Research Progress in Radiation Pretreatments of Lignocellulose

In this paper, the effects and characteristics of several main irradiated pretreatment methods for lignocellulose are compared and summarized comprehensively. The mechanism of lignocellulose pretreated by microwave, ultraviolet, gamma ray, X ray, electron beam and ion beam were expounded. In particular, the transformation of polymorphys in lignocellulose (I_α → I_β) caused by pretreatment with heavy ion beams irradiation was discussed. The crystallinity index of lignocellulose was strongly correlated with enzyme digestibility. The pretreatment of heavy ion beam radiation can destroy the lignin and hemicellulose partially, resulting in an increase in its relative crystallization, which enhances the accessibility of cellulase and lignocellulose, also increase the enzymatic hydrolysis yield. Therefore, the biotransformation efficiency of enzyme to lignocellulose and the yield of reducing sugar can be significantly improved at the appropriate dose of heavy ion beam radiation pretreatment, which provides the theoretical guidance for radiation pretreatment to improve the comprehensive utilization of lignocellulose.