3种预处理对青贮玉米秸秆理化特性的比较研究

Comparative study on physical and chemical properties of silage corn straw by three pretreatment methods

本研究对蒸汽爆破、热喷放及碱堆沤3种预处理方式处理的青贮秸秆的物理特性和理化成分进行了分析,测定了预处理后玉米秸秆在水中的沉降特征、亲水指数等指标,同时通过显微镜观察、红外光谱、X射线衍射及热重分析试验,对各种预处理方法进行了对比和评价。结果表明,青贮玉米秸秆经过3种不同预处理后,其理化特性明显不同。经蒸汽爆破之后秸秆表面呈现亲水特性,沉降比从原料的87.3%减少至0%,比表面积比原料增加65.2%;显微观察发现蒸汽爆破后秸秆细胞壁完全断裂破碎,纤维素结晶度下降至33.11%。蒸汽爆破相比其他2种方法更能显著改变玉米秸秆的结构,使其更利于降解,是一种理想的预处理方式。

In this study,the physical characteristics and physicochemical composition of the silage straws treated by 3 pretreatment methods,i.e.steam explosion,thermal spraying and alkali stacking were analyzed.The characteristics of sedimentation and hydrophilicity index of the corn stalk in water after pretreatment were measured.Various pretreatment methods,in the meantime,were compared and evaluated by microscopy,infrared spectroscopy,X-ray diffraction,and thermogravimetric analysis.The results showed that the physiochemical properties of silage corn stalks were significantly different after three different pretreatments.After steam explosion,the surface of the straw showed hydrophilicity,the sedimentation ratio decreased from 87.3%of the raw material to 0%,and the BET surface area was 65.2%higher than the raw material.Microscopic observation showed that the cell wall of the straw was completely broken after steam explosion and the cellulose crystallinity decreased to 33.11%.Compared with the other two methods,steam explosion can significantly change the structure of corn stalks and make them more conducive to degradation.In a word,ICSE is an ideal pretreatment method.