Alkanes

• Alkanes are saturated hydrocarbons
• Petroleum is a mixture consisting mainly of alkane hydrocarbons that can be separated by fractional distillation
• Cracking means breaking the C-C bonds in alkanes resulting in shorter alkanes and alkenes.
• Thermal cracking is cracking on long chained alkanes into alkenes and shorter alkanes using high pressure and high temperature
• Catalytic cracking is another process to break long chained hydrocarbons to shorter hydrocarbons using high temperature and slight pressure. As well as using a zeolite catalyst to produce aromatic compounds and motor fuels
• Economic reasons for cracking

  • Long chains alkanes have a low demand and so not valuable
  • Products are in higher demand and are more valuable
  • Make more useful fuels
  • Makes the starting material for polymers
• Pollutants of combustion of hydrocarbon fuels

  • Soot
  • Carbon monoxide
  • Carbon dioxide
  • Nitrogen oxides
  • Sulfur dioxide
  • Water vapour
  • Unburnt hydrocarbons
• Nitrogen oxides and sulfur dioxide leads to acid rain
• Soot causes global dimming and respiratory problems while unburnt hydrocarbons also cause respiratory problems and causes global warming
• Nitrogen oxides cause respiratory problems, acid rain and photochemical smog
• Catalytic converter

  • Uses a platinum catalyst
  • On a ceramic honeycomb structure
  • Very small amounts of metal
  • It converts CO, nitrogen oxides and unburnt hydrocarbons into less harmful gases as they react together
• Flue gas desulfurisation

  It's the removal of sulfur dioxide by adding calcium oxide or calcium carbonate into the water
• Carbon dioxide and other greenhouse gases traps infrared radiation so that heats up the earth's atmosphere