COAL AND PETROLEUM W - NCERT

1 COAL AND PETROLEUMCOAL AND PETROLEUMCan air, water and soil be exhaustedby human activities? You have alreadystudied about water in Class VII. Is watera limitless resource?In the light of the availability ofvarious resources in nature, naturalresources can be broadly classifiedinto two kinds:(i) Inexhaustible Natural Resources:These resources are present in unlimitedquantity in nature and are not likely tobe exhausted by human are: sunlight, air.(ii) Exhaustible Natural Resources: Theamount of these resources in nature islimited. They can be exhausted byhuman activities. Examples of theseresources are forests, wildlife, minerals,coal, PETROLEUM , natural gas (It is a group activity)Take some containers. Fill themwith popcorn/peanuts/roastedgram/toffees. Divide students intogroups of seven each. Further divideeach group into three subgroupscontaining 1, 2 and 4 them as first, secondand third generation use various materials for ourbasic needs.

2 Some of them arefound in nature and somehave been made by human a list of various materials usedby us in daily life and classify themas natural and we use all ournatural resourcesforever ?Does this list include air, water, soiland minerals? Since all these areobtained from nature, they are callednatural 22 These sub-groups represent theconsumers. As population isgrowing, second and thirdgenerations have larger number one full container for eachgroup on a table. Ask consumers ofthe first generation from each groupto consume eatables from thecontainer of their group. Now, askthe second generation consumersfrom each group to do the same. Askstudents to observe carefully theavailability of eatables in eachcontainer. If some thing is left in thecontainers, ask third generationfrom each group to consume it.

3 Now,finally observe whether all theconsumers of the third generationgot the eatables or not. Also observeif anything is still left in any of that the eatables in thecontainer represent the totalavailability of an exhausible naturalresource like coal, PETROLEUM ornatural gas. Each group may have adifferent consumption pattern. Arethe earlier generations of any grouptoo greedy? It may be that the earliergenerations in some groups wereconcerned about the cominggeneration(s) and left something this chapter we will learn aboutsome exhaustible natural resourceslike coal, PETROLEUM and natural were formed from the deadremains of living organisms (fossils).So, these are all known as CoalYou may have seen coal or heard aboutit (Fig. ). It is as hard as stone and isblack in : CoalCoal is one of the fuels used to cookfood.

4 Earlier, it was used in railwayengines to produce steam to run theengine. It is also used in thermal powerplants to produce electricity. Coal is alsoused as a fuel in various of CoalWhere do we getcoal from and howis it formed?About 300 million years ago theearth had dense forests in low lyingwetland areas. Due to natural processes,like flooding, these forests got buriedunder the soil. As more soil depositedover them, they were compressed. Thetemperature also rose as they sankdeeper and deeper. Under high pressureand high temperature, dead plants gotslowly converted to coal. As coalcontains mainly carbon, the slowprocess of conversion of dead vegetationinto coal is called carbonisation. Sinceit was formed from the remains ofvegetation, coal is also called a fossil coal mine is shown in Fig.

5 AND PETROLEUM572021 22 SCIENCE58 Fig. : A coal mineCoal GasCoal gas is obtained during theprocessing of coal to get coke. It is usedCoal gas was used for street lightingfor the first time in London in 1810and in New York around 1820. Now adays, it is used as a source of heatrather than days, bitumen, a petroleumproduct, is used in place of coal-tarfor metalling the : Coal tarWhen heated in air, coal burns andproduces mainly carbon dioxide is processed in industry to getsome useful products such as coke, coaltar and coal is a tough, porous and blacksubstance. It is an almost pure form ofcarbon. Coke is used in the manufactureof steel and in the extraction of TarIt is a black, thick liquid (Fig. ) withan unpleasant smell. It is a mixture ofabout 200 substances. Productsobtained from coal tar are used asstarting materials for manufacturingvarious substances used in everydaylife and in industry, like syntheticdyes, drugs, explosives, perfumes,plastics, paints, photographic materials,roofing materials, etc.

6 Interestingly,naphthalene balls used to repel mothsand other insects are also obtained fromcoal 22 COAL AND PETROLEUM59as a fuel in many industries situatednear the coal processing PetroleumYou know that petrol is used as a fuel inlight automobiles such as motor cycles/scooters and cars. Heavy motor vehicleslike trucks and tractors run on and diesel are obtained from anatural resource called PETROLEUM . Theword PETROLEUM is derived from petra(rock) and oleum (oil) as it is minedfrom between the rocks under Earth asshown in Fig. you know how PETROLEUM isformed? PETROLEUM was formed fromorganisms living in the sea. As theseorganisms died, their bodies settled atthe bottom of the sea and got coveredwith layers of sand and clay. Overmillions of years, absence of air, hightemperature and high pressureRefining of PetroleumPetroleum is a dark oily liquid.

7 It hasan unpleasant odour. It is a mixture ofvarious constituents such as petroleumgas, petrol, diesel, lubricating oil,paraffin wax, etc. The process ofFig. : PETROLEUM and natural gas depositsThe world s first oil well was drilledin Pennsylvania, USA, in 1859. Eightyears later, in 1867, oil was struckat Makum in Assam. In India, oil isfound in Assam, Gujarat, MumbaiHigh and in the river basins ofGodavari and the dead organisms intopetroleum and natural at Fig. It shows the depositsof PETROLEUM and natural gas. You seethat the layer containing PETROLEUM oiland gas is above that of water. Why is itso? Recall that oil and gas are lighterthan water and do not mix with rockImperviousrock2021 22 SCIENCE60separating the various constituents/fractions of PETROLEUM is known asrefining.

8 It is carried out in a petroleumrefinery (Fig. ).Various constituents of petroleumand their uses are given in Table useful substances are obtainedfrom PETROLEUM and natural are termed as Petrochemicals .These are used in the manufactureof detergents, fibres (polyester, nylon,acrylic etc.), polythene and otherman-made plastics. Hydrogen gasobtained from natural gas, is used inthe production of fertilisers (urea).Due to its great commercialimportance, PETROLEUM is also called black gold . Natural GasNatural gas is a very important fossilfuel because it is easy to transportthrough pipes. Natural gas is storedunder high pressure as compressednatural gas (CNG). CNG is used forpower generation . It is now being usedTable Various Constituents of PETROLEUM and their of PETROLEUM Gas in Liquid formFuel for home and industry(LPG) fuel, aviation fuel, solvent fordry for stoves, lamps and for jet for heavy motor vehicles, waxOintments, candles, vaseline , road surfacingFig.

9 : A PETROLEUM refinery2021 22 COAL AND PETROLEUM61as a fuel for transport vehicles becauseit is less polluting. It is a cleaner great advantage of CNG is thatit can be used directly for burning inhomes and factories where it can besupplied through pipes. Such a networkof pipelines exists in Vadodara (Gujarat),some parts of Delhi and other gas is also used as a startingmaterial for the manufacture of a numberof chemicals and fertilisers. India has vastreserves of natural gas. In our country,natural gas has been found in Tripura,Rajasthan, Maharashtra and in theKrishna Godavari Natural Resourcesare LimitedYou have studied in the beginning ofthe chapter that some natural resourcesare exhaustible like fossil fuels, forests,minerals know that coal and petroleumare fossil fuels. It required the deadorganisms millions of years to getconverted into these fuels.

10 On theother hand, the known reserves ofthese will last only a few hundredyears. Moreover, burning of thesefuels is a major cause of air use is also linked to globalwarming. It is therefore necessary thatwe use these fuels only whenabsolutely necessary. This will resultin better environment, smaller risk ofglobal warming and their availabilityfor a longer period of India, the PETROLEUM ConservationResearch Association (PCRA) advisespeople how to save petrol/diesel whiledriving. Their tips areldrive at a constant and moderatespeed as far as possible,lswitch off the engine at traffic lightsor at a place where you have to wait,lensure correct tyre regular maintenance of coal, petroleumand natural gas beprepared in thelaboratory from deadorganisms?No. Theirformation is a veryslow process andconditions fortheir formationcannot be createdin the 22 SCIENCE62 KEYWORDS KEYWORDS KEYWORDS KEYWORDS KEYWORDSCOALCOAL GASCOAL TARCOKEFOSSIL FUELNATURAL GASPETROLEUMPETROLEUMREFINERY WHA WHA WHA WHA WHAT YT YT YT YT YOU HAOU HAOU HAOU HAOU HAVE LEARNTVE LEARNTVE LEARNTVE LEARNTVE LEARNT Coal, PETROLEUM and natural gas are fossilfuels.