A techno‐economic analysis of the corn stover feedstock supply system for cellulosic biorefineries

The primary feedstock choice for most first-generation commercial cellulosic biorefineries in the Midwest is corn stover. Their rated capacities are between 76 and 114 million liters per year (MLPY). For uninterrupted operation of these plants, a year-round supply of corn stover needs to be secured, requiring a robust, efficient, and cost-effective feedstock supply system. Thus, the main objective of this work is to stochastically analyze the techno-economics of corn stover supply system for a 114 MLPY cellulosic biorefinery in the Midwest using production-scale experimental field data collected in Iowa. This study analyzes the resources requirements (equipment, labor, fuel, and consumables) and costs of different components of the supply chain that include harvesting (windrowing and baling), in-field bale collection and stacking at the field-edge, handling and transportation of bales from the field-edge to the distributed storage facilities and then to the biorefinery plant, storage, and finally the audit of nutrients removed during stover collection from the field. Additionally, this study identifies and ranks different supply chain parameters based on their relative influence on the overall resources and costs requirements. A 114 MLPY cellulosic biorefinery annually requires around 0.95 million corn stover bales supply, 250 000 hours equivalent of labor and 4.3 million L of diesel fuel. The average cost of biorefinery gate delivered corn stover is estimated to be 121.9 $-std. t−1. This cost is identified to be the most sensitive to bale density followed by harvest rate, bale length, baler field efficiency, and annual harvest days. © 2016 Society of Chemical Industry and John Wiley & Sons, Ltd