垃圾焚烧烟气中二(噁)英零排放技术实践

介绍了绍兴新民热电有限公司用煤和垃圾混烧循环流化床技术处理城市生活垃圾，焚烧烟气经活性炭吸附、半干法和布袋除尘器净化工艺处理后，烟气中二噁英接近零排放。     

垃圾焚烧及烟气净化技术分析

分别阐述了垃圾焚烧系统的类型及烟气净化的系统配置，并以工程实践中的多种烟气净化设备配置为例，分析了这些配置的优缺点。     

The benefits of flue gas recirculation in waste incineration

Flue gas recirculation in the incinerator combustion chamber is an operative technique that offers substantial benefits in managing waste incineration. The advantages that can be obtained are both economic and environmental and are determined by the low flow rate of fumes actually emitted if compared to the flue gas released when recirculation is not conducted. Simulations of two incineration processes, with and without flue gas recirculation, have been carried out by using a commercial flowsheeting simulator. The results of the simulations demonstrate that, from an economic point of view, the proposed technique permits a greater level of energy recovery (up to +3%) and, at the same time, lower investment costs as far as the equipment and machinery constituting the air pollution control section of the plant are concerned. At equal treatment system efficiencies, the environmental benefits stem from the decrease in the emission of atmospheric pollutants. Throughout the paper reference is made to the EC legislation in the field of environmental protection, thus ensuring the general validity in the EU of the foundations laid and conclusions drawn henceforth. A numerical example concerning mercury emission quantifies the reported considerations and illustrates that flue gas recirculation reduces emission of this pollutant by 50%.     

Experimental research on emission and removal of dioxins in flue gas from a co-combustion of MSW and coal incinerator

This paper describes the experimental study of dioxins removal from flue gas from a co-combustion municipal solid waste and coal incinerator by means of a fluidized absorption tower and a fabric filter. A test rig has been set up. The flow rate of flue gas of the test rig is 150-2000 m3/h. The system was composed of a humidification and cooling system, an absorption tower, a demister, a slurry make-up tank, a desilter, a fabric filter and a measurement system. The total height of the absorption tower was 6.5m, and the diameter of the reactor pool was 1.2 m. When the absorbent was 1% limestone slurry, the recirculation ratio was 3, the jet rate was 5-15 m/s and the submerged depth of the bubbling pipe under the slurry was 0.14 m, the removal efficiency for dioxins was 99.35%. The concentration of dioxins in the treated flue gas was 0.1573 x 10(-13)kg/Nm3 and the concentration of oxygen was 11%. This concentration is comparable to the emission standards of other developed countries.     

危险废物焚烧厂烟气净化工艺设计与探讨

参考国内外已有的危险废物焚烧工程相关设计和研究资料,针对国内具有代表性的危险废物成分,采用设计计算得到危险废物焚烧烟气的污染物初始浓度,分析成熟的烟气净化工艺,对适合中国危险废物特点的危险废物焚烧厂烟气净化工艺进行了设计和探讨,为危险废物焚烧厂建设单位及设计单位等提供参考。     

The privatization effect of MSW incineration services by using data envelopment analysis

This paper attempts to compare the relative efficiency across MSW incineration facilities under the three operating modes including government-owned government-operated (GOO), government-owned private-operated (GOPO), and private-owned private-operated (POPO) by using the Data Envelopment Analysis (DEA), and to examine the factor in affecting the efficiency variation. The results show that technical efficiency scores are 0.7538, 0.9046 and 0.9917 for GOO, GOPO and POPO, respectively. An ANOVA is conducted and the analysis result confirms that the operating mode has significant impact on technical efficiencies. A further examination on the operating contracts signed between governments and operating firms of GOPO facilities finds that both the price protection and quantity protection also play vital roles in affecting efficiencies.     

冲灰管炉烟阻垢试验研究及应用

根据火电厂冲灰管道结垢的原因和结垢物的特点，利用虹吸抽气原理将烟气引入灰水，烟气中的二氧化硫、氮氧化物等酸性气体与灰水中碱性成垢物质反应，使灰水的pH值降低。系统的投运，避免了冲灰管道的结垢，同时减少了二氧化硫的外排，具有很好的经济效益和环境效益。     

Mathematical modelling of MSW incineration on a travelling bed

The rising popularity of incineration of municipal solid waste (MSW) calls for detailed mathematical modelling and understanding of the incineration process. In this paper, governing equations for mass, momentum and heat transfer for both solid and gaseous phases in a moving bed in a solid-waste incineration furnace are described and relevant sub-models are presented. The burning rates of volatile hydrocarbons in the moving bed of solids are limited not only by the reaction kinetics but also the mixing of the volatile fuels with the under-fire air. The mixing rate is averaged across a computation cell and correlated to a number of parameters including local void fraction of the bed, gas velocity and a length scale comparable to the particle size in the bed. A correlation equation is also included to calculate the mixing in the freeboard area immediately next to the bed surface. A small-scale fixed bed waste incinerator was built and test runs were made in which total mass loss from the bed, temperature and gas composition at different locations along the bed height were measured. A 2-D bed-modelling program (FLIC) was developed which incorporates the various sub-process models and solves the governing equations for both gases and solids. Thermal and chemical processes are mainly confined within a layer about 5-9 times in thickness of the averaged particle size in the burning bed. For a large part of the burning process, the total mass loss rate was constant until the solid waste was totally dried out and a period of highly rising CO emission followed. The maximum bed temperature was around 1200 K. The whole burning process ended within 60 min. Big fluctuations in species concentration were observed due to channelling and subsequent 'catastrophic' changes in the local bed conditions. Reasonably good agreement between modelling and measurements has been achieved. Yet the modelling work is complicated by the channelling phenomenon in the bed. Numerical simulations without consideration of the channelling effect produced very good agreement with experiments concerning the total mass loss, but significant discrepancy exists for temperature and gas composition profiles. Transient phenomena such as the breaking of waste particles and the "catastrophic" creation of new burning channels occurring during waste incineration is a vital area requiring further investigation at the fundamental level. The underlying theory of bed behaviour must be extended to include these transient events.     

Simulation of the flue gas cleaning system of an RDF incineration power plant

Because of the stringent pollutant emission standards introduced with the European Union guidelines for waste incineration, it is very important to optimize the flue gas cleaning systems which are able to result in a low environmental impact according to the emission limits. In this paper a thermochemical model has been proposed for the simulation of the flue gas cleaning system of an RDF incineration plant. The model simulates the operation of the flue-gas treatment section and the combustion section by using a simplified approach. The combustion includes the grate incinerator and the post-combustion chamber, while the cleaning section includes the NO(x) reduction process (urea injection) and the scrubbing of SO(2) and HCl (Ca(OH)(2) as sorbent). The modelling has been conducted by means of ASPEN PLUS code. The simulation results have been validated with the operating data. The model proposed by the authors can be a useful tool in both evaluating the efficiency of the gas cleaning system by verifying the environmental pollution of an incinerator power plant in nominal operating conditions and in forecasting the efficiency of the cleaning system in off-design operating conditions.     

SO3烟气调质试验研究

介绍了SO3烟气调质技术的原理和现场试验方法，并就烟尘调质中的设备腐蚀问题进行了探讨。上海石洞口电厂2号炉烟气调质试验结果表明。该技术在解决电厂由高硫煤改烧低硫煤时，原电除尘器除尘效率下降的问题有显效，可使除尘效率从98．5％提高到99％以上。     

Adsorption of SO2 and NO from incineration flue gas onto activated carbon fibers

Activated carbon fibers (ACFs) were used to remove SO(2) and NO from incineration flue gas. Three types of ACFs in their origin state and after pretreatment with HNO(3), NaOH, and KOH were investigated. The removal efficiencies of SO(2) and NO were determined experimentally at defined SO(2) and NO concentrations and at temperatures of 150, 200 and 260 degrees C. Experimental results indicated that the removal efficiencies of SO(2) and NO using the original ACFs were <56% and <27%, respectively. All ACFs modified with HNO(3), NaOH, and KOH solution could increase the removal efficiencies of SO(2) and NO. The mesopore volumes and functional groups of ACFs are important in determining the removal of SO(2) and NO. When the mesopore volumes of the ACFs are insufficient for removing SO(2) and NO, the functional groups on the ACFs are not important in determining the removal of SO(2) and NO. On the contrary, the effects of the functional groups on the removal of SO(2) and NO are more important than the mesopore volumes as the amount of mesopores on the ACFs is sufficient to remove SO(2) and NO. Moreover, the removal efficiencies of SO(2) and NO were greatest at 200 degrees C. When the inlet concentration of SO(2) increased to 600ppm, the removal efficiency of SO(2) increased slightly and the removal efficiency of NO decreased.     

平板陶瓷膜回收烟气水热的实验研究

将平板陶瓷膜组成膜组件对烟气水分和余热进行回收,考察了烟气的温度、相对湿度、流速和冷却水温度等参数对膜组件水热回收性能的影响。在实验工况下,水通量和水回收效率随着烟气温度、烟气相对湿度的增加和冷却水温度的降低而上升;水通量随着烟气流速的加快而上升,水回收效率随着烟气流速的加快先上升后降低;膜组件的水通量和水回收效率最高分别可达22.0 kg/(m²·h)和36.3%。平板陶瓷膜回收的热量主要来自烟气潜热,烟气潜热换热量与水通量呈正相关变化趋势。在实验工况下,平板陶瓷膜组件的总传热系数最高为412 W/(m²·℃),高于多通道管式陶瓷膜和单通道管式陶瓷膜。     

Greenhouse gas emissions from MSW incineration in China: Impacts of waste characteristics and energy recovery

Determination of the amount of greenhouse gas (GHG) emitted during municipal solid waste incineration (MSWI) is complex because both contributions and savings of GHGs exist in the process. To identify the critical factors influencing GHG emissions from MSWI in China, a GHG accounting model was established and applied to six Chinese cities located in different regions. The results showed that MSWI in most of the cities was the source of GHGs, with emissions of 25–207 kg CO₂-eq t^?1 rw. Within all process stages, the emission of fossil CO₂ from the combustion of MSW was the main contributor (111–254 kg CO₂-eq t^?1 rw), while the substitution of electricity reduced the GHG emissions by 150–247 kg CO₂-eq t^?1 rw. By affecting the fossil carbon content and the lower heating value of the waste, the contents of plastic and food waste in the MSW were the critical factors influencing GHG emissions of MSWI. Decreasing food waste content in MSW by half will significantly reduce the GHG emissions from MSWI, and such a reduction will convert MSWI in Urumqi and Tianjin from GHG sources to GHG sinks. Comparison of the GHG emissions in the six Chinese cities with those in European countries revealed that higher energy recovery efficiency in Europe induced much greater reductions in GHG emissions. Recovering the excess heat after generation of electricity would be a good measure to convert MSWI in all the six cities evaluated herein into sinks of GHGs.     

Dry scrubbing of municipal solid waste incineration flue gas using porous sodium carbonate produced via vacuum thermal treatment of sodium bicarbonate

Journal of Material Cycles and Waste Management - Sodium bicarbonate is among the alkali chemicals used for dry scrubbing in incineration flue gas treatment. It is generally pulverized into fine...     

燃煤烟气中新型吸附剂改性蛭石研究进展

总结了燃煤烟气中汞污染的现状及蛭石吸附剂研究的进展情况,对烟气中单质汞的脱除进行了研究,提出了蛭石在单质汞的吸附脱除方面存在的潜力,为今后燃煤烟气中单质汞的脱除提出了一定的研究思路.     

湿法脱硫技术关键问题研究

针对我国烟气脱硫存在的实际问题,研究了湿法脱硫关键技术,如多孔板环面积、层数、安装角度、孔径及开孔率,喷淋塔压力降特性等。解决了湿法烟气脱硫过程中关键问题,实现了除雾器的国产化,优化了物料分配技术,降低了脱硫石膏含水率,形成了一整套具有自主知识产权的湿式高性能脱硫技术,并成功应用于多个燃煤电厂商用脱硫工程,取得了显著的经济效益和社会效益。     

Effect of natural ageing on volume stability of MSW and wood waste incineration residues

This paper presents the results of a study on the effect of natural weathering on volume stability of bottom ash (BA) from municipal solid waste (MSW) and wood waste incineration. BA samples were taken at different steps of treatment (fresh, 4 weeks and 12 weeks aged) and then characterised for their chemical and mineralogical composition and for volume stability by means of the mineralogical test method (M HMVA-StB), which is part of the German quality control system for using aggregates in road construction (TL Gestein-StB 04). Changes of mineralogical composition with the proceeding of the weathering treatment were also monitored by leaching tests. At the end of the 12 weeks of treatment, almost all the considered samples resulted to be usable without restrictions in road construction with reference to the test parameter volume stability.     

Removal of mercury from flue gas using sewage sludge-based adsorbents

Mercury from coal-fired utility boilers, as the largest atmospheric mercury emission source, imposes serious environmental risks and health concerns. In order to explore the possibility of reducing costs of activated carbon injection, we investigated the most promising mercury control technology, Hg⁰ removal using ZnCl₂-impregnated adsorbents derived from sewage sludge. The results demonstrated that sludge-based adsorbents (SBAs) had fairly high mercury adsorption capacity over a wide range of temperatures (80–170 °C). Oxidizing atmosphere could improve the adsorption of Hg⁰ and weaken the inhibition of SO₂ on mercury adsorption to some extent. NO exhibited no obvious impact on mercury removal performance. In addition, to clarify whether oxygen- or chlorine-containing functional groups attributed to good mercury adsorption capacity of SBAs, the oxygen-containing functional groups were removed using Boehm’s method, and a temperature-programmed decomposition desorption experiment was conducted. The results suggest that chlorine-containing functional groups played a significant role in the removal process of mercury from flue gas using SBAs.     

湿法脱硫系统事故烟气急冷数值模拟研究

对脱硫系统事故工况下急冷装置下游烟气的流场及温度场分布进行了数值模拟研究和分析,并提出了基于原始喷雾系统布置方案的一种优化方案。该方案在能满足设计要求的前提下,最大限度的减少了喷嘴数量和水耗。在事故急冷装置实际工程设计及应用上,具有一定的理论指导意义。