animals. These kind of resources are called fossil fuels.
Note- In this chapter we will discuss the exhaustible natural resources like Coal, petroleum, natural gases.
1.Coal:– Those fossil fuel which is hard as stone, black in colour and is mainly composed of carbon, hydrogen, and oxygen are called coal
Formation of Coal:
* There were dense forests in low lying areas on earth about 300 million years ago.
* Those forests got buried under the soil due to natural processes such as earthquakes.
* More layers of soil were deposited on them and compressed them.
* The high pressure and temperature over this buried forest converted them into coal.
Carbonisation: The process of conversion of vegetation into coal is called carbonization. The buried plants underwent carbonization and changed into coal.
Types Of Coal
Lignite Sub-bituminous Bituminous Anthracite Lignite Coal:-
* It is a brown-black in colour with high moisture and ash content.(soft coal)
* It has minimum carbon content raging from 25-35%.
* It produce very little amount of heat.
Sub-bituminousCoal:-
* It is a dull-black in colour.
* It has carbon content raging from 36-45%.
* It produces little higher heat than lignite when it burns.
BituminousCoal:-
* It is a dark brown, black in colour.it is common household coal.
* It has carbon content raging from 46-85%.
* It produces higher heat than lignite & Sun-bituminous coal when it burns.
AnthraciteCoal:-
* It is a black in colour.it is hardest coal, mainly used for industrial purpose.
* It has highest carbon content raging from 86-96%.
* It produce a great amount of heat when it burn.
Uses of Coal
Coal burns in air to produce heat and carbon dioxide. Coal is used as fuel because it provides high amount of heat.
C + O2 → CO2
* Coal was used as fuel in steam engines.
* Most of the thermal power plants still use coal as fuel.
* Coal is still being used as kitchen fuel in some households, dhabas and restaurants.
* Many useful products like coke, coal tar and coal gas are made by processing coal.
Destructive distillation of coal:- The process of heating coal in the absence of air is called Destructive distillation of coal. The main produces obtained by the destructive distillation of coal are as coke,coal tar and coal gas.
(a) Coke:
* Coke is purest form of carbon. It is tough, porous and black in color.
Applications: Coke is used in manufacture of steel and extraction of many metals.
(b) Coal Tar:
* It is a thick black colored liquid with an unpleasant smell.
* It is a mixture of about 200 substances.
Applications: The by-products obtained from coal tar are used in manufacturing of synthetic dyes, drugs, explosives, perfumes, plastics, paints, photographic materials, roofing materials, naphthalene balls(used to repel moths and other insects) etc.
* It is used for making the surface of roads. Bitumen (a petroleum product) has almost replaced coal tar for making road surface.
(c) Coal Gas:
* It is produced during processing of coke from coal.
* Cole gas is mixture of hydrogen, methane and carbon monoxide.
* Coal gas was used for street lighting for the first time in London in 1810 and in New York around in 1820.Now a days, it is used as a source of heat rather than light.
* Coal gas is used as fuel in many industries which are situated near coal mines because it is combustible.
2. Petroleum:- Those dark and viscous liquid with unpleasant smell which comes from oil wells are called Petroleum.
* It is commonly called as crude oil. also called the black gold.
* It name is derived from from Latin words Petra means Rock and Oleum means oil. Thus petroleum means rock oil.
* The main component of crude oil is hydrocarbon, Which contains a lot of energy.
Formation of Petroleum
* Organisms which lived in the seas and ocean millions of years ago got dead, their bodies buried under sand and clay.
* After millions of years, the absence of air, temperature and pressure converted them into petroleum and natural gas.
Refining of Petroleum
Crude oil(petroleum) is dark and viscous liquid with unpleasant smell. It contains many constituents like petroleum gas, petrol, diesel, lubricating oil, paraffin wax, etc.
Process of Refining of petroleum:- Petroleum is not very useful rather it needs to be refined to obtain useful products. Petroleum; from oil wells; is sent to oil refineries for processing.
Refining:- It is the process of separating the various constituents of petroleum and is carried out in a petroleum refinery.
Different constituents of petroleum and their uses:-
|
Constituent of petroleum |
Uses |
|
Liquefied Petroleum Gas (LPG) |
Fuel for home and industry. |
|
Petrol |
Fuel for motor vehicles, aviation fuel, solvent for dry cleaning. |
|
Kerosene |
Fuel for stoves, lamps and jet aircrafts. |
|
Diesel |
Fuel for heavy motor vehicles, generator and rail engine |
|
Lubricating oil |
Lubrication |
|
Paraffin wax |
Ointment, candle, Vaseline, etc. |
|
Bitumen |
Paint, road surfacing |
Petrochemicals:- The process of refining petroleum and natural gas obtain many useful compounds which are known as petrochemicals.
Ex: LPG, Kerosene, Petrol, Diesel etc.
Uses of Petrochemicals:
* LPG is used as fuel for domestic &industrial use.
* Kerosene is used as fuel for stove, lamps & jet planes.
* Petrol is more volatile than diesel both are used in automobiles.
* Lubricating oil is used to reduce friction in automobile parts and other rotating components inside a machine.
* Paraffin wax is used to make candles, ointments, Vaseline and cosmetics.
* Bitumen or asphalt is used to make paints & road surfacing.
3. Natural Gas: Natural gas is gas that is found along with petroleum in oil wells.
* In our country natural gas has been found in Tripura, Rajasthan, Maharashtra and in the Krishna Godavari delta.
Compressed Natural gas (CNG):- The natural gas which is stored under high pressure is called Compressed Natural Gas (CNG).
Advantage:- It causes less pollution. Moreover, it can be used directly at homes and factories for burning and other purposes as it can be easily be transported through pipes.
Application:-
* It is used as fuel in automobiles.
* It is used as a starting material for manufacturing of many chemicals and fertilizers.
* Currently, there is a huge network of pipelines in Vadodara and some in some areas of Delhi used for supplying CNG.
Limitations of Fossil Fuels:
* Fossil fuels like coal, petroleum etc. needs millions of years to get transformed from dead bodies to fuels. But, currently their demands are so high that after few hundred years there will be scarcity of these resources.
* Burning of fossil fuels adds carbon dioxide to the atmosphere. Thus, fossil fuel causes environmental pollution.
* Excess level of carbon dioxide in the atmosphere creates global warming.
Some preventive measures to save fuels by Petroleum Conservation Research Association (PCRA) :-
* Drive vehicles at constant and average speed as far as possible,
* Switch off the engine at traffic lights or at a place where you have to wait,
* Make sure pressure in tyres is correct.
* Always keep vehicles under good condition.