Winter Rye: Energy Potential of Cover Crops with Anaerobic Digestion and Uses for Solid Digestate

Anaerobic digestion is a process that harnesses the metabolic potential of bacteria to produce methane from biomass, like crop residues and manure. This methane can be compressed further to produce heat, electricity, or fuel. Biogas production via anaerobic digestion can be used as an alternative for fossil fuels and has the potential to significantly reduce greenhouse gas (GHG) emissions. Additionally, diverting crop residue to anaerobic digesters (ADs) would harness the methane for power rather than emitting methane during decomposition, a GHG with roughly 23-34 times more heat trapping potential than carbon dioxide. A barrier to adopting ADs on farms is high upfront costs for equipment and construction. In Pennsylvania, the average dairy farm size is significantly smaller than most farms with anaerobic digesters. As a consequence, many farmers do not have enough animal waste to consistently produce enough methane to make the investment of an AD realistic. Including crop residues as well as animal waste in ADs could make the investment more economically viable. Using data from potential winter rye yields on corn and soy fields in PA, the total biogas and energy potential of winter rye was calculated. Winter rye can potentially to produce up to 3.05 trillion BTU annually accounting for 100% of the addressable market [6,7]. Additionally, the solid digestate from the AD can be used as a fertilizer due to the high ammonium content. As Pennsylvania is agriculturally bountiful, more ADs installed on farms have the potential to significantly reduce methane emissions from unprocessed decomposing waste while producing renewable energy.

Monday Poster Session
Amanda Liebhardt
Related Conference Themes
Electricity Generation