城市生活垃圾处理的清洁生产发展机制

结合清洁发展机制介绍了我国垃圾处理的相关情况,分析填埋和焚烧垃圾处理的碳排放及能源利用情况,并分别给出典型案例。简要评估垃圾填埋、焚烧发电CDM项目的前景。     

西藏生活垃圾掺烧市政污泥的焚烧特性研究

西藏自然环境条件特殊,生态环境脆弱。随城市化和旅游业快速发展,生活垃圾/污泥产量急增。目前,生活垃圾/污泥仍以填埋为主,焚烧处于试运行,总体上缺乏先进的处置技术。本研究分析了西藏垃圾/污泥的特点;利用层燃焚烧炉分析了西藏和天津垃圾/污泥在焚烧过程中的差异,探讨了西藏垃圾和污泥在不同混合比下的焚烧特性。初步确定了西藏污泥与垃圾混合焚烧的最佳掺混比为4∶1,CO排放降低达23.06%,HCl降低达45.51%,颗粒物浓度降低约30.73%。考虑到西藏生态环境的不可逆转性及其作为国家生态安全屏障的战略性,本研究为其固废混合焚烧处理过程的污染物控制提供了指导,为混合焚烧处理的工程化应用提供参考。     

硫化床炉焚烧垃圾发电供热工程落成

从哈尔滨市计委获悉,作为全国示范项目,国内第一座利用硫化床炉焚烧垃圾发电供热工程,近日被国家     

废塑料回收利用或终结填埋焚烧时代

<正>塑料自然降解需要百年以上,而其析出的添加剂会污染土壤和地下水等。目前,废塑料大多采用填埋、焚烧等方式,不仅对生态无益,反而带来了二次污染。只有完美的利用废塑料,方能终结填埋焚烧时代。塑料包装废弃物的处理方法基本上可分为填埋、焚烧及回收再生利用。填埋是把垃圾作为废物处理,对垃圾资源的利用率低,不符合国家可持续发展战略。焚烧法可将不能再次利用的混杂塑料在焚烧炉中焚化,由其产生的大量热量可再次充分利用。但焚烧的过程中会产生大量的有害气体,对环境及人体造成危害。     

水泥窑和焚烧炉联合处理生活垃圾技术和效果

水泥窑和焚烧炉联合处理城市生活垃圾技术是把垃圾焚烧炉建在水泥窑旁边，利用冷却熟料的热风作为垃圾燃烧空气，垃圾在无外加燃料的情况下稳定燃烧，焚烧产生的热能替代水泥烧成的燃料，灰渣作为水泥生产的原料，做到垃圾的资源化、无害化、无残留物处理，具有比其它焚烧方式更好的环境友好性。经济分析说明该技术投资省、处理成本低，投入产出比高。该技术的应用，将产生政府和企业双赢，环境和效益双赢的效果。     

列入国家先进污染防治技术目录的水泥行业项目

2021年1月26日,生态环境部发布了2020年《国家先进污染防治技术目录(固体废物和土壤污染防治领域)》的公告,其中,涉及热盘炉水泥窑协同焚烧处置生活垃圾技术。技术名称:热盘炉水泥窑协同焚烧处置生活垃圾技术工艺路线:生活垃圾经预处理后输送到热盘炉内可缓慢旋转的炉盘上进行焚烧,可通过调节炉盘转速调节生活垃圾焚烧停留时间。焚烧底渣进入水泥窑参与熟料反应生产水泥熟料,烟气经治理后达标排放。     

焦炉处理废塑料的节能及环保效果

对全球环境而言，21世纪迫切要求有效利用资源，构建循环型社会。近年来，家庭排出的废塑料数量逐年增加，因不能再生而作为垃圾进行焚烧或填埋处理，现已经成为社会问题。为防止全球变暖，日本钢铁联盟在其自主行动计划中提出，到2010年整个钢铁行业要利用100万t／a的废塑料，所用能源将比1990年减少1．5％。     

餐厨垃圾与生活垃圾焚烧协同处置的工程应用

某市建设的循环经济环保科技示范项目集生活垃圾焚烧、污泥干化、餐厨垃圾和粪便联合厌氧消化为一体,总体工艺设计从循环经济园区角度考虑,共用公辅设施、互为能源原料、工艺系统联通,实现多种垃圾的协同处置。其中餐厨和粪便处理采用"预处理+联合厌氧消化"工艺,利用焚烧系统蒸汽热源满足工艺需求,产生沼气作为辅助燃料回馈焚烧炉,厌氧产渣作为固体燃料与生活垃圾掺混处理,污水产物进入生活垃圾渗滤液处理系统。相较于单一处理模式的独立设厂,建设造价大为减少,运营成本明显降低,人力资源占用少,园区内处理避免不同处理厂间物料渣滓运输对环境造成危害,实现经济效益与环境保护共赢,契合国家垃圾分类及完善垃圾处理终端设施的政策要求和市场走向。     

水泥窑协同处置生活垃圾对水泥生产的影响

正在我国,垃圾的回收处理主要以焚烧发电为主,与焚烧发电相比,水泥窑处理生活垃圾更加环保、安全,同时也能为社会带来更大的经济效益和社会价值,已经逐步受到城乡各级政府和大中型企业的重视和关注。用水泥窑协同处置生活垃圾不会引发二次污染,而用焚烧垃圾来发电不仅会生成二噁英等有害气体和毒性飞灰、残渣,也会带来后续的处理问题。同时,用水泥窑协同处置生活垃圾,也能替代一部分原、燃材料,降低了水泥企业的生产成本。然而,从水泥生产管     

对垃圾发电与水泥窑协同焚烧两种垃圾处置方式的再认识

<正>在垃圾焚烧领域,主要有两种方式:一是新建垃圾发电厂,将消纳焚烧垃圾所产生的热能转化为电能回收利用;二是利用已有的水泥厂,将经过适当预处理的垃圾喂入水泥窑系统中燃烧,在水泥窑正常生产熟料的同时,把这些垃圾一并消纳烧尽。垃圾燃烧时所产生的热能可以直接用于熟料的煅烧,节省或替代相应数量的熟料煅烧用煤,谓之水泥窑协同处置。1国外垃圾处置方式     

煤与垃圾衍生燃料的混烧技术

简要分析了我国的城市垃圾处理现状 ,介绍了垃圾衍生燃料的种类、制作方法及国内外研究进展。鉴于我国城市垃圾热值低、灰分高的特点 ,建议将垃圾制成垃圾衍生燃料后掺混到现运行的燃煤锅炉中 ,以实现资源化利用。统计了该方法在国外的运行情况 ,并对我国采取该方法的可行性进行了分析。论证结果表明 ,该方法投资省、污染低 ,对我国的环境卫生建设和经济建设具有重要意义     

煤与垃圾衍生燃料混烧技术展望

介绍了垃圾衍生燃料的种类、制作方法以及目前研究状况。针对中国城市垃圾的特点，提出将垃圾制成垃圾衍生燃料后掺混到现运行的燃煤锅炉中的建议，以实现资源化利用。统计和分析了该方法在国内外的运行情况，并对该方法的可行性、经济性进行了分析论证。结果表明，该方法所需建设投资少、运行成本低，适合中国目前垃圾处理的国情。     

SEM–EDS characterization of inorganic material in refuse-derived fuels

The utilisation of refuse-derived fuel (RDF) in energy production is restricted by their inorganic impurities, such as heavy metals and chlorine. In this contribution, three different types of RDF were studied by SEM–EDS. These materials originated from three locations: construction sites, households, and supermarkets. Several fuel samples of every type of RDF were used in this study. The compositional distributions of the inorganic particles were determined directly from each fuel and the results are presented as quasiternary diagrams. The presentation method makes it possible to identify inorganic particles such as sand, alkali metal chlorides, calcium chloride, gypsum, lime, titanium pigment, iron as an element or oxide, and metallic aluminium from fuel. The results can be used to discuss the origin of different inorganic components in these materials and serve as a base for discussion of the suitability to use each waste material as fuel. It also facilitates the design of appropriate purification steps that are needed.     

Determination of the biogenic and fossil organic matter content of refuse-derived fuels based on elementary analyses

A method to determine the mass, energy and carbon content of biogenic and fossil matter in refuse-derived fuel (RDF) is described. The method combines standard chemical information about biogenic and fossil material with data from a chemical analysis of the RDF. The data are used to solve a set of equations that deliver the mathematically and statistically derived final result. For the chemical analysis representative samples of the RDF were assessed in a CHNSO elemental analyser. The proposed method was validated by characterizing defined reference mixtures of plastics and biomass (e.g., polyethylene and cardboard). The correlation coefficient (r²) between the measured and reference values was greater than 0.99. If representative sampling of RDF is assumed, the new method represents a reliable, quick and complementary method for characterizing RDF.     

A particle scale model for municipal solid waste and refuse-derived fuels pyrolysis

The solid phase decomposition during pyrolysis of municipal solid waste (MSW) and refuse-derived fuels (RDF) is modelled on particle scale accounting for heat and mass transfer. Waste pyrolysis is expressed as a linear combination of pyrolysis of its components. The novel characterization method used expresses waste composition in terms of three reference species. The selected species are a mixture of cellulose and hemicellulose, a mixture of polystyrene and polyethylene terephthalate, and a mixture of polyethylene and polypropylene. The pyrolysis kinetics models for these components are taken from the literature. The fractions of the components in the mixtures are optimized to fit the model to non-isothermal mass loss curves from selected experimental reports. The particle scale model has been evaluated against experimental transient temperature profiles at the centre of a large waste pellet during pyrolysis. The model is able to predict the main trend, but shows a more fluctuating temperature curve.     

Pyrolysis of municipal solid waste

A state-of-the-art review describing the characteristics of municipal solid waste (MSW) and assessing the chemistry and technology of pyrolysis of municipal solid waste is presented. The economics of the pyrolysis process are outlined. Combustibles constitute on average about 60% of the weight of MSW and result in an average heating value (“as received” basis) of about 3,000 to 6,000 Btu/Ib. This makes MSW attractive for thermal treatment. Municipal solid waste can be converted to gas, liquid and solid products by pyrolysis. Due to the complexity in composition of MSW the exact mechanism of pyrolysis is not known. Both homogeneous and heterogeneous reactions occur at the same time and both heat and mass transfer take place during the process. The relative yields of different products depends on the temperature of pyrolysis and the rate of heating. High pyrolysis temperatures and high heating rates favour the production of gases indicating high energies of activation for gasification reactions. At low temperatures, below 800°C, the pyrolysis process is reaction-rate controlled, while at high temperatures, above 1,200°C, the process is diffusion-rate controlled. Conditions of good heat and mass transfer are required for gasification of MSW. The residual char after pyrolysis can be gasified by further treatment with steam, hydrogen or carbon monoxide and water. The heat available from the products of pyrolysis is sufficient to sustain the process and yield some excess energy. Three types of reactor design have been generally used in the investigation of pyrolysis of MSW; fixed bed reactor, fluidized bed reactor and rotary kiln reactor. The advantages and weak points of each of these are briefly discussed. The costs of disposal of MSW by pyrolysis appear to be competitive with incineration.     

Effect of vibration condition and inter-particle frictions on the packing of uniform spheres

We present a numerical study of the packing of uniform spheres under three-dimensional vibration using the discrete element method (DEM), focusing on the effects of vibration condition (amplitude and frequency) and inter-particle frictions (sliding and rolling frictions). The results are analysed in terms of packing density, coordination number (CN), radial distribution function (RDF) and pore structure. It is shown that increasing either the vibration amplitude or frequency causes packing density to increase initially to a maximum and then decrease. Both vibration frequency and amplitude should be considered to characterize the effect of vibration process on packing structure. The sliding and rolling frictions between particles can decrease packing density since they dissipate energy, although the effect of rolling friction is less significant. In line with the change of packing density, microstructural properties such as CN, RDF and pore distribution also change: a looser packing often corresponds to smaller CN, less peaked RDF and larger but more widely distributed pores.     

有机固体废弃物热化学制氢研究进展

氢气是理想的清洁能源,也是重要的化工原料。但是,目前的制氢技术多以化石燃料为原料,制氢过程具有高能耗和高污染的弊端,这使氢能的清洁属性大打折扣。随着社会经济的发展和城市化进程的加快,城市固体废弃物的产量逐年递增,这其中的大部分有机物都有成为制氢原料的潜力。以有机固体废弃物（简称“有机固废”）为原料的制氢工艺对于氢能的清洁化发展和固废的资源化利用具有双重意义。本文以有机固废热化学转化制氢过程为对象,对该过程的原料预处理、技术路线、催化剂和吸附剂、技术经济分析、生命周期评价和生态风险评估等方面的研究进展进行综述,重点聚焦大型中试装置和工业化示范项目。通过分析各类技术路线的优劣性,总结得出新型热化学转化制氢技术受成本和装备的限制,大规模利用进展缓慢。在传统热化学转化制氢领域中,有机固废气化制氢最具大规模应用潜力。根据有机固废制氢的发展现状,还对该领域催化剂和吸附剂未来的研究方向以及技术经济分析和生命周期评价的热点问题进行讨论。最后对有机固废制氢的前景作出展望。     

A comparative study on co-combustion performance of municipal solid waste and Indonesian coal with high ash Indian coal: A thermogravimetric analysis

In recent years there has been an increasing utilization of coal blends in the Indian power industry, with Indonesian coal, due to high ash content and shortages in domestic coal production. On the other hand, rapid economic growth is aggravating the municipal solid waste (MSW) related environmental problems. In this study, an attempt has been made to compare the co-combustion characteristics of hydrothermally treated MSW and Indonesian coal with high ash Indian coal, so as to replace the Indonesian coal with MSW. The effect of blending Indonesian coal and hydrothermally treated MSW with Indian coal on ignition behavior was studied. MSW blends of 10%, 20%, 30% and 50% (in wt.%), and an Indonesian blend of 10% with Indian coal were tested in a thermogravimetric analyzer (TGA) in the temperature from ambient to 700 °C with a temperature increase of 10 °C/min. From the results, at 10% of blend, ignition and carbon burnout were similar for Indonesian and MSW blend, analogous to coal combustion and even better than the Indonesian coal blend, which indicated the feasibility for replacing Indonesian coal with hydrothermally treated MSW. Further, the results show a scope to increase the MSW blend in Indian coal up to 20%, as the constituents behave as a single fuel.     

垃圾预处理条件对渗滤液组分及其微生物燃料电池处理效果的影响

在实际生产生活中,城市垃圾焚烧或热解处置前一般需经过7~10 d的堆放预处理,预处理可去除垃圾中部分水分、提高垃圾热值,对于垃圾处理质量、热能回收、污染物排放等有着重要的影响。因此,本实验详细跟踪了城市垃圾预处理条件如堆放温度、堆放时间等对城市垃圾含水率、渗滤液产生量和渗滤液组分的影响,并进一步考察了其对渗滤液微生物燃料电池处理效果的影响。垃圾堆放温度实验结果显示,当垃圾堆放于40℃时效果最佳,此时垃圾减重率适中,所得的渗滤液中B/C比约为0.31、氨氮浓度约为1560 mg·L^-1,适宜生化处理。此条件下所得的渗滤液经MFC处理时电池可获得0.29 V的输出电压,且经7 d处理后渗滤液中COD、氨氮去除率可分别达66.2%和87.2%。随后,在最佳堆放温度下进一步考察堆放时间的影响。结果显示,在最佳堆放温度40℃下,垃圾堆放6 d后所得的渗滤液组分最易于生化处理,其B/C比约为0.32、氨氮浓度约为1520 mg·L^-1,经MFC处理时电池可获得0.29 V的输出电压,且经7 d处理后渗滤液中COD、氨氮的去除率分别为62.7%、87.6%。综上所述,40℃下堆放6 d是城市垃圾焚烧或热解处置预处理的最佳条件,此条件下,垃圾减重率和渗滤液产生量适中,且所得渗滤液可生化性较强,适合用于MFC产电处理。