Organic Chemistry: Ethanol Flashcards
1
Q
Name two process that ethanol is produced by
A
- fermentation
- direct hydration of ethane
2
Q
Describe process of fermentation
A
- yeast added to sugar/starch solution in anaerobic conditions and temp of 25-40c
- enzymes in yeast convert sugar to ethanol and CO2
3
Q
How is ethanol obtained after fermentation?
A
- filtered to remove excess yeast
- fractional distillation
4
Q
Describe process of direct hydration of ethane
A
- mixture of ethane and steam passed over phosphoric acid at temp of 300c and atm pressure of 60-70
- condensed as a liquid
- unreacted ethane recycled back into process
5
Q
Ethanol production: resources
A
- fermentation: uses renewable resources (e.g. sugar)
- hydration: uses non-renewable resources (one crude oil is used up there will be no more
6
Q
Ethanol production: type of process
A
- fermentation: batch process at low temp - cheap equipment, but high labour costs
- hydration: continuous process at high temp and pressure using expensive equipment, but low labour costs
7
Q
Ethanol production: rate of reaction
A
- fermentation: very slow - takes several days for each batch
- hydration: very fast
8
Q
Ethanol production: quality of product
A
- fermentation: dilute solution of ethanol needing further processing
- hydration: produces pure ethanol
9
Q
What catalyst is used to dehydrate ethanol?
A
hot aluminium oxide- provides large SA for reaction
10
Q
What can dehydration be used for?
A
manufacturing ethene for production of polyethene
