垃圾衍生燃料作为生活垃圾焚烧炉辅助燃料的费用-效益分析

在分析垃圾焚烧技术及垃圾衍生燃料(RDF)技术的基础上,进一步分析了中国城市生活垃圾特点,表明了中国更适合利用陈旧垃圾制造高品质的RDF.通过RDF用于生活垃圾焚烧炉辅助染料的费用-效益分析,显示了RDF辅助城市生活垃圾焚烧是完全可行的,具有显著的经济、环境和社会效益.     

生活垃圾与煤混合燃烧特性及动力学分析

利用热重分析仪对生活垃圾与煤混合试样的燃烧特性及热反应动力学进行了实验研究,考察了不同配比混合试样的着火温度、燃尽温度、最大燃烧速率及最大燃烧速率温度等燃烧特征参数,并用Coats-Redfern积分法对其进行了燃烧动力学分析,确定了燃烧动力学方程,求出了反应活化能Ea及指前因子A。实验结果表明:生活垃圾与煤混合燃烧时均保持各自的燃烧特性;混合燃料中随着生活垃圾掺量的增加,热重曲线向低温区转移,燃尽点逐渐降低,综合燃烧特性指数明显增大,生活垃圾能改善煤的燃烧性能;生活垃圾及其与煤混合燃烧出现两个燃烧阶段,分别遵循二级和一级反应机理,煤燃烧只出现一个燃烧阶段,遵循一级反应机理;混合燃料燃烧反应活化能Ea与指前因子A存在动力学补偿效应。     

城市生活垃圾、污泥和煤粉混合燃料热值的研究

为了寻求生活垃圾和污泥的高效资源化、能源化方法.选取生活垃圾、污泥和煤粉的混合,枯枝落叶,助燃剂MnO2,脱硫剂 CaO 为控制因子,安排正交试验,成型加工为混合燃料.测定其热值,并通过正交分析,筛选出燃料最大热值组合,即混合时垃圾、污泥、煤粉的比例为 1:1:2,枯枝落叶所占比例为 0%,助燃剂 MnO2 含量为 0.18%,脱硫剂 CaO 含量为 1.5/(100 g),该燃料的热值为 17.8898 kJ/g.为该混合燃料的推广与应用提供理论依据.     

城市生活垃圾机械生物处理效果

采用机械生物处理工艺研究了淋洗水解、脱水与好氧生物干燥对城市生活垃圾的处理效果.结果表明:在淋洗水解及压榨脱水机械生物处理阶段,控制淋洗液与生活垃圾重量比2∶1,停留时间1.2 ～1.4 d条件下,生活垃圾可以减量49.7％.而过程中产生的淋滤液COD为32 939 mg/L、pH为5.1、COD∶N∶P=261∶5∶3.6,可以进行厌氧消化处理或作为碳源进行资源化利用.在好氧生物干燥阶段,通风量采用0.08 m3/min,2～3d堆体温度可升至73℃,7d左右即可产出LCV高达15 000 kJ/kg左右的高品位垃圾衍生燃料(RDF),其产率为38.2％,氯元素含量低于0.5％,重金属含量较低,满足燃料要求.     

采用循环流化床技术焚烧城市生活垃圾

根据目前我国城市生活垃圾热值偏低的实际情况 ,提出以煤为辅助燃料 ,采用循环流化床焚烧技术处理生活垃圾 ,可大幅度降低运行成本 ,符合国情。阐述了循环流化床焚烧技术在降低NOx、SO2 和二噁等方面的优越性。尾气处理建议采用喷活性碳 +布袋除尘组合工艺 ,飞灰处理建议采用高温熔融处理     

采用循环流化床技术焚烧城市生活垃圾

根据目前我国城市生活垃圾热值偏低的实际情况，提出以煤为辅助燃料，采用循环流化床焚烧技术处理生活垃圾，可大幅度降低运行成本，符合国情。阐述了循环流化床焚烧技术在降低NOx、SO2和二噁英等方面的优越性。尾气处理建议采用喷活性碳 布袋除尘组合工艺，飞灰处理建议采用高温熔融处理。     

垃圾分类背景下厨余垃圾剔除比例对生活垃圾焚烧厂NOx排放的影响

收集了生活垃圾焚烧厂关停SNCR时燃料的N排放数据以及与之对应的工况和燃料特性数据,并分析各影响因素对燃料N转化过程中不同环节的影响机理.结果表明,在工业化生产中,燃料N转化率与炉温、垃圾含水率之间不存在显著联系,而随N元素含量和固定碳含量的增加而降低,随过剩空气系数、H/N、O/N的增加而升高.据此提出了符合实际生产条件的燃料N转化路径图.该路径图表明,燃料特性对燃料N转化率和NOx生成浓度起到了决定性作用,并进一步量化了H/N和固定碳含量这2个参数与燃料N转化率之间的关系.提出通过将厨余垃圾从生活垃圾分出的方法来减少NOx生成,并以国内典型城市为例,研究了分出不同比例厨余垃圾的情况下,燃料N转化率和NOx生成浓度的变化趋势.本研究表明通过分出厨余垃圾的方法,能够降低垃圾焚烧厂的脱硝成本及氨逃逸风险,可为进一步控制生活垃圾焚烧过程中的NOx排放提供参考.     

城市生活垃圾和污水处理厂剩余污泥混合发酵的原料配比优化研究

以城市生活垃圾和污水处理厂的剩余污泥为混合原料,研究了混合原料的不同配比对厌氧发酵过程及产气的影响。结果表明:城市生活垃圾与剩余污泥以挥发性固体(VS)质量比为2∶1混合后,厌氧发酵效果最好,累计产气量最高,达到8 721mL,发酵后的总固体(TS)、VS、COD去除率分别达43.65%、35.98%、47.88%;各实验组在发酵过程中的pH、氨氮浓度和碱度均在合理范围内,未对厌氧发酵反应造成影响;以适当配比的城市生活垃圾和剩余污泥为混合原料,进行中温联合厌氧发酵是可行的,联合厌氧发酵可以弥补单一原料的缺陷,在一定程度上改善厌氧发酵效果。     

固体回收燃料焚烧技术的研究现状及发展方向

固体回收燃料(SRF)是由城市生活垃圾(MSW)经机械生物处理(MBT)而得,具有高热值、低氯和含汞的特点,是继垃圾衍生燃料(RDF)之后的一种新型燃料。目前SRF焚烧技术在国内外已有一定的基础研究,但仍需要向大规模、高参数(高蒸汽温度和压力)、稳定运行方向发展。从垃圾焚烧现状入手,简述了国外SRF焚烧和共处置技术的研究现状,同时回顾了国内对MSW和RDF焚烧技术的相关研究,分析了SRF焚烧和共处置时污染物排放的规律,以及SRF对共处置锅炉运行工况的影响。最后指出了实现SRF焚烧技术的大规模、高参数工业应用必须研究的3个方面,包括:SRF的分类方法和燃烧模型,烟气净化系统的改进,SRF焚烧对锅炉腐蚀、结渣和积灰生长的影响。     

垃圾堆肥的资源化利用

城市垃圾的堆肥处理，就是将城市生活垃圾中一部分不可降解的无机物，控制一定条件，让其在微生物的作用下，降解转化为稳定的腐殖物。将生活垃圾处理成有机肥料，从源头消除了垃圾，减轻城市生活垃圾给环境造成的压力，避免二次污染，而且在解决垃圾处理问题的同时，又为农作物和园林等提供必要的肥料，从而实现生活垃圾的无害化、减量化和资源化。在实现垃圾堆肥资源化利用的同时，需要注意堆肥产品的使用对象，避免使用不当带来的影响。     

The Sulfur Balance of Incinerators

Municipal refuse usually contains only 0.10-0.15% sulfur. During combustion a minor fraction of the sulfur is released as SO₂, while the major fraction is fixed in the ash, which contains alkaline oxides. Contrasted with coal and heavy fuel oil, municipal refuse is a minor to negligible source of SO₂ air pollution.     

香港城市固体废物系统管理

本文以大量翔实的数据介绍了香港对城市固体废物的系统管理,即分类、收集、监测分析、处理和预测评价。香港环保署自８０ 年代开始对城市固体废物进行监测并系统管理。在全港设置了３ 个大型策略性填埋场、５ 个垃圾转运站、１ 个垃圾焚烧厂（１９９７ 年５ 月关闭） 和１个化学废物处理中心。目前,香港政府正筹建一个新的、技术先进的焚烧厂。从１９８６ ～１９９７年,这些废物处理设施处理全港废物量为８９６０ ～２４３００ｔ／ｄ,其中城市固体废物比例每年不等,最低为３０ ．７ ％ ,最高为６５ ．５ ％ 。１９９７ 年,这些废物中可循环再利用物接近５０ ％ ,出口部分达１２０ 多万吨,回收资金２０ 多亿港元。根据历年来城市固体废物量与本地生产总值（ＧＤＰ）和人口数量的密切相关性,预测出２０１１ 年城市固体废物人均产率为２ ．５６ｋｇ／ 人·ｄ, 城市固体废物量为１２８１０ ｔ／ｄ。城市固体废物系统管理紧迫而重要,香港的经验是值得我们借鉴的。     

Fatal flaws in measuring landfill gas generation rates by empirical well testing

Well testing procedures, such as the Tier 3 methodology specified in the U.S. Code of Federal Regulations (CFR) Subtitle D, are commonly used for directly estimating landfill gas (LFG) emissions at municipal solid waste (MSW) landfills. Similar procedures are also used to estimate LFG generation rates for the design of LFG-to-energy projects. These methodologies assume that the LFG generation rate equals the extraction rate of a test gas well within its radius of influence (ROI). The ROI is defined as the distance from the extraction well at which the induced pressure drop is immeasurable by some standard of precision. Based on fluid dynamic principles, Tier 3 and similar methodologies are demonstrated to be incapable of providing reliable estimates of the LFG generation rate. These tests may either over- or underestimate the LFG generation rate depending on the precision with which the ROI is determined, but they will only coincidentally produce an estimate that accurately represents the actual LFG generation rate. Fluid dynamic principles dictate that the actual LFG generation rate can only be estimated if the pneumatic properties of the refuse and cover materials as well as the excess pressure in the refuse caused by LFG generation are known or can be estimated.     

城市生活垃圾中转站举升装置设计与应用

对地平式城市垃圾中转站的 3种举升装置进行了详细分析 ,指出了其存在的问题 ,提出了一种新型的链条式城市垃圾中转站举升装置 ,它结构紧凑 ,运行平稳可靠 ,成本低 ,噪音小 ,节能省电 ,是垃圾中转站新型优选产品 ,现已成功应用于环卫工程中     

Dioxins not detected in effluents from coal/refuse combustion

No 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin was detected in effluents from a power plant burning coal supplemented with processed municipal wastes. These negative findings, in contrast with the many reports of the presence of dioxins from waste incineration, are proposed to be due to the high temperature of 1200°C for the combustion of small pieces of refuse with adequate oxygen for times sufficient to insure complete oxidation.     

Atmospheric Emissions from Open Burning

Emission data have been derived from the simulated open burning of municipal refuse, landscape refuse, and automobile components. The data confirm that disposal of refuse by open, uncontrolled burning invariably leads to higher emissions than incineration and creates an unnecessary air pollution problem.     

城市生活垃圾降解率分析研究

针对城市生活垃圾降解率研究不足的现状,结合室内物理模拟实验,对垃圾温度和垃圾降解率的变化规律进行分析研究。研究结果表明,填埋初期垃圾填埋体温度升高较快,服从三次曲线变化规律;温度对垃圾降解率有重要的影响,单一温度下垃圾降解率随时间变化近似符合微生物生长曲线;不同温度下,温度高,垃圾降解率快,试验证明41.00、45.00℃垃圾降解率最快,垃圾降解率相差不大,可以认为温度高于41.00℃时垃圾降解率可以按照41.00℃时垃圾降解率计算。     

The leachability and chemical speciation of selected trace elements in fly ash from coal combustion and refuse incineration

A laboratory leaching test has been used to predict the potential mobility of As, Se, Pb and Cd in landfilled fly ash produced by coal combustion and refuse incineration. These waste residues also formed the basis of a speciation study in which the valency states of As and Se and the chemical forms of Pb and Cd have been determined. Selenium displayed the greatest leachability in each ash type, despite being present at relatively low concentrations in both materials. Substantial amounts of other trace elements were also leached, particularly Pb and Cd from refuse ash and As from coal ash. Chemical associations of Pb and Cd were examined by a sequential extraction procedure. In coal fly ash, both elements were mostly present in the residual fraction, while in refuse ash these elements were mainly associated with the exchangeable fraction. Water-soluble extracts of coal fly ash contained As exclusively as As(V); high background interference prevented the detection of water-soluble As in refuse ash. Selenium was present largely as Se(IV) in aqueous extracts of both ash types. The value of speciation techniques and leaching tests as predictors of environmental behaviour is discussed in conjunction with results of routine trace element determinations and plant uptake studies.     

沭阳县生活垃圾现状调查及处理方案的优化选择

通过对沭阳县生活垃圾的现状调查与监测,并对国内外垃圾处理技术进行比较和优化,重点介绍垃圾处理新技术ITAD垃圾处理的方法,实现垃圾完全资源化利用,具有良好的经济效益和环境效益。     

Microbial utilization and transformation of humic acid-like substances extracted from a mixture of municipal refuse and sewage sludge disposed of in a landfill

The purpose of the research was to establish whether humic acid-like substances (HA) related to municipal refuse disposed of in a landfill can resist microbial degradation and if they contribute, in that way, to long-term stabilization of landfill refuse. Using a mixture of 0.1 M Na(4)P(2)O(7) + 0.1 M NaOH, we extracted HA from municipal refuse mixed with sewage sludge and disposed of for up to 12 months, in a 40-m(3) model landfill. In laboratory experiments under aerobic conditions, up to 50% of HA was utilized as a supplementary source of nutrients by an assemblage of soil microorganisms in only 21 days. The microbial utilization was enhanced to over 80%, and up to 98%, respectively, if HA served as the sole source of carbon or nitrogen. Remaining HA which could be re-isolated from microbial cultures were lower in carbon (<12%) and nitrogen (<2.3%). Spectroscopic analysis (UV, Vis, FTIR) indicated losses, especially in aliphatic structural units, and a relative enhancement in aromatic structures. It was postulated that for their high degree of degradability, HA indigenous to that anthropogenic environment would not play an important role in the long-term stabilization of landfill refuse.