生活垃圾填埋气的利用

随着我国城镇化建设进程的加快和人民生活水平的提高,填埋气的充分利用成了需要面对的问题。讨论了几种生活垃圾填埋场填埋气的利用方法和途径,分析了相关的技术环节或主要问题。     

垃圾填埋气作为可再生能源的利用

垃圾填埋气的回收和利用是一项经济可行且对环境有益的技术,叙述了目前中国垃圾填埋气利用的情况和新标准要求,结合已成功应用的实例介绍了6种不同的垃圾填埋气作为可再生能源的方式,指出了中国进行填埋气回收利用有广阔的前景。     

垃圾填埋气（LFG）发动机的实验研究

用垃圾填埋气（LFG）作燃料的发动机进行发电具有较大的社会效益和经济效益,本文讨论了LFG发动机燃烧系统各种参数对填埋气发动机性能的影响。实验表明,采用新设计的预燃室燃烧系统后,发动机综合性能有较大的改善。     

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     

大功率垃圾填埋气内燃机发电机组氮氧化物排放研究

兆瓦级燃气内燃机发电机组是垃圾填埋气发电中所采用的主要机型,为了了解其烟气NOx排放状况,分别对两个不同型号和制造商的填埋气发电机组的排放性能进行了测试。结果显示:填埋气发动机的NOx排放浓度较高,但随着发电功率负荷的增加呈现降低的变化趋势,其中,NO2所占比重较大,且NO2/NO比值随发电负荷的增加而增加。由于在所测试的负荷工况中,烟气NOx浓度均高于500 mg/m3的排放限值,因此,对填埋气发电机组进行脱硝治理成为需要关注的一项工作。     

填埋气中二氧化碳净化技术及研究进展

填埋气中由于含有大量的甲烷,具有很高的能源利用价值,并逐渐应用于发电、生产可再生燃料和热电联产等过程中。但填埋气中主要的杂质成分CO2会降低填埋气的热值,影响填埋气的资源化利用,因此CO2的去除对于提高填埋气的品质是很关键的一步。文章主要综述了目前应用较广的填埋气中CO2的净化技术、物理化学吸收法、变压吸附等工艺的原理、特点和研究进展等,并对各工艺进行了对比分析。     

垃圾填埋气发电项目的经济评价及其政策建议

综合分析了垃圾填埋气发电项目经济性，并通过对比分析此类项目国民经济评价和项目财务评价的结果，提出了政府鼓励支持这类项目的方式和建议。     

回收垃圾填埋气发电的热气机燃烧系统研究

针对热气机连续燃烧的特点,采用稀薄燃烧和燃气再循环技术,开发了一套新型旋流扩散燃烧系统和燃烧控制逻辑,建立了利用热气机回收填埋气发电的试验系统,在垃圾填埋场进行了现场系统性能试验.结果表明,改装了燃烧垃圾填埋气燃烧器的热气机系统启动容易,对甲烷浓度适应范围广,燃烧完善,燃烧室内温度分布均匀合理,污染物排放低,并且实现了热气机发电系统无人值守运行.     

中国城市生活垃圾填埋气甲烷产量评估

研究了国内城市生活垃圾清运量、填埋量、构成特点及变化趋势,采用联合国政府间气候变化委员会(IPCC)推荐的用于估算填埋气甲烷产量的IPCC缺省法,对2005～2009年中国城市生活垃圾填埋气甲烷产量进行了初步评估;目前我国年垃圾填埋气甲烷产量已超过50亿m3,可转化为电能200亿kWh左右,人口密度越大、经济越发达地区其填埋气产量越高,在地域上呈现由东到西递减趋势。开发填埋气回收利用工程,不仅能有效地控制温室气体甲烷的排放,而且通过净化后还可获得资源量可观的清洁能源,实现能源与环保的双赢。     

垃圾填埋气供热可行性分析

垃圾填埋气的利用对改善环境、开发能源意义重大,将垃圾填埋气与煤从原产量、发热量、环境三方面进行对比,得出利用填埋气供热具有很高的节能和环境效益的结论。     

PG6531燃气轮机的升级改造

介绍了大庆燃机电厂对GE公司生产的PG6531燃气轮机进行本体升级改造时的新技术应用情况、改造的效果等。     

热回收式CO2制冷系统性能研究

对热回收式CO2制冷系统性能COP进行了计算和分析,结果表明:蒸发温度、气体冷却器出口CO2温度、热水加热器入口水温是影响其COP的主要因素;回热器出口过热度对COP的影响较小,对压缩机的排气温度影响较大;随着排气压力的升高,COP是否出现峰值,取决于气体冷却器入口制冷剂的特征温度;在相同工况下,蒸发温度、气体冷却器出口CO2温度、回热器出口过热度对最佳排气压力的影响较小,热水加热器入口水温是影响最佳排气压力的主要因素。     

初始水化学组分对CO_2矿物储存影响分析

矿物储存被认为是CO2地质储存过程中最安全、最理想的一种储存形式,但此种形式受到诸多因素的影响,储层中的初始水化学组分是其中之一。文章以鄂尔多斯盆地石千峰组地层为例,利用数值模拟方法,通过显著性和相关性分析,定量评价初始水化学组分对CO2矿物储存量的影响。研究结果表明:初始水中Ca2+的主要敏感矿物为赤铁矿、高岭石、钙蒙脱石、菱镁矿和铁白云石,且初始水中Ca2+浓度变化对储层水中Fe2+,Mg2+,HCO3-浓度影响较大,初始水中K+的主要敏感矿物为伊利石,初始水中Na+的主要敏感矿物为钙蒙脱石,铁白云石为石千峰组地层中主要的固碳矿物;时间尺度为1 000 a时,H+,K+,Al3+浓度的改变,对HCO3-,CO2矿物储存量无明显影响,而Na+,Ca2+,Mg2+浓度的升高,会促进系统中矿物之间的转化,降低HCO3-的浓度,增加CO2的矿物储存量,且Ca2+对矿物转化和CO2的矿物储存量的影响最为强烈,Na+其次,Mg2+影响最小。     

沈阳市大辛垃圾场废气发电的可行性分析

文章依据美国EPA的LANDGEM填埋垃圾场垃圾气体排放量的预测软件，对沈阳市新建生活填埋垃圾场废气甲烷的排放量、排放峰值时间、排放气体的特点做了预测。得出在沈阳市，垃圾场甲烷废气转换为能量是可行的。     

The influence of anode gas diffusion layer on the performance of low-temperature DMFC

The influence of the anode gas diffusion layers (GDLs) on the performances of low-temperature DMFCs, and the properties of mass transport and CO₂ removal on these anode GDLs were investigated. The membrane electrode assembly (MEA) based on the hydrophilic anode GDL, which consisted of the untreated carbon paper and hydrophilic anode micro-porous layer (comprised carbon black and 10 wt.% Nafion), showed the highest power density of 13.4 mW cm⁻² at 30 °C and ambient pressure. The performances of the MEAs tended to decline with the increase of the PTFE content in the anode GDLs due to the difficulty of methanol transport. The contact angle measurements revealed that the wettabilities of the anode GDLs decreased as the increase of PTFE content. The wettabilities of the GDLs were improved by addition of hydrophilic Nafion ionomer to the GDLs. From the visualizations of CO₂ gas bubbles dynamics on the anodes using a transparent cell, it was observed that uniform CO₂ gas bubbles with smaller size formed on hydrophilic anode GDLs. And bubbles with larger size were not uniform over the hydrophobic anode GDLs. It was believed that adding PTFE to the anode GDL was not helpful for improving the CO₂ gas transport in the anode GDL of the low-temperature DMFC.     

CaO在生物质定向气化条件下的高温CO_2吸收特性

生物质定向气化可以制备富氢燃气和一定化学当量比的合成气(用于合成醇、醚等),同时有效地减少温室气体排放,是一种可持续的清洁能源转化技术。文章基于生物质定向气化这一背景,结合实际工业生产,采用TG/DTA系统对生物质定向气化条件下CaO吸收CO2的特性进行了研究。实验结果表明:升温速率由10℃/min增加到50℃/min,CaO变温吸收CO2的反应都在800℃左右达到吸收与煅烧平衡,且CaO转化率随升温速率增大而减小;CaO转化率和质量变化速率随CO2浓度增加而增大,根据反应平衡时CO2浓度与温度的关系拟合出CO2平衡分压公式为RCO2,eq=1.16×108exp-21!399/T";CaO恒温吸收CO2的最终转化率随吸收温度的升高先增加后减小,生物质定向气化中CaO吸收CO2的最佳温度为700~750℃;循环吸收实验中CaO转化率随循环次数增加而减小。     

Technical assessment of fuel cell operation on landfill gas at the Groton,CT, landfill

This paper summarizes the results of a seminal assessment conducted on a fuel cell technology that generates electrical power from landfill waste gas. This assessment at Groton, Connecticut was the second such project conducted by the Environmental Protection Agency (EPA), the first being conducted at the Penrose Power Station near Los Angeles, California. The main objective was to demonstrate the suitability of the landfill gas energy conversion equipment at Groton with different conditions and gas compositions than at Penrose. The operation of the landfill gas cleanup system removed contaminants from the gas stream with essentially the same efficacy as at Penrose, even though the quantity and kinds of contaminants were somewhat different. The fuel cell power plant’s maximum output power improved from 137 kW at Penrose to 165 kW at Groton, due to a 31% increase in the heating value of the Groton landfill gas.     

The influence of pre-adsorbed Pt on hydrogen adsorption on B2 FeTi(111)

The hydrogen adsorption properties on a Pt covered Fe-terminated B2-FeTi (111) surface are studied using the Density Functional Theory (DFT). The calculations are employed to trace relevant orbital interactions and to discuss the geometric and electronic consequences of incorporating one Pt atom or a Pt monolayer on top of the FeTi surface. The most stable adsorption site is a distorted FCC hollow for one Pt atom and from this location we build the Pt monolayer (ML). The H-adsorption energy is very close among BRIDGE, HCP and FCC hollow sites (∼−0.45 eV) being lower for the TOP site (−0.34 eV) in the case of a Pt(111) fcc surface. In the case of a Pt ML/FeTi, the H more stabilized on a BRIDGE site (∼−1.13 eV) interacting with both a Pt and Fe atom. We also computed the density of states (DOS) and the overlap population density of states (OPDOS) in order to study the evolution of the chemical bonding after adsorption.     

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%.     

Enhanced activity of NiZrBEA catalyst for upgrading of biomass pyrolysis vapors to H2-rich gas

The main objective of these studies was development of competitive catalyst for the upgrading of biomass pyrolysis vapors to H₂-rich gas. The performed experiments were devoted to determination of the effect of incorporation of zirconium into the structure of BEA zeolite on the performance of NiBEA in the mentioned process. Moreover, the most important parameters responsible for the increased activity of NiZrBEA catalyst in comparison to nickel supported on parent zeolite have been identified. The activity of synthesized catalysts was tested in two step fixed bed quartz reactor. Firstly, cellulose or pine were heated to the 500 °C in order to decompose lignocellulosic feedstock. Then, formed pyrolysis vapors were directed through catalyst bed (700 °C) where their upgrading took place. The obtained results revealed that an introduction of zirconium in the structure of BEA zeolite allowed for the increase in the efficiency of Ni catalyst in the formation of H₂-rich gas. It was related to the increase in pore volume of the synthesized materials, formation of smaller nickel oxide crystallites and creation of the catalysts with moderate acidity.