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
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.
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.
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
Sugar from plant material is
converted into ethanol and carbon
dioxide by fermentation.
The enzymes found in single-celled fungi (yeast) are the
natural catalysts that can make this process happen.
C66H12O6 → 2C2H5OH + 2CO2
Unlike ethene, sugar from plant
material is a renewable resource.
The conditions needed for this reaction is only 30-40 degrees
meaning it doesn't need a lot of energy
Alcohol is impure therefore has to be distilled further which
takes a lot of time