The U.S. Department of Energy (DOE) hosted an alternative fuels workshop in Macon, Georgia this week that reviewed the sustainability of feedstocks, such as soybean oil, used when producing biodiesel or biojet fuel. During the event, Purdue University Professor Wally Tyner presented the latest findings from a team research project (funded by the James and Louis Ackerman endowment) focused on the greenhouse gas emissions (GHGs) of producing biodiesel from soybeans. His findings found that soybean oil offers very good carbon reduction when used to displace fossil fuel.
“While these results are preliminary our most recent analysis suggests that induced land use change emissions could be as much as 70 percent lower than those adopted by the California Air Resources Board (CARB) as recently as last year,” Tyner said.
The research team utilized the most recent version of the Global Trade Analysis Project (GTAP) model to build upon previous work done for the California Air Resources Board (CARB). The study found significant changes in the results using data from 2004 to 2011. Why the changes? Tyner noted that a lot has changed in agriculture during this timeframe while biofuel policy expanded. Other factors included increased total outputs per farm area through yield improvements and practices such as double cropping.
“We now have much more data,” said Tyner. “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’s director of sustainability said, “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 percent and suggests that the real benefit is greater than 80 percent.”
According to NBB, both the EPA and CARB have gone beyond traditional lifecycle analysis to quantify the potential expansion of ag that might be induced by major biofuel policies. Scott noted that both regulatory agencies have conducted economic modeling to quantify this indirect effect. While each confirms that biodiesel reduces emissions by at least 50 percent even after adding potential indirect emissions, interest remains in studying these effects with more certainty, Scott said, who added, “Today’s announcement adds confidence in the GHG benefits of biodiesel, while improving our understanding of how agriculture can respond to growing demand.“
