家用沼气池基本知识讲座 第三讲 沼气发酵与投料技术

沼气池为沼气发酵提供了密闭的发酵环境,要制取沼气还要依赖于沼气发酵工艺与投料技术,才能完成沼气生产的全过程。第一节沼气发酵与工艺参数沼气发酵是由沼气微生物在厌氧环境条件下分解有机物质生成沼气的生命活动的全过程。沼气菌正常生活需要一定的环境条件,为了取得较高的产气量,创造适宜的沼气发酵环境所采取的技术与方法,称为沼气发酵工艺。沼气发酵工艺又靠有关技术参数。所以农家摘沼气池只有熟悉掌握发酵工艺与技术参数,才     

新建沼气池稻草产气的简要操作法

介绍了新建沼气池用稻草作发酵原料产沼气的操作方法.针对农村沼气用户缺少发酵原料,用“绿秸灵”加碳酸氢铵等处理稻草,替代人畜粪便作为沼气发酵原料.稻草产沼气技术操作简单、原料广泛、产气充分、技术成熟,为发酵原料缺乏的沼气用户提供了一条可靠且有效的解决途径.     

多元原料混合发酵制备沼气技术研究进展

目前,我国沼气的发酵原料主要是禽畜粪便和农作物秸秆,随着厌氧发酵技术的发展,更多种类废弃物也逐步受到人们的关注。有机废弃物沼气化利用在我国生态文明建设中有着重大意义。论文综述了我国生物质资源,如禽畜粪便、农作物秸秆、农产品加工废弃物、市政有机废弃物和能源作物的特性和作为沼气发酵原料的优缺点,比较了这些原料的沼气生产潜力,探讨了混合原料发酵技术及重要的几种沼气发酵外源添加剂。     

家用沼气发酵工艺规程的通俗应用

为了使沼气用户比较容易掌握沼气发酵和管理使用技术,根据国家技术监督局发布的GB9958-88《农村家用沼气发酵工艺规程》技术要求和目前普遍推广的家用沼气池多为水压式以及常温发酵的条件,总结出如下通俗技术规程,以促进沼气技术的普及。     

城市垃圾的沼气发酵技术

从前,城市垃圾中的厨房垃圾都不作为沼气发酵的对象。日立集团开发了城市厨房垃圾为对象的沼气发酵技术,研制成回收能量的沼气装置。此装置的特点是:通过化学预处理、液化发酵、气化发酵,形成高速     

添加金属离子对沼气发酵及减硫影响的研究

目前的沼气脱硫技术基本上都是对沼气进行后期处理,鲜有文献报道从沼气发酵源头减少硫化氢生成。试验以马铃薯和红薯皮渣混合物为原料,添加氯化镍和氯化镁进行了厌氧发酵试验,考察金属离子对沼气发酵过程中减硫的影响。研究结果表明,氯化镍和氯化镁添加量为0~500mg/kg时可以促进沼气发酵的进行,并减少硫化氢的生成量,但添加量增大时会导致沼气中甲烷含量降低,甚至发酵停止。     

中德沼气工程比较

在考察中国和德国沼气工程现场及查阅大量文献报道的基础上,就中德沼气工程发展现状、政策法规、技术进展(包括发酵原料、发酵工艺、沼气净化、沼渣沼液利用以及沼气发电)等方面进行了比较,提出了中国农业废弃物沼气工程的差距以及改进的措施。     

中德沼气工程此较

在考察中国和德国沼气工程现场及查阅大量文献报道的基础上,就巾德沼气工程发展现状、政策法规、技术进展(包括发酵原料、发酵工艺、沼气净化、沼渣沼液利用以及沼气发电)等方面进行了比较,提出了中国农业废弃物沼气工程的差距以及改进的措施.     

我国沼气技术的利用现状与前景展望

通过分析常用几种生物质能资源的发酵技术来阐述了我国对沼气的利用现状,并对沼气技术存在的问题提出了解决办法,对沼气技术的前景进行了展望。     

浅谈沼气发酵

一前言沼气发酵又称厌氧消化,是在厌氧环境中微生物分解有机物最终生成沼气的过程,其产品是沼气和发酵残留物(高效的有机肥)。沼气发酵是生物质能转化最重要的技术之一,它不仅能有效处理有机废物,降低化学需氧量(COD),还有杀灭致病菌,减少蚊蝇孳生的功能。此外,沼气发酵作为废物处理的手段,不仅能耗省,还能产生优质的燃料沼气和肥料。     

酒精行业沼气、废渣锅炉混烧-发电循环技术的开发与分析

通过对连云港市酒精行业沼气、废渣锅炉混烧实践的论述,及其循环经济推广技术开发的分析、论证,在对废渣脱水和挤压成型技术进行攻关研究的基础上,提出了废渣和沼气混合燃烧需要解决的关键措施。经实践证明,该技术节能效果显著,促进了循环经济的发展。     

Biogas energy technology in Sudan

Biogas from biomass appears to have potential as an alternative energy in Sudan, which is potentially rich in biomass resources. This is an overview of some salient points and perspectives of biogas technology in Sudan. The current literature is reviewed regarding the ecological, social, cultural and economic impacts of biogas technology. Sudan is blessed with abundant solar, wind, hydro, and biomass resources. Results suggest that biogas technology must be encouraged, promoted, invested, implemented, and demonstrated, but especially for remote rural areas.     

我国农村沼气建设现状及发展对策

论述了目前我国农村沼气的发展现状和特点，指出农村沼气建设已进入了规模化发展的阶段，并取得了显著的经济、社会和生态等综合效益，同时针对农村沼气项目推广中出现的认识、技术、资金、管理等方面的问题，提出了相应的对策和建议。     

污水厌氧处理后的沼气发电及余热利用的实践

分析和介绍沼气回收综合利用的情况,将沼气回收脱硫预处理后用于发电和制冷,即将高品位能源用于发电,发电机组排放的低品位能源(烟气余热、热水余热)用于制冷,达到充分利用能源的目的,产生较好的经济效益和社会效益。     

Biogas upgrading technologies – Recent advances in membrane-based processes

This study reviews the major biogas upgrading technologies, with specific regard to recent progress in the field of membrane technology. More specifically, the objective of the present work is to provide the state-of-the-art of membrane-based processes for biogas upgrading, focusing primarily on the latest advances in membrane configurations/materials (e.g. for producing novel composite or mixed matrix membranes) and on hybrid technologies which integrate biogas upgrading with established membrane-based processes, such as the membrane bioreactor, membrane electrolysis or gas-liquid absorption. In order to demonstrate the potential of membrane technology for biogas upgrading in real field applications, the review also presents some cutting-edge biogas upgrading plants, located and operated in Europe and USA, and a brief summary of recent research studies (conducted during the last 5 years), which examine the economic feasibility of membrane-based technologies for biogas upgrading. Finally, challenges and future perspectives of applying membrane-based processes for biogas upgrading are discussed.     

Determinants for adoption decision of small scale biogas technology by rural households in Tigray,Ethiopia

The deployment of biogas energy as alternative energy source can have the potential to fill the gap in the energy needs of the rural community if it is effectively managed and appropriately utilized. Using a logistic regression analysis of cross sectional data, the driving forces for adoption decision of biogas technology by rural households in the Tigray region, Ethiopia, were examined. The study found that the factors that significantly affect biogas adoption decision of rural households were for the most part socio-demographic factors and access to basic infrastructures. Besides, some environmental, institutional and economic attributes were significantly associated with diffusion of biogas technology. From among the variables included in the model, age of household head, family size, level of education, cattle size owned, distance to firewood collection site, access to electricity, access to credit and access to all weather roads were found to positively affect biogas adoption decision of households. On the other hand, distance to the nearest market negatively affected the adoption decision of the households. Female headed households tend more to adopt the biogas technology as compared to their male counterparts. As socio-economic attributes of households and environmental factors are mostly varied contextually and spatially, the policy of biogas technology promotion should be tailored based on the principle of fit for the purpose instead of the existing unimodal approach for all settings.     

Socio-economic hurdles to widespread adoption of small-scale biogas digesters in Sub-Saharan Africa: A review

The unsustainable use of fossil fuels has led to increased awareness and widespread research on the accessibility of renewable energy resources such as biogas. Biogas is a methane rich gas that is produced by anaerobic fermentation of organic material. Despite its potential to replace biomass in Africa, where over 70% of the households use wood fuel and agricultural waste for cooking, biogas technology has not been adopted by Sub-Saharan African countries compared to their Asian counterparts. This paper examines the socioeconomic constraints to adoption of biogas in Sub-Saharan Africa and explores factors that could enhance adoption of the technology. These include standardization and quality control, as well as an approach of integrated farming using biogas and slurry. The article recommends mobilization of local and external funds to promote biogas, use of ready to use funds such as the Clean Development Mechanisms in overcoming the initial construction costs of biogas units, and formation of user and disseminator associations to reduce costs by joint procurement and linkage to finance. It further advocates the promotion of multiple uses of biogas for purposes other than cooking and lighting. It is expected that widespread adoption of the technology could lead to self-sufficiency in household energy provision for cooking. This would facilitate environmental management and economic development in Sub-Saharan Africa.     

Flexible power generation scenarios for biogas plants operated in Germany: impacts on economic viability and GHG emissions

Biogas plants enable power to be generated in a flexible way so that variable, renewable energy sources can be integrated into the energy system. In Germany, the Renewable Energy Sources Act promotes flexible power generation in biogas plants. Two existing biogas plants in flexible operation were analyzed with respect to economic viability and greenhouse gas (GHG) emissions to assess the feasibility of flexible operation. To do this, a biogas technology simulation model was developed to reproduce the technical design of both biogas plants and to link this design with twelve flexibilization scenarios. The evaluation of the economic viability is based on a discounting method of investment appraisal. For assessing the level of GHG emissions, the life cycle assessment method has been applied. The results show that the profitability of flexibilization is contingent upon premium payments promoting flexibility and direct sales resulting from a higher electrical efficiency of new or additionally installed combined heat and power units. Overall, with respect to profitability, the results of the flexible power generation scenarios are dependent upon the properties of the technical plant, such as its power generation and gas storage capacities. Relative GHG emissions from flexible biogas plants show significantly lower values than for referenced fossil gas–steam power stations. Among the various scenarios, the results reveal that the level of GHG emissions especially depends on the number of operating hours of the additional combined heat and power unit(s). The results of the analyzed biogas plants showed no direct correlation between GHG emissions and the economic benefits. Overall, a flexible power generation of biogas plants may improve the economic viability as well as result in lower GHG emissions in comparison with a conventional base load operation. © 2016 The Authors. International Journal of Energy Research published by John Wiley & Sons Ltd.     

基于LCA原理的国内典型沼气工程能效和经济评价

我国养殖场大中型沼气工程正处于产业化前期发展阶段,及时总结经验、发现问题,优化筛选出几种适宜于在全国大范围推广的沼气工艺模式,成为目前亟待解决的问题。基于生命周期评价原理,结合国内7个具有典型代表性的养殖场沼气工程,对其全生命周期过程的能源消耗、经济效益提供定量的评价,为对比、评价各种工艺模式的优劣提供科学、权威的数据,填补这一方面国内研究的空白。评价结果表明,内蒙古蒙牛"热电联产工业化生产"模式、北京蟹岛度假村"前店后园农游结合型"模式、浙江义乌顺旺养殖场"猪—沼—草—猪"生态养殖模式等沼气工程模式具有较强的综合优势,适宜在国内进行大范围推广。     

A review of the biogas industry in China

This article presents an overview of the development and future perspectives of the Chinese biogas industry. The development of the industry has the potential to improve the rural environment and produce significant amounts of sustainable energy for China. Barriers to the development are the relatively weak environmental policies, imperfect financial policies and lack of long-term follow-up services. The rapid economic development of China has also seen a development in the scales of biogas plants constructed. Although the technology has been improved, this review has identified problems in the construction and operation of Chinese biogas plants, particularly in the efficiency of household systems. All levels of China's government acknowledge this and recent biogas projects have more focus on quality and less on the quantity. The intention is to gradually introduce stricter environmental policies, to provide better service systems, improve the financial policies that support the construction and follow-up service of biogas projects, promote the use of standardized engineering equipment and materials and standards for plant construction and production. This will promote the development of biogas projects at various scales further, and reduce the dependency on fossil fuels and emissions of greenhouse gases.