广东省沼气资源潜力与养殖场沼气工程效益分析

文章介绍了广东省养殖场的沼气工艺流程,并利用广东省2017年统计年鉴的数据,评估计算了生猪、奶牛、肉牛、羊和鸡的粪尿量及其潜在的沼气资源量.评估结果表明:2016年广东省沼气资源量为24.37亿m3,若按沼气中含有50％的甲烷气体计,则折合甲烷12.19亿m3,约占广东省同年天然气消费量的7.3％.文章以广州市花都区大...     

Agricultural biogas plants in Poland: Investment process,economical and environmental aspects,biogas potential

The formal and legal requirements as well as the support system for building agricultural biogas plants in Poland have been presented. There are currently 24 agricultural biogas plants operating in Poland. The fermentation substrates are slurry, food waste and maize silage. It is most often mesophilic fermentation. Produced biogas is combusted in cogeneration and thus obtained electrical and thermal energy is used for the biogas plant's own needs and sold. The support system for biogas plants' operation in Poland is based on a system of certificates. In this system it is cost-effective to use waste for fermentation whilst it is not cost-effective for a biogas plant to run on maize silage. It has been calculated that in Poland the theoretical annual biogas potential for cattle slurry is 3646 million m³, for pig slurry it is 2581 million m³, for poultry manure it is 717 million m³, from maize after seed harvest it is 1044 million m³, from municipal waste biofraction it is 100 million m³ of biogas.     

Status and potential of biogas energy from animal wastes in Turkey

Biogas is a potentially important energy source that can be used for the production of heat, electricity and fuel. It can be produced at wastewater treatment plants, landfills, food and other industrial operations throughout the world. There is largely untapped potential in agricultural operations where animal waste is often land applied or otherwise disposal of without conversion to energy. According to the last agricultural census (2009) in Turkey; there are a total of 3,076,650 agricultural enterprises and approximately 70% of these enterprises are running livestock farming. 10,811,165 of total animal is cattle, 26,877,793 of total animal is small ruminant and 234,082,206 is poultry. The amount of wet waste of these animals is about 120,887,280 t. These wastes could be a major problem for enterprises and cannot be utilized properly. The best way to utilize waste is to produce biogas. In this study, biogas amount which will be obtained from animal waste was calculated for all provinces by using the number of livestock animals and also considering various criteria such as the rate of dry matter and availability. Animal origin waste map of Turkey was also produced with these calculated values. The biogas energy potential of Turkey was found to be 2,177,553,000 m³ (2.18 Gm³) by using the animal numbers in the last agricultural census (2009). The total biogas potential is originated from 68% cattle, 5% small ruminant and 27% poultry. Biogas energy equivalence of Turkey is approximately 49 PJ (1170.4 ktoe). When the prepared waste map is examined; provinces that have more than 1 GJ of biogas energy potential are found to be; Bolu, Bal?kesir, ?zmir, Sakarya, Konya, Manisa, Erzurum, Afyon, Kars and Ankara respectively.     

河南省农业能源生态沼气项目经济效益评价

从社会经济效益的角度,利用BIA指标体系,对县、村、农户三个类别,沼气知识与技术、经济影响和家庭社会影响三个维度,全方位考察了农业能源生态沼气项目对沼气项目户的影响,为大范围内深入推进生态家园富民行动工作提供实证参考.     

水葫芦发酵产气潜力的实验研究

介绍了以水葫芦为实验原料，在25℃环境下，采用批量发酵的工艺，进行发酵产沼气实验。实验结果表明，水葫芦可以作为沼气发酵原料，其产沼气潜力为634mL／gTS或834mL／gVS。     

北京市餐厨垃圾产生状况及厌氧发酵产气潜力分析

随着餐饮行业的发展,越来越多的餐厨垃圾造成的污染成为我们亟待解决的问题.文章通过对北京市城区的餐馆进行实地调查,针对不同规模的餐馆,分别对其餐厨垃圾产生的数量、成分、性质及其收集处理方式、处理费用和最终用途进行了深入的调查分析;并对中国目前的管理政策进行了探讨.文章还通过批式厌氧消化实验对学校食堂的餐厨垃圾进行了产气潜力分析,结果显示在20g/L的容积污染负荷下,经过35 d的中温(35℃)消化,总产气量达到7 380 mL,总甲烷量达到4 023 mL,甲烷含量平均为54.51%,VS去除率为50%,产气率和产甲烷率分别达到369ml/g和201 ml/g,实验表明餐厨垃圾具有很好的产气性能,为进一步研究提供了理论基础.     

Life Cycle Energy Assessment of biohydrogen production via biogas steam reforming: Case study of biogas plant on a farm in Serbia

The aim of this paper is to demonstrate and to quantify energy flows in a life cycle of biogas to biohydrogen production, starting from feedstock materials via anaerobic digestion, biogas upgrading, biohydrogen production, to the end of biogas system (application of digestate as fertilizer in agriculture). The performance of the biogas plant of Mirotin dairy farm in Serbia has been assessed. According to Life Cycle Energy Assessment approach, results obtained in this study have shown that biohydrogen production via biogas steam reforming has negative energy balance (with ?16,837 GJ). It has also been demonstrated that this process is energy unsustainable in an environmental context. In future analysis it would be necessary to consider the other aspects of sustainability, e.g. the economical and social factors in order to estimate the overall sustainability of the biogas utilization pathways, especially having in mind that the technology of converting biogas to hydrogen is still in the development phase.     

Agricultural waste resources and biogas energy potential in rural areas of Lao PDR

Lao PDR lacks of conventional energy resources, such as oil and natural gas, and 100% of fossil fuels are imported from abroad. Fossil fuel consumption in Lao PDR in 2010 was about 561 million liters and rapidly increased to 716 million liters by 2015. However, Lao PDR has a high potential for renewable energy, especially from hydropower, agricultural wastes, and livestock wastes, in which agricultural and livestock annually produced a large amount of agricultural residues as a favorable renewable energy sources. In 2016, productivity crops were estimated for 24,608,840 ton and these products amount can be generated annual agricultural residues for 12,525,000 ton, which can be estimated to total of energy potential was 197,840 GJ or 55,001 GWh. The majority of livestock in country are buffaloes, cattle, swine, and poultry; large amount of livestock manure produced from each region and can be feedstock as substrate for biogas digester, which these amounts were estimated about 1,583,740 kg TS/day, and equivalent to 439,917 m3/day of biogas production or 658,376 kWh/day of energy generation. Therefore, objective of this paper is unique to promote and research development the agroforestry residues and livestock wastes as renewable energy resources, and its energy potential for biofuel production, including, biodiesel, bioethanol and biogas in each region of Laos.     

Estimation of potential biomass resource and biogas production from aquatic plants in Argentina

It is expected that the future construction of the Paraná Medio Hydroelectric Project on the middle Paraná River in Argentina will lead to the accumulation of floating hydrophytes, mainly water hyacinth. Several problems are related to aquatic plants, and steps for efficient control of the vegetation should be taken. If mechanical control is used, the biomass must be processed, preferably in a useful way. Water hyacinth growth in the middle Paraná River has been measured and its bioconversion to methane by anaerobic fermentation determined. It is estimated that gross methane production may be between 1.0 and 4.1 × 10 m³/yr. The fermentation residue production, with a potential value as soil condition, may represent between 54.9 and 221.4 × 10³ t nitrogen/year, i.e., between 2 and 8 times the present nitrogen fertilizer demand in Argentina.     

Estimate of the electric energy generating potential for different sources of biogas in Brazil

The increasing interest in the recuperation of the biogas coming from organic residues, associated with its energetic use is a subject that has been widely discussed. Biogas was merely seen as a sub-product obtained from anaerobic decomposition (without oxygen) of organic residue. In the paper is carried out an evaluation of the quantities of organic residues coming out from the sugar and alcohol industry (vinasse), urban solid and liquid wastes (garbage and sewage) and livestock residues (bovine and swine manure) in Brazil. Finally the electricity generation potential of biogas out of the evaluated sources of organic residues in Brazil is estimated. The results of this study indicate that the potential regarding the production of biogas out of the aforementioned organic residues of electricity production using could meet an energy demand of about 1.05 to 1.13 %. Constraints for biogas energy utilization are identified and discussed.     

Trace compounds of biogas from different biogas production plants

Biogas composition and variation in three different biogas production plants were studied to provide information pertaining to its potential use as biofuel. Methane, carbon dioxide, oxygen, nitrogen, volatile organic compounds (VOCs) and sulphur compounds were measured in samples of biogases from a landfill, sewage treatment plant sludge digester and farm biogas plant. Methane content ranged from 48% to 65%, carbon dioxide from 36% to 41% and nitrogen from <1% to 17%. Oxygen content in all three gases was <1%. The highest methane content occurred in the gas from the sewage digester while the lowest methane and highest nitrogen contents were found in the landfill gas during winter. The amount of total volatile organic compounds (TVOCs) varied from 5 to 268 mg m⁻³, and was lowest in the biogas from the farm biogas plant. Hydrogen sulphide and other sulphur compounds occurred in landfill gas and farm biogas and in smaller amounts in the sewage digester gas. Organic silicon compounds were also found in the landfill and sewage digester gases. To conclude, the biogases in the different production plants varied, especially in trace compound content. This should be taken into account when planning uses for biogas.     

The potential for hydrogen-enriched biogas production from crops: Scenarios in the UK

There is increasing international interest in developing low carbon technologies to provide hydrogen renewably. Hydrogen can be produced through dark anaerobic fermentation using carbohydrate-rich substrates, and methane can be produced in a methanogenic second stage. The suitability of a range of crops for hydrogen and methane production in the UK is examined, using selection criteria including yield, harvest window and composition of the crops. The annual potential for hydrogen and methane production is calculated using the selected crops, taking into account the energy required to grow and harvest the biomass and run the process. The fermentable energy crops fodder beet, forage maize, sugar beet and rye grass were identified as the most suitable substrates for this farm-scale process. A conservative estimate of the amount of agricultural land in the UK excluding permanent grassland not already used for food production or energy crops (currently unused “set-aside” land) has been made (294,960 ha). If this was used to grow a rotation of the selected crops, 9.6 TW h net energy could be produced per year. This equates to electrical power for 2.2 million homes in the UK annually and a reduction of CO₂ emissions by over 2.3 million tones per annum in the UK.     

Assessment of detonation hazards in high-pressure hydrogen storage from chemical sensitivity analysis

In this study, a series of detonation sensitivity analyses have been carried out to assess detonation hazards in hydrogen–air mixture. The present investigation in particular concerns with the effect of elevated initial pressure on the detonation sensitivity, which stems from the renewing interest in preventing possible explosion scenario in hydrogen economy when high-pressure hydrogen storage facilities are contaminated with air. From the steady ZND analyses based on a recently updated comprehensive kinetic mechanism of hydrogen combustion by Li et al. [Int J Chem Kinet 2004;36:566–75] and using improved semi-empirical models, various dynamic parameters, i.e., characteristic cell size and direct initiation energy, for hydrogen–air detonations are estimated and assessed against available experimental data. Results for the hydrogen–air detonation sensitivity indicated that from a purely chemical kinetics consideration, the probability of having a detonation of hydrogen–air mixture at elevated initial pressure is not higher than in other hydrocarbon fuels at elevated initial pressure.     

Assessment of wind energy potential in croatia

In this work, the eolian potential of Croatia (one of the Yugoslav republics) is investigated on the basis of 32 anemograph stations. Mean hourly values were used for calculation of Weibull's distribution parameter c and k, and mean annual and seasonal wind power densities. The vertical extrapolation of wind speeds was based on Justus expression. Mean annual wind energies were calculated for two types of aerogenerators. Analysis of these data showed that in the interior of Croatia, at 10 m above ground, low naturally available wind power densities exist: less than 50 W/m². On the Adriatic basin, in some area along the coast, a wind power of over 300 W/m² may be gained.

The annual natural wind energies at 50 m above ground lie in the continental part between 250 and 1300 kWh/m² and on the eastern part of Adriatic basin between 500 and 8100 kWh/m².     

Study of the energy potential of the biogas produced by an urban waste landfill in Southern Spain

Sanitary landfills have been and continue to be one of the most common ways to dispose of urban waste although such landfills inevitably generate waste management problems. Landfills are an important source of anthropogenic CH₄ emissions. In this sense the European Union has passed regulations regarding the effective management of biogas within the framework of an EU policy for renewable energies. The sealed landfill analyzed in this study is an example of energy recovery, but in this case the biogas generated by the landfill is being re-used to produce electrical energy. This article presents the results of the economic viability study, which was carried out previous to the construction of the installation. The results based on the use of empirical and theoretical models show the biogas to have a 45% proportion of methane and an overall flowrate ranging from 250 to 550 N m³/h. It is presently being used to produce electricity amounting to approximately 4,500, 000 kW h/year. The economic viability of the installation was estimated by means of the Internal Recovery Rate (IRR) for an exploitation period of 7 years.     

养殖废水沼气产气量与沼气发电量均衡问题探讨

针对沼气产气量不均衡造成发电量不稳定的问题,通过对浙江温州市某养殖废水沼气发电工程情况的经济技术分析,提出了给发酵池设置特朗布墙的保温措施与太阳能增温措施以维持池温恒定的办法,从一定程度上解决沼气产气量不均衡的问题.     

生物燃气及生物燃气掺氢燃烧特性的实验研究

为了获得生物燃气及生物燃气掺氢的燃烧特性,文章通过高速纹影系统在定容燃烧弹中研究了CH_4/CO_2在不同CO_2比例、不同当量比、不同初始压力以及不同掺氢比下的层流燃烧特性。研究结果表明:生物燃气的层流燃烧速度随着CO_2掺混比例的增大而降低,随着初始压力的升高而降低;生物燃气掺氢后的层流燃烧速度随着掺氢比的增大而增大;对于生物燃气及生物燃气掺氢而言,火焰的稳定性随着初始压力及掺氢比的增大而降低,随着当量比增大而增大,生物燃气中CO_2的比例对火焰稳定性的影响不大。     

葡萄籽提油前后发酵产沼气潜力研究

在恒温25℃条件下,采取批量发酵工艺,研究了葡萄籽提油前后产沼气潜力。结果表明:葡萄籽TS,VS发酵产沼气的潜力分别为473.65 mL/g和484.55 mL/g,能源转换效率为37.25%;葡萄籽油枯TS,VS发酵产沼气的潜力分别为450.03 mL/g和460.44 mL/g,能源转换效率为36.43%。     

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。     

提高沼气池产气量的探讨

随着人们生活水平的不断提高,人均能耗不断增加,煤、石油、天然气等化石能源日益减少带来的能源安全问题正受到人们的重视.可再生能源的开发利用可以延缓能源危机,是节约化石能源的可行之举.我国人口众多,农村人口占多数,生活耗能较多.在农村地区推广沼气工程建设,是解决分布在广阔的农村人口生活用能,就地取材,因地制宜,方便可行,利国利民的做法,得到了政府的大力倡导和支持.