规模化养猪场沼气发电工程实例分析

沼气发电不仅可以解决规模化养猪场畜禽污染,还可生产清洁能源,是发展可持续绿色循环农业的重要途径。以福建省福清市某规模化养猪场为例,介绍沼气产生工艺、沼气发电模式、注意问题及效益情况,为规模化养殖场沼气发电模式推广提供依据。     

能源环保型沼气工程在规模猪场排泄物治理中的应用

主要介绍了畜禽养殖场排泄物治理模式——能源环保型沼气工程在义乌某大型生猪养殖公司排泄物治理中的应用,详细介绍了该养殖场中的沼气工程的工艺路线、处理能力、工程规模、沼气发电以及工程调试运行情况。     

农村养殖场开展纯沼气发电的必备条件分析

农村养殖场开展纯沼气发电主要是提高沼气综合利用率及沼气工程经济效益。养殖场纯沼气发电开展得好不好,直接影响推广进度及效益。对养殖场开展纯沼气发电必备条件作简要分析介绍,为各地推广提供参考。     

我国生物质燃料乙醇示范工程的全生命周期评价

目前,我国甜高粱、木薯等"非粮"燃料乙醇正处于规模化推广的前期论证阶段,亟需对其进行全面深入的可行性分析.文章基于生命周期评价原理,结合国内4家燃料乙醇生产企业的示范工程,对其全生命周期过程的能源消耗、环境影响和经济成本提供定量的评价结果,为评价、对比"非粮"乙醇和"粮食基"乙醇提供科学、权威的数据,填补了这一方面国内研究领域的空白.评价结果表明,发展甜高粱和木薯等非粮乙醇是可行的,与玉米乙醇相比具有较强的优势.     

大中型沼气工程生命周期能效评价

基于生命周期评价理论,对山东某沼气工程进行了能效评价。研究得出,该沼气工程生命周期总能耗(折合标准煤)为561 471.47 kg/a(11.54 kg/GJ),其中,化石能耗占96.62%;节能量为1 100 271.42 kg/a;生命周期综合能源利用率为61.82%;生命周期新水耗量为26 552.56 m3/a。利用Sima Pro 8.0.2软件,采用生态指数法分析得出,该沼气工程生命周期产生的环境影响为364.303 3 k Pt/a(7.480 5 Pt/GJ);通过情景分析得出,沼气工程的环境损害减弱能力为191.805 2 k Pt/a(34.49%)。针对该沼气工程存在的一些问题,提出了开发沼液综合利用技术等建议,为提高沼气工程能效、减少环境损害提供理论参考。     

规模养殖场沼气工程基本情况调查

调查了我省部分大中型养殖场的基本情况,养殖场粪便污水的处理及利用现状,沼气工程在规模养殖场中的应用现状,以及沼气工程的应用前景等;并对利用沼气工程处理养殖场禽畜粪便的下一步推广工作提出了若干建议。     

沼气综合利用与生态农业建设

随着沼气技术的不断发展，农村沼气已不仅仅是为解决用户的生活用能，更主要的是搞好沼气综合利用，发展生态农业，以实现经济效益、社会效益和生态效益三者的有机统一。近几年来，新余市从实际出发，不断开发沼气、沼液、沼渣“三沼”的综合利用，建立了以“猪—沼—稻”、“猪—沼—菜”、“猪—沼—果”、“猪—沼—棉”以及“猪—沼—鱼”等为主的以沼气为纽带与种植业、养殖业有机结合的沼气工程生态农业模式，实现了物质循环和能量转化的良性循环，改善了农业生态环境，极大地促进了生态农业建设。1沼气综合利用和生态农业的含义及其…     

改善生态环境 促进农业可持续发展——瑞金市沼气生态农业工程建设的调查

沼气生态农业建设,是以沼气建设为中心,“上”联养殖业的高效快速发展,“下”促种植业的高产优质高效,“中”实现村容村貌的大改观,维护生态平衡,防止水土流失的“猪—沼—果”、“猪—沼—粮”、“猪—沼—蔗”、“猪—沼—菜”、“猪—沼—鱼”、“猪—沼—粮”、“猪—沼—烟”、“猪—沼—猪”八大模式化工程建设。近年来,瑞金市经过全市上下的共同努力,沼气生态农业工程建设取得了可喜的成绩,受到了各级领导和专家的高度赞扬。截至目前,全市有生态农业示范户8900户,拥有沼气池16700口。通过推广上述八种模式的综合利用,实现了受益农户…     

利用能值方法评价沼气工程性能——山东淄博案例分析

运用能值分析方法对山东省淄博市畜禽养殖场沼气工程和秸秆发酵沼气工程的投入和产出进行了计算和分析,结果显示:畜禽养殖场沼气工程的生态经济价值为2.38×105$/a,秸秆沼气工程为4.07×105$/a,两种沼气工程均具有很高的生态经济价值。通过能值指标综合对比,评价了淄博市两类沼气工程的效益和可持续发展能力,对比结果表明:畜禽养殖场沼气工程购入能值比率、能值投资率为秸秆沼气工程的0.3倍和0.17倍,自然能值与购入能值比、能值产出率和能值自给率分别是秸秆沼气工程的5.78倍、1.77倍和1.7倍;废弃物处理率是秸秆沼气工程的1.7倍,环境负荷率为秸秆沼气工程的0.2倍;能值反馈率是秸秆沼气工程的52倍,可更新率是秸秆沼气工程的1.44倍,可持续发展指标是秸秆沼气工程的9.25倍。     

武汉东西湖区养殖场固废循环经济工程技术设计

根据武汉市东西湖区养殖场实际情况,规划设计了一整套以沼气生产为纽带的循环经济工程技术模式,分析评估了养殖业固废处理循环经济实施的经济效益和环境社会效益.该模式以"暗河式大型联合沼气生产技术"为基础,将畜禽废弃物经过一系列的生物厌氧发酵产生沼气;沼渣、沼液结合好氧堆肥保温设施生产优质有机肥料;以现代化污水处理系统和人工湿地生态化处理沼液和养殖场废水,达到中水回用的标准;湿地种植饲料植物.在彻底消除畜禽养殖废弃物产生的环境污染的同时,实现养殖场循环经济生产模式的正常运作与发展.研究设计结果对其它地区实施养殖业固废处理循环经济模式具有一定借鉴意义.     

基于外部性收益的畜禽养殖场沼气工程补贴模式分析

以我国北方某沼气工程为例,按照业主自筹全部资金、2009年国家建设补贴标准和工程实际投资3种建设投资方式,对其现有经济性进行了分析,并提出了以外部性收益为依据对沼气工程进行补贴的两种模式。结果表明,外部性收益与沼气工程运行效果和沼气产量有直接关系,依据外部性收益对沼气工程进行补贴,可以显著提高沼气工程的经济效益,推动规模化养殖场沼气工程正常运行和发展。综合沼气工程投资者和社会利益考虑,业主自筹全部建设资金,按照工程实际运行的外部性收益给予补贴,既可保障工程的正常运营,又符合整体经济性。     

An Application of Solar Energy Storage in the Gas: Solar Heated Biogas Plants

Abstract

Temperature is an important factor that may affect the performance of anaerobic digestion. Therefore, biogas plants without heating system work only in warmer regions for the whole year. In regions with extreme temperature variations, for instance in Turkey, the biogas plant should be built with heating system. One of the methods is to use solar energy to increase the reactor temperature. In this study, solar heated biogas plants were reviewed. Furthermore, the optimization of insulation thicknesses and solar energy systems for 5 m³ biogas reactor were carried out for two different cities for three different climatic zones in Turkey. Based on the obtained results, the ratio of annually produced biogas used for reactor heating was calculated for each city, with and without solar heating system. Obtained results indicate that the biogas consumption for reactor heating is decreased by approximately 19% for average of six cities when solar heating system is used. This means that available biogas potential would be increased.     

Evaluation of methane production from maize silage by harvest of different plant portions

Biogas production is mainly based on the anaerobic digestion of cereals silages and maize silage is the most utilized. Regarding biogas production, the most important portion of the plant is the ear. The corn ear, due to high starch content, is characterized by a higher biogas production compared to the silage of the whole plant.In this paper, we present the results of experimental field tests carried out in Northern Italy that aim to evaluate the anaerobic methane potential (BMP) of different portions of ensiled maize hybrids. The BMP production is evaluated considering the possibility of harvesting and ensiling: the whole plant; the plant cut at 75 cm of height; the ear only; the plant without the ear. For the different solutions, the results are reported as specific BMP and as average biogas production achievable per hectare. The methane production by harvesting and ensiling the whole plant (10,212 and 10,605 m³ ha⁻¹, for maize class 600 and 700, respectively) is higher than the ones achievable by the other plant portions (7961 and 7707 m³ ha⁻¹, from the ear; 9523 and 9784 m³ ha⁻¹, from the plant cut at 75 cm; 3328 and 3554 m³ ha⁻¹, from the plant without the ear, for maize class 600 and 700, respectively). The harvest of the whole plant, although it is the most productive solution, could not be the best solution under an economic and environmental point of view. Harvesting only the ear can be interesting considering the new Italian subsidy framework and for the biogas plants fed by biomass transported over long distances.     

How to report biogas production when monitoring small-scale digesters in field

The aim of this research was to evaluate the error originated when biogas production from field monitoring digesters, influenced by the diurnal temperature cycle, was normalized to standard conditions for pressure and temperature (273.15 K and 100 kPa) from local conditions. The biogas production data is often reported without indicating if done under local conditions, whether these conditions have been standardized and, if they have actually been standardized, the standard temperature and pressure is not indicated. In this research ambient and biogas temperature, as well as biogas production were monitored with a 30 min frequency during three consecutive days, in three different tubular digesters. Normalization was realized using the high frequency data collected as reference values, and also using daily biogas production with mean daily biogas, ambient and nearby meteorological station temperatures. The outcome of this research shows that normalization of biogas production can be obtained using daily biogas production and the daily mean ambient temperature with an overestimation by no more than 1.5%, in comparison to the normalization achieved by using high frequency data from biogas temperature and production. Using mean daily ambient temperature or mean daily biogas temperature results in the same overestimation, while using mean daily ambient temperature from a nearby airport weather station pushes the overestimation up to 2.7%. So, if ambient temperature and altitude is identified, biogas production reported in local conditions can be normalized.     

Photobiostimulation of anaerobic digestion by laser irradiation and photocatalytic effects of trace metals and nanomaterials on biogas production

Biogas generation from the latent energy in biomass is one of the most attractive renewable energy sources. This can be attributed to the environmental friendly nature of the process and its less energy requirements. This article reviews the anaerobic digestion of biomass (livestock manure and crop residues) for biogas and methane production as a source of renewable energy. Furthermore, this study investigates the enhancement of biogas and methane production using light and laser radiations. The laser radiation accelerates bacterial division and growth, where this process is termed as “photobiostimulation.” Additionally, laser radiation photoactivates the inactive enzymes. The results of this literature review showed that the irradiation of methanogenic bacteria with laser sources increased the biogas production by one and a half fold the traditional method of biogas production. The simultaneous irradiation of both nanomaterials and methanogenic bacteria using laser radiation increased the biogas volume by twofolds the biogas volume resulted from the traditional method of biogas production.     

户用沼气池对农村家庭能源消费的影响--以江苏省涟水县为例

户用沼气池建设不但改变了农村家庭能源消费结构，还带动了农村养殖业、种植业的发展。通过对江苏省涟水县农村家庭能源消费和沼气池使用等相关问题的入户调查，定量研究了户用沼气池建设所产生的影响。证明户用沼气池的使用能提高家庭能源利用效率，减少能源消费量和化肥的使用量，有利于农作物秸秆的还田，提高农户的生活质量。     

Numerical modeling of SOFCs operating on biogas from biodigesters

In this study, numerical predictions of SOFCs performance operating on biogas are performed in order to evaluate the potential use of biogas produced from different organic sources processed in biodigesters as the fuel for SOFCs. The SOFC performance is predicted numerically by using a fully three-dimensional non-commercial CFD code called DREAM-SOFC. The analysis mainly focuses on the effect of biogas composition on the fuel cell performance. Different biogas compositions are used as the fuel supplied to the SOFC and the concentration of the species in the biogas are those measured by means of a gas chromatography system of the biogas produced in biodigesters installed at University of Guanajuato. Particularly, the biogas produced from water lily and cactus was evaluated as potential fuel for SOFCs. It was observed that the SOFC performance is higher when biogas from water lily is supplied to the SOFC when compared with biogas from cactus.     

施用沼肥对保护地土壤微生物群落影响的研究

以等有机质含量的猪粪、沼渣为基肥,以等量N,P,K的化肥和沼液为追肥,采用二裂式区组设计的方法,研究了沼肥、猪粪、化肥等不同施肥组合对设施土壤微生物多样性指数动态变化的影响.结果表明:在番茄苗期和开花期,土壤微生物多样性指数较高,在坐果期最低.与施用猪粪、化肥相比,施用沼渣、沼液有利于土壤中多种微生物的均衡生长,有利于土壤微生物种群的均匀分布.     

Experimental and computational study on the enhancement of engine characteristics by hydrogen enrichment in a biogas fuelled spark ignition engine

Limitations on the upgradation of biogas to biomethane in terms of cost effectiveness and technology maturity levels for stationary power generation purpose in rural applications have redirected the research focus towards possibilities for enhancement of biogas fuel quality by blending with superior quality fuels. In this work, the effect of hydrogen enrichment on performance, combustion and emission characteristics of a single-cylinder, four-stroke, water-cooled, biogas fuelled spark-ignition engine operated at the compression ratio of 10:1 and 1500 rpm has been evaluated using experimental and computational (CFD) studies. The percentage share of hydrogen in the inducted biogas fuel mixture was increased from 0 to 30%, and engine characteristics with pure methane fuel was considered as a baseline for comparative analysis. The CFD model is developed in Converge CFD software for a better understanding on combustion phenomenon and is validated with experimental data. In addition, the percentage share of hydrogen enrichment which would serve as a compromise between biogas upgradation cost and engine characteristics is also identified. The results of study indicated an enhancement in combustion characteristics (peak in-cylinder pressure increased; COV_IMEP reduced from 9.87% to 1.66%; flame initiation and combustion durations reduced) and emission characteristics (hydrocarbon emissions reduced, and NOx emissions increased but still lower than pure methane) with increase in hydrogen share from 0 to 30% in biogas fuelled SI engine. Flame propagation speed increased and combustion duration reduced with hydrogen supplementation and the same was evident from the results of the CFD model. Performance of the engine increased with increase in hydrogen share up to 20% and further increment in hydrogen share degraded the performance, owing to heat losses and the enhancement in combustion characteristics were relatively small. Overall, it was found that 20% blending of hydrogen in the inducted biogas fuel mixture will be effective in enhancing the engine characteristics of biogas fuelled engines for stationary power generation applications and it holds a good compromise between biogas upgradation cost and engine performance.     

中外沼气产业政策浅析

本文在分析我国沼气产业发展现状的基础上,梳理了现有沼气产业政策及其在产业链各环节上的布局,并与沼气产业发达的欧盟地区的政策进行对比。分析结果显示,我国颁布法律鼓励发展沼气,制定发展规划,提出沼气的阶段性发展目标,出台经济扶持政策补贴原料利用、工程建设及终端应用,制定国家及行业标准规范产业发展,立法及扶持政策推动我国沼气跨入产业化发展阶段。但与欧盟地区的产品补贴力度大、范围广,减免税政形式多样,标准化和质量检验体系完善等特点的产业政策相比,我国沼气政策仍存在终端产品补贴力度不足、工程及装备标准认证体系滞后、市场监管及运营粗放等问题。基于此,提出转变沼气工程建设及产品补贴方式、加强沼气产业减税政策的执行力度、完善和统一沼气产业规范标准体系等建议。