METHOD FOR SEPARATING METHANOL-MEDIATED HEMICELLULOSE ALKALINE SOLUTION AND METHOD FOR SEPARATING ETHANOL-MEDIATED HEMICELLULOSE ALKALINE SOLUTION

摘要

Disclosed are a method for separating a methanol-mediated hemicellulose alkaline solution and a method for separating an ethanol-mediated hemicellulose alkaline solution, wherein methanol/ethanol is added to an alkaline solution with dissolved hemicellulose, and is fully and uniformly mixed; the effect of the hydration layer formed between the hemicellulose and the alkaline solution is destroyed through the hydrophobic effect mediated by the methanol/ethanol, such that the hemicellulose is precipitated from the solution system; and a hemicellulose precipitate and the alkaline methanol/ethanol solution are obtained through sedimentation, centrifugation or filtration separation. By utilizing the promotion effect of alkaline conditions on the evaporation and gasification separation of methanol/ethanol and water, the methanol/ethanol and the alkaline solution are separated by using reduced pressure distillation (rectification) or a gasification membrane, and the prepared alkaline solution and the methanol/ethanol are reused for dissolving the hemicellulose and separation. By means of the complete reuse of the strong alkaline solution and methanol/ethanol of the method, the efficient, clean and economical production of alkali dissolution and separation of hemicellulose is achieved, and the separation and recovery efficiency of alkali-dissolved hemicellulose exceeds 99%.