Ethanol is the intoxicating agent in fermented and distilled liquors; used pure or denatured as a solvent or in medicines and colognes and cleaning solutions and rocket fuel; proposed as a renewable clean-burning additive to petrol. In Australia we use ethanol as an alternative fuel source. It is use in cars, fuel cells, thermometers, alcoholic beverages.
Ethanol can be made from any crop or plant that contains a large amount of sugar or components that can be converted into sugar, such as starch or cellulose. As their names imply, sugar beets and sugar cane contain natural sugar. Crops such as com, wheat and barley contain starch that can be easily converted to sugar. Most trees and grasses are made of cellulose, which can also be converted into sugar, although not as easily as starch
Some of the country that use ethanol as an alternative fuel source are Brazil, USA and Australia. In the US 10% of all cars run on blends of ethanol and all petrol Brazil is a mixture of 250% ethanol to 75% petrol.
This is how ethanol is made
Step One: ... The Conversion Process
We have to break down carbohydrate sugars, such as the starch from com. Create it into "Mash". Grind or crush the feedstock (com, soybeans, wheat, etc. ...). Then dilute and add an enzyme (alpha amylase) to tum the mixture into a liquid. Once liquefied a second enzyme is added (glucoamylase) to convert the starch into sugar. (If the source is mainly sugar, i.e. ...rotten fruit, molasses, etc. ..., the conversion step can be skipped.
Step Two: ... Fermentation
Add yeast and make it into a beer (wine) type solution.
Step Three: ... Distillation
The beer (wine) type solution needs to be run through a still to extract the alcohol from the solution.
Step Four: ... Filtration
The ethanol now needs to be filtered to get rid of excess organic volatiles.
Step Five: ... Dehydration
The ethanol needs to be "dried". After the distillation process there will be a certain amount of water in the ethanol you have just created - this can be dried running the ethanol through Zeolite a readily available product for drying ethanol.
advantages of ethanol as a fuel source are it is a renewable, relatively safe fuel that can be used with few engine modifications. Its energy density is higher then some other alternative fuels, such as methanol, which means less volume is required to go the same distance. Another benefit of ethanol is that it can improve agricultural economies by providing farmers with stable markets for certain crops. Ethanol also increases national energy security because some use of foreign petroleum is averted. Ethanol also decreases carbon emissions.
Disadvantages of ethanol are it is costly to produce and use. At 1987 prices, it cost 2.5-3 .75 times as much as petrol. Another problem is that ethanol has a smaller energy density than petrol. It takes about 1.5 times more ethanol than petrol to travel the same distance. However, with new technologies and dedicated ethanol-engines, this is expected to drop to 1.25 times. Which in the long run cost more to run ethanol then petrol. An important consideration with ethanol is that it requires vast amounts of land to grow the crops needed to generate fuel. The process for conversion of crops to ethanol is relatively inefficient because of the large water content of the plant material. As . There is legitimate concern, especially in developing countries, that using land for ethanol production will compete directly with food production. This could lead to an increase in food prices.
Another problem is that ethanol burning may increase emission of certain types of pollutants. Like any combustion process, some of the ethanol fuel would come out the tailpipe unburned. This is not a major problem since ethanol emissions are relatively non-toxic. However, some of the ethanol will be only partially oxidized and emitted as acetylaldehyde, which reacts in air to eventually contribute to the formation of ozone.
Finally, ethanol production, like all processes, generates waste products that must be disposed. The waste product from ethanol production, called swill, can be used as a soil conditioner on land, but is extremely toxic to aquatic life.
So as you can see there are many more disadvantages than advantages when it comes t ethanol so at the end of the day we would have to come you with a better alternative fuel source.
With a new fuel source there must be politics involved. Politics the distribution and abundance of the product in this case ethanol. If ethanol when into full circulation it would replace petroleum. This would mean that the government would lose money and the government doesn't like to lose money. The money that the government makes on oil keeps the economy running and keeps money in there pockets.
In conclusion ethanol in an alternative fuel source but is more trouble then it is worth. Until we can find a better fuel source we should stick to petroleum fuel.