Introduction of ethanol, a natural biofuel.

From time immemorial man has sought to improve transportation. He initially sought to develop maximum for optimum performance. But often these advances have been despising the environment. Today, in industrialized countries, the automobile is one of the means of transport most used. Plans are underway to make them less polluting. Many solutions have been proposed, one of which is biofuel. There are a large number divided into two groups:

• The best known oilseed biofuels (oil) is rapeseed oil. They are obtained from: plant, animal fats. They can be used to replace diesel fuel in diesel engines. It is interesting to note that the first prototype diesel engine Rudolf Diesel worked with vegetable oils.

• ethyl Biofuels (alcohols) The Ethyl tertiary butyl ether (ETBE) obtained by reaction between ethanol isobutene is used as an additive in the amount of 5% in gasoline to replace lead. Methanol (or wood alcohol) can be used to replace gasoline in some engines or as an additive in the fuel. Butanol: it is made from oats, beet and sugar cane, and can servire additive to gasoline or diesel fuel Ethanol: currently the most widely used, it can replace gasoline. . (Unleaded Unleaded 95 and 98 There are different types:

E100-pure ethanol.
E85-85% ethanol and 15% gasoline.
E70-70% ethanol and 30% gasoline.

In France since 1 January 2007, the E85 is freely available in some stations. In other European countries such as Germany and Sweden ethanol is freely available for many years. Some major automakers are against the use of biofuels because they believe they can damage the engine. Other as Saab and Volvo encourage their use.

For our TPE we selected a biofuel: ethanol-type E100, and we will focus on its production and its effects in a four-stroke engine that uses a traditional fuel, the engine of a Volkswagen bug.

I The production of ethanol and its identification.

• How to obtain ethanol and identify Ethanol is the primary alcohol found in wine and a variety of alcoholic beverages, it is made ​​of two main steps: fermentation and hydrodistilation.

A) Fermentation

There are several ways to produce ethanol. They have one thing in common, a plant product is the lowest in the reaction that produces ethanol. The plant product in question must produce sugar. (Sugar can be either glucose as sucrose) should put the sugar in water (There must be at moins80% by weight of water) and adding the yeast (baker's yeast) in the yeast will be that bacteria will degrade for the sugar alcohol. This is called glycolysis. (This is a series of reactions catalyzed by enzymes which degrade a glucose molecule, (6 carbon atoms), into two molecules of pyruvate, (3 carbon atoms, this will allow the development of ethanol)

Source: www.meteoenfrance.com