Methane Production from Hydrogen Peroxide Assisted Hydrothermal Pretreatment of Solid Fraction Sugarcane Bagasse

To improve the efficiency of hydrothermal pretreatment for better methane production and minimizing sugarcane bagasse recalcitrance, hydrogen peroxide was studied as an impregnation agent before hydrothermal pretreatment. Hydrothermal pretreatment was conducted employing three factors: temperature (160, 180, 200 degrees C), time (5, 12, 19 min) and hydrogen peroxide concentration (2, 4, 6 % v/v) by central composite design. Pretreated solid fraction resulted in a maximum of 73.1% delignification, 75.8% xylan removal besides 139.5% glucan increase. Liquid fraction was observed with 3005.63 ppm of total phenolic content, 17.7 g L-1 CODs (Soluble Chemical Oxygen Demand) along with minimal concentrations of 5-hydroxymethylfurfural (0.01-0.06 mg mL(-1)), furfural (00.06 mg mL(-1)), and acetic acid (0.11-0.58 mg mL(-1)). Digestion experiments resulted in 323.3 NmL g(-1) TVS methane in comparison to 147.8 NmL g (-1) TVS for raw bagasse. Most abundant bacterial genera identified were uncultured AUTHM297 (Thermotogales) whereas Methanosaeta were the abundant methanogenic archaeal genera. The study resulted in a 118.64% increase in methane production in comparison to raw bagasse indicating the importance of the impregnation step before hydrothermal pretreatment.