Polyethylene glycol lignin solvent and application of polyethylene glycol lignin solventin lignin separation and extraction

The invention relates to a polyethylene glycol lignin solvent and application of the polyethylene glycol lignin solvent in lignin separation and extraction. The lignin solvent comprises 40% by weight of water and 60% by weight of polyethylene glycol. The lignin solvent has excellent performances of being green and environmental-friendly and free of corrosivity. Moreover, lignin can be separated and extracted from straw stalks containing lignin at normal temperature by using the lignin solvent without a heating device or high-pressure resisting equipment, and the solvent can be recovered and recycled if lignin is extracted. Therefore, by using the lignin solvent to separate and extract lignin from straw stalks, raw materials and energy sources can be saved, the investment is reduced, the cost is low, the practicality is strong, and industrial promotion is easily realized.