In recent years, a new round of enthusiasm in biomass and bioenergy has been initiated with the recognition that the global crude oil reserve is finite, and its depletion is occurring much faster than previously predicted. In addition, the environmental deterioration resulting from the over-consumption of petroleum-derived products, especially the transportation fuels, is threatening the sustainability of human society. Ethanol, both renewable and environmentally friendly, is believed to be one of the best alternatives, leading to a dramatic increase in its production capacity. Fig. 1 illustrates the increasing trend of ethanol production in the United States since 1980. As can be seen, a total production capacity of 4.89 billion gallons was achieved in 2006, representing a treble increase compared with that of 1.63 billion gallons in 2000. Other countries, such as China and India, are following this trend. The National Development and Reform Commission of the People's Republic of China initiated Chinese National Fuel Ethanol Program in 2002. Three large fuel ethanol plants with a total annual production capacity of 1.2 million tons were approved thereafter, and put into operation in 2005.