Use of Hydrogen as fuel in fuel cell and its challenges:

Use of Hydrogen as fuel in fuel cell and its challenges:

Hydrogen is the simplest and lightest element. Storage is one of the greatest problems for hydrogen. It leaks very easily from container meant for storage, no mater how strong and no matter how well insulated. Therefore, hydrogen in storage tanks always evaporates, at a rate of at least 1.7 percent per day.

Another important property of hydrogen is it is very reactive in nature. When hydrogen gas comes into contact with metal surfaces it decomposes into hydrogen atoms, which are so very small that they can penetrate metal. This causes structural changes that make the metal brittle.

One of the largest problems perhaps hydrogen fuel cell transportation has is its fuel tank size. In gaseous form of hydrogen, a volume of 238,000 litres gas is necessary to replace the same energy capacity of 20 gallons of petrol (gasoline). One option is to compress the gas. Because of gas’s low density property, compressed gas does not give a car as useful a as of gasoline as far as storage volume is concerned. Moreover, a compressed hydrogen fuel tank would be at risk of developing pressure leaks either through accidents or through normal wear and such leaks could result in dangerous explosions.

In case, the hydrogen is liquefied, the liquid hydrogen would give a density of 0.07 grams per cubic centimeter. In that case, it may require almost the four times volume of gasoline for a given amount of energy release. Besides, there are many difficulties in storing liquid hydrogen. Liquid hydrogen is cold enough to freeze air. Accidents may occur from pressure build-ups resulting from plugged valves. Besides, energy costs of liquefying the gas and refrigerating it also to be considered while calculating economy.

Other option may be considered is the use of powdered metals to store the hydrogen in the form of metal hydrides. The volume of stored metal hydrides would be little more than that of the metals themselves; but storing in this form, hydrogen would be far less reactive. However, the weight of the metals will make the storage tank very heavy.

As far as production of hydrogen is concerned, hydrogen does not freely occur in nature in useful quantities. Therefore hydrogen must be split from molecules, either molecules of methane derived from fossil fuels or from water. Currently, most hydrogen is produced by the treatment of methane with steam (the equation is CH4 (g) + H2O + e > 3H2(g) + CO(g)). The CO(g) in this equation is carbon monoxide gas, which is a byproduct of the reaction. Again the production of CO, which converts into CO2 is a greenhouse gas – not environment friendly option. Again, at present we do not have viable technology to obtain hydrogen from water, other than electrolysis – which is not energy saving option.

Therefore, as of now, it is a challenge before us to use hydrogen economically, efficiently and environment-friendly way. As lot research activities are going on in this field, very soon positive favorable result could be seen.

Principle of Hydrogen fuel cell:

The hydrogen fuel cell is an electrochemical energy conversion device. Hydrogen and oxygen are fed into opposite sides of a cell, which are separated by a membrane permeable to hydrogen ions but not electrons. Hydrogen gas molecules entering the anode side of the cell are ionized in the presence of a catalyst to form protons and electrons. The protons pass through the membrane to combine with the oxygen and electrons to produce water at the cathode. The electrons flow through an external circuit from the anode to the cathode, creating an electrical current, which powers an electric load such as a motor.

Alternative Fuels:

Alternative Fuels:

Alternative fuels are derived from resources other than petroleum. Some are produced domestically, reducing our dependence on imported oil, and some are derived from renewable sources. Often, they produce less pollution than gasoline or diesel. Some of the important alternative fuels are:

(1) Ethanol is produced domestically from corn and other crops and produces less greenhouse gas emissions than conventional fuels.

(2) Bio-diesel is derived from vegetable oils and animal fats. It usually produces less air pollutants than petroleum-based diesel.

(3) Natural gas is a fossil fuel that generates less air pollutants and greenhouse gases.

(4) Propane, also called liquefied petroleum gas (LPG), is a domestically abundant fossil fuel that generates less harmful air pollutants and greenhouse gases.

(5) Hydrogen can be produced domestically from fossil fuels (such as coal), nuclear power, or renewable resources, such as hydropower. Fuel cell vehicles powered by pure hydrogen emit no harmful air pollutants.

Coal washeries for beneficiation of high-ash coal:

Coal washeries for beneficiation of high-ash coal:

Coal seam in some of the countries has drift origin, resulted in intimate mixing of mineral matter with coal, giving rise to more ash content. Coal washeries are to reduce ash content in coal. For coking coal and non-coking / energy coal quality improvement, coal washeries are used. Coal having drift origin, coal-ash distribution in the coal matrix is so interwoven that coal is essentially required to crush to smaller sizes for better liberation of coal and ash particles.

Coal washing is a process of separation mainly based on difference in specific gravity of coal and associated impurities like shale, sand and stones etc so that we get relatively pure marketable coal without changing the physical properties of the coal. Coal beneficiation largely depends on gravity difference of coal and ash particles after passing through sizing. In general, technologies adopted for coal washeries are: (a) Jigs; (b) Heavy Media Baths; (c) Heavy Media Cyclones; (d) Froth Floatation; (e) Water-only Cyclones.

The major equipments used in a coal washery are: (a) De-shaling jig; (b) washing jig; (c) heavy media bath for coarse coal; (d) heavy media cyclone for smaller size coal; (e) froth floatation for treating fines below 0.5mm; (f) water-only-cyclone / hydrocyclone; (g) cyclone washer. Magnetite having specific gravity in the range of 4.8 to 5.4 is used in washery for washing process which is ground to –200 mesh and mixed in water to maintain the desired gravity in heavy media bath or hydrocyclone for separation of coal with its impurities. The froth flotation plant uses light diesel oil and pine oil, as conditioning and frothing agents. The other main supporting equipments used in Washeries are : Rotary Breaker; Feeder Breaker; Gyratory Crusher, Single/double roll Crushers, Impact crushers, Hammer mill ,Ball Mill etc.; Tipplers; Vibro/Reciprocating feeders; Vibrating Screens; Various kinds of pumps; Vacuum pumps; Compressors; Blowers; Conveyor Beltings and gear boxes; Bucket elevator, scrapper conveyor, flight conveyors etc.; Magnetic Separator; Thickeners; Filters; Gravity Controllers; Automatic Ash Analysers.

The following advantages for using washed coal in thermal power stations:

1. Reduction in emissions of particulate matter

2. Owing to reduced ash content in coal, reduction in size of coal handling plant at power station end; reduction in size of ash disposal unit; smaller ash ponds

3. Reduction in ash will result in less wear and tear of ball mills, induced draught and forced draught fans; less leakage of boiler tubes and less consumption of fuel oil for flame stabilization

4. Owing to 2 and 3 above, the capital cost of the power station will come down for the same design capacity

5. Railways will carry thermal coal with less ash resulting in increased freight carrying capacity for the railways

6. Reduction in freight charges to the power station

7. Better control in thermal power station operations and the control settings would not need to be changed frequently to take care of fluctuations in the heat value in coal feed

8. Increased plant availability and resultant higher Plant Load Factor (PLF)

Continuous research and development efforts, including trial and adoption of latest equipment/ technology are required, in order to get improvement upon existing system of coal washery. Moreover, the environmental issues are also to be looked upon.

Heat value of coal:

Heat value of coal:

The heat value of or the energy value is the amount of energy that can be converted into the actual heating ability of the coal sample. The heat value is very important factor for any fuel, goes for conversion of energy or actual usefulness. By heat value the quality of coal or any fuel measured.

The basic parameters of coal sample analysis are moisture, volatile matter, ash, and fixed carbon. Moisture, ash, or volatile matter do not participate and creation of energy when coal is burnt; so the heat value is more depending on the fixed carbon a sample has. To be precise, heat value or heat of combustion is the energy released as heat when a compound undergoes complete combustion with oxygen. The chemical reaction is typically a hydrocarbon reacting with oxygen to form carbon dioxide (CO2), water (H2O) and since the reaction is exothermic, heat is generated. The quantity of heat generated is expressed as calorific value (Q), which is the heat liberated by its complete combustion with oxygen. It is expressed in terms of kcal/kg or Btu/lb (in British unit).

Generally, formula applies for calculation of calorific value Q is

Q = 337C + 1442(H - O/8) + 93S

Where, Q is the calorific value.

C is the fixed carbon content in the sample.

H is the hydrogen content.

O is the oxygen content.

S is the sulfur content in the sample.

Therefore, the quality of coal, in other words, the heat value of coal can be improved by reduction of ash content in coal sample. Coal beneficiation or washing of coal can reduce ash in coal.

Properties of coal:

Properties of coal:

Physical and chemical properties of coal are very important factor to know before a particular coal sample is used. Coal as a fuel comes in various types or ranks, such as, (1) lignite or brown coal; (2) bituminous coal or black coal; and (3) anthracite. Several techniques have been developed for studying the physical and chemical properties of coal. The most commonly employed systems of classification are those based on analyses that can be performed relatively easily in the laboratory, e.g., determining the percentage of volatile matter lost upon heating to about 950 °C (about 1,750 °F), the amount of heat released during combustion of the coal under standard conditions etc. Each type of coal discussed above, has a certain set of physical parameters which are mostly controlled by moisture, volatile content and its carbon content.

(1) Moisture: It is an important property of coal. Moisture held within the coal itself is known as inherent moisture. Moisture in coal may be of (i) Surface moisture, i.e., water held on the surface of coal particles; (ii) Hydroscopic moisture, i.e., water held by capillary action within the micro-fissures of the coal; (iii) Decomposition moisture, i.e., water held within the coal's decomposed organic compounds; (iv) Mineral moisture, i.e., water which comprises part of the crystal structure of hydrous silicates such as clays. Total moisture is analyzed by loss of mass between an untreated sample and the sample once analyzed.

(2) Volatile matter: Volatile matter in coal is the presence of various components of coal (except for moisture), which are liberated at high temperature of about 950 °C (about 1,750 °F), in the absence of air. This is usually a mixture of short and long chain hydrocarbons, aromatic hydrocarbons and some sulphur. The volatile matter of coal is determined under rigidly controlled standards.

(3) Ash: Ash content of coal is the non-combustible residue left after coal is burnt. It is the bulk mineral residue left after carbon, oxygen, sulphur and water is driven off by combustion.

(4) Fixed carbon: The fixed carbon in a coal sample is the carbon found in the material which is left after volatile matters are driven off. This slightly differs from the ultimate carbon content of the coal because some carbon is lost in hydrocarbons with the volatiles. Fixed carbon in coal sample is a very useful parameter, as it is used as an estimate of the amount of coke that will be yielded from a sample of coal. Fixed carbon is determined by removing the moisture and the mass of volatile matters, above, from the original mass of the coal sample.

(5) Other physical and chemical criteria: Presence of oxygen, hydrogen, sulphur etc. is evaluated in a coal sample. Density, particle size distribution, abrasion etc., are some of the physical criteria of coal is also evaluated.

(6) Besides above physical or chemical tests and analysis made in order to determine the handling and pollutant profile of a coal, the energy output of a coal is the important factor, which also determined by using a bomb calorimeter. Energy output of a coal sample is the specific energy output of a coal during complete combustion. This is required particularly for coals used in boiler for in steam-raising in a coal-fired power plant.

(7) Spontaneous combustion of coal: Almost all types of coal ignite spontaneously in suitable environmental conditions. The spontaneous ignition of coal stockpiles is a serious economic and safety problem. Preventive measures may be adopted while coal stacking includes (i) periodic compaction, (ii) the use of a low angle slope, (iii) protection of the coal stockpiled with an artificial barrier and (iv) covering it with ‘ash–water’ slurry made with fly ash from the same power station.

Underground coal mining:

Underground coal mining:

When coal seams obtained at a great depth, surface coal mining is not feasible; the extraction of coal is done by a method called underground mining. Underground mining currently accounts for about 60% of world coal production.

In underground coal mining, there are two system of working – (1) board and pillar method; (2) Longwall method.

A. In board and pillar method, all along the coal seam, coal pillars are formed by developing drives. Drives are supported by timbers. The coal pillars thus formed kept standing till the development is done upto the mine boundary in a certain portion of the block called ’district’. Once, full area is developed in several districts, the pillars are to be extracted by a method called ‘depillaring’.

B. In Longwall (retreat) method of coal mining, drives are made at the two periphery of a district till end and these two drives are joined by another drive. This drive becomes the coal production face, where continuous machines like shearer loader, chain conveyors etc., are put. The hydraulic supports are made at the face. This is a high productive method for coal extraction from underground coal mines.

C. In underground coal mines, methane gas present in the originally formed coal seam gets released in to the mine atmosphere during excavation of coal. Methane when mixed with air in the proportions between 5 and 14 % forms an explosive mixture. Hence, there is possibility of a methane-air mixture being dangerously formed in the working areas. In underground coal mines, there is also an additional risk as ‘coal-dust’, when mixed with air, can undergo a dust explosion when suitably ignited. Both methane-air and coal dust explosions cause loss of life and extensive damage to the underground mines. Therefore, avoidance of such incidences is to be observed essentially by taking suitable safety measures. Keeping proper ventilation is again very important aspect in underground mines. Sufficient ventilation air dilutes the noxious gases generated in the coal seams and also due to blasting operation.

Surface or opencast coal mining:

Surface or opencast coal mining:

Coal has been used worldwide as a fuel for centuries. Around 1800 coal became the main energy source for the Industrial Revolution. The expanding railway system of various countries lead development of coal driven power steam trains. Britain developed the main techniques of underground coal mining. In fact, the first industrial revolution began in Britain in the 1700s, and later spread to almost every part of Europe, North America, and Japan, was based on the availability of coal to power steam engines. Since then coal has been very important fuel for us. Therefore, since its introduction, coal mining has played an intricate role in the economic stability.

Coal mining is the removing of coal from the earth by mining safely and economically. Coal is used for power generation, for making steel and for other industrial activities including domestic heating. When coal is used for fuel in power generation, it is referred to as steaming or thermal coal. Coal that is used to create coke for steel manufacturing is referred to as coking or metallurgical coal. The most economical method of coal extraction from coal seams depends on various factors such as, depth, thickness of coal strata, quality of the seams, geology of the coal bearing strata and environmental factors of the area being mined. Coal mining processes are generally differentiated by the method by which a particular seam is to be mined, i.e., whether they are to mined by the surface operation or by underground operation. Many coals extracted from both surface and underground mines require washing in a coal preparation plant for reduction of ash to increase its heat value.

Surface coal mining: When coal seams are near to the surface, it may be economical to extract the coal using surface mining method (also referred to as open cast or open pit). Lots of heavy earth moving machineries are employed in this method. The overburden, i.e., waste material overlaid coal seam, is excavated before excavation of coal. A list of major opencast mining machineries employed for coal and ore mining are given below. These are used for high production in mines:

(a) Dragline - Dragline excavation systems are heavy equipment used in civil engineering and surface mining. A dragline bucket system consists of a large bucket which is suspended from a boom (a large truss-like structure) with wire ropes. The bucket is maneuvered by means of a number of ropes and chains.

(b) Shovels - Shovels are heavy equipment used in civil engineering and surface mining. These are hydraulically operated. For mining purpose the capacity employed is very large.

(c) Dumpers - A dumper is a vehicle designed for carrying bulk material or blasted coal or minerals. In mining, dumpers are loaded by a Shovel. After loading dumper is moved to the unloading site where the blasted coal or minerals are unloaded with the help of hydraulic jack.

(d) Drilling machines – Drill machines are for drilling holes for blasting purposes.

(e) Loaders - A loader, also called a front loader, front end loader, bucket loader, is a type of tractor, usually wheeled, that uses a wide square tilting bucket on the end of movable arms to lift and move material. Loaders are used mainly for uploading materials into trucks / dumpers.

(f) Air Compressors – Compressors are used in mining with drilling machines. Small dia. Jack hammer holes are drilled with the help of air compressors.

Natural gas, a gaseous fuel, has considerable use:

Natural gas, a gaseous fuel, has considerable use:

Natural gas is an important fuel available in gaseous state. It is a fossil fuel consisting primarily of methane, found in oil fields either in dissolved form (associated with liquid petroleum or crude oil) or isolated in natural gas fields (non-associated with liquid petroleum or crude oil). Coal-bed methane available in coal seams can also be treated as natural gas.

Methane (CH4), a lightest and short chain hydrocarbon molecule, is the primary component in natural gas. In addition to CH4, some heavier gaseous hydrocarbons e.g., ethane (C2H6), propane (C3H8), butane (C4H10) etc., are also available. In some oil field other sulfur containing gases, in varying amounts are also found.

As far as heat value concerned, it varies greatly with the gas, however, on an average the gross heat of combustion of one normal cubic meter of commercial quality of natural gas is around 39 mega joules.

Natural gas processing is done to purify the raw natural gas extracted from underground gas fields. The processed natural gas, which is almost pure methane (dry gas), is piped for residential as well as for commercial and industrial use for manufacture of plastics, drugs and dyes. The heavy hydrocarbons such as butane, propane, and petrol are extracted as liquids.

The transportation and storage are the major difficulty faced for use of natural gas because of its low density. Transportation natural gas through gas pipelines are economical, but many a times become are impractical as it may have to cross oceans or because of political hassles between two countries. Liquefied natural gas (LNG) or compressed natural gas (CNG) can be transported across ocean or by tank trucks directly to the end users. Storing natural gas in underground caverns near ultimate end-users, now-a-days, is the best proposition; as it helps to meet gas’s volatile demands. The under ground storage system various advantages, such as it is much safer, prevents from accidental fire, protect environment and protect from terrorist attacks as well. For this purpose, depleted gas reservoirs from previous gas wells, salt domes, or specially built cavern may be used for keeping liquefied natural gas. Uses of natural gas:

• Because of availability, transportability and better storage-ability, natural gas has become a major source of electricity generation through the use of gas turbines and steam turbines. Particularly high efficiencies in power generation can be achieved through combining gas turbines with a steam turbine in combined cycle mode.

• Environmentally, natural gas is much cleaner than other fossil fuels such as oil, coal; as it produces less carbon dioxide (CO2) per unit energy released. For an equivalent amount of heat, burning natural gas produces about 30% less carbon dioxide than burning petroleum and about 45% less than burning coal. Combined cycle power generation using natural gas is thus the cleanest source of power available using fossil fuels. Because of its techno-economic advantages this technology is widely used wherever gas can be obtained at a reasonable cost.

• Natural gas is a major feedstock for the production of ammonia, for use in fertilizer production.

• Because of its environmentally cleaner in nature, compressed natural gas (CNG) is used as cleaner alternative to petrol (gasoline) or diesel driven road transport in many countries.

• Natural gas is supplied to homes for its use as cooking fuel.

• Because of relatively environment-friendly in nature, people are finding ways to use it for varied industrial and commercial purpose.

Countries such as, Russia, Iran, Qatar, Saudi Arabia, UAE, USA, Nigeria, Algeria, Venezuela, Iraq have greatest natural reserve in the world.

Petroleum / crude oil / natural gas (exploration, production, processing etc.):

Petroleum / crude oil / natural gas (exploration, production, processing etc.):

Petroleum or more commonly known as Crude oil, available naturally below surface of the earth; used by human being as fuel and applicable for production of various chemicals. Modern society heavily depends on Petroleum / crude oil inclusive of natural gas. Crude oil has become most significant fuel and raw material for production of chemicals in present day world. Because of higher demand for hydrocarbons, pressure on exploration, production and further processing of crude oil / natural gas is tremendous and due this the prices of crude oil have touched sky level recently.

The main activities of the petroleum industry are: (a) Exploration of crude oil and natural gas; (b) Production of crude and natural gas; (c) Processing consists of refining crude for gasoline, diesel, lubricants and further production other down stream chemicals by cracking; (d) Marketing and distribution of gasoline, diesel, lubricants and other processed chemicals.

A. Exploration: Petroleum / crude oil / natural gas are extracted mainly from oil wells found in various oil fields spread all over the world. Various methods are employed in exploration of crude and natural gas and to optimize the process techno-economically. Most exploration process depends on highly sophisticated technology to detect and determine the extent of these deposits. Exploration is initiated with gravity survey, magnetic survey to detect large scale features of the sub-surface geology of the area of investigation. More detailed seismic surveys are conducted at the areas of interest (known as leads). Seismic surveys are basically based on the principle of velocity / time taken by sound wave on reflection at various formations of ground strata, as velocity differs at various interfaces. Finally, when a prospect has been identified, evaluated and passes the selection criteria, exploration wells are drilled to know the presence of oil or gas.

B. Oil / gas Production: Next stage after exploration is production or recovery from the oil reservoir identified after exploration. (a) Primary recovery of oil and gas is done when underground pressure in the oil reservoir is sufficient. This pressure forces the oil to bring it to surface. (b) In Secondary oil recovery various techniques are employed, as this is done when pressure is low in the underground oil reservoir. Pumps such as, beam pumps, electrical submersible pumps are used to bring the oil to the surface. Water injection, gas lift (when CO2 or air is used) and natural gas re-injection are some of the methods also applied when required. (c) Tertiary oil recovery is mainly done to maintain recovery from very low pressure oil reservoir; by reduction of viscosity of underground oil by injecting heat, vapour, surfactants, solvents or miscible gases (CO2).

C. Processing of crude: Processing of crude is done in oil refineries; where more useful petroleum products such as gasoline, kerosene, diesel, LPG (liquefied petroleum gas) etc., are produced by a process known as fractional distillation. Products having lower boiling point leaves from top and higher boiling point products leave the fractioning column at the bottom. Therefore, light distillates are LPG, gasoline, naptha; middle distillates are kerosene, diesel and heavy distillates including residuum are fuel oil, lubricating oils, wax and tar.

D. Petroleum is the major source of organic chemicals. In petrochemical industry major chemicals are derived from two constituents of crude oil – Xylene and Naptha. These chemical raw materials are broken down into basic chemicals such as Butadiene. Basic chemicals are made into finished chemicals or chemical products either direct conversion or through an intermediate. For example, butadiene can be directly made into synthetic rubber or butadiene may be processed into an intermediate such as acetone and later acetone may be used for manufacturing other finished polymers.

• Raw material – Naphtha, Xylene.

• Basic chemicals – Butadiene, Ethylene, Propylene etc.

• Intermediates – Acetone, Phenol, Acrylonitrile, Vinyl acetate, Ethanol etc.

• Polymers – PVC, Polyester fiber, Polystyrene, Polyethylene etc.

E. Major Crude oil and natural gas producing countries are: (a) Saudi Arabia (an OPEC country); (b) Russia; (c) USA; (d) Iran (an OPEC country); (e) China; (f) Mexico; (g) Canada; (h) UAE (an OPEC country); (i) Venezuela (an OPEC country); (j) Norway; (k) Kuwait (an OPEC country); (l) Nigeria (an OPEC country); (m) Brazil; (n) Algeria (an OPEC country); (o) Iraq.

Energy from Nuclear Fuel:

Energy from Nuclear Fuel:

Nuclear energy is the energy that directly releases after controlled Atomic reactions. Nuclear power is obtained from release of nuclear energy, a type of nuclear technology involving the controlled use of nuclear reactions. Out of two (fission and fusion) known technology, fission technology is used by nuclear power plant and fusion technology is under development stage.

A. In nuclear fission technology is splitting of the nucleus of an atom to produce two more or less equal fragments. In this process, a large amount of energy is produced; which is used for generation of electricity. This phenomenon of fission reaction is mostly done with nuclei of the element uranium; when bombarded by neutrons, to produce a great variety of products including large amount of heat energy.

B. Nuclear power plants generate electricity by using heat obtained from such fission reaction; usually use uranium-235 (U-235) as fuel. The nucleus of U-235 has 92 protons and 143 neutrons. When bombarded by extra neutrons on U-235, it loses atomic balance and becomes unstable to split into smaller pieces of fission products and releases more neutrons. This post splitting mass difference causes to release huge energy in the form of heat. The extra neutrons produced responsible for further chain reaction within the leftover mass of uranium. In nuclear power plant this generated heat is utilized to drive a turbine generator to produce electricity. As no physical burning of fuel is taken place, the nuclear power plants emit very low carbon dioxide (CO2) as compared to their counterpart of coal, oil or gas fired power plants. World has quite a large reserve of Uranium (more than gold); mostly located in Australia (35 per cent), Russia and CIS countries (29 per cent), Canada (13 per cent), Africa (8 per cent), and South America (8 per cent).

C. Nuclear power poses great environmental advantages:

• Emission of carbon dioxide and other greenhouse gases into atmosphere is very negligible; thereby not responsible for global warming;
• Quantum of energy obtained is very large from very less quantity of nuclear fuel (the complete fission of 1 kg of U-235 could produce 8 x 1013 joules of energy, almost one million times more than the amount of energy produced by burning 1 kg of coal);
• Neutron produced from fission reaction used for initiating self-sustaining series of reactions; i.e., chain reaction, results in a continuous release of nuclear energy.

D. Nuclear Fusion technology is to combine two light atomic nuclei to form one heavier nucleus. This process generates tremendous amount of energy - heat. As this technology generates enormous amount of energy, we are now struggling to control this quantum of energy obtained out of fusion reaction– thereby, not yet developed fully. Developed world is making every effort to make nuclear fusion technology workable. The energy released from atomic fusion can be unimaginably great - our celestial Sun and other stars shine through this fusion since their inception. If fusion energy does become practicable it would offer the advantages such as:

(1) an effectively limitless source of fuel;

(2) it would be of inherent safety , as the amount of radioactive material present would be much low;

(3) as waste products that are less radioactive and simpler it would be easer to handle them than those from fission .

Formation of Fossil Fuels (Coal, Petroleum):

Formation of Fossil Fuels (Coal, Petroleum):

Energy and minerals are the life-blood of modern day world. Rapid industrial growth and growth in human population has brought the consumption of energy and mineral to a very high level. Ironically, resources are not unlimited. We know, the fossil fuels – coal, petroleum and natural gas – provide most of our needs of energy; till recently, coal used to be major source of energy. Due to recent hike in price of petroleum products, coal again is getting importance as major source of energy.

Geologically fossil fuels (coal and petroleum) have been originated from very old-buried (more than hundreds of million years old) of plants, animals and microorganisms and overlaid with sediments. This burial protected these vegetation and microorganism from oxygen, which would have completed its breakdown, and preserved it instead it into partially decayed form as coal and petroleum. Coal originated from plants & trees, whereas petroleum & natural gas originated from marine organism. Chemically, all fossil fuels consist largely of hydrocarbons, which are compounds composed of hydrogen and carbon.

The various stages of coal formation are:

(a) Peat - partially carbonized plant matter,

(b) Lignite - soft brownish-black coal with low carbon content,

(c) Sub-bituminous coal - soft coal with intermediate carbon content,

(d) Bituminous coal - soft coal with higher carbon and lower moisture content than sub-bituminous coal,

(e) Anthracite coal - hard coal with highest carbon content and lowest moisture content.

Methane (CH4) gas, which is a hydrocarbon compound, is also entrapped in most of the coal seams; is now finding importance in recovery from coal seam due to recent energy crisis.

The petroleum and gas deposits are particularly prevalent in coastal zones. Largely, our cars and vehicles are powered by diesel, gasoline and natural gas.

Vast quantity of oil is locked-up in a fine grained sedimentary rock called oil shale. This contains high proportion of ‘kerogen’, a solid organic material, when heated produces oil vapour from which oil can be recovered.

COAL AND OTHER FORM OF FUEL

COAL AND OTHER FORM OF FUEL:

We all know, energy is important in almost every aspect of modern life - societies need increasing amounts of energy as they grow and develop. Mostly energy we know are in the form of Electricity, Heat, Light, Sound, nuclear etc. Fuel is a material that is burnt or chemically altered to obtain energy. Fuel releases energy either through chemical means in the way of combustion or of nuclear means in the way of nuclear fission or fusion. The essence of any fuel is that energy is stored; and when needed it is released either by combustion or by nuclear reactions.

Coal is one of the most important fuels available as energy source – not only does coal provides electricity, but it is an essential ingredient for steel, cement and other industrial activities. Coal is one of fossil fuel (hydrocarbons) available on the earth crust. Another important fossil fuel (hydrocarbons) is Petroleum (liquid or natural gas form).

Nuclear fuel is kind of material from which we obtain Nuclear energy, by way of nuclear fission chain reaction or by nuclear fusion (a kind of energy produced by any celestial stars).

Therefore, fuel is most important element in our every day life, for growth, for sustaining civilization; as it help us generate energy.