PPT

• Fuel


  A fuel is any solid, liquid, or gaseous substance that may be combusted (burned) to produce heat or work.
• Forms of Fuel

  • coal in power plants to generate electricity.
  • gasoline to run our cars.
  • natural gas or heating oil to warm our homes.
• Forms of Fuels

  • propane, charcoal, or wood to cook our food at a summer barbecue.
  • wax to provide light for a romantic candlelit dinner.
• Flame


  Combustion creates a difference in energy between the reactants

  and products, releasing that energy as heat and light, which we see as a flame.
• Flame - Combustion creates a difference in energy between the reactants

  and products, releasing that energy as heat and light, which we see as a flame.
• Prehistory where solids such as grass and straw were burned for heat.
• Ancient Civilizations, use of coal where it was used to isolate copper from ore in northeastern China as early as 1000 BC.
• Industrial Revolution in the late 18th century sparked the large-scale use of coal for steam engines and steelmaking.
• Mid-19th century in the U.S., growth of the petroleum industry and widespread use of petroleum for transportation, electricity, heating,

  and plastics production.
• Currently, the world’s energy needs are provided by burning fossil fuels, coal, and oil.
• ignites easily at a low temperature and produces a large quantity of heat during its combustion.
• inexpensively isolated and have properties that allow for their safe and efficient storage or transport.
• should leave little residue behind after being burned, and produce by-products that are not harmful to human health or the environment.
• Fossil Fuels

  these so-called fossil fuels are not the prehistoric

  remains of dinosaurs.
• burning fossil fuels for energy fails to meet the

  criteria of sustainability in two ways:

  1. the fuels themselves are nonrenewable.
  2. the waste products of combustion have adverse effects on our environment, both today and in the future.
• Necessary Requirements to Generate a

  Fire:

  1. a source of heat,
  2. a fuel, and
  3. an oxidizer.
• The identity of the products will differ, depending on the fuel and oxidizer used for combustion. The great majority of fuels are hydrocarbons,

  compounds made up only of the elements hydrogen and carbon.
• Characteristics of a Good Fuels

  A good fuel should satisfy the following requirements:
• Characteristics of a Good Fuels

  It should have a high calorific value i.e., it should evolve a large

  amount of heat when it is burnt.
• Characteristics of a Good Fuels

  Its moisture content should be low so that its heating value should

  be high.
• Characteristics of a Good Fuels

  An ideal fuel should have moderate ignition temperature.
• Characteristics of a Good Fuels

  An ideal fuel should have moderate ignition temperature.
• Characteristics of a Good Fuels

  It should not produce harmful products like CO2, SO2, H2S and other

  poisonous gases on burning; they pollute the atmosphere.
• Characteristics of a Good Fuels

  A fuel should have low content of non-combustible matter in the form of

  ash or clinker. Since the presence of non-combustible matter will enhance the cost of storage, handling and disposal of waste.
• Characteristics of a Good Fuels

  • The combustion of fuel should be controllable so that it can be started or stopped.
  • It should not give any offensive odor
  • It should have moderate velocity of combustion.
• Classification of Fuels

  According to the physical state in which they exist in nature - solid, liquid, gaseous, and

  According to the mode of their procurement -natural and manufactured.
• Classification of Fuels

  Natural Fuels refers to the fuel material that has not been created or altered through manufacturing or chemical means.
• Manufactured Fuel refers to any fuel derived from natural resources like crude oil, coal and natural gas.
• Solid Fuels

  
• Liquid Fuels

  
• Gaseous Fuels

  
• Solid Fuel

  Solid fuels are mainly classified into two categories, i.e. natural fuels,

  such as wood, coal, etc. and manufactured fuels, such as charcoal,

  coke, briquettes.
• Advantages of Solid Fuel

  • They are easy to transport
  • They are convenient to store without any risk of
  • spontaneous explosion.
  • Their cost of production is low.
  • They possess moderate ignition temperature.
• Disadvantages of Solid Fuel

  • Their ash content is high.
  • Their large proportion of heat is wasted.
  • They burn with clinker formation.
  • Their combustion operation cannot be controlled
  • easily.
  • Their cost of handling is high.
• Liquid Fuel

  The liquid fuels can be classified as Natural or crude oil, and Artificial or

  manufactured oils.
• Advantages of Liquid Fuel

  • They possess higher calorific value per unit mass than solid fuels.
  • They burn without dust, ash, clinkers, etc.
  • Their firing is easier and also fire can be extinguished
  • easily by stopping liquid fuel supply.
  • They are easy to transport through pipes.
  • They can be stored indefinitely without any loss.
  • They are clean in use and economic to handle.
  • Loss of heat in chimney is very low due to greater
  • cleanliness.
  • They require less excess air
  • for complete combustion.
  • They require less furnace space for combustion.
• Disadvantages of Liquid Fuel

  • The cost of the liquid fuel is relatively much higher as compared to solid fuel.
  • Costly special storage tanks are required for storing liquid fuels.
  • There is a greater risk of five hazards, particularly, in case of highly inflammable and volatile liquid fuels.
  • They give bad odor.
  • For efficient burning of liquid fuels, specially constructed burners and spraying apparatus are required.
• Petroleum - Basic natural fuel. Dark greenish brown, a viscous

  mineral oil, found deep in earth’s crust.
• Petroleum - It is mainly composed of various hydrocarbons (like straight chain paraffins, cycloparaffins or napthenes, olefins, and aromatics) together with small amount of organic compounds containing oxygen, nitrogen, and sulfur.
• Petroleum composition