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生物质的结构和化学复杂性严重阻碍了木质纤维素生物质向乙醇的生物转化,这使得以生物质为原料生产纤维素乙醇成为挑战。通过建立良好的发酵技术,纤维素和半纤维素在水解为糖类组分时可转化为乙醇。然而,发酵过程必需的糖类会陷入木质纤维素的交联结构中。因此,生物质的预处理总是先除去和(或)改变木质素与半纤维素的周围基质结构,然后用酶法水解生物质中的多糖(纤维素和半纤维素)。预处理是指一种工艺流程,即将木质纤维素生物质从原来抗木质纤维素酶系统的形式转化为对纤维素水解作用更为有效的形式。一般预处理方法可分为三类,包括物理方法、化学方法和生物方法。本文强调的生物质预处理指的是为纤维素乙醇生产过程中酶法水解和微生物发酵的而做的准备。这一准备工序主要包括生物质结构和组分特征对预处理的影响,不同生物质预处理方法的特征,生物质预处理研究的状态、挑战及未来的研究目标。
The structural and chemical complexity of biomass severely hampers the bioconversion of lignocellulosic biomass to ethanol, making the challenge of producing cellulosic ethanol from biomass. By establishing good fermentation techniques, cellulose and hemicellulose can be converted to ethanol when hydrolyzed to a sugar component. However, sugars necessary for the fermentation process can fall into the crosslinked structure of lignocellulose. Therefore, pretreatment of biomass always first removes and / or alters the surrounding matrix structure of lignin and hemicellulose and then enzymatically hydrolyzes the polysaccharides (cellulose and hemicellulose) in the biomass. Pretreatment refers to a process that converts lignocellulosic biomass from the original form of an anti-lignocellulase system to a form that is more effective at hydrolyzing cellulose. General pretreatment methods can be divided into three categories, including physical methods, chemical methods and biological methods. The emphasis of this paper on biomass pretreatment refers to the preparation for enzymatic hydrolysis and microbial fermentation during cellulosic ethanol production. This preparation process mainly includes the influence of biomass structure and component characteristics on pretreatment, the characteristics of different biomass pretreatment methods, the status of biomass pretreatment research, the challenges and the future research goals.