Characterization of Ball Milling Pretreated Corn Stover and Optimization Enzymatic Hydrolysis Parameters

摘要

Lignocellulosic biomass can be hydrolyzed into sugars by cellulase after ball milling pretreatment. The structural transformations before and after milling were analyzed via X-ray diffraction (XRD), microstructural morphology, thermogravimetric analysis (TGA), particle size distribution (PSD), and Fourier transform infrared spectroscopy (FT-IR). The results indicate that ball milling in mild alkaline solvent changes the chemical and physical structure of the cellulose in corn stover. The pretreated stover was then subjected to enzymatic hydrolysis. Box-Behnken design and response surface methodology were employed to design the experiments and optimize the hydrolysis yield, respectively. From an economic point of view, the optimum conditions for the enzymatic hydrolysis of corn stover are an enzyme concentration of 15 FPU, a substrate concentration of 10%, a temperature of 51℃, and a pH of 5.3. The results of the confirmation experiment under the optimum conditions agreed with the model predictions.