Assessing the Limits of Advanced Biofuel Supply on Transportation

Focus Area

Climate Change


Air Quality, Environmental Process







Research Idea Scope

Problem Statement
Advanced (2nd and 3rd generation) biofuels include a range of renewable liquid or gaseous fuels produced from non-food sources such as woody grasses, agricultural residues and organic waste. Processes include conventional anaerobic digestion, as well as advanced bioreactors and gasification and fermentation technologies. In addition to the mandates for advanced biofuel production established under President Bush, a new round of renewable fuel standards, California’s low carbon fuel standard and the possibility of greenhouse gas caps are making 2nd and 3rd generation biofuels an increasingly important part of the fuel pool. However, as with 1st generation biofuels, there may be practical limits to these fuels’ contribution to U.S. fuel supplies. These limits include the volume of resources likely to be available, competition with other end-uses (e.g., electricity generation, natural gas for stationary use), competition for arable land to produce biomass resources, production costs, limitations on blend percentage (e.g., vapor pressure limitations for ethanol in gasoline, cold-flow performance for some types of biodiesel), limitations on production incentives, and availability of vehicles that can use the fuel (e.g., flexible fuel vehicles that can use E-85). Options for increasing biofuel quantities include expanding the resource base that can be used, developing advanced production technologies and supplementing supplies with imports from foreign countries.
The contribution that advanced biofuels can make to the U.S. transportation fuel market shall be estimated. The maximum practical production potential for ethanol, biodiesel and other potential biofuels will be estimated taking into account the existing resource bases for each, the economics of competing uses, and a range of incentives. Long-term potential (20 years or more from now) for biofuels production and use will be estimated including consideration of additional resources, advanced technology production processes, the impact of global climate change on the resource base, and the potential for imports from foreign countries. A sensitivity analysis will be conducted of the factors affecting biofuels production. Technical limitations on the use of biofuels in vehicles shall be taken into account when estimating the total amount that could be used as fuel. This should include an assessment of whether production incentives can lead to future production that is self-sufficient.
Related Work
·      Perlack, R. et al., 2005. Biomass as Feedstock for Bioenergy and Bioproducts Industry: The Technical Feasibility of a Billion-Ton Annual Supply, Oak Ridge National Laboratory for U.S. Department of Agriculture and U.S. Department of Energy, April.
·      Early, J. and A. McKeown, 2009. Red, White and Green: Transforming U.S. Biofuels, Worldwatch Institute, Worldwatch Report 180, Washington, D.C., January.
·      Biomass Research and Development Board, 2008. National Biomass Action Plan, Oct. accessed Oct. 2009 at
·      Biomass Research and Development Board, 2009. Increasing Feedstock Production for Biofuels Economic Drivers, Environmental Implications, and the Role of Research, accessed Oct. 2009 at
Urgency/PriorityThe proposed research will contribute to the ongoing dialogue on renewable fuel strategies, policies, and investments by providing a consistent, objective context for evaluating competing claims by technology and project developers.

Urgency and Payoff

The desired project outcome is a final report with forecasts of potential advanced biofuel supplies by type.
EffectivenessThis research will refine our understanding of the feasibility of meeting renewable fuel goals and the potential of various advanced technologies to contribute to that effort.

Suggested By

RNS. Sponsoring Committee: A0020T, Special Task Force on Climate Change and Energy Source Info: Special Task Force on Climate Change and Energy January 2010 Workshop