Production ethanol: fermentation vs. ethene and steam

Ethanol is the type of alcohol found in alcoholic drinks such as wine and beer. It's also useful as a fuel. For use in cars and other vehicles, it is usually mixed with petrol.
Ethanol molecules contain carbon, hydrogen and oxygen atoms
1. C2H5OH
Ethanol can be made by reacting ethene (from cracking crude oil fractions) with steam. A catalyst of phosphoric acid is used to ensure a fast reaction.
1. Ethene is made from crude oil, which is a non-renewable resource. It cannot be replaced once it is used up and it will run out one day.
  1. This process needs conditions of 300 degrees and very high pressure which uses a lot of energy,but produces 100% pure alcohol
Another way ethanol can be produced is fermentation
1. Sugar from plant material is converted into ethanol and carbon dioxide by fermentation.
2. The enzymes found in single-celled fungi (yeast) are the natural catalysts that can make this process happen.
  1. C66H12O6 → 2C2H5OH + 2CO2
3. Unlike ethene, sugar from plant material is a renewable resource.
4. The conditions needed for this reaction is only 30-40 degrees meaning it doesn't need a lot of energy
  1. Alcohol is impure therefore has to be distilled further which takes a lot of time

Resource summary

	Created by tom_gill99 almost 13 years ago