【作者】 易锦琼；

【导师】 熊兴耀；

【作者基本信息】 湖南农业大学 ， 园艺学， 2011， 硕士

【摘要】 采用成本低廉、来源广泛的木质纤维素作为原料生产燃料乙醇是今后生物质能源发展的重要方向。但天然的木质纤维素结构复杂,反应活性低,难以糖化。因此,要对木质纤维原料进行适当的预处理,改变其结构,提高纤维素的可及度和反应活性。辐照作为一种物理手段,能降低纤维素的结晶度,使其结构松散,增大有效反应面积,提高降解转化率。该方法具有处理时间短、操作简单、能耗低、不污染环境等特点。本研究以60Coγ为辐射源,研究了0-2000kGy辐照剂量对玉米秸秆的影响,研究结果表明：玉米秸秆的质量损失随辐照剂量增加而增大;经过400、800、1200、1600、2000kGy的辐照剂量处理后,玉米杆和玉米叶的结晶度依次为12.15%、10.82%、10.28%、9.76%、8.86%和19.81%、12.73%、9.65%、9.16%、3.85%。辐照处理不会改变玉米秸秆纤维素的晶体类型,但对结晶度有一定的影响；辐照改变了玉米秸秆的化学组成,最佳的处理剂量为2000 kGy,玉米杆和玉米叶中纤维素、半纤维素、木质素百分含量分别为8.26%、2.74%、2.88%和9.5%、0.17%、0.93%。辐照处理对木质素降解影响不大；较高剂量的辐照对玉米秸秆有明显的降解糖化作用,2000KGy剂量辐照后玉米杆和玉米叶的还原糖含量分别提高了69.88%,445.63%；辐照后玉米秸秆易于酶解,随着辐照剂量的增大,酶解产糖量显著增加。在较高剂量下辐照-酶解复合降解玉米秸秆效果优于单一的辐照处理和单一酶处理。更多还原

【Abstract】 The adoption of low-cost, extensive cellulose as a source of raw materials to produce fuel ethanol is an important direction for the development of biomass energy in future. It is hard to hydrolyze because of the complex structure and low reactivity of natural cellulose. Therefore, a proper pretreatment to cellulose materials to change the structure and to improve the reactivity becomes a necessity. Compared with traditional pretreatment, there are many advantages while using irradiation to treat natural cellulose. It results in degradation of cellulose featured by the decrease in the degree of polymerization, and loose in the structure, increases in the effective reaction area. Furthermore, this method is characterized by time-saving, simple processing, low-energy consumption and environmental-friendly and so on.This research made a study of the influence of the different-energy irradiation between 0 and 2000kGy on corn straw with the radiation source of 60Coγ. The results showed:The weight loss of corn straw increased at elevated irradiation doses; The crystal type were not changed by 60Coγrays irradiation treatment, but the irradiation treatment has a definite effect on the crystallinity of corn straw. The organism structures were destroyed by 400～2000kGy 60Coγirradiation, crystallinity level were 12.15%、10.82%、10.28%、9.76%、8.86% and 19.81%、12.73%、9.65%、9.16%、3.85%; The physical and chemical properties changed after irradiation.The optimum doses was 2000kGy; The higher dose of irradiation brings significant increase in the corn straw saccharification. Saccharification of 2000kGy gamma treated corn stalks and corn leaves give a higher 69.88%,445.63% increase in reducing sugar than untreated. At lower dose a slight increase reducing sugar has been found as compared to unirradiated sample. The result also indicates that enzyme combined with gama-irradiation treated on corn stalk, with the rise of radiation dose, the enzyme significantly increases sugar yield. Under high dosage, effect of combined gama-irradiation and hydrolysis treatment on corn straw better than sole radiation treatment and sole enzyme processing. Content of reducing sugar of corn stalks and corn leaves has been increased after irradiation, increasing the utilization rate of cellulose.更多还原