The “Stover Availability versus Supply” Puzzle and Contracting Options for Cellulosic Biomass

THE EXISTING US Renewable Fuel Standard (RFS) makes commercial-scale cellulosic ethanol a priority, calling for 16 billion gallons of cellulosic biofuel production by 2022, sourced from grasses, trees, agricultural residues, and municipal waste. The US Department of Energy “US Billion-Ton Update” study (Downing et al. 2011) suggests that to meet the mandates in the RFS, approximately 66 million tons of corn stover may be needed annually. This equates to nearly 50 percent of the total annual stover produced by Illinois, Iowa, Minnesota, and Nebraska (Sesmero et al. 2015)