Corn cobs represent a major source of underutilized agricultural leftovers with significant lignocellulosic content that can be fractionated using the acetosolv process. The acetosolv process was simulated in Aspen Plus® to evaluate its techno-economic feasibility, incorporating experimental data to ensure mass and energy balance accuracy. The process includes hydrolytic reaction using an acid catalyst at 110°C and atmospheric pressure, subsequent washing and precipitation of cellulose, hemicellulose and lignin fractions, and solvent (acetic acid) recovery. A detailed reaction model was implemented using stoichiometric conversions, with lignin precipitation assumed to be complete. The initial TEA estimates a capital expenditure (CAPEX) of $11 million and an operating expenditure (OPEX) of $23.43 million per year, with raw material costs contributing approximately 53%. The solvent recovery section achieves a 98% recovery rate; however, acetic acid (AcOH) and ethanol (EtOH) presence leads to ethyl acetate (EthyAc) formation via sulfuric acid-catalyzed esterification that can lead to the formation of azeotropic mixtures and associated separation challenges. Detailed analysis of such scenarios shows that despite these challenges, cost estimates align with reported organosolv processes involving other biomass types. Based on the values of various products demonstrated to date (crude cellulose, hemicellulose, vanillin, p-hydroxybenzaldehyde and resins) from corn cobs, our analysis demonstrates potential for economic viability of a corn cob-based biorefinery. Complementary life cycle assessment (LCA) of the acetosolv process will also be presented, focusing on greenhouse gas emissions, energy consumption, and solvent recovery efficiency. These assessments will inform process optimization and scale-up strategies, particularly heat integration to reduce OPEX, and facilitate a quantitative estimation of the carbon credits made possible by corn cob utilization.
