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 N4222Im and ChIm 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.
Yu et al. (Sun,) studied this question.