Techno-economic assessment of single-stream feedstock logistics supply chain for corn stover and grain

The state-of-technology for corn stover harvest is a multi-pass system that collects the stover after grain harvest. An alternative is a single-stream system where the grain and stover are harvested as a bulk material co-stored and preserved by anerobic fermentation, and finally, co-transported to a biorefinery. In the present work, four single-pass whole-plant bulk systems were compared with a conventional multi-pass bale system. The single-stream systems consisted of the harvest of corn grain and a portion of the stover fraction. Four machine configurations were simulated. This work predicted that a multi-pass bale system would result in a material cost of 111.80 $2021 Mg-1 stover DM delivered to the biorefinery gate. Alternatively, the lowest cost single-stream system was the self-propelled forage harvester (SPFH) configured with the whole-plant header, which delivered feedstock for 74.76 $2021 Mg stover DM-1. In addition to machine configuration, a sensitivity analysis was performed to understand important drivers of feedstock cost. These analyses revealed that feedstock cost increased with moisture content, fertilizer price, and biorefinery size, and decreased with harvest season length, crop yield, and grower participation. This work demonstrated that single-stream systems could reduce corn stover feedstock costs in comparison with state-of-technology systems. (c) 2022 The Authors. Biofuels, Bioproducts and Biorefining published by Society of Industrial Chemistry and John Wiley & Sons Ltd.