Method for pretreating straw waste by using choline hydroxide eutectic solvent

The invention belongs to the technical field of biomass recycling, and discloses a method for pretreating straw waste by using a choline hydroxide deep-eutectic solvent, which comprises the following steps: mixing straw with a deep-eutectic solvent aqueous solution, stirring at 70-100 DEG C, and filtering to obtain filtrate I and cellulose; washing the cellulose to obtain filtrate II; mixing the filtrate I and the filtrate II, adjusting the pH value to 2, filtering and washing to obtain filtrate III and water-insoluble LCC; adding absolute ethyl alcohol into the filtrate III, standing, filtering, and washing to obtain filtrate IV and water-soluble LCC; and carrying out reduced pressure distillation on the obtained filtrate IV to obtain the regenerated eutectic solvent. According to the method, the problems that the existing cellulose is relatively low in yield and not high enough in separation purity are solved, the cellulose with the yield being about 100%, the purity being greater than 80% and the polymeriz