Reducing sugars production from sugarcane bagasse wastes by hydrolysis in sub-critical water

Biomass is an important renewable and sustainable source of energy. The rational utilization of biomass wastes is important not only for the prevention of environmental issues, but also for the effective utilization of natural resources. Reducing sugar, as a biomass energy precursor, can be further transformed to fuel alcohol in a fermentation process. Sub-critical water is an environmentally friendly solvent and attractive reaction medium. This study deals with the production of reducing sugar from sugarcane bagasse by hydrolysis in sub-critical water and the hydrolysis kinetics of sugarcane bagasse. Kinetics was conducted in a temperature range of 200–240°C using a 200-ml stainless steel batch reactor. A simplified kinetic model based on a parallel and consecutive reaction was proposed. The differential equations resulting from the model were fit to experimental data to obtain kinetic rate constants. The activation energy and the pre-exponential factor were determined. A good agreement between the simplified model and the experimental data was obtained. The experimental results show that the best hydrolysis technology involves a reaction temperature of 240°C, and a reaction time of 120 s. Under these conditions, the reducing sugar yield reaches 61.5%.