Enggchem

• Fuel

  • a material which when once raised to its ignition temperature continues to burn if sufficient oxygen or air is avaible
• Fuel = carbon & hydrogen
• Fuels:

  • Solid
  • Liquid
  • Gaseous
• Classification of Coal

  • Anthracite - hardest type of coal with more carbon and energy
  • Lignite - low carbon content but high hydrogen and oxygen
  • Bituminous - falls in between the range of the 2
• Edwin Drake

  • discovered crude oil
• Petrol = 5-7 carbons in the hydrocarbon chain
• Kerosene = jets,engines, aircraft
• Diesel = vans, trucks, heavy equipment
• Natural Gas:

  • Dry = methane
  • Wet = methane, ethane, propane, butane, pentane
• Stoichiometry - branch of chemistry which deals with mass and volume relations in unit operations
• Stoichiometry = Law of Definite and Multiple Proportions
• Industrial Stoichiometry

  • the application of the laws of conservation of matter and operations of industrial chemistry
• Combustion

  • chemical reaction of a free reactant (oxygen in air) and chemical called fuel
• Gaseous Fuels

  • contain CO, light or low molecular weight hydrocarbons
• Producer Gas - generated by blasting a hot bed of coal of coke continuously with air
• Blue water gas

  • blast of air is forced through
• Carbureted water gas - water gas enriched in oil
• Blast furnace gas - byproduct of the manufacture of pig iron in blast surfaces
• Molecular Formula

  • expression of the number and the type of atoms that are present in a single molecule of a substance
  • actual formula of a molecule
• Empirical Formula

  • simplest formula
  • ratio of elements present in the compound
• Complete Combustion

  • combustible materials are completely gasified
• Incomplete Combustion

  • indicated by the presence of CO and unburned H2
  • represents a heat loss
• Theoretical Oxygen

  • oxygen required for complete oxygen
• Theoretical Air for Combustion

  • air that contains the exact amount of theoretical O2
• Crystals

  • minerals formed underground from a 3 dimensional repeating patterns of atons
• Crystallography

  • experimental science of determining the arrangement of atoms in crystalline solids
• Crystal Structure

  • description of the ordered arrangement of atoms
• atom

  • smallest constituent of ordinary matter
• ion

  • an atom or molecule that has non zero net electrical charge
• cation = +

  anion = -
• molecule

  • electrical neutral group of 2 or more atoms held together by chemical bonds
• Crystal

  • solid material in which the components atoms are arranged in a definite pattern
• Ordered Structures

  • occur from the intrinsic nature of the particles to form patterns
• Unit Cells

  • smallest group of particles in the material that constitutes the repeating pattern is the unit cell of the structure
• Crystalline Lattice - regular arrangement of atoms within a crystal
• Coordination number

  • number of atoms with each atom is in direct contract
• Packing Structure

  • percentage of the volume of the unit cell occupied by the spreres
  • high coordination = better packing efficiency
• Simple Cubic Lattice

  • has one atom at each corner
  • atoms touch along each edge
  • l = 2r
  • 1/8 of each eight atons
  • efficiency = 52%
• Body Centered Cubic Lattice

  • one atom in the center and one at each corber
  • atoms touch at a diagonal through the center
  • efficiency = 68%
• Face-centered Cubic Lattice

  • has one atom at each corner and one atom in the center of each face
  • diagonal face
  • efficiency = 74%