Techno‐economic assessment of biomass bales storage systems for a large‐scale biorefinery

Abstract

AbstractStorage of agricultural residues and energy crops is essential for preserving and maintaining its economic value, and year‐round continuous delivery to a biorefinery. In this study, a dynamic cost model was developed for three storage methods (Indoor, Outdoor‐tarped, and Outdoor‐open) with two biomass bale types (rectangular and round) to estimate the storage cost of corn stover and switchgrass. The effects of storage time and multiple‐use of a storage facility on the storage cost were also evaluated to develop effective storage strategies. The cost of bale storage systems comprised of capital expenses for infrastructures, bale handling, dry matter loss (DML) and quality loss costs. Among storage methods, the outdoor‐tarped storage with rectangular bales was the least expensive options for corn stover ($14.6 dry Mg−1) and switchgrass ($16 dry Mg−1). Indoor storage of round bales was costly due to the large storage footprint requirement and high infrastructure investment. However, the indoor storage cost could be reduced, if the storage facility could be used more than once a year. The sensitivity analysis study illustrated that the DML, biomass cost, loading/unloading time and bale density were the most sensitive parameters influencing the storage cost. An example storage strategy developed for a typical biorefinery could reduce the average annual storage cost (up to $10 dry Mg−1) along with an annual cost saving ranging from 10 to 100% compared with any single storage option. © 2017 Society of Chemical Industry and John Wiley & Sons, Ltd.