production of ethanol

• hydration :

  • temperature: high
  • pressure: high
  • catalyst: concentrated phosphoric acid
  • batch/ continuous: continuous
  • reagent: water
• markpoints for hydration of ethene:

  m1: curly arrow from double bond to H+ ion

  m2: alkane and carbocation intermediate formed, curly arrow from middle of e- on O in H2O to carbocation intermediate on C next to C with H added

  m3: positive charge on O in H2O which is now bonded to ethanol

  m4: curly arrow from bond between O and H to positively charged O
• fermentation:

  • temperature: 35 degrees celsius
  • catalyst: yeast
  • batch/continuous: batch
  • anaerobic, no presence of oxygen
• how can ethanol produced by fermentation be purified?

  through fractional distillation
• Industrial production of ethanol:

  -advantages:

  • continuous process (economic)
  • 100% yield pure product (economic)
  • fast rate of reaction (economic)
  • cheap, depends on oil cost (economic)
  • 100% atom economy (environment)
• Industrial production of ethanol:

  -disadvantages:

  • high tech uses lots of energy (economic)
  • higher cost due to high temp and pressure (economic)
  • uses non renewable resources (environmental)
  • CO2 emitted during production (environmental)
• Fermentation production of ethanol:

  -advantages:

  • low energy costs (economic)
  • uses a renewable resource, sugar (environmental)
  • carbon neutral process (environmental)
  • produces biofuel (environmental)
• Fermentation production of ethanol:

  -disadvantages:

  • batch process (economic)
  • impure product, 12% product, need to distil to concentrate ethanol (economic)
  • slow rate of reaction (economic)
  • low atom economy (environmental)
  • produces CO2 (environmental)
  • creates moral problem if land should be used for food or fuel
• biofuel: fuel made from renewable biological resources
• carbon neutral: no net increase in CO2 in the atmosphere