【作者】 尤希凤；

【导师】 张全国；

【作者基本信息】 河南农业大学 ， 农业生物环境与能源工程， 2005， 博士

【摘要】 本研究是在国家863计划项目“太阳能生物制氢技术研究”(编号:2004AA515010)支持下开展的系列研究。能源短缺、环境污染是严重威胁当今人类生存的两大难题,开发可再生的清洁能源迫在眉睫,氢气以其能量密度高、可再生、以及洁净燃烧而被全球能源界公认为化石燃料的最佳替代者,在所有生产氢气的方法中,生物制氢以其生产条件温和(常温、常压中性pH值)、成本低廉(可利用工农业废弃物为原料)被认为最具发展潜力。光合细菌具有可降解多种有机物产氢不放氧、高原料转化效率和光转化效率、高纯度、高太阳光谱响应范围并且可与多种微生物共生建立良好微生物体系等特点,光合细菌太阳能生物制氢技术在生物制氢技术中占有重要的地位。 降低成本、提高转化效率、提供稳定的生产系统是实现生物制氢工业化进程的唯一途径,目前光合细菌制氢研究中多采用葡萄糖、苹果酸、乳酸、乙酸等为产氢原料,成本很高,本文主要研究以猪粪为原料的的光合细菌产氢技术,在降低成本的同时处理环境污染,一举两得;菌种性能的好坏是影响光转化效率和原料转化效率的根本因素,本文突破了在光合细菌产氢的研究中,多沿用资料报道的单株菌进行纯菌种产氢试验的弊端,进行了优势光合产氢菌群的系统筛选,采用原料不灭菌直接生产技术,初步解决了生物制氢的工业化进程中面临的混合优势菌群筛选及其产氢工艺等主要问题。 主要研究成果有以下几个方面: 1.根据各类光合细菌的生态特性和生理特征,在不同的季节,从具有代表性的6个地点获得24个典型样品,按照各类光合细菌的生长条件和营养需求,从培养基组成、pH值、光照强度,光照时间和周期、培养温度、厌氧状态几个方面设计出相应的培养基和培养条件,对光合细菌进行了广泛地富集和分离,获得33株光合细菌;按照猪粪的成分特点,对所分离出的33株光合细菌,进行了猪粪、相关小分子有机酸和葡萄糖利用能力研究,从中筛选出能较好地利用这三类基质的优势菌株作为初步筛选的结果;依据乙酸丙酸和丁酸是猪粪微生物转化的重要成分的原则,分别以这三种酸为产氢基质、以氢气产量为筛选标准进行产氢试验,筛选出7株高效产氢菌株;依据混菌培养具有原料利用广泛性的特点,研究了7株优势菌种的混合体系的产氢能力,结果表明7株优势产氢光合细菌所组成的混合菌群利用乙酸、丙酸和丁酸的产氢量分别为1590ml/g乙酸、2130ml/g丙酸和2520ml/g丁酸,高于大多数单株菌的产氢量,该氢气产量分别是乙酸、丙酸和丁酸的最大理论产氢量的95.7%、90.6%和89.0%,表明所筛选的优势光合细菌组合具有极高的原料转化效率。 2.依据影响光合细菌产氢的原理和工业化生产中低成本的需求,研究了以葡萄糖为基质利用高效产氢光合菌群生产氢气的影响因素,结果表明,高效产氢光合菌群产氢必须在光照、厌氧的条件下进行,高效产氢光合菌群的最佳产氢工艺条件是为:光照强度2000-60001x、温度28℃-34℃、pH值为5-8、接种量为10%-100%,添加氮源对产氢效果没有显著的影响,由于猪粪中含有大量的有机氮,表明猪粪产氢具有较好的工程应用前景。更多还原

【Abstract】 This paper is a series research supported by national "863" plan. People confront two serious problems of energy shortage and environment pollution nowadays. It’s urgent to develop renewable clean energy. Hydrogen was thought the best substitute for fossil energy as it’s high energy density, renewable and burning without pollution. Biological hydrogen was thought being most potential among all hydrogen production methods as it’s mild production conditions (normal temperature, Pressure and pH value) and low cost (use industry and agriculture waste as material). Photosynthetic bacteria (PSB) have many special characteristics such as decompose lots of organic to produce hydrogen without oxygen release, high material and light conversion efficiency, high production purity, wide answer range of sun light spectrum and can coexist with different microorganism to set up a good system. PSB hydrogen production with sun light play important role among biological hydrogen production technology.It’s the only way to realize industry biological hydrogen production that reduce cost, enhance convention efficiency, provide stable production system. Now most photosynthetic hydrogen production research using glucose, malate , lactate, acetate and so on as hydrogen production material lead high cost. This paper mainly focus on photosynthetic hydrogen production technology from hog manure to reduce cost as well as treating environment pollution. It has two advantages at the same time. Characteristics of strains used were the most important factor that affect material and light conversion efficiency. In this paper the problem of hydrogen production with using pure strain from reports was resolved , strain screening were carry out systematically, hydrogen production directly with non-sterilized material was realized, difficulties of screening advantage hybrid strain and study it’s hydrogen production technology lying in the process of biological hydrogen production industrialization were resolved preliminary. Main research result of this paper as following:1. 24 typical samples from 6 representative places at different seasons werecollected according their ecological and physiological characteristics of four kinds of PSB. Mediums and culture conditions accordingly were designed according their ecological and physiological characteristics of the four kinds of PSB including medium ingredients, pH value, light intensity, illuminate time and cycle, temperature, anaerobic condition . Enrichment and isolation of PSB widely were carried out. 33 PSB strains were isolated. Utilization abilities of hog manure, small molecule organic acid and glucose were studied . Strains with good utilization abilities of these materials were screened out as preliminary screening results. Hydrogen production experiment with acetate, propianate and butyrate were carried according these three acetate were the main ingredient resulting from hog manure pre-treatment. 7 strains were selected. Hydrogen production with the mix-culture of these 7 strains were studied according multi-culture had the advantage of better material utilization ability. The result proved that hydrogen productivities of the mix-culture of the 7 advantage strains from acetate, propianate and butyrate were 1590mlH2/g acetate, 2130mlH2/g propianate and 2520ml H2/g butyrate respectively, which were higher than most pure cultures. The productivity were 95.7%, 90.6% and 89% of their theory highest productivity. It proved that mix-culture of the advantage strains selected has high material conversion efficiency.2. Hydrogen production factor of efficiently hydrogen production PSB group (EPSBG) were studied with glucose as substrate according the affecting theory of hydrogen production and low cost requirement in industry production process. Anaerobic and illumination were required during hydrogen production with EPSBG The best hydrogen production conditions of EPSBG were as following: 2000-60001x illumination, 28-34 °C temperature, 5-8 pH value, 10-100% inoculation, nitrate addition has little influence on hydrogen productivity. This prove that hog manure has good industry applying prospect as hog manure has high nitrate concentration.3. Hydrogen production theory research discovered that EPSBG stopped growth during hydrogen production. There exit big difference from most PSB hydrogen production research. This showed that EPSBG had special hydrogen production theory and ways.4. Effects of different hog manure treatment methods on EPSBG hydrogen production were studied according physiological characteristics of EPSBG Dark aerobic treatment was found the best method. Hydrogen productivity with 4 days dark aerobic treatment was 24.1 times than the contrast group of glucose liquid. Smallmolecule organic aced test result of 4 days dark aerobic treatment showed that the concentrations of acetate and other 8 acids increased notably after treatment. The best technological conditions of hog manure dark aerobic treatment as following: 20-35 *C, 50% inoculation , 4cm high hog manure input with triangle bottle in the lab and natural pH value.5.Effects of main technological parameters and different cross-linking agents treatment of EPSBG immobilization by alginate calcium on hydrogen production were studied according to the aim of reducing cost, simplifying control, and improving photo-bioreactor efficiency. The results showed that the immobilized cell was more stable than separate cell and showed longer hydrogen production activity. Four different cross-linking agent showed notable influence on activity and stability of immobilized cell. Dealing with polyacrylamide and glutaraldehyde showed best. Glutaraldehyde concentration of 0.7%, 10:3 ratio of alginate sodium to cell weight(dry) were determined best parameter, and also proved that reducing the size of immobilization cell lead to higher hydrogen productivity. Additional hydrogen of 94.7% of 5mm grain were reached comparing to 3mm grain. 51% cell activity and 75 days stable hydrogen production of immobilized cell were obtained.6.Batch and continuous enlarge hydrogen production experiment were carried out in a 7L photo-bioreactor with the immobilized EPSBG from pre-treatment hog manure with 5000mg/L TCOD. Following result were reached: in batch process, hog manure contain 0.1% glucose started hydrogen production 3-6h earlier and ended 96h later than that only contain 0.1% glucose(contrast group); hydrogen productivity were 10.7 times than contrast group, hydrogen production rate of hog manure was higher than contrast group also; the highest rate of hog manure and contrast group were 34.72 mL.h"1.L1and 3.47mL.h’1.L1 respectively; the average rate were 24.4 mL.lf’.L1 and 1.5 mL.h^.L1 respectively. TCOD remove rate study showed that batch and continuous process were 95.8% and 80% respectively, as well as hydrogen conversion efficiency of two group were 315mL/gTCOD and 300mL/gTCOD respectively. Study on pH value change regulation in batch process showed that pH value was more stable in hog manure substrate , and pH value of hog manure dropped from 6.5 to 5.0 , however, pH value of contrast group dropped from 7.5 to 3.98. This showed that hog manure hog manure had the ability of pH equilibrium. Effect of the dominate parameter of continuous process dilution ratio on hydrogen production rate, pH value of hydrogen production system and TCOD remove ratio were determined in this paper,更多还原