Bioethanol (ethyl alcohol, fuel ethanol) is the most-used liquid biofuel in the world. It is obtained from energy-rich crops, such as sugarcane and corn. Ethanol can be directly employed as a sole fuel in vehicles or as gasoline oxygenate increasing its oxygen content and allowing a better hydrocarbon oxidation that reduces the amount of aromatic compounds and carbon monoxide released into the atmo­sphere. For this reason, fuel grade ethanol (FGE) is the market with the most rapid growth rate in America and Europe.

The fuel ethanol can be obtained from lignocellulosic biomass as well, but its production is much more complex. Nowadays, great efforts are being made to diminish the production costs of lignocellulosic ethanol. It is expected that the evolution of biomass conversion technologies will allow the massive oxygenation of gasoline with fuel ethanol and make possible the substitution of a significant portion of fossil fuels considering the huge availability of lignocellulosic world­wide (Bull, 1994).