玉米芯水热预处理对纤维素结构的影响

doi:10.12066/j.issn.1007-2861.1684

Abstract

Abstract:

To solve the problem of high costs in pretreatment, secondary pollution and complicated subsequent purification, solid CO₂ was added as an auxiliary medium under hydrothermal pretreatment conditions. The effects of operating conditions including temperature, time and the amount of solid CO₂ on the cleavage behavior of cellulose and lignin removal were investigated. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) were used to analyze the structural variation of cellulose, which had great significance of theoretic instruction to optimize the pretreatment process. The results show that cellulose chain cleavage basically occurs when the temperature exceeds 160°C. As temperature rises to 180°C, degree of polymerization (DP) decreases dramatically, and the removal of lignin reaches the highest (31.6%). From the analysis of FTIR, peaks associated with C—O—C bonds are weakened in pretreated samples, indicating that glycosidic bonds and chains of cellulose are broken down during the pretreatment process. Further analysis by XRD shows an increase in crystallinity of cellulose in pretreated corncob, indicating removal of the amorphous part of cellulose, and transition of cellulose Ⅰto cellulose Ⅱduring pretreatment.

Key words: removal of lignin, structure of cellulose, degree of polymerization, hydrothermal pretreatment, solid CO₂

ZHANG Li, WANG Zheng, SHU Sitao, GUO Xiaoya. Influence of hydrothermal pretreatment of corncob on structure of cellulose[J]. Journal of Shanghai University（Natural Science Edition）, 2017, 23(3): 464-472.

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Influence of hydrothermal pretreatment of corncob on structure of cellulose

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