Ethanol Fuels

Quiz

How Much Do You Know About Ethanol Fuels?

Question 1

Ethanol is produced from starches, which are essentially just sugars? So why can’t we use animal fats to produce ethanol-type fuels?

Animal fats contain too many other contaminates.
The sugars inside animals, cannot be used in fermentation.   
Fat molecules do not contain sugar.
Animal fats can be used to produce a kind of fuel.


Question 2

Ethanol is the same as alcohol, so if E100 became widely used why wouldn’t we see people siphoning off their gasoline tanks for a drink?

Ethanol is mixed with gasoline during production in order to make it unfit for consumption.  
During transport and storage, the ethanol would become mixed with leftover gasoline in storage tanks.
Ethanol is so corrosive people wouldn’t dare drink it.
Tougher laws against siphoning ethanol will be needed to prevent such occurrences.


Question 3

Ethanol has some major drawbacks, some of which include increased soil degradation. Why would this occur?

Cellulose ethanol would use corn stocks and other plants that otherwise would be plowed under to regenerate the land.

Corn production damages soil quality.
Increasing ethanol production would require clear cutting of forests to provide the land needed for crops.
All of the above.

Question 4

"This makes no sense!" Todd cries after reading the section on ethanol production.  "How can we obtain more energy than we put into something?" How would you answer him?

"You're right, this is just like a perpetual motion machine, the numbers must be wrong."
"'Free' energy sources, like the energy obtained from the sun, are not considered."
"During the fermentation process, the yeast adds energy to the system."
"Part of the production energy is reduced since one of the bi-products can be used as feed."
 

Bonus Question: Try this question out if you like a challenge!

Amy reads a study that states unequivocally that litre per litre, an E85 blend of ethanol produces 30% less carbon dioxide than regular unleaded gasoline.  She then brags to her friends her flexible fuel vehicle, which gets 15 km/L on regular unleaded gasoline produces less carbon dioxide than her friend’s hybrid which gets 20 km/L on the same. She reasons that she expends 1.33 L of fuel for every L that her friend does in their hybrid.  Since E85 produces 30% less CO2, 0.7 times 1.33 = 0.93, so 1.33 L of ethanol only produces the same amount of carbon dioxide as 0.93 L of gasoline in the hybrid.  Hence, her vehicle is more environmentally friendly using E85 than her friend's is on regular gasoline.

Do you agree with Amy?  Or is there is a flaw in Amy’s logic, and if so, what is it? Also, try to calculate if it is cheaper to use E85 than regular unleaded gasoline for Amy by searching online for ethanol prices.


Check out the answers here.