Bioethanol a renewable fuel produced from agricultural raw materials, such as cereals. Since ancient times ethanol was obtained by anaerobic fermentation of a solution containing sugars with yeast, for subsequent distillation.
Bioethanol is either directly blended with gasoline and used in engines or used as a component in gasoline production (ETBE) for gasoline oxygenation.
When is directly blended with gasolines, the proportion between both fuels is usually indicated by the percentage of ethanol preceded by a capital E. In this way, E10 blend is composed of 10% ethanol and 90% gasoline, and E85 is obtained by mixing 85% ethanol and 15% gasoline.
The proportions of ethanol in the mixture varies in each country. The minimum ratio used is E5. E10 has currently become the fuel of reference for the EU. E85, known as superethanol, has many advantages and is used in the vehicles specially designed or adapted to this fuel.