Supported heteropolyacids for NO x storage and reduction

Topics in Catalysis - TiO2 and SnO2 were studied as possible supports for HPW in order to produce a new type of sorbent for NO x trap applications. SnO2 was synthesised by various inorganic methods...     

煤燃烧过程中NOx的生成和还原

燃煤过程中ＮＯｘ 的排放是一个复杂的过程, 既包括ＮＯｘ 的生成过程又包括生成的ＮＯｘ 进行均相和多相还原反应． 简述了煤燃烧过程中ＮＯｘ 生成和还原的机理． 认为燃料氮是ＮＯｘ的主要来源,ＮＯｘ 的排放与煤阶、煤中氮含量以及温度等因素有关;ＮＯｘ 与半焦的多相反应是ＮＯｘ还原的主要原因, 其中包括ＮＯｘ 在半焦表面的化学吸附、表面络合物的生成以及产物的生成和脱附等过程     

Mycobacterial sulfolipids: Spontaneous desulfation

A glycolipid sulfate elaborated in abundance by surface-grown cultures ofMycobacterium tuberculosis has been characterized in earlier studies as a complex 2,3,6,6′-tetraacyl α, α′ trehalose 2′-sulfate. The purified ammonium salt undergoes rapid quantitative desulfation on mere dissolution in reagent grade anhydrous ether. The same reaction is observed in sulfolipids recovered from a number of human strains and one bovine strain. Experimental observations on the normal and acid-catalyzed rates of the reaction and on the influence of other solvents and other cationic forms support a proposed mechanism, which is detailed. Structural criteria which may influence the proclivity for spontaneous desulfation are discussed.     

旋流浓淡燃烧器中煤粉浓缩器对煤燃烧NOx生成的影响

应用数值模拟方法研究了旋流燃烧器中煤粉浓缩器对煤燃烧NO_x生成的影响，给出了热NO_x和燃料NO_x生成的详细信息.预报结果表明：采用作者研制的弱旋煤粉浓缩器后，可以大大地降低燃烧器出口区域燃料NO_x的生成，同时可以保持煤粉颗粒较高的燃尽率.模拟结果也表明，燃烧器出口区域的NO_x生成主要是由燃料NO_x的生成机理来控制，热NO_x在总NO_x的生成量中所占比例不大.因此，该旋流浓淡燃烧器具有高效低污染性能.     

Comparative NO x reduction behavior of Pt,Pd, and Rh supported catalysts in simulated exhaust gases as a function of oxygen concentration

Topics in Catalysis - NO x reduction activity on Pt and Pd catalysts had a maximum for S value as stoichiometry number at a fixed temperature, and the S value at the maximum NO x conversion...     

NO x and VOC Control and Its Effects on the Formation of Aerosols

This research analyzes the qualitative and quantitative behavior of aerosol dynamics resulting from the control of nitrogen oxide (NO x ) and volatile organic compound (VOC) emissions by calculating detailed pollutant isopleths. Several emission scenarios are evaluated using various norms to study the nonlinear impact of control strategies. The modeling episode studied is the Southern California Air Quality Study on August 27, 28, and 29, 1987. The modeling domain is the South Coast Air Basin of California. Research suggests that the reduction of NO x and VOC emissions traditionally implemented to control ozone also controls particulate matter, but to a limited extent. Furthermore, the effects of reducing NH 3 are more effective in PM control than reducing both NO x and VOC. Simulations indicate that the combined control of NH 3 , NO x , and VOC emissions is most effective to reduce particulate matter and ozone in the South Coast Air Basin of California.     

固体吸附/再生法同时脱硫脱硝技术的研究进展

在静态污染源的排放物中，SOx和NOx是导致光化学烟雾和酸雨的主要污染物，又较难净化处理，因此针对它们的控制技术受到了广泛的重视，本文综述了用固体吸附法同时脱除硫氧化物和氮氧化物的研究现状和进展。包括炭质材料吸附法，氧化铜吸附法，NOXSO，以及当今国外广泛研究的储存还原技术。     

Evaluation of a NO x reduction system on an engine rig under stationary operation

Topics in Catalysis - The NO x storage and reduction approach was applied on a full-scale engine rig under stationary operation. NO x reduction experiments were performed and a catalyst model...     

选择性催化还原法脱硝研究进展

催化脱硝是目前研究较多的脱除氧化物的方法 ,分为催化分解法和催化还原法 .后者又分为选择性催化还原法 ( SCR)和非选择性催化还原法 ( NSCR) .概述了 NH3 作还原剂的SCR法 .介绍了选择性催化还原降低氮氧化物排放技术 ( SCR)的机理、SCR技术催化剂使用情况、SCR反应的吸附机理、反应化学关系式以及化学动力学研究 .同时展望了这一技术领域的重点研究方向     

Optimization of a Composite Working Electrode for a New Family of Electrochemical Cell for NO Decomposition

The electrochemical properties of a composite (NiO) _x −(yttria-stabilized zirconia (YSZ))_{1– x} working electrode for a new type of electrochemical cell for NO decomposition in the presence of excess oxygen are investigated. It is shown that the dependence of the NO conversion on the value of the current passed through the electrochemical cell with a nanoporous (NiO) _x −(YSZ)_{1– x} working electrode is linear and that the value of current efficiency depends on the NO and O₂ gas concentrations only (η= [NO] /([NO] + 2[O₂]). The optimum NiO addition (35% by volume) to the YSZ resulted in a decrease of the cell operating voltage and, as a result, in a decrease in the electrical power required for NO decomposition. The observed high performance of the composite working electrode at this composition is consistent with the effective medium percolation theory, which predicts the ambipolar transport behavior of the composite mixed ionic−electronic (YSZ–NiO) conductors as a function of the volume fraction of each of the randomly distributed constituent phases.     

Formation of Polyketones in Irradiated Toluene/Propylene/NO x /Air Mixtures

A laboratory study was carried out to investigate the formation of polyketones in secondary organic aerosol from photooxidation of the aromatic hydrocarbon toluene, a major constituent of automobile exhaust. The laboratory experiments consisted of irradiating toluene/propylene/NO x /air mixtures in a smog chamber operated in the dynamic mode and collecting submicron secondary organic aerosol samples on Zefluor filters and on stainless steel disks in a low pressure cascade impactor. Carbonyl oxidation products in methanol extracts of the filters were derivatized using O-(2,3,4,5,6,-pentafluorobenzyl)-hydroxylamine, and the oxime derivatives were detected with a positive chemical ionization gas chromatography ion trap mass spectroscopy (GC-ITMS) system. Infrared spectra of the cascade impactor samples were used to determine the chemical functional group concentrations of the aerosol. The results of the GC-ITMS and infrared spectral analyses were consistent with the formation of multifunctional oxygenates, including hydroxy diones as well as triones, tetraones, and pentaones.     

钙镁铝型三元类水滑石的合成及其在PVC中的应用

在Ca（NO3）2-Mg（NO3）2-Al（NO3）3-NaOH体系中,采用共沉淀法制备钙镁铝三元类水滑石。考察了反应沉淀过程的原料配比对合成水滑石结构的影响。并用XRD、IR和粒度分析等手段对合成样品进行分析和表征。结果表明：在制备条件x（Mg^2＋）：x（Ca^2＋）为1-3,x（M^2＋）氏（M^3＋）为2-4范围内,反应沉淀pH值为10左右。合成的CaMgAl水滑石的晶相结构最完整。合成的产物可以大大改善PVC的热稳定性。     

锅炉排污水用于烟气脱硫脱氮

介绍了利用锅炉碱性排污水或化学碱性水对锅炉尾部烟道进行喷淋,以脱除烟气中的大部分SO2和NO2的技术及实践成果,研究了喷淋方式,喷雾水量,喷水碱度对脱除效果的影响。     

燃气轮机降低氮氧化物排放的干式方法

阐述了燃气轮机降低氮氧化物排放的方法。重点介绍了ＧＥ公司开发的降低氮氧化物排放的干式方法，此法可大大降低氮氧化物的排放。     

新型受控脉动燃烧技术在陶瓷烧成试验窑上的应用

在工业炉上试用该技术具有降低NOx排放量、节能、温度均匀等优点。本试验在陶瓷烧成梭式试验窑上采用成对的预混型调温高速烧嘴实现该技术,大幅度降低CO排放量,使该技术更为完善,有广阔的应用前景。     

NO x abatement by catalytic traps: on the mechanism of NO x trapping under automotive conditions

Topics in Catalysis - NO x adsorption was measured with a barium based NO x storage catalyst at an engine bench equipped with a lean burn gasoline direct injection engine (GDI). In order to study...     

燃烧装置中NOx的生成与抑制

分析形成光化学大气污染主要原因物质的NOx在燃烧装置中生成过程及机理。论述了为抑制NOx生成的各种燃烧改善对策：如降低燃烧温度、防止火焰中局部高温部的发生、燃烧后高温气体急冷等，力求从源头上控制光化学大气污染。     

The influence of NOx on the oxidation of metal activated diesel soot

The influence of NO on the oxidation of metal (cerium, copper, and iron)-activated soot was studied. Without NO in the gas phase, the activation energy of soot is ≈170 kJ/mol, independent of the type of metal applied in the soot. The rate-limiting step in the oxidation with oxygen is probably the decomposition of surface oxygen complexes. In presence of NO, the oxidation rate of soot mixed with a supported platinum catalyst is increased significantly, especially for cerium-activated soot. The activation energy of the oxidation reaction is decreased by the presence of NO in the gas phase. The increase in reaction rate as a result of NO and a platinum catalyst is explained by a cycle of two catalytic reactions, where platinum oxidises NO to NO₂, which subsequently oxidises soot using cerium as a catalyst, forming NO which can participate in the reaction more than once. This oxidation mechanism can be put into practice by combining a platinum-activated particulate trap with a combination of platinum and cerium fuel additives. This combination might be a breakthrough in the search for an applicable catalytic soot removal system.     

NO x adsorption study over Pt–Ba/alumina catalysts: FT-IR and reactivity study

Topics in Catalysis - The NO x storage process over Ba/Al2O3 and Pt–Ba/Al2O3 NSR catalysts has been analyzed in this study by performing experiments at 350&;nbsp;°C with NO2 and NO/O2...     

采用酸性尿素溶液作为吸收剂治理含NO_x尾气

作为填料塔常压下酸性尿素溶液还原NO_x 技术治理含NO_x尾气 ,避免了传统水洗法、碱吸收法、选择性催化氨还砂法等工艺存在的酸性污染水场、副反应多、副产品难于回收等问题 ,不会造成二次污染 ,并进行了工程实践。