氮氧化物(NO_x)脱除技术的研究进展

NOX(氮氧化物)是大气的主要污染物之一,本文主要介绍了氮氧化物的来源、产生的机理及造成的危害,并对生产生活中脱除此类氮氧化物的技术方法进行了总结。     

低温等离子体技术脱除氮氧化物研究进展

针对造成大气污染的主要污染物之一氮氧化物(NO_x),阐述并归纳电子束法、介质阻挡放电法、脉冲电晕法3种低温等离子体脱除氮氧化物技术的工艺特点,介绍几种低温等离子体脱硝技术工作原理及研究进展,并分析各种方法的优缺点,最后对低温等离子体烟气脱硝技术的发展方向进行展望。     

燃煤烟气氮氧化物控制技术研究进展与分析

介绍了当前燃煤烟气氮氧化物控制技术的研究进展和工程应用状况;重点论述和分析了选择性非催化还原法(SNCR)、选择性催化还原法(SCR)、SCR/SNCR联合脱硝法、合成气再燃脱硝法、超细煤粉再燃脱硝法、生物质再燃脱硝法等工艺的脱硝原理、优缺点、脱除率和经济性;提出应以开发适合于我国能源格局的具有自主知识产权的烟气脱硝技术作为未来的研究方向。     

氮氧化物排放控制技术的研究进展

由于氮氧化物特殊的物理化学性质,对燃烧过程中生成的NOx实施控制是一项复杂的技术。本文介绍了NOx的形成机理,阐述了氮氧化物排放控制技术的发展与科研进展,并重点介绍了SCR、等离子体过程烟气脱硝技术。     

烟气干法脱硫技术

简述了烟气中干法脱硫的现状,并对各种不同类下一步地作用机理和技术关键作了介绍和比较,为我国进一步开发研制亲一代烟气中脱硫剂提供参考。     

燃煤电厂烟气氮氧化物(NO_x)的控制技术

就目前国内各环保公司引进的几种国外烟气氮氧化物控制技术:低氮燃烧技术、选择性催化还原技术(SCR)、选择性非催化还原技术(SNCR)分别介绍其控制原理、工艺流程及系统组成,为有关专业技术人员选择烟气脱硝方案提供依据。     

新型干法水泥窑氮氧化物脱除技术

1 水泥窑烟气特性 新型干法水泥生产工艺中．回转窑是NO的主要来源。煅烧水泥熟料时生成NO的途径主要有四种。即第一种热力NO．它是燃料在水泥窑头1400℃以上燃烧时会产生大量NO;第二种瞬发NO,它是有碳氢根存在时,于火焰前端瞬发形成的NO．一般这种瞬发NO生成量的比例很小：第三种燃料NO。它是由燃料中所含的化学接合氮所产生的。例如煤中约含有0．5％～2％的氮（按质量计）。因为燃料中氮原子的接合能较小,所以在水泥窑系统相对较低温的分解炉内产生的燃料NO较多：     

烟气二氧化硫脱除技术改进

结合焦作铁路电缆厂烟气治理现状,对原有烟气治理设施提出了改造方案。通过改造,能够实现对烟气中二氧化硫的有效脱除。     

燃气-蒸汽联合循环机组烟气氮氧化物的排放规律

针对燃气-蒸汽联合循环机组运行过程中排放黄烟的现象,开展了烟气污染物（NO和NO₂）浓度的现场测试,研究了联合机组运行工况和生产负荷对其排放特性及变化规律的影响。结果表明：烟气中NO浓度和氮氧化物（NO _x ）浓度随机组生产负荷的增大而增大,NO₂浓度以及NO₂与NO _x 的浓度比值（NO _x 构成）则随生产负荷增加而逐渐降低。联合机组在单循环和低负荷工况运行时,黄色烟羽成因是烟气中NO₂含量高造成的,与烟气中NO _x 浓度和NO浓度没有明确的对应关系;提高联合机组生产负荷,会减少NO₂在氮氧化物中所占的比例,有助于缓解烟气黄色烟羽的生成。此外,初步分析了燃气轮机燃烧器的运行模式,认为值班燃烧区形成的高温富氧条件是造成排放高浓度NO₂烟气的重要原因。     

Simultaneous Catalytic Removal of Nitrogen Oxides and Soot from Diesel Exhaust Gas over Potassium Modified Iron Oxide

Iron oxide modified by potassium, i.e. Fe_1.9K_0.1O₃, exhibits high catalytic performance for the simultaneous conversion of soot and NO_x into CO₂ and N₂. The present study shows that long‐time treatment of the catalyst leads to a drastic decrease in the activity, whereas even the aged catalyst maintains considerable activity. On the other hand, long‐time treatment causes selective N₂ formation, i.e. no more formation of the byproduct N₂O. This alteration of catalytic performance is likely due to agglomeration of the promoter potassium being present at the surface of catalyst. Detailed experiments were carried out with a more realistic diesel model exhaust gas to confirm that Fe_1.9K_0.1O₃ is a suitable catalyst for the simultaneous removal of soot and NO_x between 350 and 480 °C. It was assumed that (CO) intermediates, formed by the catalytic reaction of NO_x and oxygen with the soot surface, are the reactive species in NO_x‐soot conversion.     

轻油裂解法生产氰化钠尾气净化新工艺

介绍了一种氰化钠尾气的净化工艺,将轻油裂解法生产液体氰化钠中富含氢气的尾气净化处理．在脱氰塔内用氢氧化钠溶液吸收尾气中的氰化氢,脱氨塔内用水吸收尾气中的氨气,通过脱氰、脱氰工艺将净化后的含氢气体输送到合成氨车间作为生产液氨的原料。     

基于Fluent的微通道天然气废气重整的数值模拟

利用Fluent软件对微通道反应器中天然气废气重整进行数值模拟。利用甲烷来代替天然气进行模拟。多通道反应器由具有平行通道的堇青石块组成,每个平行通道用Rh/Al_2O_3催化剂洗涂。由于堇青石的低热导率,通道之间的热传递被忽略。研究了进料温度,燃料组成和天然气中存在的丙烷对温度和产物分布的影响。通过模拟结果可得出:开始温度沿着通道良好地分布,并且没有形成明显的热点;增加进料温度有利于甲烷转化和氢气生产,但会导致温度分布不均;提高进料中蒸汽的量有助于增加氢气形成,但轻微地减弱了甲烷转化;提高入口处的O_2/C比值可导致甲烷转化率和温度成比例地增加。     

焦炉废气作煤调湿系统载气的实施分析

阐述了在煤调湿技术中采用空气作为载气的缺陷,提出以焦炉废气代替空气作为系统载气的改进方案.该方案不仅能保证系统氧含量不超标,确保系统运行安全,而且能节约蒸汽和氮气用量.     

Surface Properties and Catalytic Performance of La0.8K0.2CuxMn1–xO3 for Simultaneous Removal of NOx and Soot

The influence of copper substitution in La_0.8K_0.2Cu_xMn_1–xO₃ on its catalytic performance for simultaneous removal of NO_x and soot under oxygen rich conditions was investigated. A series of catalysts was prepared and then characterized by XRD, SEM, BET, and XPS. The temperature programmed reaction (TPR) method was used to evaluate the catalytic performance of the catalysts. XRD results show that the partial substitution of Cu for Mn promotes the formation of perfect perovskites. SEM and BET results demonstrate that appropriate copper substitution enhances the porosity and increases the specific surface area, leading to conditions which are favorable for heterogeneous catalysis. XPS results indicate that a fraction of the Mn³⁺ is converted to Mn⁴⁺ on the addition of low levels of Cu. By correlation of the physicochemical properties and the catalytic performance, a large specific surface area, high porosity, high content of Mn³⁺ and synergistic effects of Mn³⁺ and Cu²⁺ are seen to favor the simultaneous catalytic removal of NO_x and soot.     

Kinetic and CFD Modeling of Exhaust Gas Reforming of Natural Gas in a Catalytic Fixed-Bed Reactor for Spark Ignition Engines

Fuel reforming is an attractive method for performance enhancement of internal combustion engines fueled by natural gas, since the syngas can be generated inline from the reforming process. In this study, 1D and 2D steady-state modeling of exhaust gas reforming of natural gas in a catalytic fixed-bed reactor were conducted under different conditions. With increasing engine speed, methane conversion and hydrogen production increased. Similarly, increasing the fraction of recirculated exhaust gas resulted in higher consumption of methane and generation of H₂ and CO. Steam addition enhanced methane conversion. However, when the amount of steam exceeded that of methane, less hydrogen was produced. Increasing the wall temperature increased the methane conversion and reduced the H₂/CO ratio.     

环境中污染源废气检测方法及影响因素分析

对污染源废气监测原理进行了简单分析,阐述了当前我国常用的环境中污染源废气检测方法,并对废气检测影响因素及质量控制进行了深入探究。     

催化剂生产中NO_x废气治理技术影响因素分析

介绍了FYHG-DN技术治理NOx废气的原理和技术特点,分析了催化剂生产过程中含NOx废气排放特点和影响FYHG-DN氮氧化物治理装置处理效果的因素,并对各因素提出有针对性的措施,以保证更好的处理效果,满足长周期稳定运转的生产需求。     

Catalytic Activity of Ceramic Honeycombs in the Exhaust Gas Oxidation of a Waste Treatment Plant

The activity of ceramic honeycombs with varying material composition and degree of utilization is compared on a suitable model gas in a test plant. The tested honeycombs are standard products that have not been surface‐treated in any way. A propane‐air mixture was fed to the test plant and then oxidized in a high‐temperature furnace. The analysis of the conversion rate over the reaction temperature showed remarkable differences in activity. The honeycomb with the most promising results was further investigated with the exhaust gas from the drying process of a waste treatment plant. Finally, the activity of this honeycomb was assessed in a large‐scale trial in an existing running regenerative thermal oxidizer.