The purpose of this study is to investigate a new process of chemical production from agricultural residues. The studied system reduces the environmental impacts and power requirements of current chemical production methods. The feedstocks, corn stover and swine manure, are utilized by a three-step biological and physical conversion process to produce value-added chemicals lactic acid and chitin. Anerobic co-digestion was applied on the feedstocks to produce biogas and generate carbohydrate-rich solid digestate. The solid digestate was then processed by a mechano-biocatalytic one-pot hydrolysis to release mono-sugars.Rhizopus Oryzae, a fungus, was used to convert mono-sugars into lactic acid and chitin. Under the steady state, anaerobic co-digestion produced 249±71 mL biogas/g volatile solids loading/day with a methane content of 62% (v/v). The mechano-biocatalytic process produced hydrolysate with high titers of glucose, xylose and acetic acid (32.90, 21.35, 4.06 g/L, respectively). The liquid hydrolysate was then fermented by R. oryzae to produce lactic acid (14.23 g/L) and mixed biomass (119 g dry matter) with a chitin content of 18% (w/w). A mass and energy balance on a farm-based biorefinery concluded that 199 m3 of biogas, 22 kg of lactic acid and 34 kg chitin per day can be produced by processing 1,000 kg dry feedstock per day. The energy balance showed that a positive net energy output of 2,200 MJ/1,000 kg dry feedstock was achieved by proposed process. Therefore, the studied system not only addressed the environmental challenges of agricultural residues handling and disposal but also produces value-added chemicals to generate revenues from the residues.
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