One-step catalytic liquefaction of bamboo sawdust with in situ hydrogen from formic acid for enhanced bio-oil yield and quality

Abstract This study systematically investigated the catalytic hydroliquefaction of bamboo sawdust using formic acid as an in-situ hydrogen donor in water-alcohol co-solvent systems. The synergistic effects of reaction medium (e.g., water-ethanol, water-isopropanol) and catalysts (Ru/C and FHUDS-2) on product distribution and bio-oil properties were evaluated. Results showed that the combination of formic acid and FHUDS-2 in water-isopropanol achieved the highest bio-oil yield of 62.38 wt.% and near-complete biomass conversion (> 99 wt.%), significantly outperforming Ru/C-assisted processes. Furthermore, the addition of catalysts and formic acid effectively reduced the average molecular weight of bio-oil and enhanced its fuel quality by suppressing repolymerization and promoting hydrodeoxygenation. The proposed one-step liquefaction strategy demonstrates high potential for efficient valorization of lignocellulosic biomass into high-quality bio-oil.