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

•We designed a novel fractionation method for components of lignocellulose in corncob.•It has advantages: modest condition, low usage of alkaline, non-toxic byproduct, etc.•The recovery rates of lignin and hemicellulose were 77.5% and 89%, respectively.•We characterized the properties of three components for value-added use potential.

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 24 h 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 temperature 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.