Method for preparing microcrystalline cellulose and cellulose fuel ethanol by separating furfural residue

The invention relates to a method for preparing microcrystalline cellulose and fiber ethanol by separating furfural residues, which comprises the following steps: (1) ethanol is taken as a solvent, a circulating ultrasonic extraction method is adopted to extract, and lignin is separated from an extraction liquid; (2) extraction residues adopt complex enzyme of endoglucanase and beta-glucosaccharase for enzyme-catalyzed hydrolysis, and a hydrolysate is fermented to prepare the ethanol; and (3) hydrolysis residues are subjected to acid-catalyzed hydrolysis to separate the microcrystalline cellulose. The extraction method has the advantages that the extraction method is green and environment-friendly, the enzyme-catalyzed hydrolysis has mild conditions, the side effect is small, the acid concentration needed by acid hydrolysis is low, the action time is short, and the yield of each step is high; and the method has smart process combination, can greatly reduce the production cost for the microcrystalline cellulose and the fiber ethanol by utilizing a special structure of furfural waste residues, and has double benefits of economization and environmental protection.