南通某垃圾填埋场产气量及发电效益估算

文章以南通市某垃圾填埋场为研究对象,利用USEPA开发的Land GEM模型进行填埋场产气量估算,并基于模型估算产气量进行发电成本效益分析。根据填埋场垃圾组分及填埋量等条件确定模型参数(甲烷产气率为0.106 a-1,产甲烷潜力为68 m3/t),将模型参数输入Land GEM模型估算出40 a的填埋气理论产气量。填埋场产气量在封场后一年(即2028年)达到最大,为4 957.45 m3/h,填埋气可收集量(收集率为30%)为1 487.23 m3/h。根据填埋气可收集量选择2台1 MW燃气内燃机进行发电,并进行成本效益分析,结果发现,一次性投资成本约为1 815万元,第一年收入能达到820.885万元,项目运行两年2个月就能完成成本的回收。     

我国垃圾填埋场填埋气体排放和回收利用现状分析

城市生活垃圾填埋气体的回收和资源化利用是一项经济可行且对环境有益的技术。本文介绍了我国目前垃圾填埋气体产生、排放及利用情况,分析了几种填埋气体利用技术的特点及其在我国的适用性,并提出了未来我国城市生活垃圾处理的主要方向,即建立配备填埋气体回收装置的卫生填埋场。     

3种垃圾填埋气预测模型的比较研究

文章分析了3种典型的生活垃圾填埋气预测模型:德国模型、IPCC推荐模型、动力学模型(Marticorena模型)的机理;以重庆市长生桥垃圾填埋场为例,探讨了3种模型的参数确定,据此预测了相应填埋堆体的长期产气情况,比较讨论了各模型预测结果的差异,并对其适用性进行了分析.结果表明,3种模型反映的填埋气体变化的趋势是一致的,3个模型所产生填埋场气的峰值大小顺序为:IPCC推荐模型(4.2×107m3/a)＞Marticorena动力学模型(4.1×107m3/a)＞德国模型(3.6×107m3/a).根据现场实测数据的验证,在封场之前采用德国模型进行测算比较合适;封场之后采用IPCC或Marticorena动力学模型则更加符合实际情况.     

中国垃圾填埋场填埋气体排放和回收利用现状分析

城市生活垃圾填埋气体的回收和资源化利用是一项经济可行且对环境有益的技术。本文介绍我国目前垃圾填埋气体产生，排放及利用情况，分析了几种填埋气体利用技术的特点及其在我国的适用性并提出了未来我国城市生活垃圾处理的主要方向，即建立配备填埋气体回收装置的卫生填埋场。     

垃圾处理方式对温室气体减排作用影响分析

介绍了填埋、焚烧和堆肥3种垃圾处理方式对温室气体减排的影响;分析了这3种不同处理方式下,各种温室气体的产气模型,采用IPCC推荐模型;根据填埋气发电、焚烧发电、有机垃圾堆肥这些温室气体减排措施,分析项目的流程边界,得到温室气体减排量计算公式;提出垃圾综合处理才能实现较好的温室气体减排效果。     

福州红庙岭生活垃圾填埋气体回收利用的CDM可行性研究

对国内几个已批准的填埋气体收集利用CDM项目,在比较分析的基础上,结合福州市红庙岭生活垃圾填埋场具体情况,对该场填埋气体回收利用的CDM可行性进行研究及效益评析。结果表明:只要尽快合理地开发该项目,不仅能大大减少填埋气体的排放量,同时也减排了因替代其它能源产生电能而带来的温室气体。因此,具有同类垃圾填埋场的城市也应通过国家相关部门积极申报填埋气体发电CDM项目。     

基于发电机组布局的垃圾填埋气减排优化模型

文章结合某市3个垃圾填埋场CDM项目扩建改造工程,利用填埋气收集利用方法学ACM0001ver.1与AMS-I.D.ver.6、0-1整数规划方法,以填埋气发电系统GHG年减排量最大为目标,选取建设成本、经济利润、填埋气收集、供电等为约束条件,构建了基于发电机组布局的垃圾填埋气GHG减排优化模型。模型优化方案显示:案例工程优化后发电机组布局发生了较大变化,工程总投资降低7.87%,垃圾填埋气发电系统正常运行且产气量稳定条件下,达产年(2020年)最大GHG年减排当量为6 314 397 t(CO2e),较案例推荐方案增加了11.55%,经济效益提高了19.57%,说明合理调整垃圾填埋场CDM项目扩建改造工程发电机组的布局,不但可以减少工程总投资、提高经济效益,还可以有效缓解由于填埋气大量排放造成的温室气体效应。     

垃圾填埋气体的产生及其在国外的回收利用

垃圾填埋气体的产生及其在国外的回收利用北京市环境卫生科研所逢辰生一、填埋生物气产生的最佳条件城市生活垃圾中一般含有６５％～７５％的有机成分，这些有机物质一旦作填埋处理后就会分解。分解过程见图１。图１城市生活垃圾中各种物质的分解过程当垃圾在填埋场进行处...     

红庙岭生活垃圾填埋气体回收利用的CDM可行性研究

对国内几个已批准的填埋气体收集利用CDM项目，在比较分析的基础上，结合福州市红庙岭生活垃圾填埋场具体情况，对该场填埋气体回收利用的CDM可行性进行研究及效益评析。结果表明：只要尽快合理地开发该项目，不仅能大大减少填埋气体的排放量，同时也减排了因替代其它能源产生电能而带来的温室气体。因此，具有同类垃圾填埋场的城市也应通过国家相关部门积极申报填埋气体发电CDM项目。     

生活垃圾填埋场臭气评价与实例研究

通过对生活垃圾填埋场填埋气体臭气物质组分及其含量的分析,依据现行的国家有关标准,根据臭气浓度和强度的关系式,转化为该气体臭气强度,并给出环境影响评价标准值.以深圳市下坪垃圾填埋场为实例,结合现场监测和模型预测,验证该标准的实用性,该标准值能科学、直观地反应出恶臭污染物对大气环境的影响,是一种比较实用的评价方法.     

垃圾填埋气在发电方面的应用--某13.8MW电厂的运行经验

根据欧盟能源政策有关促进可再生能源和热电联产的计划，距雅典市7km远的Ano Liosia垃圾填埋场兴建了一座热电厂。结合填埋场的具体情况，对热电厂的建设和运行进行了一系列调整。填埋场产生的填埋气用来进行热电联产。由竖井和水平管网组成的集气系统将填埋气引入热电厂，产生的电足够供应15000人的城镇。热电厂2001年投入运行，包括11个热电机组，总装机容量达13．8MW，年发电量约为110GWh，全部并入电网。烟气余热回收的热量用来生产蒸汽和热水。年产热约16．5MW。文章介绍了Ano Liosia热电厂的运行经验。     

渗滤液流失造成的MSW填埋气潜能减量

中国城市生活垃圾(MSW)中易生物降解的有机质能产生大量可造成有机污染的渗滤液,这些渗滤液的流失对填埋垃圾的产气能力会产生不利影响,为了确定损失的这部分渗滤液的产气能力,对模拟填埋100 d的处于酸化阶段的渗滤液实施了70d的厌氧消化试验.试验过程中对渗滤液的产气量、甲烷含量、产沼气潜能、pH变化规律及COD去除率做了监测研究.结果表明,渗滤液沼气累积产量为34.55 ml/ml,甲烷浓度为65.0%,渗滤液产甲烷潜能为22.46 ml/g;pH值在开始两天下降至6.7,并在产气阶段逐渐上升到8.3;渗滤液的COD去除率为83.8%.基于对模拟填埋渗滤液的沼气潜能研究,一个开始填埋100d后的中国MSW填埋场流失的填埋气潜能已达到11.5%.     

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.     

欧盟国家新兴的生物天然气产业

欧盟国家在近几十年发展沼气的过程中,经历了从以处理生活污水无害化产生的污泥为主,到以获取优质可再生能源为主、能源和环保兼顾的战略性转折,原料范围显著扩大,规模迅速向产业化方向发展。欧盟2007年沼气总量达到约100×108m3,其中50%来自垃圾填埋气,30%来自农业废弃物和能源作物,20%来自下水道处理产生的污泥。瑞典在全球率先开发车用生物天然气;德国的沼气厂由2000年的1000家发展到2010年的约5000家,发电产能为2700MW;瑞士则非常重视可持续的原料供应及沼气发酵技术的研究创新和开发;英国现有38座沼气厌氧工程,垃圾填埋气占全部沼气产量的约90%,主要用于燃气轮机发电和供热;法国议会于2010年7月通过新环保法案,强制性收购生物天然气并给予并入天然气管网的优惠性补贴。减排温室气体和提高天然气自给率是欧盟产业沼气大发展的最大推动力,而立法和扶持政策在其产业沼气的成长阶段发挥了决定性作用。随着传统原料资源量的日渐匮乏,沼气专用能源作物应运而生,其潜力远大于其他资源。能源作物青贮后可以长期不霉变、不腐烂,这对于大型沼气企业全年稳定生产具有决定性意义。另外,沼气的单位土地能量产出率是最高的。我国天然气资源短缺,大力发展产业沼气将对提高我国天然气自给率和实现应对全球气候变化中长期规划目标起到不可忽视的作用。     

Controlling mechanism of coal chemical structure on biological gas production characteristics

To find the effect of coal chemical structure on biogas production, Lignite B was collected and extracted with nitrogen methylpyrrolidone (NMP), acetone and 0.60 mol/L NaOH. Simultaneously, methanogenic bacteria were enriched, and gas production experiments involving solvent extraction from residual coal and secondary gas production experiments involving coal were performed. The characteristics of biogas production, microcrystalline structure and coal chemical structure were analyzed. The results showed that the biogas production capacity of residual coal extracted by different solvents differed. The biogas production capacity of residual coal extracted by 0.60 mol/L NaOH was severely inhibited. The biogas production capacity of residual coal extracted by NMP and acetone was enhanced compared with that of raw coal. In contrast, primary residual coal still exhibits potential for methane production, but the methane production efficiency was reduced. Changes in the microcrystalline structure and functional groups of residual coal showed that solvent extraction increases the spacing and stacking height of the aromatic lamellae of coal, reduces the hydroxyl, methyl, methylene and aromatic hydrocarbon levels in coal, loosens the macromolecular network structure of coal, and enhances the connectivity of pores and fissures, thus allowing methane-producing bacteria to enter the coal mass and create favorable conditions for gas production through interactions between the two. X-ray photoelectron spectroscopy measurements showed that the secondary gas production increased the C content on the coal surface, decreased the O content and the O/C ratio, thus promoting the consumption of oxygen-containing functional groups on the coal surface to further produce gas.     

When does decentralized production of biogas and centralized upgrading and injection into the natural gas grid make sense?

The production of biogas through anaerobic digestion is one of the technological solutions to convert biomass into a readily usable fuel. Biogas can replace natural gas, if the biogas is upgraded to green gas. To contribute to the EU-target to reduce Green House Gases emissions, the installed biogas production capacity and the amount of farm-based biomass, as a feedstock, has to be increased. A model was developed to describe a green gas production chain that consists of several digesters connected by a biogas grid to an upgrading and injection facility. The model calculates costs and energy use for 1 m³ of green gas. The number of digesters in the chain can be varied to find results for different configurations. Results are presented for a chain with decentralized production of biogas, i.e. a configuration with several digesters, and a centralized green gas production chain using a single digester. The model showed that no energy advantage per produced m³ green gas can be created using a biogas grid and decentralized digesters instead of one large-scale digester. Production costs using a centralized digester are lower, in the range of 5 €ct to 13 €ct per m³, than in a configuration of decentralized digesters. The model calculations also showed the financial benefit for an operator of a small-scale digester wishing to produce green gas in the cooperation with nearby other producers. E.g. subsidies and legislation based on environmental arguments could encourage the use of decentralized digesters in a biogas grid.     

Technical/economic/environmental analysis of biogas utilisation

Biogas may be utilised for Combined Heat and Power (CHP) production or for transport fuel production (CH₄-enriched biogas). When used to produce transport fuel either electricity is imported to power the plant or some of the biogas is used in a small CHP unit to meet electricity demand on site. The potential revenue from CH₄-enriched biogas when replacing petrol is higher than that for replacing diesel (Irish prices). Transport fuel production when replacing petrol requires the least gate fee. The production of greenhouse-gas is generated with cognisance of greenhouse-gas production with the scheme not in place; landfill of the Organic Fraction of Municipal Solid Waste (OFMSW) (20% of biomass) with and without combustion of landfill gas is investigated. The transport scenario with importation of brown electricity generates more greenhouse-gas than petrol or diesel, when the ‘do-nothing’ case involves combustion of landfill gas. The preferred solution involves transport fuel production with the production of CHP to meet electricity demand on site. A shortfall of this solution is that only 53% of biogas is available for export.     

垃圾填埋气产量的估算与测试

针对某垃圾填埋场,采用IPCC模型和Gardner-Probert模型理论对填埋气总产量和年产气量进行了计算,结果表明,以600m3/h的抽气量进行利用可使用10a以上,具有很好的利用前景。利用开发出的填埋气测试装置,进行了单井抽气能力的测试,通过长达半年的连续抽气运行实验,单井抽气流量可以稳定在40m3/h,为工程设计提供     

Estimation of hydrogen output from a full-scale plant for production of hydrogen from biogas

An experiment was conducted to produce hydrogen from biogas using dairy cow waste as the main material, and the results were used as the basis for simulation of a full-scale plant (referred to here as a BTH-plant) combining a biogas plant and a hydrogen production facility. In this study, BTH-plant operation method to minimize greenhouse gas emissions was identified using linear programming, and the available hydrogen supply capacity was estimated.     

Methane generation in landfills

Methane gas is a by-product of landfilling municipal solid wastes (MSW). Most of the global MSW is dumped in non-regulated landfills and the generated methane is emitted to the atmosphere. Some of the modern regulated landfills attempt to capture and utilize landfill biogas, a renewable energy source, to generate electricity or heat. As of 2001, there were about one thousand landfills collecting landfill biogas worldwide. The landfills that capture biogas in the US collect about 2.6 million tonnes of methane annually, 70% of which is used to generate heat and/or electricity. The landfill gas situation in the US was used to estimate the potential for additional collection and utilization of landfill gas in the US and worldwide. Theoretical and experimental studies indicate that complete anaerobic biodegradation of MSW generates about 200 Nm³ of methane per dry tonne of contained biomass. However, the reported rate of generation of methane in industrial anaerobic digestion reactors ranges from 40 to 80 Nm³ per tonne of organic wastes. Several US landfills report capturing as much as 100 Nm³ of methane per ton of MSW landfilled in a given year. These findings led to a conservative estimate of methane generation of about 50 Nm³ of methane per ton of MSW landfilled. Therefore, for the estimated global landfilling of 1.5 billion tones annually, the corresponding rate of methane generation at landfills is 75 billion Nm³. Less than 10% of this potential is captured and utilized at this time.