Book excerpt: A review is undertaken of several approaches to producing alternative transportation fuels using feedstocks that are under the control of the United States. The objective of the review is to provide the non-specialist reader with a general understanding of the several approaches, how they com pare regarding process energy efficiency, their individual abilities to provide f or national transportation fuel needs, and their associated capital costs. It is noted that, in principle, vehicle missions determine fuel and propulsion plant requirements rather than the other way around. In reality, of course, there is a tradeoff among desired mission capabilities and fuel and propulsion plant technologies.