Method for purifying lignin

Abstract

The present document discloses a method for purifying lignin. The method comprises steps of solvent dissolution, ultrasonic vibration, centrifugal filtration, stirring in water at a constant temperature, and membrane filtration and drying. In the present application, lignin extracted from a plant fiber raw material using an organic solvent is added to a specific solvent, and is purified by sequentially performing the steps of ultrasonic vibration, centrifugal filtration, stirring in water at a constant temperature, and membrane filtration and drying. Any of the steps cannot be omitted and the sequence thereof cannot be reversed. The steps are efficiently coordinated to achieve a synergistic effect, so as to remove impurities in lignin, and significantly improve the purity of the lignin while maintaining a high purification yield. The invention has broad application prospects and high market value.

Dependencies are inferred from the claim text.