10/07/2010
Could Biofuels Replace a Large Fraction of the U.S. Petroleum Demand?
All current food provisioning services continue to be generated by the cropland now in use while maintaining soil fertility and simultaneously achieving large GHG reductions.
The Science
Sustainability of large-scale biofuel domestic production is a serious concern. A new model has been developed at the DOE Great Lakes BioEnergy Research Center to assess the potential impact of existing and emerging technologies for the production of biofuels and animal feed. The model assumes that all land used for human food, forests, rangeland, and most other uses will not be affected by the production of bioenergy and animal feed. The only land considered for these technologies is currently allocated to animal feed and corn ethanol. The technologies considered in this study include separating and concentrating leaf protein, pretreating forage, and double cropping where possible. These results outlined in a recent article in Environmental Science & Technology indicate the potential for annual production of about 100 billion gallons of ethanol with no impact on domestic food production or indirect land use change, while significantly reducing U.S. greenhouse gas emissions, increasing soil fertility, and promoting biodiversity.
Summary
Researchers explore the possibility of three land-efficient technologies for producing food (actually animal feed), including leaf protein concentrates, pretreated forages, and double crops to increase the total amount of plant biomass available for biofuels. Using less than 30% of total U.S. cropland, pasture, and range, 400 billion liters of ethanol can be produced annually without decreasing domestic food production or agricultural exports. This approach also reduces U.S. greenhouse gas emissions by 670 Tg CO2-equivalent per year, or over 10% of total U.S. annual emissions, while increasing soil fertility and promoting biodiversity. Thus, a large fraction of U.S. petroleum consumption can be replaced without indirect land use change.
References
Dale, B., B. Bals, S. Kim, and P. Eranki. 2010. “Biofuels Done Right: Land Efficient Animal Feeds Enable Large Environmental and Energy Benefits,” Environmental Science Technology 44(22), 8385–89. DOI:10.1021/es101864b.