Assessing the Limits of Biofuel Supply for Transportation

Focus Area



Air Quality







Research Idea Scope

TERI Administrator Note (Feb 2009) – This idea has been addressed via Biofuels in the U.S. Transportation Sector; US Energy Information Administration, 2007

The contribution that biofuels can make to the U.S. transportation fuel market shall be estimated. The maximum practical production potential for ethanol and biodiesel and other potential biofuels shall 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 shall be estimated including consideration of additional resources, advanced technology production processes, the impact global climate change will have on the resource base, and the potential for imports from foreign countries. A sensitivity analysis shall 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 shall include an assessment of whether production incentives can lead to future production that is self-sufficient.

Urgency and Payoff

Biofuels are becoming more popular for reasons that include mandates for oxygen content in gasoline, domestic energy security, compatibility with existing vehicles and fuels, favorable emission characteristics, and low net greenhouse gas production. However, there may be practical limits to the contribution that biofuels can make to fuel supplies. These limits include the number of biomass resources available, competition with other uses of biomass, 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 E85). Options for increasing biofuel quantities include expanding the resource base that can be used, developing advanced production technologies (i.e., cellulosic ethanol production), and imports from foreign countries. Global climate change may affect future biofuels production because of shifts in arable land. In addition, little is known about the stability of biomass feedstock production.

Suggested By

Transportation Research Board 2002 Environmental Research Needs Conference Notes

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