SLEEPS - Storage, Logistics and Economics of Ethanol Production from Stover

SLEEPS is a user friendly, Microsoft Excel-based model that allows users choose from various wet and dry storage configurations to determine their impact on feedstock delivery, ethanol yield and ethanol production cost. This two-part, dry and wet storage comparative process-cost model covers corn stover logistics chain from harvest to delivery at the biorefinery and production of ethanol. The first part of the model focuses on upstream processes and among other outputs, estimates dry matter loss and the minimum feedstock delivery cost required to break even. The second part focuses on downstream ethanol production and estimates ethanol yield, ethanol production cost and minimum ethanol selling price (MESP) among others. SLEEPS provide a comparative tool in storage analysis; comparing wet and dry storage outcomes on biofuel production from corn stover, and the economic implication of the storage method chosen for the feedstock preservation. Feedstock delivery cost factors in logistics cost from harvest, collection and storage to transportation to biorefinery. It also factors in biomass losses across the supply chain. The ethanol production factors in changes that occur during storage that affects feedstock composition and conversion. The ethanol yield is predicted using the presence or absent of organic acid during storage and after pretreatment. See Video for desciption: https://www.youtube.com/watch?v=-x8Mv5Mc3m4