AQA A Level Chemistry复习笔记7.3.3 Biodiesel




  • Biodiesel is made from renewable vegetable oils rather than non sustainable petrochemicals
  • Natural triglyceride oils are converted to esters of methanol, which makes them less viscous
  • Biodiesel made from rapeseed oil for example is produced by transesterification
    • The triglyceride is converted, or transesterified, into the less viscous fatty acid methyl ester (FAME) using methanol
    • Acids and alkalis can both be used to catalyse the reaction
      • An acid works by protonating the carbonyl group
      • An alkali works by deprotonating the alcohol / methanol
      • However, it is more common to use an alkaline catalyst such as NaOH / KOH


    • The transesterification is reversible, so an excess of methanol is used to drive the equilibrium to the right
    • Under optimum conditions this process can produce a very successful yield of 98%



Transesterification forming methyl esters