德国沼气工程现状分析

介绍了德国沼气工程应用现状,包括沼气工程数量、地域分布情况、发电装机容量等。从发酵原料、发酵工艺、沼气净化、沼渣及沼液利用等方面对德国沼气技术进行了综合介绍。德国的沼气工程普遍采用混合原料进行发酵,德国政府很重视装机容量为150kW以下的小型沼气工程的建设,沼气被有效用于发电、供热,并入天然气网络等。通过加大政府扶持可再生能源的力度,鼓励全国广泛使用沼气,不仅可以使沼气运营商从中获得可观的经济效益,而且可以达到减少排放有机废物的目的,减少温室气体对环境的污染。     

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.     

红泥塑料气罩式沼气池的产气效果

红泥塑料具有良好的密封性能和热稳定性,耐老化,耐低温。目前,已较广泛地应用红泥塑料做沼气袋。为沼气发酵装置提供一种新型的有机材料。由于它吸收太阳能,提高池温的效果和气密性优于地埋式水泥沼气池,而且便于商品化生产,能够保证质量和降低成本,假如进一步提高质量,改进工艺,将会促进我国农村沼气建设的发展。红泥塑料气罩式沼气池根据目前农村条件,可采用半连续湿发酵工艺及批量投料干发酵工艺。湿发酵一般以人畜粪便作原料,干物质含量6—10%,投料20天后,每隔五天进出料一次,加料量为发酵料液总量的     

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     

论太阳能与车库型干法沼气工程的完美结合

结合传统太阳能热利用工程与德国车库型干法沼气工程,设计出利用太阳能为沼气工程增温的太阳能沼气系统,并以高寒地区哈尔滨为例,对系统进行了初步估算。结果表明,车库型干法沼气工程适合与太阳能热利用工程实现一体化,结合太阳能热利用工程后该系统年可节约标煤159.6t,同时为系统的稳定运行提供了能源保障。     

德国典型沼气发电技术及其借鉴

以5处沼气发电工程为例,介绍了德国典型的沼气发电技术,其普遍采用"混合厌氧发酵、沼气发电上网、余热回收利用、沼渣沼液施肥、全程自动化控制"的技术模式,通过该模式的实施,最终实现发酵原料的全方位综合利用;并通过电、热以及沼渣沼液的外售给工程运行带来收益,最终实现市场化运行。通过对此次考察相关情况的介绍与总结,以期为我国大中型沼气工程的发展提供一些借鉴。     

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。     

3MW集中式热电肥联产沼气工程设计与建设

山东民和牧业股份有限公司利用所属23家养殖场的鸡粪和污水作为沼气发酵原料,投资建设大型畜禽养殖场集中式沼气发电工程.原料经水解除砂工艺将鸡粪中的砂砾除去,保证发酵效率;采用中温(38 ℃)发酵工艺,产沼气30 000 m3/d;采用高效率低运行成本的生物脱硫工艺,将沼气中的H2S含量降至200×10-6以下;经净化的沼气在双膜干式贮气柜中贮存,供给热电联产的发电机组使用.发电量60 000 kWh/d,机组余热用于冬季发酵系统自身增温;发酵后的沼液用作周围葡萄、苹果及玉米地的有机肥料.项目实现了温室气体减排84882tCO2当量.文章介绍了该沼气发电工程的工艺特点和技术要点,为同类型沼气发电工程设计和建设提供参考.     

福建省沼气工程技术发展现状

叙述了福建省沼气工程技术研究发展状况、福建省沼气工程、沼气池型研究、大中型养殖场污水治理及综合利用研究等方面的主要成就,提出了今后值得关注的研究方向,如：畜牧场污水治理新工艺、新设备研究、干发酵技术及设备研究、沼气可控生态温室和有机无土栽培研究等。     

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。     

沼气发酵猪粪管理系统对温室气体排放的影响

基于生命周期清单分析以及清洁发展机制,引入"碳足迹"概念,对我国散养猪以及规模化养猪场引入沼气发酵系统后猪粪管理系统温室气体排放及减排进行了估算。农户散养猪粪处理系统中,12 m3沼气池厌氧发酵过程碳足迹为223.40 kg CO2e/a,沼气代替原煤燃烧减少444.33 kg CO2e/a温室气体,沼气发酵净减少220.93 kg CO2e/a温室气体,我国散养生猪产生的猪粪以此沼气池发酵可减少温室气体20 984.62 Gg CO2e/a;分析运行规模约1 000 m3大型沼气工程的碳足迹,保守估计为2 835.32 t CO2e/a,运行沼气工程替代煤炭以及减少猪粪排放的温室气体共约2 914.23 t CO2e/a,故沼气工程年减少温室气体78.91 t CO2e,该项目共可减排1 578.20 t CO2e。在猪粪管理系统中采用沼气发酵系统可以更好地促进温室气体减排的进行。     

分散原料沼气集中供气运行分析

我国规模化沼气工程存在原料单一、产气率低、装备落后等技术瓶颈,西南地区沼气原料来源分散、成分复杂,因此需要开发新的多种原料混合发酵的新模式来提高沼气工程厌氧消化效率。本工程通过全混式厌氧发酵两级工艺共同厌氧消化如秸秆和畜禽粪便等分散原料,形成新的沼气和发酵剩余物利用模式。结果表明,在30 d稳定运行期间,600 m³厌氧发酵罐每天可消纳猪粪7.9 t、浓污水8.2 t及农作物秸秆0.2 t,日产气量为900 m³,混合原料发酵的容积产气率达1.5 m³/(m³∙d)。     

Intracellular disintegration by shockwave pretreatment accelerates “dry fermentation”

Dry fermentation refers to the process of anaerobic digestion that does not take place in a mixable liquid environment but in stacks loaded into airtight chambers. Since it is difficult for anaerobic consortia to decompose biomass without operating fluid, the process of dry fermentation is time consuming and considered technically inefficient. However, the construction costs of such biogas plants are significantly lower in comparison to conventional continuous technologies. Shockwave pretreatment is a modern method of intracellular disintegration that occurs purely on the basis of physical forces. It was confirmed for the first time that shockwaves are capable of accelerating methanogenesis, even in technologies that do not utilise a process liquid. This finding opens up new opportunities with regards to the processing of feedstock such as solid biowaste.     

What type of digester configurations should be employed to produce biomethane from grass silage?

Grass is an excellent energy crop; it may be classified as a high yielding, low energy input, perennial crop. Over 90% of Irish agricultural land is under grass; thus farmers are familiar with, and comfortable with, this crop as opposed to a “new energy crop” such as Miscanthus. Of issue therefore is not the crop, but the methodology of generating energy from the crop. Numerous farmers across Europe (in particular Germany and Austria) use grass silage as a feedstock for biogas production; in a number of cases the produced biogas is scrubbed to biomethane and used as a transport fuel or injected into the natural gas grid. Many Irish farmers are considering converting from conventional farming such as beef production to grass biomethane production. Numerous technologies and combinations of such technologies are available; from one-stage batch dry systems to two-stage wet continuous systems; from one-stage continuous wet systems to two-stage systems incorporating a batch dry reactor coupled with a second stage high-rate reactor. This paper reviews work carried out both in the scientific literature and in practice at commercial scale.     

Use of waste for heat,electricity and transport—Challenges when performing energy system analysis

This paper presents a comparative energy system analysis of different technologies utilising organic waste for heat and power production as well as fuel for transport. Technologies included in the analysis are second-generation biofuel production, gasification, fermentation (biogas production) and improved incineration. It is argued that energy technologies should be assessed together with the energy systems of which they form part and influence. The energy system analysis is performed by use of the EnergyPLAN model, which simulates the Danish energy system hour by hour. The analysis shows that most fossil fuel is saved by gasifying the organic waste and using the syngas for combined heat and power production. On the other hand, least greenhouse gases are emitted if biogas is produced from organic waste and used for combined heat and power production; assuming that the use of organic waste for biogas production facilitates the use of manure for biogas production. The technology which provides the cheapest CO₂ reduction is gasification of waste with the subsequent conversion of gas into transport fuel.     

Household biogas use in rural China: A study of opportunities and constraints

As a renewable energy, biogas is not only an important part of the development of rural new energy, but also an important aspect of sustainable development in China. The development process and present status of household biogas, specifically the opportunities and constraints of household biogas in rural China, are discussed in this paper. Only about 19% of the biogas potential has been utilized in rural China. There are several opportunities for household biogas development in rural China, including the problem of rural household energy consumption, the availability of biogas fermentation materials, national financial subsidies, legal and international clean development mechanisms. Also, more research needs to be done in straw fermentation and cold fermentation technology. Training should be conducted to raise the level of biogas customers in comprehensive biogas utilization. Measures should be taken to improve the follow-up services and management of biogas plants. The information presented in this paper will be helpful not only to the sustainable development of household biogas in rural China, but also to the development of biogas in similar countries around the world.     

Anaerobic fermentation technology increases biomass energy use efficiency in crop residue utilization and biogas production

A biomass energy utilization project (Corn stalk→Cattle→Cattle dung→Biogas digester→Biogas/Digester residues→Soil) was conducted in a typical temperate agro-village of China from 2005 to 2010. The present study focused on two key approaches of the ecological loop: (1) increasing corn stalk use efficiency by improving anaerobic fermentation technology; and (2) enhancing biogas productivity by optimizing fermentation conditions. Our results showed that crude protein and fat of corn stalks significantly increased, while crude fiber content and pH decreased considerably during anaerobic fermentation. The cattle digestion rate, forage consumption and increases in cattle weight were higher in cattle fed fermented corn stalks than in those fed non-fermented corn stalks. The rate of biogas production was higher (78.4%) by using cattle dung as a substrate than using crop residues. Heat preservation measures effectively enhanced the biogas production rate (12.3%). In 2005, only two cattle were fed in this village, with only 1.1% corn stalk utilized as forage. No more than three biogas digesters existed, and the proportion of biogas energy used in total household fuel was only 1.7%. At the end of the 5-year experiment, the number of cattle capita reached 169 with 78.9% corn stalk used as forage. Biogas digesters increased to 130, and the proportion of biogas energy used in total household fuel was up to 42.3%. A significant positive correlation was noted between the increasing rate of farmers’ incomes and the proportion of corn stalks used as forage. Available nutrients were higher in fermented cattle dung than in fresh cattle dung. Our findings clearly suggest that anaerobic fermentation technology is important in enhancing crop residue use efficiency, biogas productivity and soil fertility. Fermentation technology may help reduce the use of fossil fuels and improve the environment in rural areas.     

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。     

大型热电肥联产沼气发电工程分析

从工艺流程、技术参数、运行状况以及效益分析等方面对现今国内畜禽场规模最大的沼气发电工程进行技术分析。运行表明,通过全混式厌氧发酵（CSTR）两级工艺,纯鸡粪进行厌氧发酵沼气发电是确实可行的;该工程的成功既解决了鸡粪污染,又产生了巨大的经济社会效益,对实现畜禽粪便综合利用具有良好的示范效果,并可为同类型沼气发电工程设计和建设提供参考。