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chemistry of fuels

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Presented by
• Ali Zia
• Bilal Ali
• Hafiz M Kashif

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CONTENTS
Introduction of fuels.
Chemical composition of fuels.
Nuclear fuels.
Fossil fuels.
Industrial processing of ...

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Introduction
• The word “Fuel” is came from Old French feuaile, from
feu fire, ultimately from Latin focus fireplace, hear...

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chemistry of fuels

  1. 1. Presented by • Ali Zia • Bilal Ali • Hafiz M Kashif
  2. 2. CONTENTS Introduction of fuels. Chemical composition of fuels. Nuclear fuels. Fossil fuels. Industrial processing of fuel. Energy from fuels.
  3. 3. Introduction • The word “Fuel” is came from Old French feuaile, from feu fire, ultimately from Latin focus fireplace, hearth. • A fuel is any compound that has stored energy. • This energy is captured in chemical bonds through processes such as photosynthesis and respiration.
  4. 4.  Energy is released during oxidation.  Most common form of oxidation is the direct reaction of a fuel with oxygen through combustion.  It is simply the reaction of substances with oxygen and converts chemical energy into heat and light.
  5. 5.  Wood, gasoline, coal, and other fuels have energy-rich chemical bonds created during using the energy from the sun.  This energy is released when the fuel is burned (i.e. the release of chemical energy). • Are useful reserve of energy and therefore used extensively to satisfy the demands of an energy-dependent civilization.
  6. 6. History • The first known use of fuel was the combustion of wood or sticks by Homo erectus nearly two million years ago. • Throughout most of human history fuels derived from plants or animal fat were only used by humans. • Charcoal, a wood derivative, has been used since at least 6,000 BCE for melting metals.
  7. 7. • Charcoal briquettes are now commonly used as a fuel for barbecue cooking. • Coal was first used as a fuel around 1000 BCE in China. • With the concept development of the steam engine, coal came into more common use as a power source. • Coal was later used to drive ships and locomotives. • In 20th and 21st centuries, the primary use of coal is to generate electricity.
  8. 8. Heat produced by fuels • Fuels are any materials that store potential energy in forms that can be practicably released and used for work or as heat energy. • The heat energy released by many fuels is harnessed into mechanical energy via an engine. • Or is valued for warmth, cooking, or industrial processes, as well as the illumination that comes with combustion.
  9. 9.  Fuels are also used in the cells of organisms in a process known as cellular respiration, where organic molecules are oxidized to release usable energy.  Fuels contain one or several of the combustible elements: carbon, hydrogen, Sulphur, etc.  During combustion C and H combine with O2 with liberation of heat. C+O2 CO2+ 94 Kcals 2H2+O2 2H2O +68.5 Kcal
  10. 10. Characteristics of a good Fuel 1. It should ignite easily. • Ignition temperature: The temperature of the fuel at which ignition starts and continues to burn without further addition of heat is called ignition temperature.  It should be moderate for a good fuel.
  11. 11. 2. It should give out a lot of heat, that is, its specific heat should be high. 3. Low smoke and combustible matter such as ash. 4. Inexpensive and readily available. 5. easy to store and transport. 6. low ash content.
  12. 12. Types of Fuel Classifications of Fuels Based on Physical State Based on occurrence  Solid fuel (e.g., wood, coal)  Liquid fuel (e.g., crude petroleum, natural gasoline) Gaseous fuel (e.g., natural gas)  Secondary or Synthetic fuels (e.g., Water Gas, charcoal, petroleum coke).  Primary or natural fuels (e.g., wood, coal)
  13. 13. Composition of fuel In terms of their chemical composition their principle constituents are carbon(C)and hydrogen (H). The other important constituents are nitrogen (N) Oxygen(O) and Sulphur (S). These elements combine to form organic compound in fossil fuels, in contrast to other earths constituents which are inorganic(such as sand and other rocks and minerals). Different types of fuels have different constitutional elements that give them some unique features. The elements present in the fuels determine their ignition and combustion properties.
  14. 14. • All coal contains various combustible materials, left from the alteration of the vegetal matter, moisture, and varying amounts of mineral matter which on burning appear as ash. • The usual means of determining the composition of a coal are: (1) by an ultimate analysis and (2) by a proximate analysis. Composition of coal
  15. 15. • The combined water is presented by the oxygen content of the coal plus the equivalent amount of hydrogen necessary to unite with it to form water. • Free or available hydrogen is the hydrogen remaining after combined hydrogen and on burning can produce heat by union with oxygen of the air. Moisture
  16. 16. Coal ash • The ash in coal is composed of two classes: (1) free ash and (2) fixed ash. • The ash-forming constituents of coal are: (a) impurities present as an intimate mixture in the coal substance, derived from the ash in the original vegetal matter or from sedimentation etc., during coal formation. (b) bits of clay, shale, "slate" pyrites etc. that occur in the form of veins and partings and (c) fragments from the roof and floor, etc. that are mixed with the coal in the process of mining.
  17. 17. • The "free ash" is mostly that formed by processes (b) and (c), and, consisting of dirt, slate, pyrites, etc., can be washed out of the coal by suitable coal-washing machinery. The amount of such ash in the coal varies considerably in different parts of the mine. • The "fixed ash," formed mostly by process (a), is disseminated throughout the coal fairly uniformly, and usually amounts to from 2 to 3 percent.
  18. 18. • The presence of sulfur in coal is always harmful, since it affects the quality of coke for metallurgical uses, increases the corrosion of boilers, and usually affects the fusibility of the ash. • It occurs in three forms: (1) pyritic sulfur, (2) organic sulfur, and (3) sulfate sulfur. Sulphur
  19. 19. • The nitrogen content of coals is of great economic importance, because of the value of the nitrogen obtained as ammonia in the manufacture of by-product coke. • The nitrogen, present as a constituent of the organic compounds which go to make up the coal substance, is mainly derived from the original vegetal matter (the N2 content of trees varying from 1 to 3 per cent), although a small proportion may originally have come from animal matter or from the air. Nitrogen
  20. 20. • Consists in determining the percentages of the "ultimate" constituents; namely, carbon, hydrogen, oxygen, sulfur, nitrogen, and ash in the dry coal. • The amounts of carbon, hydrogen, and nitrogen are determined by the ordinary methods of organic quantitative analysis. • The sulfur may be determined by analysis of washings from the bomb calorimeter used in determining the heating value of the coal. Ultimate analysis
  21. 21. Ultimate analysis • The amount of oxygen is always determined by difference, the sum of the percentages of carbon, hydrogen nitrogen and sulfur, plus the percentage of ash, being subtracted from 100 to give this constituent. • pyrites to be converted to ferric oxide in the ash, that the oxygen be determined by subtracting from 100 the sum of carbon, hydrogen, nitrogen, ash, and five-eighths the sulfur.
  22. 22. Proximate analysis The proximate analysis of coal, which includes the determination of moisture, volatile matter, fixed carbon, ash, and sulfur, is: • Much easier • Quicker than the ultimate analysis • And is the one more commonly made, since it furnishes most of the data necessary to determine the commercially important properties of the coal.
  23. 23. Proximate analysis • The amount of moisture is determined by the loss in weight of a small sample on heating for 1 to 1.5 hr. at 220°F (104°C) to 230°F(110°C). • The volatile matter is determined by heating a 1-gm sample of the coal as purchased in a closed crucible at 1740°F (950°C) for 7 min. The percentage of volatile matter is the percentage loss as thus determined minus the percent moisture. Proximate analysis
  24. 24. • Ash is determined on the dried sample from the moisture determination by completely burning off all combustible matter until the ignited material reaches a constant weight. • The percentage of fixed carbon is equal to 100 minus the sum of moisture, volatile matter, and ash. Proximate analysis
  25. 25. • Fuel produced by the natural resources like anaerobic decomposition of dead organisms. • It is a general term for buried combustable geological deposit of organic material, formed from decayed plants and animals buried under earth crust millions of year ago • Fossil fuels are hydrocarbons. • Its main components are Carbon and Hydrogen. • Sulphur ,Nitrogen ,Oxygen and other metals are also present in small amount. Fossil fuel
  26. 26. Types of fossil fuel
  27. 27. • Coal is a solid usually brown or black. • Carbon rich material. • It is one of the most important fossil fuel. • Natural resource that can be use as source of energy. • Coal is made up of carbon, hydrogen, oxygen , nitrogen and Sulphur.
  28. 28. It is believed that coal was formed from remains of trees buried inside earth crust some 500 millions years ago. Due to bacterial and chemical reaction on wood it got converted into peat. Then in result of high temperature and high pressure inside earth crust, peat got transformed into coal. Formation of coal
  29. 29. Wood bacterial chemical reaction Peat High pressure high temperature Lignite pressure Bituminous coal pressure Anthracite Formationofcoal
  30. 30. There are three main types of coal. 1. peat coal 2. Lignite coal 3. Bituminous coal 4. Anthracite coal Types of coal
  31. 31. Peat coal • It is brown in colour. • It is also called tuft. • It has very low energy.. • It consist of partially decomposed organic matter. • It is harvest as important source of fuel. • It is also use to produce electricity.
  32. 32. It Lignite coal • It is yellow or brown in colour. • It is soft. • It is formed from peat when heated at 100C • It has low energy content. • Carbon content is between 25-30%. • It has higher moisture content. • It has tendency to crumble. • It is use as fuel in electric power.
  33. 33. bituminous coal • It is also called black coal. • It is black or brown in colour. • It is medium hard. • Carbon content is between 34-86%. • It has little moisture content. • It also contain S and H. • Generally used for power generation and in steel and iron industry.
  34. 34. Anthracite coal • It is black or steel grey in colour. • It has metallic lusture. • It is hard. • Highest carbon content in between 86-96%. • It burns slowly. • It is use to heat homes. • It is also use for decorative purpose.
  35. 35. Uses of coal
  36. 36. oil • Oil is any non polar chemical substance that is viscous at ambient temperature and is hydrophobic. • Very complicated liquid mixture of hydro carbons. • Almost always contain dissolved natural gas as well.
  37. 37. How oils are formed • As diatoms died they fell into the sea floor. • They were buried under sediments and rocks . The rock squeezed diatoms and the energy in their bodies could not escape. Carbon eventually turned into oil under pressure and heat.
  38. 38. Types of oil there are two types of oils. 1. Organic oil 2. Mineral oil
  39. 39. Organic oil • Organic oil are produce in remarkable diversity by plants, animals and other organisms through natural metabolic process
  40. 40. Mineral oil Mineral oil is organic but it is called mineral instead of organic because it is obtained in the vicinity of rocks, underground traps and sands.it also refers to several specific distillates of crude oil. Mineral oil iscalled petroleum when it is in refined form. When extracted from rocks it appears as blackish colour called crude oil.
  41. 41. Applications of oil 1. Cooking and food preparation. 2. Flavoring and modifying texture of food. 3. Cosmetics. 4. Painting 5. Heat transfer 6. Lubrication
  42. 42. Natural gas • It is lighter than air. • Mixture of low boiling hydrocarbons. • Mixture primarily consisting of methane with other hydrocarbons. Carbon dioxide , nitrogen and hydrogen supplied. • Formed by decomposition of organic matter. • It is highly flammable.
  43. 43. Natural gas is found deep underground natural rock formation or associated with other hydrocarbon reservoirs in coal beds. Petroleum is another resource found in approximately to and with natural gas. Natural gas
  44. 44. Uses of natural gas Natural gas have many uses • Power generation • Domestic use • Manufacturing chemical Fertilizer • Aviation • Production of synthetic Material
  45. 45. Advantages of fossil fuel There are manys advantages of fossil fuel • Large amount of electricity can be be generated fairly cheaply. • Transporting of oil and Gas to power station is easy. • Fossil fuels are very easy to find. • Powerstations that use fossil fuel can be constructed at Almost any direction.
  46. 46. Drawbacks • The main drawback or fossil fuel is pollution. • The burning of Fossil fuel produce carbon dioxide Which contribute green house effect. • It also produce sulphur dioxide That contribute to acid rain. • Mining coal can be difficultand dangerous. • Strip mining damage large area of land. • Coal fixed Power station need large amount of coal. • Oil may contain cancer causing compound eg.benzene.
  47. 47. NUCLEAR FUEL
  48. 48. NUCLEAR FUEL • Material that can be used in a nuclear reactor to generate energy or electricity. OR • Used in nuclear reactor to sustain a nuclear chain reaction. • These fuels are fissile, most common are URANIUM-235 and PLUTONIUM-239. • Nuclear fuel cycle • Nuclear fuel is said to be efficient if it produces a lot of energy and a very little bit of pollutants. obtaining Refining Using
  49. 49. Nuclear energy is produced Naturally For example, sun and other stars make heat and light by nuclear reactions. Man-made  Machines called nuclear reactors(part of nuclear power plants) provide electricity.  Explosions of atomic and hydrogen bomb.
  50. 50. Nuclear energy is produced in two different ways  Heavy elements or large nuclei are split into fragments to release energy.  Fragments of comparable mass.  Light elements or small nuclei are combined to make a larger one nuclei/ to release energy.  Mass of larger nuclei is smaller than sum of the mass of smaller nuclei. Nuclear Fission Nuclear Fusion
  51. 51. Nuclear Fission
  52. 52. Nuclear Fusion
  53. 53. A process in which neutrons released in fission, produce an additional fission in at least one further nucleus. This nucleus in turn produces neutrons, and the process repeats. Nuclear Chain Reaction
  54. 54. Nuclear Chain Reaction vv v
  55. 55. Alpha Particles Positively charged particles and heavy as compared to other particles. Nuclear Radiations
  56. 56. Beta Particles Negatively charged particles and more penetrating as compare to alpha. Gamma Rays No charge highly penetrating radiations.
  57. 57. The known fissile materials are Uranium-233 Uranium-235 Plutonium-238 Plutonium-239 Plutonium-241 Fission Nuclear Fuels
  58. 58.  The most often used fuels are U-235 and Pu-239.  The only Fissionable Nuclear Fuel occurring in nature is URANIUM, of which is 99.3% is U-238 and 0.7% is U-235.  Pu-239 and U-233 can be produced artificially from U-238 and Th-232.  Th-232 needs fast moving neutrons to start the chain reaction.
  59. 59. c Fusion Nuclear Fuels Fusion reactions are induced by a mixture of the hydrogen isotopes DEUTRIUM (H-2) and TRITIUM (H-3), forming heavier HELIUM nucleus. Need extremely high temperature and pressure. Reaction yields 1.76MeV energy.
  60. 60. Advantage and disadvantages of nuclear energy
  61. 61. Advantages of nuclear energy 1. Lower green house gas emission  It has been calculated, the emissions of the Greenhouse gases have reduced for nearly half due to use of Nuclear Power.
  62. 62. 2. Powerful and efficient: Advancement in technologies has made it more viable option than others. This is one of the reasons that many countries are putting huge investment in Nuclear Power.
  63. 63. 3. Reliable Nuclear energy can be produced from nuclear power plants even in the cases of rough weather conditions.
  64. 64. 4. Cheap Electricity The cost of URANIUM which is used as a fuel, is quite low. Set up cost of nuclear power plant is relatively high while running cost is low. Average life of nuclear reactor is range from 4-60 years depending upon its usage
  65. 65. 5. Supply Nuclear energy is widely available, has huge reserves and expected to last for another 100 years while coal, oil and natural gas are limited and are expected to vanish soon.
  66. 66. 6. Easy to Transport Production of nuclear energy needs very less amount of raw material. Only about 28 g of Uranium releases as much energy as produced from 100 metric tons of coal. Since, it requires in small quantities, transportation fuel is much easier than fossil fuels.
  67. 67. 1. Radioactive waste When the Uranium has finished splitting, the resulting radioactive byproducts need to be removed. Disadvantages of nuclear energy
  68. 68. 2. Raw materials Uranium is naturally unstable element. That's why, special precautions must be taken during the mining, transporting and storing of the Uranium.
  69. 69. 3. Fuel Availability Unlike fossil fuels which are available to most of the countries, Uranium is very rare resource and exist in only few of the countries
  70. 70. 4. Non-renewable Energy Nuclear energy is an alternative energy but not a renewable energy, as Uranium is non-renewable
  71. 71. 5. Hot Target for Militants Nuclear energy has immense power. Today, nuclear energy is used to make weapons. If these weapons go into the wrong hands, that could be the end of this world.
  72. 72.  A nuclear reactor produces and controls the release of energy from splitting the atoms of certain elements.  The energy released is used as heat to make steam to generate electricity. NUCLEAR REACTOR
  73. 73. Types of Nuclear Reactor Neutrons , generated during nuclear fission reactions to produce radioisotopes, that are going to be used in other applications of nuclear energy or materials. NUCLEAR REASERCH REACTOR
  74. 74.  These are based on the use of thermal energy generated in fission reactions.  This reactor is used to generate the electricity in power plant. TYPES OF NUCLEAR REACTOR NUCLEAR POWER PLANT
  75. 75. Pressurized water Reactor (PWR)  PWR is the most used in the world.  This nuclear reactor uses enriched Uranium as oxide form as nuclear fuel.  Water under high pressure can evaporate without reaching the boiling point. i.e. at temperature greater than 100c. TYPES OF NUCLEAR REACTOR
  76. 76. Boiling Water Reactor (BWR) •BWR is also used frequently. •Water is used as coolant and moderator. •Nuclear fuel is enriched Uranium in oxide form. •Thermal energy generated by the chain reaction is used to boil water. TYPES OF NUCLEAR REACTOR
  77. 77. Requirement of a good fuel Moderate ignition temperature. Low moisture content. Combustion should be controllable. Easy to transport and readily available at low cost.
  78. 78. Principle of Combustion  Combustion refers to the rapid oxidation of fuel accompanied by the production of heat, or heat and light. Complete combustion of a fuel is possible only in the presence of an adequate supply of oxygen. COM BUST ION
  79. 79. 3T’S of combustion The objective of good combustion is to release all of the heat in the fuel. This is accomplished by controlling the "three T's" of combustion which are (1)Temperature high enough to ignite and maintain ignition of the fuel (2) Turbulence or intimate mixing of the fuel and oxygen, and (3) Time sufficient for complete combustion
  80. 80. CH4+2O2 CO2+2H2O
  81. 81. No smoke or ash after combustion High thermal efficiency High calorific value Advantages of gaseous fuel
  82. 82. Disadvantages of gaseous fuel Highly inflammable so higher chances for fire hazards are high Since gas occupy large Volume , they require Large storages tanks
  83. 83. No ash after burning Require less storage space High calorific value Combustion is uniform Advantages of liquid fuel
  84. 84. Comparatively costlier Evaporate during storage Unpleasant odour during incomplete combustion Special type of burners are required for effective combustion Dis Advantage s of liquid fuel
  85. 85.  Crude petroleum is defined as a naturally occurring mixture, consisting of hydrocarbons and derivatives of hydrocarbons which is removed from the earth in liquid state.  Petroleum (Petra=rock, oleum=oil ) also known as rock oil or mineral oil.
  86. 86.  Petroleum is formed from the fossilized remains of ancient plants and animals by exposure to high heat  And pressure in the absence of oxygen in the earth’s crust over hundreds of millions of years.  Petroleum is extract from underground deposits at a depth of 500-1500 feet at various places.
  87. 87. Composition of typical crude oil z zz z83-87% HYDROGEN 11-14% NITROGEN 0-05% CARBON
  88. 88. The crude petroleum falls into three main classes: 1. The first yields on distillation a residue consisting mainly of paraffin wax and is known as a paraffin base crude. 2. The second leaves a black, lustrous residue of asphalt, and is known as an asphalt-base crude. 3. The third, leaving both asphalt and paraffin as a residue, is known as a mixed-base crude. CLASSIFICATION
  89. 89. • Nearly all crude petroleum contain nitrogen and sulfur.  The nitrogen may vary from only a trace up to 1 percent and over and is practically always present in the form of complex organic bases.  Sulfur, though rarely absent, is usually present in only small amounts.  Crystalline sulfur also has been separated from a number of crude petroleum. COMPOSITION
  90. 90. Compounds found in petroleum • CnH2n+2. • CnH2n • CnH2n-2 • CnH2n-1 • CnH2n-6 • CnH2n-8 • CnH2n-10 • CnH2n-12 • CnH2n-14
  91. 91. Uses • Transportation • Lubricants Of • Heating & lighting • Industrial power petroleum • Petro-chemical industry • Use of by-products
  92. 92. COPMOSITION OF NATUREL GAS
  93. 93. 1. The manufacturing process of gasoline 2. Fractional distillation 3. Refining petroleum 4. Reforming of petrol 5. knocking
  94. 94. 2. After a possible reservoir is found the area must e test drill. Core sample are taken to confirm rock formation. Sample are chemically analyze. Exploration 1. The first step is to find petroleum(Parent ingredient). Crude oil is trapped in areas of porous rock or reservoir rock
  95. 95. 2 0 1 8 3. Crude oil recovered through well into the rock. Holes are made rotary drillers which bore a hole as water is added. Water and soil create a thick mud that hold back the oil and prevent it from “gushing’’. 4. To recover the oil complicated system of pipes is installed into the well. Natural pressure of reservoir rock brings oil out of well into pipes. These are connected to a recovery system.
  96. 96. Fractional Distillation »Long chains of molecules in crude oil must be separated into smaller chains of refine fuels including gasoline, in a petroleum refinery. This process is called fractional distillation.
  97. 97. Refining petroleum • ‘’It is the process of separation of crude oil into different useful fractions on the basis of their B.P’’. It is done by two processes. 1.Cracking 2.polymerization
  98. 98. • It is the process of decomposition of higher molecules(higher boiling) into lower molecular weight hydrocarbons. • Cracking process involves breaking of C-C and C-H bond • It produces low alkanes and alkenes. • A small amount of hydrogen and hydrogen are also produced.
  99. 99. 2.Catalytic cracking: Carried out in the presence of a catalyst(Al2O3+SiO2) at much lower temperature and pressure. 1. Thermal cracking: Carried out at high temperature and pressure in the absence of catalyst.
  100. 100. • The increase in octane number of straight run gasoline occurs through structural modifications such as conversion of straight hydrocarbon into branched, cyclic, and aromatic hydrocarbons. Reforming process: • The straight run gasoline is preheated to remove S and N content to avoid Pt catalyst being poisoned. • Mixed with hydrogen and preheated to 5000 C.
  101. 101. Reforming reactions •Isomerization: The conversion of straight chain hydrocarbon into branched chain. •Dehydrogenation: dehydrogenation of cycloalkanes to produce aromatic compounds.
  102. 102. • In an internal combustion engine sharp sound caused by premature combustion of parts of compressed air-fuel mixture in the cylinder. Cause of knocking: • In properly functioning engine charge burns with flame front progressing smoothly from point of ignition across combustion chamber.
  103. 103. • By a suitable change in engine design. • Using anti-knocking agent. • Using high rating gasoline.
  104. 104. THANKS FOR LISTENING

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