Biomass-based fuels present a tremendous opportunity to transition toward a more sustainable mix of renewable energy. This was a key theme of a workshop on alternative fuels hosted by the U.S. Department of Energy in Macon, Ga. The workshop examined the sustainability of feedstocks like soybean oil, which can be used to make biodiesel or alternative jet fuel.

Wally Tyner, a professor of agricultural economics at Purdue University, presented his research team’s latest findings regarding the greenhouse gas (GHG) emissions of producing biodiesel from soybeans. Those findings confirm that soybean oil offers very good carbon reduction when used to displace fossil fuel. Tyner is supported by the James & Louis Ackerman endowment.

Tyner said, “While these results are preliminary, our most recent analysis suggests that induced land use change emissions could be as much as 70% lower than those adopted by the California Air Resources Board (CARB) as recently as last year.”

Tyner and the experts at Purdue are using the latest version of the Global Trade Analysis Project model to build upon the previous work done for CARB. Significant change resulted from updating the underlying data from 2004 to 2011. A lot changed in agriculture and biofuels between 2004 and 2011, Tyner said. Biofuel policies expanded greatly during that period. The other major factor reflects increased total outputs per farm area through yield improvements and practices such as double cropping.

“We now have much more data,” Tyner said. “We are better equipped to quantify potential land use change by observing what has actually happened in the real world and calibrating our models to make better predictions on that basis.”

Don Scott, National Biodiesel Board director of sustainability, added, “Consensus is rarely achieved when it comes to the theory of indirect land use change, but one thing is clear: As the accuracy and reliability of modeling improves, we observe a steady decline in the estimates of predicted land use change. This reaffirms that biodiesel reduces GHG emissions by at least 50% and suggests that the real benefit is greater than 80%.”

Biodiesel has long been championed by DOE and the U.S. Department of Agriculture for reducing carbon emissions by nearly 80% compared to petroleum. The Environmental Protection Agency and CARB have gone beyond traditional life-cycle analysis to quantify the potential expansion of agriculture that might be induced by major biofuel policies.

Both regulatory agencies have conducted economic modeling to quantify this indirect effect. While each confirms that biodiesel reduces emissions by at least 50% even after adding potential indirect emissions, interest remains in studying these effects with more certainty, Scott said.

“Today’s announcement adds confidence in the GHG benefits of biodiesel while improving our understanding of how agriculture can respond to growing demand,” he said.

Made from an increasingly diverse mix of resources such as soybean oil, recycled cooking oil and animal fats, biodiesel is a renewable, clean-burning diesel replacement that can be used in existing diesel engines without modification. It is the nation’s first domestically produced and commercially available advanced biofuel.