Rauchgasreinigung mit Reststoffbehandlung und Wertstoffgewinnung in der Abfallverbrennung — Stand und Tendenzen

The design of flue gas treatment equipment in municipal waste incineration plants worldwide varies according to the requirements with respect to pollutant emissions and resource recovery. Various combinations of individual separation processes may be encountered, such as dry particle separation, gas absorption (wet or dry), adsorption, catalytic or thermal conversion. The present comparison of different basic process alternatives indicates that firstly any degree of pollutant removal can be achieved by the available process technologies with corresponding expenditure of money and energy demand, secondly, German plants generally are more complex than plants in other countries due to more stringent separation and resource recovery efficiency requirements, and thirdly, a trend can presently be seen towards more simple and cheaper processes with simultaneous separation of several pollutants in one process step.     

Planung einer Verbrennungsanlage für industrielle Rückstände

Design of an incinerator for industrial waste. For many years rotary kilns have been used in combination with an afterburner chamber followed by a steam boiler at BASF to incinerate the waste of chemical plants. Six incineration lines are available at the moment. As the amount of waste is always increasing an additional incinerator was necessary on increasing the incineration capacity a new flue gas cleaning system would have to be installed, not only for the new incinerator but also for the flue gas of five of the existing furnaces. The cleaning system will be done in two lines, each of them consists of an electric precipitator and a multistage scrubber. In order to design the new incinerator line, not only many operating conditions and legal prerequisites but also constructional and combustion requirements had to be considered. While the design of the rotary kiln is based essentially on empirical coefficients, e. g. on the burning load related to the furnace volume, the design of the afterburner chamber was made by the help of a numerical computation model supported by experimental model investigations. A further focal point was optimizing the operation of the waste burner which gave a primary reduction of the NO_x emission.     

Stand der Emissionsmeßtechnik im Abgas der Rückstandsverbrennung

State of the art of emission measuring techniques in the flue gas of waste incineration plants. It is necessary to critically consider measuring techniques in the light of new requirements for waste incinerators (17th ordinance dating from Dec. 1990). Selected examples are concerned with the primary components of flue gas: particulate matter and trace metals, organics with total carbon content, and important groups such as organochlorine compounds (e.g. dioxins/furans) and inorganic chlorides (such as hydrogen chlorine). The evaluation concludes by considering manual techniques as well as monitoring systems and measures for quality assurance. Finally, an account of recent developments in the monitoring of ammonia and mercury is presented.     

Verbrennungsanlage mit Rauchgaswäsche für die Beseitigung von Chemie-Abfällen

Incineration plant with flue-gas scrubbers for disposal of chemical waste . Incineration plant No. II installed at the Bayer Facilities at Leverkusen/Germany has been in regular operation since November 1977 after a previous one-year period of testing. About 25 000 t of industrial waste per year can be burnt in this plant, simultaneously producing nearly 140 000 t of steam. The plant consists of a bunker building, a rotary kiln and secondary combustion chamber, including all the feeding equipment for solid, viscous, and liquid wastes, as well as a boiler, an electrostatic dust precipitator, and a wet gas cleaning unit. This latter unit consists of an injection cooler (quencher), two rotary scrubbers, and a jet scrubber. The cleaned flue gas is reheated in two heat exchangers and is discharged from a suction blower through a 100 m high chimney into the atmosphere. Around the chimney several measuring instruments are installed to check and continuously record the type and amount of emission. The scrubber water is sent to the company waste water treatment plant; the solid ashes and dust are dumped separately. The average incineration costs are DM 400 per ton of waste.     

垃圾焚烧中抑制二噁英二次生成的方法探讨

根据生活垃圾焚烧技术中二噁英的生成机理,余热锅炉的烟气在低温区急冷可以避免二噁英在低温区的再次合成,但是目前的余热锅炉烟气低温区急冷的不可行,提出从垃圾焚烧系统设计上进行烟气的急冷,抑制二噁英低温区二次生成的新方法。     

Zukunftssichere und umweltneutrale Beseitigung von Industrieabfällen

Low environmental-impact disposal of solid, liquid and semisolid industrial residues . In many production plants, waste residues are formed which must be treated before their disposal so as to safeguard against environmental pollution. Industrial methods for the treatment and disposal of residues are so multifarious that each disposal problem requires careful consideration so as to ensure selection of the most suitable method, both from the ecological and economical point of view. Dumping grounds cannot accommodate all waste materials without endangering or disturbing the environment. For incineration, proven methods are available which can be modified to suit the particular waste problem at hand. After a suitable pretreatment every effort must be made to achieve a waste free from organic materials, an optimum utilization of heat and a flue gas purification without inadmissible loading of waste gases and waters. In recent years there has been a considerable increase in research and development activities in the area of thermal treatment of solid, liquid and semi-solid wastes. Worth mentioning are the high-temperature methods giving favourable emission values and methods for degasification and gasification directed at the recovery of important raw materials. Plants based on these principles are currently being operated on the pilot scale.     

垃圾焚烧系统换热表面的积灰生长与控制研究进展

焚烧是我国处理城市生活垃圾的重要方式，能够实现城市生活垃圾的减量化、无害化和资源化利用。由于城市生活垃圾水分高、盐分多、热值低，导致垃圾焚烧炉普遍面临严重的积灰问题，这不仅为垃圾焚烧炉的安全运行带来隐患，还严重影响垃圾焚烧发电厂的经济效益。本文综述了垃圾焚烧炉受热面积灰生长的研究现状，介绍了垃圾焚烧炉受热面积灰生长的机理，分析了飞灰粒径、烟气流速、烟气温度、换热面温度等对垃圾焚烧炉受热面积灰生长特性产生影响的因素。在燃煤锅炉和生物质炉积灰结渣的现有积灰模型基础上，需要结合垃圾炉的积灰实验数据发展可以预测垃圾焚烧炉积灰结渣问题的模型。针对垃圾焚烧炉受热面积灰严重的现象，本文提出了设备改进、工艺优化、使用添加剂和涂层技术抑制积灰生长的一系列方法。最后总结了当前的重点研究内容，提出了建立能够准确预测垃圾焚烧炉积灰生长的模型，开发新的有效减轻垃圾焚烧炉换热面积灰的涂层等今后开展研究的方向，为垃圾焚烧电厂的合理运行提供了参考建议。     

利用过剩煤气焚烧处理中小型焦化厂的酚氰废水

针对中小焦化厂环保投入不足和焦炉煤气相对过剩的实际情况,提出利用焚烧焦炉煤气来处理焦化废水的新方法。阐述了该方法的原理与工艺流程。对废水处理前后的主要参数指标的检测和对该工艺技术、经济与环境等综合效益的评估及实际运行结果表明,该方法"以废治废"原理可靠,工艺简单,吨水处理成本约为2.55元,可实现焦化废水"零排放",废热回收后尾气可达GB16297-1996一级排放标准。建议在有过剩焦炉煤气的中小焦化厂推广。     

Contribution to solving the problem of dioxins generated during waste incineration

The production of dioxins/furans during waste incineration, and particularly the development of measures for minimizing the amount of generated pollutants, continue to command a considerable scientific as well public interest. Experiments are reported which were performed at the TAMARA municipal solid waste pilot incineration, erected on the premises of the karlsruhe Nuclear Research Centre. These experiments show that the solid waste mass flow rate and moisture content influence the dioxin/furan formation, Good removal efficiencies of dioxins/furans have been In wet cleaning. Hydrogen peroxide added to the crude gas is an interesting “killer” reagent for dioxins/furans.     

固体废物焚烧灰渣毒性评估及其控制方法研究进展

固体废物焚烧产生的灰渣时环境是一种二次污染物,其中,焚烧飞灰因其含有重金属及有毒有机污染物而被列为危险固体废物,因此在其最终处置前,必须进行稳定化处理.作者介绍了灰渣的污染特性,尤其是飞灰中所含重金属、有毒有机污染物的毒性及其各种评估方法,包括水平震荡法、浸出柱实验法、毒性浸出程序(TCLP),并综述了当前灰渣的控制技术方法和资源化利用手段,如水泥固化法、熔融固化法、化学药剂固化法.     

垃圾焚烧飞灰在污染物控制领域中的应用探讨

随着垃圾焚烧处置技术的推广和应用,垃圾焚烧飞灰产量逐年增加,传统填埋处置方式存在成本高、填埋场资源不足等问题,因此飞灰的综合利用问题广受关注。由于飞灰富含SiO₂、Al₂O₃等活性物质,在污染物的吸附脱除领域具有良好的应用前景。本文主要结合垃圾焚烧飞灰的理化特性,介绍了垃圾焚烧飞灰在不同废水废气中的污染物吸附脱除效果。综合近年来污染物脱除研究情况,着重介绍了原始飞灰和改性飞灰在重金属、磷盐、染料等污染物脱除中的应用效果、机理,指出了目前存在的主要问题,并对不同的应用工艺进行了成本分析和优缺点对比。最后提出了需要继续深入微波水热在提高飞灰吸附性的应用研究和进一步完善飞灰在污染物控制领域应用的全过程研究的建议与展望。     

城市垃圾焚烧发电污染物处理技术

城市垃圾焚烧发电以其具有明显的减量化、无菌化、资源化等优点,近年来得到了较广泛的应用。然而,垃圾焚烧后产生的酸性气体、二噁英、灰渣及废水等,如果处理处置不慎就会对环境产生二次污染。文章概述了酸性气体、二噁英、灰渣及废水等垃圾焚烧二次污染物的形成机理,并详细介绍了控制垃圾焚烧所产生二次污染物的方法与措施。     

Verhalten von (Schwer-) Metallen bei der Verbrennung kommunaler Abfälle

Behaviour of (heavy) metals on incineration of municipal wastes. Incineration technology is being used to a growing extent for the disposal of municipal wastes. In order to make this technology less harmful to the environment, steps must be taken to counteract the emission of HCl and SO₂ and NO_x as well as of some metals, above all mercury. For this purpose the pollutant inventory must be known more reliably than was previously the case. Care must also be taken that the problems connected with pollutants are not merely transposed from the air to water or solids. If necessary, the fractions that are soluble in a slightly acid medium must be removed from the fly ash, reacted chemically, and immobilized as compact materials. The actual incineration must be performed in such a way that inert slag is formed so that reusability is assured. The slag may also have to undergo chemical treatment.     

Emission of Polycyclic Aromatic Hydrocarbons (PAH) from Solid Waste Incinerator Equipped with an After-Combustion Chamber

Abstract

Polycyclic aromatic hydrocarbons (PAH) are typical indicators of incomplete combustion during solid waste incineration. The PAH emissions caused by waste incineration vary according to waste composition and operating parameters such as furnace temperature, after-combustion conditions, excess air, carbon monoxide levels.

In this work, the content of PAH in the fly ashes (sampled upstream the flue gas treatment system) and bottom ashes produced by the combustion of a refuse derived fuel (RDF) in a rotary kiln incinerator equipped with an after-combustion chamber is determined. The emission levels of PAH are correlated with different operating conditions of the incinerator to evaluate the destruction efficiency of the after-combustion chamber for these compounds.     

Abscheidung und Messung sehr feiner flüssiger und fester Partikeln in der chemischen Industrie

Separation and measurement of very fine liquid and solid particles in the chemical industry. In comparison to power stations, the total amounts of waste gases emitted by the chemical industry are fairly low. On the other hand, the complexity of the waste gases and their components is far higher. In the chemical industry we can therefore not be content with one overal concept for gas purification, but must use a multitude of individual solutions. These should be applied at source, i.e. to each separate production plant. To solve an aerosol separation problem successfully and economically, a knowledge of the composition, the fineness and the amount of aerosols is essential. Cascade impactors have proved to be the most suitable instruments for a fractionated measurement of solid and liquid particulates in the super and sub-micron size range. The results of these measurements make is possible to choose the right equipment and to calculate its performance. Very complex aerosols, e.g. aerosols which are composed both of liquid and solid particles, or of sticky particles, are likely to present the most difficult problems. This article deals with a small selection of cases by demonstrating the problems of separation and the different ways of solving them. It considers among others acid mists and oil mists as well as organic mists, together with very fine particulates from waste incineration plants.     

Prediction of gaseous pollutants and heavy metals during fluidized bed incineration of dye sludge

This research provides an equilibrium model for predicting both the emission of gaseous pollutants and the fate of heavy metals during incineration of biologically treated dye sludge in a bench-scale fluidized bed incinerator. Major gaseous pollutants and hazardous trace heavy metals have been also measured under various operating conditions. The predicted values, which were derived by using a thermodynamic equilibrium model, can be used to determine the optimum operating parameters and the risk associated with hazardous waste incineration by means of verifying experimental data. However, prediction of NO_x emission using a thermodynamic equilibrium model during incineration of waste was not simple. The reason is that the variation of NO_x emission during incineration of waste was affected by the various operating parameters, such as air-fuel ratio(λ _T ), primary air factor(λ ₁ /λ _T ), combustor geometry, method of heat release, and preheating of combustion air. According to the distributions of Cr and Pb simulated by the equilibrium model, all of the Cr in the feed was retained in the ash as the solid phase of Cr₂CO₃. However, most Pb was retained in the ash during incineration as the solid phase of PbSO₄, or heterogeneously deposited onto the fly ash as PbO(g) when the combustion gas becomes cool. Presented at the Int’/Sym. on Chem. Eng. (Cheju, Feb. 8–10, 2001), dedicated to Prof. H. S. Chun on the occasion of his retirement from Korea University.     

基于测试数据的蔗渣锅炉能量分析及能效提升措施

目前蔗渣锅炉存在服役年限较长、燃烧不充分、效率低下、燃料浪费严重以及污染物排放高等问题,对其原因分析欠缺大量现场数据。为了解决这一问题,本文对121台蔗渣锅炉进行能效测试,得出锅炉热效率达到标准限定值和目标值的数量分别仅占51.24%和0.83%;热损失最大的排烟热损失达10%,其中所含水分的热损失占到将近1/4;二氧化碳排放量平均值达到131.54kg/GJ。深入分析各影响因素与热效率的关系,得出了主要影响因素为烟气温度、过量空气系数和飞灰含碳量。并针对这些因素提出了能效提升措施。若能效均能达到限定值或目标值,每年的蔗渣消耗量将分别减少157kt或568kt,二氧化碳排放量将分别减少160kt或522kt,其他污染物排放同样会减少,推及到全国的蔗渣锅炉,节能减排潜力更巨大。     

中国燃煤电厂脱硫废水处理技术研究进展及标准修订建议

目前国内外近7成的火电厂都采用石灰石-石膏湿法烟气脱硫,该法产生的脱硫废水成分复杂难以处理,是当前电力环保面临的难题;同时,随着国家环保节能法律法规的日趋严格,废水零排放技术将会上升到技术规范层面高度。燃煤电厂作为用水大户,除了耗水惊人,锅炉、循环水系统、环保单元等系统出水的水量和水质都值得进一步研究,同时考虑到相关排放标准DL/T 997—2006《石灰石-石膏湿法脱硫废水水质控制指标》尚待完善,建议依据现有污废水处理技术给出科学合理的控制标准,例如通过借鉴国外发达国家基本趋于成熟的污染物排放标准体系,从浓度控制向总量控制过渡。笔者综述了我国燃煤电厂石灰石-石膏湿法脱硫废水处理技术研究进展,脱硫废水的水质特点和污染物来源等问题,归纳总结了国内外污废水排放相关控制标准以及标准制定过程中的重难点,认为应该控制脱硫废水总溶解性固体TDS(尤其是氯离子)、重金属离子等污染物指标。由此,电力行业燃煤电厂脱硫废水的排放标准需要与时俱进,积极响应国家"十三五"计划,进一步规范和促进工业废水排放技术的发展,逐步改善我国的水环境。     

危险废物焚烧的烟气污染物的控制和净化探讨

危险废物焚烧产生的烟气包括卤化物、硫的氧化物、氮氧化物、重金属、二恶英等。如何处理这些危险废物焚烧产物,达到欧盟EU/2000/76/EC排放标准是本项目的关键。     

Fortschritte bei der Abscheidung von Stäuben im Elektrofilter unter Berücksichtigung der Schadgas-Adsorption

Progress in dust collection by electrostatic precipitators with due attention to adsorption of noxious gases . It is shown on the basis of the present state of the art that the stipulations of the pollution control legislation for large boilers can be met by electrostatic precipitators and that fine dust and heavy metals are collected to a sufficiently high degree. Recent developments are dealt with which bring about a fundamental improvement of the collection in the precipitator. Noxious gases have to be separated together with the dust to an ever-increasing extent. With dry processes, fluidized beds are arranged upstream of the electrostatic precipitator for the adsorption of, for instance, HCl, HF, and SO₂. In these cases the dusts will be highly concentrated and of varying chemical composition. Dry gas cleaning in the expanded, circulating fluidized bed downstream of refuse incineration plants and defluorination of waste gases from aluminium electrolysis are considered as examples. The separation of dust under difficult conditions is then dealt with.