循环流化床锅炉燃烧城市生活垃圾的研究进展

城市生活垃圾（MSW）产量的与日俱增及环保要求的不断提高，使循环流化床（CFB）燃烧技术逐渐在MSW的回收和利用方面扮演越来越重要的角色。简要分析了国内外采用分类回收及综合利用、卫生填埋、堆肥和一般焚烧方法处理MSW的不足之处以及采用CFB燃烧技术的优越性，重点介绍了国内外采用CFB燃烧装置焚烧MSW的研究和应用现状，指出了目前存在的问题及努力的方向。采用CFB燃烧装置焚烧MSW关于SO２、NOx、CO排放的实验研究和运行结果令人满意，但对HCl、二恶英及重金属排放还需要进一步研究。试验及实际运行结果都表明，采用CFB燃烧装置对MSW进行焚烧处理是切实可行的，它将是未来解决MSW问题的重要手段。     

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。     

城市下水污泥焚烧过程中二次污染物排放特性的试验研究

在0.15 MWt循环流化床燃烧试验台上进行了城市下水污泥与煤的混烧试验,分析了烟气中的二次污染物排放特性.分析结果表明,利用循环流化床焚烧城市下水污泥时,添加辅助燃料(如煤)及改变焚烧条件,不仅可以达到稳定燃烧的目的,而且有利于抑制焚烧中二次污染物(如CO及二恶英等有机污染物)的生成.分析了焚烧污泥污染物的排放特性,为采用焚烧方式处理城市下水污泥提供了基础性试验数据.     

欧洲MSW的焚烧处理

通过大量资料,对瑞士、西德、挪威、瑞典、丹麦等国MSW处理工艺的现状分析,可见焚烧技术已占优势,而未加处理的填埋正日趋减少。据丹麦有关方面研究,认为应先进行物质回收,而后再焚烧回收热能;应根据能量回收、环境效益、经济效益来评价焚烧工艺。挪     

危险废物回转式流化冷渣多段焚烧系统焚烧特性研究

危险废物的处理和处置是摆在我国各级市政府面前的紧迫任务。然而我国已经运行的危险废物焚烧装置普遍存在回转窑挂壁结渣、热灼减率偏高和污染排放超标等问题,作者通过将回转窑和流化床特点相结合的方法提出了一种新型危险废物回转式流化冷渣多段焚烧处置装置。该装置采用回转窑(一燃室)、二燃室和流化床结合的热解-流化焚烧工艺,特别是采用控制窑头温度避免了回转窑挂壁结渣;采用流化冷渣装置延长未燃烬渣的焚烧时间,解决了热灼减率偏高问题;水冷式烟气急冷装置可以将烟气温度从1 100℃降到200℃,防止了二恶英的尾部低温再生成。该系统运行稳定可靠,可以处理医疗垃圾和大多数的固态和液态危险废物,实现了烟气污染物尤其是二恶英排放达到国家标准的目标。同时对该系统运行时窑头温度分布、二燃室炉膛出口氧量变化、回转窑和炉膛升温特性、燃烧室外壁温度分布等几方面运行数据都进行了详细的介绍,为危险废物焚烧炉的运行提供了宝贵的经验数据。     

氧富集技术用于污泥和固体废物焚烧

美国宾州Allen Town的空气产品公司开发了一种新的氧富集技术.采用这种技术,可在现有废料转化热能的焚烧工厂装置中将生活污水污泥和城市固体废物共同焚化,而对工厂只需作微小改革,而其燃烧状况和气体排放均无变化,故无需重新更换执照.实验室试验已证实如果燃烧气中氧富集量达27%(通常空气中含氧21%),则20%以上的脱水污泥和城市固体垃圾焚烧时,不会感到含酸气体排放量增加.该公司发言人期望该     

长株潭区域生物质开放燃烧的大气污染物排放清单及不确定性分析

根据2012年长株潭区域生物质产量及露天焚烧数据,结合排放因子,估算了长株潭区域生物质开放燃烧所排放的大气污染物量,建立了2012年长株潭区域生物质开放燃烧大气污染物排放清单。结果表明,2012年长株潭区域生物质开放燃烧源SO_2、NO_X、PM_(10)、PM_(2.5)、挥发性有机物(VOCs)、CO、元素碳(EC)、有机碳(OC)排放量分别为783.48、4 248.00、10 325.94、10 117.29、6 882.92、76 002.99、816.09、3 478.28t。秸秆露天焚烧大气污染物排放量在7、10月形成2个峰值,森林火灾集中出现在夏、秋季。生物质开放燃烧污染物排放量最大的县区为长沙市宁乡县,其次为湘潭市湘潭县和长沙市浏阳县。在长株潭中心区域(长沙市开福区、湘潭市岳塘区、株洲市石峰区、荷塘区和芦淞区等城市区域)形成一片污染物排放量较小的区域。采用蒙特卡罗法,计算得到区域秸秆露天焚烧源和森林火灾大气污染物排放量95%置信区间的不确定性分别为-84%~168%、-83%~176%。通过定量模拟得到秸秆露天焚烧PM2.5排放量概率密度函数呈对数正态分布。以PM2.5为代表污染物,对其排放量的不确定性贡献率最大的是露天焚烧比例,燃烧效率、水稻产量、水稻草谷比等也是不确定性的重要来源。     

控制燃油锅炉运行中NOx生成的技术研究

分析燃油锅炉运行中NOx产生的机理,探讨影响其生成的因素,研究抑制其生成和排放的燃烧技术低氧燃烧、掺水燃烧、空气分级燃烧和废气循环燃烧等.结合实验研究结果,重点分析空气分级燃烧和废气循环燃烧对油燃烧中燃料氮转化和氮氧化物生成的影响,并介绍一种新型低氮氧化物排放的燃油技术--预蒸发燃烧技术.     

燃煤锅炉脱汞技术研究进展

燃煤锅炉是主要的烟气汞排放源,汞大多存在于亚微米级颗粒中,其对环境和人类造成的影响不容忽视。综述了现阶段燃煤锅炉汞排放控制技术的研究进展,并对各项技术的脱汞效率、影响因素、投资成本、优缺点及应用可行性进行了分析比较。分析表明,利用现有污染物控制设备(除尘装置、脱硝装置、脱硫装置)协同脱汞比较经济有效,也是当前研究的重点;洗煤技术、燃烧方式的改进和添加燃烧附加物可作为辅助措施使用。     

模拟陈腐垃圾掺烧过程中P/Cl/S对6种重金属迁移特性的影响

通过管式炉焚烧实验,探究了在陈腐垃圾与城市生活垃圾(MSW)掺烧过程中,P/Cl/S对6种重金属(Cd、Zn、Ni、Cu、Cr、Pb)迁移规律的影响,并考察了陈腐垃圾掺混比例、含特征元素的添加剂种类及焚烧温度对6种重金属挥发率的影响.结果 表明,当陈腐垃圾掺烧比例与温度相同时,NaH2PO4和Na2SO4的协同作用对C...     

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     

Control of mercury emissions from a municipal solid waste incinerator in Japan

The control of Hg emissions from a municipal solid waste incinerator (MSWI) is very important, because more than 78% of municipal solid waste (MSW) is incinerated. The Hg content of coal used in utility boilers is relatively low in Japan. In this study, recent trends in the Hg content of MSW in Japan and activated carbon (AC) injection as a control technology of Hg emission from an MSWI are discussed. The effect of AC injection on Hg removal from flue gas in an MSWI was investigated by pilot-scale experiments using a bag filter (BF). The injection of AC increases the Hg reduction ratio by 20-30% compared with cases without AC injection. The Hg reduction ratio increases as the flue gas temperature decreases. The Hg reduction ratio is closely related to the inlet Hg concentration and was expressed with a Langmuir-type adsorption isotherm.     

Control of Mercury Emissions from a Municipal Solid Waste Incinerator in Japan

Abstract

The control of Hg emissions from a municipal solid waste incinerator (MSWI) is very important, because more than 78% of municipal solid waste (MSW) is incinerated. The Hg content of coal used in utility boilers is relatively low in Japan. In this study, recent trends in the Hg content of MSW in Japan and activated carbon (AC) injection as a control technology of Hg emission from an MSWI are discussed. The effect of AC injection on Hg removal from flue gas in an MSWI was investigated by pilot-scale experiments using a bag filter (BF). The injection of AC increases the Hg reduction ratio by 20–30% compared with cases without AC injection. The Hg reduction ratio increases as the flue gas temperature decreases. The Hg reduction ratio is closely related to the inlet Hg concentration and was expressed with a Langmuir-type adsorption isotherm.     

循环流化床锅炉低NOx燃烧环保改造

循环流化床锅炉具有低NOx燃烧的特性,但随着环保要求的不断提高,大部分此种类型锅炉已不能满足现行排放标准,需对原锅炉进行改造。考虑到循环流化床锅炉的结构特点,不适宜进行SCR改造,采用SNCR工艺需具备相应的温度窗口,并且增加还原剂的物料消耗,因此,利用循环流化床炉自身的特点进行局部改造,达到低NOx燃烧的目的,成为一种经济的研究方向。根据某循环流化床锅炉的改造实例探讨具体改造方案及最终效果,提出一种有效的循环流化床锅炉低NOx改造思路。     

回转窑式纯氧熔融焚烧垃圾技术研究

生活垃圾安全无害化处理是目前迫切需要解决的问题,直接气化熔融焚烧垃圾技术以降低二恶英排放方面巨大优势得到广泛关注,在此基础上提出纯氧熔融焚烧垃圾技术,几乎可以实现所有二次污染物近零排放。以350 t/d回转窑垃圾焚烧炉为例,对纯氧代替空气应用在回转窑上熔融焚烧垃圾系统进行了详细热力计算及分析。结果表明,纯氧熔融焚烧垃圾系统的锅炉效率可达90.56%,回转窑熔融焚烧系统还可以在垃圾焚烧后灰渣达到熔融温度的条件下,保持该系统热量平衡,稳定燃烧。并参考回转窑设计标准对该纯氧熔融焚烧城市生活垃圾的回转窑参数进行确定。     

城市生活垃圾并流竖炉焚烧模拟实验研究

气化熔融焚烧技术能够避免重金属和二恶英的二次污染,被公认为实现零排放和环境友好型的焚烧方法。在这样的背景下提出了生活垃圾并流竖炉气化熔融焚烧工艺。该工艺以竖炉为气化熔融主体设备,垃圾料层与助燃空气在炉内都是至上而下并流流动,从而使垃圾热解气化产生的可燃气体在竖炉下部完全燃烧,以提供灰渣熔融耗热。并流竖炉热态模拟试验表明,并流时垃圾料层中各点的温度明显高于逆流情况,并流时产生的CO₂量明显高于逆流情况。因此说并流竖炉更适合气化熔融焚烧工艺的要求。     

Curbing dioxin emissions from municipal solid waste incineration in China: Re-thinking about management policies and practices

As one of the countries with large amounts of dioxin releases, the control of dioxins is a major challenge for China. Municipal solid waste (MSW) incineration should be considered a high priority source of dioxin emissions because it is playing an increasingly more important role in waste management. MSW incineration in China has much higher emission rates of dioxins than in the developed countries, partially resulting from the gaps in the technologies of incineration and flue gas cleaning. Moreover, the current management policies and practices also contribute significantly to the problem. We recommend lowering dioxin emission standard, strengthening fly ash management, and improving regulation enforcement to reduce dioxin releases into the environment from MSW incineration. We also propose that alternative strategies should be considered on dioxin control and call for an expansion of economic instruments in waste management to reduce waste generation and thus the need for incineration.     

150t/d循环流化床生活垃圾焚烧炉的工艺结构与污染排放

垃圾焚烧处理技术在我国的应用越来越广泛 ,单纯引进国外的垃圾焚烧处理技术已经无法满足我国经济发展的需要。清华大学自主开发研制的 15 0t/d循环流化床生活垃圾焚烧炉已经通过专家鉴定 ,各项焚烧污染物排放指标均达到或优于国家标准 ,总体水平居国内领先水平。本文详细介绍了该焚烧炉的系统及结构 ,并对有关控制污染物排放的技术手段进行了详细分析     

An economic evaluation and assessment of environmental impact of the municipal solid waste management system for Taichung City in Taiwan

Municipal solid waste management (MSWM) is an important environmental challenge and subject in urban planning. For sustainable MSWM strategies, the critical management factors to be considered include not only economic efficiency of MSW treatment but also life-cycle assessment of the environmental impact. This paper employed linear programming technique to establish optimal MSWM strategies considering economic efficiency and the air pollutant emissions during the life cycle of a MSWM system, and investigated the correlations between the economical optimization and pollutant emissions. A case study based on real-world MSW operating parameters in Taichung City is also presented. The results showed that the costs, benefits, streams of MSW, and throughputs of incinerators and landfills will be affected if pollution emission reductions are implemented in the MSWM strategies. In addition, the quantity of particulate matter is the best pollutant indicator for the MSWM system performance of emission reduction. In particular this model will assist the decision maker in drawing up a friendly MSWM strategy for Taichung City in Taiwan. Implications: Recently, life-cycle assessments of municipal solid waste management (MSWM) strategies have been given more considerations. However, what seems to be lacking is the consideration of economic factors and environmental impacts simultaneously. This work analyzed real-world data to establish optimal MSWM strategies considering economic efficiency and the air pollutant emissions during the life cycle of the MSWM system. The results indicated that the consideration of environmental impacts will affect the costs, benefits, streams of MSW, and throughputs of incinerators and landfills. This work is relevant to public discussion and may establish useful guidelines for the MSWM policies.     

Remedial strategies for municipal solid waste management in China

The purpose of this investigation is to evaluate the current status and to identify the problems of municipal solid waste (MSW) management in China to determine appropriate remedial strategies. This is the second of two papers proposed on this topic. Major problems or difficulties identified in MSW management in China include MSW land, air, and water pollution, commingled collection, poor administration, shortage of funds, lack of facilities, and problems of training and public awareness. In order to solve these problems and to improve MSW management in China, remedial strategies in three areas are recommended: institutional reform, technology development, and legislation and administrative improvement. The primary principle involved in institutional reform is unifying legislative responsibilities into one body and developing a market mechanism for handling MSW. Composting, landfills, and incineration should be equally developed in accordance with China's needs. The feasibility of developing technology to handle MSW in China is discussed. Also recommended is the establishment of sound regulatory systems, including a service fee system, a source separation system, and a training program. China is presently undergoing economic and institutional reform at the national and local levels. Results of this study will provide useful information on MSW management in China.