Studies Of ⁶⁰Co_γ Irradiation Fiber Degradation Of Corn Straw And Its Mechanism

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.