Production of Ethanol

• Ethanol is an alcohol with the formula CH3CH2OH
• This is the formula of ethanol

  
• Ethanol has 3 main uses:

  1. As a chemical feedstock to produce other organic compounds.
  2. As a biofuel (ethanol can be burned like petrol).
  3. Used in alcoholic drinks such as beer, wine, and spirits.
• Ethanol can be produced from ethene and steam.

  Ethanol requires a catalyst and high temperature to be made.

  
• ethanol is made from an addition reaction because the water molecule is being added to the ethene molecule.
• The conditions needed to make ethanol are:

  High temperature (300 °C), high pressure (60-70 atm), phosphoric acid catalyst.
• Advantages: Ethene is cheap and the reaction itself is cheap and efficient. 
• Disadvantages: Ethene is made from crude oil which is a non-renewable resource, so if it starts to run out it will become expensive.
• Ethanol can be produced by fermentation. Fermentation is the anaerobic respiration of sugars by yeast cells to produce ethanol and carbon dioxide.

  
• To create ethanol via fermentation it must be:

  Carried out in fermentation tanks. Requires yeast cells which have naturally occurring enzymes to catalyse the reaction. Temperatures of 30-40 °C (this is optimum temperature for the enzymes). Must be anaerobic conditions (no oxygen), so that the ethanol isn't oxidised to ethanoic acid.
• Advantages of ethanol via fermentation: The sugar/glucose used is a renewable resource so can't run out. Yeast are easy to grow.
• Disadvantages of ethanol via fermentation: The process can be relatively slow. The ethanol produced isn't pure so must be distilled by fractional distillation.
• Ethanol can be produced by fermentation.

  Why are temperatures of 30-40 °C used?

  This is the optimum temperature for the enzymes
• What is the symbol equation for ethanol produced by fermentation?

  C6H12O6 ---> CH3CH2OH + CO2