Coal and Petroleum PDF

COAL AND PETROLEUM W e use various materials for our Can air, water and soil be exhausted basic needs. Some of them are by human activities? You have already found in nature and some studied about water in Class VII. Is water h...

COAL AND PETROLEUM W e use various materials for our Can air, water and soil be exhausted basic needs. Some of them are by human activities? You have already found in nature and some studied about water in Class VII. Is water have been made by human efforts. a limitless resource? In the light of the availability of Activity 3.1 various resources in nature, natural resources can be broadly classified Make a list of various materials used into two kinds: by us in daily life and classify them as natural and man-made. (i) Inexhaustible Natural Resources: These resources are present in unlimited Natural Man-made quantity in nature and are not likely to be exhausted by human activities. Examples are: sunlight, air. (ii) Exhaustible Natural Resources: The amount of these resources in nature is limited. They can be exhausted by human activities. Examples of these resources are forests, wildlife, minerals, coal, petroleum, natural gas etc. Activity 3.2 (It is a group activity) Does this list include air, water, soil and minerals? Since all these are Take some containers. Fill them obtained from nature, they are called with popcorn/peanuts/roasted natural resources. gram/toffees. Divide students into groups of seven each. Further divide each group into three subgroups containing 1, 2 and 4 students. Can we use all our Label them as first, second natural resources and third generation respectively. forever ? 2024-25  These sub-groups represent the 3.1 Coal consumers. As population is You may have seen coal or heard about growing, second and third it (Fig. 3.1). It is as hard as stone and is generations have larger number of black in colour. consumers. Put one full container for each group on a table. Ask consumers of the first generation from each group to consume eatables from the container of their group. Now, ask the second generation consumers from each group to do the same. Ask students to observe carefully the Fig. 3.1: Coal availability of eatables in each Coal is one of the fuels used to cook container. If some thing is left in the food. Earlier, it was used in railway containers, ask third generation engines to produce steam to run the from each group to consume it. Now, engine. It is also used in thermal power finally observe whether all the plants to produce electricity. Coal is also consumers of the third generation used as a fuel in various industries. got the eatables or not. Also observe if anything is still left in any of the Story of Coal containers. Assume that the eatables in the Where do we get coal from and how container represent the total is it formed? availability of an exhausible natural resource like coal, petroleum or About 300 million years ago the natural gas. Each group may have a earth had dense forests in low lying different consumption pattern. Are wetland areas. Due to natural processes, the earlier generations of any group like flooding, these forests got buried too greedy? It may be that the earlier under the soil. As more soil deposited generations in some groups were over them, they were compressed. The concerned about the coming temperature also rose as they sank generation(s) and left something for deeper and deeper. Under high pressure them. and high temperature, dead plants got In this chapter we will learn about slowly converted to coal. As coal some exhaustible natural resources contains mainly carbon, the slow like coal, petroleum and natural gas. process of conversion of dead vegetation These were formed from the dead into coal is called carbonisation. Since remains of living organisms (fossils). it was formed from the remains of So, these are all known as fossil vegetation, coal is also called a fossil fuel. fuels. A coal mine is shown in Fig. 3.2. COAL AND PETROLEUM 33 2024-25  Fig. 3.2: A coal mine When heated in air, coal burns and about 200 substances. Products produces mainly carbon dioxide gas. obtained from coal tar are used as Coal is processed in industry to get starting materials for manufacturing some useful products such as coke, coal various substances used in everyday tar and coal gas. life and in industry, like synthetic dyes, drugs, explosives, per fumes, Coke plastics, paints, photographic materials, It is a tough, porous and black roofing materials, etc. Interestingly, substance. It is an almost pure form of naphthalene balls used to repel moths carbon. Coke is used in the manufacture and other insects are also obtained from of steel and in the extraction of many coal tar. metals. These days, bitumen, a petroleum Coal Tar product, is used in place of coal-tar for metalling the roads. It is a black, thick liquid (Fig. 3.3) with an unpleasant smell. It is a mixture of Coal Gas Coal gas is obtained during the processing of coal to get coke. It is used 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 Fig. 3.3: Coal tar rather than light. 34 SCIENCE 2024-25 as a fuel in many industries situated transformed the dead organisms into near the coal processing plants. petroleum and natural gas. Look at Fig. 3.4. It shows the deposits 3.2 Petroleum of petroleum and natural gas. You see You know that petrol is used as a fuel in that the layer containing petroleum oil light automobiles such as motor cycles/ and gas is above that of water. Why is it scooters and cars. Heavy motor vehicles so? Recall that oil and gas are lighter like trucks and tractors run on diesel. than water and do not mix with it. Petrol and diesel are obtained from a natural resource called petroleum. The The world’s first oil well was drilled word petroleum is derived from petra in Pennsylvania, USA, in 1859. Eight (rock) and oleum (oil) as it is mined years later, in 1867, oil was struck from between the rocks under Earth as at Makum in Assam. In India, oil is found in Assam, Gujarat, Mumbai shown in Fig. 3.4. High and in the river basins of Do you know how petroleum is Godavari and Krishna. formed? Petroleum was formed from Refining of Petroleum organisms living in the sea. As these organisms died, their bodies settled at Petroleum is a dark oily liquid. It has the bottom of the sea and got covered an unpleasant odour. It is a mixture of with layers of sand and clay. Over various constituents such as petroleum millions of years, absence of air, high gas, petrol, diesel, lubricating oil, temperature and high pressure paraffin wax, etc. The process of Wells Impervious Gas rock Oil Reservoir rock Water Fig. 3.4 : Petroleum and natural gas deposits COAL AND PETROLEUM 35 2024-25  Various constituents of petroleum and their uses are given in Table 3.1. 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’. 3.3 Natural Gas Fig. 3.5: A petroleum refinery Natural gas is a very important fossil fuel because it is easy to transport separating the various constituents/ through pipes. Natural gas is stored fractions of petroleum is known as under high pressure as compressed refining. It is carried out in a petroleum natural gas (CNG). CNG is used for refinery (Fig. 3.5). power generation. It is now being used Table 3.1 Various Constituents of Petroleum and their Uses S.No. Constituents of Petroleum Uses 1. Petroleum Gas in Liquid form Fuel for home and industry (LPG) 2. Petrol Motor fuel, aviation fuel, solvent for dry cleaning 3. Kerosene Fuel for stoves, lamps and for jet aircrafts 4. Diesel Fuel for heavy motor vehicles, electric generators 5. Lubricating oil Lubrication 6. Paraffin wax Ointments, candles, vaseline etc. 7. Bitumen Paints, road surfacing 36 SCIENCE 2024-25 as a fuel for transport vehicles because 3.4 Some Natural Resources it is less polluting. It is a cleaner fuel. are Limited The great advantage of CNG is that it can be used directly for burning in You have studied in the beginning of homes and factories where it can be the chapter that some natural resources supplied through pipes. Such a network are exhaustible like fossil fuels, forests, of pipelines exists in Vadodara (Gujarat), minerals etc. some parts of Delhi and other places. You know that coal and petroleum Natural gas is also used as a starting are fossil fuels. It required the dead organisms millions of years to get material for the manufacture of a number converted into these fuels. On the of chemicals and fertilisers. India has vast other hand, the known reserves of reserves of natural gas. In our country, these will last only a few hundred natural gas has been found in Tripura, years. Moreover, burning of these Rajasthan, Maharashtra and in the fuels is a major cause of air pollution. Krishna Godavari delta. Their use is also linked to global warming. It is therefore necessary that we use these fuels only when absolutely necessary. This will result Can coal, petroleum in better environment, smaller risk of and natural gas be global warming and their availability prepared in the laboratory from dead for a longer period of time. organisms? In India, the Petroleum Conservation Research Association (PCRA) advises people how to save petrol/diesel while driving. Their tips are l drive at a constant and moderate speed as far as possible, No. Their formation is a very l switch off the engine at traffic lights slow process and or at a place where you have to wait, conditions for l ensure correct tyre pressure. their formation cannot be created l ensure regular maintenance of the in the laboratory. vehicle. COAL AND PETROLEUM 37 2024-25 KEYWORDS WHAT YOU HAVE LEARNT COAL Ü Coal, petroleum and natural gas are fossil COAL GAS fuels. Ü Fossil fuels were formed from the dead remains COAL TAR of living organisms millions of years ago. COKE Ü Fossil fuels are exhaustible resources. Ü Coke, coal tar and coal gas are the products FOSSIL FUEL of coal. NATURAL GAS Ü Petroleum gas, petrol, diesel, kerosene, paraffin wax, lubricating oil are obtained by PETROLEUM refining petroleum. PETROLEUM Ü Coal and petroleum resources are limited. We REFINERY should use them judiciously. Exercises 1. What are the advantages of using CNG and LPG as fuels? 2. Name the petroleum product used for surfacing of roads. 3. Describe how coal is formed from dead vegetation. What is this process called? 4. Fill in the blanks. (a) Fossil fuels are , and. (b) Process of separation of different constituents from petroleum is called. (c) Least polluting fuel for vehicle is. 5. Tick True/False against the following statements. (a) Fossil fuels can be made in the laboratory. (T/F) (b) CNG is more polluting fuel than petrol. (T/F) (c) Coke is almost pure form of carbon. (T/F) (d) Coal tar is a mixture of various substances. (T/F) (e) Kerosene is not a fossil fuel. (T/F) 6. Explain why fossil fuels are exhaustible natural resources. 38 SCIENCE 2024-25  7. Describe characteristics and uses of coke. EXERCISES 8. Explain the process of formation of petroleum. 9. The following Table shows the total power shortage in India from 1991–1997. Show the data in the form of a graph. Plot shortage percentage for the years on the Y-axis and the year on the X-axis. S. No. Year Shortage (%) 1 1991 7.9 2 1992 7.8 3 1993 8.3 4 1994 7.4 5 1995 7.1 6 1996 9.2 7 1997 11.5 Extended Learning — Activities and Projects 1. Get an outline map of India. Mark the places in the map where coal, petroleum and natural gas are found. Show the places where petroleum refineries are situated. 2. Choose any five families of your neighbourhood. Enquire whether their energy consumption (coal, gas, electricity, petrol, kerosene) has increased or decreased in the last five years. Enquire also about the measures they adopt to conserve energy. 3. Find out the location of major thermal power plants in India. What could be the reasons for their being located at those places? For more information, visit: l www.energyarchive.ca.gov l web.ccsd.k12.wy.us l web.pcra.org COAL AND PETROLEUM 39 2024-25