fractional distillatoons

• • the crude oil is heated to 400 degrees
  • most fractions evaporate and become vapours. the residue doesn't boil and flows to the bottom of the column
  • hot vapours rise up the column and cool down
  • when the vapours cool to their boiling point, they condense and flow out of the column
  • those with lower boiling points rise further before cooling down
  • refinery gases do not cool down to their boiling point so remain as gases
• fractional distillation