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云南省沼气及其综合利用发展预测与分析 总被引:1,自引:0,他引:1
云南省气候适宜,农村有机废弃物丰富,是以展沼气的理想区域.沼气综合利用前景广阔,沼气发酵系统与农业相结合,能使农业的发展容能源、经济、社会和生态效益为一体,有力地促进农村经济的发展,是我国农业奔小康的理想途径之一.针对云南省沼气发展现状,在对沼气及其综合利用发展预测与分析的基础上,对云南省发展沼气提出一些看法 相似文献
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发展沼气生态农业可以实现资源的综合利用,带来经济效益与生态效益,同时解决我国农村地区能源短缺和环境污染问题。明确沼气系统内部的物质能量转化利用情况,可为沼气农业系统优化和效益提升提供科学依据。提出基于生命周期的户用沼气系统可用能核算方法,并以全国生态农业示范县——广西恭城瑶族自治县为例,核算了该县典型户用沼气系统建设、运行和利用单元投入产出的可用能流,分析了整个系统的可用能转化与利用效率。结果表明:系统的可用能投入为(1.06×108)kJ/a,可用能产出为(5.00×107)kJ/a,主要产出形式为沼渣;可用能转化率为48.82%,利用率为21.60%,其中沼气利用效率最高;系统产生的环境排放为(3.42×105)kJ/a,主要形式为系统利用单元沼气燃烧产生的CO2。由此可见,沼气生态农业可通过增加转化环节实现农业废弃物的再利用,系统可用能效率具备极大的提升空间,系统可持续性有待加强。可以考虑从改进工艺技术和改善发酵环境两方面提高户用沼气系统能量转化的能力,通过沼渣沼液综合利用技术方面的创新提高户用沼气系统的可用能利用效率。生命周期可用能核算方法可以更全面的反映系统的能量利用效率,便于诊断薄弱环节,为系统优化提供依据。 相似文献
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厌氧消化法处理畜禽粪的研究 总被引:4,自引:0,他引:4
本文报导了2个沼气工程的概况。其一是上海跃进农场的装置128m3的上流式厌氧污泥床(UASB),该装置于1985年建成,已正常运行8年。用于处理2万羽鸡的粪水,20~24℃发酵,共产气45万m3。平均产气率1.35m3/m3.d。COD去除率88%。产生的沼气供应120户居民使用。其二是上海星火农场沼气站,该站为处理2700头奶牛的粪便,于1991年建成了2700m3上流式全混合型厌氧消化装置,日处理牛粪便80吨,鸡粪20吨,25~31℃发酵。至1996年底,共产气360万m3,供应了3000户职工及10个集体单位使用。发酵残留物全部进行了综合利用,不但净化了环境而且创造了较好的经济效益。2个工程长期稳定运行的结果表明,沼气工程的工艺设计先进,设备配套齐全,可为全国畜禽粪的处理提供供鉴。 相似文献
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针对我国大中型沼气工程所存在的系统热量利用不合理等问题,以河南省南阳市内乡牧原日产10 000 m3粪污资源化处理沼气示范工程为例,对沼气工程沼液余热回收工艺进行研究,分析其系统热力学性能及经济性能。计算结果表明,秋冬季节该沼气工程热能需求量约为7.77×104~1.09×105MJ,其中,99.5%用于系统增温。同时,对比分析了采用传统的沼气锅炉供热、沼气锅炉与系统余热回收联用供热两种供热方式的系统能耗后发现,沼气锅炉与余热回收联用可以大大降低沼气锅炉用气量,仅为传统工艺耗气量的20%~35%,可使更多的沼气用于发电。此外,还对系统进行了热力学评价,沼气锅炉与系统余热回收联用可使系统总■效率提升8%~13%,秋冬季节利用余热回收可以节省沼气、增加发电量,为11 940~15 525 k W·h,每天可产生经济效益为5 970~7 762元。 相似文献
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Biogas produced from organic wastes contains energetically usable methane and unavoidable amount of carbon dioxide. The exploitation of whole biogas energy is locally limited and utilization of the natural gas transport system requires CO2 removal or its conversion to methane. The biological conversion of CO2 and hydrogen to methane is well known reaction without the demand of high pressure and temperature and is carried out by hydrogenotrophic methanogens. Reducing equivalents to the biotransformation of carbon dioxide from biogas or other resources to biomethane can be supplied by external hydrogen. Discontinuous electricity production from wind and solar energy combined with fluctuating utilization cause serious storage problems that can be solved by power-to-gas strategy representing the production of storable hydrogen via the electrolysis of water. The possibility of subsequent repowering of the energy of hydrogen to the easily utilizable and transportable form is a biological conversion with CO2 to biomethane. Biomethanization of CO2 can take place directly in anaerobic digesters fed with organic substrates or in separate bioreactors. The major bottleneck in the process is gas-liquid mass transfer of H2 and the method of the effective input of hydrogen into the system. There are many studies with different bioreactors arrangements and a way of enrichment of hydrogenotrophic methanogens, but the system still has to be optimized for a higher efficiency. The aim of the paper is to gather and critically assess the state of a research and experience from laboratory, pilot and operational applications of carbon dioxide bioconversion and highlight further perspective fields of research. 相似文献
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《Critical reviews in biotechnology》2013,33(4):327-348
Whey, the liquid remaining after milk fat and casein have been separated from whole milk, is one of the major disposal problems of the dairy industry, and demands simple and economical solutions. In view of the fast developments in biotechnological techniques, alternatives of treating whey by transforming lactose present in it to value added products have been actively explored. Whey can be used directly as a substrate for the growth of different microorganisms to obtain various products such as ethanol, single-cell protein, enzymes, lactic acid, citric acid, biogas and so on. In this review, a comprehensive and illustrative survey is made to elaborate the various biotechnological innovations/techniques applied for the effective utilization of whey for the production of different bioproducts. 相似文献
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The aims of this work were to determine the specific biogas yields of steam-exploded sugarcane straw and bagasse as well as to estimate their energy potential under Brazilian conditions. Steam-explosion was carried out under different time and temperature conditions. The specific biogas yields were analyzed in batch-tests according to VDI 4630.Results have shown that steam-explosion pre-treatment increased the specific biogas yields of straw and bagasse significantly compared to the untreated material. The utilization of these by-products can contribute to 5% of the total energy consumption and thereby higher energy independence in Brazil. Further efforts in defining the optimum pretreatment conditions with steam-explosion as well as implementing this technology in large scale plants should be made. 相似文献
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沼液的定价方法及其应用效果研究 总被引:4,自引:0,他引:4
为了探索沼液的商品化,采用养分含量定价和应用效果定价2种方法确定了沼液的价格,并分析了沼液施用后对土壤基本理化性状的影响作用。结果发现:采用养分含量定价法得到的沼液价格为78.12元/m3,采用沼液应用效果定价法得到的沼液的价格为111.4元/ m3;沼液的实际应用价值要明显高于其养分含量的市场价;沼液施用后可降低土壤容重,增加土壤孔隙度,增加土壤有机质、土壤全氮、土壤有效磷及有效钾含量,有利于土壤肥力的保持。 相似文献
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Integrated biogas upgrading and hydrogen utilization in an anaerobic reactor containing enriched hydrogenotrophic methanogenic culture 总被引:1,自引:0,他引:1
Biogas produced by anaerobic digestion, is mainly used in a gas motor for heat and electricity production. However, after removal of CO2, biogas can be upgraded to natural gas quality, giving more utilization possibilities, such as utilization as autogas, or distant utilization by using the existing natural gas grid. The current study presents a new biological method for biogas upgrading in a separate biogas reactor, containing enriched hydrogenotrophic methanogens and fed with biogas and hydrogen. Both mesophilic‐ and thermophilic anaerobic cultures were enriched to convert CO2 to CH4 by addition of H2. Enrichment at thermophilic temperature (55°C) resulted in CO2 and H2 bioconversion rate of 320 mL CH4/(gVSS h), which was more than 60% higher than that under mesophilic temperature (37°C). Different dominant species were found at mesophilic‐ and thermophilic‐enriched cultures, as revealed by PCR–DGGE. Nonetheless, they all belonged to the order Methanobacteriales, which can mediate hydrogenotrophic methanogenesis. Biogas upgrading was then tested in a thermophilic anaerobic reactor under various operation conditions. By continuous addition of hydrogen in the biogas reactor, high degree of biogas upgrading was achieved. The produced biogas had a CH4 content, around 95% at steady‐state, at gas (mixture of biogas and hydrogen) injection rate of 6 L/(L day). The increase of gas injection rate to 12 L/(L day) resulted in the decrease of CH4 content to around 90%. Further study showed that by decreasing the gas–liquid mass transfer by increasing the stirring speed of the mixture the CH4 content was increased to around 95%. Finally, the CH4 content around 90% was achieved in this study with the gas injection rate as high as 24 L/(L day). Biotechnol. Bioeng. 2012; 109: 2729–2736. © 2012 Wiley Periodicals, Inc. 相似文献
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Weiland P 《Biodegradation》2000,11(6):415-421
Anaerobic treatment processes are especially suited for the utilization of wet organic wastes from agriculture and industry as well as for the organic part of source-separated household wastes. The anaerobic degradation is a very cost-effective method for treating biogenic wastes because the formed biogas can be used for heat and electricity production and the digester residues can be recycled to agriculture as a secondary fertilizer. The anaerobic technology will be used today also for the common treatment of wastes together with renewable energy crops in order to reduce the CO2-emissions according the Kyoto protocol. Various process types are applied in Germany which differ in material, reaction conditions and in the form of the used reactor systems. The widespread introduction of anaerobic digestion in Germany has shown that biogenic organic wastes are a valuable source for energy and nutrients. Anaerobic waste treatment is done today in approx. 850 biogas plants on small farm scale as well as on large industrial scale with the best beneficial and economic outcome. Due to some new environmental protection acts which promote the recycling of wastes and their utilization for renewable energy formation it can be expected that several hundreds new biogas plants will be built per year in Germany. For using the synergetic effects of a combined fermentation of wastes and energy crops new process types must be developed in order to optimize the substrate combinations and the process conditions for maximum biodegradation. 相似文献