导　　师： 张焜

学科专业： 081702

授予学位： 硕士

作　　者： ;

机构地区： 广东工业大学

摘　　要： 玉米芯作为一种丰富廉价的植物纤维资源,可以代替有限的粮食原料发酵生产燃料乙醇,在开发新能源和环境保护等方面具有重要的经济效益和社会效益。本文对玉米芯预处理工艺、酶解工艺和发酵制备燃料乙醇工艺进行了研究。采用微生物方法和纤维素酶法,利用玉米芯发酵生产燃料酒精,为玉米芯的综合利用开辟一条新的途径。 建立纤维素发酵酒精工艺优化过程中的相关标准,包括中间产物还原糖的检测和最终产物酒精的定性定量分析方法。确立DNS法测定还原糖含量。针对玉米芯为原料,从最大吸收波长、显色时间、显色剂用量的条件考虑,确立其最大吸收波长为500m,显色2min,显色剂用量为2.0mL。建立准确的酒精定性定量分析方法,酒精的定性分析采用气相色谱保留时间法,酒精的定量分析采用气相色谱内标法。气相色谱法定性分析酒精的保留时间约在2.0min处,正丙醇的保留时间约在5.6min处；内标法定量分析酒精的得率,其线性方程为y=7.4211x-1.1182/(R2=0.995/). 研究玉米芯预处理工艺条件,采用单因素和正交实验结合的方法,对玉米芯进行水解,考察了硫酸质量分数、预处理时间及料液比对玉米芯水解的影响。各个因素对预处理玉米芯的影响顺序为料液比>预处理时间>硫酸质量分数,最佳预处理水解条件为1.0/%H2SO4.预处理时间为1h、料液比为1：12。采用扫描电镜和红外光谱,观察稀硫酸预处理水解玉米芯后的形貌变化。结果表明：稀硫酸预处理水解后玉米芯纤维的结晶结构被明显破坏。 以玉米芯玉米芯为原料,微生物法研究采用以本实验室筛选的纤维素降解菌株嗜麦芽寡养单胞菌LⅡ和爪哇正青霉L2”为降解菌种,实验结果显示,菌株L2”的效果优于LⅡ,故选用L2”菌株,其最佳菌用量为30ml,调节pH值为7.0左右,酶解温度35℃,水解48h后葡萄糖浓度达到� Corncob can be used to Produce fuel ethanol as a cheap and abundantly available lignocellulosic resource instead of limited grain feedstocks. Bioconversion of corncob to fuel ethanol is very meaningful in the aspects of new energy development and environmental protection.In this thesis, technologies in pretreatment of corncob, enzymatic hydrolysis, ethanol production from cellulosic hydrolysate, were investigated. The technology of producing alcohol from corncob by microorganism and cellulase methods was studied. It breaks a new way to make the full use of corncob. Serials of standards were built to check the intermediate and final product. The standards including the follow:the glucose's concentrations and the yields of the ethanol. The dinitrosalicylic acid reagent/(DNS/) method was chosen to check glucose's concentration and the factors including sensitive wavelength, boiling time and the dosage of dinitrosalicylic acid reagent which influence the results when the raw material was corncob were studied. As the results show, it is suggested that 500nm is more sensitive wavelength for determination, the boiling time for developing should be 2min, the dosage of dinitrosalicylic acid reagent is 2.0mL. Build an accurate way for the qualitative and the quantitative analysis of ethanol content. The result is analysis by the Gas chromatography. The qualitative analysis is by the retention time and the quantitative analysis by the internal standard method. The gas chromatography retention time of ethanol is 2.0min,and the retention time of n-propanol is 5.6min. The internal standard method showed the linear equation of peak area was y=7.4211x-1.1182 /(R2=0.995/). The factors including concentration of sulfuric acid, pretreatment time and feed-to-liquid ratio, and the orthogonal experiment are studied for optimizing the hydrolysis of corncobs. The effective sequence of each factor on corncobs pretreated is feed-to-liquid ratio> pretreatment time> concentration of sulfuric acid, and the optimal conditions are as

关 键 词： 玉米芯 预处理 微生物菌 纤维素酶 乙醇发酵

领　　域： [化学工程]