Cracking

• What is cracking used for?

  • Breaks down larger less useful alkanes to smaller more useful alkenes
• Why is cracking needed?

  The shorter chains products are economically more valuable than longer chain materials

  To meet the demand for the shorter chain hydrocarbons cracking is used
• Conditions of thermal cracking?

  Temperature = 700-1200 k

  Pressure = up to 7000 Kpa
• Products formed by thermal cracking?

  Higher proportion of alkenes is produced
• Conditions of catalytic cracking?

  Temperature = 720 K

  Pressure = A slight pressure (higher than atmospheric pressure)
• What is the catalyst used in catalytic cracking?

  Zeolite
• Products formed by catalytic cracking?

  • Branched alkanes
  • Cycloalkanes
  • Aromatic hydrocarbons