Mohammad J. Taherzadeh and Keikhosro Karimi

3.1 Introduction

Ethanol (C2H5OH) is a clear, colorless, flammable chemical. It has been produced and used as an alcoholic beverage for several thousand years. Ethanol also has several industrial applications (e. g., in detergents, toi­letries, coatings, and pharmaceuticals) and has been used as trans­portation fuel for more than a century. Nicholas Otto used ethanol in the internal combustion engine invented in 1897 [1]. However, ethanol did not have a major impact in the fuel market until the 1970s, when two oil crises occurred in 1973 and 1979. Since the 1980s, ethanol has been a major actor in the fuel market as an alternative fuel as well as an oxy­genated compound for gasoline. Ethanol can be produced synthetically from oil and natural gas, or biologically from sugar, starch, and ligno — cellulosic materials. The biologically produced ethanol is sometimes called fermentative ethanol or bioethanol. Application of bioethanol as fuel has no or very limited net emission of CO2 [2] and is able to fulfill the Kyoto Climate Change Protocol (1997) to decrease the net emission of CO2 [3]. In this chapter, the global market and the production of bioethanol are briefly reviewed.