ABSTRACT
Introduction At the present time, the United States is almost totally dependent upon petroleum for liquid energy. One report stated that 71.5% of U.S. energy comes from oil and natural gas, whereas only 2% comes from biomass. Currently, the United States uses ~19.76 million bbl (1 bbl = 42 gal; 42 gal = 159 L) of petroleum/d (0.83 billion gal/d), 25.5% of total world consumption. In 2002, 58% of the petroleum was imported. For agriculturally produced renewable fuels, such as biodiesel, to make a significant contribution to this mammoth energy consumption will require every foreseeable agriculturally produced energy source that can be developed. This chapter reviews the status and contribution of only one of these fuels, i.e., biodiesel from vegetable oils and animal fats. Others, such as ethanol, are important components of the biomass complex.
