CHAPTER ONE 1.0 INTRODUCTION Ethanol fuel, ethyl alcohol (CH3CH2OH), is the same type of alcohol found in alcoholic beverages. It is an oxygenated fuel with a high octane value like that of petroleum fuels known to run combustion engines at higher compression ratios and thus provides superior performance (Wheals et al., 1999). The blending of ethanol into petroleum-based automobile fuels can significantly decrease petroleum use and decrease the release of greenhouse gas emissions. Furthermore, ethanol can be a safer alternative to the common additive, methyl tertiary butyl ether (MTBE), in gasoline. Methyl tertiary butyl ether is toxic and is a known contaminant in ground water. Thus, ethanol can be a substitute to mitigate the problems associated with the rising energy demands across the world as well as a way to reduce greenhouse gas emission to as high as 85% (Perlack et al., 2005). Ethanol may be produced either from petroleum products or from biomass substrate. Today, most of the ethanol produced comes from renewable resources (Bothast and Saha, 1997). Although, most of the ethanol currently produced from renewable resources come from sugarcane and starchy grains, significant efforts are being made to produce ethanol from lignocellulosic biomass (almost 50% of all biomass in the biosphere such as agricultural residues are lignocellulosic biomass). The technological advances in recent years are promising to produce ethanol at low cost from lignocellulosic biomass (Bothast and Saha, 1997). Bioethanol production from sugarcane and starch-rich feed stocks such as corn, potato, is considered a first generation process because it has already been developed (Joshi et al., 2011).