γ-Valerolactone-based processing of Eucalyptus globulus wood for integrated fractionation and platform chemicals production

Eucalyptus globulus wood was processed in a microwave-assisted system in media containing γ-valerolactone, water, and sulfuric acid, with or without NaCl (to promote phase separation). Under optimized conditions, the process enabled extensive hemicellulose solubilization (up to 90.6 %) and yielded solids with high cellulose content (up to 91.4 %), indicative of extensive delignification (up to 88 %). Subsequent acid-catalyzed processing of the saline aqueous phases mixed with γ-valerolactone, allowed the conversion of hemicellulose-derived saccharides into furfural at near 60% molar yield. Cellulose-rich solids exhibited high susceptibility to enzymatic hydrolysis, and the lignin recovered from the organic phase showed favorable structural features for further valorization. The addition of NaCl in aqueous/ γ-valerolactone systems improved partitioning, while γ-valerolactone played a dual role by enhancing biomass fractionation and furfural yields. Overall, the results highlight the potential of γ-valerolactone-based biphasic systems under microwave irradiation for the selective deconstruction of biomass and improved platform chemicals recovery.