【作者】 谢琳；

【导师】 周俊虎； 程军；

【作者基本信息】 浙江大学 ， 工程热物理， 2006， 硕士

【摘要】 随着环保要求的日益严格和化石能源的日益短缺，氢能作为清洁高效的可再生能源受到人们的普遍重视。本文针对固体有机废弃物进行了厌氧发酵产氢实验研究，利用TRACE GC色谱仪分析发酵过程中产生的气相及液相成分及含量，以研究微生物发酵产氢的特性。 本文首先选用西湖底的厌氧活性污泥、产气肠杆菌、污水处理厂的淤泥、沼气池发酵液以及猪粪等不同菌群对废弃食物——马铃薯进行厌氧发酵产氢特性实验研究，得到马铃薯在各不同菌群及工况下的发酵产氢能力，同时发现产氢菌间的协同作用很重要，在控制好发酵条件的情况下，产氢菌群发酵通常会好于单一产氢菌的发酵。 其次从不同废弃食物发酵产氢特性研究的角度，采用厌氧活性污泥为接种物，以马铃薯、青菜和米饭3种富含不溶解碳水化合物的废弃食物作为培养基料，对其发酵产氢特性进行了试验研究。发现马铃薯、青菜和米饭的发酵降解率分别为45.7％、89.2％和30.5％，每克已降解干物质的产氢量分别为：82.4ml·g^-1、62.6ml·g^-1和37.7ml·g^-1。气相样品中均没有CH₄产生，说明将厌氧活性污泥预先煮沸30分钟能有效抑制产甲烷菌同时保持产氢菌的活性。反应过程中控制发酵液pH值为4.5左右，发酵液相产物中乙醇一直占主导地位，其浓度远大于其它挥发性脂肪酸的浓度，但是在发酵后期，随着丙酸含量有所增加产氢量逐渐减少。 最后采用厌氧活性污泥为接种物，以水葫芦为发酵底物进行产氢实验研究。试验结果分析表明：H₂含量在10％～20％之间，气相样品中均没有CH₄产生。在本实验的发酵条件和所取淤泥发酵产氢时，pH值为5.5时的发酵产氢要优于pH为4.5时的发酵产氢能力；55℃的发酵温度要优于35℃的发酵温度；1：1的底物接种物比例发酵要优于3：7的底物接种物比例发酵。在发酵底物经水解酶预处理、底物与接种物比例为1：1、发酵温度为55℃、初始pH值为5.5的条件下获得最大产氢量，实验得到每克已降解干物质的最大产氢量为122.3ml·g^-1。液相色谱分析表明：各底物的发酵液产物中富含乙醇、乙酸、丙酸和丁酸等挥发性有机酸，且含量以乙酸居多，没有发现戊酸的生成。更多还原

【Abstract】 Biogas is a potential alternative fuel that is renewable in nature and thereby does not contribute to the net atmospheric concentration of the greenhouse gas. It is a colorless combustible gas produced by the fermentation of biomass and other wastes. Three times experiments have been studied aiming at the solid organic waste hydrogen fermentation. To investigate the mechanisms of biohydrogen production by anerobic fermentation of solid organic waste, gas chromatography is used to analysis the biogas and volatile fatty acid in anaerobic bio-reactor.Firstly, the ability of hydrogen production by digested sludge from the West Lake, Enteobacter aerogences, digested sludge from sewage farm, the fluid of methane pool and dejecta （pig） have been studied. The rule of the ability of hydrogen production by different bacteria under different control condition. Simultaneity, the importance of the synergistic effect on hydrogen production has been proved. Under the same suited control condition, the hydrogen production of the mixed cutler is higher than the single one.Secondly, the biohydrogen production from three food wastes mainly composed of undissolved carbohydrates by anaerobic fermentation of digested sludge is studied. It is found by experiments that the degradation rates of potato, greengrocery and rice in the fermentation are respectively 45.7%, 89.2% and 30.5%. The biohydrogen yield of per gram of dried potato, greengrocery and rice are respectively 82.4 ml·g^-1, 62.6 ml·g^-1 and 37.7 ml·g^-1. No methane is detected in the biogas, because the methane-producing activity is restrained and the hydrogen-producing activity is simultaneously kept when the digested sludge is preheated in the boiling water for 30 min. Ethanol concentration is much higher than other volatile fatty acids in the fermentation solution when the pH value is controlled around 4.5. The biohydrogen production rate firstly increases to a peak and then decreases with an increase of propionic acid concentration in the fermentation solution.Finally, the extraction of hydrogen from the fermentation of eichhornia crassipes by digested sludge is demonstrated. The results show that: The contents of H₂ and CO₂ are 10%～20%, 75%～90% and no CH₄ respectively. Ethanol, acetate, propionate and butyrate are detected, and the trace of valerianate is not found in the liquid of fermentation. Associated with the hydrogen production potential, the pH value of 5.5 is better than that of 4.5, the fermentation temperature of 55 ℃ is better than that of 35 ℃ and the food-to-microorganism ratio of 1:1 is better than that of 3:7 . The high hydrogen production potential of 122.3 ml·g^-1 occurred when the pH value of fermentation liquid is 5.5, the fermentation temperature is 55℃ and the food-to-microorganism ratio is 1:1.更多还原