Production of ethanol

What are the 2 types of production of ethanol

Hydration of ethane

OR

Fermentation

What is the reaction of hydration of ethene ?

Ethene + steam —> ethanol

What are the conditions for hydration of ethene ?

H3PO4 catalyst

300 *C

60 - 70 atm

What are the pro for hydration of ethene ?

Fast reaction

Continuous reaction

Pure final ethanol + 100 % atom economy

What are the cons of hydration of ethene ?

Ethene is non - renewable

High temp + pressure

$ process

Draw the mechanism of hydration of ethene

What happens in the process fermentation hint : glucose

Break down of glucose into ethanol + CO2 in anaerobic conditions

C6 H12 O6 —> Yeast —→ 2 C2 H5 OH + 2 CO2

What are the conditions of fermentation

Temp : 35 *c

Anaerobic conditions

Yeast enzyme

Why these conditions ?

35 *c → enzyme will denature if temp too high or temp too low reaction will be slow

Anaerobic : to prevent oxidation occurring ethanol + [ O ] → ethanoic acid

Yeast : replace the oxygen + allows for breakdown of glucose without oxygen

What are the pro of fermentation ?

Renewable

Low tech

Cheap

What are the conditions fermentation ?

Slow rate + 51.1 % atom economy

Batch process

need to distil to an ethanol

What does batch process means ?

Series of operation are accredited out over a period of time on a separate identifiable item or parcel of material

Where does Biofuels + fuels come from ?

Biological source

Biofuels + fermentation ?

It’s carbon neutral since the same amount of CO2 is absorb in photosynthesis of the plant and when we produce ethanol form the biofuels + burn the ethanol

Why is not all carbon neutral ?

But… fossil fuels will be have to burn to power machines to make fertilisers to harvest crops

And refinery equipment needs electric to power

And transport needs fuels to be burnt

What is the definition of of carbon neutral

there is a balance between carbon emissions and carbon absorption, resulting in a net zero carbon footprint.

How many of moles of CO2 is absorbed in photosynthesis

6 moles of CO2

6 CO2 + 6 H2O → C6 H12 O6 + 6H2O

How many moles of CO2 is released in fermentation of glucose

2 mole of CO2

C6 H12 O6 → 2 C2 H5 OH + 2 CO2

How many moles of CO2 is released in combustion of ethanol

4 mole of CO2

2 C2 H5 OH + 6 O2 → 4 CO2 + 6 H2O

How many moles of CO2 are totally released ? In fermentation + combustion

6 mole of CO2