3.11 Evaluate the factors relevant to the choice of method used in the manufacture of ethanol, for example the relative availability of sugar cane and crude oil

HYDRATION OF ETHENE

• Pros
• The process is continuous
• Only one product is produced (no need to separate them afterwards)
• Fewer workers are needed
• Fast process
• Cons
• Comes from non-renewable, expensive sources (crude oil, cracked to make ethene)
• High temperature and pressure is needed
• A lot of energy is used

FERMENTATION OF SUGARS

• Pros
• Sugar is a renewable source
• It is also widely available and cheap
• Normal pressure and a warm environment used
• Cons
• Two products are produce (they are impure and need to be purified)
• It is a batch process (stop-start)
• A lot of workers are needed
• It is a slow process