Are there really two ways of making ethanol?

Question

I was told that you could make ethanol (for fuel, like biofuel) in two different ways... What are they? Which one is better?

Answer 1

here is one way and it is not to be recommended

for the planets or our sakes

http://answers.yahoo.com/question/index;...

Answer 2

I know of only one way.  I answered a similar question on here a couple of weeks ago, so here is the link:

http://uk.answers.yahoo.com/question/ind...

Answer 3

fermentation, and some other reaction between an ester and an alkene i think, i'm not sure

oh here's some information from a website:

There are several ways to make ethanol from biomass. The most commonly used processes today use yeast to ferment the sugars and starch in corn. Corn is the main ingredient for ethanol in the United States due to its abundance and low price. Most ethanol is produced in the corn-growing states in the Midwest. The starch in the corn is fermented into sugar, which is then fermented into alcohol. Other crops such as, barley, wheat, rice, sorghum, sunflower, potatoes, sugar cane and sugar beets can also be used to produce ethanol.

Sugar cane and sugar beets are the most common ingredients for ethanol in other parts of the world. Since alcohol is created by fermenting sugar, sugar crops are the easiest ingredients to convert into alcohol. Brazil, the country with the world's largest ethanol production, makes most of its ethanol this way. Today, many cars in Brazil operate on ethanol made from sugar cane.

A new experimental process which breaks down cellulose in woody fibers, is called "cellulosic ethanol". With this process we can make ethanol from trees, grasses, and crop wastes. Trees and grasses need less energy than grains, which must be replanted every year. Scientists have developed fast-growing trees that grow to size in ten years. Many grasses can produce two harvests a year for many years. Someday, you may find yourself driving by huge farms that are not producing food or animal feed, but feedstock for ethanol. Feedstock is the raw material used to make a product.

Answer 4

Ethanol can be made from fermentation of plant sugars or starch.

It is also made industrially from natural gas/naptha (ethylene being an intermediary product, I believe it can also be made from acetic anhydride as an intermediary but don't have a reference).  In this instance it is not a biofuel as it is made from a fossil fuel.

http://chemcases.com/alcohol/alc-03.htm

Answer 5

you can make it up to 96% pure ,in which case it is still ethanol, by using only water. You can however make it 100% pure by using another chemical (cant remember the name) to make methanol. To pureify it you use fractional distilation.

Answer 6

I make quite a lot of ethanol by fermenting sugar and yeast. I have to run it through a still after fermentation but since it doesn't burn that well on it's own I make it up into spirit that I can drink by putting it through carbon filters. The first 50 to 100 mls contains methanol which in small amounts gives you a bad hang over. In large amounts will kill you so I discard that although my son found it ran his model aircraft engine very well. As a total alternative fuel to petrol it's a total waste of time and the costs are prohibitive.