城市生活垃圾自热焚烧新技术

介绍了一种城市生活垃圾直接气化熔融焚烧方法--垃圾自热焚烧新方法的工艺及特点.     

谈我国城市生活垃圾采用焚烧技术的应用和发展

经过十多年的探索，我国在城市生活垃圾焚烧技术和设备的研制开发和设备制造方面已具备了一定的技术基础，在我国再选用城市生活垃圾焚烧技术时，应根据我国城市生活垃圾结构特点和国情，立足依靠自己的力量走国产化道路，在已有的焚烧技术基础上开拓创新，形成我国自己的垃圾焚烧处理和综合利用技术系统。这对降低由于采用引进焚烧技术而带来的昂贵造价十分有利，对开发我国垃圾焚烧技术和设备也是完全必要的。     

城市生活垃圾的热工特生分析及焚烧过程

本文系统地分析与论述了城市生活垃圾的热工特生及焚烧过程，通过对垃圾的元素和民分分析，估算垃圾失氏位发热值，来确定垃圾能否采用焚烧技术进行处理。同时对焚烧炉体体必须重视预热干燥段结构的设计，也进行了论述 。     

气化熔融技术处理城市生活垃圾研究进展

气化熔融技术处理后的灰渣中二恶英含量和重金属浸出毒性都符合相关标准。气化熔融技术可分为灰渣全熔融的气化熔融技术和飞灰熔融的气化熔融技术,其中飞灰熔融的气化熔融技术较适合处理低热值城市生活垃圾。垃圾成分不同,最佳气化温度也相应改变,根据不同地区垃圾成分的差异设定适合的气化温度、优化炉膛参数是非常有必要的。炉膛内加入SiO2和CaO可降低灰渣的熔融温度,增加重金属固化率。     

熔渣法城市垃圾高温焚烧技术试验研究

介绍了应用冶金技术开发的一种熔渣法处理城市垃圾的新工艺。用该工艺处理垃圾,具有使垃圾彻底无害化、减容化、资源化等特点,尤其适合特种垃圾的处理。为我国城市垃圾处理开拓了一条新路。     

城市生活垃圾高温裂解发电技术

介绍了一种先进的城市生活垃圾处理技术——高温裂解技术,阐述了该技术的主要特点,分析了该技术在中国的应用前景。     

第二代城市生活垃圾焚炉—气化熔融炉

本文介绍了一种新的城市生活垃圾焚烧处理方式-气化熔融炉的工艺过程,国外发展现状和研究进展.在分析国内外城市生活垃圾特点的基础上,提出了一种适合于我国垃圾现状的气化熔融处理方式.     

熔渣法城市生活垃圾高温焚烧过程控制模型

建立了熔渣法城市生活垃圾高温焚烧过程控制数学模型，通过模型在线计算，调节辅助燃料加入量和助燃氧气量，自动实现对垃圾焚烧炉的稳定燃烧实时控制。     

高温富氧空气燃烧加热时间和氧化烧损研究

针对钢坯加热工艺提出一种高温富氧空气燃烧新技术.建立能量平衡方程、钢坯导热微分方程、氧化层生成线性和抛物线增长的组合方程.研究表明:在预热900℃和含氧体积分数为54%条件下燃烧与传统燃烧相比,加热时间可缩短38%,生产率可提高61%,热效率可提高30.5%,氧化烧损可降低40%.在含氧体积分数为36%以内提高空气预热温度和含氧浓度,可明显地提高热效率,降低钢坯的氧化烧损.     

高温空气燃烧技术在垃圾焚烧炉上的应用探讨

我国城市垃圾有热值低、成分不稳定等特点,因而按常规方法不易点火和稳定燃烧。利用近年开发出来的高温空气燃烧技术可以对低热值燃料实现稳定燃烧。文章提出了将高温空气燃烧技术应用在城市垃圾焚烧炉上的新方法,并对该技术进行了相应的热工分析。     

高温空气燃烧技术用于生活垃圾焚烧处理的分析

高温空气燃烧技术可以较好地弥补生活垃圾燃烧处理中的不足,并可以克服垃圾燃烧中的二次污染问题。提出了两套垃圾燃烧处理系统,并设计了两种高温空气垃圾燃烧系统中关键部件之一的高温空气发生器。     

Air Permeability of Waste in a Municipal Solid Waste Landfill

The permeability of compacted municipal solid waste in a landfill with respect to air (or gas) flow was estimated using a short-term air injection test. Air was added to 134 vertical wells installed at three different depths at flow rates in the range of 0.14?–1.4?m3?min?1 and the corresponding steady state pressures were recorded. The permeability of the waste with respect to airflow (described here as the air permeability) was estimated for different anisotropy ratios (kr/kz = 1, 10, and 100) using a steady state, two-dimensional, axisymmetric analytical fluid flow model in conjunction with the measured flow and pressure data. The air permeability of landfilled municipal solid waste modeled as an isotropic medium was found to range from 1.6×10?13 to 3.2×10?11?m2. The estimated air permeability results were on the low end of values previously applied to model landfill gas flow. Estimated air permeability decreased significantly with increasing waste depth. The lower permeability encountered in the deeper layers was primarily attributed to the lower porosity of the waste caused by higher overburden pressures and higher moisture content of waste in deeper layers of the landfill than in shallow layers. The results suggest that multiple wells screened at different depths provide greater control of air distribution within the landfill. Leachate recirculation was documented to impact the ability to add air. In addition to limitations posed by standing water in many of the deeper wells, waste exposed to leachate recirculation was found to be significantly less permeable to air when compared to original conditions.     

Carbonation of Municipal Solid Waste Incineration Fly Ash and the Impact on Metal Mobility

Fly ash from municipal solid waste incineration (MSWI) is considered as hazardous waste that calls for a robust, reliable, and reasonable treatment technique. This investigation aims to assess the impact of CO2 partial pressure, water addition, time, and temperature on the stabilization of MSWI fly ash with particular emphasis on Pb, Zn, Cd, and Cr. Carbonation and element mobility were studied by applying thermal analysis and leaching assays on fly ash samples treated according to a 24 factorial design. The relationship between the factors and the response variables was evaluated using partial least squares modeling. Chemical equilibrium calculations were performed so as to complement the experimental findings. Decalcification of carbonated fly ash in a typical Swedish landfill was estimated at 0.13?mm?yr?1 Treatment through carbonation reduced the availability of Pb and Zn about 100 times and also the carbonate alkalinity of 7.4?eq?(kg?FS)?1 (FS represents the fixed solids) was remedied successfully. However, shortcomings that need to be resolved are the remobilization of Cr with time and the mobilization of Cd.     

浅谈生活垃圾焚烧发电项目全过程造价控制

针对城市生活垃圾焚烧发电项目,阐述了工程造价控制应自始至终贯穿于工程建设的全过程,并提出基本建设每个阶段相应的对策.     

Municipal Solid Waste Recycling Issues

Municipal solid waste (MSW) recycling targets have been set nationally and in many states. Unfortunately, the definitions of recycling, rates of recycling, and the appropriate components of MSW vary. MSW recycling has been found to be costly for most municipalities compared to landfill disposal. MSW recycling policy should be determined by the cost to the community and to society more generally. In particular, recycling is a good policy only if environmental impacts and the resources used to collect, sort, and recycle a material are less than the environmental impacts and resources needed to provide equivalent virgin material plus the resources needed to dispose of the postconsumer material safely. From a review of the existing economic experience with recycling and an analysis of the environmental benefits (including estimation of external social costs), we find that, for most communities, curbside recycling is only justifiable for some postconsumer waste, such as aluminum and other metals. We argue that alternatives to curbside recycling collection should be explored, including product takeback for products with a toxic content (such as batteries) or product redesign to permit more effective product remanufacture.     

Compaction Characteristics of Municipal Solid Waste

Compaction characteristics of municipal solid waste (MSW) were determined in the laboratory and in the field as a function of moisture content, compactive effort, and seasonal effects. Laboratory tests were conducted on manufactured wastes using modified and 4X modified efforts. Field tests were conducted at a MSW landfill in Michigan on incoming wastes without modifications to size, shape, or composition, using typical operational compaction equipment and procedures. Field tests generally included higher efforts and resulted in higher unit weights at higher water contents than the laboratory tests. Moisture addition to wastes in the field was more effective in winter than in summer due to dry initial conditions and potential thawing and softening of wastes. The measured parameters in the laboratory were γdmax-mod = 5.2?kN/m3, wopt-mod = 65%, γdmax-4×mod = 6.0?kN/m3, and wopt-4×mod = 56%; in the field with effort were γdmax-low = 5.7?kN/m3, wopt-low = 70%; γdmax-high = 8.2?kN/m3, and wopt-high = 73%; and in the field with season were γdmax-cold = 8.2?kN/m3, wcold = 79.5%, γdmax-warm = 6.1?kN/m3, and wwarm = 70.5%. Soil compaction theory was reasonably applicable to wastes with the exception that the Gs of waste solids increased with compactive effort resulting in steep degree of saturation curves and low change in wopt between efforts. Moisture addition to wastes during compaction increased the workability, the unit weight, and the amount of incoming wastes disposed, and reduced the compaction time. The combined effects have significant environmental and economic implications for landfill operations.     

Unit Weight of Municipal Solid Waste

The unit weight of municipal solid waste (MSW) is an important parameter in engineering analyses of landfill performance, but significant uncertainty currently exists regarding its value. A careful review of reliable field data shows that individual landfills have a characteristic MSW unit weight profile. Based on in situ unit weight data and trends observed in large-scale laboratory tests, a hyperbolic relationship was developed to represent this characteristic MSW unit weight profile. Within the context of this characteristic profile, landfill-specific values of MSW unit weight depend primarily on waste composition, operational practices (i.e., compaction, cover soil placement, and liquids management), and confining stress. Guidance is provided for developing landfill-specific MSW unit weight profiles, including procedures for performing large-scale tests for in situ measurement of MSW unit weight at a landfill.     

Shear Strength of Municipal Solid Waste

A comprehensive large-scale laboratory testing program using direct shear (DS), triaxial (TX), and simple shear tests was performed on municipal solid waste (MSW) retrieved from a landfill in the San Francisco Bay area to develop insights about and a framework for interpretation of the shear strength of MSW. Stability analyses of MSW landfills require characterization of the shear strength of MSW. Although MSW is variable and a difficult material to test, its shear strength can be evaluated rationally to develop reasonable estimates. The effects of waste composition, fibrous particle orientation, confining stress, rate of loading, stress path, stress-strain compatibility, and unit weight on the shear strength of MSW were evaluated in the testing program described herein. The results of this testing program indicate that the DS test is appropriate to evaluate the shear strength of MSW along its weakest orientation (i.e., on a plane parallel to the preferred orientation of the larger fibrous particles within MSW). These laboratory results and the results of more than 100 large-scale laboratory tests from other studies indicate that the DS static shear strength of MSW is best characterized by a cohesion of 15?kPa and a friction angle of 36° at normal stress of 1?atm with the friction angle decreasing by 5° for every log cycle increase in normal stress. Other shearing modes that engage the fibrous materials within MSW (e.g., TX) produce higher friction angles. The dynamic shear strength of MSW can be estimated conservatively to be 20% greater than its static strength. These recommendations are based on tests of MSW with a moisture content below its field capacity; therefore, cyclic degradation due to pore pressure generation has not been considered in its development.