不同预处理方法对玉米秸秆纤维素结构及降解的影响

Effect of Different Pretreatment Methods on the Cellulose Structure and Degradation of Corn Straw

为高效利用玉米等作物秸秆中的纤维素,研究通过对玉米秸秆进行粉碎60目、膨化粉碎200目、超细200目、膨化超细400目、超声波预处理,并对其预处理结果采用扫描电镜观察分析得知,经膨化超细400目处理后的秸秆纤维素丝状结晶结构解体最明显。进一步对其中4种不同预处理后的秸秆做碱法水解,以获得可溶性糖的质量分数为指标,考察不同组合固液比、温度、碱质量浓度、水解时间对4种预处理秸秆的作用情况,确定玉米秸秆纤维素最佳预处理方法及碱法水解的最优条件。结果显示,超细200目预处理后的玉米秸秆碱水解液可溶性糖质量分数最高。优化的碱法水解条件为:水解时间90 min;温度110℃;NaOH质量浓度0.02 g/mL,固液比1∶23。在此条件下,可溶性糖的质量分数最高可达12.1%。

For the efficient utilization of the cellulose in corn and other crop residues,the corn stalks were crushed to 60 meshes,puffed crushed to 200 meshes,ultra-fine 200 meshes,400 meshes extruded ultra-fine,pretreated ultrasonically and analyzed by scanning electron microscope.The result found that the most obvious of the disintegration of the filamentous crystal structure was in ultra-fine 400-mesh pretreated of straw cellulose.Further,in order to determine the best pretreatment method and the optimal conditions of alkaline hydrolysis of corn stalk cellulose,the soluble sugar content was used as an indicator to investigate different combinations of solid-liquid ratio,temperature,alkali mass concentration,hydrolysis time on four different pretreatments of the corn straw alkaline hydrolysis.The results showed that the mass fraction of soluble sugar in alkaline hydrolysis liquid of corn straw pretreated to ultra-fine 200 meshes was the highest.Optimum condition for stalks of corn in alkaline hydrolysis was as follows： hydrolysis time 90 min,temperature 110℃,NaOH mass concentration 0.02 g / mL,solid-liquid ratio 1 ∶ 23.In this condition,the mass fraction of soluble sugar content could reach 12.1%.