An innovative method for pretreatment of sugarcane bagasse using sequential combination of supercritical CO2 (scCO(2)) and alkaline hydrogen peroxide (H2O2) at mild conditions is proposed. This method was found to be superior to the individual pretreatment with scCO(2), ultrasound, or H2O2 and the sequential combination of scCO(2) and ultrasound regarding the yield of cellulose and hemicellulose, almost twice the yield was observed. Pretreatment with scCO(2) could obtain higher amount of cellulose and hemicellulose but also acid-insoluble lignin. Pretreatment with ultrasound or H2O2 could partly depolymerize lignin, however, could not separate cellulose from lignin. The analysis of liquid products via enzymatic hydrolysis by HPLC and the characterization of the solid residues by SEM revealed strong synergetic effects in the sequential combination of scCO(2) and H2O2. (C) 2014 Elsevier Ltd. All rights reserved.