Ethanol Production

Question 1

How are alcohols produced

Answer 1

By the hydration of alkenes

Question 2

What type of method is the hydration of alkenes

Answer 2

Industrial method

Question 3

Give the conditions required for the hydration of alkenes

Answer 3

• Steam
• Acid catalyst

Question 4

What are the conditions required to produce ethanol via the hydration of ethene

Answer 4

• 300C
• Pressure at 60atm
• Phosphoric acid catalyst

Question 5

Draw the mechanism for the hydration of ethene

Answer 5

Check physical flashcards for answers

Question 6

Give another process by which ethanol can be produced

Answer 6

Fermentation

Question 7

How is ethene produced?

Answer 7

Cracking of heavy fractions of crude oil

Question 8

What is the raw renewable material used in fermentation and why is this important

Answer 8

• Glucose
• Crude oil supplies will run out and petrochemicals like ethene will become expensive

Question 9

Describe the industrial production of ethanol by fermentation of glucose and give the conditions

Answer 9

• Exothermic process
• Requires enzymes yeast
• Anaerobic conditions ( without oxygen)
• Glucose produces ethanol and carbon dioxide
• Enzyme works best at 30C-40C
• Ethanol is separated from the rest of the mixture by fractional distillation
• Low-tech, cheap equipment and renewable resources
• Fractional distillation for purification takes extra time and money

Question 10

How does temperature affect the enzyme yeast and the rate of reaction

Answer 10

• Cold temperatures will make the reaction slow
• Too hot temperatures will denature the enzyme

Question 11

Give an example of a biofuel

Answer 11

Ethanol

Question 12

Why is ethanol described as a biofuel?

Answer 12

• Used as a fuel
• Found in countries with low oil reserves (Brazil)
• Sugars from sugar cane are fermented and used to produce ethanol
• Ethanol added to petrol
• Sometimes called bioethanol

Question 13

What is a biofuel

Answer 13

• A fuel that’s made from biological material that’s recently died

Question 14

What are the advantages and disadvantages of Biofuels over fossil fuels

Answer 14

Advantages
• Renewable energy source we and more sustainable
• Carbon neutral based on equations

Disadvantages
• Petrol car engines will have to be modified to use fuels with high ethanol concentration
• Land used to grow crops for fuel, that land can’t be used to grow food

Question 15

Why can bioethanol production be classed as carbon neutral

Answer 15

• As plants grow, they take in the same amount of carbon dioxide as burning the ethanol you produce from them gives out

Question 16

Give the three equations and name them that prove that ethanol is carbon neutral

Answer 16

Check physical flashcards for answers

Question 17

Why can’t bioethanol be classed as carbon neutral?

Answer 17

Fossil fuels will need to be burned to power the machinery used to make fertilisers for the crops, harvest the crops and refine and transport the bioethanol. Burning the fuel to power this machinery produces carbon dioxide

Question 18

Biofuel ethanol is purified by fractional distillation. Is this statement correct?

Answer 18

Yes