水泥窑烟气脱硝技术的发展与创新(上)

<正>1概述"十二五"期间,我国氮氧化物排放总量要求达到减排10%的目标。水泥行业氮氧化物的排放量占全国工业排放总量的15%左右,居火力发电、汽车尾气之后,是氮氧化物排放第三大户,属污染控制重点行业。工信部"582"号文件关于水泥工业节能减排的指导意见要求:到"十二五"末,氮氧化物在2009年的基础上降低25%;新建或改扩建水泥(熟料)生产线项目必须配置脱硝装置,且脱硝效率不低于60%。     

《氮氧化物减排》一书已出版

<正>本刊讯《氮氧化物减排》一书已出版,该书由中国建材工业出版社出版发行。水泥工业是氮氧化物的重要排放源。当前,水泥企业减排任务艰巨。进入"十二五"后,环境形势的变化对水泥工业大气污染防治,特别是氮氧化物总量减排提出了更高的要求。水泥工业烟气脱硝技术在我国起步时间短,烟气脱硝技术方案尚没有统一的标准,工程质量和实际脱硝效果千差万别。为使读者对水泥工业烟气脱硝技术有一个更深入的了解,本书对此技术做了全面详细的介绍,广泛收集了国内外水泥行业烟     

水泥窑几种典型脱硝技术的比较

我国是以燃煤为主的发展中国家,燃煤造成的大气污染日趋严重,而氮氧化物(NOx)是其主要成分之一,包括NO、NO2、N2O、N2O3、N2O5等多种氮的氧化物,燃煤窑炉排放的NOx中绝大部分是NO,NOx除对人体有害外还导致光化学烟雾和酸雨的形成。目前我国水泥行业氮氧化物的排放占总排放量的10%左右,是我国氮氧化物排放的第三大源,因此治理水泥行业氮氧化物的排放刻不容缓。水泥窑脱硝的技术主要有:低氮燃烧技术(包括低氮喷煤管、空气分级燃烧和燃料分级燃烧)、SNCR和SCR。本文对这几种脱硝技术做了初步的比较,供水泥行业选择。     

尘硝一箱化SCR脱硝技术在窑尾烟气降氮节能中的设计运用

水泥行业脱除氮氧化物普遍采用选择性非催化还原（SNCR）脱硝技术,但脱硝效率不高,氨水用量较大,易造成氨逃逸等二次污染问题。随着大气污染防治工作从单一污染物治理转向多污染物协同治理,尘硝一箱化SCR脱硝工艺,将为我国水泥行业NOx深度减排提供技术支撑。     

水泥行业脱硝现状和工艺技术的探讨

目前,我国正在大力推行水泥行业脱硝,控制水泥行业的氮氧化物排放.文章从水泥行业氮氧化物的污染现状、产生机理、国家排放标准以及脱除工艺技术、方法等方面进行探讨,并对“十二五”我国水泥行业氮氧化物的减排提出了一些建议.     

高固气比悬浮预热分解系统脱硝优势理论分析

随着水泥行业氮氧化物的污染越来越严重,研究并发展实用于水泥行业的脱硝技术也越来越迫切.本文首先介绍了水泥工业中NOx排放类型及其主要的脱硝技术,这些技术目前已经投入使用,但都存在一些问题,仍需进一步研究与实践;最后介绍了高固气比悬浮预热分解系统脱销理论并通过对其技术鉴定,NOx排放可降低50％以上.     

SCR烟气脱硝技术的研究与应用

随着国家对大气污染物排放标准的严格要求,水泥行业的氮氧化物减排形势严峻.本文针对目前水泥窑氮氧化物排放情况,分析了氮氧化物减排现状.同时根据燃煤电厂和玻璃行业的SCR烟气脱硝技术的发展应用现状,阐述了水泥窑SCR烟气脱硝技术的应用前景,并介绍了低温SCR催化剂的研究现状.     

水泥生产系统氮氧化物的产生过程和控制措施

近年来,随着我国水泥产量的不断攀升与水泥产品结构的调整,水泥工业氮氧化物(NOx)排放量也呈现了快速增长的趋势,有关数据显示,2000年我国水泥工业NOx排放量为77万t,2005年为136万t,2010年达到200万t,占我国NOx排放总量的10%。水泥工业NOx的排放控制也越来越重要,相关部门相继出台了一系列政策与排放控制标准:GB50259-2008水泥厂设计规范规定,水泥厂焚烧废弃物NOx排放量     

水泥窑脱硝工艺技术的探讨

2009年,中国NOx排放量已高达1 692.7万t,2010年达2 273.6万t,而2011年交2011年增加7.5％,若不采取进一步控制措施,到2020年,NOx排放总量将达到3 000万t,超过美国成为NOx排放量居世界第一的国家. 目前,我国水泥行业氮氧化物的排放占总排放量的10％左右,是我国氮氧化物排放的第三大源.随着水泥行业落后产能淘汰工作的推进,新型干法窑的使用比例将大幅增加,在提高能源使用效率的同时,由于燃烧温度高等原因,氮氧化物排放量将显著增加.     

水泥工业也可变身绿色产业——新书《氮氧化物减排》提供了最直观有效的减排指导

<正>水泥工业是氮氧化物的重要排放源。当前,水泥企业减排任务艰巨。进入"十二五"后,环境形势的变化对水泥工业大气污染防治,特别是氮氧化物总量减排提出了更高的要求。从世界范围来看,已实施的水泥厂脱硝工程,几乎全部采用SNCR脱硝技术,是目前水泥行业脱硝的主流技术。SNCR脱硝技术占地面积小、对工业窑炉改造的工作量少、施工安装周期短、节省投资。于是在国家政策、资金的引     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Novel polyurethane coating technology through glycidyl carbamate chemistry

Glycidyl carbamate chemistry combines the excellent properties of polyurethanes with the crosslinking chemistry of epoxy resins. Glycidyl carbamate functional oligomers were synthesized by the reaction of polyfunctional isocyanate oligomers and glycidol. The oligomers were formulated into coatings with several amine functional crosslinkers at varying stoichiometric ratios and cured at different temperatures. Properties such as solvent resistance, hardness, and impact resistance were dependent on the composition and cure conditions. Most coatings had an excellent combination of properties. Studies were carried out to determine the kinetics of the curing reaction of the glycidyl carbamate functional oligomers with multifunctional and model amines. Detailed kinetic analysis of the curing reactions was also undertaken. The results indicated that the glycidyl carbamate functional group is more reactive than a glycidyl ether group. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, on October 27–29, 2004, in Chicago, IL.     

Highly moisture-proof polysilsesquioxane coating prepared via facile sol-gel process

A highly moisture-proof polysilsesquioxane coating was obtained from a new bis-silylated precursor, which was synthesized from 3-aminopropyltriethoxysilane (APTES) and m-xylylene diisocyanate (m-XDI) in tetrahydrofuran (THF) and verified by ¹H MAS NMR. For direct comparison purposes, an SiO₂ coating was also prepared by the Stöber method using tetraethoxysilane (TEOS) as the reactant. Interestingly, the coating obtained from the polysilsesquioxane sol exhibited a much higher moisture resistance capability than its counterpart, which was attributed to its more compact feature between nanoparticles as characterized by N₂ absorption experiment and transmission electron microscopy (TEM). Furthermore, its high transparency of about 92% showed potential for application in the protection of optical crystals.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.