| 摘要 |
<p>A method for preparing high-purity levoglucosan from pyrolysis oil derived from cellulose, comprising: mixing pyrolysis oil with water and a basic metal salt in amount sufficient to elevate pH values to a range of from about 12 to about 12.5, and adding an amount of the salt in excess of the amount needed to obtain the pH range until colored materials of impurities from the oil are removed and the slurry is formed; drying the slurry azeotropically with methyl isobutyl ketone solvent to form a residue; and further drying the residue by evaporation; reducing the residue into a powder; continuously extracting the powder residue with ethyl acetate to provide a levoglucosan-rich extract; and concentrating the extract by removing ethyl acetate to provide crystalline levoglucosan.</p> |
