Structure and Enzymatic Hydrolysis Analysis of Corn Stover Pretreated with Different Pretreatment Methods

In the process of industrial transformation of straw, due to the complicated structural relationship of straw itself, the conversion efficiency is low. Therefore, different pretreatment methods are required to pretreat straw to destroy the inherent structure of the straw and improve its enzymatic efficiency. In this study, the effects of different pretreatments on the microstructure of corn stover were investigated by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). Moreover, the hydrolysis of different pretreated corn stover with cellulase was studied. It was showed that the surface and structure of corn stover were damaged in some extent in pretreatment. The surface of corn stover pretreated with NaOH collapsed mostly, which showed that the structure of lignocellulose was broken effectively. The pretreated corn stover was analyzed with Fourier transform infrared spectroscopy. It was show that the characteristic peaks of ligin at 1600 and 1510 cm(-1) disappeared for corn stover pretreated with NaOH, which indicated that the lignin was removed effectively. The peaks at 1744-1734 cm(-1) of pretreated corn stovers (the characteristic peak of C=O), which related to ligin and hemicellulose, reduced in different extent. It was shown that the lignin and hemicellulose were removed with different pretreated methods. Moreover, it was shown that the crystallinities of pretreated corn stovers changed in different extent with X-ray scanning. The crystallinity of corn stover pretreated with H2SO4 got the maxium value of 43. 4%. The effects of different pretreated methods were evaluated with corn stover hydrolysis by cellulase. The maxium value of glucose was 33. 32 g/L. This study provided basis for the efficient production of biochemicals with different pretreated corn stover.