Production of Ethanol Flashcards
(11 cards)
what are the two ways ethanol can be produced?
- ethene and steam
- fermentation
how can ethanol be produced from ethene and steam?
- ethene is produced from crude oil by cracking
- ethene will react with steam to make ethanol
- this is an addition reaction because water is added to the molecule
what temperature and pressure does the ethene and steam reaction need?
temperature = 300 degrees celcius
pressure = 65 atmosphere
what catalyst is used during the ethene and steam reaction?
phosphoric acid
advantages of ethene and steam reaction
- makes pure ethanol
- can run continously
- ethene is fairly cheap and not much is wasted
disadvantages of ethene and steam reaction
- crude oil is non-renewable resource and will start to run out fairly soon
- conditions require lots of energy
how is ethanol produced by fermentation?
- the raw material for fermentation is sugar e.g. glucose
- sugar is converted into ethanol using yeast
- yeast cells contain can enzyme, which are naturally occuring catalysts, they speed up reactions
what is the temperature needed for fermentation?
30 degrees celcius - fermentation happens fastest at this temperature
- at lower temperatures the reaction slows down
- if its too hot, the enzyme in the yeast denatures and the reaction would stop
why is it important to keep the mixture in anaerobic conditions in fermentation?
oxygen converts the ethanol to ethanoic acid
advantages of fermentation
- the raw materials are renewable resources
- sugar cane is grown as a major crop in several parts of the world
- yeast is easy to grow
- conditions not energy intensive
disadvantages of fermentation
- makes impure ethanol
- must be done in individual batches
- ethanol isn’t very concentrated and needs to be distilled to increase strength and purified
