【作者】 王艳玲；

【导师】 刘圣勇；

【作者基本信息】 河南农业大学 ， 农业生物环境与能源工程， 2012， 硕士

【摘要】 沼气作为一种重要的生物质能，是可再生能源的重要组成部分。沼气由于最初发现于沼泽中，故名沼气。沼气是利用粪便、农作物秸秆等有机物在厌氧的条件下，经过微生物生理代谢产生主要成分为CH₄和CO₂，还有少量的H₂、H₂S、CO等可燃性气体，属生物质能源。通过厌氧发酵可杀死秸秆等发酵原料中的病源虫卵，故发酵后的沼液是很好的液体有机肥料，可以用沼液喷施蔬菜、果树和农作物，除具有良好肥效外，还有抗寒、抗病虫害和增产的作用。沼渣是沼气发酵后剩余的半固体物质，其中含有丰富的有机质、腐殖酸、氨基酸、氮、磷、钾等微量元素；它可以作为土壤的改良剂，减少使用化学肥料带来的环境污染，促进生态农业建设。开展沼气发酵的研究有着重大的意义和作用。落叶沼气发酵实验主要分为两个部分：一个部分是发酵原料的预处理实验，另一个部分是厌氧发酵实验，而提高沼气发酵的效率的关键是优化落叶预处理条件和厌氧发酵条件。目前研究人员在用单一方式来预处理农业废弃物方面取得了一定的进展，据此提出可以考虑将物理、化学、生物三种预处理方法结合起来共同作用来预处理制备沼气的生物质的研究思路，为提高厌氧生物转化效率探索一条新的技术途径。另外，通过改变发酵物料的总固体浓度、发酵反应温度和发酵料液的pH得出沼气发酵的最佳工艺条件。（1）落叶预处理实验选取Ca（OH）/₂添加量、菌剂添加量、堆沤时间三个相关的因素进行实验，利用响应面法分析的Box-Behnken实验设计的原理进行安排17组实验，经过二次回归模型建立及方差分析，以及Ca（OH）₂添加量、菌剂添加量、堆沤时间两两因素对沼气总产气量的影响分析，利用软件分析得出最佳的预处理实验条件，为厌氧发酵实验进行提供先决条件。（2）落叶的厌氧发酵产沼气实验选取发酵温度、总固体浓度、料液PH值三个因素，采用拟水平的正交表进行实验。通过对容积产气率的极差分析得到厌氧发酵的最优组合。（3）通过分析各处理厌氧发酵的总产气量，原料产气率对落叶具有的厌氧发酵潜力进行评定。（4）对各处理沼气日产气量分析，分析沼气产生的变化规律。（5）对各处理的甲烷含量的趋势进行分析，其呈现先明显增加，增加达到一定值后有较小幅度的下降趋势，最大甲烷含量是处理9厌氧发酵的第17天得到的，其值为56.8%。并根据各处理沼气日产量和甲烷含量的趋势分析它们之间的联系。（6）运用Cubic函数对处理4和处理9的沼气日产气量和发酵天数进行拟合，分别得出各自的拟合方程，并对比厌氧沼气发酵的沼气日产气量实际值与拟合曲线上的理论值。更多还原

【Abstract】 Biogasis a kind of important biomass, and is an important component of renewableenergy. It isoriginally found in the swamp, so it is called biogas. Microorganisms use dung, cropstalks and other organic compounds to produce biogasin anaerobic environment.Biogas whichbelongs to biomass energy mainly includes CH4and CO2, a littleH2,H2S,COand other flammable gas.Anaerobic fermentation cankill pathogens eggs hiding in the straw and other organic matter, sobiogas slurry is a kind ofliquid organic fertilizers.When biogas slurry is used to spraying vegetables,fruit trees and crops, it not only could fertilizer efficiency, but also it could against the cold, reducepests and diseases increase yields. The biogas residue is emi-solid material left after methanefermentation, which is rich in organic matter, humic acid, amino acids, nitrogen, phosphorus,potassium and other trace elements. It can be used as soil improvers to reduce environmentalpollution caused by chemical fertilizers, and promote the construction of ecological agriculture. Thestudy of the methane fermentation has great significance and plays an important role.Deciduous fermentation experiment is divided into two parts: one part is the raw material’spretreatment experiments, another part is anaerobic fermentation experiments. The key to improvethe efficiency of methane fermentation is to optimize deciduous pretreatment conditions andanaerobic conditions. Researchers has made some progress in the pretreatment of agricultural wastewith a single way, so we propose using physical methods, chemical methods, biological methodstogether to carry out pretreatment experiments.in order to explore a new way to improve theanaerobic biological conversion efficiency. In addition, a greater number of deciduous aren’texploited.By altering the total solids concentration, the reaction temperature and the pH try to gainthe optimum conditions for methane fermentation.(1)Deciduous pretreatment select addition quantity ofCa(OH)2、addition quantity of bacteriumandretting days and arrange experiments by using Box-Behnken experiment design. Deciduouspretreatment includes17experiments.After the quadratic regression model and analysis of variance,it can analyzeaddition quantity ofCa(OH)2, addition quantity of bacterium andretting days influenceon the total gas production of biogas. Using software analysis can get the best pretreatmentexperiment, and prepare for the anaerobic fermentation experiment.（2）The anaerobic fermentationexperiments of deciduous select the fermentation temperature, totalsolids concentration, pH value as the influence factors. They are optimized by the quasi-level horizontal orthogonal testing method. We could get the optimal combination of anaerobicfermentation by the range analysis of volumetric gas production rate.(3)We could estimate the potential of anaerobic fermentation of deciduous by analyzing the totalgas production and raw material gas production rate.(4) Discuss the change law of biogas by the analysis of daily outputof biogas.(5) The trend of the methane content increased significantly at first. When it reached a certainvalue, it started to decrease gradually.The value of the maximum methane content is56.8%, whichoccurred at the17thday in the anaerobic fermentation. And analyze the relation between daily outputof biogas and the methane content.(6)Use the Cubic function to fit the treat4and9biogas, and we could get two fittingequations.Compare the actual values to the theoretical values from fitted curve.更多还原