Incineration and gasification technologies completed with up-to-date off-gas cleaning system for meeting environmental limits

It is shown how gasification can be used for processing wastes including “waste to energy” system. First, an analysis of incineration of wastes taking into account environmental limits is performed. This analysis is aimed at a typical arrangement of a conventional oxidizing incineration plant consisting of waste storage and feeding systems, two-stage incinerator (primary and secondary combustion chambers), heat recovery system involving co-generation and off-gas cleaning system. It is also focused on a new arrangement where the primary combustion chamber (rotary kiln) is substituted by gasification reactor. The proposed concept with a fluidised bed reactor utilizes results of experimental research with various mixtures of wastes (e.g. shredded textile and rubber) considering typical conditions of operation. Experiments provide us with various important characteristics (heat value of produced syngas vs. temperature in the gasification reactor, temperature in the secondary combustion chamber vs. oxygen concentration in outlet flue gas and heat value of syngas, etc.). Then it is possible to make a comparison of conventional incineration and gasification for a concrete industrial process involving a unit for thermal treatment of hazardous industrial waste mixed with municipal solid wastes with capacity of 10,000 t/year. The application of gasification technology brings about the whole range of benefits like minimizing the consumption of auxiliary fuel and decreasing size of the secondary combustion chamber and other subsystems of the incineration plants. Involving such a system with energy and investment cost reduction into an industrial process contributes to meeting cleaner production and environmental legislation regulations.     

Waste incineration with production of clean and reliable energy

Discussion about utilization of waste for energy production (waste-to-energy, WTE) has moved on to next development phase. Waste fired power plants are discussed and investigated. These facilities focus on electricity production whereas heat supply is diminished and operations are not limited by insufficient heat demand. Present results of simulation prove that increase of net electrical efficiency above 20% for units processing 100 kt/year (the most common ones) is problematic and tightly bound with increased investments. Very low useful heat production in Rankine-cycle based cogeneration system with standard steam parameters leads to ineffective utilization of energy. This is documented in this article with the help of newly developed methodology based on primary energy savings evaluation. This approach is confronted with common method for energy recovery efficiency evaluation required by EU legislation (Energy Efficiency—R1 Criteria). New term highly-efficient WTE is proposed and condition under which is the incinerator classified as highly efficient are specified and analyzed. Once sole electricity production is compelled by limited local heat demand, application of non-conventional arrangements is highly beneficial to secure effective energy utilization. In the paper a system where municipal solid waste incinerator is integrated with combined gas–steam cycle is evaluated in the same manner.     

Waste-to-energy is compatible and complementary with recycling in the circular economy

Clean Technologies and Environmental Policy - This paper reviews the role of conventional waste-to-energy, i.e. incineration of (mainly) municipal solid waste with energy recovery, in the circular...     

DCCHP排烟余热耦合空气源热泵系统性能分析

内燃机冷热电联供系统作为一种高效的能源利用方式,排烟余热回收后的排放温度在100℃左右,仍有部分低温余热没有充分利用,提出一种分布式冷热电三联供（distributed combined cooling heating and power,DCCHP）动力排烟低温余热耦合空气源热泵系统,实现了排烟余热的深度回收。以10 kW内燃机冷热电联供为基础,研究了该系统可回收余热量、热泵循环性能系数（coefficient of performance,COP）以及对一次能源利用率的影响。结果表明：在设计工况下,DCCHP系统排烟余热1.22 kW,热泵系统回收余热量可达1.07 kW,排烟余热回收率达到87.7%;热泵COP高达4.66,提高39.5%;系统一次能源利用率提高3.9%;同时解决了寒冷地区冬季热泵机组蒸发器结霜、低温环境下运行性能差的问题。此研究为冷热电联供系统与热泵机组的联合高效应用提供了重要的参考。     

电站锅炉烟气余热利用技术方案研究

超临界电站锅炉排烟热损失量很大,对锅炉尾部烟气余热进行回收利用可以有效提高电厂的热经济性,减少煤耗,降低环境污染。目前火电厂最广泛提高烟气余热利用效率的方式是加装低温省煤器装置。对某超临界机组锅炉余热利用技术进行研究,分析不同低温省煤器布置方案,提出采用双级低温省煤器回收电站锅炉余热利用技术方案,即采用低温烟气与低加凝结水换热技术、前置式空气预热器与低温省煤器组合的能源梯级利用方式,实现最优节能及最佳投资收益。     

Logistic model-based tool for policy-making towards sustainable waste management

The aim of this paper is to introduce a novel approach which supports facility planning in the field of waste management. Only 23 % of municipal solid waste (MSW) was thermally treated in the EU 27 in 2011. The increased exploitation of its potential for energy recovery must be accompanied by massive investments into highly efficient and reliable incineration technologies. Therefore, the challenge is to be efficient and use the technology to its optimal level. Feasibility studies of all plants providing a service for a region create a large and complex task. Gate fee (the charge for waste processing in the facility) represents one of the most crucial input parameters for the assessment. The gate fee is driven by configuration of the technology, competition, market development, environmental taxation and costs of waste transport to satisfy the plant’s capacity. Valid prediction of the gate fee thus presents a demanding task. In this paper, first, an advanced tool called NERUDA is introduced, which addresses logistic optimization and capacity sizing. The key idea is to focus on the problem of competition modelling among waste-to-energy plants, landfill sites, and mechanical–biological treatment plants producing refuse-derived fuel. Then, the main theoretical concepts are discussed, followed by the development of a suitable mathematical model. The goal is to obtain a minimized cost of MSW treatment for waste producers (municipalities). The application of the developed tool is demonstrated through a case study, where uncertain parameters entering the calculation are handled by a repetitive Monte Carlo simulation based on real-world data.     

125MW热电联产湿冷机组带吸收式热泵试验研究

针对带吸收式热泵回收利用循环水余热供热的125MW热电联产湿冷机组进行性能试验,并分析其运行经济性.试验结果表明当全厂发电功率为204.46MW,采暖供热量为221.83MW,其中热泵回收的余热量为49.73MW,全厂试验供电煤耗率为276.0g/kWh.若回收的循环水余热量用于新增市政供热,则与单纯抽汽供热工况相比,供电煤耗率下降33.8g/kWh;若回收循环水余热量排挤原抽汽供热即供热面积一定时,与单纯抽汽供热工况相比,供电煤耗率下降7.3g/kWh.     

Steel mill slags energy potential: the case of the steel factory of Arcelor-Mittal in Asturias (Spain)

Slag accounts for most of the residuals or by-products of the steel manufacturing process and represents a not inconsiderable amount of energy waste and CO₂ emissions. Energy recovery from steel mill slags is not actually performed because of the difficulty of the industrial implementation, but the actual demand and the incentives for new electricity generation plants based on renewable energies and on industrial waste heat recovery offer a new opportunity to evaluate the feasibility of this process. This article presents a review of the slag energy potential on a global scale, and a proposal for a recovery plant in the factories of Arcelor-Mittal in Asturias (Spain), based on a steam Rankine cycle for electricity production in a turbine. The plant production and viability have been analyzed using the typical technical and economic values for this kind of plant. Also, a parametric study has been performed on the heat recuperator efficiency and investment rate.     

Automotive shredder residue (ASR): reviewing its production from end-of-life vehicles (ELVs) and its recycling, energy or chemicals' valorisation

ASR is in Europe classified as hazardous waste. Both the stringent landfill legislation and the objectives/legislation related to ELV treatment of various countries, will limit current landfilling practice and impose an increased efficiency of the recovery and recycling of ELVs. The present paper situates ASR within the ELV context. Primary recovery techniques recycle up to 75% of the ELV components; the remaining 25% is called ASR. Characteristics of ASR and possible upgrading by secondary recovery techniques are reviewed. The latter techniques can produce a fuel- or fillergrade ASR, however with limitations as discussed. A further reduction of ASR to be disposed of calls upon (co-)incineration or the use of thermo-chemical processes, such as pyrolysis or gasification. The application in waste-to-energy plants, in cement kilns or in metallurgical processes is possible, with attention to the possible environmental impact: research into these impacts is discussed in detail. Pyrolysis and gasification are emerging technologies: although the sole use of ASR is debatable, its mixing with other waste streams is gradually being applied in commercial processes. The environmental impacts of the processes are acceptable, but more supporting data are needed and the advantage over (co-)incineration remains to be proven.     

Ash deposit characterisation in a large-scale municipal waste-to-energy incineration plant

The deposition of ash - combustion residues - on superheaters and heat exchanger surfaces reduce their efficiency; this phenomenon was investigated for a large-scale waste-to-energy incineration facility. Over a period of six months, ash samples were collected from the plant, which included the bottom ash and deposits from the superheater, as well as flyash from the convective heat exchanger, the economiser and fabric filters. These were analysed for particle size, unburned carbon, elemental composition and surface morphology. Element partitioning was evident in the different combustion residues, as volatile metals, such as cadmium, antimony and arsenic, were found to be depleted in the bottom ash by the high combustion temperatures (1000+°C) and concentrated/enriched in the fabric filter ash (transferred by evaporation). Non-volatile elements by contrast were distributed equally in all locations (transported by particle entrainment). The heat exchanger deposits and fabric filter ash had elevated levels of alkali metals. 82% of flyash particles from the fabric filter were in the submicron range.     

Gaseous emissions from waste combustion

An overview is given on methods and technologies for limiting the gaseous emissions from waste combustion. With the guideline 2000/76/EC recent European legislation has set stringent limits not only for the mono-combustion of waste in specialized incineration plants but also for co-combustion in coal-fired power plants. With increased awareness of environmental issues and stepwise decrease of emission limits and inclusion of more and more substances into the network of regulations a multitude of emission abatement methods and technologies have been developed over the last decades. The result is the state-of-the-art waste incinerator with a number of specialized process steps for the individual components in the flue gas. The present work highlights some new developments which can be summarized under the common goal of reducing the costs of flue gas treatment by applying systems which combine the treatment of several noxious substances in one reactor or by taking new, simpler routes instead of the previously used complicated ones or - in the case of flue gas desulphurisation - by reducing the amount of limestone consumption. Cost reduction is also the driving force for new processes of conditioning of nonhomogenous waste before combustion. Pyrolysis or gasification is used for chemical conditioning whereas physical conditioning means comminution, classification and sorting processes. Conditioning yields a fuel which can be used in power plants either as a co-fuel or a mono-fuel and which will burn there under much better controlled conditions and therefore with less emissions than the nonhomogeneous waste in a conventional waste incinerator. Also for cost reasons, co-combustion of wastes in coal-fired power stations is strongly pressing into the market. Recent investigations reveal that the co-firing of waste can also have beneficial effects on the operating behavior of the boiler and on the gaseous emissions.     

Waste-to-energy technologies in continuous process industries

A range of new waste-to-energy (WtE) technologies in continuous process industries have been analyzed in terms of conversion, energy saving, heat recovery, electricity generation, transportation fuel, storing energy and fuel, environmental emissions, and recycling management. This new group of WtE technologies is an emerging technology group for energy-intensive industries apart from the wide concept of “clean energy technologies”. The current state of WtE technologies has been examined for five representative sectors in continuous industrial processes: iron and steel, cement, primary aluminum production, metal casting, and glass industry. The purpose of the study was to seek synergetic interactions between continuous process industries, with special emphasis on the case of the iron and steel industry. For the purpose of a comparative analysis, waste heat recovery (WHR) technology has been included. A case study in the steel sector is illustrated as a real-world example for solid recovery using WHR in sintering process.     

工业厂房大型组合式空调系统节能方案探讨

介绍工业厂房组合式空调机组的组成和空调系统的形式,重点阐述降低能耗的措施,根据工厂特点设计余热利用方案,并介绍余热利用工程设计中应注意的问题.     

基于收益分享合同的垃圾源头分类激励机制

通过建立两阶段的Stackelberg动态博弈模型,研究了固定不可燃垃圾处置费和变动垃圾处置费2种情况下,垃圾发电厂如何制订收益分享合同相关条款,促使居民实行垃圾源头分类,并提高可燃垃圾燃烧热值。结果表明:存在唯一的最优分享比例使得发电厂的收益最大,消费者的选择存在最优的可燃垃圾回收数量和最低垃圾燃烧热值水平。     

Breakthrough Technologies for the Biorefining of Organic Solid and Liquid Wastes

Organic solid and liquid wastes contain large amounts of energy, nutrients, and water, and should not be perceived as merely waste. Recycling, composting, and combustion of non-recyclables have been practiced for decades to capture the energy and values from municipal solid wastes. Treatment and disposal have been the primary management strategy for wastewater. As new technologies are emerging, alternative options for the utilization of both solid wastes and wastewater have become available. Considering the complexity of the chemical, physical, and biological properties of these wastes, multiple technologies may be required to maximize the energy and value recovery from the wastes. For this purpose, biorefining tends to be an appropriate approach to completely utilize the energy and value available in wastes. Research has demonstrated that non-recyclable waste materials and bio-solids can be converted into usable heat, electricity, fuel, and chemicals through a variety of processes, and the liquid waste streams have the potential to support crop and algae growth and provide other energy recovery and food production options. In this paper, we propose new biorefining schemes aimed at organic solid and liquid wastes from municipal sources, food and biological processing plants, and animal production facilities. Four new breakthrough technologies—namely, vacuum-assisted thermophilic anaerobic digestion, extended aquaponics, oily wastes to biodiesel via glycerolysis, and microwave-assisted thermochemical conversion—can be incorporated into the biorefining schemes, thereby enabling the complete utilization of those wastes for the production of chemicals, fertilizer, energy (biogas, syngas, biodiesel, and bio-oil), foods, and feeds, and resulting in clean water and a significant reduction in pollutant emissions.     

Methodology for thermal design of novel combined refrigeration/power binary fluid systems

Refrigeration cogeneration systems which generate power alongside with cooling improve energy utilization significantly, because such systems offer a more reasonable arrangement of energy and exergy “flows” within the system, which results in lower fuel consumption as compared to the separate generation of power and cooling or heating. This paper proposes several novel systems of that type, based on ammonia–water working fluid. Importantly, general principles for integration of refrigeration and power systems to produce better energy and exergy efficiencies are summarized, based primarily on the reduction of exergy destruction. The proposed plants analyzed here operate in a fully-integrated combined cycle mode with ammonia–water Rankine cycle(s) and an ammonia refrigeration cycle, interconnected by absorption, separation and heat transfer processes. It was found that the cogeneration systems have good performance, with energy and exergy efficiencies of 28% and 55–60%, respectively, for the base-case studied (at maximum heat input temperature of 450 °C). That efficiency is, by itself, excellent for cogeneration cycles using heat sources at these temperatures, with the exergy efficiency comparable to that of nuclear power plants. When using exhaust heat from topping gas turbine power plants, the total plant energy efficiency can rise to the remarkable value of about 57%. The hardware proposed for use is conventional and commercially available; no hardware additional to that needed in conventional power and absorption cycles is needed.     

国内外生活垃圾焚烧发电技术进展

随着人们对环境方面要求的日益增长,垃圾合理处理在践行绿色发展理念和推动生态文明建设进程中发挥着越来越重要的作用。生活垃圾焚烧发电技术作为固废资源利用的一种方法,如今已经演变成为一种成熟的资源利用技术。分别从垃圾焚烧发电行业的上、中、下游,即从垃圾焚烧的原料性质、燃烧发电技术以及烟气控制方面对国内外生活垃圾焚烧技术进行了比较分析,认为随着生活垃圾量日益增长,生活垃圾焚烧技术仍是一种实现减量化、资源化必不可少的手段,但是需要提升焚烧技术,改进国产焚烧工艺,严格控制焚烧烟气中污染物的排放,建立实时监测点,避免造成二次污染。     

吸收式热泵余热回收先进技术综述

热力发电厂余热资源丰富,且存在锅炉烟气排入大气环境导致的"白羽"现象。为此,国内外学者对烟气余热利用展开了大量研究,其中吸收式热泵作为余热驱动的能级提升装置被广泛应用于区域集中供热和供冷领域。针对目前余热回收领域中应用的回热、多效、多级和压缩-吸收复合的吸收式热泵技术进行综述,并提出一种由双级吸收热泵、升温型压缩吸收耦合热泵和三级烟气换热器组成的烟气余热全热回收系统。该系统基于烟气余热能量梯级利用原理,将烟气由145℃降为40℃以下,同时制取70℃以上的一次热网供暖热水,有效地提升能源利用效率,减少"白羽"现象的产生。     

直接空冷垃圾焚烧电厂的数值模拟计算分析

随着空冷技术在大型火力电厂上的广泛应用和安全运行,越来越多的在北方缺水地区建设的垃圾焚烧电厂,倾向于采用空冷技术,由于垃圾焚烧电厂与火力发电厂在厂房布置形式和空冷岛大小的差异,导致我们并不能简单的套用火力发电厂的空冷技术,在结合大连垃圾焚烧电厂的实地情况,并对该电厂进行空冷技术的数值模拟计算,为后期垃圾焚烧电厂的设计提供理论参考。     

水泥生产中矿渣综合利用的环境负荷分析研究

本研究采用生命周期评价方法定量化利用矿渣生产水泥的环境影响潜力,并与硅酸盐水泥进行对比分析,据此辨识水泥生产中矿渣综合利用的环境热点与改进潜力。研究结果显示,利用矿渣生产水泥的环境负荷相对于硅酸盐水泥降低15％,同时可以避免矿渣处置造成的环境影响。此外,研究证明矿渣在水泥中利用的相关环节,生产过程燃煤燃烧的直接排放与消耗电力的间接排放是造成环境影响的主要来源。因此,降低水泥生产能耗与增加余热回收率是降低环境影响的最有效措施。根据分析,若能达到国际先进化水平15．6％的余热回收率,可进一步使水泥的环境负荷降低6％左右。