【作者】 任天宝；

【导师】 张百良； 宋安东；

【作者基本信息】 河南农业大学 ， 农业生物环境与能源工程， 2007， 硕士

【摘要】 本文对玉米秸秆发酵生产燃料乙醇进行了系统地研究。通过试验确定了玉米秸秆预处理最适条件,并在自主设计组装的15L微型糖化罐中进行了纤维素酶和木聚糖糖酶的酶解糖化的最适条件的研究。在对糖化液成分分析及预处理后的玉米秸秆进行了扫瞄电镜的表面结构的微观分析基础上,进行了玉米秸秆糖化液的发酵前预处理和秸秆糖化液的发酵条件,以及构建双菌株发酵体系进行了研究。最后利用BOX-WILSON的中心组合设计对发酵条件进行了优化试验,并在此基础上研究并建立了嗜鞣管囊酵母的发酵动力学模型。本文的主要结论:1)玉米秸秆稀酸预处理的最适工艺条件:用60～80目的玉米秸秆粉,经0.5%的稀盐酸浸润,初始液固比为6,在125℃条件下处理60min后,玉米秸秆的结构组织明显被破坏,且初始水解糖化率达到21.5‰2)酶解糖化的最佳工艺条件:将预处理过的玉米秸秆,加入pH4.8磷酸缓冲液并调整液固比至10,添加0.04g%Mg²⁺糖化辅助因子,3%纤维素酶和3%木聚糖酶,在48℃的糖化罐中酶解糖化46h。反应结束后玉米秸秆总糖化率达到55.6%。3)将玉米秸秆糖化水解液加入4%（相对于秸秆质量）的活性炭后煮沸6-8min,掠去上面的泛青色的泡沫状物质,经定性滤纸过滤后,调整pH值到5.0±0.1,然后分装于300ml的三角瓶中各100ml,121℃灭菌15min后,冷却至室温,再分别接5%的酒精酵母和25%的嗜鞣管囊酵母P-01,在28℃、120rpm条件下发酵68-70h后,乙醇浓度到达1.4%。4)通过BOX-WILSON的中心组合设计确定了秸秆糖化液的最适发酵工艺条件:目前得到最佳发酵培养基:尿素0.1%,吐温80 0.75%,磷酸氢二铵0.05%,PEG 0.05%,在此条件下发酵终止时乙醇浓度到达1.5%。在此基础上进行了发酵过程理论探讨,分别建立了酵母生长、乙醇生成和还原糖消耗数学动力学模型。更多还原

【Abstract】 The fuel ethanol production with corn stalk was discussed in this thesis. The optimal pretreatment conditions of the corn stalk were determined in this thesis, And the optimal conditions of saccharification by cellulose. On the basis of Saccharification of the liquid component analysis and processing of corn stalk remnants of the scanning electron microscope on the surface of the micro-structure .Based on the analysis, the fermentation conditions of the cornstraw for constructing double yeasts system were studied. At the last of this thesis , the fermentation conditions were optimized through the BOX-WILSON center of combination experiment, and the yeast fermentation kinetic modes were eastablished.The main conclusions of this thesis included the following four parts:Firsterly,the following was of the optimal conditions of the pretreatment: With 60-80 meshes flour of corn stover ,with initial liquid to solid ratio of 6,under the role of 0.5% hydrochloric acid concentration, at the temperature of 125℃for 60 mins after pretreatment ,The corn stalk organizational structure was significantly damaged, and the initial hydrolysis rate reached 21.5%.Secondly, the following was of the optimal conditions of glycosylated enzyme reaction: The corn stalk pretreated was added pH 4.8 phosphate buffer, and adjusted to the ratio of liquid to solid 10 ,then added 0.04% Mg²⁺、3% cellulose and3% xylanase. At the temperature of 48℃for 46h after glycosylated reactions, the total hydrolysis rate reached 55.6%.Thirdly,the liquid of cornstalk glycosylated hydrolyzate was boiled for 6-8mins with adding of 4% actived carbon ,and the pan-like green was snatched above the bubble-like material ,then was filtered by qualitative filter paper and adjusted the pH value of 5.0±0.1. The Glycosylated liquid was Packed in 300 ml each of which 100ml flask, sterilizated at the 121℃for 15 mins,then 5% of alcohol yeast and 25% of Aeromonas tanning capsule of yeast P-01 respectively. At the temperature of 28 ℃for 70h after fermentation , the concentration of ethanol reached 1.4%.Fourthly, by the BOX-WILSON center of the design to determine the composition of straw on the optimal saccharification fermentation process : Now the test optimization fermentation medium, 0.1% urea, 0.75% Tween-80. 0.05%diammonium phosphate, 0.05% PEG. At the end of fermentation ethanol concentration reached 1.5% .on this basis study Aeromonas tanning capsule of the yeast fermentation kinetic model was eastablished.更多还原