Energy Efficiency in Enzymatic Hydrolysis: Study with Different Pretreated Biomasses

Enzymatic hydrolysis experiments were performed using Steam Exploded Sugarcane Bagasse (SESB), Hydrothermal Sugarcane Bagasse (HSB), and Hydrothermal Sugarcane Straw (HSS) biomasses. The study evaluated the energy efficiency based on glucose conversion and energy consumption throughout the process. The enzymatic hydrolysis experiments were performed in a 3 L stirred tank reactor equipped with two elephant ear impellers under the following conditions: 10% (m v−1) pretreated biomass, enzyme load of 10 FPU gsubstrate−1, pH 4.8, 50 °C and 470 rpm for 96 h. Energy consumption was determined experimentally using a dynamometer and monitored throughout the reaction. Rheological data were obtained with a digital rheometer during hydrolysis. Samples were taken at predetermined intervals for glucose analysis and to obtain rheological data. The glucose concentration (CG) at 96 h were 35.9 g L−1 (SESB), 45.4 g L−1 (HSB), and 49.8 g L−1 (HSS). The energy efficiencies (kgglucose kWh−1) obtained were 0.40 (SESB), 0.27 (HSB) and 0.28 (HSS). The energy efficiency with SESB was 41% and 46% higher than the experiments with HSS and HSB, respectively. The results of this study indicate that energy consumption during enzymatic hydrolysis is a critical factor influencing the process efficiency and viability.