How to reduce environmental burden caused by lignocellulosic waste: A solution from the pharmaceutical industry with green solvents

In order to reduce environmental burden caused by lignocellulosic waste, lignin from Eucommia ulmoides residue was extracted via alkali treatment and acid precipitation, yielding 61.58% purity. Degradation using [N4222]Im and [Ch]Im under atmospheric and microwave conditions was analyzed by elemental, UV, and FT-IR methods. Microwave treatment gave higher hydroxyl (340.54 mg KOH/g) and phenolic hydroxyl (0.32 mmol/g) contents than atmospheric degradation. Gas chromatography analysis showed aromatic compounds accounted for 75.64% of products, dominated by guaiacol and derivatives. This work supports high-value utilization of herbal residues, which is expected to protect our environment.