【作者】 唐大惠；

【导师】 任保增；

【作者基本信息】 郑州大学 ， 化学工艺， 2005， 硕士

【摘要】 氢气是一种清洁的可再生能源,在燃烧过程中除生成水外,不产生导致环境恶化的碳基化合物。近年来,随着人们对能源的需求剧增,石油价格持续攀升,能源短缺和环境污染问题已对我国经济的可持续发展带来严峻的挑战。因此,寻找替代能源、开展可再生能源的研究,对于维护国家的能源战略安全、减少环境污染具有十分重要的意义。生物质厌氧发酵生物制氢技术利用微生物分解有机废弃物制备氢气,起到了除废和环保的双重目的,因而具有良好的应用前景。 本文在批式实验研究成果的基础上,以农业废弃物玉米秸秆为产氢原料,以牛粪堆肥为产氢菌源,在5立升规模的混合式制氢反应器中通过厌氧发酵产生氢气,取得了有意义的研究结果。 1.以牛粪堆肥作为天然厌氧微生物来源,用蔗糖作为菌种培养驯化的底物,研究了产氢菌种的富集方法、培养方式和驯化条件。结果表明:先煮沸菌源溶液15min,接着曝气2h,经这种方法处理过的菌源富集产氢菌种效果好,接种到反应器中反应产氢能力达到141.86ml/g,接种后仅10h开始产气;提出采用半连续培养方式对菌种进行培养,当培养时间12h时,用更换新鲜培养液或者添加NaOH的方法控制pH值,能提高菌种活性,同时产氢能力增加;当对菌种驯化培养时,控制容积负荷在50±2g/（1·d）较为适宜,此时产氢能力高达175.14ml/g,反应器产氢速率150.93ml/（1·h）,平均氢浓度为54.88%,COD的平均去除率30%。 2.在5升规模的制氢反应器中,研究了玉米秸秆厌氧发酵产氢工艺,对有关工艺参数进行了探索。实验结果表明该工艺在5升规模反应器中的适宜运行参数为:温度:36±1℃,反应pH值:5.2～5.4,搅拌转速:100～120r/min,初始秸秆浓度:10g/1,进料时间间隔:8～9h。在适宜的运行条件下,玉米秸秆生物制氢在该反应器的最高持续产H₂能力为103.45ml/（1·h）,最高比产氢率为108ml/g秸秆,生物气中平均氢浓度45%。分析了反应的代谢产物,主要发酵（酸化）产物为挥发性脂肪酸（乙酸和丁酸）、氢气、二氧化碳和代谢的末端产物。气相中没有检测到甲烷。液相代谢产物中丁酸含量始终比较高,可以判定玉米秸秆生物制氢在该5升反应器内的发酵类型属于丁酸型发酵产氢。更多还原

【Abstract】 Hydrogen is a clean renewable energy.In the process of burning it only produces water without carbon-based emissions that contribute to environmental pollution and climate change. Currently, with the more requirement to energy and the increasing price of petroleum,the problem of energy shortage and environmental pollution brings challenge to sustainable development of our nation economy.So,it is very significative to find some new substituted energy,develope the study of renewable energy for protecting the security of energy strategy and reducing the environmental pollution.In this process, micro-organisms degrade organic wastes to produce hydrogen.It reaches two aims: getting rid of wastes and protecting environment.So it must have a good future.Based on the results of the batch test, biohydrogen production has been carried out in a 5-litre mixed reactor from agricultural organic wastes(cornstalk) by natural anaerobic microorganisms,we got the significant study result.1. The method of enrichment, culture and the condition of acclimation was investigated with natural anaerobic microorganism bacterium from cow dung compost, the sucrose as substrate. The results showed that it was effective that the compost was boiled for 15 min and then aerated for 2 hours to harvest hydrogen bacteria, the hydrogen productivity was 141.86 ml/g,gas production began after only 10 hours; semi-continuous culture method was introduced, at time points of 12 hours after the bacterium was inoculated, fresh culture medium or sodium hydroxide were added to control the pH, the results showed that the hydrogen productivity of substrate was increased and activity of the bacterium was enhanced; the loading rate of volume 50 ±2g/(1.d) was optimal when acclimating microorganism, under the conditions, the reactor obtained a hydrogen yield of 150.93ml/(1.h),the maximum hydrogen productivity was 175.14ml/g,the hydrogen average concentration in the biogas reached 54.88%,the COD removal efficiency could reach 30%. 2. Biohydrogen production has been carried out in a 5-litre scale-up reactor from cornstalk by natural anaerobic microorganisms. In order to develop the biohydrogenproduction technology, the engineering technique parameters were researched in this thesis. The optimal operation condition and some controlling parameters can be determined as follows:T36± 1 °C, pH 5.2~5.4,speed of agitator 100~120r/min,initial concentration of cornstalk 10g/l,interval of feeding 8 ~ 9h.Under the optimal experimental conditions, the results showed that the scale-up reactor obtained a hydrogen yield of 103.45 ml/(l-h) continuously, the maximum hydrogen productivity of cornstalk was 108ml/g,the average hydrogen concentration in the biogas reached 45%. Experimental results of metabolites analysis demonstrated that there were acetate, butyrate, ethanol, H2, CO2 and the terminal-product. Methane was not be detected in the biogas. Because the butyrate concentration was the highest in all liquid phase-products at all times, it might be butyrate acid type fermentation that biohydrogen production in the 5-litre scale-up reactor.更多还原