Fractional pretreatment of lignocellulose by alkaline hydrogen peroxide: Characterization of its major components

The biorefinery process for lignocellulose conversion generally requires fractionation of its three major components including cellulose, hemicellulose, and lignin. The present work demonstrates that the alkaline hydrogen peroxide (AHP) method for fractionating lignocelluloses, such as corncob, is advantageous due to its modest reaction conditions, low alkaline usage, and effective fractionation of three components. The removal ratio of lignin and hemicellulose after 6 h treatment reached 75.4% and 38.7%, respectively, leaving the recovery ratio of cellulose in the AHP residues at 81.3%. After 24h enzymatic hydrolysis of the AHP residues, we found that the degree of cellulose conversion was approximately 80%. Through ethanol precipitation and desalination, 89% of dissolved hemicellulose was recovered as white solids, whereas 77.5% of soluble lignin was obtained as brown solids. The isolated three components were further characterized. The major pyrolysis teinperature of the AHP residues increased. And the recovered lignin revealed an increase in carboxylic acid content and a decrease in phenolic hydroxyl content by oxidation of H2O2. (C) 2014 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.