(402o) Pretreatment Strategies for Enhanced Fermentable Sugar Recovery from Composite Lignocellulosic Feedstocks

The sustainable production of biofuels from lignocellulosic biomass hinges on feedstock selection and the efficient conversion of complex polymers into fermentable sugars. Composite feedstock, such as blends of various lignocellulosic feedstocks, offers a consolidated approach to improving sugar yields while supporting sustainable waste management [1]. However, the inherent variability among biomass types necessitates effective pretreatment strategies to accommodate feedstock blending and maximize sugar recovery [2, 3]. This study comprehensively evaluates pretreatment strategies for composite feedstocks, focusing on their impact on fermentable sugar yields. Dilute acid pretreatment, combined with hydrothermal processing, has demonstrated significant efficacy in modifying the physicochemical properties of blended feedstocks. For instance, combining wastepaper /cardboard (≥35–60% cellulose and ≤1–20% lignin) with corn stover (≥30–45% cellulose and ≤10–25% lignin) with a ratio (20-30:70-80) resulted in over 85% total cellulosic sugar yields using hydrothermal pretreatment assisted by dilute sulfuric acid [4-6]. Additionally, utilizing a feedstock blend ratio of 20:80 (wastepaper/cardboard: corn stover) with an acid-assisted ionic liquid pretreatment significantly improves biomass deconstruction and lignin removal, along with high sugar recovery in the downstream process [7]. Furthermore, sequential pretreatment strategies, such as mechanical processing (e.g., ball milling) integrated with hydrothermal pretreatment, this treatment has been employed to efficiently fractionate diverse lignocellulosic substrate, due to its cost effectiveness and adaptable process conditions[8], also have shown exceptional performance, achieving over 90% of cellulosic sugar recoveries [2]. Additionally, biomass blending strategies based on total structural carbohydrates over 59% and low ash content (<5%) have been reported to be economically feasible by enhancing sugar yields and reducing processing costs [9]. This study consolidates current knowledge on compositional modification, enzymatic saccharification efficiency, and pretreatment optimization. Further research focused on optimizing feedstock blending ratios, developing robust inhibitor mitigation techniques, and advancing integrated biorefinery frameworks could facilitate the use of organic fractions from municipal solids waste, agricultural residues, and wood-based biomass, thereby diversifying feedstock supply to support the circular bioeconomy.

Keywords: Lignocellulosic biomass, Cellulosic sugars, Biomass blends, Biomass pretreatment

References

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