Scenario-based screening of agricultural residues and perennial energy grasses for hydrothermal co-production of xylooligosaccharides and fermentable sugars

Agricultural residues and perennial energy grasses are promising lignocellulosic resources; however, their suitability for hydrothermal biorefineries depends on conversion performance, hydrolysate quality, biomass supply, and economic context. Here, 12 feedstocks, including five agricultural residues and seven perennial energy grasses, were evaluated under a unified hydrothermal pretreatment condition of 190℃ for 10 min (severity factor, log R 0 =3.65) for the co-production of xylooligosaccharides (XOS) and fermentable sugars. The feedstocks differed markedly in feedstock composition, crystallinity, fractionation behavior, enzymatic digestibility, inhibitor formation, and annual dry matter supply intensity. On a dry-matter basis, XOS, glucose, and total inhibitor yields ranged from 2.16% to 16.99%, 8.42–33.96%, and 0.44–3.49%, respectively. Zea mays L. (corncob) exhibited the best process-level performance, with the highest XOS, glucose, and total sugar yields, owing to its favorable hemicellulose availability, low ash content, low native crystallinity, and efficient xylan solubilization. Saccharum officinarum L. (sugarcane bagasse) is favorable for glucose-oriented valorization, but it generates more inhibitors. In contrast, high-yielding perennial grasses, especially Miscanthus lutarioriparius L.Liu ex S.L.Chen & Renvoize ( M. lutarioriparius ) and Arundo donax L. ( A. donax ), showed lower conversion yields but a stronger areal supply potential. Multi-criteria scenario evaluation ranked corncob first under the quality-oriented co-production scenario, whereas M. lutarioriparius ranked first when biomass supply intensity was considered, followed by corncob and Saccharum spontaneum L. ( S. spontaneum ). Indicative economic analysis further suggested that XOS contributed the largest share of revenue, while feedstock rankings diverged between per-Mg and per-hectare assessments, with high-yielding perennial grasses ranking markedly higher on a per-hectare basis. These results provide a scenario-based framework for matching lignocellulosic feedstocks with various hydrothermal biorefinery objectives.