Biofuels in the US - Challenges and Opportunities

Biofuels are of rapidly growing interest for reasons of energy security, diversity, and sustainability - as well as for greenhouse gas mitigation. In recent years, the U.S. has enacted regulations - and adopted aggressive goals - to encourage increased usage of biofuels. Individual States (especially California) have taken even stronger positions with respect to biofuels. Initial efforts have focused mainly on ethanol, produced via fermentation of sugars from grains (especially corn). Today's R&D focus is on "2nd Generation Biofuels" that are produced from a variety of biomass feedstocks utilizing a wide range of conversion technologies. This paper summarizes policy and regulatory drivers for biofuels in the U.S., describes usage trends and projections, and highlights major R&D efforts to promote development and commercialization of 2nd Generation Biofuels. R&D is being conducted in many areas, including biomass resource assessment, development of new biomass feedstocks, improved conversion technologies, and integration of systems. Other important considerations include fuel quality and specifications, as well as requirements for blending, distribution, and storage. Considerable R&D, policy, and regulatory efforts are also focused on the energy and environmental consequences of biofuels. This includes not only direct emissions associated with vehicular uses, but also the fuels' life-cycle impacts with respect to total energy usage, greenhouse gas emissions, and multi-media effects. Due to the wide diversity of biomass feedstocks, conversion technologies, and systems integration approaches, the life-cycle impacts of biofuels can vary widely. (c) 2008 Elsevier Ltd. All rights reserved.