Green valorization of lignocellulosic residues: advances in pretreatment and fractionation into cellulose and lignin for nanoparticles production

Abstract The sustainable valorization of lignocellulosic biomass into high‐value nanomaterials is gaining momentum as an alternative to synthetic nanoparticles, driven by their biodegradability, biocompatibility, and broad applicability. Nanocellulose and nanolignin, derived from cellulose and lignin extracted from agricultural and forestry residues, offer potential in packaging, medicine, energy, and advanced materials. However, the intrinsic recalcitrance of lignocellulosic feedstocks necessitates efficient pre‐treatment strategies that are both environmentally responsible and industrially viable. This review explores recent advances in eco‐friendly methods for the extraction of cellulose and lignin, with particular emphasis on ionic liquids (ILs), deep eutectic solvents (DESs), and catalytic systems. ILs demonstrate high dissolution and recycling potential, DESs provide tunability and low toxicity, while catalysts—such as zeolites and metal oxides—enhance selectivity and lignin‐first valorization. The integration of complementary techniques, including microwave‐ and ultrasound‐assisted extractions, further improve efficiency. To evaluate the sustainability of these emerging processes, the Path2Green framework was applied. Results show that, despite frequent claims of ‘green’ performance, most IL‐ and DES‐based systems achieved only neutral or slightly negative sustainability scores, largely due to synthetic origins, energy demands, and limited recycling. Catalytic flow‐through processes achieved the most favorable profiles, highlighting the importance of solvent choice, closed‐loop design, and scalability. Overall, progress demonstrates that no universal solution exists; instead, feedstock‐specific, integrated approaches are essential. Future directions should prioritize bio‐based solvents, closed‐loop recycling, renewable energy integration, and standardized reporting to bridge the gap between laboratory innovation and industrial application. © 2026 Society of Chemical Industry (SCI).