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Sample records for catalytic nox removal

  1. Advances in catalytic removal of NOx under lean-burn conditions

    Institute of Scientific and Technical Information of China (English)

    LIU Zhiming; HAO Jiming; FU Lixin; LI Junhua; CUI Xiangyu

    2004-01-01

    The catalytic removal of NOx under lean conditions is one of the most important targets in catalysis research. The activities of metal oxides, zeolite-based catalysts and noble metal catalysts together with the factors are influencing the selective reduction of NOx with hydrocarbons are reviewed. The reaction mechanisms for the three types of catalysts are briefly discussed. Recent progress in combined catalyst and NOx storage reduction catalysts is also introduced. Finally, future research directions are forecasted.

  2. Simultaneously catalytic removal of NOx and particulate matter on diesel particulate filter

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The simultaneous removal of NOx and particulate matter (PM) exhausted from diesel engine was studied with a diesel particulate filter (DPF) on which a mixed metal oxide catalyst, Cu0.95K0.05Fe2O4 was loaded. The NOx reduction was observed in the same temperature range of the CO2 formation, implying the occurrence of the simultaneous removal of NOx and PM in an oxidizing atmosphere. It was shown that SOF and soot in PM are attributed to the reduction of NOx at lower and higher temperatures, respectively. The oxidation of PM was enhanced by the coexistence of NO and O2. The ignition and exhaustion temperatures of PM decrease as the order NO>O2>NO+O2. This is a combined process of PM trapping as well as the catalytic reactions of soot oxidation and NOx reduction, promising the most desirable after-treatment of diesel exhausts.

  3. Simultaneous catalytic removal of NOx and diesel soot particulate over perovskite-type oxides and supported Ag catalysts

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A series of perovskite-type oxides and supported Ag catalysts were prepared,and characterized by X-ray diffraction (XRD) and Xray photoelectron spectroscopy (XPS).The catalytic activities of the catalysts as well as influencing factors on catalytic activity have been investigated for the simultaneous removal of NOx and diesel soot particulate.An increase in catalytic activity for the selective reduction of NOx was observed with Ag addition in these perovskite oxides,especially with 5% Ag loading.This catalyst could be a promising candidate of catalytic material for the simultaneous elimination of NOx and diesel soot.

  4. NOX REMOVAL WITH COMBINED SELECTIVE CATALYTIC REDUCTION AND SELECTIVE NONCATALYTIC REDUCTION: PILOT- SCALE TEST RESULTS

    Science.gov (United States)

    Pilot-scale tests were conducted to develop a combined nitrogen oxide (NOx) reduction technology using both selective catalytic reduction (SCR) and selective noncatalytic reduction (SNCR). A commercially available vanadium-and titatnium-based composite honeycomb catalyst and enh...

  5. Sulfate Promoted Zirconia as Promising Alkali-Resistant Support for Catalytic NOx Removal

    OpenAIRE

    Due-Hansen, Johannes; Kustov, Arkadii; Christensen, Claus H.; Fehrmann, Rasmus

    2007-01-01

    The use of bio-fuels as alternatives to traditional fossil fuels has attracted much attention recent years since bio-fuels belong to a family of renewable types of energy sources and do not contribute to the green-house effect. Selective catalytic reduction (SCR) of NOx with ammonia as reductant is the most efficient method to eliminate NOx from flue gases in stationary sources. The traditional SCR catalyst suffers significant deactivation with time due to the presence of relative large amoun...

  6. Demonstration of an integrated catalytic SO2/NOx/particulate removal process

    International Nuclear Information System (INIS)

    A new technology for the integrated catalytic removal of SO2, NOx and particulate has been developed in Europe and will be demonstrated at the Ohio Edison Niles Plant - Unit 2 in Niles, Ohio as part of the Department of Energy Clean Coal Technology Program II. Two applications of this process, one 30 MW industrial and one 300 MW utility are currently under construction in Italy and Denmark, respectively. Pilot scale applications of this technology have yielded greater than 95% removal of both sulfur dioxide (SO2) and nitrogen oxides (NO4). Particulate emissions of less than 1 mg/Nm3 (0.0004 gr/SCF) are inherent to the process. Salable, technical grade sulfuric acid and usable heat are the only by-products. Ammonia, used to reduce nitrogen oxides, is the only reagent required. This demonstration project will treat a 35 MW equivalent slipstream from a 108 MW boiler burning 3.2% sulfur Ohio coal. The objectives of this four year project are to demonstrate the process using U.S. high sulfur coal, verify the scale-up potential of pilot plant results, further quantify and qualify the consumables and products of the process and verify the predicted low O and M costs. This paper describes the WSA-SNOX process and the Niles Demonstration project. The two-year testing program to assess the performance and economic competitiveness of the process is outlined and a brief discussion of estimated full-scale costs is also presented

  7. Sulfate Promoted Zirconia as Promising Alkali-Resistant Support for Catalytic NOx Removal

    DEFF Research Database (Denmark)

    Due-Hansen, Johannes; Kustov, Arkadii; Christensen, Claus H.;

    The use of bio-fuels as alternatives to traditional fossil fuels has attracted much attention recent years since bio-fuels belong to a family of renewable types of energy sources and do not contribute to the green-house effect. Selective catalytic reduction (SCR) of NOx with ammonia as reductant...

  8. Sulfated Zirconia as Alkali-Resistant Support for Catalytic NOx Removal

    DEFF Research Database (Denmark)

    The use of bio-fuels as alternatives to traditional fossil fuels has attracted much attention recent years since bio-fuels belong to a family of renewable types of energy sources and do not contribute to the green-house effect. Selective catalytic reduction (SCR) of NOx with ammonia as reductant...

  9. 微波加热技术在催化 NOx 脱除中的应用%Application of microwave heating technology in catalytic removal of NOx

    Institute of Scientific and Technical Information of China (English)

    刘艳春; 郭亚琴; 曾令可; 王慧; 任雪谭

    2014-01-01

    The types,harm and removal methods of nitrogen oxides in the air were summarized. Nitrogen oxides mainly consisted of NO,N2 O and NO2 ,which were produced by the combustion of fossil fuel and plants,and the conversion of nitrogen compounds in animal waste and the soil. NOx was one of major for-mation causes of acid rain and the smog,which had a serious influence on the health of human beings. Selective catalytic reduction technology based on the interaction of reducing agents such as ammonia and catalysts could make NOx into N2 and H2 O,while non-selective catalytic reduction technology achieved the removal of NOx with reducing agents such as ammonia at high temperature. However,the traditional techniques for removing NOx had shortcomings of low removal efficiency and easy production of secondary pollution. Microwave discharge technology could directly decompose NOx to N2 by producing high-energy electrons,and microwave carbon thermal reduction technology could significantly improve NOx removal ability by utilizeing thermal effects of microwave irradiation on active charcoal. The removal efficiency of NO was more than 96% . The application researches on microwave relating to de-NOx technology in com-mercial catalytic denitrification field showed that the combination of catalysts,microwave and other tech-niques was an ideal way of removing the nitrogen oxides,which had a good application prospect.%综述了空气中氮氧化物的类型、危害及脱除方法。空气中氮氧化物主要为 NO、N2 O 和NO2,化石燃料和植物体的燃烧以及土壤和动物排泄物中含氮化合物的转化是其主要来源,NOx 是酸雨和雾霾天气形成的主要原因之一,严重影响人类健康。选择性催化还原技术通过氨等还原剂和催化剂的共同作用将 NOx 还原成 N2和 H2 O,选择性非催化还原技术利用氨等还原剂在高温环境下的还原能力实现 NOx 的脱除。传统 NOx 脱除技术存在脱除效率不高和

  10. One-pot hydrothermal synthesis of CuBi co-doped mesoporous zeolite Beta for the removal of NOx by selective catalytic reduction with ammonia

    Science.gov (United States)

    Xie, Zhiguo; Zhou, Xiaoxia; Wu, Huixia; Chen, Lisong; Zhao, Han; Liu, Yan; Pan, Linyu; Chen, Hangrong

    2016-07-01

    A series of CuBi co-doped mesoporous zeolite Beta (CuxBiy-mBeta) were prepared by a facile one-pot hydrothermal treatment approach and were characterized by XRD, N2 adsorption-desorption, TEM/SEM, XPS, H2-TPR, NH3-TPD and in situ DRIFTS. The catalysts CuxBiy-mBeta were applied to the removal of NOx by selective catalytic reduction with ammonia (NH3-SCR), especially the optimized Cu1Bi1-mBeta achieved the high efficiency for the removal of NOx and N2 selectivity, superior water and sulfur resistance as well as good durability. The excellent catalytic performance could be attributed to the acid sites of the support and the synergistic effect between copper and bismuth species. Moreover, in situ DRIFTS results showed that amides NH2 and NH4+ generated from NH3 adsorption could be responsible for the high selective catalytic reduction of NOx to N2. In addition, a possible catalytic reaction mechanism on Cu1Bi1-mBeta for the removal of NOx by NH3-SCR was proposed for explaining this catalytic process.

  11. One-pot hydrothermal synthesis of CuBi co-doped mesoporous zeolite Beta for the removal of NOx by selective catalytic reduction with ammonia.

    Science.gov (United States)

    Xie, Zhiguo; Zhou, Xiaoxia; Wu, Huixia; Chen, Lisong; Zhao, Han; Liu, Yan; Pan, Linyu; Chen, Hangrong

    2016-01-01

    A series of CuBi co-doped mesoporous zeolite Beta (CuxBiy-mBeta) were prepared by a facile one-pot hydrothermal treatment approach and were characterized by XRD, N2 adsorption-desorption, TEM/SEM, XPS, H2-TPR, NH3-TPD and in situ DRIFTS. The catalysts CuxBiy-mBeta were applied to the removal of NOx by selective catalytic reduction with ammonia (NH3-SCR), especially the optimized Cu1Bi1-mBeta achieved the high efficiency for the removal of NOx and N2 selectivity, superior water and sulfur resistance as well as good durability. The excellent catalytic performance could be attributed to the acid sites of the support and the synergistic effect between copper and bismuth species. Moreover, in situ DRIFTS results showed that amides NH2 and NH4(+) generated from NH3 adsorption could be responsible for the high selective catalytic reduction of NOx to N2. In addition, a possible catalytic reaction mechanism on Cu1Bi1-mBeta for the removal of NOx by NH3-SCR was proposed for explaining this catalytic process. PMID:27445009

  12. One-pot hydrothermal synthesis of CuBi co-doped mesoporous zeolite Beta for the removal of NOx by selective catalytic reduction with ammonia

    Science.gov (United States)

    Xie, Zhiguo; Zhou, Xiaoxia; Wu, Huixia; Chen, Lisong; Zhao, Han; Liu, Yan; Pan, Linyu; Chen, Hangrong

    2016-01-01

    A series of CuBi co-doped mesoporous zeolite Beta (CuxBiy-mBeta) were prepared by a facile one-pot hydrothermal treatment approach and were characterized by XRD, N2 adsorption-desorption, TEM/SEM, XPS, H2-TPR, NH3-TPD and in situ DRIFTS. The catalysts CuxBiy-mBeta were applied to the removal of NOx by selective catalytic reduction with ammonia (NH3-SCR), especially the optimized Cu1Bi1-mBeta achieved the high efficiency for the removal of NOx and N2 selectivity, superior water and sulfur resistance as well as good durability. The excellent catalytic performance could be attributed to the acid sites of the support and the synergistic effect between copper and bismuth species. Moreover, in situ DRIFTS results showed that amides NH2 and NH4+ generated from NH3 adsorption could be responsible for the high selective catalytic reduction of NOx to N2. In addition, a possible catalytic reaction mechanism on Cu1Bi1-mBeta for the removal of NOx by NH3-SCR was proposed for explaining this catalytic process. PMID:27445009

  13. Simultaneous Removal of NOx and Mercury in Low Temperature Selective Catalytic and Adsorptive Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Neville G. Pinto; Panagiotis G. Smirniotis

    2006-03-31

    The results of a 18-month investigation to advance the development of a novel Low Temperature Selective Catalytic and Adsorptive Reactor (LTSCAR), for the simultaneous removal of NO{sub x} and mercury (elemental and oxidized) from flue gases in a single unit operation located downstream of the particulate collectors, are reported. In the proposed LTSCAR, NO{sub x} removal is in a traditional SCR mode but at low temperature, and, uniquely, using carbon monoxide as a reductant. The concomitant capture of mercury in the unit is achieved through the incorporation of a novel chelating adsorbent. As conceptualized, the LTSCAR will be located downstream of the particulate collectors (flue gas temperature 140-160 C) and will be similar in structure to a conventional SCR. That is, it will have 3-4 beds that are loaded with catalyst and adsorbent allowing staged replacement of catalyst and adsorbent as required. Various Mn/TiO{sub 2} SCR catalysts were synthesized and evaluated for their ability to reduce NO at low temperature using CO as the reductant. It has been shown that with a suitably tailored catalyst more than 65% NO conversion with 100% N{sub 2} selectivity can be achieved, even at a high space velocity (SV) of 50,000 h-1 and in the presence of 2 v% H{sub 2}O. Three adsorbents for oxidized mercury were developed in this project with thermal stability in the required range. Based on detailed evaluations of their characteristics, the mercaptopropyltrimethoxysilane (MPTS) adsorbent was found to be most promising for the capture of oxidized mercury. This adsorbent has been shown to be thermally stable to 200 C. Fixed-bed evaluations in the targeted temperature range demonstrated effective removal of oxidized mercury from simulated flue gas at very high capacity ({approx}>58 mg Hg/g adsorbent). Extension of the capability of the adsorbent to elemental mercury capture was pursued with two independent approaches: incorporation of a novel nano-layer on the surface of the

  14. Simultaneous catalytic removal of NOx and diesel PM over La0.9 K0.1 CoO3 catalyst assisted by plasma

    Institute of Scientific and Technical Information of China (English)

    PEI Mei-xiang; LIN He; SHANGGUAN Wen-feng; HUANG Zhen

    2005-01-01

    The simultaneous removal of NOx and particulate matter(PM) from diesel exhaust is investigated over a mixed metal oxide catalyst of La0.9 K0.1 CoO3 loaded on γ-Al2O3 spherules with the assistant of plasma. It was found that NOx was reduced by PM in oxygen rich atmosphere, the CO2 and N2 were produced in the same temperature window without considering the N2 formed by plasma decomposition. As a result, the temperature for the PM combustion decreases and the reduction efficiency of NOx to N2 increases during the plasma process, which indicated that the activity of the catalyst can be improved by plasma. The NOx is decomposed by plasma at both low temperature and high temperature. Therefore, the whole efficiency of NOx conversion is enhanced.

  15. Catalytic treatment of diesel engines, NOx emissions

    International Nuclear Information System (INIS)

    Some aspects of the operation of diesel engines are revised together with the pollutant emissions they produce, as well as the available catalytic technologies for the treatment of diesel emissions. Furthermore the performance of a catalyst developed in the environmental catalysis group for NOx reduction using synthetic gas mixtures simulating the emissions from diesel engines is presented

  16. A study on the catalytic activity of new catalysts for removal of NOx, CH and CO emitted from car exhaust

    Directory of Open Access Journals (Sweden)

    Y. Walid Bizreh

    2014-10-01

    Full Text Available Three catalysts were prepared from copper oxide carried on a matrix of a mixture of Syrian, Jordanian natural zeolite, Syrian bentonite, and Al2O3–CuO. As a simulation to the field motor car condition, a good quantity of macrosize granules of the catalyst was used, and the initial reacting agents were the car exhaust gases (C.E.G.. Catalytic experiments were conducted by means of a flow micro pulse–like reactor using the gases emitted from car exhaust. When the (ZJB–CuO, Al2O3–CuO catalyst was applied, the maximal de-CO conversion was as estimated as 60% at 250 °C, and 90% for de-CH at 400 °C, whereas the de-CH rate conversion of the (ZB–CuO, Al2O3–MoO3–CuO catalyst was as much as 80% at 360 °C and 78% for de-CO at 360 °C. The catalytic data made it possible to suggest a mechanism for each of the ongoing reactions. A maximal de-CH, conversion rate on the (ZB–CuO, Al2O3–CuO catalyst was reached at 450 °C. The N2 adsorption–desorption measurements were carried out at (−196 °C, thermal analysis, and X-ray diffraction for the catalysts were studied as well. A comparative study was conducted between the catalysts [(ZB–CuO, Al2O3–MoO3–CuO, and (ZJB–CuO, Al2O3–CuO] and a honeycomb structure commercial catalyst manufactured for use in gasoline vehicles.

  17. Chemically enhanced biological NOx removal from flue gases : nitric oxide and ferric EDTA reduction in BioDeNox reactors

    OpenAIRE

    Maas,, F.

    2005-01-01

    The emission of nitrogen oxides (NOx) to the atmosphere is a major environmental problem. To abate NOx emissions from industrial flue gases, to date, mainly chemical processes like selective catalytic reduction (SCR) are applied. All these processes require high temperatures (>300 °C) and expensive catalysts. Therefore, biological NOx removal techniques using denitrification may represent promising alternatives for the conventional SCR techniques. However, water based biofiltration require...

  18. HYBRID SELECTIVE NON-CATALYTIC REDUCTION (SNCR)/SELECTIVE CATALYTIC REDUCTION (SCR) DEMONSTRATION FOR THE REMOVAL OF NOx FROM BOILER FLUE GASES; FINAL

    International Nuclear Information System (INIS)

    The U. S. Department of Energy (DOE), Electric Power Research Institute (EPRI), Pennsylvania Electric Energy Research Council, (PEERC), New York State Electric and Gas and GPU Generation, Inc. jointly funded a demonstration to determine the capabilities for Hybrid SNCR/SCR (Selective Non-Catalytic Reduction/Selective Catalytic Reduction) technology. The demonstration site was GPU Generation's Seward Unit No.5 (147MW) located in Seward Pennsylvania. The demonstration began in October of 1997 and ended in December 1998. DOE funding was provided through Grant No. DE-FG22-96PC96256 with T. J. Feeley as the Project Manager. EPRI funding was provided through agreements TC4599-001-26999 and TC4599-002-26999 with E. Hughes as the Project Manager. This project demonstrated the operation of the Hybrid SNCR/SCR NO(sub x) control process on a full-scale coal fired utility boiler. The hybrid technology was expected to provide a cost-effective method of reducing NO(sub x) while balancing capital and operation costs. An existing urea based SNCR system was modified with an expanded-duct catalyst to provide increased NO(sub x) reduction efficiency from the SNCR while producing increased ammonia slip levels to the catalyst. The catalyst was sized to reduce the ammonia slip to the air heaters to less than 2 ppm while providing equivalent NO(sub x) reductions. The project goals were to demonstrate hybrid technology is capable of achieving at least a 55% reduction in NO(sub x) emissions while maintaining less than 2ppm ammonia slip to the air heaters, maintain flyash marketability, verify the cost benefit and applicability of Hybrid post combustion technology, and reduce forced outages due to ammonium bisulfate (ABS) fouling of the air heaters. Early system limitations, due to gas temperature stratification, restricted the Hybrid NO(sub x) reduction capabilities to 48% with an ammonia slip of 6.1 mg/Nm(sup 3) (8 ppm) at the catalyst inlet. After resolving the stratification problem

  19. HYBRID SELECTIVE NON-CATALYTIC REDUCTION (SNCR)/SELECTIVE CATALYTIC REDUCTION (SCR) DEMONSTRATION FOR THE REMOVAL OF NOx FROM BOILER FLUE GASES

    Energy Technology Data Exchange (ETDEWEB)

    Jerry B. Urbas

    1999-05-01

    The U. S. Department of Energy (DOE), Electric Power Research Institute (EPRI), Pennsylvania Electric Energy Research Council, (PEERC), New York State Electric and Gas and GPU Generation, Inc. jointly funded a demonstration to determine the capabilities for Hybrid SNCR/SCR (Selective Non-Catalytic Reduction/Selective Catalytic Reduction) technology. The demonstration site was GPU Generation's Seward Unit No.5 (147MW) located in Seward Pennsylvania. The demonstration began in October of 1997 and ended in December 1998. DOE funding was provided through Grant No. DE-FG22-96PC96256 with T. J. Feeley as the Project Manager. EPRI funding was provided through agreements TC4599-001-26999 and TC4599-002-26999 with E. Hughes as the Project Manager. This project demonstrated the operation of the Hybrid SNCR/SCR NO{sub x} control process on a full-scale coal fired utility boiler. The hybrid technology was expected to provide a cost-effective method of reducing NO{sub x} while balancing capital and operation costs. An existing urea based SNCR system was modified with an expanded-duct catalyst to provide increased NO{sub x} reduction efficiency from the SNCR while producing increased ammonia slip levels to the catalyst. The catalyst was sized to reduce the ammonia slip to the air heaters to less than 2 ppm while providing equivalent NO{sub x} reductions. The project goals were to demonstrate hybrid technology is capable of achieving at least a 55% reduction in NO{sub x} emissions while maintaining less than 2ppm ammonia slip to the air heaters, maintain flyash marketability, verify the cost benefit and applicability of Hybrid post combustion technology, and reduce forced outages due to ammonium bisulfate (ABS) fouling of the air heaters. Early system limitations, due to gas temperature stratification, restricted the Hybrid NO{sub x} reduction capabilities to 48% with an ammonia slip of 6.1 mg/Nm{sup 3} (8 ppm) at the catalyst inlet. After resolving the stratification

  20. Removal of NOx by radical injection

    Institute of Scientific and Technical Information of China (English)

    LIN He; GAO Xiang; LUO Zhongyang; CEN Kefa; PEI Meixiang; HUANG Zhen

    2004-01-01

    Removal of NOx ( DeNOx, NOx is the total of NO and NO2) from flue gas by radical injection has been investigated . The discharge characteristics were examined and the steady streamer corona was acquired by adjusting the nozzle gases properly. It was found that an increase in the voltage resulted in a decrease in the NO concentration and the concentration of the NO2 increased at low voltages but decreased as the voltage rose to a certain level. The DeNOx efficiency increased as the applied voltage rose and reached a maximum of 70% when the voltage approached the breakdown voltage. The hypothetical mechanism of NOx removal suggested that the radicals formed in the discharge process converted the NO and NO2 into acidic species. The Monte Carlo method was used to calculate the rate coefficients and the productivity of the radicals, and then the concentrations of both NO and NO2 and the DeNOx efficiencies were calculated with chemical kinetics. The calculated DeNOx efficiencies were comparable with the experimental DeNOx efficiencies at low voltages, but were lower at high voltages.

  1. Studies on Nitrogen Oxides Removal Using Plasma Assisted Catalytic Reactor

    Institute of Scientific and Technical Information of China (English)

    V. Ravi; Young Sun Mok; B. S. Rajanikanth; Ho-Chul Kang

    2003-01-01

    An electric discharge plasma reactor combined with a catalytic reactor was studied for removing nitrogen oxides. To understand the combined process thoroughly, discharge plasma and catalytic process were separately studied first, and then the two processes were combined for the study. The plasma reactor was able to oxidize NO to NO2 well although the oxidation rate decreased with temperature. The plasma reactor alone did not reduce the NOx (NO+NO2)level effectively, but the increase in the ratio of NO2 to NO as a result of plasma discharge led to the enhancement of NOx removal efficiency even at lower temperatures over the catalyst surface (V2O5-WOa/TiO2). At a gas temperature of 100℃, the NOx removal efficiency obtained using the combined plasma catalytic process was 88% for an energy input of 36 eV/molecule or 30 J/1.

  2. Hydrophobic Catalysts For Removal Of NOx From Flue Gases

    Science.gov (United States)

    Sharma, Pramod K.; Hickey, Gregory S.; Voecks, Gerald E.

    1995-01-01

    Improved catalysts for removal of nitrogen oxides (NO and NO2) from combustion flue gases formulated as composites of vanadium pentoxide in carbon molecular sieves. Promotes highly efficient selective catalytic reduction of NOx at relatively low temperatures while not being adversely affected by presence of water vapor and sulfur oxide gases in flue gas. Apparatus utilizing catalyst of this type easily integrated into exhaust stream of power plant to remove nitrogen oxides, generated in combustion of fossil fuels and contribute to formation of acid rain and photochemical smog.

  3. Integrated Removal of NOx with Carbon Monoxide as Reductant, and Capture of Mercury in a Low Temperature Selective Catalytic and Adsorptive Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Neville Pinto; Panagiotis Smirniotis; Stephen Thiel

    2010-08-31

    Coal will likely continue to be a dominant component of power generation in the foreseeable future. This project addresses the issue of environmental compliance for two important pollutants: NO{sub x} and mercury. Integration of emission control units is in principle possible through a Low Temperature Selective Catalytic and Adsorptive Reactor (LTSCAR) in which NO{sub x} removal is achieved in a traditional SCR mode but at low temperature, and, uniquely, using carbon monoxide as a reductant. The capture of mercury is integrated into the same process unit. Such an arrangement would reduce mercury removal costs significantly, and provide improved control for the ultimate disposal of mercury. The work completed in this project demonstrates that the use of CO as a reductant in LTSCR is technically feasible using supported manganese oxide catalysts, that the simultaneous warm-gas capture of elemental and oxidized mercury is technically feasible using both nanostructured chelating adsorbents and ceria-titania-based materials, and that integrated removal of mercury and NO{sub x} is technically feasible using ceria-titania-based materials.

  4. Optimization of an electrochemical cell with an adsorption layer for NOx removal

    DEFF Research Database (Denmark)

    Shao, Jing; Kammer Hansen, Kent

    2012-01-01

    The structure of a multilayer electrochemical cell with an adsorption layer was optimized by removing an yttriastabilized zirconia cover layer. It was found that the NOx removal properties of the electrochemical cell were dramatically enhanced through the optimization, especially under conditions...... of low voltage, intermediate temperature, and high O2 concentration. The pronounced increase in activity and selectivity for NOx decomposition after removing the ytrriastabilized zirconia cover layer was attributed to the extensive release of selective reaction sites for NOx species and a strong...... promotion for NOx reduction from the interaction of the directly connected adsorption layer with both the Pt and catalytic layers. The optimized electrochemical cell may provide a promising solution for NOx emission control....

  5. AN EXPERIMENTAL STUDY ON REMOVAL OF NOX IN FLUE GAS AT THE NONEQUILIBRIUM PLASMA

    Institute of Scientific and Technical Information of China (English)

    张强; 许世森; 顾璠

    2004-01-01

    Removal of nitrogen oxides (NOX) in flue gas by means of nonequilibrium plasma technology is a very prospect and attractive method. As the nonequilibrium plasma micro discharges can generate a powerful energy flux, imparted to the flue gas, the molecules and atoms of pollutants are motivated and decomposed, and then NOX in the flue gas are decomposed and conversed in the particular conditions. Based on nonequilibrium plasma in combination with catalytic principle, an experimental investigation on NOX decomposition and conversion with Al2O3 catalysts was carried out and the NOX removal rate up to 95% was obtained. The NOX decomposition and conversion principle with Al2O3 catalysts was also discussed.

  6. Ultra Low NOx Catalytic Combustion for IGCC Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Shahrokh Etemad; Benjamin Baird; Sandeep Alavandi; William Pfefferle

    2008-03-31

    In order to meet DOE's goals of developing low-emissions coal-based power systems, PCI has further developed and adapted it's Rich-Catalytic Lean-burn (RCL{reg_sign}) catalytic reactor to a combustion system operating on syngas as a fuel. The technology offers ultra-low emissions without the cost of exhaust after-treatment, with high efficiency (avoidance of after-treatment losses and reduced diluent requirements), and with catalytically stabilized combustion which extends the lower Btu limit for syngas operation. Tests were performed in PCI's sub-scale high-pressure (10 atm) test rig, using a two-stage (catalytic then gas-phase) combustion process for syngas fuel. In this process, the first stage consists of a fuel-rich mixture reacting on a catalyst with final and excess combustion air used to cool the catalyst. The second stage is a gas-phase combustor, where the air used for cooling the catalyst mixes with the catalytic reactor effluent to provide for final gas-phase burnout and dilution to fuel-lean combustion products. During testing, operating with a simulated Tampa Electric's Polk Power Station syngas, the NOx emissions program goal of less than 0.03 lbs/MMBtu (6 ppm at 15% O{sub 2}) was met. NOx emissions were generally near 0.01 lbs/MMBtu (2 ppm at 15% O{sub 2}) (PCI's target) over a range on engine firing temperatures. In addition, low emissions were shown for alternative fuels including high hydrogen content refinery fuel gas and low BTU content Blast Furnace Gas (BFG). For the refinery fuel gas increased resistance to combustor flashback was achieved through preferential consumption of hydrogen in the catalytic bed. In the case of BFG, stable combustion for fuels as low as 88 BTU/ft{sup 3} was established and maintained without the need for using co-firing. This was achieved based on the upstream catalytic reaction delivering a hotter (and thus more reactive) product to the flame zone. The PCI catalytic reactor was also shown

  7. Catalytic Combustion for Ultra-Low NOx Hydrogen Turbines

    Energy Technology Data Exchange (ETDEWEB)

    Etemad, Shahrokh; Baird, Benjamin; Alavandi, Sandeep

    2011-06-30

    Precision Combustion, Inc., (PCI) in close collaboration with Solar Turbines, Incorporated, has developed and demonstrated a combustion system for hydrogen fueled turbines that reduces NOx to low single digit level while maintaining or improving current levels of efficiency and eliminating emissions of carbon dioxide. Full scale Rich Catalytic Hydrogen (RCH1) injector was developed and successfully tested at Solar Turbines, Incorporated high pressure test facility demonstrating low single digit NOx emissions for hydrogen fuel in the range of 2200F-2750F. This development work was based on initial subscale development for faster turnaround and reduced cost. Subscale testing provided promising results for 42% and 52% H2 with NOx emissions of less than 2 ppm with improved flame stability. In addition, catalytic reactor element testing for substrate oxidation, thermal cyclic injector testing to simulate start-stop operation in a gas turbine environment, and steady state 15 atm. operation testing were performed successfully. The testing demonstrated stable and robust catalytic element component life for gas turbine conditions. The benefit of the catalytic hydrogen combustor technology includes capability of delivering near-zero NOx without costly post-combustion controls and without requirement for added sulfur control. In addition, reduced acoustics increase gas turbine component life. These advantages advances Department of Energy (DOE’s) objectives for achievement of low single digit NOx emissions, improvement in efficiency vs. postcombustion controls, fuel flexibility, a significant net reduction in Integrated Gasification Combined Cycle (IGCC) system net capital and operating costs, and a route to commercialization across the power generation field from micro turbines to industrial and utility turbines.

  8. Selective catalytic reduction of NOx from diesel engine exhaust using injection of urea. Doctoral thesis

    Energy Technology Data Exchange (ETDEWEB)

    Hultermans, R.J.

    1995-09-25

    ;Contents: Diesel exhaust NOx formation and abatement (Diesel DeNOxing literature, System Considerations, Summary); Catalytic testing (Experimental facilities for testing catalysts, transport phenomena in steady state fixed bed reactors, Catalyst testing); Development of a urea injection system.

  9. COST OF SELECTIVE CATALYTIC REDUCTION (SCR) APPLICATION FOR NOX CONTROL ON COAL-FIRED BOILERS

    Science.gov (United States)

    The report provides a methodology for estimating budgetary costs associated with retrofit applications of selective catalytic reduction (SCR) technology on coal-fired boilers. SCR is a postcombustion nitrogen oxides (NOx) control technology capable of providing NOx reductions >90...

  10. Investigation of NOx Removal from Small Engine Exhaust

    Science.gov (United States)

    Akyurtlu, Ates; Akyurtlu, Jale F.

    1999-01-01

    Contribution of emissions from small engines to the air pollution is significant. Due to differences in operating conditions and economics, the pollution control systems designed for automobiles will be neither suitable nor economically feasible for use on small engines. The objective of this project was to find a catalyst for the removal of NOx from the exhaust of small engines which use a rich air to fuel ratio. The desired catalyst should be inexpensive so that the cost of the pollution control unit will be only a small fraction of the total equipment cost. The high cost of noble metals makes them too expensive for use as NOx catalyst for small engines. Catalytic reduction of Nitrogen Oxide (NO) can also be accomplished by base-metal oxide catalysts. The main disadvantage of base-metal catalysts is their deactivation by poisons and high temperatures. Requirements for the length of the life of the small engine exhaust catalysts are much less than those for automobile exhaust catalysts. Since there is no oxygen in the exhaust gases, reduction selectivity is not a problem. Also, the reducing exhaust gases might help prevent the harmful interactions of the catalyst with the support. For these reasons only the supported metal oxide catalysts were investigated in this project.

  11. Investigation of NO(x) Removal from Small Engine Exhaust

    Science.gov (United States)

    Akyurtlu, Ates; Akyurtlu, Jale F.

    1999-01-01

    Contribution of emissions from small engines to the air pollution is significant. Due to differences in operating conditions and economics, the pollution control systems designed for automobiles will be neither suitable nor economically feasible for use on small engines. The objective of this project was to find a catalyst for the removal of NOx from the exhaust of small engines which use a rich air to fuel ratio. The desired catalyst should be inexpensive so that the cost of the pollution control unit will be only a small fraction of the total equipment cost. The high cost of noble metals makes them too expensive for use as NOx catalyst for small engines. Catalytic reduction of NO can also be accomplished by base-metal oxide catalysts. The main disadvantage of base-metal catalysts is their deactivation by poisons and high temperatures. Requirements for the length of the life of the small engine exhaust catalysts are much less than those for automobile exhaust catalysts. Since there is no oxygen in the exhaust gases, reduction selectivity is not a problem. Also, the reducing exhaust gases might help prevent the harmful interactions of the catalyst with the support. For these reasons only the supported metal oxide catalysts were investigated in this project.

  12. 催化氧化法去除烟气中 NOx 的研究现状与展望%Research Status and Prospects of Using Catalytic Oxidation Method to Remove NOx in Flue Gas

    Institute of Scientific and Technical Information of China (English)

    张瑞元; 李凯; 宁平; 汤立红; 刘烨; 王驰

    2015-01-01

    综述了 SCO 法(选择性催化氧化法)中催化剂的研究现状。从过渡金属元素、稀土元素、贵金属、活性炭四类催化剂进行了介绍。锰类复合氧化物催化剂具有较高的催化活性,且成本较低。钙钛矿催化剂的催化活性能与贵金属类催化剂相媲美。这些非贵金属催化剂成本都较低,具有潜在的应用价值。但总的来说目前对于催化剂抗硫抗水的研究还不够深入,一些催化剂可能还未达到实际工业应用中应具有的抗中毒能力。总结分析了 SCO 法应用中存在的问题,展望了其应用前景。%The research status of the catalyst in the SCO method (Selective catalytic oxidation)were summa-rized.It introduces four kinds of catalysts,which including transition metal oxides,oxides of rare earth elements, precious metals,and activated carbon.The composite oxides catalysts of manganese exhibit good performance,which is cost-low.The activity of rare-earth perovskite structure catalysts can be comparable with that of noble metal cata-lysts.All these non-noble metal catalysts is cost-low,it has potential application value for industry.But now the re-search of poison tolerance of the catalysts is less,the tolerant ability for poisoning of the catalysts still could not reach the requirements of practical application.We also analyze the problems existing in the application of SCO and the out-look of the SCO method.

  13. Neutron studies of nanostructured CuO-Al2O3 NOx removal catalysts

    International Nuclear Information System (INIS)

    Nanostructured powders of automotive catalytic system CuO0Al2O3, targeted for nitrogen oxides (NOx) removal under lean-burn engine conditions, were investigated using neutron diffraction and small-angle neutron scattering. The crystal phases, structural transformations and microstructure of 10 mol% Cu-Al2O3 powders are characterized according to the heat-treatment conditions. These properties are correlated with the pore structure and NOx removal efficiency determined by nitrogen adsorption isotherm, electron spin resonance, and temperature programmed reaction measurements. The γ-(Cu, Al)2O3 phase and the mass-fractal-like aggregate of particles (size ∼ 26 nm) at annealing temperatures below 900 degrees C were found to be crucial to the high NOx removal performance. The transformation to bulk crystalline phases of α-Al2O3 + CuAl2O4 spinel above ∼1050 degrees C corresponds to a drastic drop of Nox removal efficiency. The usefulness of neutron-scattering techniques as well as their complementarity with other traditional methods of catalytic research are discussed

  14. Removal of NOx with radical injection caused by corona discharge

    Energy Technology Data Exchange (ETDEWEB)

    He Lin; Xiang Gao; Zhongyang Luo; Kefa Cen; Zhen Huang [Zhejiang University, Hangzhou (China). Institute for Thermal Power Energy

    2004-07-01

    Removal of NOx (namely DeNOx) from simulated flue gas with direct current (d.c.) corona radical shower system was investigated. Steady streamer coronas occur when the flow rates of the fed gases are adjusted properly. The experimental results show that both the composition and the flow rate of the gas fed into the nozzles influence the V-I characteristic of corona discharge. The vapor in the flue gas restrains the discharge, reduces the discharge current, but enhances the DeNOx efficiency. Furthermore, removal of NOx from flue gas by radical injection associated with alkali solution (26% by weight of NaOH in water) scrubbing was carried out. Oxygen together with water vapor is fed into the nozzle electrode and the oxygen and water molecules are decomposed in the corona zone. It is found that NO and NO{sub 2} can be converted into HNO{sub 2} and HNO{sub 3}, respectively, by radicals formed during the discharge process and the conversion efficiency of NOx in the plasma reactor is more than 60%. The overall DeNOx efficiency of the system reaches 81.7% after the flue gas was scrubbed by the NaOH solution. 11 refs., 15 figs., 2 tabs.

  15. 75 FR 6336 - Approval and Promulgation of Air Quality Implementation Plans; West Virginia; Removal of NOX

    Science.gov (United States)

    2010-02-09

    ...; Removal of NOX SIP Call Rules AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule... West Virginia that removes West Virginia's nitrogen oxides (NOx) SIP Call rules. In the Final...

  16. Congressionally Directed Project for Passive NOx Removal Catalysts Research

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, William

    2014-08-29

    The Recipient proposes to produce new scientific and technical knowledge and tools to enable the discovery and deployment of highly effective materials for the selective catalytic reduction (SCR) of nitrogen oxides (NOx) from lean combustion exhaust. A second goal is to demonstrate a closely coupled experimental and computational approach to heterogeneous catalysis research. These goals will be met through the completion of four primary technical objectives: First, an in-depth kinetic analysis will be performed on two prominent classes of NOx SCR catalysts, Fe- and Cu-exchanged beta and ZSM-5 zeolites, over a wide range of catalyst formulation and under identical, high conversion conditions as a function of gas phase composition. Second, the nanoscale structure and adsorption chemistry of these high temperature (HT) and low temperature (LT) catalysts will be determined using in situ and operando spectroscopy under the same reaction conditions. Third, first-principles molecular simulations will be used to model the metal-zeolite active sites, their adsorption chemistry, and key steps in catalytic function. Fourth, this information will be integrated into chemically detailed mechanistic and kinetic descriptions and models of the operation of these well- defined NOx SCR catalysts under practically relevant reaction conditions. The new knowledge and models that derive from this work will be published in the scientific literature.

  17. Selection of best impregnated palm shell activated carbon (PSAC) for simultaneous removal of SO2 and NOx

    International Nuclear Information System (INIS)

    This work examines the impregnated carbon-based sorbents for simultaneous removal of SO2 and NOx from simulated flue gas. The carbon-based sorbents were prepared using palm shell activated carbon (PSAC) impregnated with several metal oxides (Ni, V, Fe and Ce). The removal of SO2 and NOx from the simulated flue gas was investigated in a fixed-bed reactor. The results showed that PSAC impregnated with CeO2 (PSAC-Ce) reported the highest sorption capacity among other impregnated metal oxides for the simultaneous removal of SO2 and NOx. PSAC-Ce showed the longest breakthrough time of 165 and 115 min for SO2 and NOx, respectively. The properties of the pure and impregnated PSAC were analyzed by BET, FTIR and XRF. The physical-chemical features of the PSAC-Ce sorbent indicated a catalytic activity in both the sorption of SO2 and NOx. The formation of both sulfate (SO42-) and nitrate (NO3-) species on spent PSAC-Ce further prove the catalytic role played by CeO2.

  18. OPTIMIZATION OF CHAR FOR NOx REMOVAL; FINAL

    International Nuclear Information System (INIS)

    Work performed for this study demonstrates that the temperature of treatment and the identity of the treatment gas both strongly impact the surface chemistry of activated carbon. Two commercial activated carbons were treated in either N(sub 2) or H(sub 2) at different temperatures up to 2600 C. Several techniques-including microcalorimetry, point of zero charge measurements, thermal desorption-were used to provide insight into important aspects of the chemical surface properties. The results show that activated carbons treated at high temperatures (ca. 950 C) in hydrogen will not react with oxygen and water at ambient temperatures; moreover, surfaces created in this fashion have stable properties in ambient conditions for many months. In contrast, the same carbons treated in an inert gas (e.g., N(sub 2)) will react strongly with oxygen and water at ambient temperatures. In the presence of platinum (or any other noble metal), stable basic carbons, which will not adsorb oxygen in ambient laboratory conditions, can be created via a relatively low-temperature process. Treatment at higher temperatures ( and gt;1500 C) produced increasingly stable surfaces in either N(sub 2) or H(sub 2). A structural model is proposed. To wit: Treatment at high temperatures in any gas will lead to the desorption of oxygen surface functionalities in the form of CO and/or CO(sub 2). Absent any atom rearrangement, the desorption of these species will leave highly unsaturated carbon atoms (''dangling carbons'') on the surface, which can easily adsorb O(sub 2) and H(sub 2)O. In an inert gas these ''dangling carbons'' will remain, but hydrogen treatments will remove these species and leave the surface with less energetic sites, which can only adsorb O(sub 2) at elevated temperatures. Specifically, hydrogen reacts with any highly unsaturated carbons in the surface to form methane. At temperatures greater than 1500 C (e.g., 1800 C, 2600 C), structural annealing takes place and the consequent

  19. Selective catalytic reduction of NOx by hydrocarbons over Fe/ZSM5 prepared by sublimation of FeCl3

    OpenAIRE

    Battiston, A.A.

    2003-01-01

    Selective Catalytic Reduction of NOx by Hydrocarbons over Fe/ZSM5 Prepared by Sublimation of FeCl3. Characterization and Catalysis Nitrogen oxides (NOx) are unwanted by-products of combustion. They are generated primarily from motor vehicles and stationary sources, like power stations and industrial heaters. New catalytic materials are constantly developed in order to improve the efficiency of the cleaning-up technologies for NOx. With this respect an important breakthrough has recently been ...

  20. Low temperature selective catalytic reduction of NOx with NH3 over Mn-based catalyst: A review

    Directory of Open Access Journals (Sweden)

    TsungYu Lee

    2016-05-01

    Full Text Available The removals of NOx by catalytic technology at low temperatures (100–300 °C for industrial flue gas treatment have received increasing attention. However, the development of low temperature catalysts for selective catalytic reduction (SCR of NOx with ammonia is still a challenge especially in the presence of SO2. The current status of using Mn-based catalysts for low temperature SCR of NOx with ammonia (NH3-SCR is reviewed. Reaction mechanisms and effects of operating factors on low temperature NH3-SCR are addressed, and the SCR efficiencies of Mn-based metal oxides with and without SO2 poisoning have also been discussed with different supports and co-metals. The key factors for enhancing low temperature NH3-SCR efficiency and SO2 resistance with Mn-based catalysts are identified to be (1 high specific surface area; (2 high surface acidity; (3 oxidation states of manganese; (4 well dispersion of manganese oxide metals; (5 more surface adsorbed oxygen; (6 more absorbed NO3− on the catalyst surface; (7 easier decomposition of ammonium sulfates. Moreover, the regenerative methods such as water washing, acid and/or alkali washing and heat treatment to the poisoned catalysts could help to recover the low temperature SCR efficiency to its initial level.

  1. Effect of oxygen on NOx removal in corona discharge field: NOx behavior without a reducing agent

    Energy Technology Data Exchange (ETDEWEB)

    M. Arai; M. Saito; S. Yoshinaga [Gunma University, Gunma (Japan). Department of Mechanical System Engineering

    2004-10-01

    A DeNOx process using a DC corona discharge was investigated experimentally. A mixture system of N{sub 2}/O{sub 2}/NO was used as a test gas. The compositions such as NO, NO{sub 2}, N{sub 2}O and so on were analyzed with Fourier transform infrared spectroscopy and an NOx meter. It was found that the characteristics of NO removal by corona discharge differed remarkably whether or not oxygen exists in the mixture. In regard to the spectrum of light emission from the corona discharge in N{sub 2} atmosphere or N{sub 2}/O{sub 2} mixture, some N{sub 2} bands were detected. N{sub 2} dissociation into atomic N and N{sub 2} radical in the corona discharge field was conjectured. Furthermore, ozone was yielded by the corona discharge in the case of the N{sub 2}/O{sub 2} mixture. Ozone gas from an ozonizer was added into the N{sub 2}/O{sub 2} mixture without corona discharge to investigate the effect of O{sub 3} on the characteristics of NOx removal by corona discharge. In the case of the N{sub 2}/NO mixture, the process of NO reduction was mainly controlled by N{sub 2} radicals excited by the corona discharge. On the other hand, in the case of the N{sub 2}/O{sub 2}/NO mixture, NO was oxidized by ozone generated from the corona discharge and converted to NO{sub 2} and N{sub 2}O{sub 5}.

  2. INVESTIGATION OF SELECTIVE CATALYTIC REDUCTION IMPACT ON MERCURY SPECIATION UNDER SIMULATED NOX EMISSION CONTROL CONDITIONS

    Science.gov (United States)

    Selective catalytic reduction (SCR) technology is being increasingly applied for controlling emissions of nitrogen oxides (NOx) from coal-fired boilers. Some recent field and pilot studies suggest that the operation of SCR could affect the chemical form of mercury in the coal com...

  3. INDUSTRIAL BOILER RETROFIT FOR NOX CONTROL: COMBINED SELECTIVE NONCATALYTIC REDUCTION AND SELECTIVE CATALYTIC REDUCTION

    Science.gov (United States)

    The paper describes retrofitting and testing a 590 kW (2 MBtu/hr), oil-fired, three-pass, fire-tube package boiler with a combined selective noncatalytic reduction (SNCR) and selective catalytic reduction (SCR) system. The system demonstrated 85% nitrogen oxides (NOx) reduction w...

  4. Bauxite-supported Transition Metal Oxides: Promising Low-temperature and SO2-tolerant Catalysts for Selective Catalytic Reduction of NOx

    OpenAIRE

    Xiuyun Wang; Wen Wu; Zhilin Chen; Ruihu Wang

    2015-01-01

    In order to develop low-temperature (below 200 °C) and SO2-tolerant catalysts for selective catalytic reduction (SCR) of NOx, a series of cheap M/bauxite (M = Mn, Ni and Cu) catalysts were prepared using bauxite as a support. Their SCR performances are much superior to typical V2O5/TiO2, the addition of M into bauxite results in significant promotion of NOx removal efficiency, especially at low temperature. Among the catalysts, Cu/bauxite exhibits wide temperature window over 50–400 °C, stron...

  5. DEVELOPMENT OF HIGH ACTIVITY, CATALYTIC SYSTEMS FOR NOx REDUCTION

    Energy Technology Data Exchange (ETDEWEB)

    Unknown

    2001-12-01

    This project was directed at an investigation of catalytic NO{sub x} reduction on carbonaceous supports at low temperatures. The experimental work was conducted primarily in a packed bed reactor/gas flow system that was constructed for this work. The analytical techniques employed were mass spectrometry, NO{sub x} chemiluminescence, and gas chromatography. The experimental plan was focused on steady-state reactivity experiments, followed by temperature programmed desorption (TPD) of surface intermediates, and also selected temperature-programmed reaction (TPR) experiments. Both uncatalyzed and catalyzed (potassium-promoted) phenolic resin char, were investigated as well as the catalytic effect of additional CO in the gas phase.

  6. Modelling of NOx removal by a pulsed microwave discharge

    International Nuclear Information System (INIS)

    A kinetic model is developed to study NOx removal in N2/O2/NO gas mixtures treated by a pulsed microwave discharge at atmospheric pressure. The model considers the coupling between electronic, vibrational and chemical kinetics, taking into account a large set of neutral, excited and charged species. The time behaviour of the species densities is calculated for the given input parameters, namely the reduced electric field, the initial gas composition (N2, 500 ppm NO and 0%, 2%, 5% O2), the effective pulse duration (1.5 us) and repetition rate (40 Hz), and the gas temperature. The rate coefficients of the processes considered are either calculated from the electron energy distribution function or taken from published data. The vibrational temperature of N2 is derived from the calculated population densities of the first two vibrational levels of N2, and the results obtained are compared with those observed by coherent anti-Stokes Raman scattering (CARS) technique. The experimental data from the FTIR measurements of the NOx densities after reduction agree well with the calculations. (author)

  7. Low-level NOx removal in ambient air by pulsed corona technology

    Science.gov (United States)

    Beckers, F. J. C. M.; Hoeben, W. F. L. M.; Pemen, A. J. M.; van Heesch, E. J. M.

    2013-07-01

    Although removal of NOx by (pulsed) corona discharges has been thoroughly investigated for high concentrations of NOx in flue gas, removal of low levels in ambient air proves to be a difficult task. (Sub) ppm NOx levels exist in traffic tunnels due to accumulation of exhaust gases. The application of pulsed corona technology for purification of traffic tunnel air is studied during a series of lab and field experiments. An industrial pilot scale wire-cylinder type corona reactor has been utilized. Lab tests have been carried out using a diesel generator as NOx source. NOx conversion levels have been determined by applying two Recordum Airpointers (chemiluminescence-based detection). The detector appeared to be cross-sensitive for HNO3 and high levels of O3. NOx removal rates of 60-80% were obtained for inlet levels of 2-10 ppm. The SIE value of 10 ppm NOx removal is 7 J l-1. The corona discharges produce ppm level NOx at high energy densities. This intrinsic NOx production limits removal of inlet levels due to equilibrium between production and oxidation.

  8. Selective catalytic reduction of NOx by hydrocarbons over Fe/ZSM5 prepared by sublimation of FeCl3

    NARCIS (Netherlands)

    Battiston, A.A.

    2003-01-01

    Selective Catalytic Reduction of NOx by Hydrocarbons over Fe/ZSM5 Prepared by Sublimation of FeCl3. Characterization and Catalysis Nitrogen oxides (NOx) are unwanted by-products of combustion. They are generated primarily from motor vehicles and stationary sources, like power stations and indust

  9. Removal of NOx by pulsed, intense relativistic electron beam in distant gas chamber

    International Nuclear Information System (INIS)

    Removal of NOx has been studied using a pulsed, intense relativistic electron beam (IREB). The dependence of NOx concentration and the removal efficiency of NOx on the number of IREB shot have been investigated within a distant gas chamber spatially isolated from the electron beam source. The distant gas chamber is filled up with a dry-air-balanced NO gas mixture with the pressure of 270 kPa, and is irradiated by the IREB (2 MeV, 30 A, 35 ns) passing through a 1.6-m-long atmosphere. With the initial NO concentration of 88 ppm, ∼ 70 % of NOx is successfully removed by firing 10 shots of IREB. The NOx removal efficiency has been found to be 50-155 g/kWh

  10. On board catalytic NOx control: mechanistic aspects of the regeneration of Lean NOx Traps with H2

    International Nuclear Information System (INIS)

    Mechanistic aspects of the reduction with H2 of NOx stored on Lean NOx Trap catalysts are critically reviewed. It was shown that, under nearly isothermal conditions nitrogen formation occurs via an in series two-step process involving the participation of ammonia as an intermediate. The first step of this process is ammonia formation through the reaction of H2 with stored nitrates; ammonia then reacts with the nitrates left on the catalysts surface leading to the formation of nitrogen. Over the investigated Ba-containing catalysts, the first step (i.e. NH3 formation) is much faster than the second one which, therefore, is rate determining in the formation of nitrogen. Both steps are catalyzed by Pt and, under nearly isothermal conditions, do not involve the occurrence of a thermal decomposition step of the stored nitrates. Due to the fast reaction of the adsorbed nitrates with H2 to give ammonia and to the integral behaviour of the trap, an H2 front develops in the trap which travels along the reactor axis. Ammonia formed upon reaction of nitrates with H2 reacts downstream of the H2 front with nitrates leading to N2 formation, if the temperature is high enough. This explains both the observed change in the selectivity of the process with time upon regeneration of the trap (with selectivity changing from N2 to NH3), and the increase in the N2 selectivity with temperature as well. The identification of the pathway for the reduction of stored NOx, where ammonia is suggested as the intermediate product in the formation of nitrogen, may favour the improvement of the combined NSR + SCR technology that has been proposed by several car manufacturers to make NOx removal by NSR more effective and to simultaneously limit the ammonia slip (GB)

  11. NOx removal using the characteristics of radiation nuclear instrumentation and reactor control laboratory

    International Nuclear Information System (INIS)

    NOx removal by electric discharge was practiced by using both alpha-ray and sponge-Ti. Alpha-ray is easy to generate electron multiplication in order to supply plenty of primary electrons in the field of low applied voltage. Accordingly, it can removal NOx from the transfer resources by arranging many alpha-ray sources. By using it with sponge-Ti, which adsorbs activated substances, NOx was removed efficiently. The experimental system, method, results and discussion are reported. (S.Y.)

  12. NOx selective catalytic reduction at high temperatures with mixed oxides derived from layered double hydroxides

    OpenAIRE

    Palomares Gimeno, Antonio Eduardo; Franch Martí, Cristina; Ribera, Antonio; Abellán, G.

    2012-01-01

    Mixed oxides derived from layered double hydroxides (LDHs) have been investigated as potential catalysts for the NOx removal at high temperatures. The best results were obtained with Co–Al mixed oxides derived from LDHs that are active at 750 ◦C in the presence of oxygen and water. These catalysts could reduce or/and decompose the NOx formed in the dense phase of the FCC regenerator, being deactivated at oxygen concentrations higher than 1.5%. Nevertheless this deactivation is not...

  13. Selective catalytic reduction operation with heavy fuel oil: NOx, NH3, and particle emissions.

    Science.gov (United States)

    Lehtoranta, Kati; Vesala, Hannu; Koponen, Päivi; Korhonen, Satu

    2015-04-01

    To meet stringent NOx emission limits, selective catalytic reduction (SCR) is increasingly utilized in ships, likely also in combination with low-priced higher sulfur level fuels. In this study, the performance of SCR was studied by utilizing NOx, NH3, and particle measurements. Urea decomposition was studied with ammonia and isocyanic acid measurements and was found to be more effective with heavy fuel oil (HFO) than with light fuel oil. This is suggested to be explained by the metals found in HFO contributing to metal oxide particles catalyzing the hydrolysis reaction prior to SCR. At the exhaust temperature of 340 °C NOx reduction was 85-90%, while at lower temperatures the efficiency decreased. By increasing the catalyst loading, the low temperature behavior of the SCR was enhanced. The drawback of this, however, was the tendency of particle emissions (sulfate) to increase at higher temperatures with higher loaded catalysts. The particle size distribution results showed high amounts of nanoparticles (in 25-30 nm size), the formation of which SCR either increased or decreased. The findings of this work provide a better understanding of the usage of SCR in combination with a higher sulfur level fuel and also of ship particle emissions, which are a growing concern.

  14. Achieving Better NOx Removal in Discharge Plasma Reactor by Field Enhancement

    Institute of Scientific and Technical Information of China (English)

    B.S.RAJANIKANTH; Dipanwita SINHA

    2008-01-01

    Application of plasma chemistry for gas cleaning is gaining prominence in recent years, mainly from an energy efficiency point of view. In this paper we conducted a comparative study of NO/NOx removal using two different types of dielectric barrier discharge electrodes, wirecylinder reactor, pipe-cylinder reactor. Investigations were first carried out with synthetic gases to obtain the baseline information on the NO/NOx removal with respect to the two geometries studied. Further, experiments were carried out with raw diesel exhaust under loaded condition. A high NOx removal efficiency of 90% was observed for the pipe-cylinder reactor as compared to that of 53.4% for t-he wire-cylinder reactor. Furthermore, for the same energy consumed per NO molecule (about 73 eV/NO molecule), the removal efficiency increased from 67% for the wirecylinder to about 98% for the pipe-cylinder which was quite appreciable.

  15. Simultaneous removal of SO{sub 2} and NOx by wet scrubbing using urea solution

    Energy Technology Data Exchange (ETDEWEB)

    Fang, P.; Cen, C.P.; Tang, Z.X.; Zhong, P.Y.; Chen, D.S.; Chen, Z.H. [MEP, Guangzhou (China)

    2011-03-15

    The experiments were performed in a countercurrent packed column in a continuous mode to study the absorption of NOx and SO{sub 2} in urea solutions. On the basis of high SO{sub 2} removal efficiency, the NOx removal efficiencies under various experimental conditions were emphatically measured. The various influencing factors, such as urea concentration, temperature, initial pH value, oxidation degree of nitrogen oxides, SO{sub 2} concentration and additive on removal efficiencies of NOx were studied experimentally, and the optimal conditions were established. The reaction products were analyzed, and reaction mechanism and total chemical reaction equations for simultaneous desulfurization and denitration using urea solution were deduced. Molar reaction enthalpy, molar formation Gibbs function and chemical reaction equilibrium constant were calculated by thermodynamic methods. The calculation results show that the simultaneous desulfurization and denitration are available, and the removal efficiencies are 100% nearly.

  16. Study on Selective Catalytic Reduction Reaction Properties of LaCoO3 Perovskite Catalyst for Diesel NOx Emission Removal%LaCoO3钙钛矿型催化剂对柴油机NOx净化性能研究

    Institute of Scientific and Technical Information of China (English)

    郝斌; 杨铁皂; 吕刚; 宋崇林; 宾峰

    2012-01-01

    LaCoO3 perovskite catalyst was prepared by citric acid complex method and characterized for its physic - chemical properties. Catalytic performance in the SCR of NO, by NH3 was studied and results showed that: pure LaCoO3 granule has a certain ability of catalytic reduction of NOx, especially between 250 to 45℃. However, the undesired catalytic activity for the oxidation of NH3 was too high and could be even largely promoted by a higher temperature. When LaCoO3 was used as SCR catalyst, it showed a certain degree of purification ability of NOx, below 400℃ , but if the temperature was higher than 400℃ , NOx elimination is deteriorated. Moreover, LaCo03 perovskite catalyst was highly capable of enhancing the oxidation of HC and CO regardless of their gas compositions.%采用柠檬酸络合法制备了LaCoO3钙钛矿型催化剂.对其理化特性及NH3-选择性催化还原催化性能的研究结果表明:纯LaCoO3颗粒具有一定的NOx催化还原能力,在250~450℃活性较高;但该催化剂对NH3具有较高的氧化活性,且催化活性随反应温度的升高而提高;在SCR反应中,在400℃以下时,该催化剂显示出一定的NOx净化能力,但当温度超过400℃以后,还原剂的加入反而恶化了NOx排放.不管反应气组成如何,LaCoO3钙钛矿型催化剂对HC和CO都具有良好的催化性能.

  17. Condition in ci engine’s exhaust pipe in light of application nox sensor to determine of catalytic converter efficiency

    OpenAIRE

    Rychter, M.

    2010-01-01

    The development of a catalytic converter required an analysis of selected physical parameters of the supports. This resulted from the necessity to assume given parameters of the supports applied in the tests in exhaust gas environment in the CI engines. An analysis of ionic conductors which constitute the basic solution in voltage sensors providing signals through NOx electrocatalysis. The aim of this paper is to determine the basis for the monitoring of catalytic converters in compression ig...

  18. Role of iron oxide catalysts in selective catalytic reduction of NOx and soot from vehicular emission

    International Nuclear Information System (INIS)

    This study deals with Iron containing catalysts i.e Iron oxide Fe/sub 2/O/sub 3/) Iron potassium oxide Fe/sub 1.9/K/sub 0.1/O/sub 3/, copper iron oxide Cu/sub 0.9/K/sub 0.1/, Fe/sub 2/O/sub 3/, nickel iron oxide Ni Fe/sub 2/O/sub 4/, and Nickel potassium iron oxide Ni/sub 0.95/K/sub 0.05/ Fe/sub 2/O/sub 4/ catalyst were synthesized by using PVA technique. By X-ray Diffraction technique these catalysts were characterized to ensure the formation of crystalline structure. Energy Dispersive X-rays analysis (EDX) was used for the confirmation of presence of different metals and Scanning Electron Microscopy (SEM) for Surface Morphology. Then the catalytic investigations of the prepared catalyst were carried out for their activity measurement toward simultaneous conversion of NOx and Soot from an engine exhaust. Some Iron containing oxide catalysts were partially modified by alkali metal potassium and were used for NOx -Soot reaction in a model exhaust gas. Fe/sub 1.9 K /sub 0.1/O/sub 3/ show high catalytic performance for N/sub 2/ formation in the prepared catalyst. Further studies have shown that Fe/sub 1.9/ K/sub 0.1/ O/sub 3/ was deactivated in a substantial way after about 20 Temperature. Temperature Programmed Reaction (TPR) experiments due to agglomeration of the promoter potassium. Experiments carried out over the aged Fe/sub 1.9/K/sub 0.1/O/sub 3/ catalyst have shown that NOx-soot reaction was suppressed at higher oxygen concentration, since O/sub 2/-soot conversion was kindly favored. More over nitrite species formed at the catalyst surface might play an important role in NOx-soot conversion. (author)

  19. Local Environment and Nature of Cu Active Sites in Zeolite-Based Catalysts for the Selective Catalytic Reduction of NOx

    NARCIS (Netherlands)

    Deka, U.; Lezcano-Gonzalez, I.; Weckhuysen, B.M.; Beale, A.M.

    2013-01-01

    Cu-exchanged zeolites have demonstrated widespread use as catalyst materials in the abatement of NOx, especially from mobile sources. Recent studies focusing on Cu-exchanged zeolites with the CHA structure have demonstrated them to be excellent catalysts in the ammonia-assisted selective catalytic r

  20. Excellent activity and selectivity of Cu-SSZ-13 in the selective catalytic reduction of NOx with NH3

    Energy Technology Data Exchange (ETDEWEB)

    Kwak, Ja Hun; Tonkyn, Russell G.; Kim, Do Heui; Szanyi, Janos; Peden, Charles HF

    2010-10-21

    Superior activity and selectivity of a Cu ion-exchanged SSZ-13 zeolite in the selective catalytic reduction (SCR) of NOx with NH3 were observed, in comparison to Cu-beta and Cu-ZSM-5 zeolites. Cu-SSZ-13 was not only more active in the NOx SCR reaction over the entire temperature range studied (up to 550 °C), but also more selective toward nitrogen formation, resulting in significantly lower amounts of NOx by-products (i.e., NO2 and N2O) than the other two zeolites. In addition, Cu-SSZ-13 demonstrated the highest activity and N2 formation selectivity in the oxidation of NH3. The results of this study strongly suggest that Cu-SSZ-13 is a promising candidate as a catalyst for NOx SCR with great potential in after-treatment systems for either mobile or stationary sources.

  1. Removal of Nox from flue gas with radical oxidation combined with chemical scrubber

    Institute of Scientific and Technical Information of China (English)

    LIN He; GAO Xiang; LUO Zhong-yang; GUAN Shi-pian; CEN Kefa; HUANG Zhen

    2004-01-01

    In this paper, removal of NOx(namely DeNOx) from flue gas by radical injection combined with NaOH solution(26% by weight of NaOH in water) scrubbing was investigated. The experimental results showed that the steady streamer corona occurs through adjusting the flow rate of the oxygen fed into the nozzles electrode. The vapor in the oxygen has influence on the V-I characteristics of corona discharge. Both HNO2 and HNO3 come into being in the plasma reactor and the DeNOx efficiency in the plasma reactor is more than 60%. The overall DeNOx efficiency of the whole system reaches 81.7% when the NaOH solution scrubbing is collaborated.

  2. Selective catalytic reduction (SCR) NOx control for small natural gas-fired prime movers

    International Nuclear Information System (INIS)

    The application of selective catalytic reduction (SCR) to small natural gas-fired prime movers at cogeneration facilities and compressor stations could possibly increase due to regulatory forces to limit NOx from such sources. The natural gas industry is presently without a current database with which to evaluate the cost and operating characteristics of SCR under the conditions anticipated for small prime movers. This paper presents the results from a two-phase study undertaken to document SCR applications with emphasis on SCR system performance and costs. The database of small natural gas-fired prime mover SCR experience, focusing on prime mover characterization, SCR system performance, and SCR system costs will be described. Result from analysis of performance and cost data will be discussed, including analytical tools developed to project SCR system performance and costs

  3. Enhancement of removal of SO2 and NOx by powdery materials in radiation treatment of exhaust gases

    International Nuclear Information System (INIS)

    We studied the effect of powdery silica on radiation removal of SO2 and NOx from mixtures of SO2, NOx, water vapour, oxygen and nitrogen under irradiation by electron beams of 1.5 MeV at 1200C. The SO2 and NOx concentrations decreased when powdery silica was fed without irradiation. Decrements of SO2 and NOx concentrations were markedly enhanced when powdery silica was fed together with the irradiation. The enhancement of SO2- and NOx-removal is attributed to the adsorption of SO2 and NO on the water-covered surface of powdery silica, and the effective removal of NO2 due to the reaction with water adsorbed on the surface of powdery silica. The results obtained show that the addition of powdery silica under irradiation is an effective method of enhancing the removal of SO2 and NOx. (author)

  4. Enhanced Activity of Nanocrystalline Zeolites for Selective Catalytic Reduction of NOx

    International Nuclear Information System (INIS)

    Nanocrystalline zeolites with discrete crystal sizes of less than 100 nm have different properties relative to zeolites with larger crystal sizes. Nanocrystalline zeolites have improved mass transfer properties and very large internal and external surface areas that can be exploited for many different applications. The additional external surface active sites and the improved mass transfer properties of nanocrystalline zeolites offer significant advantages for selective catalytic reduction (SCR) catalysis with ammonia as a reductant in coal-fired power plants relative to current zeolite based SCR catalysts. Nanocrystalline NaY was synthesized with a crystal size of 15-20 nm and was thoroughly characterized using x-ray diffraction, electron paramagnetic resonance spectroscopy, nitrogen adsorption isotherms and Fourier Transform Infrared (FT-IR) spectroscopy. Copper ions were exchanged into nanocrystalline NaY to increase the catalytic activity. The reactions of nitrogen dioxides (NOx) and ammonia (NH3) on nanocrystalline NaY and CuY were investigated using FT-IR spectroscopy. Significant conversion of NO2 was observed at room temperature in the presence of NH3 as monitored by FT-IR spectroscopy. Copper-exchanged nanocrystalline NaY was more active for NO2 reduction with NH3 relative to nanocrystalline NaY

  5. Review of state of the art technologies of selective catalytic reduction of NOx from diesel engine exhaust

    International Nuclear Information System (INIS)

    Increasingly stringent emission legislations, such as US 2010 and Euro VI, for NOx in mobile applications will require the use of intensification of NOx reduction aftertreatment technologies, such as the selective catalytic reduction (SCR). Due to the required higher deNOx efficiency, a lot of efforts have recently been concentrated on the optimization of the SCR systems for broadening the active deNOx temperature window as widely as possible, especially at low temperatures, enhancing the catalysts durability, and reducing the cost of the deNOx system. This paper provides a comprehensive overview of the state-of-the-art SCR technologies, including the alternative ammonia generation from the solid reductants, Vanadium-based, Cu-zeolite (CuZ) and Fe-zeolite (FeZ) based, and the novel chabazite zeolite with small pore size SCR catalysts. Furthermore, the progresses of the highly optimized hybrid approaches, involving combined CuZ and FeZ SCR, passive SCR, integration of DOC + (DPF, SCR), as well as SCR catalyst coated on DPF (referred as SCRF hereinafter) systems are well discussed. Even though SCR technology is considered as the leading NOx aftertreatment technology, attentions have been paid to the adverse by-products, such as NH3 and N2O. Relevant regulations have been established to address the issues. - Highlights: •The review of state of the art technologies of selective catalytic reduction of NOx. •The mainstream V-based, Cu- and Fe-zeolite, and chabazite catalysts are illustrated. •The development of highly optimized hybrid integration SCR systems are analyzed. •The by-products of SCR systems and the corresponding regulations are discussed. •The future perspectives of the advanced SCR technologies are described

  6. Spectroscopic and Kinetic Study of Copper-Exchanged Zeolites for the Selective Catalytic Reduction of NOx with Ammonia

    OpenAIRE

    Bates, Shane Adam

    2013-01-01

    The recent application of metal-exchanged, small-pore zeolites for use in the selective catalytic reduction (SCR) of NOx with ammonia NH3 for automotive deNOx applications has been a great stride in achieving emission standard goals. Copper-exchanged SSZ-13 (Cu-SSZ-13), the small-pore zeolite in this study, has been shown to be very hydrothermally stable and active under conditions presented in the exhaust of the lean-burn diesel engine. In this work, detailed studies were performed to identi...

  7. Effect of manufacturing methods of AgCl/Al2O3 catalyst on selective catalytic reduction of NOx

    Institute of Scientific and Technical Information of China (English)

    Satoshi Kishida; Dong-Ying Ju; Hirofumi Aritani

    2011-01-01

    The AgCl/Al2O3 catalyst has potential for use in the selective catalytic reduction (SCR) of NOx. A compound hydrocarbon, following oxygenation is used as a type of reducing agent. In this experiment, the AgCl/Al2O3 catalyst was produced by four different methods,and the differences among their reduction catalysis of NOx were compared. Ethanol was used as a type of reducing agent. X-ray diffraction analysis was performed to study the crystalline structure and scanning electron microscope and transmission electron microscope (TEM) were applied to determine the microindentation. The results indicated that, in the range of 350-400℃, there was no significant difference on the NOx reduction rate; however, there was dispersion at high and low temperature ranges. The size of the AgCl particles was about 20-100 nm.

  8. Electromagnetic technique for SO2 and NOx removal from coal combustor product gas

    International Nuclear Information System (INIS)

    This paper reports on an advanced SO2 and NOx emission control process that employs high-frequency electromagnetic waves (radio frequency waves or, more specifically, microwaves) which is being developed under the sponsorship of the U.S. Department of Energy's Small business Innovation Research (SBIR) Program. Recently enacted Clean Air Act Amendments will require a significant reduction of SO2 and NOx emissions from coal-fired utility and industrial boilers. Currently, 65 percent of all SO2 emissions in the United States is operated from utility plants. The Cha Corporation, in collaboration with the University of Wyoming, is investigating the electromagnetic technique. The goal of the work is to develop an efficient and cost-effective method for removal of sulfur dioxide (SO2) and nitrogenoxides (NOx) generated from the coal-fired boilers

  9. Selective catalytic reduction system and process for treating NOx emissions using a palladium and rhodium or ruthenium catalyst

    Science.gov (United States)

    Sobolevskiy, Anatoly; Rossin, Joseph A.; Knapke, Michael J.

    2011-07-12

    A process for the catalytic reduction of nitrogen oxides (NOx) in a gas stream (29) in the presence of H.sub.2 is provided. The process comprises contacting the gas stream with a catalyst system (38) comprising zirconia-silica washcoat particles (41), a pre-sulfated zirconia binder (44), and a catalyst combination (40) comprising palladium and at least one of rhodium, ruthenium, or a mixture of ruthenium and rhodium.

  10. NOx removal enhancement by a Jerks - and - Jumps type electrode in a dielectric barrier discharge

    International Nuclear Information System (INIS)

    In this study, the electrode surface of a NOx removal treatment reactor has been modified in order to reduce its electric potential level and, at the same time, to increase its removal capacity by generating a cold plasma using a non-homogenous electric field on the electrode surface. This electric field has been achieved by means of a jerks and jumps-like electrode profile. The other electrode conserves the original flat form. Then, experiments on the removal of NOx were carried out in this 22.4 cm3 reactor. Concentrations of 30-80 μmol/mol of NOx in nitrogen were used with 1 SLPM flows. The exhaust gases were analysed as well as characterised by gas chromatography and mass spectrometry. Additional experiments were also carried out in a second reactor of the same reaction volume but where two conventional flat and parallel electrodes were used, in order to compare the results. The NO removal efficiency in the two flat electrode case approached 87% while ∼98% in the jerks and jumps reactor

  11. Pilot plant for electron beam SO2 and NOx removal from combustion flue gases

    International Nuclear Information System (INIS)

    Polish pilot plant for electron beam flue gas treatment was built in Electro-power Station Kaweczyn. The flue gas flow capacity is equal to 20000 Nm3/h. The applied technology allows simultaneous removal of SO2 and NOx. The process is dry and by product can be used as fertilizer. In the report construction of the pilot plant is described. The preliminary results of investigations proved high efficiency of acidic pollutants removal from flue gases. (author). 23 refs, 6 tabs, 24 ills

  12. Near-Zero Emissions Oxy-Combustion Flue Gas Purification Task 3: SOx/NOx/Hg Removal for Low Sulfur Coal

    Energy Technology Data Exchange (ETDEWEB)

    Zanfir, Monica; Solunke, Rahul; Shah, Minish

    2012-06-01

    The goal of this project was to develop a near-zero emissions flue gas purification technology for existing PC (pulverized coal) power plants that are retrofitted with oxycombustion technology. The objective of Task 3 of this project was to evaluate an alternative method of SOx, NOx and Hg removal from flue gas produced by burning low sulfur coal in oxy-combustion power plants. The goal of the program was to conduct an experimental investigation and to develop a novel process for simultaneously removal of SOx and NOx from power plants that would operate on low sulfur coal without the need for wet-FGD & SCRs. A novel purification process operating at high pressures and ambient temperatures was developed. Activated carbon's catalytic and adsorbent capabilities are used to oxidize the sulfur and nitrous oxides to SO{sub 3} and NO{sub 2} species, which are adsorbed on the activated carbon and removed from the gas phase. Activated carbon is regenerated by water wash followed by drying. The development effort commenced with the screening of commercially available activated carbon materials for their capability to remove SO{sub 2}. A bench-unit operating in batch mode was constructed to conduct an experimental investigation of simultaneous SOx and NOx removal from a simulated oxyfuel flue gas mixture. Optimal operating conditions and the capacity of the activated carbon to remove the contaminants were identified. The process was able to achieve simultaneous SOx and NOx removal in a single step. The removal efficiencies were >99.9% for SOx and >98% for NOx. In the longevity tests performed on a batch unit, the retention capacity could be maintained at high level over 20 cycles. This process was able to effectively remove up to 4000 ppm SOx from the simulated feeds corresponding to oxyfuel flue gas from high sulfur coal plants. A dual bed continuous unit with five times the capacity of the batch unit was constructed to test continuous operation and longevity. Full

  13. Solar efficiency of a photo catalytic nonwoven: dye removal applications

    Energy Technology Data Exchange (ETDEWEB)

    Guillard, C.; Disdier, J.; Herrmann, J. M.; Monnet, C.; Dussaud, J.; Malato, S.; Blanco, J.

    2003-07-01

    A specially designed titania photo catalyst was prepared by coating Ahlstrom non-woven paper, used as a flexible photo catalytic support, with Millennium anatase PC50 and PC500 at different mass coatings. Several types of reactants were treated: formetanate (pesticide), Remazole (azo-dye), Amaranth (azo-dye) and Methylene Blue (model dye). Supported catalysts installed in a new solar photo reactor (STEP) were compared to the well-known CPCs working with slurries (0.5 g/L) of the same catalysts. Efficiency of both photo catalytic system was very similar for formetanate removal but not for dye degradation, for which the CPC was more efficient. Solar UV light adsorption by dyes is proposed as the reason for these results. (Author) 12 refs.

  14. Coke formation over zeolites and CeO2-zeolites and its influence on selective catalytic reduction of NOx

    International Nuclear Information System (INIS)

    Selective catalytic reduction, various possible reasons of coke formation, and temperature programmed oxidation of coke deposits are studied over HFER, HZSM-5 and 15|wt% CeO2-H zeolites. The materials are characterised by TGA, NH3-TPD and in-situ FTIR measurements. HFER based catalysts showed superior NOx (NO+NO2) conversion in SCR with propene compared with HZSM-5 based catalysts. It is found that NO2 (formed by the oxidation of NO) is not the only important intermediate in determining the extent of NOx conversion. The topology and acidity of the zeolites play an important role in selective activation of propene and its reaction with NO2. Over HZSM-5 based catalysts the rate of deposition of carbonaceous compounds is higher than the rate of reaction of activated propene with NO2, leading to unselective reduction to NO. The nature and the amount of the carbonaceous products deposited over the zeolites are found to depend on the acidity, structure of the zeolite and reaction conditions (inert or oxidative atmosphere). Coke deposition rate is enhanced in the presence of oxygen and most of the coke is retained by the zeolite which is detrimental for NOx reduction. in-situ IR studies show that hydrocarbon deposits are more heterogeneous and carbon rich over HZSM-5 compared with HFER. TPO studies show that only a negligible fraction of hydrocarbon deposits are active in NOx conversion

  15. NOx removal using a wet type plasma reactor based on a three-electrode device

    International Nuclear Information System (INIS)

    In this paper, a wet type plasma reactor based on a three electrode device is investigated experimentally in order to remove NO and NOx at low flow rate. First, a comparison of cleaning performances of gas exhaust has been performed when the surface discharge operates in DBD or SD modes. From these previous results, the second part of study has consisted to improve the electrochemical conversion of the wet type plasma reactor by adding a coil between the AC HV power supply and the surface discharge. The parametric study has been performed with 100 ppm of NO content in gas flow at room temperature and atmospheric pressure for a flow rate of 1 L/min. For each electrical parameter tested, an electric characterization and measurement of NOx content via FT-IR has been conducted. The results highlight a better cleaning of gas exhaust when the surface discharge operates in DBD mode. Moreover, the presence of solution promotes the arc transition when the operating mode is SD, resulting a reliability reduction of plasma device. In addition, the measurements show that the insertion of coil in the electrical circuit improves the NOx removal at a given power consumption for the DBD operating mode.

  16. Demonstration of lean NOx catalytic converter technology on a heavy-duty diesel engine. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Heimrich, M.J.

    1996-05-01

    Experimental catalysts for the reduction of oxides of nitrogen (NOx) were evaluated on a 258-horsepower (192 kW) direct-injection heavy-duty diesel engine. An experimental reductant delivery system provided supplementary hydrocarbons for the reduction of NOx. A fuel economy penalty of five percent was measured for initial FTP experiments.

  17. Investigation of Catalytic NOx, reduction with transient techniques, isotopic exchange and FT-IR spectroscopy

    International Nuclear Information System (INIS)

    Emissions from vehicles are suppressed by catalytic conversion, i.e. total oxidation of carbon monoxide and hydrocarbons and reduction of nitrogen oxides. The on-going demand for lower emissions requires more detailed knowledge about the catalytic reaction mechanisms and kinetics on the level of elementary steps, especially because of the mutual interactions in the complex reaction mixture. The reaction mechanisms for the abatement of nitrogen oxides (NOx) are of particular interest, since they are environmentally very unfriendly compounds. Transient experimental techniques can be used as a tool to understand the reaction mechanisms and to develop mathematical models allowing simulation and optimisation of the behaviour of three-way catalyst converters. In chemical kinetics, isotope-labelled reactants are frequently employed to follow reaction pathways and to determine reaction mechanisms. The kinetics and mechanisms of the catalytic reduction of nitrogen oxide (NO) by hydrogen as well as self-decomposition of NO and N2O were studied over alumina based palladium and rhodium-alumina monoliths. In addition, NO reduction with H2 and D2, isotope exchange of hydrogen atoms in water, ammonia and hydrogen with deuterium, as well as adsorption of ammonia and water on the Pd-monolith were studied with transient experiments. Transient step-response experiments, isotopic jumping techniques, steady- state isotopic-transient analysis, temperature programmed desorption (TPD) and Fourier-transformed infrared spectroscopy (FT-IR) were used as experimental techniques. The catalysts were characterised by carbon monoxide chemisorption, nitrogen physisorption and X-ray photoelectron spectroscopy (XPS). Nitrogen, nitrous oxide, ammonia, and water were detected as reaction products in NO reduction by hydrogen. The transient and FT-IR experiments yielded information about the surface reaction mechanisms. The dissociation of NO on the catalyst surface is the crucial step, dominating the

  18. Characterization of LSM/CGO Symmetric Cells Modified by NOx Adsorbents for Electrochemical NOx Removal with Impedance Spectroscopy

    DEFF Research Database (Denmark)

    Shao, Jing; Kammer Hansen, Kent

    2013-01-01

    This study uses electrochemical impedance spectroscopy (EIS) to characterize an LSM/CGO symmetric cell modified by NOx adsorbents for the application of electrochemical NOx reduction. Three cells were prepared and tested: a blank cell, a cell impregnated with BaO, and a cell coated with a Ba......O-Pt-Al2O3 layer. The impedance analysis revealed that modification with the NOx adsorbents, either by impregnating the BaO into the electrode or by adding a BaO-Pt-Al2O3 layer on top of the electrode significantly enhanced the electrode activity. This activity enhancement was mainly due to the decrease...

  19. Alternative catalysts and technologies for NOx removal from biomass- and wastefired plants

    DEFF Research Database (Denmark)

    Schill, Leonhard

    poisoning problem: Use of Ag/Al2O3 as catalyt with hydrocarbons (ethanol, propene) as reductants (HCSCR), and by developing low-temperature catalysts for NH3-SCR to be used in the tail-end position at 150 C, making costly reheating redundant. The hope that HC-SCR is insensitive to potassium has been in vain....... The deNOx activity over Ag/Al2O3 used in ethanol-SCR is practically as much reduced as in the NH3-SCR case over the traditional VWT catalyst. Furthermore, poisoning with potassium leads to unselective oxidation of the hydrocarbons instead of NO reduction and SO2 concentrations as low as 20 ppm can...

  20. Kinetic Study of Co-β-Zeolite for Selective Catalytic Reduction of NOx with Propane

    Institute of Scientific and Technical Information of China (English)

    毛树红; 王润平; 池永庆; 王艳; 张清华; 丛燕青

    2011-01-01

    The effects of grain size, space velocity, temperature and reactant concentration on the kinetics of NOx reduction with propane over Co-β-zeolite catalyst were investigated. The external mass transfer phenomenon was examined by varying the space velocity. The results show that the transfer can be negligible when the space velocity is greater than 60000 h-1 in low temperature range. However, the transfer exists at high temperatures even when the space velocity reaches a high level.Variation of the catalyst grain size from 0.05 to 0.125 mm does not change the conversion rate of NOx. The concentrations of components, NOx, C3H8 and O2, were also investigated to have a better understanding of mechanism. Based on the experimental data, the selectivity formula was proposed. The results shows that lower temperature is helpful to get higher selectivity as the activation energy of hydrocarbon oxidation, Ea,2, is greater than that of NOx reduction, Ea,1, (Ea,2>Ea,l). High NOx concentration and low C3H8 concentration are beneficial to high selectivity. However in order to maintain high activity simultaneously, the temperature and C3H8 concentration should be high enough to promote NOx reduction. 10%(φ) H2O and 75×i0-6(φ) SO2 were introduced into the reaction system, and Co-β-zeolite shows strong resistance to water and SO2.

  1. NOx removal from vehicle emissions by functionality surface of asphalt road

    International Nuclear Information System (INIS)

    This paper reported the potential of heterogeneous photocatalysis as an advanced oxidation technology for NOx removal from vehicle emissions by using TiO2 as a photocatalyst immobilized on the surface of asphalt road. Based on asphalt road material porous characteristic, we utilized permeability technology to make asphalt nano-TiO2 to be environmental protection materials. And then using scanning electron microscope, we observed the penetrating effect of TiO2. The effect of surface friction, humidity and light intensity on NOx removal had been systematically investigated by the use of TiO2 immobilized on the surface of asphalt road as photocatalytic environmental protection materials. In addition, the decontaminating effect was tested by contrast test in TiO2 spraying section with non-spraying section, while the productions were used in road environment. Results of experiment revealed that decontaminating rate of the productions ranged from 6% to 12% this kind of photochemical catalysis environmental protection material has good environment purification function.

  2. Enhanced catalytic activity over MIL-100(Fe) loaded ceria catalysts for the selective catalytic reduction of NOx with NH₃ at low temperature.

    Science.gov (United States)

    Wang, Peng; Sun, Hong; Quan, Xie; Chen, Shuo

    2016-01-15

    The development of catalysts for selective catalytic reduction (SCR) reactions that are highly active at low temperatures and show good resistance to SO2 and H2O is still a challenge. In this study, we have designed and developed a high-performance SCR catalyst based on nano-sized ceria encapsulated inside the pores of MIL-100(Fe) that combines excellent catalytic power with a metal organic framework architecture synthesized by the impregnation method (IM). Transmission electron microscopy (TEM) revealed the encapsulation of ceria in the cavities of MIL-100(Fe). The prepared IM-CeO2/MIL-100(Fe) catalyst shows improved catalytic activity both at low temperatures and throughout a wide temperature window. The temperature window for 90% NOx conversion ranges from 196 to 300°C. X-ray photoelectron spectroscopy (XPS) and in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFT) analysis indicated that the nano-sized ceria encapsulated inside MIL-100(Fe) promotes the production of chemisorbed oxygen on the catalyst surface, which greatly enhances the formation of the NO2 species responsible for fast SCR reactions. PMID:26414927

  3. Study on the removal of NOx from simulated flue gas using acidic NaClO2 solution

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The study on the removal of NOx from simulated flue gas has been carried out in lab-scale bubbling reactor using acidic solutions of sodium chlorite. Experiments were performed at various pH values and inlet NO concentrations in absence as well as presence of SO2 gas at 45oC. The effect of SO2 on NO oxidation and NO2 absorption was critically examined. The oxidative ability of sodium chlorite was investigated at different pH values and it was found to be a better oxidant at a pH less than 4. In acidic medium, sodium chlorite decomposed into ClO2 gas, which is believed to participate in NO oxidation as well as in NO2 absorption. A plausible NOx removal mechanism using acidic sodium chlorite solution has been postulated. A maximum NOx removal efficiency of about 81% has been achieved.

  4. Innovative clean coal technology (ICCT): demonstration of selective catalytic reduction (SCR) technology for the control of nitrogen oxide (NOx) emission from high-sulfur, coal-fired boilers - economic evaluation of commercial-scale SCR applications for utility boilers

    International Nuclear Information System (INIS)

    This report presents the results of an economic evaluation produced as part of the Innovative Clean Coal Technology project, which demonstrated selective catalytic reduction (SCR) technology for reduction of NOx emissions from utility boilers burning U.S. high-sulfur coal. The document includes a commercial-scale capital and O ampersand M cost evaluation of SCR technology applied to a new facility, coal-fired boiler utilizing high-sulfur U.S. coal. The base case presented herein determines the total capital requirement, fixed and variable operating costs, and levelized costs for a new 250-MW pulverized coal utility boiler operating with a 60-percent NOx removal. Sensitivity evaluations are included to demonstrate the variation in cost due to changes in process variables and assumptions. This report also presents the results of a study completed by SCS to determine the cost and technical feasibility of retrofitting SCR technology to selected coal-fired generating units within the Southern electric system

  5. The acclimation of Chlorella to high-level nitrite for potential application in biological NOx removal from industrial flue gases.

    Science.gov (United States)

    Li, Tianpei; Xu, Gang; Rong, Junfeng; Chen, Hui; He, Chenliu; Giordano, Mario; Wang, Qiang

    2016-05-20

    Nitrogen oxides (NOx) are the components of fossil flue gas that give rise to the greatest environmental concerns. This study evaluated the ability of the green algae Chlorella to acclimate to high level of NOx and the potential utilization of Chlorella strains in biological NOx removal (DeNOx) from industrial flue gases. Fifteen Chlorella strains were subject to high-level of nitrite (HN, 176.5 mmolL(-1) nitrite) to simulate exposure to high NOx. These strains were subsequently divided into four groups with respect to their ability to tolerate nitrite (excellent, good, fair, and poor). One strain from each group was selected to evaluate their photosynthetic response to HN condition, and the nitrite adaptability of the four Chlorella strains were further identified by using chlorophyll fluorescence. The outcome of our experiments shows that, although high concentrations of nitrite overall negatively affect growth and photosynthesis of Chlorella strains, the degree of nitrite tolerance is a strain-specific feature. Some Chlorella strains have an appreciably higher ability to acclimate to high-level of nitrite. Acclimation is achieved through a three-step process of restrict, acclimate, and thriving. Notably, Chlorella sp. C2 was found to have a high tolerance and to rapidly acclimate to high concentrations of nitrite; it is therefore a promising candidate for microalgae-based biological NOx removal. PMID:27010349

  6. Coupling catalytic hydrolysis and oxidation for CS2 removal

    Institute of Scientific and Technical Information of China (English)

    WANG Li; WU Diyong; WANG Shudong; YUAN Quan

    2008-01-01

    CS2 removal was Obtained by coupling catalytic hyidation on bi-functional catalyst.On the hydrolysis active sites,CS2 is hydrolyzed to H2S,while on the oxidation active sites,H2S is oxidized to elemental S or sulfuric acid deposited on the porous support.The above process can be expressed as follows:CS2→H2O COS →H2O H2S→O2 S/SO2- 4.H2S oxidation eliminates its prohibition on CS2 hydrolysis so that the rate of coupling removal CS2 is 5 times higher than that of CS2 hydrolysis.The same active energy of hydrolysis and coupling reaction also indicates that H2S oxidation does not change the reaction mechanism of CS2 hydrolysis.Temperature has obvious effect on the process while the mole ratio of O2 concentration to CS2 concentration (O/S) does not,especially in excess of 2.5.The formation of sulfuric acid on the catalyst surface poisons hydrolysis active sites and causes the decrease of left OH-1 concentration on the catalysts surface.Lower temperature is suggested for this bi-functional catalyst owing to the low yield ratio of S/SO4 2-.

  7. Zeolite catalysts and their use in selective catalytic reduction of NOx

    NARCIS (Netherlands)

    Seijger, G.B.F.; Van den Bleek, C.M.; Calis, H.P.A.

    2003-01-01

    The invention is directed to catalyst compositions comprising a zeolite, as well as to processes for the reduction of nitrogen oxides (NOx) employing these catalyst compositions. The catalyst compositions of the invention comprise a zeolite of the ferrierite type (FER), which zeolite is ion exchange

  8. Removal of platinum group metals from the used auto catalytic converter

    Directory of Open Access Journals (Sweden)

    A. Fornalczyk

    2009-04-01

    Full Text Available Recycling of platinum group metals from the used auto catalytic converters is profitable from ecological and also economical point of view. This work presents the analysis of the chances of removing the platinum group metals (PGM from the used auto catalytic converters applying pyrometallurgical and hydrometallurgical methods. The characteristics of auto catalytic converter is shown as well the available technologies used for processing the auto catalytic converters are also presented.

  9. Removal of platinum group metals from the used auto catalytic converter

    OpenAIRE

    A. Fornalczyk; M. Saternus

    2009-01-01

    Recycling of platinum group metals from the used auto catalytic converters is profitable from ecological and also economical point of view. This work presents the analysis of the chances of removing the platinum group metals (PGM) from the used auto catalytic converters applying pyrometallurgical and hydrometallurgical methods. The characteristics of auto catalytic converter is shown as well the available technologies used for processing the auto catalytic converters are also presented.

  10. Potential application of aerobic denitrifying bacterium Pseudomonas aeruginosa PCN-2 in nitrogen oxides (NOx) removal from flue gas.

    Science.gov (United States)

    Zheng, Maosheng; Li, Can; Liu, Shufeng; Gui, Mengyao; Ni, Jinren

    2016-11-15

    Conventional biological removal of nitrogen oxides (NOx) from flue gas has been severely restricted by the presence of oxygen. This paper presents an efficient alternative for NOx removal at varying oxygen levels using the newly isolated bacterial strain Pseudomonas aeruginosa PCN-2 which was capable of aerobic and anoxic denitrification. Interestingly, nitric oxide (NO), as the obligatory intermediate, was negligibly accumulated during nitrate and nitrite reduction. Moreover, normal nitrate reduction with decreasing NO accumulation was realized under O2 concentration ranging from 0 to 100%. Reverse transcription and real-time quantitative polymerase chain reaction (RT-qPCR) analysis revealed that high efficient NO removal was attributed to the coordinate regulation of gene expressions including napA (for periplasmic nitrate reductase), nirS (for cytochrome cd1 nitrite reductase) and cnorB (for NO reductase). Further batch experiments demonstrated the immobilized strain PCN-2 possessed high capability of removing NO and nitrogen dioxide (NO2) at O2 concentration of 0-10%. A biotrickling filter established with present strain achieved high NOx removal efficiencies of 91.94-96.74% at inlet NO concentration of 100-500ppm and O2 concentration of 0-10%, which implied promising potential applications in purifying NOx contaminated flue gas.

  11. Potential application of aerobic denitrifying bacterium Pseudomonas aeruginosa PCN-2 in nitrogen oxides (NOx) removal from flue gas.

    Science.gov (United States)

    Zheng, Maosheng; Li, Can; Liu, Shufeng; Gui, Mengyao; Ni, Jinren

    2016-11-15

    Conventional biological removal of nitrogen oxides (NOx) from flue gas has been severely restricted by the presence of oxygen. This paper presents an efficient alternative for NOx removal at varying oxygen levels using the newly isolated bacterial strain Pseudomonas aeruginosa PCN-2 which was capable of aerobic and anoxic denitrification. Interestingly, nitric oxide (NO), as the obligatory intermediate, was negligibly accumulated during nitrate and nitrite reduction. Moreover, normal nitrate reduction with decreasing NO accumulation was realized under O2 concentration ranging from 0 to 100%. Reverse transcription and real-time quantitative polymerase chain reaction (RT-qPCR) analysis revealed that high efficient NO removal was attributed to the coordinate regulation of gene expressions including napA (for periplasmic nitrate reductase), nirS (for cytochrome cd1 nitrite reductase) and cnorB (for NO reductase). Further batch experiments demonstrated the immobilized strain PCN-2 possessed high capability of removing NO and nitrogen dioxide (NO2) at O2 concentration of 0-10%. A biotrickling filter established with present strain achieved high NOx removal efficiencies of 91.94-96.74% at inlet NO concentration of 100-500ppm and O2 concentration of 0-10%, which implied promising potential applications in purifying NOx contaminated flue gas. PMID:27469045

  12. Electrochemical Removal of NOx-Gasses by Use of LSM-Cathodes Impregnated with a NOx Storage Compound

    DEFF Research Database (Denmark)

    Traulsen, Marie Lund; Kammer Hansen, Kent

    2010-01-01

    Electrochemical decomposition of NO on La0.85Sr0.15MnO3-- Ce0.90Gd0.10O1.95electrodes with and without KNO3 impregnation is investigated. The KNO3 is added as this compound is expected to work as a NOx-storage compound. Measurements are made in the temperature range 300-400 degree C and in three...

  13. NOx/SO2 removal with no waste - the SNOX process

    International Nuclear Information System (INIS)

    A no waste, NOx/SO2 removal technology entitled SNOX is currently being demonstrated in Niles, Ohio at the Ohio Edison Niles Generating Plant. This project is part of the second round of the Department of Energy Clean Coal Technology Program. The demonstration project will treat a 35 MWe slipstream from a 108 MWe boiler burning 3.2% sulfur Ohio coal. The objectives of this four-year project are to demonstrate the SNOX technology using high sulfur coal, quality and quantify the consumables and products of the process, and verify the operating and maintenance costs. This paper describes the SNOX Process and the Niles Demonstration Project. Initial results from the eighteen month testing program and a discussion of the market potential of the SNOX Process are also presented. 3 refs., 3 tabs

  14. Experimental Study of Selective Catalytic Reduction System On CI Engine Fuelled with Diesel-Ethanol Blend for NOx Reduction with Injection of Urea Solutions

    Directory of Open Access Journals (Sweden)

    R. Praveen

    2014-05-01

    Full Text Available Nowadays exhaust emission control from internal combustion engines have become one of the most important challenges. Oxides of nitrogen (NOx are one of the major hazardous pollutants that come out from diesel engines. There are various techniques existing for NOx control but each techniques has its own advantages and disadvantages. Technologies available for NOx reductions either increase other polluting gas emission or increase fuel consumption. The objective of this paper is to determine the maximum reduction of NOx emissions by varying concentration of urea solution with reduction catalyst. An aqueous solution of urea was injected in engine exhaust pipe for reducing NOx emissions in single cylinder light duty stationery DI diesel engine fuelled with diesel and diesel- (10% ethanol blend. A concentration of urea solution varying from 30 to 35% by weight with constant flow rates and tested with fitting Titanium dioxide (TiO2 coated catalyst which controls by products of ammonia and water vapour. Results indicated that a maximum of 70 % of NOx reduction was achieved an engine fuelled with diesel-ethanol blend and constant flow rate of 0.75 lit/hr with an urea concentration of 35% and 66% NOx of reduced with neat diesel using Titanium dioxide catalyst in Selective Catalytic Reduction system.

  15. Mechanism of propene poisoning on Fe-ZSM-5 for selective catalytic reduction of NO(x) with ammonia.

    Science.gov (United States)

    Li, Junhua; Zhu, Ronghai; Cheng, Yisun; Lambert, Christine K; Yang, Ralph T

    2010-03-01

    Application of Fe-zeolites for urea-SCR of NO(x) in diesel engine is limited by catalyst deactivation with hydrocarbons. In this work, we investigated the effect of propene on the activity of Fe-ZSM-5 for selective catalytic reduction of NO(x) with ammonia (NH(3)-SCR), and proposed a deactivation mechanism of Fe(3+) active site blockage by propene residue. The NO conversion decreased in the presence of propene at various temperatures, while the effect was not significant when NO was replaced by NO(2) in the feed, especially at low temperatures (<300 degrees C). The surface area and pore volume were decreased due to carbonaceous deposition. The site blockage was mainly on Fe(3+) sites on which NO was to be oxidized to NO(2). The activity for NO oxidation to NO(2) was significantly inhibited on a propene poisoned catalyst below 400 degrees C. The adsorption of NH(3) on the Bronsted acid sites to form NH(4)(+) was not hindered even on the propene poisoned catalyst, and the amount of absorbed NH(3) was still abundant and enough to react with NO(2) to generate N(2). The hydrocarbon oxygenates such as formate, acetate, and containing nitrogen organic compounds were observed on catalyst surface, however, no graphitic carbonaceous deposit was formed. PMID:20136123

  16. Effect of process parameters and injector position on the efficiency of NOx reduction by selective non catalytic reduction technique

    International Nuclear Information System (INIS)

    An experimental investigation has been performed to study the effect of atomizer pressure dilution of the reducing reagent and the injector position on the efficiency or the NOx reduction by a selective non-catalytic reduction technique using urea as a reducing agent. Experiments were performed with a flow reactor in which flue gas was generated by the combustion of methane in air at stoichiometric amount of oxygen and the desired levels of initial NOx (400-450 ppm) were achieved by doping the flame with ammonia. The work was directed to investigate the effect of atomizer pressure, dilution of urea reagent and the injector position. The atomizer pressure was varied from 1 to 3bar and 20-25% increase in efficiency was observed by decreasing the pressure. Effect of dilution of urea solution was investigated by varying the strength of the solution from the 8 to 32% and 40-45% increase in the efficiency was observed. Effects of injector position was investigated by injecting the urea solution both in co current and counter current direction of the flue gases and 20-25% increase in the efficiency was observed in counter current direction. (author)

  17. Development of the Aqueous Processes for Removing NOx from Flue Gases.

    Science.gov (United States)

    Chappell, Gilford A.

    A screening study was conducted to evaluate the capability of aqueous solutions to scrub NOx from the flue gases emitted by stationary power plants fired with fossil fuels. The report summarizes the findings of this laboratory program. The experimental program studied the following media for absorption of NOx from flue gases containing no NOx:…

  18. Mesoporous titania-alumina mixed oxide: A preliminary study on synthesis and application in selective catalytic reduction of NOx

    International Nuclear Information System (INIS)

    Titania-alumina mixed oxide was synthesized hydrothermally using tetrapropylammonium hydroxide (TPAOH) as the template. The dried, calcined and palladium loaded samples were characterized for particle morphology, weight loss, nitrogen adsorption/desorption at liquid nitrogen temperature, texture and metal dispersion. The Pd loaded material was tested for NO reduction in a fixed bed catalytic reactor using a simulated gas mixture closely resembling lean burn engine exhaust. Scanning electron microscopy of the dried and calcined samples revealed a well developed tubular fibrous network of titania-alumina. Thermogravimetry (TG) of the dried sample indicated about 16% weight loss due to decomposition of an oxy-hydroxide structure of the material, mostly boehmite, which was confirmed by X-ray diffraction (XRD) measurements. The boehmite phase changed to poorly crystalline γ-alumina upon calcination where as titania remained as anatase. BET specific surface area, adsorption-desorption isotherms and BJH pore size distributions indicated formation of a mesoporous structure. The surface area of the dried material increased when calcined at 600 deg. C but the pore size distribution patterns for the dried, calcined and palladium dispersed materials remained unchanged. These observations along with TG and XRD analyses suggest that a thermo-resistant, mesoporous, high surface area, crystalline titania-alumina framework can be prepared using the hydrothermal synthesis route. A peak NOx conversion of 75% with the palladium dispersed catalyst indicates high catalytic activity, possibly due to high dispersion of Pd confirmed by CO chemisorption studies

  19. Multi-stage selective catalytic reduction of NOx in lean burn engine exhaust

    Energy Technology Data Exchange (ETDEWEB)

    Penetrante, B.M.; Hsaio, M.C.; Merritt, B.T.; Vogtlin, G.E. [Lawrence Livermore National Lab., CA (United States)

    1997-12-31

    Many studies suggest that the conversion of NO to NO{sub 2} is an important intermediate step in the selective catalytic reduction (SCR) of NO{sub x} to N{sub 2}. Some effort has been devoted to separating the oxidative and reductive functions of the catalyst in a multi-stage system. This method works fine for systems that require hydrocarbon addition. The hydrocarbon has to be injected between the NO oxidation catalyst and the NO{sub 2} reduction catalyst; otherwise, the first-stage oxidation catalyst will also oxidize the hydrocarbon and decrease its effectiveness as a reductant. The multi-stage catalytic scheme is appropriate for diesel engine exhausts since they contain insufficient hydrocarbons for SCR, and the hydrocarbons can be added at the desired location. For lean-burn gasoline engine exhausts, the hydrocarbons already present in the exhausts will make it necessary to find an oxidation catalyst that can oxidize NO to NO{sub 2} but not oxidize the hydrocarbon. A plasma can also be used to oxidize NO to NO{sub 2}. Plasma oxidation has several advantages over catalytic oxidation. Plasma-assisted catalysis can work well for both diesel engine and lean-burn gasoline engine exhausts. This is because the plasma can oxidize NO in the presence of hydrocarbons without degrading the effectiveness of the hydrocarbon as a reductant for SCR. In the plasma, the hydrocarbon enhances the oxidation of NO, minimizes the electrical energy requirement, and prevents the oxidation of SO{sub 2}. This paper discusses the use of multi-stage systems for selective catalytic reduction of NO{sub x}. The multi-stage catalytic scheme is compared to the plasma-assisted catalytic scheme.

  20. Widening Synthesis Bottlenecks: Realization of Ultrafast and Continuous-Flow Synthesis of High-Silica Zeolite SSZ-13 for NOx Removal.

    Science.gov (United States)

    Liu, Zhendong; Wakihara, Toru; Oshima, Kazunori; Nishioka, Daisuke; Hotta, Yuusuke; Elangovan, Shanmugam P; Yanaba, Yutaka; Yoshikawa, Takeshi; Chaikittisilp, Watcharop; Matsuo, Takeshi; Takewaki, Takahiko; Okubo, Tatsuya

    2015-05-01

    Characteristics of zeolite formation, such as being kinetically slow and thermodynamically metastable, are the main bottlenecks that obstruct a fast zeolite synthesis. We present an ultrafast route, the first of its kind, to synthesize high-silica zeolite SSZ-13 in 10 min, instead of the several days usually required. Fast heating in a tubular reactor helps avoid thermal lag, and the synergistic effect of addition of a SSZ-13 seed, choice of the proper aluminum source, and employment of high temperature prompted the crystallization. Thanks to the ultra-short period of synthesis, we established a continuous-flow preparation of SSZ-13. The fast-synthesized SSZ-13, after copper-ion exchange, exhibits outstanding performance in the ammonia selective catalytic reduction (NH3 -SCR) of nitrogen oxides (NOx ), showing it to be a superior catalyst for NOx removal. Our results indicate that the formation of high-silica zeolites can be extremely fast if bottlenecks are effectively widened. PMID:25801140

  1. Evaluation of the characteristics for CO removal efficiencies and NOx generation in the post combustion chamber of vitrification plant

    International Nuclear Information System (INIS)

    A Post Combustion Chamber (PCC) is installed for the treatment of unburned hazardous material generated from a Cold Crusible Melter(CCM). Characteristics of CO removal and NOx generation inside the PCC was evaluated. CO removal efficiencies were measured at the temperature of 850 .deg. C and 1,100 .deg. C. In the both cases, the efficiencies above 99.5%, which are high enough to meet the exhaust regulations in the studied process, were obtained. Thermal NOx amount in the outlet of PCC was analyzed during the various PCC operation modes, such as the build-up mode, the stand-by mode, and the steady state with or without feeding. The results showed that the thermal NOx generation was affected by excess O2 amount rather than temperature and residence time of off-gas in the PCC during the steady state. However, the residence time and local non-uniform mixing of gases inside the PCC were dominant parameters in the NOx generation during the transient (bulid-up) mode

  2. Diesel emission control: Catalytic filters for particulate removal

    Directory of Open Access Journals (Sweden)

    Debora Fino

    2007-01-01

    Full Text Available The European diesel engine industry represents a vital sector across the Continent, with more than 2 million direct work positions and a turnover of over 400 billion Euro. Diesel engines provide large paybacks to society since they are extensively used to transport goods, services and people. In recent years increasing attention has been paid to the emissions from diesel engines which, like gasoline engine emissions, include carbon monoxide (CO, hydrocarbons (HC and oxides of nitrogen (NOx. Diesel engines also produce significant levels of particulate matter (PM, which consists mostly of carbonaceous soot and a soluble organic fraction (SOF of hydrocarbons that have condensed on the soot.

  3. Catalytic pleat filter bags for combined particulate separation and nitrogen oxides removal from flue gas streams

    International Nuclear Information System (INIS)

    The development of a high temperature catalytically active pleated filter bag with hybrid filter equipment for the combined removal of particles and nitrogen oxides from flue gas streams is presented. A special catalyst load in stainless steel mesh cartridge with a high temperature pleated filter bag followed by optimized catalytic activation was developed to reach the required nitrogen oxides levels and to maintain the higher collection efficiencies. The catalytic properties of the developed high temperature filter bags with hybrid filter equipment were studied and demonstrated in a pilot scale test rig and a demonstration plant using commercial scale of high temperature catalytic pleated filter bags. The performance of the catalytic pleated filter bags were tested under different operating conditions, such as filtration velocity and operating temperature. Moreover, the cleaning efficiency and residual pressure drop of the catalyst loaded cartridges in pleated filter bags were tested. As result of theses studies, the optimum operating conditions for the catalytic pleated filter bags are determined. (author)

  4. Removal of dissolved oxygen from water using a Pd-resin based catalytic reactor

    Institute of Scientific and Technical Information of China (English)

    Wenxin SHI; Chongwei CUI; Liye ZHAO; Shuili YU; Xia YUN

    2009-01-01

    The removal of dissolved oxygen (DO) from water was studied experimentally in a Pd-resin base catalyst reactor using purified hydrogen gas as a reducing agent. The effects of various operating conditions, such as hydrogen and water flow rates, height of the catalytic resin bed, temperature, pH value and nan time, on the removal of DO, had been studied extensively. The results shows that DO could be removed by the reactor from ppm to ppb levels at ambient temperature. Increases of temperature, H2gas rate and the height of the catalytic resin were helpful to improve the DO removal rate. The change of pH value fom 4 to 12 resulted in no effect on DO removal. Reaction time was the key factor to control the DO removal efficiency. Only when the reaction time was longer than 2.3 minutes under the experimental conditions, could a very low DO level be achieved.

  5. DEVELOPMENT OF HIGH ACTIVITY, COAL-DERIVED, PROMOTED CATALYTIC SYSTEMS FOR NOx REDUCTION AT LOW TEMPERATURES

    Energy Technology Data Exchange (ETDEWEB)

    Joseph M. Calo

    2000-07-21

    This project is directed at an investigation of catalytic NO{sub x} reduction mechanisms on coal-derived, activated carbon supports at low temperatures. Promoted carbon systems offer some potentially significant advantages for heterogeneous NO{sub x} reduction. These include: low cost; high activity at low temperatures, which minimizes carbon loss; oxygen resistance; and a support material which can be engineered with respect to porosity, transport and catalyst dispersion characteristics. During the reporting period, the following has been accomplished: (1) Steady-state reactivity studies in the packed bed reactor were extended to the NO/CO-carbon reaction system as a function of temperature and NO and CO concentrations. It was found that the NO reaction rate increased in the presence of CO, and the apparent activation energy decreased to about 75 {+-} 8 kJ/mol. In addition, the influence of mass transfer limitations were noted at low NO and CO concentrations. (2) The packed bed reactor/gas flow system has been applied to performing post-reaction temperature programmed desorption (TPD) studies of intermediate surface complexes following steady-state reaction. It was found that the amount of CO-evolving intermediate surface complexes exceeded that of the N{sub 2}-evolving surface complexes, and that both increased with reaction temperature. The TPD spectra indicates that both types of complexes desorb late, suggesting that they have high desorption activation energies. Plans for the next reporting period include extending the temperature programmed desorption studies in the packed bed reactor system to the NO/CO reaction system, including exposure to just CO, as well as NO/CO mixtures.

  6. Pulsed sub-microsecond dielectric barrier discharge treatment of simulated glass manufacturing industry flue gas: removal of SO2 and NOx

    International Nuclear Information System (INIS)

    Experiments were carried out to investigate the removal of SO2 and NOx from simulated glass manufacturing industry flue gas containing O2, N2, NO, NO2, CO2, SO2 and H2O using a sub-microsecond pulsed dielectric barrier discharge (DBD) at atmospheric pressure. Removal efficiencies of SO2 and NOx (NO+NO2) were achieved as a function of gas temperature for two specific energies and two initial NO, NO2 and SO2 concentrations. The higher SO2 and NOx removal efficiencies were achieved in a gas stream containing 163 ppm of SO2, 523 ppm of NO, 49 ppm of NO2, 14% of CO2, 8% of O2, 16% of H2O and N2 as balance. The experimental results were evaluated using the energy cost or W-value (eV/molecule removed). About 100% of SO2 and 36% of NOx were removed at a gas temperature of 100 deg. C with an energy cost of about 45 eV/molecule removed and 36 eV/molecule removed, respectively. These results indicate that DBD plasmas have the potential to remove SO2 and NOx from gas streams without additives

  7. DEVELOPMENT OF HIGH ACTIVITY, COAL-DERIVED, PROMOTED CATALYTIC SYSTEMS FOR NOx REDUCTION AT LOW TEMPERATURES

    Energy Technology Data Exchange (ETDEWEB)

    Joseph M. Calo

    2000-07-24

    This project is directed at an investigation of catalytic NO{sub x} reduction mechanisms on coal-derived, activated carbon supports at low temperatures. Promoted carbon systems offer some potentially significant advantages for heterogeneous NO{sub x} reduction. These include: low cost; high activity at low temperatures, which minimizes carbon loss; oxygen resistance; and a support material which can be engineered with respect to porosity, transport and catalyst dispersion characteristics. During the reporting period, TPD studies were conducted following steady-state reaction in NO/CO mixtures in helium. From these studies, the following points have been concluded: (1) The total amount of CO and N{sub 2} evolved following reaction in NO increases with reaction temperature. The TPD spectra are skewed to high temperatures, indicating more stable surface complexes with high desorption activation energies. (2) The total amount of CO evolved following exposure of the char sample to CO at reaction temperatures decreases with reaction temperature, similar to chemisorption behavior. The CO TPD spectra are shifted to lower temperatures, indicating more labile oxygen surface complexes with lower desorption activation energies. (3) The total amount of CO evolved following reaction in NO/CO mixtures decreases with reaction temperature, while the evolved N{sub 2} still increases with reaction temperature. The CO TPD spectra appear more similar to those obtained following exposure to pure CO, while the N{sub 2} TPD spectra are more similar to those obtained followed reaction in just CO. Based on the preceding observations, a simple mechanism was formulated whereby two different types of surface complexes are formed by NO and CO; the former are more stable, and the latter more labile. This produces two parallel routes for the NO-carbon reaction: (a) the C(O) complexes formed directly by NO desorb as CO; and (b) The C(CO) complexes formed by CO, react with NO to produce CO{sub 2

  8. Research advance on the catalysts for simultaneous removal of soot and NOx%同时去除碳烟颗粒物和氮氧化物催化剂研究进展

    Institute of Scientific and Technical Information of China (English)

    朱昌权; 梁红; 李树华; 洪燕霞

    2011-01-01

    The latest research progress in catalytic performance of noble metal catalyst, single metal oxides and mixed metal oxides for simultaneous catalytic removal of NOx and soot from exhaust gases of diesel engines was reviewed. The major existing problems and research direction in the field of catalysis were outlined.%针对柴油车尾气排放的两大主要污染物碳烟颗粒物和氮氧化物的同时催化去除,综述了贵金属催化剂、单一金属氧化物和复合金属氧化物催化剂的研究进展,并提出了该催化研究领域存在的主要问题及发展方向.

  9. Removal of Xylene fromWaste Air Stream Using Catalytic Ozonation Process

    Directory of Open Access Journals (Sweden)

    H Mokarami

    2010-10-01

    Full Text Available "n "n "nBackgrounds and Objectives: Volatile organic compounds (VOCs are one of the common groups of contaminants encountered in the industrial activities, emitted through air stream into the atmosphere. To prevent the human and environmental health from the adverse effects of VOCs, air streams containing VOCs need to be treated before discharging to environment. This study was aimed at investigating the catalytic ozonation process for removing xylene from a contaminated air stream."nMaterials and Methods: In the present work, a bench scale experimental setup was constructed and used for catalytic ozonation of xylene. The performance of catalytic ozonation process was compared with that of single adsorption and ozonation in removal of several concentration of xylene under the similar experimental conditions."nResults: The results indicated that the efficiency of catalytic ozonation was higher than that of single adsorption and ozonation in removal of xylene. The emerging time and elimination capacity of xylene for inlet concentration of 300 ppm was 1.4 and 5.8 times of those in adsorption system. The activated carbon acted as catalyst in the presence of ozone and thus attaining the synergistic effect for xylene degradation."nConclusion: catalytic ozonation process is an efficient technique the treatment of air streams containing high concentrations of xylene. The adsorption systems can also be simply retrofitted to catalytic ozonation process and thereby improving their performance for treating VOCs.

  10. Simultanous removal of VOCs and Nox by oxides of Mg, Cu, Al, and Fe, derivatives of hydrotalicites compounds

    International Nuclear Information System (INIS)

    A series of Mg(Cu)-AlFe mixed oxides derived from Hydrotalcites-Like compounds has been prepared. These solids were characterized by various physico-chemical methods and their catalytic performances were tested towards the catalytic oxidation of propene and the simultaneous elimination of propene and NOx. X-Ray Diffraction of the calcined samples, revealed the existence of oxide and spinel phases such as MgO, CuO,-Fe2O3 and/or Fe3O4, MgFe2O4or CuFe2O4. Moreover, the temperature programmed reduction showed that copper and iron oxide species are easily reducible. The catalytic performances of the catalysts towards propene oxidation showed a better activity for Cu2Mg2Fe2500 due to a better dispersion of copper species in this solid. On the other hand, samples with low copper and iron contents presented a better activity towards the simultaneous elimination of propene and NO. (author)

  11. Technology for the Catalytic Removal of Nitrogen Oxides in the Lean-Burn Exhaust of Vehicles%稀燃汽车尾气中氮氧化物的催化消除技术

    Institute of Scientific and Technical Information of China (English)

    潘广宏; 孟明

    2011-01-01

    Lean-burn technology can not only improve fuel economic efficiency but also reduce CO2 emission. However, in lean-burn exhaust, there exists excess oxygen, which accelerates the catalytic oxidation of reduetants, and therefore decreasing efficiency of NOx reduction over the conventional threeway catalysts. At present, there are mainly three kinds of catalytic technology for lean-burn NOx removal,namely NO direct decomposition, selective catalytic reduction (SCR) and NOx storage and reduction (NSR). In this paper, the lean-burn combustion technique is briefly introduced, and the catalytic technology for lean-burn NOx removal is systematically reviewed.%稀薄燃烧(简称稀燃)技术能够使燃料在发动机内充分燃烧,既提高了燃油的经济性,同时又减少了温室气体CO2的排放,因而是一项节能减排的重要技术.但在稀燃条件下氧气大量过剩,加剧了三效催化剂对还原剂的催化氧化,降低了还原剂对NOx催化还原的效率.目前,国际上对稀燃气氛下NOx的消除主要采用NO直接分解、选择性催化还原(SCR)和NOx储存还原(NSR)等催化技术.本文对稀燃NOx催化消除技术进行了评述与展望.

  12. In situ DRIFTS studies on MnOx nanowires supported by activated semi-coke for low temperature selective catalytic reduction of NOx with NH3

    Science.gov (United States)

    Chen, Yan; Zhang, Zuotai; Liu, Lili; Mi, Liang; Wang, Xidong

    2016-03-01

    To mitigate the threat of NOx on the environment, MnOx nanowires were fabricated on activated semi-coke (MnOx NW/ASC) for the first time. The prepared MnOx NW/ASC was used for the low temperature selective catalytic reduction (SCR) of NOx with NH3, which achieved an efficiency of over 90% with a low loading content of 1.64 wt% at 150-210 °C. This high performance could be ascribed to synergistic effect between MnOx and ASC. Specifically, the large specific surface area and reducible property of ASC facilitated the dispersion of MnOx and the formation of Mn3+, respectively. Meanwhile, MnOx nanowires provided more redox sites and lattice oxygen species due to the coexistence of Mn3+ and Mn4+, which accelerated the catalytic cycle. The in situ DRIFTS studies revealed that ASC was conducive to the adsorption of NO and NH3. Most importantly, the existence of Mn3+ favored the formation of amide species and the subsequent reduction reaction. Furthermore, the Langmuir-Hinshelwood (L-H) route between coordinated NH3 and bidentate nitrate was predominating in the SCR process and responsible for the high catalytic activity at low temperature.

  13. Activity and hydrothermal stability of CeO2-ZrO2-WO3 for the selective catalytic reduction of NOx with NH3.

    Science.gov (United States)

    Song, Zhongxian; Ning, Ping; Zhang, Qiulin; Li, Hao; Zhang, Jinhui; Wang, Yancai; Liu, Xin; Huang, Zhenzhen

    2016-04-01

    A series of CeO2-ZrO2-WO3 (CZW) catalysts prepared by a hydrothermal synthesis method showed excellent catalytic activity for selective catalytic reduction (SCR) of NO with NH3 over a wide temperature of 150-550°C. The effect of hydrothermal treatment of CZW catalysts on SCR activity was investigated in the presence of 10% H2O. The fresh catalyst showed above 90% NOx conversion at 201-459°C, which is applicable to diesel exhaust NOx purification (200-440°C). The SCR activity results indicated that hydrothermal aging decreased the SCR activity of CZW at low temperatures (below 300°C), while the activity was notably enhanced at high temperature (above 450°C). The aged CZW catalyst (hydrothermal aging at 700°C for 8hr) showed almost 80% NOx conversion at 229-550°C, while the V2O5-WO3/TiO2 catalyst presented above 80% NOx conversion at 308-370°C. The effect of structural changes, acidity, and redox properties of CZW on the SCR activity was investigated. The results indicated that the excellent hydrothermal stability of CZW was mainly due to the CeO2-ZrO2 solid solution, amorphous WO3 phase and optimal acidity. In addition, the formation of WO3 clusters increased in size as the hydrothermal aging temperature increased, resulting in the collapse of structure, which could further affect the acidity and redox properties. PMID:27090708

  14. Simultaneous removal of SO2 and NOx with ammonia combined with gas-phase oxidation of NO using ozone

    Directory of Open Access Journals (Sweden)

    Guo Shaopeng

    2015-01-01

    Full Text Available A process for simultaneous desulfurization and denitrification was proposed, which was made up of ozone as the oxidizing agent for NO and ammonia solution as absorbent. The results showed that the presence of SO2 and the concentration changes of NO and SO2 have little impact on the oxidation of NO, the oxidation efficiency of NO can achieve over 90% when the molar ratio of O3/NO is 1.0. The presence of NOx had little effects on the absorption of SO2, an appropriate increase of SO2 concentration was favorable to the NOx absorption. The removal efficiency of SO2 and NOx reached 99.34% and 90.01% at pH 10, flow rate 0.95 Nm3/h, n[O3]/n[NO] 1.0, initial SO2 concentration 2000 mg/Nm3, initial NO concentration 200 mg/Nm3, ammonia concentration 0.3%, oxygen content of the simulated flue gas 12%, oxidation reaction temperature 423K and absorption reaction temperature 298K in the experimental system.

  15. Removal of formaldehyde over MnxCe1-xO2 catalysts: Thermal catalytic oxidation versus ozone catalytic oxidation

    Institute of Scientific and Technical Information of China (English)

    Jia Wei Li; Kuan Lun Pan; Sheng Jen Yu; Shaw Yi Yan; Moo Been Chang

    2014-01-01

    MnxCe1-xO2 (x:0.3-0.9) prepared by Pechini method was used as a catalyst for the thermal catalytic oxidation of formaldehyde (HCHO).At x =0.3 and 0.5,most of the manganese was incorporated in the fluorite structure of CeO2 to form a solid solution.The catalytic activity was best at x =0.5,at which the temperature of 100% removal rate is the lowest (270℃).The temperature for 100% removal of HCHO oxidation is reduced by approximately 40℃ by loading 5 wt.% CuOx into Mn0.5Ce0.5O2.With ozone catalytic oxidation,HCHO (61 ppm) in gas stream was completely oxidized by adding 506 ppm O3 over Mn0.5Ce0.5O2 catalyst with a GHSV (gas hourly space velocity) of 10,000 hr-1 at 25℃.The effect of the molar ratio of O3 to HCHO was also investigated.As O3/HCHO ratio was increased from 3 to 8,the removal efficiency of HCHO was increased from 83.3% to 100%.With O3/HCHO ratio of 8,the mineralization efficiency of HCHO to CO2 was 86.1%.At 25℃,the p-type oxide semiconductor (Mn0.5Ce0.5O2) exhibited an excellent ozone decomposition efficiency of 99.2%,which significantly exceeded that of n-type oxide semiconductors such as TiO2,which had a low ozone decomposition efficiency (9.81%).At a GHSV of 10,000 hr-1,[O3]/[HCHO] =3 and temperature of 25℃,a high HCHO removal efficiency (≥81.2%) was maintained throughout the durability test of 80 hr,indicating the long-term stability of the catalyst for HCHO removal.

  16. Synthesis and Characterisation of Porous Titania-Silica Composite Aerogel for NO(x) and Acetaldehyde Removal.

    Science.gov (United States)

    Lee, Kwang Young; Park, Se Min; Kim, Jong Beom; El Saliby, Ibrahim; Shahid, Mohammad; Kim, Geon-Joong; Shon, Ho Kyong; Kim, Jong-Ho

    2016-05-01

    In this study, the synthesis of porous titania-silica (TiO2-SiO2) composite aerogel at ambient pressure by using non-hazardous chemicals as a source of silica was investigated. TiO2-SiO2 composite aerogels were characterised and their photocatalytic performances were investigated for the removal efficiency of acetaldehyde and NO(x) under UV light. Results showed that porous composite aerogel with aggregated morphology, high surface area and an increased mesoporosity were formed. TiO2-SiO2(1.8) composite, with high Ti/Si ratio, showed the best results in terms of photocatalytic removal of acetaldehyde and nitrogen oxide.

  17. Synthesis and Characterisation of Porous Titania-Silica Composite Aerogel for NO(x) and Acetaldehyde Removal.

    Science.gov (United States)

    Lee, Kwang Young; Park, Se Min; Kim, Jong Beom; El Saliby, Ibrahim; Shahid, Mohammad; Kim, Geon-Joong; Shon, Ho Kyong; Kim, Jong-Ho

    2016-05-01

    In this study, the synthesis of porous titania-silica (TiO2-SiO2) composite aerogel at ambient pressure by using non-hazardous chemicals as a source of silica was investigated. TiO2-SiO2 composite aerogels were characterised and their photocatalytic performances were investigated for the removal efficiency of acetaldehyde and NO(x) under UV light. Results showed that porous composite aerogel with aggregated morphology, high surface area and an increased mesoporosity were formed. TiO2-SiO2(1.8) composite, with high Ti/Si ratio, showed the best results in terms of photocatalytic removal of acetaldehyde and nitrogen oxide. PMID:27483782

  18. Identification of the arsenic resistance on MoO3 doped CeO2/TiO2 catalyst for selective catalytic reduction of NOx with ammonia.

    Science.gov (United States)

    Li, Xiang; Li, Xiansheng; Li, Junhua; Hao, Jiming

    2016-11-15

    Arsenic resistance on MoO3 doped CeO2/TiO2 catalysts for selective catalytic reduction of NOx with NH3 (NH3-SCR) is investigated. It is found that the activity loss of CeO2-MoO3/TiO2 caused by As oxide is obvious less than that of CeO2/TiO2 catalysts. The fresh and poisoned catalysts are compared and analyzed using XRD, Raman, XPS, H2-TPR and in situ DRIFTS. The results manifest that the introduction of arsenic oxide to CeO2/TiO2 catalyst not only weakens BET surface area, surface acid sites and adsorbed NOx species, but also destroy the redox circle of Ce(4+) to Ce(3+) because of interaction between Ce and As. When MoO3 is added into CeO2/TiO2 system, the main SCR reaction path are found to be changed from the reaction between coordinated NH3 and ad-NOx species to that between an amide and gaseous NO. Additionally, for CeO2-MoO3/TiO2 catalyst, As toxic effect on active sites CeO2 can be released because of stronger As-Mo interaction. Moreover, not only are the reactable Brønsted and Lewis acid sites partly restored, but the cycle of Ce(4+) to Ce(3+) can also be free to some extent.

  19. Modeling of adsorber/desorber/catalytic reactor system for ethylene oxide removal

    OpenAIRE

    ZELJKO B. GRBAVCIC; BOSKO V. GRBIC; ZORANA LJ. ARSENIJEVIC

    2004-01-01

    The removal of ethylene oxide (EtO) in a combined system adsorber/desorber/catalytic reactor has been investigated. The combined system was a modified draft tube spouted bed reactor loaded with Pt/Al2O3 catalyst. The annular region was divided into two sectons, the hot section contained about 7 % of catalyst and it behaved as a desorber and catalytic incinerator, while the cold section, with the rest of the catalyst, behaved as a sorber. The catalyst particles were circulated between the two ...

  20. Progress in catalytic membrane reactors for removing sulfur from natural gas

    Institute of Scientific and Technical Information of China (English)

    TAO Chang-yuan; LIU Zuo-hua; DU Jun; LIU Ren-long

    2007-01-01

    Increasingly high requirement driven by environmental concern leads to more rigorous standards for sulfur dosage in fuel. Natural gas desulfurization is an important unit for industrial natural gas process. Catalytic membrane reactor for sulfur compounds removal is a newly emerged and integrated membrane technology. We reviewed the current progress for desulfurization of natural gas with membrane process, and predicted that the process combined with catalytic membrane reactor and microwave irradiation for desulfurization of natural gas might be an integrated and promising unit for large scale desulfurization with high efficiency.

  1. Removal of Pollutants by Atmospheric Non Thermal Plasmas

    CERN Document Server

    Khacef, Ahmed; Pouvesle, Jean Michel; Van, Tiep Le

    2008-01-01

    Results on the application of non thermal plasmas in two environmentally important fields: oxidative removal of VOC and NOx in excess of oxygen were presented. The synergetic application of a plasma-catalytic treatment of NOx in excess of oxygen is also described.

  2. Low concentration volatile organic pollutants removal in combined adsorber-desorber-catalytic reactor system

    Directory of Open Access Journals (Sweden)

    Arsenijević Zorana

    2008-01-01

    Full Text Available The removal of volatile organic compounds (VOCs from numerous emission sources is of crucial importance due to more rigorous demands on air quality. Different technologies can be used to treat the VOCs from effluent gases: absorption, physical adsorption, open flame combustion, thermal and catalytic incineration. Their appropriateness for the specific process depends on several factors such as efficiency, energy consumption, secondary pollution, capital investments etc. The distinctive features of the catalytic combustion are high efficiency and selectivity toward be­nign products, low energy consumption and absence of secondary polluti­on. The supported noble catalysts are widely used for catalytic incineration due to their low ignition temperatures and high thermal and chemical stability. In our combined system adsorption and desorption are applied in the spouted bed with draft tube (SBDT unit. The annular zone, loaded with sorbent, was divided in adsorption and desorption section. Draft tube enabled sorbent recirculation between sections. Combustion of desorbed gases to CO2 and water vapor are realized in additive catalytic reactor. This integrated device provided low concentrations VOCs removal with reduced energy consumption. Experiments were conducted on a pilot unit of 220 m3/h nominal capacity. The sorbent was activated carbon, type K81/B - Trayal Corporation, Krusevac. A sphere shaped commercial Pt/Al2O3 catalyst with "egg-shell" macro-distribution was used for the investigation of xylene deep oxidation. Within this paper the investigations of removal of xylene vapors, a typical pollutant in production of liquid pesticides, in combined adsorber/desorber/catalytic reactor system is presented.

  3. ACIDIC REMOVAL OF METALS FROM FLUIDIZED CATALYTIC CRACKING CATALYST WASTE ASSISTED BY ELECTROKINETIC TREATMENT

    OpenAIRE

    R. B. G. Valt; A. N. Diógenes; L. S. Sanches; N. M. S. Kaminari; M. J. J. S. Ponte; H. A. Ponte

    2015-01-01

    AbstractOne of the main uses of catalysts in the oil industry is in the fluidized catalytic cracking process, which generates large quantities of waste material after use and regeneration cycles and that can be treated by the electrokinetic remediation technique, in which the contaminant metals are transported by migration. In this study, deactivated FCC catalyst was characterized before and after the electrokinetic remediation process to evaluate the amount of metal removed, and assess struc...

  4. WO3/CeO2/TiO2 Catalysts for Selective Catalytic Reduction of NO(x) by NH3: Effect of the Synthesis Method.

    Science.gov (United States)

    Michalow-Mauke, Katarzyna A; Lu, Ye; Ferri, Davide; Graule, Thomas; Kowalski, Kazimierz; Elsener, Martin; Kröcher, Oliver

    2015-01-01

    WO3/CeO2/TiO2, CeO2/TiO2 and WO3/TiO2 catalysts were prepared by wet impregnation. CeO2/TiO2 and WO3/TiO2 showed activity towards the selective catalytic reduction (SCR) of NO(x) by NH3, which was significantly improved by subsequent impregnation of CeO/TiO2 with WO3. Catalytic performance, NH3 oxidation and NH3 temperature programmed desorption of wet-impregnated WO3/CeO2/TiO2 were compared to those of a flame-made counterpart. The flame-made catalyst exhibits a peculiar arrangement of W-Ce-Ti-oxides that makes it very active for NH3-SCR. Catalysts prepared by wet impregnation with the aim to mimic the structure of the flame-made catalyst were not able to fully reproduce its activity. The differences in the catalytic performance between the investigated catalysts were related to their structural properties and the different interaction of the catalyst components.

  5. [Experiment study on the aqueous removal of SO2 by Mn2+ catalytic ozonation].

    Science.gov (United States)

    Ma, Shuang-Chen; Su, Min; Ma, Jing-Xiang; Sun, Yun-Xue; Jin, Xin; Zhao, Yi

    2009-11-01

    The removal of SO2 by Mn2+ catalytic aqueous ozonation was investigated by experiment, so as to find the effects of Mn2+ for aqueous removal of SO2 by ozonation. The concentration curve of ozone was drawn by standard iodine method. The operating factors included mole ratio of ozone to sulfur dioxide and concentration of Mn2+. When absorption solution has no Mn2+, the removal efficiency of SO2 was 35% at [O3 ]/[SO2 ] = 0.5,but the efficiency was 70% when Mn2+ was put into absorption solution at the same value of [O3 ]/[SO2].With the increasing of [3O]/[SO2], the removal efficiency of SO2 increases. And as concentration of Mn2+ increases, the efficiency also increases. There is an appropriate concentration range which is 1.2 x 10(-2)-1.2 x 10(-1) mol/L for Mn2+.

  6. Near-Zero Emissions Oxy-Combustion Flue Gas Purification Task 2: SOx/Nox/Hg Removal for High Sulfur Coal

    Energy Technology Data Exchange (ETDEWEB)

    Nick Degenstein; Minish Shah; Doughlas Louie

    2012-05-01

    The goal of this project is to develop a near-zero emissions flue gas purification technology for existing PC (pulverized coal) power plants that are retrofitted with oxy-combustion technology. The objective of Task 2 of this project was to evaluate an alternative method of SOx, NOx and Hg removal from flue gas produced by burning high sulfur coal in oxy-combustion power plants. The goal of the program was not only to investigate a new method of flue gas purification but also to produce useful acid byproduct streams as an alternative to using a traditional FGD and SCR for flue gas processing. During the project two main constraints were identified that limit the ability of the process to achieve project goals. 1) Due to boiler island corrosion issues >60% of the sulfur must be removed in the boiler island with the use of an FGD. 2) A suitable method could not be found to remove NOx from the concentrated sulfuric acid product, which limits sale-ability of the acid, as well as the NOx removal efficiency of the process. Given the complexity and safety issues inherent in the cycle it is concluded that the acid product would not be directly saleable and, in this case, other flue gas purification schemes are better suited for SOx/NOx/Hg control when burning high sulfur coal, e.g. this project's Task 3 process or a traditional FGD and SCR.

  7. Amperometric NOx-sensor for Combustion Exhaust Gas Control. Studies on transport properties and catalytic activity of oxygen permeable ceramic membranes

    International Nuclear Information System (INIS)

    The aim of the research described in this thesis is the development of a mixed conducting oxide layer, which can be used as an oxygen permselective membrane in an amperometric NOx sensor. The sensor will be used in exhaust gas systems. The exhaust gas-producing engine will run in the lean mix mode. The preparation of this sensor is carried out using screen-printing technology, in which the different layers of the sensor are applied successively. Hereafter, a co-firing step is applied in which all layers are sintered together. This co-firing step imposes several demands on the selection of materials. The design specifications of the sensor further include requirements concerning the operating temperature, measurement range and overall stability. The operating temperature of the sensor varies between 700 and 850C, enabling measurement of NOx concentrations between 50 and 1200 ppm with a measurement accuracy of 10 ppm. Concerning the stability of the sensor, it must withstand the exhaust gas atmosphere containing, amongst others, smoke, acids, abrasive particles and sulphur. Because of the chosen lean-mix engine concept, in which the fuel/air mixture switches continuously between lean (excess oxygen) and fat (excess fuel) mixtures, the sensor must withstand alternately oxidising and reducing atmospheres. Besides, it should be resistant to thermal shock and show no cross-sensitivity of NOx with other exhaust gas constituents like oxygen and hydrocarbons. The response time should be short, typically less than 500 ms. Because of the application in combustion engines of cars, the operational lifetime should be longer than 10 years. Demands on the mixed conducting oxide layer include the following ones. The layer should show minimal catalytic activity towards NOx-reduction. The oxygen permeability must be larger than 6.22 10-8 mol/cm2s at a layer thickness between 3-50 μm. Since the mixed conducting oxide layer is coated on the YSZ electrolyte embodiment, the two

  8. Selective catalytic NOx reduction on Antimony promoted V2O5-Sb/TiO2 catalyst

    Institute of Scientific and Technical Information of China (English)

    HA Heon Phil; CHUNG Soon Hyo; OH Young Joo

    2006-01-01

    Quantum chemical calculation was carried out to choose a promoter which can reduce the poisoning of V2O5/TiO2 catalysts by SO2.Several atoms were chosen as candidates and new catalysts were synthesized by impregnation method.The NOx conversion rate was measured at temperatures between 100 and 400 ℃ and poisoning effect was investigated.The most promising candidate promoter, Se, was excluded because of its high vapor pressure.On the other hand, Sb shows best promoting properties.Sb promoted catalyst reaches the maximum NOx conversion rate at 250 ℃.It also shows considerably enhanced resistance to poisoning of V2O5/TiO2 catalysts by SO2.

  9. Roles of Promoters in V2O5/TiO2 Catalysts for Selective Catalytic Reduction of NOx with NH3: Effect of Order of Impregnation.

    Science.gov (United States)

    Youn, Seunghee; Song, Inhak; Kim, Do Heui

    2016-05-01

    Recently, various promoters for commercial selective catalytic reduction (SCR) catalysts are used to improve DeNOx activity at low temperature. We aimed at finding the optimum condition to prepare V2O5/TiO2 catalyst by changing promoters (W, Ce, Zr and Mn), not only for improving SCR reactivity, but also for reducing N2O formation at high temperature. In addition, we changed the order of impregnation between promoter and vanadium precursors on TiO2 support and observed its effect on activity and N2O selectivity. We utilized various analytical techniques, such as N2 adsorption-desorption, X-ray Diffraction (XRD), Raman spectroscopy, UV-visible Diffuse Reflectance Spectroscopy (UV-vis DRS) and Temperature Programmed Reduction with hydrogen (H2-TPR) to investigate the physicochemical properties of V2O5/TiO2 catalysts. It was found that W and Ce added V2O5/TiO2 catalysts showed the most active DeNOx properties at low temperature. Additionally, the difference in impregnation order affected the SCR activity. The superiority of low temperature activity of the vanadium firstly added catalysts (W or Ce/V/TiO2) is attributed to the formation of more polymerized V2O5 on the sample. PMID:27483756

  10. [Nitric Oxide Removal with a Fe-TiO₂/PSF Hybrid Catalytic Membrane Bioreactor].

    Science.gov (United States)

    Li, Bao-ren; Chen, Zhou-yang; Wang, Jian-bin; Zhang, Zai-li; Fan, Qing-juan; Wei, Zai-shan

    2016-03-15

    The Fe-doped titanium dioxide (Fe-TiO₂) was prepared by the sol-gel method and was loaded on polysulfone (PSF) hollow fiber membrane. A novel Fe-TiO₂/PSF hybrid catalytic membrane biofilm reactor (HCMBfR) was investigated for nitric oxide removal, to further improve the elimination capacity. HCMBfR exhibited a good stability in the 180-day operation period, the NO removal efficiency was up to 93.2% and the maximum elimination capacity reached 167.1 g · (m³ · h)⁻1. The additional use of the biofilm to wet Fe-TiO₂/PSF membrane catalysis reactor led to the enhancement of NO removal efficiency from 59. 5% to 66% . The NO removal efficiency in the intimate coupling of Fe-TiO₂/PSF hybrid catalytic membrane and biofilm reactor ( HCMBfR) increased from 1.4% to 13% as compared to that of the membrane biofilm reactor (MBfR) only. The optimal illumination intensity, gas residence time, pH and nC/nN were 670 lx, 9 a, 6.8-7.2 and 3.7, respectively. PMID:27337874

  11. Molecular Simulation of Naphthenic Acid Removal on Acidic Catalyst (Ⅰ) Mechanism of Catalytic Decarboxylation

    Institute of Scientific and Technical Information of China (English)

    Fu Xiaoqin; Dai Zhenyu; Tian Songbai; Hou Suandi; Wang Xieqing

    2008-01-01

    In this paper, the charge distribution, the chemical bond order and the reactive performance of carboxylic acid model compounds on acidic catalyst were investigated by using molecular simulation technology. The simulation results showed that the bond order of C-O was higher than that of C-C,and C-C bond connected to the carbon atom in the carboxyl radical had the lowest bond order. The charge distributions of model naphthenic acids were similar in characteristics that the negative charges were concentrated on carboxyls. According to the simulation results, the mechanisms of catalytic decarboxylation over acidic solid catalyst were proposed, and a new route was put forward regarding removal of the naphthenic acid from crude oil through catalytic decarboxylation.

  12. Carbonates-based noble metal-free lean NOx trap catalysts MOx-K2CO3/K2Ti8O17 (M = Ce, Fe, Cu, Co) with superior catalytic performance

    Science.gov (United States)

    Zhang, Yuxia; You, Rui; Liu, Dongsheng; Liu, Cheng; Li, Xingang; Tian, Ye; Jiang, Zheng; Zhang, Shuo; Huang, Yuying; Zha, Yuqing; Meng, Ming

    2015-12-01

    A series of base metal-based lean NOx trap (LNT) catalysts MOx-K2CO3/K2Ti8O17 (M = Ce, Fe, Cu, Co) were synthesized by successive impregnations and employed for the storage and reduction of NOx in the emissions of lean-burn engines at 350 °C. The XRD and XANES/EXAFS results reveal that the active phases in the corresponding catalysts exist as CeO2, Fe2O3, CuO and Co3O4, respectively. Among all the catalysts, CoOx-K2CO3/K2Ti8O17 exhibits the best performance, which cannot only trap the NOx quickly and completely at lean condition, giving the highest storage capacity (3.32 mmol/g) reported so far, but also reduce the NOx at rich condition, showing a NOx reduction percentage as high as 99.0%. Meanwhile, this catalyst displays an ultralow NOx to N2O selectivity (0.3%) during NOx reduction. The excellent performance of CoOx-K2CO3/K2Ti8O17 results from its largest amount of surface active oxygen species as revealed by XPS, O2-TPD and NO-TPD. HRTEM, FT-IR and CO2-TPD results illustrate that several kinds of K species such as sbnd OK groups, K2O, surface carbonates and bulk or bulk-like carbonates coexist in the catalysts. Based upon the in situ DRIFTS results, the participation of K2CO3 in NOx storage is confirmed, and the predominant NOx storage species is revealed as bidentate nitrites formed via multiple kinetic pathways. The low cost and high catalytic performance of the CoOx-based LNT catalyst make it most promising for the substitution of noble metal-based LNT catalysts.

  13. Removal performance and mechanism of ibuprofen from water by catalytic ozonation using sludge-corncob activated carbon as catalyst.

    Science.gov (United States)

    Wang, Hongjuan; Zhang, Liqiu; Qi, Fei; Wang, Xue; Li, Lu; Feng, Li

    2014-09-01

    To discover the catalytic activity of sludge-corncob activated carbon in catalytic ozonation of Ibuprofen, the performance of sludge-corncob activated carbon and three selected commercial activated carbons as catalysts in catalytic ozonation was investigated. The observation indicates the degradation rate of Ibuprofen increases significantly in the presence of sludge-corncob activated carbon and the catalytic activity of sludge-corncob activated carbon is much higher than that of the other three commercial activated carbons. Ibuprofen's removal rate follows pseudo-first order kinetics model well. It is also found that the adsorption removal of Ibuprofen by sludge-corncob activated carbon is less than 30% after 40 min. And the removal efficiency of Ibuprofen in the hybrid ozone/sludge-corncob activated carbon system is higher than the sum of sludge-corncob activated carbon adsorption and ozonation alone, which is a supportive evidence for catalytic reaction. In addition, the results of radical scavenger experiments demonstrate that catalytic ozonation of Ibuprofen by sludge-corncob activated carbon follows a hydroxyl radical reaction pathway. During ozonation of Ibuprofen in the presence of activated carbon, ozone could be catalytically decomposed to form hydrogen peroxide, which can promote the formation of hydroxyl radical. The maximum amount of hydrogen peroxide occurs in the presence of sludge-corncob activated carbon, which can explain why sludge-corncob activated carbon has the best catalytic activity among four different activated carbons.

  14. Pathway of FeEDTA transformation and its impact on performance of NOx removal in a chemical absorption-biological reduction integrated process.

    Science.gov (United States)

    Li, Wei; Zhao, Jingkai; Zhang, Lei; Xia, Yinfeng; Liu, Nan; Li, Sujing; Zhang, Shihan

    2016-01-01

    A novel chemical absorption-biological reduction (CABR) integrated process, employing ferrous ethylenediaminetetraacetate (Fe(II)EDTA) as a solvent, is deemed as a potential option for NOx removal from the flue gas. Previous work showed that the Fe(II)EDTA concentration was critical for the NOx removal in the CABR process. In this work, the pathway of FeEDTA (Fe(III)/Fe(II)-EDTA) transformation was investigated to assess its impact on the NOx removal in a biofilter. Experimental results revealed that the FeEDTA transformation involved iron precipitation and EDTA degradation. X-ray photoelectron spectroscopy analysis confirmed the iron was precipitated in the form of Fe(OH)3. The iron mass balance analysis showed 44.2% of the added iron was precipitated. The EDTA degradation facilitated the iron precipitation. Besides chemical oxidation, EDTA biodegradation occurred in the biofilter. The addition of extra EDTA helped recover the iron from the precipitation. The transformation of FeEDTA did not retard the NO removal. In addition, EDTA rather than the iron concentration determined the NO removal efficiency.

  15. Removal of elemental mercury by TiO₂doped with WO₃ and V₂O₅ for their photo- and thermo-catalytic removal mechanisms.

    Science.gov (United States)

    Shen, Huazhen; Ie, Iau-Ren; Yuan, Chung-Shin; Hung, Chung-Hsuang; Chen, Wei-Hsiang

    2016-03-01

    The catalytic removal of Hg(0) was investigated to ascertain whether the catalysts could simultaneously possess both thermo- and photo-catalytic reactivity. The immobilized V2O5/TiO2 and WO3/TiO2 catalysts were synthesized by sol-gel method and then coated on the surface of glass beads for catalytic removal of Hg(0). They were also characterized by SEM, BET, XRD, UV-visible, and XPS analysis, and their catalytic reactivity was tested under 100-160 °C under the near-UV irradiation. The results indicated that V2O5/TiO2 solely possessed the thermo-catalytic reactivity while WO3/TiO2 only had photo-catalytic reactivity. Although the synthesis catalytic reactivity has not been found for these catalysts up to date, but compared with TiO2, the removal efficiencies of Hg(0) at 140 and 160 °C were enhanced; particularly, the efficiency was improved from 20 % at 160 °C by TiO2 to nearly 90 % by WO3/TiO2 under the same operating conditions. The effects of doping amount of V2O5 and WO3 were also investigated, and the results showed that 10 % V2O5 and 5 % WO3/TiO2 were the best immobilized catalysts for thermo- and photo-catalytic reactivity, respectively. The effect of different influent concentrations of Hg(0) was demonstrated that the highest concentration of Hg(0) led to the best removal efficiencies for V2O5/TiO2 and WO3/TiO2 at 140 and 160 °C, because high Hg(0) concentration increased the mass transfer rate of Hg(0) toward the surface of catalysts and drove the reaction to proceed. At last, the effect of single gas component on the removal of Hg(0) was also investigated. PMID:26590063

  16. Structural characterization and catalytic activity of Pt dendrimer encapsulated nanoparticles supported over Al2O3 for SCR of NOx.

    Science.gov (United States)

    Bae, HyunSook; Rao, Komateedi N; Ha, HeonPhil

    2011-07-01

    Pt/Al2O3 and Pt-Mg/Al2O3 nano composites were successfully prepared by dendrimer templated synthesis route. The obtained dendritic nanoparticles were dispersed in alumina support and they were evaluated for SCR of NOx using methane as reductant. Thermal analysis results of uncalcined samples revealed that the oxygen can accelerate the rate of dendrimer shell decomposition. X-ray diffractograms of 500 degrees C calcined samples disclosed the amorphous nature of materials, whereas 1000 degrees C air calcined samples showed enhanced crystallinity as well as diffraction pattern corresponding to Pt and PtO. HRTEM images of Pt40-G4OH dendritic nanoparticles showed uniform particulate distribution with average particle size of 2.4 nm. The STEM results of 0.5 Pt/Al2O3 sample calcined at 500 degrees C exhibited a wide range of particles between 2 and 20 nm. This indicates the huge segregation of platinum metal particles during impregnation and subsequent calcination. Among the synthesized materials 0.5 wt% Pt/Al2O3 sample showed excellent conversion and selectivity for SCR of NOx.

  17. TiO2-Supported Binary Metal Oxide Catalysts for Low-temperature Selective Catalytic Reduction of NOx with NH3

    Institute of Scientific and Technical Information of China (English)

    WU Bi-jun; LIU Xiao-qin; XIAO Ping; WANG Shu-gang

    2008-01-01

    Binary metal oxide(MnOx-A/TiO2) catalysts were prepared by adding the second metal to manganese oxides supported on titanium dioxide(TiO2),where,A indicates Fe2O3,WO3,MoO3,and Cr2O3.Their catalytic activity,N2 selectivity,and SO2 poisonous tolerance were investigated.The catalytic performance at low temperatures decreased in the following order:Mn-W/TiO2>Mn-Fe/TiO2>Mn-Cr/TiO2>Mn-Mo/TiO2,whereas the N2 selectivity decreased in the order:Mn-Fe/TiO2>Mn-W/TiO2>Mn-Mo/TiO2>Mn-Cr/TiO2.In the presence of 0.01% SO2 and 6% H2O,the NOx conversions in the presence of Mn-W/TiO2,Mn-Fe/TiO2,or Mn-Mo/TiO2 maintain 98.5%,95.8% and 94.2%,respectively,after 8 h at 120 ℃ at GHSV 12600 h-1.As effective promoters,WO3 and Fe2O3 can increase N2 selectivity and the resistance to SO2 of MnOx/TiO2 significantly.The Fourier transform infrared(FTIR) spectra of NH3 over WO3 show the presence of Lewis acid sites.The results suggest that WO3 is the best promoter of MnOx/TiO2,and Mn-W/TiO2 is one of the most active catalysts for the low temperature selective catalytic reduction of NO with NH3.

  18. Methods for sulfate removal in liquid-phase catalytic hydrothermal gasification of biomass

    Science.gov (United States)

    Elliott, Douglas C; Oyler, James

    2013-12-17

    Processing of wet biomass feedstock by liquid-phase catalytic hydrothermal gasification must address catalyst fouling and poisoning. One solution can involve heating the wet biomass with a heating unit to a pre-treatment temperature sufficient for organic constituents in the feedstock to decompose, for precipitates of inorganic wastes to form, for preheating the wet feedstock in preparation for subsequent removal of soluble sulfate contaminants, or combinations thereof. Processing further includes reacting the soluble sulfate contaminants with cations present in the feedstock material to yield a sulfate-containing precipitate and separating the inorganic precipitates and/or the sulfate-containing precipitates out of the wet feedstock. Having removed much of the inorganic wastes and the sulfate contaminants that can cause poisoning and fouling, the wet biomass feedstock can be exposed to the heterogenous catalyst for gasification.

  19. The Nicotinamide Adenine Dinucleotide Phosphate Oxidase Homologues NOX1 and NOX2/gp91phox Mediate Hepatic Fibrosis in Mice

    OpenAIRE

    Paik, Yong-Han; Iwaisako, Keiko; Seki, Ekihiro; Inokuchi, Sayaka; Schnabl, Bernd; Österreicher, Christoph H.; Kisseleva, Tatiana; Brenner, David A

    2011-01-01

    NADPH oxidase (NOX) is a multicomponent enzyme that mediates electron transfer from NADPH to molecular oxygen, which leads to the production of superoxide. NOX2/gp91phox is a catalytic subunit of NOX expressed in phagocytic cells. Several homologues of NOX2, including NOX1, have been identified in non-phagocytic cells. We investigated the contributory role of NOX1 and NOX2 in hepatic fibrosis. Hepatic fibrosis was induced in wild-type (WT) mice, NOX1-knockout (NOX1KO) mice, and NOX2-knockout ...

  20. A Comparative Study of N2O Formation during the Selective Catalytic Reduction of NOx with NH3 on Zeolite Supported Cu Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Hai-Ying; Wei, Zhehao; Kollar, Marton; Gao, Feng; Wang, Yilin; Szanyi, Janos; Peden, Charles HF

    2015-09-01

    A comparative study was carried out on a small-pore CHA.Cu and a large-pore BEA.Cu zeolite catalyst to understand the lower N2O formation on small-pore zeolite supported Cu catalysts in the selective catalytic reduction (SCR) of NOx with NH3. On both catalysts, the N2O yield increases with an increase in the NO2/NOx ratios of the feed gas, suggesting N2O formation via the decomposition of NH4NO3. Temperature-programmed desorption experiments reveal that NH4NO3 is more stable on CHA.Cu than on BEA.Cu. In situ FTIR spectra following stepwise (NO2 + O2) and (15NO + NH3 + O2) adsorption and reaction, and product distribution analysis using isotope-labelled reactants, unambiguously prove that surface nitrate groups are essential for the formation of NH4NO3. Furthermore, CHA.Cu is shown to be considerably less active than BEA.Cu in catalyzing NO oxidation and the subsequent formation of surface nitrate groups. Both factors, i.e., (1) the higher thermal stability of NH4NO3 on CHA.Cu, and (2) the lower activity for this catalyst to catalyze NO oxidation and the subsequent formation of surface nitrates, likely contribute to the higher SCR selectivity with less N2O formation on this catalyst as compared to BEA.Cu. The latter is determined as the primary reason since surface nitrates are the source that leads to the formation of NH4NO3 on the catalysts.

  1. Supported, Alkali-Promoted Cobalt Oxide Catalysts for NOx Removal from Coal Combustion Flue Gases

    Energy Technology Data Exchange (ETDEWEB)

    Morris D. Argyle

    2005-12-31

    A series of cobalt oxide catalysts supported on alumina ({gamma}-Al{sub 2}O{sub 3}) were synthesized with varying contents of cobalt and of added alkali metals, including lithium, sodium, potassium, rubidium, and cesium. Unsupported cobalt oxide catalysts and several cobalt oxide catalysts supported ceria (CeO{sub 2}) with varying contents of cobalt with added potassium were also prepared. The catalysts were characterized with UV-visible spectroscopy and were examined for NO{sub x} decomposition activity. The CoO{sub x}/Al{sub 2}O{sub 3} catalysts and particularly the CoO{sub x}/CeO{sub 2} catalysts show N{sub 2}O decomposition activity, but none of the catalysts (unsupported Co{sub 3}O{sub 4} or those supported on ceria or alumina) displayed significant, sustained NO decomposition activity. For the Al{sub 2}O{sub 3}-supported catalysts, N{sub 2}O decomposition activity was observed over a range of reaction temperatures beginning about 723 K, but significant (>50%) conversions of N{sub 2}O were observed only for reaction temperatures >900 K, which are too high for practical commercial use. However, the CeO{sub 2}-supported catalysts display N{sub 2}O decomposition rates similar to the Al{sub 2}O{sub 3}-supported catalysts at much lower reaction temperatures, with activity beginning at {approx}573 K. Conversions of >90% were achieved at 773 K for the best catalysts. Catalytic rates per cobalt atom increased with decreasing cobalt content, which corresponds to increasing edge energies obtained from the UV-visible spectra. The decrease in edge energies suggests that the size and dimensionality of the cobalt oxide surface domains increase with increasing cobalt oxide content. The rate data normalized per mass of catalyst that shows the activity of the CeO{sub 2}-supported catalysts increases with increasing cobalt oxide content. The combination of these data suggest that supported cobalt oxide species similar to bulk Co{sub 3}O{sub 4} are inherently more active than

  2. AMMONIA-FREE NOx CONTROL SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Song Wu; Zhen Fan; Andrew H. Seltzer; Richard G. Herman

    2006-06-01

    This report describes a novel NOx control system that has the potential to drastically reduce cost, and enhance performance, operation and safety of power plant NOx control. The new system optimizes the burner and the furnace to achieve very low NOx levels and to provide an adequate amount of CO, and uses the CO for reducing NO both in-furnace and over a downstream AFSCR (ammonia-free selective catalytic reduction) reactor. The AF-SCR combines the advantages of the highly successful SCR technology for power plants and the TWC (three-way catalytic converter) widely used on automobiles. Like the SCR, it works in oxidizing environment of combustion flue gas and uses only base metal catalysts. Like the TWC, the AF-SCR removes NO and excess CO simultaneously without using any external reagent, such as ammonia. This new process has been studied in a development program jointed funded by the US Department of Energy and Foster Wheeler. The report outlines the experimental catalyst work performed on a bench-scale reactor, including test procedure, operating conditions, and results of various catalyst formulations. Several candidate catalysts, prepared with readily available transition metal oxides and common substrate materials, have shown over 80-90% removal for both NO and CO in oxidizing gas mixtures and at elevated temperatures. A detailed combustion study of a 400 MWe coal-fired boiler, applying computational fluid dynamics techniques to model boiler and burner design, has been carried out to investigate ways to optimize the combustion process for the lowest NOx formation and optimum CO/NO ratios. Results of this boiler and burner optimization work are reported. The paper further discusses catalyst scale-up considerations and the conceptual design of a 400 MWe size AF-SCR reactor, as well as economics analysis indicating large cost savings of the ammonia-free NOx control process over the current SCR technology.

  3. State Estimation in the Automotive SCR DeNOx Process

    DEFF Research Database (Denmark)

    Zhou, Guofeng; Jørgensen, John Bagterp; Duwig, Christophe;

    2012-01-01

    Selective catalytic reduction (SCR) of nitrogen oxides (NOx) is a widely applied diesel engine exhaust gas after-treatment technology. For effective NOx removal in a transient operating automotive application, controlled dosing of urea can be used to meet the increasingly restrictive legislations...... on exhaust gas emissions. For advanced control, e.g. Model Predictive Control (MPC), of the SCR process, accurate state estimates are needed. We investigate the performance of the ordinary and the extended Kalman filters based on a simple first principle system model. The performance is tested through...

  4. Preparation of zeolite supported TiO2, ZnO and ZrO2 and the study on their catalytic activity in NOx reduction and 1-pentanol dehydration

    Science.gov (United States)

    Fatimah, Is

    2016-03-01

    Preparation of zeolite supported TiO2, ZnO and ZrO2 and their catalytic activity was studied. Activated natural zeolite from Indonesia was utilized for the preparation and catalytic activity test on NOx reduction by NH3 and also 1-pentanol dehydration were examined. Physicochemical characterization of materials was studied by x-ray diffraction (XRD) measurement, scanning electron microscope, solid acidity determination and also gas sorption analysis. The results confirmed that the preparation gives some improvements on physicochemical characters suitable for catalysis mechanism in those reactions. Solid acidity and specific surface area contributed significantly to the activity.

  5. Modeling of adsorber/desorber/catalytic reactor system for ethylene oxide removal

    Directory of Open Access Journals (Sweden)

    ZELJKO B. GRBAVCIC

    2004-12-01

    Full Text Available The removal of ethylene oxide (EtO in a combined system adsorber/desorber/catalytic reactor has been investigated. The combined system was a modified draft tube spouted bed reactor loaded with Pt/Al2O3 catalyst. The annular region was divided into two sectons, the “hot” section contained about 7 % of catalyst and it behaved as a desorber and catalytic incinerator, while the “cold” section, with the rest of the catalyst, behaved as a sorber. The catalyst particles were circulated between the two sections by use of a draft tube riser. The Computational Fluid Dynamics (CFD program package FLUENT was used for simulations of the operation of the combined system. In addition, a one-dimensional numerical model for the operation of the packed bed reactor was compared with the corresponding FLUENT calculations. The results of the FLUENT simulations are in very good agreement with the experimental observations, as well as with the results of the one-dimensional numerical simulations.

  6. Laboratory test reactor for the investigation of liquid reducing agents in the selective catalytic reduction of NOx

    Science.gov (United States)

    Peitz, D.; Bernhard, A.; Elsener, M.; Kröcher, O.

    2011-08-01

    A test reactor was designed and built for investigating liquid reducing agents in the selective catalytic reduction (SCR) process in the laboratory. The design of the experimental setup is described in detail and its performance was evaluated. Using a glass nebulizer, liquid reducing agents were sprayed directly onto a catalyst positioned in a heated glass reactor with a length of 250 mm and an internal diameter of 20.4 mm or 40 mm. Model exhaust gases were mixed from individual gas components and were heated up to 450 °C in a heat exchanger before entering the reactor. The off-gas was analyzed using two complimentary techniques, a multi-component online FTIR gas analysis and a liquid quench gas absorption setup, to detect higher molecular compounds and aerosols. Due to the versatility of construction, processes not related to SCR, but involving three-phase reactions with gases, liquids and a catalyst, can also be investigated.

  7. Assessment and identification of some novel NOx reducing reagents for SNCR process

    International Nuclear Information System (INIS)

    Nitrogen oxides (NOx) are one of the most hazardous air pollutants arising from the combustion processes. Because of the implementation of strict emission limits many NOx removal technologies have been developed. In the present work post combustion NOx removal technique that is Selective Non-Catalytic Reduction (SNCR) has been investigated in a pilot scale 150 kW combustion rig facility. Investigation has been performed using some novel NOx reducing reagents like urea, ammonium carbonate and mixture of their 50%-50% aqueous solution within the temperature range of 700 to 1200 deg. C., at 1.1% excess oxygen and background NOx level of 500 ppm. The effects of these reagents were determined in term of their temperature characteristics and molar ratio. Among the reducing reagents used urea solution gave the highest NOx removal efficiency (81%) and was attractive due to its superior high temperature (1000 to 1150 deg. C) performance, ammonium carbonate was more effective at lower temperature range (850 to 950 deg. C) though its efficiency (32%) was lower than urea, while 50-50% solution of urea and ammonium carbonate gave higher efficiency than ammonium carbonate but slightly lesser than urea within a wide temperature range (875 to 1125 deg. C). It was also observed that the NOx removal efficiency was increased with increasing the molar ratio. (author)

  8. NOx adsorber and method of regenerating same

    Science.gov (United States)

    Endicott, Dennis L.; Verkiel, Maarten; Driscoll, James J.

    2007-01-30

    New technologies, such as NOx adsorber catalytic converters, are being used to meet increasingly stringent regulations on undesirable emissions, including NOx emissions. NOx adsorbers must be periodically regenerated, which requires an increased fuel consumption. The present disclosure includes a method of regenerating a NOx adsorber within a NOx adsorber catalytic converter. At least one sensor positioned downstream from the NOx adsorber senses, in the downstream exhaust, at least one of NOx, nitrous oxide and ammonia concentrations a plurality of times during a regeneration phase. The sensor is in communication with an electronic control module that includes a regeneration monitoring algorithm operable to end the regeneration phase when a time rate of change of the at least one of NOx, nitrous oxide and ammonia concentrations is after an expected plateau region begins.

  9. Photo Catalytic Removal of Sodium Dodecyl Sulfate From Aquatic Solutions With Prepared ZnO Nanocrystals and UV Irradiation

    OpenAIRE

    Mohammad Taghi Samadi; Mir Saeid Sayed Dorraji; Zolykha Atashi; Ali Reza Rahmani

    2014-01-01

    In this study, ZnO Nano catalyst has been synthesized and examined as photo catalyst for UV-induced removal of Sodium Dodecyl Sulfate (SDS) from aquatic solutions. This anionic surfactant was selected based upon its toxicity, wide use in industrial laundry and as a primary pollutant in municipal waste water systems.This study aimed to investigate removal of surfactant, SDS, in a batch photo catalytic reactor under various operating conditions including ZnO suspension concentration, initial su...

  10. ACIDIC REMOVAL OF METALS FROM FLUIDIZED CATALYTIC CRACKING CATALYST WASTE ASSISTED BY ELECTROKINETIC TREATMENT

    Directory of Open Access Journals (Sweden)

    R. B. G. Valt

    2015-06-01

    Full Text Available AbstractOne of the main uses of catalysts in the oil industry is in the fluidized catalytic cracking process, which generates large quantities of waste material after use and regeneration cycles and that can be treated by the electrokinetic remediation technique, in which the contaminant metals are transported by migration. In this study, deactivated FCC catalyst was characterized before and after the electrokinetic remediation process to evaluate the amount of metal removed, and assess structural modifications, in order to indicate a possible use as an adsorbent material. The analyses included pH measurement and the concentration profile of vanadium ions along the reactor, X-ray microtomography, X-ray fluorescence, BET analysis and DTA analysis. The results indicated that 40% of the surface area of the material was recovered in relation to the disabled material, showing an increase in the available area for the adsorption. The remediation process removed nearly 31% of the vanadium and 72% of the P2O5 adhering to the surface of the catalyst, without causing structural or thermal stability changes.

  11. Evaluation of Performance Catalytic Ozonation Process with Activated Carbon in the Removal of Humic Acids from Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    Gh. Asgari

    2011-01-01

    Full Text Available Introduction & Objective: In recent years, the use of alternative disinfectants and the control of natural organic matters are two approaches that are typically applied in water treatment utilities to reduce the formation of chlorinated disinfection by-products. Catalytic ozonation is a new technology used to promote the efficiency of ozonation. The goal of this study was to survey the feasibility application of activated carbon as a catalyst in ozonation process for removal of humic acids from aqueous solution. Materials & Methods: This experimental study has been done in laboratory of water and wastewater chemistry, Tarbiat Modarres University. The solid structure and chemical composition of activated carbon were analyzed by X-ray fluorescence (XRF. Ozonation and catalytic ozonation experiments were performed in a semi-batch reactor and the mass of ozone produced was measured by iodometric titration methods. Concentration changes of humic acid in samples with a concentration of 15 mg/l were determined by using spectrophotometer at an absorbance wavelength of 254 nm. To evaluate the performance of catalytic ozonation in humic acid removal, total organic carbon and trihalomethane formation potential were evaluated and the results were analyzed by Excel software. Results: Catalytic ozone results showed that using activated carbon as a catalyst increased humic acid decomposition up to 11 times and removal efficiency increased with increasing pH (4-12 and catalyst dosage (0.25-1.5 g/250cc. The experimental results showed that catalytic ozonation was most effective in less time (10 min with considerable efficiency (95% compared to the sole ozonation process (SOP. Conclusion: The results indicated that the catalytic ozonation process, compared to SOP, was less affected by radical scavenger, and total organic carbon, and trihalomethane formation potential removal achieved were 30% and 83%, respectively. (Sci J Hamadan Univ Med Sci 2011;17(4:25-33

  12. Removal of NOx by combining TiO2 catalyst with DC corona discharge%用TiO2光催化剂与直流电晕放电结合去除NOx

    Institute of Scientific and Technical Information of China (English)

    宿鹏浩

    2011-01-01

    In order to remove Nox effectively, the DC corona discharge is combined with TiO2 catalyst which is prepared by micro-plasma-arc discharge to investigate the effects of electrode polarity and discharge power on removal efficiency of Nox, the denitrification mechanism is analyzed, and the energy efficiency of denitrification system is evaluated. Experimental result shows that the TiO2 catalyst exhibits significant photocatalytic effect when being combined with positive corona discharge, and the strength of photocatalytic effect is proportional to the discharge power. In the case of positive corona discharge combined with the TiO2 catalyst, and when the discharge power is enhanced, the removal efficiency is improved but there is no lose of energy efficiency.%为有效去除氮氧化物,将以微电弧放电法制备的TiO2光催化剂与直流电晕放电结合,考察放电极性、放电功率对脱硝效果的影响,分析脱硝机理,评价脱硝体系的能量效率.实验结果表明:TiO2光催化剂在正电晕放电显现出显著的光催化效应,光催化效应强弱与放电功率成正比;在TiO2光催化剂与直流电晕放电结合的情况下增大放电功率,可以提高脱硝效果,但是能量效率无损失.

  13. Low absorption vitreous carbon reactors for operando XAS: a case study on Cu/Zeolites for selective catalytic reduction of NO(x) by NH3.

    Science.gov (United States)

    Kispersky, Vincent F; Kropf, A Jeremy; Ribeiro, Fabio H; Miller, Jeffrey T

    2012-02-21

    We describe the use of vitreous carbon as an improved reactor material for an operando X-ray absorption spectroscopy (XAS) plug-flow reactor. These tubes significantly broaden the operating range for operando experiments. Using selective catalytic reduction (SCR) of NO(x) by NH(3) on Cu/Zeolites (SSZ-13, SAPO-34 and ZSM-5) as an example reaction, we illustrate the high-quality XAS data achievable with these reactors. The operando experiments showed that in Standard SCR conditions of 300 ppm NO, 300 ppm NH(3), 5% O(2), 5% H(2)O, 5% CO(2) and balance He at 200 °C, the Cu was a mixture of Cu(I) and Cu(II) oxidation states. XANES and EXAFS fitting found the percent of Cu(I) to be 15%, 45% and 65% for SSZ-13, SAPO-34 and ZSM-5, respectively. For Standard SCR, the catalytic rates per mole of Cu for Cu/SSZ-13 and Cu/SAPO-34 were about one third of the rate per mole of Cu on Cu/ZSM-5. Based on the apparent lack of correlation of rate with the presence of Cu(I), we propose that the reaction occurs via a redox cycle of Cu(I) and Cu(II). Cu(I) was not found in in situ SCR experiments on Cu/Zeolites under the same conditions, demonstrating a possible pitfall of in situ measurements. A Cu/SiO(2) catalyst, reduced in H(2) at 300 °C, was also used to demonstrate the reactor's operando capabilities using a bending magnet beamline. Analysis of the EXAFS data showed the Cu/SiO(2) catalyst to be in a partially reduced Cu metal-Cu(I) state. In addition to improvements in data quality, the reactors are superior in temperature, stability, strength and ease of use compared to previously proposed borosilicate glass, polyimide tubing, beryllium and capillary reactors. The solid carbon tubes are non-porous, machinable, can be operated at high pressure (tested at 25 bar), are inert, have high material purity and high X-ray transmittance.

  14. Low absorption vitreous carbon reactors for operando XAS: a case study on Cu/Zeolites for selective catalytic reduction of NO(x) by NH3.

    Science.gov (United States)

    Kispersky, Vincent F; Kropf, A Jeremy; Ribeiro, Fabio H; Miller, Jeffrey T

    2012-02-21

    We describe the use of vitreous carbon as an improved reactor material for an operando X-ray absorption spectroscopy (XAS) plug-flow reactor. These tubes significantly broaden the operating range for operando experiments. Using selective catalytic reduction (SCR) of NO(x) by NH(3) on Cu/Zeolites (SSZ-13, SAPO-34 and ZSM-5) as an example reaction, we illustrate the high-quality XAS data achievable with these reactors. The operando experiments showed that in Standard SCR conditions of 300 ppm NO, 300 ppm NH(3), 5% O(2), 5% H(2)O, 5% CO(2) and balance He at 200 °C, the Cu was a mixture of Cu(I) and Cu(II) oxidation states. XANES and EXAFS fitting found the percent of Cu(I) to be 15%, 45% and 65% for SSZ-13, SAPO-34 and ZSM-5, respectively. For Standard SCR, the catalytic rates per mole of Cu for Cu/SSZ-13 and Cu/SAPO-34 were about one third of the rate per mole of Cu on Cu/ZSM-5. Based on the apparent lack of correlation of rate with the presence of Cu(I), we propose that the reaction occurs via a redox cycle of Cu(I) and Cu(II). Cu(I) was not found in in situ SCR experiments on Cu/Zeolites under the same conditions, demonstrating a possible pitfall of in situ measurements. A Cu/SiO(2) catalyst, reduced in H(2) at 300 °C, was also used to demonstrate the reactor's operando capabilities using a bending magnet beamline. Analysis of the EXAFS data showed the Cu/SiO(2) catalyst to be in a partially reduced Cu metal-Cu(I) state. In addition to improvements in data quality, the reactors are superior in temperature, stability, strength and ease of use compared to previously proposed borosilicate glass, polyimide tubing, beryllium and capillary reactors. The solid carbon tubes are non-porous, machinable, can be operated at high pressure (tested at 25 bar), are inert, have high material purity and high X-ray transmittance. PMID:22158950

  15. The pilot plant experiment of electron beam irradiation process for removal of NOx and SOx from sinter plant exhaust gas in the iron and steel industry

    International Nuclear Information System (INIS)

    Air pollution problem has become more important in the progress of industry. Nitrogen oxides (NOx, mostly NO) and sulfur oxides (SOx, mostly SO2) which are contained in a sinter plant exhaust gas, are known as serious air pollutants. In such circumstances, an attempt has been made to simultaneously remove NOx and SOx from the sinter plant exhaust gas by means of a new electron beam irradiation process. The process consists of adding a small amount of NH3 to the exhaust gas, irradiating the gas by electron beam, forming ammonium salts by reactions of NOx and SOx with the NH3 and collecting ammonium salts by dry electrostatic precipitator (E.P.). Basic research on the present process had been performed using heavy oil combustion gas. Based on the results research was launched to study the applicability of the process to the treatment of sinter plant exhaust gas. A pilot plant, capable of treating a gas flow of 3000 Nm3/H was set up, and experiments were performed from July 1977 to June 1978. The plant is described and the results are presented. (author)

  16. Improvement of LSM15-CGO10 electrodes for electrochemical removal of NOx by KNO3 and MnOx impregnation

    DEFF Research Database (Denmark)

    Traulsen, Marie Lund; Kammer Hansen, Kent

    2011-01-01

    in 1000 ppm NO, 10% O2 and 1000 ppm NO + 10% O2 in the temperature range 300-500 °C and the electrodes were investigated by scanning electron microscopy before and after testing. At 400-450 °C a NOx-storage process was observed on the KNO3-impregnated electrodes, this process appeared to be dependent...

  17. Electrochemical reduction of NOx

    DEFF Research Database (Denmark)

    Traulsen, Marie Lund

    NO and NO2 (collectively referred to as NOx) are air pollutants, and the largest single contributor to NOx pollution is automotive exhaust. This study investigates electrochemical deNOx, a technology which aims to remove NOx from automotive diesel exhaust by electrochemical reduction of NOx to N2...... and O2. The focus in this study is on improving the activity and selectivity of solid oxide electrodes for electrochemical deNOx by addition of NOx storage compounds to the electrodes. Two different composite electrodes, La0.85Sr0.15MnO3-δ-Ce0.9Gd0.1O1.95 (LSM15-CGO10) and La0.85Sr0.15FeO3-δ-Ce0.9Gd0.1O......1.95 (LSF15-CGO10), have been investigated in combination with three different NOx storage compounds: BaO, K2O and MnOx. The main focus in the investigation has been on conversion measurements and electrochemical characterization, the latter by means of electrochemical impedance spectroscopy...

  18. DeNOx Study in Diesel Engine Exhaust Using Barrier Discharge Corona Assisted by V2O5/TiO2 Catalyst

    Institute of Scientific and Technical Information of China (English)

    B. S. Rajanikanth; V. Ravi

    2004-01-01

    A plasma-assisted catalytic reactor was used to remove nitrogen oxides (Nox) from diesel engine exhaust operated under different load conditions. Initial studies were focused on plasma reactor (a dielectric barrier discharge reactor) treatment of diesel exhaust at various temperatures. The nitric oxide (NO) removal efficiency was lowered when high temperature exhaust was treated using plasma reactor. Also, NO removal efficiency decreased when 45% load exhaust was treated. Studies were then made with plasma reactor combined with a catalytic reactor consisting of a selective catalytic reduction (SCR) catalyst, V2O5/TiO2. Ammonia was used as a reducing agent for SCR process in a ratio of 1:1 to Nox. The studies were focused on temperatures of the SCR catalytic reactor below 200 ℃. The plasma-assisted catalytic reactor was operated well to remove Nox under no-load and load conditions. For an energy input of 96 J/l, the Nox removal efficiencies obtained under no-load and load conditions were 90% and 72% respectively at an exhaust temperature of 100 ℃.

  19. DeNOx study in diesel engine exhaust using barrier discharge corona assisted by V2O5/TiO2 catalyst

    International Nuclear Information System (INIS)

    A plasma-assisted catalytic reactor was used to remove nitrogen oxides (NOx) from diesel engine exhaust operated under different load conditions. Initial studies were focused on plasma reactor (a dielectric barrier discharge reactor) treatment of diesel exhaust at various temperatures. The nitric oxide (NO) removal efficiency was lowered when high temperature exhaust was treated using plasma reactor. Also, NO removal efficiency decreased when 45% load exhaust was treated. Studies were then made with plasma reactor combined with a catalytic reactor consisting of a selective catalytic reduction (SCR) catalyst, V2O5/TiO2. Ammonia was used as a reducing agent for SCR process in a ratio of 1:1 to NOx. The studies were focused on temperatures of the SCR catalytic reactor below 200 degree C. The plasma-assisted catalytic reactor was operated well to remove NOx under no-load and load conditions. For an energy input of 96 J/1, the NOx removal efficiencies obtained under no-load and load conditions were 90% and 72% respectively at an exhaust temperature of 100 degree C. (authors)

  20. Molecular Simulation of Naphthenic Acid Removal on Acidic Catalyst Ⅱ. Experimental results of catalytic decarboxylation over acidic catalysts

    Institute of Scientific and Technical Information of China (English)

    Fu Xiaoqin; Tian Songbai; Hou Shuandi; Longjun; Wang Xieqing

    2008-01-01

    The energy barriers of thermal decarboxylation reactions of petroleum acids and catalytic decarboxylation reactions of Br(o)nsted acid and Lewis acid were analyzed using molecular simulation technology.Compared with thermal decarboxylation reactions of petroleum acids, the decarboxylation reactions by acid catalysts were easier to occur. The decarboxylaton effect by Lewis acid was better than Br(o)nsted acid. The mechanisms of catalytic decarboxylation over acid catalyst were also verified by experiments on a fixed bed and a fluidized bed, the experimental results showed that the rate of acid removal could reach up to 97% over the acidic catalyst at a temperature above 400℃.

  1. Recapitulation of the hairless mouse phenotype using catalytic oligonucleotides: implications for permanent hair removal.

    Science.gov (United States)

    Cserhalmi-Friedman, Peter B; Panteleyev, Andrey A; Christiano, Angela M

    2004-03-01

    Ribozyme technology is widely used to target mRNA in a sequence-specific fashion and thus change the expression pattern of cells or tissues. While the goal of mRNA targeting is usually the cleavage of mutant mRNAs with the prospect of gene therapy for inherited diseases, in certain instances, targeting of wild-type genes can be used therapeutically. Lack of expression of the mouse hairless gene due to inherited mutations leads to the complete and irreversible loss of hair known as atrichia. We designed this study to recapitulate the hairless phenotype in a restricted manner by topical application of deoxyribozyme-targeting molecules to specifically cleave the mouse hairless mRNA. Histological samples taken from treated skin at different times demonstrated a decreased number of hair follicles, an involution of the remaining follicles, a separation of the dermal papillae, and the presence of dermal cysts, all characteristics of the hairless phenotype, but not normally present in the skin of C57Bl/6 J mice. In this study, we successfully recapitulated the hairless phenotype using topically applied target-specific catalytic oligonucleotides designed to cleave the mouse hairless mRNA. Our results demonstrate the feasibility of using ribozyme technology to alter the gene expression in the skin via topical application and provide proof of principle for the development of this strategy for permanent hair removal.

  2. Combined removal of diesel soot particulates and NOx over CeO2–ZrO2 mixed oxides

    OpenAIRE

    Atribak, Idriss; Bueno López, Agustín; García García, Avelina

    2008-01-01

    CeO2 and Ce–Zr mixed oxides with different Ce:Zr ratios were prepared; characterised by Raman spectroscopy, XRD, TEM, N2 adsorption at −196 ◦C, and H2-TPR; and tested for soot oxidation under NOx/O2. Among the different mixed oxides, Ce0.76Zr0.24O2 provided the best results. Ce0.76Zr0.24O2 presented greater activity than pure CeO2 for soot oxidation by NOx/O2 when both catalysts were calcined at 500 ◦C (soot oxidation rates at 500 ◦C are 14.9 and 11.4 μgsoot/s, respectively), and ...

  3. Removal of nitrogen compounds from gasification gas by selective catalytic or non-catalytic oxidation; Typpiyhdisteiden poisto kaasutuskaasusta selektiivisellae katalyyttisellae ja ei-katalyyttisellae hapetuksella

    Energy Technology Data Exchange (ETDEWEB)

    Leppaelahti, J.; Koljonen, T. [VTT Energy, Espoo (Finland)

    1996-12-01

    In gasification reactive nitrogenous compounds are formed from fuel nitrogen, which may form nitrogen oxides in gas combustion. In fluidized bed gasification the most important nitrogenous compound is ammonia (NH{sub 3}). If ammonia could be decomposed to N{sub 2} already before combustion, the emissions if nitrogen oxides could be reduced significantly. One way of increasing the decomposition rate of NH{sub 3} could be the addition of suitable reactants to the gas, which would react with NH{sub 3} and produce N{sub 2}. The aim of this research is to create basic information, which can be used to develop a new method for removal of nitrogen compounds from gasification gas. The reactions of nitrogen compounds and added reactants are studied in reductive atmosphere in order to find conditions, in which nitrogen compounds can be oxidized selectively to N{sub 2}. The project consists of following subtasks: (1) Selective non-catalytic oxidation (SNCO): Reactions of nitrogen compounds and oxidizers in the gas phase, (2) Selective catalytic oxidation (SCO): Reactions of nitrogen compounds and oxidizers on catalytically active surfaces, (3) Kinetic modelling of experimental results in co-operation with the Combustion Chemistry Research Group of Aabo Akademi University. The most important finding has been that NH{sub 3} can be made to react selectively with the oxidizers even in the presence of large amounts of CO and H{sub 2}. Aluminium oxides were found to be the most effective materials promoting selectivity. (author)

  4. An Evaluation of the Vapor Phase Catalytic Ammonia Removal Process for Use in a Mars Transit Vehicle

    Science.gov (United States)

    Flynn, Michael; Borchers, Bruce

    1998-01-01

    An experimental program has been developed to evaluate the potential of the Vapor Phase Catalytic Ammonia Reduction (VPCAR) technology for use as a Mars Transit Vehicle water purification system. Design modifications which will be required to ensure proper operation of the VPCAR system in reduced gravity are also evaluated. The VPCAR system is an integrated wastewater treatment technology that combines a distillation process with high temperature catalytic oxidation. The distillation portion of the system utilizes a vapor compression distillation process to provide an energy efficient phase change separation. This portion of the system removes any inorganic salts and large molecular weight, organic contaminates, i.e., non-volatile, from the product water stream and concentrates these contaminates into a byproduct stream. To oxidize the volatile organic compounds and ammonia, a vapor phase, high temperature catalytic oxidizer is used. This catalytic system converts these compounds along with the aqueous product into CO2, H2O, and N2O. A secondary catalytic bed can then be used to reduce the N2O to nitrogen and oxygen (although not evaluated in this study). This paper describes the design specification of the VPCAR process, the relative benefits of its utilization in a Mars Transit Vehicle, and the design modification which will be required to ensure its proper operation in reduced gravity. In addition, the results of an experimental evaluation of the processors is presented. This evaluation presents the processors performance based upon product water purity, water recovery rates, and power.

  5. Simultaneous removal of NOX and SO2 from flue gases by energizing gases with electrons having energy in the range from 5 eV to 20 eV

    International Nuclear Information System (INIS)

    These notes report the results obtained with an experimental installation able to treat 100 Nm3/h of flue gases, installed at the Thermoelectrical Power Plant at Marghera. The experimental installation, operating on the principle of gas energizing, is able to remove simultaneously 40 to 50% of the NOX and about 100% of the SO2 contained in the flue gases. It is expected to achieve better efficiency in the removal of NOX by including in the system a bag filter which should favour removal reaction in the heterogeneous phase of NOX. Particulate concentration at output is between 2 and 5 mg/Nm3. A pulse generator designed and built by Enel was tested; the results were excellent, so work has begun on the preliminary planning of a 200 kW pulse generator that operates on the same principle. (author)

  6. Removal and Conversion of Tar in Syngas from Woody Biomass Gasification for Power Utilization Using Catalytic Hydrocracking

    OpenAIRE

    Jiu Huang; Klaus Gerhard Schmidt; Zhengfu Bian

    2011-01-01

    Biomass gasification has yet to obtain industrial acceptance. The high residual tar concentrations in syngas prevent any ambitious utilization. In this paper a novel gas purification technology based on catalytic hydrocracking is introduced, whereby most of the tarry components can be converted and removed. Pilot scale experiments were carried out with an updraft gasifier. The hydrocracking catalyst was palladium (Pd). The results show the dominant role of temperature and flow rate. At a cons...

  7. Photo Catalytic Removal of Sodium Dodecyl Sulfate From Aquatic Solutions With Prepared ZnO Nanocrystals and UV Irradiation

    Directory of Open Access Journals (Sweden)

    Mohammad Taghi Samadi

    2014-12-01

    Full Text Available In this study, ZnO Nano catalyst has been synthesized and examined as photo catalyst for UV-induced removal of Sodium Dodecyl Sulfate (SDS from aquatic solutions. This anionic surfactant was selected based upon its toxicity, wide use in industrial laundry and as a primary pollutant in municipal waste water systems.This study aimed to investigate removal of surfactant, SDS, in a batch photo catalytic reactor under various operating conditions including ZnO suspension concentration, initial surfactant concentration and initial pH of solution to find out the desired condition for removal of surfactant. ZnO Nano crystals were synthesized using the precipitation method and ZnSO4.7H2O was used as the starting material and NaOH as precipitant. The removal of SDS reactions by UV/ZnO process was performed into a batch photo reactor. In addition, various operating conditions including ZnO suspension concentration, initial surfactant concentration and initial pH of solution were investigated. In total, 98% of surfactant was removed at 40 minute and removal efficiency of SDS increased with increasing pH up to nine and after that with increase in pH, efficiency decreased. Possible roles of inorganic oxidant on the reaction were discussed. The removal of SDS follows pseudo-first order kinetics. Based on the results of this study, ZnO-UV photo catalytic process can be used as an efficient method for further study in detergents removal.

  8. Removal of Disinfection By-Products from Contaminated Water Using a Synthetic Goethite Catalyst via Catalytic Ozonation and a Biofiltration System

    Directory of Open Access Journals (Sweden)

    Yu-Hsiang Wang

    2014-09-01

    Full Text Available The effects of synthetic goethite (α-FeOOH used as the catalyst in catalytic ozonation for the degradation of disinfection by-product (DBP precursors are investigated. A biofiltration column applied following the catalytic ozonation process is used to evaluate the efficiency of removing DBP precursors via biotreatment. Ozone can rapidly react with aromatic compounds and oxidize organic compounds, resulting in a decrease in the fluorescence intensity of dissolved organic matter (DOM. In addition, catalytic ozonation can break down large organic molecules, which causes a blue shift in the emission-excitation matrix spectra. Water treated with catalytic ozonation is composed of low-molecular structures, including soluble microbial products (SMPs and other aromatic proteins (APs. The DOM in SMPs and APs is removed by subsequent biofiltration. Catalytic ozonation has a higher removal efficiency for dissolved organic carbon and higher ultraviolet absorbance at 254 nm compared to those of ozonation without a catalyst. The use of catalytic ozonation and subsequent biofiltration leads to a lower DBP formation potential during chlorination compared to that obtained using ozonation and catalytic ozonation alone. Regarding DBP species during chlorination, the bromine incorporation factor (BIF of trihalomethanes and haloacetic acids increases with increasing catalyst dosage in catalytic ozonation. Moreover, the highest BIF is obtained for catalytic ozonation and subsequent biofiltration.

  9. Selective catalytic reduction of NOx from exhaust of lean-burn engine over Ag-Al2O3/cordierite catalyst

    Institute of Scientific and Technical Information of China (English)

    LI Junhua; KANG Shoufang; FU Lixin; HAO Jiming

    2007-01-01

    A highly effective Ag-Al2O3 catalyst was prepared using the in-situ sol-gel method,and characterized by surface area using nitrogen adsorption,scanning electron microscopy(SEM),and transmission electron microscopy(TEM)techniques.The catalyst performance was tested on a real lean-burn gasoline engine.Only unburned hydrocarbons and carbon monoxide in the exhaust were directly used as reductant(without any external reductant),the maximum NOx conversion could only reach 40% at 450℃.When an external reductant,ethanol was added,the average NOx conversion was greater than 60%.At exhaust gas temperature range of 350-500℃.the maximum NOx conversion reached about 90%.CO and HC could be efficiently oxidized with Pt-AlO3 oxidation catalyst placed at the end of SCR converter.However,NOx conversion drastically decreased because of the oxidation of some intermediates to NOx again.The possible reaction mechanism was proposed as two typical processes,nitration,and reduction in HC-SCR over Ag-Al2O3.

  10. 氮氧化物(NOx)脱除技术的研究进展%Research Progress of Removal Technology of NOx

    Institute of Scientific and Technical Information of China (English)

    黄蓓; 许芳

    2014-01-01

    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。%Nitrogen oxide is one of the main pollutants in the ambient air .In this paper,the source and mechanism of nitrogen oxide and the damage of nitrogen oxide are introduced .Meanwhile , the removal technology of nitorgen oxide from the flue gas are summarized .

  11. Toluene removal from waste air stream by the catalytic ozonation process with MgO/GAC composite as catalyst.

    Science.gov (United States)

    Rezaei, Fatemeh; Moussavi, Gholamreza; Bakhtiari, Alireza Riyahi; Yamini, Yadollah

    2016-04-01

    This paper investigates the catalytic potential of MgO/GAC composite for toluene elimination from waste air in the catalytic ozonation process (COP). The MgO/GAC composite was a micro-porous material with the BET surface area of 1082m(2)/g. Different functional groups including aromatic CC, saturated CO of anhydrates, hydroxyl groups and SH bond of thiols were identified on the surface of MgO/GAC. Effects of residence time (0.5-4s), inlet toluene concentration (100-400ppmv) and bed temperature (25-100°C) were investigated on degradation of toluene in COP. Impregnation of GAC with MgO increased the breakthrough time and removal capacity by 73.9% and 64.6%, respectively, at the optimal conditions. The catalytic potential of the GAC and MgO/GAC for toluene degradation was 11.1% and 90.6%, respectively, at the optimum condition. The highest removal capacity using MgO/GAC (297.9gtoulene/gMgO/GAC) was attained at 100°C, whereas the highest removal capacity of GAC (128.5mgtoulene/gGAC) was obtained at 25°C. Major by-products of the toluene removal in COP with GAC were Formic acid, benzaldehyde, O-nitro-p-cresol and methyl di-phenyl-methane. MgO/GAC could greatly catalyze the decomposition of toluene in COPand formic acid was the main compound desorbed from the catalyst. Accordingly, the MgO/GAC is an efficient material to catalyze the ozonation of hydrocarbon vapors. PMID:26784452

  12. Removal of ammonia from aqueous solutions by catalytic oxidation with copper-based rare earth composite metal materials: catalytic performance, characterization, and cytotoxicity evaluation

    Institute of Scientific and Technical Information of China (English)

    Chang-Mao Hung

    2011-01-01

    Ammonia (NH3) has an important use in the chemical industry and is widely found in industrial wastewater.For this investigation of copper-based rare earth composite metal materials,aqueous solutions containing 400 mg/L of ammonia were oxidized in a batch-bed reactor with a catalyst prepared by the co-precipitation of copper nitrate,lanthanum nitrate and cerium nitrate.Barely any of the dissolved ammonia was removed by wet oxidation without a catalyst,but about 88% of the ammonia was reduced during wet oxidation over the catalysts at 423 K with an oxygen partial pressure of 4.0 MPa.The catalytic redox behavior was determined by cyclic voltammetry (CV).Furthermore,the catalysts were characterized using thermogravimetric analyzer (TGA) and scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDX),which showed that the catalytic behavior was related to the metal oxide properties of the catalyst.In addition,the copper-lanthanum-cerium composite-induced cytotoxicity in the human lung MRC-5 cell line was tested,and the percentage cell survival was determined by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetra-zolium (MTS) analysis in vitro.No apparent cytotoxicity was observed when the human lung cells were exposed to the copper-lanthanum-cerium composite.

  13. Selective catalytic reduction of nitrogen oxides with ammonia over microporous zeolite catalysts

    OpenAIRE

    VENNESTROM, PETER NICOLAI RAVNBORG

    2014-01-01

    With increasing legislative demands to remove nitrogen oxides (NOx) from automotive diesel exhaust, new catalyst systems are investigated and intensely studied in industry as well in academia. The most prevailing catalytic method of choice is the selective catalytic reduction (SCR) where non-toxic urea is used as a reductant for practical reasons. Usually urea is stored in a separate tank and once injected into the exhaust system it hydrolyses into the more aggressive reductant NH3 and CO2. ...

  14. SOx-NOx-Rox Box trademark demonstration project review

    International Nuclear Information System (INIS)

    The SOx-NOx-Rox Box trademark (SNRB trademark) process is a combined SOx, NOx and particulate (Rox) emission control technology developed by Babcock ampersand Wilcox in which high removal efficiencies for all three pollutants are achieved in a high-temperature baghouse. A 5-MWe equivalent demonstration of the technology cosponsored by the U.S. Department of Energy, the Ohio Department of Development/Ohio Coal Development Office and the Electric Power Research Institute has recently been completed at the Ohio Edison R.E. Burger Plant. SNRB incorporates dry sorbent injection for SOx emission control, selective catalytic reduction (SCR) for reducing NOx emissions, and a pulse-jet baghouse operating at 450 to 850 degrees F for controlling particulate emissions. The unique, high-temperature baghouse/catalyst configuration provides for integrated particulate capture, SO2 removal, and NOx reduction as well as the potential for reducing emissions of selected air toxics. The simultaneous, multiple emission control performance of SNRB is summarized using operating data generated in over 2,000 hours, of operation at the demonstration site

  15. Gas cleaning and hydrogen sulfide removal for COREX coal gas by sorption enhanced catalytic oxidation over recyclable activated carbon desulfurizer.

    Science.gov (United States)

    Sun, Tonghua; Shen, Yafei; Jia, Jinping

    2014-02-18

    This paper proposes a novel self-developed JTS-01 desulfurizer and JZC-80 alkaline adsorbent for H2S removal and gas cleaning of the COREX coal gas in small-scale and commercial desulfurizing devices. JTS-01 desulfurizer was loaded with metal oxide (i.e., ferric oxides) catalysts on the surface of activated carbons (AC), and the catalyst capacity was improved dramatically by means of ultrasonically assisted impregnation. Consequently, the sulfur saturation capacity and sulfur capacity breakthrough increased by 30.3% and 27.9%, respectively. The whole desulfurizing process combined selective adsorption with catalytic oxidation. Moreover, JZC-80 adsorbent can effectively remove impurities such as HCl, HF, HCN, and ash in the COREX coal gas, stabilizing the system pressure drop. The JTS-01 desulfurizer and JZC-80 adsorbent have been successfully applied for the COREX coal gas cleaning in the commercial plant at Baosteel, Shanghai. The sulfur capacity of JTS-01 desulfurizer can reach more than 50% in industrial applications. Compared with the conventional dry desulfurization process, the modified AC desulfurizers have more merit, especially in terms of the JTS-01 desulfurizer with higher sulfur capacity and low pressure drop. Thus, this sorption enhanced catalytic desulfurization has promising prospects for H2S removal and other gas cleaning. PMID:24456468

  16. Gas cleaning and hydrogen sulfide removal for COREX coal gas by sorption enhanced catalytic oxidation over recyclable activated carbon desulfurizer.

    Science.gov (United States)

    Sun, Tonghua; Shen, Yafei; Jia, Jinping

    2014-02-18

    This paper proposes a novel self-developed JTS-01 desulfurizer and JZC-80 alkaline adsorbent for H2S removal and gas cleaning of the COREX coal gas in small-scale and commercial desulfurizing devices. JTS-01 desulfurizer was loaded with metal oxide (i.e., ferric oxides) catalysts on the surface of activated carbons (AC), and the catalyst capacity was improved dramatically by means of ultrasonically assisted impregnation. Consequently, the sulfur saturation capacity and sulfur capacity breakthrough increased by 30.3% and 27.9%, respectively. The whole desulfurizing process combined selective adsorption with catalytic oxidation. Moreover, JZC-80 adsorbent can effectively remove impurities such as HCl, HF, HCN, and ash in the COREX coal gas, stabilizing the system pressure drop. The JTS-01 desulfurizer and JZC-80 adsorbent have been successfully applied for the COREX coal gas cleaning in the commercial plant at Baosteel, Shanghai. The sulfur capacity of JTS-01 desulfurizer can reach more than 50% in industrial applications. Compared with the conventional dry desulfurization process, the modified AC desulfurizers have more merit, especially in terms of the JTS-01 desulfurizer with higher sulfur capacity and low pressure drop. Thus, this sorption enhanced catalytic desulfurization has promising prospects for H2S removal and other gas cleaning.

  17. Fe-Mo/ZSM-5蜂窝催化剂上NOx的催化还原性能%STUDY ON CATALYTIC REDUCTION OF NOx PERFORMANCE OF HONEYCOMB Fe-Mo/ZSM-5 CATALYST

    Institute of Scientific and Technical Information of China (English)

    常立亚; 何凯; 王婧; 黄伟; 李哲

    2011-01-01

    Fe-Mo/ZSM-5 has a good NOx catalytic activity. In this basis, we compared the preparation methods of catalyst powder, catalyst additives, carriers and other factors on the honeycomb catalyst reduction. The results show that the catalytic activity prepared monolithic catalysts by gas phase ion exchange method is the best, at 350℃, the catalytic activity can be reach more than 90%. In high temperature(350℃-600℃ ) catalytic activity remained at 100%.The addition of K+ catalyst additives help increase powder catalytic activity. Powder catalyst impregnated on the carrier and roasting 2 times is the best.%Fe-Mo/ZSM-5具有较好的NOx催化活性,比较了不同粉末的制备方法、催化剂助剂和载体等因素对蜂窝状催化剂催化还原性能的影响.结果表明,气相离子交换法制备的蜂窝状催化剂的催化活性最好,在350℃时NOx转化率已达到90%以上,在高温400℃~600℃范围,催化剂对NOx的催化还原转化率保持在98%.K+离子的加入明显提高了Fe-Mo/ZSM-5催化剂活性,可能调变了催化剂的表面性质,催化剂粉末在载体上的浸涂次数为2次时效果最佳.

  18. Physico-Chemical Property and Catalytic Activity of a CeO2-Doped MnO(x)-TiO2 Catalyst with SO2 Resistance for Low-Temperature NH3-SCR of NO(x).

    Science.gov (United States)

    Shin, Byeongkil; Chun, Ho Hwan; Cha, Jin-Sun; Shin, Min-Chul; Lee, Heesoo

    2016-05-01

    The effects of CeO2 addition on the catalytic activity and the SO2 resistance of CeO2-doped MnO(x)-TiO2 catalysts were investigated for the low-temperature selective catalytic reduction (SCR) with NH3 of NO(x) emissions in marine applications. The most active catalyst was obtained from 30 wt% CeO2-MnO(x)-TiO2 catalyst in the whole temperature range of 100-300 degrees C at a low gas hourly space velocity (GHSV) of 10,000 h(-)1, and its de-NO(x) efficiency was higher than 90% over 250 degrees C. The enhanced catalytic activity may contribute to the dispersion state and catalytic acidity on the catalyst surface, and the highly dispersed Mn and Ce on the nano-scaled TiO2 catalyst affects the increase of Lewis and Brønsted acid sites. A CeO2-rich additive on MnO(x)-TiO2 could provide stronger catalytic acid sites, associated with NH3 adsorption and the SCR performance. As the results of sulfur resistance in flue gas that contains SO2, the de-NO(x) efficiency of MnO(x)-TiO2 decreased by 15% over 200 degrees C, whereas that of 30 wt% ceria-doped catalyst increased by 14-21% over 150 degrees C. The high SO2 resistance of CeO2-MnO(x)-TiO2 catalysts that resulted from the addition of ceria suppressed the formation of Mn sulfate species, which led to deactivation on the surface of nano-catalyst. PMID:27483759

  19. Physico-Chemical Property and Catalytic Activity of a CeO2-Doped MnO(x)-TiO2 Catalyst with SO2 Resistance for Low-Temperature NH3-SCR of NO(x).

    Science.gov (United States)

    Shin, Byeongkil; Chun, Ho Hwan; Cha, Jin-Sun; Shin, Min-Chul; Lee, Heesoo

    2016-05-01

    The effects of CeO2 addition on the catalytic activity and the SO2 resistance of CeO2-doped MnO(x)-TiO2 catalysts were investigated for the low-temperature selective catalytic reduction (SCR) with NH3 of NO(x) emissions in marine applications. The most active catalyst was obtained from 30 wt% CeO2-MnO(x)-TiO2 catalyst in the whole temperature range of 100-300 degrees C at a low gas hourly space velocity (GHSV) of 10,000 h(-)1, and its de-NO(x) efficiency was higher than 90% over 250 degrees C. The enhanced catalytic activity may contribute to the dispersion state and catalytic acidity on the catalyst surface, and the highly dispersed Mn and Ce on the nano-scaled TiO2 catalyst affects the increase of Lewis and Brønsted acid sites. A CeO2-rich additive on MnO(x)-TiO2 could provide stronger catalytic acid sites, associated with NH3 adsorption and the SCR performance. As the results of sulfur resistance in flue gas that contains SO2, the de-NO(x) efficiency of MnO(x)-TiO2 decreased by 15% over 200 degrees C, whereas that of 30 wt% ceria-doped catalyst increased by 14-21% over 150 degrees C. The high SO2 resistance of CeO2-MnO(x)-TiO2 catalysts that resulted from the addition of ceria suppressed the formation of Mn sulfate species, which led to deactivation on the surface of nano-catalyst.

  20. Performance of V2O5-WO3-MoO3/TiO2 Catalyst for Selective Catalytic Reduction of NOx by NH3

    Institute of Scientific and Technical Information of China (English)

    GAO Yan; LUAN Tao; L(U) Tao; CHENG Kai; XU Hongming

    2013-01-01

    The V2O5-WO3-MoO3/TiO2 honeycomb catalyst was prepared with industrial grade chemicals.The structural and physico-chemical properties were analyzed with X-ray diffraction (XRD),scanning electron micrograph (SEM) and mercury porosimetry.The NOx conversion and durability were investigated on a pilot plant test set under the actual operational conditions of a coal fired boiler.The catalyst monolith had good formability with mass percentage ofV: W: Mo: TiO2: fiber glass=1: 4.5: 4.5: 72: 18.Vanadium,tungsten and molybdenum species were highly dispersed on anatase TiO2 without causing the transformation of anatase TiO2 to rutile by calcining under a current of air at 450 ℃ for 4.5 h,but there were some degrees of crystal distortion.The catalyst particle sizes were almost uniform with close pile-up and the pore structure was regular with complete macro-pore formation and large specific surface area.The NOx conversion was sensitive to temperature but nearly insensitive to NH3.The catalyst showed strong adaptability to NOx concentration with activity above 80% in the range of 615-1640 mg·m-3.Within the range of 720-8640 h continuous operation,the NOx conversion dropped at a rate of about 1% reduction per 600 h.

  1. DEVELOPMENT OF MULTI-TASK CATALYSTS FOR REMOVAL OF NOx AND TOXIC ORGANIC COMPOUNDS DURING COAL COMBUSTION

    Energy Technology Data Exchange (ETDEWEB)

    Panagiotis G. Smirniotis; Robert G. Jenkins

    2002-02-04

    The work performed during this project focused on the identification of materials capable of providing high activity and selectivity for the selective catalytic reduction of nitric oxide with ammonia. The material surface characteristics were correlated with the catalytic behavior of our catalysts to increase our understanding and to help improve the DeNO{sub x} efficiency. The catalysts employed in this study include mixed oxide composite powders (TiO{sub 2}-Cr{sub 2}O{sub 3}, TiO{sub 2}-ZrO{sub 2}, TiO{sub 2}-WO{sub 3}, TiO{sub 2}-SiO{sub 2}, and TiO{sub 2}-Al{sub 2}O{sub 3}) loaded with varying amounts of V{sub 2}O{sub 5}, along with 5 different commercial sources of TiO{sub 2}. V{sub 2}O{sub 5} was added to the commercial sources of TiO{sub 2} to achieve monolayer coverage. Since the valence state of vanadium in the precursor solution during the impregnation step significantly impacted catalytic performance, catalysts were synthesized from both V{sup +4} and V{sup +5} solutions explain this phenomenon. Specifically, the synthesis of catalysts from V{sup 5+} precursor solutions yields lower-performance catalysts compared to the case of V{sup 4+} under identical conditions. Aging the vanadium precursor solution, which is associated with the reduction of V{sup 5+} to V{sup 4+} (VO{sub 2}{sup +} {yields} VO{sup 2+}), prior to impregnation results in catalysts with excellent catalytic behavior under identical activation and operating conditions. This work also added vanadia to TiO{sub 2}-based supports with low crystallinity. These supports, which have traditionally performed poorly, are now able to function as effective SCR catalysts. Increasing the acidity of the support by incorporating oxides such as WO{sub 3} and Al{sub 2}O{sub 3} significantly improves the SCR activity and nitrogen selectivity. It was also found that the supports should be synthesized with the simultaneous precipitation of the corresponding precursors. The mixed oxide catalysts possess

  2. Urea thermolysis and NOx reduction with and without SCR catalysts

    International Nuclear Information System (INIS)

    Urea-selective catalytic reduction (SCR) has been a leading contender for removal of nitrogen oxides (deNOx) from diesel engine emissions. Despite its advantages, the SCR technology faces some critical detriments to its catalytic performance such as catalyst surface passivation (caused by deposit formation) and consequent stoichiometric imbalance of the urea consumption. Deposit formation deactivates catalytic performance by not only consuming part of the ammonia produced during urea decomposition but also degrading the structural and thermal properties of the catalyst surface. We have characterized the urea thermolysis with and without the urea-SCR catalyst using both spectroscopic (DRIFTS and Raman) and thermal techniques (thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC)) to identify the deposit components and their corresponding thermal properties. Urea thermolysis exhibits two decomposition stages, involving ammonia generation and consumption, respectively. The decomposition after the second stage leads to the product of melamine complexes, (HNC=NH)x(HNCO)y, that hinder catalytic performance. The presence of catalyst accompanied with a good spray of the urea solution helps to eliminate the second stage. In this work, kinetics of the direct reduction of NOx by urea is determined and the possibility of using additives to the urea solution in order to rejuvenate the catalyst surface and improve its performance will be discussed

  3. Excellent performance of one-pot synthesized Cu-SSZ-13 catalyst for the selective catalytic reduction of NOx with NH3.

    Science.gov (United States)

    Xie, Lijuan; Liu, Fudong; Ren, Limin; Shi, Xiaoyan; Xiao, Feng-Shou; He, Hong

    2014-01-01

    Cu-SSZ-13 samples prepared by a novel one-pot synthesis method achieved excellent NH3-SCR performance and high N2 selectivity from 150 to 550 °C after ion exchange treatments. The selected Cu3.8-SSZ-13 catalyst was highly resistant to large space velocity (800 000 h(-1)) and also maintained high NOx conversion in the presence of CO2, H2O, and C3H6 in the simulated diesel exhaust. Isolated Cu(2+) ions located in three different sites were responsible for its excellent NH3-SCR activity. Primary results suggest that the one-pot synthesized Cu-SSZ-13 catalyst is a promising candidate as an NH3-SCR catalyst for the NOx abatement from diesel vehicles. PMID:24295053

  4. Removal of ammonia from producer gas in biomass gasification: integration of gasification optimisation and hot catalytic gas cleaning

    Energy Technology Data Exchange (ETDEWEB)

    Hongrapipat, Janjira; Saw, Woei-Lean; Pang, Shusheng [University of Canterbury, Department of Chemical and Process Engineering, Christchurch (New Zealand)

    2012-12-15

    Ammonia (NH{sub 3}) is one of the main contaminants in the biomass gasification producer gas, which is undesirable in downstream applications, and thus must be removed. When the producer gas is used in integrated gasification combined cycle (IGCC) technology, NH{sub 3} is the main precursor of nitrogen oxides (NO{sub x}) formed in gas turbine, whereas in Fischer-Tropsch synthesis and in integrated gasification fuel cell (IGFC) technology, the NH{sub 3} gas poisons the catalysts employed. This paper presents a critical review on the recent development in the understanding of the NH{sub 3} formation in biomass gasification process and in the NH{sub 3} gas cleaning technologies. The NH{sub 3} gas concentration in the producer gas can firstly be reduced by the primary measures taken in the gasification process by operation optimisation and using in-bed catalytic materials. Further removal of the NH{sub 3} gas can be implemented by the secondary measures introduced in the post-gasification gas-cleaning process. Focus is given on the catalytic gas cleaning in the secondary measures and its advantages are analysed including energy efficiency, impacts on environment and recyclability of the catalyst. Based on the review, the most effective cleaning process is proposed with integration of both the primary and the secondary measures for application in a biomass gasification process. (orig.)

  5. A Broad Spectrum Catalytic System for Removal of Toxic Organics from Water by Deep Oxidation - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Sen, Ayusman

    2000-12-01

    A most pressing need for the DOE environmental management program is the removal of toxic organic compounds present in groundwater and soil at specific DOE sites. While several remediation procedures have been proposed, they suffer from one or more drawbacks. The objective of the present research was to develop new catalytic procedures for the removal of toxic organic compounds from the environment through their deep oxidation to harmless products. In water, metallic palladium was found to catalyze the deep oxidation of a wide variety of toxic organic compounds by dioxygen at 80-90 C in the presence of carbon monoxide or dihydrogen. Several classes of organic compounds were examined: benzene, phenol and substituted phenols, nitro and halo organics, organophosphorus, and organosulfur compounds. In every case, deep oxidation to carbon monoxide, carbon dioxide, and water occurred in high yields, resulting in up to several hundred turnovers over a 24 hour period. For substrates susceptible to hydrogenation, the conversions were generally high with dihydrogen than with carbon monoxide. It is clear from the results obtained that we have discovered an exceptionally versatile catalytic system for the deep oxidation of toxic organic compounds in water. This system possesses several attractive features not found simultaneously in other reported systems. These are (a) the ability to directly utilize dioxygen as the oxidant, (b) the ability to carry out the deep oxidation of a particularly wide range of functional organics, and (c) the ease of recovery of the catalyst by simple filtration.

  6. Research advance in non-thermal plasma induced selective catalytic reduction NOx with low hydrocarbon compounds%低温等离子体诱导低碳烃选择性催化还原NOx研究进展

    Institute of Scientific and Technical Information of China (English)

    苏清发; 刘亚敏; 陈杰; 潘华; 施耀

    2009-01-01

    The emission of nitrogen oxides (NOx) from stationary sources, primarily from power stations, industrial heaters and cogeneration plants, represents a major environmental problem. This paper intends to give a general review over the advances in non-thermal plasma assisted selective catalytic reduction (SCR) of NOx with lower hydrocarbon compounds. In the last decade, the non-thermal plasma induced SCR of nitrogen oxide with low hydrocarbon compounds has received much attention. The different hydrocarbons (≤C3) used in the research are discussed. As we know,methane is more difficultly activated than non-methane hydrocarbons, such as ethylene and propylene etc. The reduction mechanism is also discussed. In addition, aiming at the difficulties existed, the direction for future research is prospected.%综述了近年来低温等离子体诱导低碳烃选择性催化还原NOx的研究进展,详细介绍了难活化的甲烷及较易活化的非甲烷低碳烃气体如乙烯、丙烯及丙烷等的研究现状,探讨了低温等离子体诱导低碳烃选择性催化还原NOx的反应机理,并展望了低温等离子体诱导低碳烃选择性催化还原NOx今后研究方向.

  7. Orange II removal by catalytic wet peroxide oxidation using activated carbon xerogels

    OpenAIRE

    Pinho, Maria; Silva, Adrián; Fathy, Nady; Attia, Amina; Gomes, Helder; Faria, Joaquim

    2013-01-01

    Orange II is a synthetic dye widely employed in the textile industry and responsible for serious environrnentaI cancerns. Dyes like this urge the development af new technologies for the treatment af wastewaters generated in this industrial activity. Those include catalytic wet peroxide oxidation (CWPO), which is an advanced oxidation process (AOP) based on the generation of hydroxyl radicais (I-lO·) from hydrogen peroxide with tlle aid ofa suitable catalysl [I].

  8. Catalytic reduction of NH4NO3 by NO. Effects of solid acids and implications for low temperature DeNOx processes

    International Nuclear Information System (INIS)

    Ammonium nitrate is thermally stable below 250 C and could potentially deactivate low temperature NOx reduction catalysts by blocking active sites. It is shown that NO reduces neat NH4NO3 above its 170 C melting point, while acidic solids catalyze this reaction even at temperatures below 100 C. NO2, a product of the reduction, can dimerize and then dissociate in molten NH4NO3 to NO+ + NO3-, and may be stabilized within the melt as either an adduct or as HNO2 formed from the hydrolysis of NO+ or N2O4. The other product of reduction, NH4NO2, readily decomposes at ≤100 C to N2 and H2O, the desired end products of DeNOx catalysis. A mechanism for the acid catalyzed reduction of NH4NO3 by NO is proposed, with HNO3 as an intermediate. These findings indicate that the use of acidic catalysts or promoters in DeNOx systems could help mitigate catalyst deactivation at low operating temperatures (<150 C). (author)

  9. Simultaneous removal of methylene blue and copper(II) ions by photoelectron catalytic oxidation using stannic oxide modified iron(III) oxide composite electrodes

    International Nuclear Information System (INIS)

    Highlights: • Photoelectron catalytic oxidation was used for methylene blue and Cu2+ removal. • SnO2/Fe2O3 was prepared and characterized for use as photoanodes and photocathodes. • Optimal reaction conditions were determined for methylene blue and Cu2+ removal. • Methylene blue removal followed the Langmuir–Freundlich–Hinshelwood kinetic model. • Cu2+ removal followed the first-order rate model. - Abstract: Stannic oxide modified Fe(III) oxide composite electrodes (SnO2/Fe2O3) were synthesized for simultaneously removing methylene blue (MB) and Cu(II) from wastewater using photoelectron catalytic oxidation (PEO). The SnO2/Fe2O3 electrodes were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and photoelectrochemical techniques. The removal of MB and Cu(II) by PEO using the SnO2/Fe2O3 composite electrodes was studied in terms of reaction time, electric current density, and pH of the electrolyte. The kinetics of the reactions were investigated using batch assays. The optimal reaction time, pH, and electric current density of the PEO process were determined to be 30 min, 6.0, and 10 mA/cm2, respectively. The removal rates of MB from wastewater treated by PEO and electron catalytic oxidation process were 84.87% and 70.64%, respectively, while the recovery rates of Cu(II) were 91.75% and 96.78%, respectively. The results suggest that PEO is an effective method for the simultaneous removal of MB and Cu(II) from wastewater, and the PEO process exhibits a much higher removal rate for MB and Cu(II) compared to the electron catalytic oxidation process. Furthermore, the removal of MB was found to follow the Langmuir–Freundlich–Hinshelwood kinetic model, whereas the removal of Cu(II) fitted well to the first-order reaction model

  10. NH3选择性还原NOx技术在重型柴油车尾气净化中的应用%Selective catalytic reduction of NOx by NH3 for heavy-duty diesel vehicles

    Institute of Scientific and Technical Information of China (English)

    刘福东; 单文坡; 潘大伟; 李腾英; 贺泓

    2014-01-01

    基于实验室对柴油车用V2O5-WO3/TiO2催化剂配方以及涂覆成型技术的大量研究,设计了一条产量为6000只/月的NH3选择性催化还原NOx (NH3-SCR)催化剂中试生产线,并对生产的催化剂产品进行了发动机台架测试。结果表明,实验室制备的V2O5-WO3/TiO2粉体催化剂和生产线产品,在空速为50000 h-1和200-450°C条件下NOx转化率均可达80%以上;采用大尺寸堇青石载体涂覆后制备的V2O5-WO3/TiO2整体催化剂经实验室小样测试,在空速为10000-30000 h-1和250-450°C条件下NOx转化率也为80%以上。发动机台架测试结果表明,该催化剂产品可使重型柴油机NOx排放达到国IV标准中欧洲稳态循环(ESC)和欧洲瞬态循环(ETC)排放限值的要求。该生产线经适当调整后也可用于生产非钒基NH3-SCR整体催化剂,以满足未来钒基NH3-SCR催化剂更新换代的需求。%A catalyst production line with a production capacity of 6000 catalyst monoliths per month for the selective catalytic reduction of NOx by NH3 (NH3-SCR) for NOx abatement in diesel vehicle exhaust was set up based on a detailed laboratory study of the catalyst formulation and washcoating tech-nology for V2O5-WO3/TiO2 catalyst. The catalyst produced by this line was tested on a bench scale diesel engine. The V2O5-WO3/TiO2 powder catalyst prepared in the laboratory and production line both achieved>80%NOx conversion at 200-450 °C and a GHSV of 50000 h-1. The washcoated cata-lyst used a large cordierite support and gave>80%NOx conversion at 250-450 °C and GHSVs of 10000-30000 h-1. The engine bench tests showed that after treatment by the catalyst, the NOx emis-sion met the European steady-state cycle (ESC) and European transient cycle (ETC) limits of the China IV standard. The production line can also be used for the production of vanadium-free NH3-SCR catalysts to meet the required replacement of the present vanadium-based NH3-SCR cata-lyst in the future.

  11. Study of the Effect of Preparation Method on the Catalytic Reduction of NOx over Fe-Mn/ZSM-5/CC%制备方法对Fe-Mn/ZSM-5/CC催化还原NOx性能的影响

    Institute of Scientific and Technical Information of China (English)

    郭玉玉; 张申; 刘鹏飞; 李哲

    2015-01-01

    Solution impregnation ,slurry dip coating and ultrasonic assisted dip coating were a‐dopted to prepare three kinds of Fe‐Mn/ZSM‐5/CC (CC :cordierite) monolithic catalysts .Their performance in catalytic reduction of NO x was studied .N2 adsorption and desorption ,XRD and SEM were used to explore the structure and properties of the catalysts .The results show that the catalyst preparation methods had significant impact on the performance of Fe‐M n/ZSM‐5/CC monolithic catalysts in catalytic reduction of NO x .The catalyst produced by ultrasonic assisted dip coating showed the best catalytic performance when compared with those prepared by solution impregnation or slurry dip coating .The reason was explained by its larger specific surface area , more uniform coatings and mesoporous structure .Its conversion rate was above 90% in the tem‐perature range of 180~430 ℃ .%采用溶液浸渍法、浆液浸涂法和超声波辅助浸涂法制备了3种Fe‐Mn/ZSM‐5/CC(CC即堇青石)整体式催化剂,研究了其催化还原 NOx 的性能。利用 N2吸附脱附、XRD、扫描电镜等技术对催化剂结构和性质进行探究。结果表明,制备方法对Fe‐M n/ZSM‐5/CC整体式催化剂催化还原NOx 性能有明显的影响,与溶液浸渍法和浆液浸涂法相比,超声波辅助浸涂法制备的催化剂具有较大的比表面积、较均匀的涂层以及较多的介孔结构,使其显示出最佳的催化性能,在180~430℃的温度范围内其转化率都在90%以上。

  12. Adsorptive removal of lead and cadmium ions using Cross -linked CMC Schiff base: Isotherm, Kinetics and Catalytic Activity

    Directory of Open Access Journals (Sweden)

    P. Moganavally

    2016-03-01

    Full Text Available Water plays a vital role to human and other living organisms. Due to the effluent coming from chemical industries, the industrial activity, contamination of ground water level is goes on increasing nowadays. Therefore, there is a need to develop technologies that can remove toxic pollutants in wastewater. Hence the cross linked Carboxymethyl chitosan(CMC/ 2,3-dimethoxy Benzaldehyde Schiff base complex has been synthesized and characterized by using FT-IR and SEM analysis. All these results revealed that cross linked Schiff base has formed with high adsorption capacity. The prepared effective adsorbent used for the removal of heavy metals like lead (II and cadmium (II ions from aqueous solution and the adsorption data follow the Freundlich model, which follows pseudo first order kinetics. Effect of various parameters like solution pH, adsorbent dose and contact time for the removal of heavy metals has been studied. The synthesized sample undergoes catalytic oxidation process significantly at 24 hrs. The results showed that cross linked Schiff base is an effective, eco-friendly, low-cost adsorbent.

  13. Removal of P4, PH3 and H2S from Yellow Phosphoric Tail Gas by a Catalytic Oxidation Process

    Institute of Scientific and Technical Information of China (English)

    NingPing; Hans-JoergBart; MaLiping; WangXueqian

    2004-01-01

    Yellow phosphorus tail gas is a resource used to produce bulk chemicals, such as formates, oxalates, and methanol after its pretreatment and purification. In this study, catalytic oxidation of phosphorus and hydrogen sulfide in yellow phosphorus tail gas was investigated on an ordinary activated carbon (OAC) and a home-made catalyst KU2. The adsorption characteristics of phosphorus and hydrogen sulfide on the catalysts were studied in a fixed-bed system at different temperatures between 20℃ and 140℃ at atmospheric pressure. Both KU2 and OAC are proved to be effective catalysts in the catalytic oxidation process (COP) for H2S and PH3 removal. Purification efficiency increased with the increase of temperature and oxygen concentration in yellow phosphorus tail gases. Under optimized operation conditions, the product gases with a content of hydrogen sulfide <5mg/m3 and total phosphorus <5mg/m3 were obtained by using the COP process. Deactivated catalysts could be restored to the original activated state, even after several regenerations. A mathematical model was developed to simulate the experimental results and the mass transport coefficient from the experiment was evaluated. Good agreement between the experimental breakthrough curves and the model predictions was observed.

  14. Reducing NOx emissions with Group IIIB compounds

    International Nuclear Information System (INIS)

    This patent describes improvement in a process for the catalytic cracking of a heavy hydrocarbon feed containing nitrogen compounds by contact with a circulating inventory of catalytic cracking catalyst to produce catalytically cracked products and spent catalyst containing coke comprising nitrogen compounds. The spent catalyst is regenerated by contact with oxygen or an oxygen-containing gas in a catalyst regeneration zone operating at catalyst regeneration conditions to produce hot regenerated catalyst which is recycled to catalytically crack the heavy feed and the catalyst regeneration zone produces a flue gas comprising CO, CO2 and oxides of nitrogen (NOx). The improvement comprises: reducing the NOx content of the flue gas by adding to the circulating catalyst inventory an additive comprising discrete particles comprising oxides of Group IIIB elements, exclusive of Group III elements which are ion exchanged or impregnated into the cracking catalyst, the additive being added in an amount sufficient to reduce the production of NOx relative to operation without the additive

  15. 2,4-Dichlorophenol hydroxylase for chlorophenol removal: Substrate specificity and catalytic activity.

    Science.gov (United States)

    Ren, Hejun; Li, Qingchao; Zhan, Yang; Fang, Xuexun; Yu, Dahai

    2016-01-01

    Chlorophenols (CPs) are common environmental pollutants. As such, different treatments have been assessed to facilitate their removal. In this study, 2,4-dichlorophenol (2,4-DCP) hydroxylase was used to systematically investigate the activity and removal ability of 19CP congeners at 25 and 0 °C. Results demonstrated that 2,4-DCP hydroxylase exhibited a broad substrate specificity to CPs. The activities of 2,4-DCP hydroxylase against specific CP congeners, including 3-CP, 2,3,6-trichlorophenol, 2-CP, and 2,3-DCP, were higher than those against 2,4-DCP, which is the preferred substrate of previously reported 2,4-DCP hydroxylase. To verify whether cofactors are necessary to promote hydroxylase activity against CP congeners, we added FAD and found that the added FAD induced a 1.33-fold to 5.13-fold significant increase in hydroxylase activity against different CP congeners. The metabolic pathways of the CP degradation in the enzymatic hydroxylation step were preliminarily proposed on the basis of the analyses of the enzymatic activities against 19CP congeners. We found that the high activity and removal rate of 2,4-DCP hydroxylase against CPs at 0 °C enhance the low-temperature-adaptability of this enzyme to the CP congeners; as such, the proposed removal process may be applied to biochemical, bioremediation, and industrial processes, particularly in cold environments. PMID:26672451

  16. Heterogeneous photo-assisted Fenton catalytic removal of tetracycline using Fe-Ce pillared bentonite

    Institute of Scientific and Technical Information of China (English)

    张亚平; 贾成光; 彭然; 马丰; 欧光南

    2014-01-01

    In the present work, a novel heterogeneous photo-Fenton catalyst was prepared by iron and cerium pillared bentonite. The catalyst Fe-Ce/bentonite was characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), Brunauer-Emmett-Teller (BET) and scanning electron microscopy (SEM) methods. It is found that Fe and Ce intercalate into the silicate layers of bentonite successfully. Tetracycline was removed by heterogeneous photo-Fenton reaction using the catalyst in this work. The effects of different reaction systems, hydrogen peroxide concentration, initial pH, catalyst dosage, UV power and introduction of different anions on degradation were investigated in details. The stability of catalyst was investigated through recycling experiment. The results show that removal rate of tetracycline is 98.13%under the conditions of 15 mmol/L H2O2, 0.50 g/L catalyst dosage, initial pH 3.0, 11 W UV lamp power and 60 min reaction time. However, the removal rate decreases after adding some anions. The hydroxyl radical plays an important role in heterogeneous photo-assisted Fenton degradation of tetracycline. The catalyst is very stable and can be recycled many times.

  17. Economical way to synthesize SSZ-13 with abundant ion-exchanged Cu+ for an extraordinary performance in selective catalytic reduction (SCR) of NOx by ammonia.

    Science.gov (United States)

    Chen, Biaohua; Xu, Ruinian; Zhang, Runduo; Liu, Ning

    2014-12-01

    In this study, an economical way for SSZ-13 preparation with the essentially cheap choline chloride as template has been attempted. The as-synthesized SSZ-13 zeolite after ion exchange by copper nitrate solution exhibited a superior SCR performance (over 95% NOx conversion across a broad range from 150 to 400 °C) to the traditional zeolite-based catalysts of Cu-Beta and Cu-ZSM-5. Furthermore, the opportune size of pore opening (∼3.8 Å) made Cu-SSZ-13 exhibiting the best selectivity to N2 as well as satisfactory tolerance toward SO2 and C3H6 poisonings. The characterization (XRD, XPS, XRF, and H2-TPR) of samples confirmed that Cu-SSZ-13 possessed the most abundant Cu cations among three investigated Cu-zeolites; furthermore, either on the surface or in the bulk the ratio of Cu(+)/Cu(2+) ions for Cu-SSZ-13 is also the highest. New finding was announced that CHA-type topology is in favor of the formation of copper cations, especially generating much more Cu(+) ions than the others, rather than CuO. The activity test of Cu(CuCl)-ZSM-5 (prepared by a solid-state ion-exchange method) clearly indicated that Cu(+) ions could make a major contribution to the low-temperature deNOx activity. The activity of protonic zeolites (H-SSZ-13, H-Beta, H-ZSM-5) revealed the topology effect on SCR performances. PMID:25365767

  18. Economical way to synthesize SSZ-13 with abundant ion-exchanged Cu+ for an extraordinary performance in selective catalytic reduction (SCR) of NOx by ammonia.

    Science.gov (United States)

    Chen, Biaohua; Xu, Ruinian; Zhang, Runduo; Liu, Ning

    2014-12-01

    In this study, an economical way for SSZ-13 preparation with the essentially cheap choline chloride as template has been attempted. The as-synthesized SSZ-13 zeolite after ion exchange by copper nitrate solution exhibited a superior SCR performance (over 95% NOx conversion across a broad range from 150 to 400 °C) to the traditional zeolite-based catalysts of Cu-Beta and Cu-ZSM-5. Furthermore, the opportune size of pore opening (∼3.8 Å) made Cu-SSZ-13 exhibiting the best selectivity to N2 as well as satisfactory tolerance toward SO2 and C3H6 poisonings. The characterization (XRD, XPS, XRF, and H2-TPR) of samples confirmed that Cu-SSZ-13 possessed the most abundant Cu cations among three investigated Cu-zeolites; furthermore, either on the surface or in the bulk the ratio of Cu(+)/Cu(2+) ions for Cu-SSZ-13 is also the highest. New finding was announced that CHA-type topology is in favor of the formation of copper cations, especially generating much more Cu(+) ions than the others, rather than CuO. The activity test of Cu(CuCl)-ZSM-5 (prepared by a solid-state ion-exchange method) clearly indicated that Cu(+) ions could make a major contribution to the low-temperature deNOx activity. The activity of protonic zeolites (H-SSZ-13, H-Beta, H-ZSM-5) revealed the topology effect on SCR performances.

  19. Optimization of internals for Selective Catalytic Reduction (SCR) for NO removal.

    Science.gov (United States)

    Lei, Zhigang; Wen, Cuiping; Chen, Biaohua

    2011-04-15

    This work tried to identify the relationship between the internals of selective catalytic reduction (SCR) system and mixing performance for controlling ammonia (NH(3)) slip. In the SCR flow section, arranging the flow-guided internals can improve the uniformity of velocity distribution but is unfavorable for the uniformity of NH(3) concentration distribution. The ammonia injection grids (AIG) with four kinds of nozzle diameters (i.e., 1.0 mm, 1.5 mm, 2.0 mm, and mixed diameters) were investigated, and it was found that the AIG with mixed nozzle diameters in which A3, A4, B3, and B4 nozzles' diameters are 1.0 mm and other nozzles' diameters are 1.5 mm is the most favorable for the uniformity of NH(3) concentration distribution. In the SCR reactor section, the appropriate space length between two catalyst layers, which serves as gas mixing in order to prevent maldistribution of gas concentrations into the second catalyst layer, under the investigated conditions is about 100, 1000, and 12 mm for honeycomb-like cordierite catalyst, plate-type catalysts with parallel channel arrangement, and with cross channel arrangement, respectively. Therefore, the cross channel arrangement is superior to the parallel channel arrangement in saving the SCR reactor volume.

  20. Nitrogen Isotope Composition of Thermally Produced NOx from Various Fossil-Fuel Combustion Sources.

    Science.gov (United States)

    Walters, Wendell W; Tharp, Bruce D; Fang, Huan; Kozak, Brian J; Michalski, Greg

    2015-10-01

    The nitrogen stable isotope composition of NOx (δ(15)N-NOx) may be a useful indicator for NOx source partitioning, which would help constrain NOx source contributions in nitrogen deposition studies. However, there is large uncertainty in the δ(15)N-NOx values for anthropogenic sources other than on-road vehicles and coal-fired energy generating units. To this end, this study presents a broad analysis of δ(15)N-NOx from several fossil-fuel combustion sources that includes: airplanes, gasoline-powered vehicles not equipped with a three-way catalytic converter, lawn equipment, utility vehicles, urban buses, semitrucks, residential gas furnaces, and natural-gas-fired power plants. A relatively large range of δ(15)N-NOx values was measured from -28.1‰ to 8.5‰ for individual exhaust/flue samples that generally tended to be negative due to the kinetic isotope effect associated with thermal NOx production. A negative correlation between NOx concentrations and δ(15)N-NOx for fossil-fuel combustion sources equipped with selective catalytic reducers was observed, suggesting that the catalytic reduction of NOx increases δ(15)N-NOx values relative to the NOx produced through fossil-fuel combustion processes. Combining the δ(15)N-NOx measured in this study with previous published values, a δ(15)N-NOx regional and seasonal isoscape was constructed for the contiguous U.S., which demonstrates seasonal and regional importance of various NOx sources.

  1. Influence of calcination temperature on selective catalytic reduction of NOx with NH3 over CeO2-ZrO2-WO3 catalyst

    Institute of Scientific and Technical Information of China (English)

    李军燕; 宋忠贤; 宁平; 张秋林; 刘昕; 李昊; 黄真真

    2015-01-01

    A series of CeO2-ZrO2-WO3 catalysts for the selective catalytic reduction (SCR) of NO with NH3 were prepared by hydro-thermal method. The influence of calcination temperature on the catalytic activity, microstructure, surface acidity and redox behavior of CeO2-ZrO2-WO3 catalyst was investigated using various characterization methods. It was found that the CeO2-ZrO2-WO3 catalyst calcined at 600 ºC showed the best catalytic performance and excellent N2 selectivity, and yielded more than 90% NO conversion in a wide temperature range of 250–500 ºC with a space velocity (GHSV) of 60000 h–1. As the calcination temperature was increased from 400 to 600 ºC, the NO conversion obviously increased, but decreased at higher calcination temperature. The results implied that the higher surface area, the strongest synergistic interaction, the superior redox property and the highly dispersed or amorphous WO3 species contributed to the excellent SCR activity of the CeO2-ZrO2-WO3 catalyst calcined at 600 ºC.

  2. SOx-NOx-Rox Box{trademark} flue gas clean-up demonstration. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

    Babcock and Wilcox`s (B and W) SOx-NOx-Rox Box{trademark} process effectively removes SOx, NOx and particulate (Rox) from flue gas generated from coal-fired boilers in a single unit operation, a high temperature baghouse. The SNRB technology utilizes dry sorbent injection upstream of the baghouse for removal of SOx and ammonia injection upstream of a zeolitic selective catalytic reduction (SCR) catalyst incorporated in the baghouse to reduce NOx emissions. Because the SOx and NOx removal processes require operation at elevated gas temperatures (800--900 F) for high removal efficiency, high-temperature fabric filter bags are used in the baghouse. The SNRB technology evolved from the bench and laboratory pilot scale to be successfully demonstrated at the 5-MWe field scale. This report represents the completion of Milestone M14 as specified in the Work Plan. B and W tested the SNRB pollution control system at a 5-MWe demonstration facility at Ohio Edison`s R.E. Burger Plant located near Shadyside, Ohio. The design and operation were influenced by the results from laboratory pilot testing at B and W`s Alliance Research Center. The intent was to demonstrate the commercial feasibility of the SNRB process. The SNRB facility treated a 30,000 ACFM flue gas slipstream from Boiler No. 8. Operation of the facility began in May 1992 and was completed in May 1993. About 2,300 hours of high-temperature operation were achieved. The main emissions control performance goals of: greater than 70% SO{sub 2} removal using a calcium-based sorbent; greater than 90% NOx removal with minimal ammonia slip; and particulate emissions in compliance with the New Source Performance Standards (NSPS) of 0.03 lb/million Btu were exceeded simultaneously in the demonstration program when the facility was operated at optimal conditions. Testing also showed significant reductions in emissions of some hazardous air pollutants.

  3. Fast microwave-assisted catalytic gasification of biomass for syngas production and tar removal.

    Science.gov (United States)

    Xie, Qinglong; Borges, Fernanda Cabral; Cheng, Yanling; Wan, Yiqin; Li, Yun; Lin, Xiangyang; Liu, Yuhuan; Hussain, Fida; Chen, Paul; Ruan, Roger

    2014-03-01

    In the present study, a microwave-assisted biomass gasification system was developed for syngas production. Three catalysts including Fe, Co and Ni with Al2O3 support were examined and compared for their effects on syngas production and tar removal. Experimental results showed that microwave is an effective heating method for biomass gasification. Ni/Al2O3 was found to be the most effective catalyst for syngas production and tar removal. The gas yield reached above 80% and the composition of tar was the simplest when Ni/Al2O3 catalyst was used. The optimal ratio of catalyst to biomass was determined to be 1:5-1:3. The addition of steam was found to be able to improve the gas production and syngas quality. Results of XRD analyses demonstrated that Ni/Al2O3 catalyst has good stability during gasification process. Finally, a new concept of microwave-assisted dual fluidized bed gasifier was put forward for the first time in this study. PMID:24508907

  4. Roles of catalytic oxidation in control of vehicle exhaust emissions

    International Nuclear Information System (INIS)

    Catalytic oxidation was initially associated with the early development of catalysis and it subsequently became a part of many industrial processes, so it is not surprising it was used to remove hydrocarbons and CO when it became necessary to control these emissions from cars. Later NOx was reduced in a process involving reduction over a Pt/Rh catalyst followed by air injection in front of a Pt-based oxidation catalyst. If over-reduction of NO to NH3 took place, or if H2S was produced, it was important these undesirable species were converted to NOx and SOx in the catalytic oxidation stage. When exhaust gas composition could be kept stoichiometric hydrocarbons, CO and NOx were simultaneously converted over a single Pt/Rh three-way catalyst (TWC). With modern TWCs car tailpipe emissions can be exceptionally low. NO is not catalytically dissociated to O2 and N2 in the presence of O2, it can only be reduced to N2. Its control from lean-burn gasoline engines involves catalytic oxidation to NO2 and thence nitrate that is stored and periodically reduced to N2 by exhaust gas enrichment. This method is being modified for diesel engines. These engines produce soot, and filtration is being introduced to remove it. The exhaust temperature of heavy-duty diesels is sufficient (250-400oC) for NO to be catalytically oxidised to NO2 over an upstream platinum catalyst that smoothly oxidises soot in the filter. The exhaust gas temperature of passenger car diesels is too low for this to take place all of the time, so trapped soot is periodically burnt in O2 above 550oC. Catalytic oxidation of higher than normal amounts of hydrocarbon and CO over an upstream catalyst is used to give sufficient temperature for soot combustion with O2 to take place. (author)

  5. Nitrogen oxides from waste incineration: control by selective non-catalytic reduction.

    Science.gov (United States)

    Zandaryaa, S; Gavasci, R; Lombardi, F; Fiore, A

    2001-01-01

    An experimental study of the selective non-catalytic reduction (SNCR) process was carried out to determine the efficiency of NOx removal and NH3 mass balance, the NOx reducing reagent used. Experimental tests were conducted on a full-scale SNCR system installed in a hospital waste incineration plant. Anhydrous NH3 was injected at the boiler entrance for NOx removal. Ammonia was analyzed after each flue-gas treatment unit in order to establish its mass balance and NH3 slip in the stack gas was monitored as well. The effective fraction of NH3 for the thermal NOx reduction was calculated from measured values of injected and residual NH3. Results show that a NOx reduction efficiency in the range of 46.7-76.7% is possible at a NH3/NO molar ratio of 0.9-1.5. The fraction of NH3 used in NOx removal was found to decrease with rising NH3/NO molar ratio. The NH3 slip in the stack gas was very low, below permitted limits, even at the higher NH3 dosages used. No direct correlation was found between the NH3/NO molar ratio and the NH3 slip in the stack gas since the major part of the residual NH3 was converted into ammonium salts in the dry scrubbing reactor and subsequently collected in the fabric filter. Moreover, another fraction of NH3 was dissolved in the scrubbing liquor.

  6. Removal of NOx from Flue Gas with DC Corona Radical Shower System%采用直流电晕自由基簇射系统脱除烟气中NOx的研究

    Institute of Scientific and Technical Information of China (English)

    林赫; 高翔; 骆仲泱; 岑可法; 裴梅香; 黄震

    2004-01-01

    Removal of NOx from flue gas with DC corona radical shower system was investigated in the experiment. The re sults show that both the composition and the flow rate of the gas fed into the nozzles have effect on the V-I characteristic of the corona discharge. The steady curtain shape streamer corona occurs when the flow rate of the fed gas is adjusted. The vapor in the flue gas not only affects the V-I characteristic of the corona discharge, but also enhances the NOx removing efficiency.%研究了采用直流电晕自由基簇射系统脱除烟气中的NOx.实验结果表明,电极喷嘴中的气体组分和流量对电晕放电的电压-电流(V-I)特性产生影响,适当调节电极喷嘴中的气体流量可以产生帘状流光电晕.烟气中的水蒸气不仅对电晕放电的V-I特性产生影响,而且提高NOx的脱除效率.

  7. Ammonia-Free NOx Control System

    Energy Technology Data Exchange (ETDEWEB)

    S. Wu

    2003-12-31

    Research is being conducted under United States Department of Energy (DOE) Contract DEFC26-03NT41865 to develop a new technology to achieve very low levels of NOx emissions from pulverized coal fired boiler systems by employing a novel system level integration between the PC combustion process and the catalytic NOx reduction with CO present in the combustion flue gas. The combustor design and operating conditions will be optimized to achieve atypical flue gas conditions. This approach will not only suppress NOx generation during combustion but also further reduce NOx over a downstream catalytic reactor that does not require addition of an external reductant, such as ammonia. This report describes the work performed during the October 1 to December 31, 2003 time period.

  8. Ammonia-Free NOx Control System

    Energy Technology Data Exchange (ETDEWEB)

    Song Wu; Zhen Fan; Andrew H. Seltzer; Richard G. Herman

    2004-09-30

    Research is being conducted under United States Department of Energy (DOE) Contract DEFC26-03NT41865 to develop a new technology to achieve very low levels of NOx emissions from pulverized coal fired boiler systems by employing a novel system level integration between the PC combustion process and the catalytic NOx reduction with CO present in the combustion flue gas. The combustor design and operating conditions will be optimized to achieve atypical flue gas conditions. This approach will not only suppress NOx generation during combustion but also further reduce NOx over a downstream catalytic reactor that does not require addition of an external reductant, such as ammonia. This report describes the work performed during the July 1 to September 30, 2004 time period.

  9. Ammonia-Free NOx Control System

    Energy Technology Data Exchange (ETDEWEB)

    S. Wu; Z. Fan; R. Herman

    2004-03-31

    Research is being conducted under United States Department of Energy (DOE) Contract DEFC26-03NT41865 to develop a new technology to achieve very low levels of NOx emissions from pulverized coal fired boiler systems by employing a novel system level integration between the PC combustion process and the catalytic NOx reduction with CO present in the combustion flue gas. The combustor design and operating conditions will be optimized to achieve atypical flue gas conditions. This approach will not only suppress NOx generation during combustion but also further reduce NOx over a downstream catalytic reactor that does not require addition of an external reductant, such as ammonia. This report describes the work performed during the January 1 to March 31, 2004 time period.

  10. The Cu-CHA deNOx Catalyst in Action: Temperature-Dependent NH3-Assisted Selective Catalytic Reduction Monitored by Operando XAS and XES.

    Science.gov (United States)

    Lomachenko, Kirill A; Borfecchia, Elisa; Negri, Chiara; Berlier, Gloria; Lamberti, Carlo; Beato, Pablo; Falsig, Hanne; Bordiga, Silvia

    2016-09-21

    The small-pore Cu-CHA zeolite is today the object of intensive research efforts to rationalize its outstanding performance in the NH3-assisted selective catalytic reduction (SCR) of harmful nitrogen oxides and to unveil the SCR mechanism. Herein we exploit operando X-ray spectroscopies to monitor the Cu-CHA catalyst in action during NH3-SCR in the 150-400 °C range, targeting Cu oxidation state, mobility, and preferential N or O ligation as a function of reaction temperature. By combining operando XANES, EXAFS, and vtc-XES, we unambiguously identify two distinct regimes for the atomic-scale behavior of Cu active-sites. Low-temperature SCR, up to ∼200 °C, is characterized by balanced populations of Cu(I)/Cu(II) sites and dominated by mobile NH3-solvated Cu-species. From 250 °C upward, in correspondence to the steep increase in catalytic activity, the largely dominant Cu-species are framework-coordinated Cu(II) sites, likely representing the active sites for high-temperature SCR. PMID:27532483

  11. Nox regulation of smooth muscle contraction

    OpenAIRE

    Ritsick, Darren R.; Edens, William A.; Finnerty, Victoria; Lambeth, J. David

    2007-01-01

    The catalytic subunit, gp91phox (a.k.a., Nox2) of the NADPH-oxidase of mammalian phagocytes is activated by microbes and immune mediators to produce large amounts of reactive oxygen species (ROS) which participate in microbial killing. Homologs of gp91phox, the Nox and Duox enzymes, were recently described in a range of organisms, including plants, vertebrates, and invertebrates such as Drosophila melanogaster. While their enzymology and cell biology is being extensively studied in many labor...

  12. Evaluation of Performance Catalytic Ozonation with Activated Alumina in the Removal of Pentachlorophenol from Aqueous Solutions and Study of the Intermediates

    Directory of Open Access Journals (Sweden)

    A.R. Rahmani

    2013-04-01

    Full Text Available Introduction & Objective: Pentachlorophenol (PCP is a refractory phenolic compound. Owing to its high poisonous and carcinogenic nature, PCP is on the US EPA’s list of priority pollut-ants. As a result, it is one of the important pollutants that need to be removed during water and wastewater reclamation processes. The efficiency of the catalytic ozonation process (COP was assessed based on the removal of PCP from the aqueous solutions and its inter-mediates were studied. Materials & Methods: In this experimental study, catalytic ozonation process was applied to remove PCP in aqueous solution and its intermediate was studied. The influence of several variables was examined, including pH of solution, contact time, dissolved ozone concentra-tion and dosage of -Al2O3 in semi batch reactor. The determination of PCP concentrations in solutions was analyzed by HPLC using the UV detector (254nm. Results: Our results showed that the removal effectiveness of PCP has been increased by ris-ing pH, contact time, catalyst dosage and dissolved ozone concentration. Removal efficiency of PCP was determined 89% and 100% in SOP and AOP after 60 minutes, respectively. The pHzpc of alumina was determined 8.6. Conclusion: Due to high performance of -Al2O3 as catalyst in catalytic ozonation and increas-ing the PCP removal, it is thus concluded that the integrated catalytic ozonation is a promis-ing and economically affordable technology for the treatment of wastewater containing pen-tachlorophenol and other similar compounds. (Sci J Hamadan Univ Med Sci 2013; 20 (1:77-85

  13. Upgrading V2O5-WO3/TiO2 deNOx Catalyst with TiO2-SiO2 Support Prepared from Ti-Bearing Blast Furnace Slag

    OpenAIRE

    Tuyetsuong Tran; Jian Yu; Lina Gan; Feng Guo; Dinhtuan Phan; Guangwen Xu

    2016-01-01

    The study is devoted to developing a rather high-efficiency NH3-SCR (selective catalytic reduction) catalyst for NOx removal using TiO2-SiO2 support made from blast furnace slag. Through adjusting hydrolytic pH value of TiOSO4 solution obtained from acidolysis of slag with 70 wt. % H2SO4, a series of TiO2-SiO2 mixed oxides was prepared to have different mass ratios of TiO2 to SiO2. The supports are further impregnated with V2O5 and WO3 to make the SCR catalysts for NOx removal. Characterizing...

  14. Shape-Controllable Synthesis of Peroxidase-Like Fe3O4 Nanoparticles for Catalytic Removal of Organic Pollutants

    Science.gov (United States)

    Wan, Dong; Li, Wenbing; Wang, Guanghua; Wei, Xiaobi

    2016-10-01

    The shape of Fe3O4 nanoparticles is controlled using a simple oxidation-precipitation method without any surfactant. The morphology and structure of the obtained Fe3O4 nanoparticles were characterized by using x-ray diffraction, scanning electron microscopy, x-ray photoelectron spectroscopy, N2 physisorption and vibrating sample magnetometer. As-prepared Fe3O4 samples showed octahedron, cube, hexagonal plate and sphere morphologies. Peroxidase-like activity of the four nanostructures was evaluated for catalytic removal of organic pollutants in the presence of H2O2, using rhodamine B as a model compound. The results showed that the H2O2-activating ability of the Fe3O4 nanocrystals was structure dependent and followed the order sphere > cube > octahedron > hexagonal plate, which was closely related to their surface FeII/FeIII ratios or crystal planes. The reusability of Fe3O4 spheres was also investigated after five successive runs, which demonstrated the promising application of the catalyst in the degradation of organic pollutants. This investigation is of great significance for the heterogeneous catalysts with enhanced activity and practical application.

  15. Removal and Conversion of Tar in Syngas from Woody Biomass Gasification for Power Utilization Using Catalytic Hydrocracking

    Directory of Open Access Journals (Sweden)

    Jiu Huang

    2011-08-01

    Full Text Available Biomass gasification has yet to obtain industrial acceptance. The high residual tar concentrations in syngas prevent any ambitious utilization. In this paper a novel gas purification technology based on catalytic hydrocracking is introduced, whereby most of the tarry components can be converted and removed. Pilot scale experiments were carried out with an updraft gasifier. The hydrocracking catalyst was palladium (Pd. The results show the dominant role of temperature and flow rate. At a constant flow rate of 20 Nm3/h and temperatures of 500 °C, 600 °C and 700 °C the tar conversion rates reached 44.9%, 78.1% and 92.3%, respectively. These results could be increased up to 98.6% and 99.3% by using an operating temperature of 700 °C and lower flow rates of 15 Nm3/h and 10 Nm3/h. The syngas quality after the purification process at 700 °C/10 Nm3/h is acceptable for inner combustion (IC gas engine utilization.

  16. Shape-Controllable Synthesis of Peroxidase-Like Fe3O4 Nanoparticles for Catalytic Removal of Organic Pollutants

    Science.gov (United States)

    Wan, Dong; Li, Wenbing; Wang, Guanghua; Wei, Xiaobi

    2016-08-01

    The shape of Fe3O4 nanoparticles is controlled using a simple oxidation-precipitation method without any surfactant. The morphology and structure of the obtained Fe3O4 nanoparticles were characterized by using x-ray diffraction, scanning electron microscopy, x-ray photoelectron spectroscopy, N2 physisorption and vibrating sample magnetometer. As-prepared Fe3O4 samples showed octahedron, cube, hexagonal plate and sphere morphologies. Peroxidase-like activity of the four nanostructures was evaluated for catalytic removal of organic pollutants in the presence of H2O2, using rhodamine B as a model compound. The results showed that the H2O2-activating ability of the Fe3O4 nanocrystals was structure dependent and followed the order sphere > cube > octahedron > hexagonal plate, which was closely related to their surface FeII/FeIII ratios or crystal planes. The reusability of Fe3O4 spheres was also investigated after five successive runs, which demonstrated the promising application of the catalyst in the degradation of organic pollutants. This investigation is of great significance for the heterogeneous catalysts with enhanced activity and practical application.

  17. Low Absorption Vitreous Carbon Reactors for Operando XAS: A Case Study on Cu/Zeolites for Selective Catalytic Reduction of NOx by NH3

    Energy Technology Data Exchange (ETDEWEB)

    Kispersky, Vincent F.; Kropf, Jeremy; Ribeiro, Fabio H; Miller, Jeffrey T

    2012-01-01

    We describe the use of vitreous carbon as an improved reactor material for an operando X-ray absorption spectroscopy (XAS) plug-flow reactor. These tubes significantly broaden the operating range for operando experiments. Using selective catalytic reduction (SCR) of NOx by NH₃ on Cu/Zeolites (SSZ-13, SAPO-34 and ZSM-5) as an example reaction, we illustrate the high-quality XAS data achievable with these reactors. The operando experiments showed that in Standard SCR conditions of 300 ppm NO, 300 ppm NH₃, 5% O₂, 5% H₂O, 5% CO₂ and balance He at 200 °C, the Cu was a mixture of Cu(I) and Cu(II) oxidation states. XANES and EXAFS fitting found the percent of Cu(I) to be 15%, 45% and 65% for SSZ-13, SAPO-34 and ZSM-5, respectively. For Standard SCR, the catalytic rates per mole of Cu for Cu/SSZ-13 and Cu/SAPO-34 were about one third of the rate per mole of Cu on Cu/ZSM-5. Based on the apparent lack of correlation of rate with the presence of Cu(I), we propose that the reaction occurs via a redox cycle of Cu(I) and Cu(II). Cu(I) was not found in in situSCR experiments on Cu/Zeolites under the same conditions, demonstrating a possible pitfall of in situ measurements. A Cu/SiO₂ catalyst, reduced in H₂ at 300 °C, was also used to demonstrate the reactor's operando capabilities using a bending magnet beamline. Analysis of the EXAFS data showed the Cu/SiO₂ catalyst to be in a partially reduced Cu metal–Cu(I) state. In addition to improvements in data quality, the reactors are superior in temperature, stability, strength and ease of use compared to previously proposed borosilicate glass, polyimide tubing, beryllium and capillary reactors. The solid carbon tubes are non-porous, machinable, can be operated at high pressure (tested at 25 bar), are inert, have high material purity and high X-ray transmittance.

  18. Mesostructured Cu–Mn–Ce–O composites with homogeneous bulk composition for chlorobenzene removal: Catalytic performance and microactivation course

    Energy Technology Data Exchange (ETDEWEB)

    He, Chi, E-mail: chi_he@mail.xjtu.edu.cn [Department of Environmental Science and Engineering, School of Energy and Power Engineering, Xi' an Jiaotong University, Xi' an 710049 (China); Yu, Yanke [Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Shi, Jianwen [Center of Nanomaterials for Renewable Energy, State Key Laboratory of Electrical Insulation and Power Equipment, School of Electrical Engineering, Xi' an Jiaotong University, Xi' an 710049 (China); Shen, Qun [Research Center for Greenhouse Gases and Environmental Engineering, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210 (China); Chen, Jinsheng [Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Liu, Hongxia, E-mail: hxliu72@mail.xjtu.edu.cn [Department of Environmental Science and Engineering, School of Energy and Power Engineering, Xi' an Jiaotong University, Xi' an 710049 (China)

    2015-05-01

    Cu–Mn–Ce–O composites with enhanced surface area and developed mesoporosity were synthesized using a homogeneous coprecipitation (hcp) method, and were tested in the catalytic destruction of chlorobenzene (CB). X-ray diffraction (XRD), N{sub 2} adsorption/desorption, field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), temperature programmed reduction (H{sub 2}-TPR), temperature programmed desorption of CB/O{sub 2} (CB/O{sub 2}-TPD), and diffuse reflectance ultraviolet visible spectroscopy (DRUV-Vis) were used to characterize the structure and textural properties of catalysts. Mn and Cu enter CeO{sub 2} matrix with a fluorite-like structure, and produce large amounts of oxygen vacancies. Addition of manganese promotes the formation of reduced copper phase, and the presence of large numbers of high valence Mn{sup 4+} ions strongly enhances the redox couple of Cu{sup +}–Cu{sup 2+} in the composites. Both the synthesis protocol and metal doping amount significantly affect the catalyst reducibility, surface state and oxygen density. Cu{sub 0.15}Mn{sub 0.15}Ce{sub 0.85}O{sub x} synthesized via the hcp method exhibits the highest catalytic activity with 90% of chlorobenzene destructed at 255 °C (CO{sub 2} selectivity > 99.5%). Enriched surface oxygen, excellent active oxygen mobility and CB adsorption ability guarantee the superior activity and stability of Cu–Mn–Ce–O composite catalysts. Nucleophilic and electrophilic substitutions happen in sequence during chlorobenzene destruction, and the adsorbed Cl can be finally removed in the form of Cl{sub 2} via the Deacon reaction. Furthermore, the incorporation of CuO and MnO{sub x} phases can inhibit the formation of organic byproducts, such as phenolates, maleates, and o-benzoquinone-type species, especially at elevated reaction temperatures. - Highlights: • Cu–Mn–Ce–O mesoporous oxides possess enhanced surface oxygen

  19. Catalytic ozonation of organic pollutants from bio-treated dyeing and finishing wastewater using recycled waste iron shavings as a catalyst: Removal and pathways.

    Science.gov (United States)

    Wu, Jin; Ma, Luming; Chen, Yunlu; Cheng, Yunqin; Liu, Yan; Zha, Xiaosong

    2016-04-01

    Catalytic ozonation of organic pollutants from actual bio-treated dyeing and finishing wastewater (BDFW) with iron shavings was investigated. Catalytic ozonation effectively removed organic pollutants at initial pH values of 7.18-7.52, and the chemical oxygen demand (COD) level decreased from 142 to 70 mg·L(-1) with a discharge limitation of 80 mg·L(-1). A total of 100% and 42% of the proteins and polysaccharides, respectively, were removed with a decrease in their contribution to the soluble COD from 76% to 41%. Among the 218 organic species detected by liquid chromatography-mass spectrometry, 58, 77, 79 and 4 species were completely removed, partially removed, increased and newly generated, respectively. Species including textile auxiliaries and dye intermediates were detected by gas chromatography-mass spectrometry. The inhibitory effect decreased from 51% to 33%, suggesting a reduction in the acute toxicity. The enhanced effect was due to hydroxyl radical (OH) oxidation, co-precipitation and oxidation by other oxidants. The proteins were removed by OH oxidation (6%), by direct ozonation, co-precipitation and oxidation by other oxidants (94%). The corresponding values for polysaccharides were 21% and 21%, respectively. In addition, the iron shavings behaved well in successive runs. These results indicated that the process was favorable for engineering applications for removal of organic pollutants from BDFW. PMID:26849317

  20. Multiphase catalysts for selective reduction of NOx with hydrocarbons

    OpenAIRE

    Maisuls, Sergio Eduardo

    2000-01-01

    The combustion of fuels, to meet the society demands for energy, result in the emissi of large quantities of nitrogen oxides (NOx) to the environment. These pollutants cause severe environmental problems and present a serious hazard to the health. Nowadays, two methods for the control of NOx emission are employed. The selective catalytic reduction of NOx with NH3 (SCR), (for stationary sources such as power plants) and the three way catalyst (TWC), (for mobile sources such as automobiles). Th...

  1. Analysis and study on the performance variation of SCR DeNOx catalyst of Coal-Fired Boilers

    International Nuclear Information System (INIS)

    Nitrogen oxides (NOx) are one kind of harmful substances from the burning process of fossil fuel and air at high temperature. NOx emissions cause serious pollution on atmospheric environment. In this paper, coal-fired utility boilers were chosen as the object, NOx formation mechanism and control were studied, and SCR deNOx technology was used to control NOx emissions from coal-fired boilers. Analyzed the relationship between deNOx efficiency and characteristics of SCR DeNOx catalyst. Through analysis, affecting SCR DeNOx catalyst failure factors, change law of catalytic properties and technical measures to extend the service life of the catalyst were gotten. (author)

  2. Nox2 regulates endothelial cell cycle arrest and apoptosis via p21cip1 and p53

    OpenAIRE

    Li, Jian-Mei; Fan, Lampson M; George, Vinoj T.; Brooks, Gavin

    2007-01-01

    Endothelial cells (EC) express constitutively two major isoforms (Nox2 and Nox4) of the catalytic subunit of NADPH oxidase, which is a major source of endothelial reactive oxygen species. However, the individual roles of these Noxes in endothelial function remain unclear. We have investigated the role of Nox2 in nutrient deprivation-induced cell cycle arrest and apoptosis. In proliferating human dermal microvascular EC, Nox2 mRNA expression was low relative to Nox4 (Nox2:Nox4 ~1:13), but was ...

  3. A review on the removal of nitrogen oxides from polluted flow by bioreactors

    Energy Technology Data Exchange (ETDEWEB)

    Niu, H.; Leung, D.Y.C. [Hong Kong Univ., (China). Dept. of Mechanical Engineering

    2010-07-01

    China's emissions of nitrogen oxides (NOx) have increased exponentially over the past decades because of rapid economic growth driven by the generation of energy from fossil fuels. The main pollutants of NOx are nitric oxide (NO) and nitrogen dioxide (NO{sub 2}) which are harmful to the environment and human health. The conventional technologies used to control NOx emission from exhaust gas include selective catalytic reduction, selective non-catalytic reduction, adsorption and absorption scrubbing. This paper discussed the feasibility of removing NOx with conventional gas phase bioreactors such as biofilters, biotrickling filters and bioscrubbers. Alternative processes were also presented, such as membrane bioreactors, rotating drum biofilters and rotating biological contactors. The bioreactor appears to be superior to conventional technologies in terms of simplicity and economy in operation, low process energy requirements, and easy treatment of residual products. Two biologically-based NOx removal theories were also reviewed in this paper, notably nitrification and denitrification. The use of bacteria, fungi and microalgae were discussed and compared. It was concluded that the bioreactor is a promising technology that can be used to control NOx emitted during combustion processes. 15 refs., 1 tab., 2 figs.

  4. Implementation of NOx control technologies in petroleum refining applications, Mobil Torrance Refinery

    International Nuclear Information System (INIS)

    Existing NOx technologies implemented by the Mobil Torrance refinery have been reviewed. Technologies utilized are Lo-NOx burners, Ultra-Lo-NOx burners and selective catalytic reduction in boilers and process heaters, as well as selective non-catalytic reduction in fluid catalytic cracker/CO boiler applications. With the implementation of the Regional Clean Air Incentives Market (RECLAIM), research at Mobil is directed towards reducing operational costs and improving efficiency in selective catalytic reduction with high and low temperature catalysts. Research is also directed at improved selective non-catalytic reduction efficiency in CO boiler applications and at further NOx reduction in fluid catalytic cracker regenerator offgases. The implementation of proven and enhanced technology is expected to reduce refinery NOx emissions from 1734 metric tons per yr to 487 metric tons per yr by the year 2003. 4 refs., 7 figs

  5. Mn掺杂Ce0.7Zr0.3O2催化剂同时去除碳烟和氮氧化物的性能%Performance of Mn Doped Ce0.7Zr0.3O2 Catalysts for Simultaneous Removal of PM and NOx

    Institute of Scientific and Technical Information of China (English)

    朱昌权; 梁红; 李树华; 洪燕霞; 叶代启

    2011-01-01

    A series of x%Mn/Ce0.7Zr0.3O2 (x=O, 5, 10, 15, 30, 50) metal oxide catalysts were prepared by complexing combustion method with citric acid. The catalysts have been investigated to remove of carbon particulate matter (PM)and nitrogen oxides (NOx) emitted from diesel engines. The samples were characterized by XRD, low temperature adsorption-desorption, H2-TPR, O2-TPD and in situ Diffuse Reflectance IR Fourier-Transform spectroscopy (in situ DRIFTs). The results indicate that the ceria-zirconia solid solutions with different Mn-doping content form the modified solid solution structures. During the catalytic reaction for simultaneous removal of PM and NOx, their catalytic performance is directly related to the oxidizing ability of these solid solution catalysts. Among them, 30%Mn/Ceo.7Zr0.3O2 catalyst has higher activity for simultaneous removal of PM and NOx. The ignition temperature and the most combustion temperature of PM are 298 and 504 ℃, and the most conversion of NO achieves 30.6%. On the basis of the experimental results of in situ DRIFTS, a reaction mechanism is proposed, which can preferably explain the reaction process of simultaneous removal of PM and NOx over 30%Mn/Ce07Zr0.3O2. Based on the results of O2-TPD and in situ DRIFTS, superoxide species (O2-) adsorbed on the surface of 30% Mr/Ce0.7Zr0.3O2 and nitrate species (NO3-) are active species during the reaction of PM and NOx, and further, the formation of the isocyanate species (-NCO) is confirmed.%采用柠檬酸络合燃烧法制备了一系列x%Mn/Ce0.7Zr0.3O2(x=0,5,10,15,30,50)复合金属氧化物催化剂,对其同时去除柴油机尾气中碳烟颗粒物(PM)和氮氧化物(NOx)反应的催化活性进行了评价,并采用XRD、低温氮吸附一脱附、H2.TPR、O2-TPD和原位漫反射红外光谱(in situ DRIFTS)等技术对催化剂的性能进行了表征.结果表明,不同含量Mn掺杂人铈锆固溶体中均形成了三元固溶体催化剂,在同时去除PM和NOx的催化

  6. NOx emissions in gas turbines: formation mechanism and reduction; Emissoes de NOx em turbinas a gas: mecanismos de formacao e algumas tecnologias de reducao

    Energy Technology Data Exchange (ETDEWEB)

    Gallego, Antonio Garrido; Martins, Gilberto; Gallo, Waldyr L.R. [Universidade Metodista de Piracicaba, SP (Brazil)]. E-mails: agallego@unimep.br; gmartins@unimep.br; gallo@fem.unicamp.br

    2000-06-01

    Some aspects related to the NOx emissions from industrial gas turbines are studied. Brazilian and international emission regulations are discussed. The main oxide formation mechanisms inside the combustion chamber are presented, and the main strategies for the reduction of NOx emission are explored (including water and steam injection, staged combustion, low-NOx burners and catalytic reduction). The need for a revision on Brazilian regulations for NOx is evidenced. (author)

  7. 脉冲电晕结合Ca(OH)2吸收法脱硫脱硝%Removal of SO2 and NOx by Pulsed Corona Combined with in situ Ca(OH)2 Absorption

    Institute of Scientific and Technical Information of China (English)

    黄立维; 党永霞

    2011-01-01

    Removal of SO2 and NOx by pulsed corona combined with in situ alkali absorption was experimentally investigated. In the reactor, a plate-wire-plate combination is devised for generating pulsed corona and then alkaline absorbent slurries were introduced into the reactor by a continuous band conveying system to capture the gaseous reaction products. It was found that both SO2 and NO could be removed by corona combined with in situ alkali absorption. The removal of SO2 increased to 75% with the corona discharge, compared with 60% removal only with Ca(OH)2 absorption. About 40% removal of NO was reached by pulsed corona combined with in situ Ca(OH)2 absorption. It was found that SO2 and NO in the gas stream are oxidized to SO3 and NO2 by pulsed corona respectively, and then absorbed by the alkali in the reactor. The removals of SO2 as well as NO were higher with Ca(OH)2 as the absorbent, compared with using CaCO3 or ZnO.

  8. Electron beam treatment of exhaust gas with high NOx concentration

    International Nuclear Information System (INIS)

    Simulated exhaust gases with a high NOx concentration, ranging from 200 to 1700 ppmv, were irradiated by an electron beam from an accelerator. In the first part of this study, only exhaust gases were treated. Low NOx removal efficiencies were obtained for high NOx concentrations, even with high irradiation doses applied. In the second part of study, gaseous ammonia or/and vapor ethanol were added to the exhaust gas before its inlet to the plasma reactor. These additions significantly enhanced the NOx removal efficiency. The synergistic effect of high SO2 concentration on NOx removal was observed. The combination of electron beam treatment with the introduction of the above additions and with the performance of irradiation under optimal parameters ensured high NOx removal efficiency without the application of a solid-state catalyst. (paper)

  9. Catalyst-Packed Non-Thermal Plasma Reactor for Removal of Nitrogen Oxides

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A single-stage plasma-catalytic reactor in which catalytic materials were packedwas used to remove nitrogen oxides. The packing material was scoria being made of various metaloxides including A12O3, MgO, TiO2, etc. Scoria was able to act not only as dielectric pelletsbut also as a catalyst in the presence of reducing agent such as ethylene and ammonia. Withoutplasma discharge, scoria did not work well as a catalyst in the temperature range of 100 °Cto 200 °C, showing less than 10% of NOx removal efficiency. When plasma is produced inside thereactor, the NOx removal efficiency could be increased to 60% in this temperature range.

  10. FCC DeSOx and DeNOx additive technology

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The fluid catalytic cracking(FCC) is the principal gasoline-producing process in the refinery. Considerable amounts of harmful sulfur oxides and nitrogen oxides (SOx and NOx ) are generated with the FCC operation. Impacted by strengthening environmental regulations and the current global emphasis on environmental protection and pollution abatement, refiners have been meaning to look for effective ways to control and reduce SOx and NOx emissions. FCC DeSOx and DeNOx additives is the most promising measure. The present paper reviews the developments in FCC DeSOx and DeNOx additive technology based on the respective authors' works, the future directions of the technology are also discussed.

  11. 环境友好的选择性催化还原氮氧化物催化剂%Environmental-friendly catalysts for the selective catalytic reduction of NOx

    Institute of Scientific and Technical Information of China (English)

    贺泓; 刘福东; 余运波; 单文坡

    2012-01-01

    Selective catalytic reduction (SCR) of nitrogen oxides (Nox) under oxygen-rich conditions is a research hotspot in the field of environmental catalysis, of which the core problem is to develop environmental-friendly, highly effective and stable SCR catalyst systems. At present, the NH3-SCR technique using urea/NH3 as reducing agent has already been widely applied for stationary flue gas denitrogenation and diesel engine exhaust purification. The HC-SCR technique using hydrogen carbons (HC) as reducing agent is also promising for practical application. For urea/NH3-SCR system, in this paper, the research progress of iron titanate catalyst, cerium-based oxide catalysts and small-pore zeolite catalysts is comprehensively summarized, including the catalyst structure, the SCR reaction mechanism, the improvement of low temperature activity and also the poisoning resistance performance. For HC-SCR system, herein, the SCR of NO* by higher HCs/diesel, and the achievements in the mechanism study of HC-SCR are summarized systematically, which can provide new guideline for the development and application of diesel-SCR technique.%富氧条件下的氮氧化物(NOx)选择性催化还原(SCR)是目前环境催化领域的研究热点,其核心问题是研发环境友好、高效稳定的SCR催化剂.目前,以NH3为还原剂的NH3-SCR已经大规模应用于固定源烟气脱硝和柴油车尾气净化,以碳氢化合物(HC)为还原剂的HC-SCR也有望实际应用.针对NH3-SCR,本文以作者研究的铁钛复合氧化物催化剂、铈基氧化物催化剂以及国际上新兴的小孔分子筛催化剂为例,从催化剂结构、SCR反应机理、催化剂低温活性改进以及抗中毒性能等诸多方面对该领域的研究进展做了较为全面的论述.针对HC-SCR催化剂,本文在综述长链HC及柴油选择性还原NOx研究现状的基础上,结合作者在HC-SCR反应机理方面的研究成果,展望了实现柴油-SCR的发展方向.

  12. Removal of Nox and Diesel Soot Particulates Catalyzed by Perovskite-type Oxide La0.9K0.1CoO3

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The catalytic performance of perovskite composite oxide catalyst La0.9 K0.1 CoO3 coated on catalyst supports by trnditional solid state reaction method and sol-gel method were investigated by a series of experiments.The result shows that the catalytic performance of the La0.9 K0.1 CoO3 perovskite composite oxide catalyst synthesized by sol-gel method is superior to that synthesized by solid state reaction method, having lower ignition tem-perature of the diesel soot particulates, lower start temperature of NO x treatment, and lower concentration of byproduct CO.

  13. NOx Control Options and Integration for US Coal Fired Boilers

    Energy Technology Data Exchange (ETDEWEB)

    Mike Bockelie; Marc Cremer; Kevin Davis; Martin Denison; Adel Sarofim; Connie Senior; Hong-Shig Shim; Dave Swenson; Bob Hurt; Eric Suuberg; Eric Eddings; Kevin Whitty; Larry Baxter; Calvin Bartholomew; William Hecker

    2006-06-30

    This is the Final Report for DOE Cooperative Agreement No: DE-FC26-00NT40753. The goal of the project was to develop cost-effective analysis tools and techniques for demonstrating and evaluating low-NOx control strategies and their possible impact on boiler performance for boilers firing US coals. The Electric Power Research Institute (EPRI) provided co-funding for this program. This project included research on: (1) In furnace NOx control; (2) Impacts of combustion modifications on boiler operation; (3) Selective Catalytic Reduction (SCR) catalyst testing and (4) Ammonia adsorption/removal on fly ash. Important accomplishments were achieved in all aspects of the project. Rich Reagent Injection (RRI), an in-furnace NOx reduction strategy based on injecting urea or anhydrous ammonia into fuel rich regions in the lower furnace, was evaluated for cyclone-barrel and PC fired utility boilers. Field tests successfully demonstrated the ability of the RRI process to significantly reduce NOx emissions from a staged cyclone-fired furnace operating with overfire air. The field tests also verified the accuracy of the Computational Fluid Dynamic (CFD) modeling used to develop the RRI design and highlighted the importance of using CFD modeling to properly locate and configure the reagent injectors within the furnace. Low NOx firing conditions can adversely impact boiler operation due to increased waterwall wastage (corrosion) and increased soot production. A corrosion monitoring system that uses electrochemical noise (ECN) corrosion probes to monitor, on a real-time basis, high temperature corrosion events within the boiler was evaluated. Field tests were successfully conducted at two plants. The Ohio Coal Development Office provided financial assistance to perform the field tests. To investigate soot behavior, an advanced model to predict soot production and destruction was implemented into an existing reacting CFD modeling tool. Comparisons between experimental data collected

  14. Research Progress on Removal of NO_x following Complex in Aquesus Solution%液相络合法脱除NO_x的研究进展

    Institute of Scientific and Technical Information of China (English)

    钟少芬; 蔡卓弟

    2012-01-01

    "十二五"国家第一次将氮氧化物和氨氮列入约束性指标,排放标准日趋严格,如何经济有效地控制NOX的排放量是我国乃至世界节能减排领域急需解决的关健问题。文章综述了国内外目前开发的液相络合脱除NOX的研究进展,重点分析了亚铁络合剂和钴络合剂脱硝机理,对研究和应用提出了展望。%Nitrogen oxides and ammonia nitrogen were first time listed in the binding index by country for 12th five-year plan.The effluent standard of NOx is strict day by day,the key issue to be soluted urgently is how to effectively,economically control NOx emission to meet energy-saving and emission reduction objective at home and abroad.The development of denitrogenation technologies following complex in aqueous solution over worldwide was summarized.The mechanism of denitrification by ferrous chelates solution and cobalt chelates solution were studied in detail.And the research and application of denitrogenation technologies in aqueous solution was prospected.

  15. Nitrogen Isotope Composition of Thermally Produced NOx from Various Fossil-Fuel Combustion Sources.

    Science.gov (United States)

    Walters, Wendell W; Tharp, Bruce D; Fang, Huan; Kozak, Brian J; Michalski, Greg

    2015-10-01

    The nitrogen stable isotope composition of NOx (δ(15)N-NOx) may be a useful indicator for NOx source partitioning, which would help constrain NOx source contributions in nitrogen deposition studies. However, there is large uncertainty in the δ(15)N-NOx values for anthropogenic sources other than on-road vehicles and coal-fired energy generating units. To this end, this study presents a broad analysis of δ(15)N-NOx from several fossil-fuel combustion sources that includes: airplanes, gasoline-powered vehicles not equipped with a three-way catalytic converter, lawn equipment, utility vehicles, urban buses, semitrucks, residential gas furnaces, and natural-gas-fired power plants. A relatively large range of δ(15)N-NOx values was measured from -28.1‰ to 8.5‰ for individual exhaust/flue samples that generally tended to be negative due to the kinetic isotope effect associated with thermal NOx production. A negative correlation between NOx concentrations and δ(15)N-NOx for fossil-fuel combustion sources equipped with selective catalytic reducers was observed, suggesting that the catalytic reduction of NOx increases δ(15)N-NOx values relative to the NOx produced through fossil-fuel combustion processes. Combining the δ(15)N-NOx measured in this study with previous published values, a δ(15)N-NOx regional and seasonal isoscape was constructed for the contiguous U.S., which demonstrates seasonal and regional importance of various NOx sources. PMID:26332865

  16. Commercial introduction of the Advanced NOxTECH system

    Energy Technology Data Exchange (ETDEWEB)

    Sudduth, B.C. [NOxTECH, Inc., Irvine, CA (United States)

    1997-12-31

    NOxTECH is BACT for diesel electric generators. Emissions of NO{sub x} are reduced 95% or more with substantial concurrent reductions in CO, particulates, and ROG`s. No engine modifications or other exhaust aftertreatments can remove all criteria pollutants as effectively as NOxTECH. The NOxTECH system reliably maintains NH{sub 3} slip below 2 ppm. Unlike other emissions controls, NOxTECH does not generate hazardous by-products. The Advanced NOxTECH system reduces the size, weight, and cost for BACT emissions reductions. Based on the operation of a 150 kW prototype, NOxTECH, Inc. is quoting commercial units for diesel electric generators. Advanced NOxTECH equipment costs about half as much as SCR systems, and NO{sub x} reduction can exceed 95% with guarantees for emissions compliance.

  17. Removal of Mn{sup 2+} from water by 'aged' biofilter media: The role of catalytic oxides layers

    Energy Technology Data Exchange (ETDEWEB)

    Sahabi, D.M.; Takeda, M.; Suzuki, I.; Koizurni, J. [Yokohama National University, Kanagawa (Japan). Dept. of Chemical & Energy Engineering

    2009-02-15

    The present work was aimed at evaluating the surface coatings characteristics and autocatalytic manganese oxidation potentials of two groups of 'aged' biofilter media. This refers to the anthracite filter media of a biological water treatment plant on which metal oxides and a biofilm have deposited on the surface of the filter media over long time of filtration. Duplicate samples of anthracite filter media were collected from each of the six filter wells in the plant and classified into two groups, based on their duration of operation, as 3-years filter media and 15-years filter media. Batch experiments showed that the 15-years filter media exhibited very high manganese sorption capacity and were less dependent on the microbial activity than the 3-years filter media. Results of the surface coatings analyses indicated that the biofilter materials is predominantly composed of variable layers of manganese and iron oxides, with microbial biomass contributing only about 3.5 and 1.4% of the dry weight of the surface coatings on the 3- and 15-years filter media respectively. Investigations onto the Mn{sup 2+} sorption by the lyophilized biofilter media showed that, the sorption kinetics on the catalytic oxides layers followed the pseudo-second-order kinetics model, thus suggesting chemisorption as the dominant mechanism of Mn{sup 2+} removal. This implied that manganese removal by these biofilters is mainly by adsorption of Mn{sup 2+} onto the iron and manganese (catalytic) oxides layers and autocatalytic oxidation. The present study has clearly linked MN{sub 2}+ oxidation to the catalytic oxides layers on the aged biofilter media.

  18. Process for catalytic flue gas denoxing

    International Nuclear Information System (INIS)

    With the increasing concern for the environment, stringency of legislation and industry's awareness of its own environmental responsibility, the demand for the reduction of emission levels of nitrogen oxides is becoming increasingly urgent. This paper reports that Shell has developed a low temperature catalytic deNOx system for deep removal of nitrogen oxides, which includes a low-pressure-drop reactor. This process is able to achieve over 90% removal of nitrogen oxides and therefore can be expected to meet legislation requirements for the coming years. The development of a low-temperature catalyst makes it possible to operate at temperatures as low as 120 degrees C, compared to 300-400 degrees C for the conventional honeycomb and plate-type catalysts. This allows an add-on construction, which is most often a more economical solution than the retrofits in the hot section required with conventional deNOx catalysts. The Lateral Flow Reactor (LFR), which is used for dust-free flue gas applications, and the Parallel Passage Reactor (PPR) for dust-containing flue gas applications, have been developed to work with pressure drops below 10 mbar

  19. 40 CFR 75.19 - Optional SO2, NOX, and CO2 emissions calculation for low mass emissions (LME) units.

    Science.gov (United States)

    2010-07-01

    ... for units equipped with SCR or SNCR), or, consistent with paragraph (c)(1)(iv)(C)(4) of this section, for a unit that uses SCR or SNCR to control NOX emissions, an estimated default NOX emission rate of 0... units that use selective catalytic reduction (SCR) or selective non-catalytic reduction (SNCR)...

  20. Characteristics of NOx emission from Chinese coal-fired power plants equipped with new technologies

    Science.gov (United States)

    Ma, Zizhen; Deng, Jianguo; Li, Zhen; Li, Qing; Zhao, Ping; Wang, Liguo; Sun, Yezhu; Zheng, Hongxian; Pan, Li; Zhao, Shun; Jiang, Jingkun; Wang, Shuxiao; Duan, Lei

    2016-04-01

    Coal combustion in coal-fired power plants is one of the important anthropogenic NOx sources, especially in China. Many policies and methods aiming at reducing pollutants, such as increasing installed capacity and installing air pollution control devices (APCDs), especially selective catalytic reduction (SCR) units, could alter NOx emission characteristics (NOx concentration, NO2/NOx ratio, and NOx emission factor). This study reported the NOx characteristics of eight new coal-fired power-generating units with different boiler patterns, installed capacities, operating loads, and coal types. The results showed that larger units produced less NOx, and anthracite combustion generated more NOx than bitumite and lignite combustion. During formation, the NOx emission factors varied from 1.81 to 6.14 g/kg, much lower than those of older units at similar scales. This implies that NOx emissions of current and future units could be overestimated if they are based on outdated emission factors. In addition, APCDs, especially SCR, greatly decreased NOx emissions, but increased NO2/NOx ratios. Regardless, the NO2/NOx ratios were lower than 5%, in accordance with the guidelines and supporting the current method for calculating NOx emissions from coal-fired power plants that ignore NO2.

  1. Optical and Electronic NOx Sensors for Applications in Mechatronics

    OpenAIRE

    Scott D. Wolter; Garcia, Michael A.; Maria Losurdo; Giovanni Bruno; Luisa Torsi; Nicola Cioffi; Eliana Ieva; Pietro Mario Lugarà; Gaetano Scamarcio; Vincenzo Spagnolo; Angela Elia; Cinzia Di Franco; April Brown; Mario Ricco

    2009-01-01

    Current production and emerging NOx sensors based on optical and nanomaterials technologies are reviewed. In view of their potential applications in mechatronics, we compared the performance of: i) Quantum cascade lasers (QCL) based photoacoustic (PA) systems; ii) gold nanoparticles as catalytically active materials in field-effect transistor (FET) sensors, and iii) functionalized III-V semiconductor based devices. QCL-based PA sensors for NOx show a detection limit in the sub part-per-millio...

  2. HERFD-XANES and XES as complementary operando tools for monitoring the structure of Cu-based zeolite catalysts during NOx-removal by ammonia SCR

    Science.gov (United States)

    Günter, T.; Doronkin, D. E.; Carvalho, H. W. P.; Casapu, M.; Grunwaldt, J.-D.

    2016-05-01

    In this article, we demonstrate the potential of hard X-ray techniques to characterize catalysts under working conditions. Operando high energy resolution fluorescence detected (HERFD) XANES and valence to core (vtc) X-ray emission spectroscopy (XES) have been used in a spatially-resolved manner to study Cu-zeolite catalysts during the standard-SCR reaction and related model conditions. The results show a gradient in Cu oxidation state and coordination along the catalyst bed as the reactants are consumed. Vtc-XES gives complementary information on the direct adsorption of ammonia at the Cu sites. The structural information on the catalyst shows the suitability of X-ray techniques to understand catalytic reactions and to facilitate catalyst optimization.

  3. Reburning technology - a means to reduce NOx emissions

    International Nuclear Information System (INIS)

    Nitrogen oxide emission control technologies can be classified as either combustion modifications to minimize the NO production or post-combustion flue gas treatment to reduce the NO concentration afterwards. The techniques for minimizing NOx Production includes the use of low-NOx burners, overfire air (staged combustion) and boiler combustion optimization. Procedures for flue gas treatment can be subdivided into selective catalytic reduction (SCR) or selective non-catalytic reduction (SNCR). The re burning process is a selective non-catalytic technology which is applicable to a wide variety of boilers and can be implemented within a relatively short period of time. The NOx reduction potential of this technique is in the range of 50 % up to 70 %. (author)

  4. Carbon and nitrogen removal from glucose-glycine melanoidins solution as a model of distillery wastewater by catalytic wet air oxidation.

    Science.gov (United States)

    Phuong Thu, Le; Michèle, Besson

    2016-06-01

    Sugarcane molasses distillery wastewater contains melanoidins, which are dark brown recalcitrant nitrogenous polymer compounds. Studies were carried out in batch mode to evaluate Pt and Ru supported catalysts in the Catalytic Wet Air Oxidation (CWAO) process of a synthetic melanoidins solution, prepared by stoichiometric reaction of glucose with glycine. The addition of a catalyst slightly improved TOC removal compared with the non-catalytic reaction, and especially promoted the conversion of ammonium produced from organically-bound nitrogen in melanoidins to molecular nitrogen and nitrate. The selectivity to N2 attained 89% in the presence of the Pt catalysts in the reaction conditions used (TOC=2200mgL(-1), TN=280mgL(-1), 0.5g catalyst loaded with 3% metal, 210°C, 70bar total air pressure). To avoid leaching of the active metal by organically-bound nitrogen, the reaction was very efficiently performed in a two-step reaction consisting in WAO to convert nitrogen into ammonium, before the introduction of a catalyst. PMID:26900982

  5. Adsorptive removal of lead and cadmium ions using Cross -linked CMC Schiff base: Isotherm, Kinetics and Catalytic Activity

    OpenAIRE

    P.Moganavally; Deepa, M; P.N. SUDHA; Suresh, R.

    2016-01-01

    Water plays a vital role to human and other living organisms. Due to the effluent coming from chemical industries, the industrial activity, contamination of ground water level is goes on increasing nowadays. Therefore, there is a need to develop technologies that can remove toxic pollutants in wastewater. Hence the cross linked Carboxymethyl chitosan(CMC)/ 2,3-dimethoxy Benzaldehyde Schiff base complex has been synthesized and characterized by using FT-IR and SEM analysis. All these results...

  6. One-step hydrothermal synthesis of Cu-SAPO-34/cordierite and its catalytic performance on NO x removal from diesel vehicles%Cu-SAPO-34/堇青石的原位制备及其催化脱除柴油机车尾气中NO x

    Institute of Scientific and Technical Information of China (English)

    王建成; 陈影; 唐磊; 鲍卫仁; 常丽萍; 韩丽娜

    2013-01-01

    Cu-SAPO-34/cordierite catalysts were prepared via one-step hydrothermal synthesis method and their performances to remove NO x from the diesel vehicle exhaust were evaluated. The morphology, structure, Cu content and valence state were characterized by SEM, XRD, ICP and XPS, respectively. The experimental results show the active component Cu of the catalysts via in situ synthesis could significantly improve the selective catalytic reduction (SCR) activities of NOx and the optimal Cu content is in the range of 0.30%-0.40%(mass fraction). No N 2 O is detected by gas chromatograph (GC) during the evaluation process, which implies that NOx is almost entirely converted to N2 over Cu-SAPO-34/cordierite catalyst. The conversion rate of NOx to N2 by NH3 over catalyst could almost be up to 100%in the temperature range of 300-670 °C with a space velocity of 12000 h-1 and it is still more than 60% at 300-620 °C under 36000 h-1. The catalysts also show the good hydrothermal and chemical stability at the atmosphere with H 2 O.%利用水热合成技术将Cu-SAPO-34分子筛直接合成到蜂窝状堇青石上,研究模拟柴油机车尾气中选择性催化还原NO x的能力。采用SEM、XRD、ICP和XPS表征整体式催化剂的形貌、结构、Cu含量和价态变化。结果表明:原位制备技术制备的Cu-SAPO-34/堇青石整体催化剂中的活性金属Cu具有很高的选择性催化还原NO x的活性,Cu的最佳上载量质量分数为0.30%~0.40%。在12000 h-1的体积空速下,在400~670°C之间,可将大部分的NO x催化还原成N 2;在36000 h-1的空速下,在300~620°C之间,还能将60%的NO x转化成N 2。水热老化后的催化剂较好的保持催化活性,表明催化剂具有较好的水热稳定性。

  7. Redox regulation of Nox proteins

    OpenAIRE

    Pendyala, Srikanth; Natarajan, Viswanathan

    2010-01-01

    The generation of reactive oxygen species (ROS) plays a major role in endothelial signaling and function. Of the several potential sources of ROS in the vasculature, the endothelial NADPH Oxidase (Nox) family of proteins, Nox1, Nox2, Nox4 and Nox5, are major contributors of ROS. Excess generation of ROS contributes to the development and progression of vascular disease. While hyperoxia stimulates ROS production through Nox proteins, hypoxia appears to involve mitochondrial electron transport ...

  8. Driftsstudie av Lav NOx brennerteknologi

    OpenAIRE

    Skarbø, Kjartan Juul

    2013-01-01

    NOx dannelsen i forbrenning er en komplisert prosess. Den kan bli kategorisert i tre mekanismer; termisk NOx, hurtig NOx og NOx fra nitrogenforbindelser i drivstoffet. Betydning av mekanismene i denne rapporten er henholdsvis. Forbrenning av hydrogen gir høyere flammetemperaturer som igjen kan føre til mer produksjon av termisk NOx. En lav-NOx brenner utviklet av SINTEF er testet for forskjellige blandinger av metan og hydrogen gass. Fem uavhengige operasjonsfaktorer er undersø...

  9. Preparation of Fe-Mo/ZSM-5 honeycomb catalyst and its performance for catalytic reduction of NOx%蜂窝状Fe-Mo/ZSM-5催化剂制备及其对NOx催化还原性能的影响

    Institute of Scientific and Technical Information of China (English)

    娄晓荣; 李伟; 李哲

    2012-01-01

    以具有较低热膨胀系数和较好抗热冲击性的堇青石蜂窝状陶瓷为载体、Fe-Mo/ZSM-5为活性组分制备了蜂窝状催化剂,研究了表面活性剂、载体和涂覆方法等条件对蜂窝状催化剂性能及其催化活性的影响.采用XRD、FT-IR、BET和SEM等技术对蜂窝状催化剂的体相结构、表面离子形态等进行了表征和研究.结果表明,以羧甲基纤维素为表面活性剂、美国康宁公司的堇青石蜂窝状陶瓷为载体和超声波法涂覆的蜂窝状催化剂具有最佳的催化活性,300℃时NOx催化转化率达100%,且随着温度的升高保持不变.%A series of monolithic catalysts supported with Fe-Mo/ZSM-5 and based on cordierite honeycomb ceramic substrate were prepared and tested for selective catalytic reduction of NOx with NH3. The effects of surface active agent, substrate and coating methods on the SCR activity of monolithic catalysts were investigated simultaneously. The bulk structures and the surface ionic forms of these catalysts were also characterized by XRD, FT-IR, BET and SEM technologies. The results indicated that the monolithic catalyst, prepared with carboxymethyl cellulose as the surface active agent and Corning cordierite honeycomb ceramics as the substrate by ultrasonic method, exhibited the best catalytic activity, and NOx conversion rate over the catalyst reached 100% at 300 ℃.

  10. Nature of nitrogen specie in coke and their role in NOx formation during FCC catalyst regeneration.

    NARCIS (Netherlands)

    Babich, I.V.; Seshan, K.; Lefferts, L.

    2005-01-01

    NOx emission during the regeneration of coked fluid catalytic cracking (FCC) catalysts is an environmental problem. In order to follow the route to NOx formation and try to find ways to suppress it, a coked industrial FCC catalyst has been prepared using model N-containing compounds, e.g., pyridine,

  11. Effect of support on a catalytic converter for removing CO and HC emissions from a two-stroke motorcycle

    Energy Technology Data Exchange (ETDEWEB)

    Lee, C.H.; Chen, Y.W. [National Central Univ., Chungli (Taiwan, Province of China). Dept. of Chemical Engineering

    1997-12-01

    The effect of support on the noble metal catalysts for carbon monoxide and hydrocarbon oxidation was investigated. The reactions were performed under the stoichiometric and oxygen-deficient conditions. Under the stoichiometric point, the activities of the powder catalysts for CO and C{sub 3}H{sub 6} oxidation are in the order Pt/K{sub 2}O/Al{sub 2}O{sub 3} > Pt/Al{sub 2}O{sub 3} > Pt/Al{sub 2}O{sub 3}-SiO{sub 2}, that is, the same as the order of basicity of these catalysts. Under an oxygen-deficient condition, Pt supported on an acidic support, Al{sub 2}O{sub 3}-SiO{sub 2}, exhibits the higher C{sub 3}H{sub 6} conversion and the higher activity for the steam re-forming reaction. In contrast, Pt supported on a basic support, K{sub 2}O/Al{sub 2}O{sub 3}, exhibits the higher CO conversion and the higher activity for the water-gas shift reaction. The order of activity of the powder catalysts for the water-gas shift reaction is the same as the order of basicity of these catalysts. On the other hand, the testing results of the monolithic PtRh-containing catalysts by the simulative gases and the ECE-40 mode driving cycle also reveal the same trend as that of the Pt powder catalysts. Furthermore, the addition of K{sub 2}O on PtRh/Al{sub 2}O{sub 3}-CeO{sub 2} not only increases the basicity of the catalyst but also significantly reduces the CO emission under the ECE-40 mode driving cycle test. Therefore, K{sub 2}O could be a promising additive to a catalytic converter of a two-stroke motorcycle since it can significantly enhance CO conversion.

  12. NOx emissions in China: historical trends and future perspectives

    Directory of Open Access Journals (Sweden)

    B. Zhao

    2013-06-01

    Full Text Available Nitrogen oxides (NOx are key pollutants for the improvement of ambient air quality. Within this study we estimated the historical NOx emissions in China for the period 1995–2010, and calculated future NOx emissions every five years until 2030 under six emission scenarios. Driven by the fast growth of energy consumption, we estimate the NOx emissions in China increased rapidly from 11.0 Mt in 1995 to 26.1 Mt in 2010. Power plants, industry and transportation were major sources of NOx emissions, accounting for 28.4, 34.0, and 25.4% of the total NOx emissions in 2010, respectively. Two energy scenarios, a business as usual scenario (BAU and an alternative policy scenario (PC, were developed to project future energy consumption. In 2030, total energy consumption is projected to increase by 64 and 27% from 2010 level respectively. Three sets of end-of-pipe pollution control measures, including baseline, progressive, and stringent control case, were developed for each energy scenario, thereby constituting six emission scenarios. By 2030, the total NOx emissions are projected to increase (compared to 2010 by 36% in the baseline while policy cases result in reduction up to 61% in the most ambitious case with stringent control measures. More than a third of the reduction achieved by 2030 between least and most ambitious scenario comes from power sector and more than half is distributed equally between industry and transportation sectors. Selective Catalytic Reduction dominates the NOx emission reductions in power plants, while life style changes, control measures for industrial boilers and cement production are major contributors to reductions in industry. Timely enforcement of legislation on heavy duty vehicles would contribute significantly to NOx emission reductions. About 30% of the NOx emission reduction in 2020, and 40% of the NOx emission reduction in 2030 could be treated as the ancillary benefit of energy conservation. Sensitivity analysis was

  13. NOx emissions in China: historical trends and future perspectives

    Science.gov (United States)

    Zhao, B.; Wang, S. X.; Liu, H.; Xu, J. Y.; Fu, K.; Klimont, Z.; Hao, J. M.; He, K. B.; Cofala, J.; Amann, M.

    2013-10-01

    Nitrogen oxides (NOx) are key pollutants for the improvement of ambient air quality. Within this study we estimated the historical NOx emissions in China for the period 1995-2010, and calculated future NOx emissions every five years until 2030 under six emission scenarios. Driven by the fast growth of energy consumption, we estimate the NOx emissions in China increased rapidly from 11.0 Mt in 1995 to 26.1 Mt in 2010. Power plants, industry and transportation were major sources of NOx emissions, accounting for 28.4%, 34.0%, and 25.4% of the total NOx emissions in 2010, respectively. Two energy scenarios, a business as usual scenario (BAU) and an alternative policy scenario (PC), were developed to project future energy consumption. In 2030, total energy consumption is projected to increase by 64% and 27% from 2010 level respectively. Three sets of end-of-pipe pollution control measures, including baseline, progressive, and stringent control case, were developed for each energy scenario, thereby constituting six emission scenarios. By 2030, the total NOx emissions are projected to increase (compared to 2010) by 36% in the baseline while policy cases result in reduction up to 61% in the most ambitious case with stringent control measures. More than a third of the reduction achieved by 2030 between least and most ambitious scenario comes from power sector, and more than half is distributed equally between industry and transportation sectors. Selective catalytic reduction dominates the NOx emission reductions in power plants, while life style changes, control measures for industrial boilers and cement production are major contributors to reductions in industry. Timely enforcement of legislation on heavy-duty vehicles would contribute significantly to NOx emission reductions. About 30% of the NOx emission reduction in 2020 and 40% of the NOx emission reduction in 2030 could be treated as the ancillary benefit of energy conservation. Sensitivity analysis was conducted to

  14. MS title: Catalytic oxidation and removal of arsenite in the presence of Fe ions and zero-valent Al metals.

    Science.gov (United States)

    Hsu, Liang-Ching; Chen, Kai-Yue; Chan, Ya-Ting; Deng, Youjun; Hwang, Che-En; Liu, Yu-Ting; Wang, Shan-Li; Kuan, Wen-Hui; Tzou, Yu-Min

    2016-11-01

    Arsenic immobilization in acid mine drainage (AMD) is required prior to its discharge to safeguard aquatic organisms. Zero-valent aluminum (ZVAl) such as aluminum beverage cans (AlBC) was used to induce the oxidation of As(III) to As(V) and enhance the subsequent As removal from an artificially prepared AMD. While indiscernible As(III) oxidation was found in aerated ZVAl systems, the addition of 0.10-0.55mM Fe(II) or Fe(III) into the AMD significantly promoted the As(V) production. Reactions between Fe(II) and H2O2, which was produced through an oxidative reaction of ZVAl with dissolved oxygen, generated OH radicals. Such OH radicals subsequently induced the As(III) oxidation. Over the course of the Fenton like reaction, ZVAl not only directly generated the H2O2, but indirectly enhanced the OH radical production by replenishing Fe(II). Arsenite oxidation in the aerated ZVAl/Fe and AlBC/Fe systems followed zero- and first-order kinetics. Differences in the kinetic reactions of ZVAl and AlBC with respect to As(III) oxidation were attributed to higher productive efficiency of the oxidant in the AlBC systems. After the completion of As(III) oxidation, As(V) could be removed simultaneously with Al(III) and Fe(III) by increasing solution's pH to 6 to produce Al/Fe hydroxides as As(V) scavengers or to form Al/Fe/As co-precipitates. PMID:27285595

  15. Deactivation-resistant catalyst for selective catalyst reduction of NOx

    OpenAIRE

    Jensen, Anker Degn; Castellino, Francesco; Rams, Per Donskov; Pedersen, Jannik Blaabjerg; Putluru, Siva Sankar Reddy

    2011-01-01

    The present invention relates to a catalyst for selective catalytic reduction of NOx in alkali metal containing flue gas using ammonia as reductant, the catalyst comprising a surface with catalytically active sites, wherein the surface is at least partly coated with a coating comprising at least one metal oxide. In another aspect the present invention relates to the use of said catalyst and to a method of producing said catalyst. In addition, the present invention relates to a method of treat...

  16. Nox2 B-loop Peptide, Nox2ds, Specifically Inhibits Nox2 Oxidase

    OpenAIRE

    Csányi, Gábor; Cifuentes-Pagano, Eugenia; Ghouleh, Imad Al; Ranayhossaini, Daniel J.; Egaña, Loreto; Lopes, Lucia R.; Jackson, Heather M.; Kelley, Eric E.; Pagano, Patrick J.

    2011-01-01

    In recent years, reactive oxygen species (ROS) derived from the vascular isoforms of NADPH oxidase, Nox1, Nox2 and Nox4, have been implicated in many cardiovascular pathologies. As a result, the selective inhibition of these isoforms is an area of intense current investigation. In the present study, we postulated that Nox2ds, a peptidic inhibitor that mimics a sequence in the cytosolic B loop of Nox2, would inhibit ROS production by Nox2-, but not by Nox1- and Nox4-oxidase systems. To test ou...

  17. NOx, SO{sub 3} in the spotlight at NETL's 2006 Environmental Controls conference

    Energy Technology Data Exchange (ETDEWEB)

    Mann, A.N.; Makovsky, L.E.; Sarkus, T.A. [Technology and Management Services Inc. (United States)

    2007-02-15

    As emissions caps drop, technological solutions must become increasingly effective and efficient. Researchers, equipment vendors, and plant operators are exploring alternatives to SCR and SNCR, with a view to reducing the overall costs of NOx reduction. They have also achieved 95% to 99% removal of SO{sub 3}, with no visible plume opacity. These topics were discussed at ECC 2006. The first conference session focussed on selective catalytic reduction (SCR) and selective non-catalytic reduction (SNCR) control of nitrogen oxide emissions; the second session addressed the related issue of reducing stack emissions and flue gas concentrations of sulfur trioxide. The article summarises many papers presented. Summaries and/or full versions of all the papers mentioned, and others, are posted at www.netl.doe.gov/publications/proceedings/06/ecc/index.html. 2 figs.

  18. deNOx catalysts for biomass combustion

    OpenAIRE

    Kristensen, Steffen Buus; Riisager, Anders; Fehrmann, Rasmus; Nørklit Jensen, Jørgen

    2013-01-01

    The present thesis revolves around the challenges involved in removal of nitrogen oxides in biomass fired power plants. Nitrogen oxides are unwanted byproducts formed to some extent during almost any combustion. In coal fired plants these byproducts are removed by selective catalytic reduction, however the alkali in biomass complicate matters. Alkali in biomass severely deactivates the catalyst used for the selective catalytic reduction in matter of weeks,hence a more alkali resistant catalys...

  19. NOx Reduction Technology in Diesel Engine Exhaust by the Plasmatron

    International Nuclear Information System (INIS)

    completeness of the partial fuel oxidation reaction up to 100%. Nitrogen was found to be the most effective gas for the synthesis gas production by a plasmatron. The preliminary experiments of introducing the reformation products into a diesel engine resulted in ∼25% NOx cut in the exhaust gas flow. A simulation experiment with the pure hydrogen addition to the inlet of a diesel engine showed that both components of the synthesis gas H2 and CO fed into the engine play significant role in cutting NOx content in the engine's emission. The selective catalytic reduction (SCR) with propylene and decane as reductants in the presence of excess air over (Fe, Co-Pt)/ZSM-5 catalyst was conducted to remove NOx from Diesel exhaust gases. The SO2 effect and deactivation test over above catalyst were also executed. ZSM-5 supported Co, Pt, Fe mixed oxide catalyst showed about 80% of conversion in the presence of NO. However, the activity was decreased when the catalyst was wash coated onto the ceramic monolith. We found that the deNOx activity over the catalyst was strongly depended on the amount of reductant. Therefore, the amount reductant and how to feed the reductant into the system should be considered as important factors to remove NOx. In order to develop the high removal NOx activity at low temperature and maintain the stable activity at the real exhaust gases condition, metallosilicate and Pt/ZSM-5 catalysts have been used. In case of metallosilicate catalyst, the deNOx activity was low at the oxidation atmospheric condition. When the Pt was ion-exchanged with ZSM-5, the H-form of ZSM-5 catalyst showed high deNOx activity. The effect of reductant type on deNOx activity exhibited that the olefin system provided more higher activity than octane system. The methane conversion observed in the presence of NO and excess O2 over alumina supported Pt catalyst. In order to improve the activity and durability, the Co metal ion was added. The result showed that the Co-Pt catalyst gave high

  20. NOx trade. Case studies

    International Nuclear Information System (INIS)

    Some of the questions with respect to the trade of nitrogen oxides that businesses in the Netherlands have to deal with are dealt with: should a business buy or sell rights for NOx emission; which measures must be taken to reduce NOx emission; how much must be invested; and how to deal with uncertainties with regard to prices. Simulations were carried out with the MOSES model to find the answers to those questions. Results of some case studies are presented, focusing on the chemical sector in the Netherlands. Finally, the financial (dis)advantages of NOx trade and the related uncertainties for a single enterprise are discussed

  1. Heteropoly acid promoted catalyst for SCR of NOx with ammonia

    DEFF Research Database (Denmark)

    2012-01-01

    comprising alkali or earth alkali metals. Such gases comprise for example flue gases arising from the burning of biomass, combined biomass and fossil fuel, and from waste incineration units. The process comprises the selective catalytic reduction (SCR) of NOx, such as nitrogen dioxide (NO2) and nitrogen...

  2. Elementary reaction steps of NOx trapping and SOx deactivation of NOx storage reduction catalysts

    International Nuclear Information System (INIS)

    The NOx storage reduction concept offers a promising strategy for exhaust aftertreatment of lean-bum and diesel engines. However, to meet further more stringent emission regulations, the sulfur resistance of these catalysts has to be improved. Therefore, a detailed knowledge of the NOx storage reduction mechanism and the SOx deactivation mechanism is important to achieve suitable catalysts. The aim of this thesis is, therefore, to obtain a fundamental insight in the NOx adsorption/reduction mechanism and the SOx deactivation mechanism occurring on NSR (non-selective reduction) catalysts to be able to structure the complex reaction sequences into specific key elementary steps. In chapter 2 the experimental details employed in this thesis are given. The adsorption and reduction mechanisms of NOx on sodium and barium metal exchanged zeolite Y used as model storage components are elucidated in chapter 3. With this knowledge, a detailed investigation of the mechanism of NOx storage on a commercial NSR catalyst was carried out and discussed in chapter 4. The influence of SO2 on the catalytic performance of the catalyst is explored in chapter 5. The information obtained in Chapter 5 was used for a detailed investigation of the interaction of SOx with the storage and the oxidation/reduction component (Chapter 6). Finally, in Chapter 7 the results of these study are summarized and general conclusions are given

  3. Optical and Electronic NOx Sensors for Applications in Mechatronics

    Directory of Open Access Journals (Sweden)

    Scott D. Wolter

    2009-05-01

    Full Text Available Current production and emerging NOx sensors based on optical and nanomaterials technologies are reviewed. In view of their potential applications in mechatronics, we compared the performance of: i Quantum cascade lasers (QCL based photoacoustic (PA systems; ii gold nanoparticles as catalytically active materials in field-effect transistor (FET sensors, and iii functionalized III-V semiconductor based devices. QCL-based PA sensors for NOx show a detection limit in the sub part-per-million range and are characterized by high selectivity and compact set-up. Electrochemically synthesized gold-nanoparticle FET sensors are able to monitor NOx in a concentration range from 50 to 200 parts per million and are suitable for miniaturization. Porphyrin-functionalized III-V semiconductor materials can be used for the fabrication of a reliable NOx sensor platform characterized by high conductivity, corrosion resistance, and strong surface state coupling.

  4. Influence of humic substances on the removal of pentachlorophenol by a biomimetic catalytic system with a water-soluble iron(III)-porphyrin complex.

    Science.gov (United States)

    Fukushima, Masami; Sawada, Akira; Kawasaki, Mikio; Ichikawa, Hiroyasu; Morimoto, Kengo; Tatsumi, Kenji; Aoyama, Masakazu

    2003-03-01

    To investigate some basic aspects of soil remediation using biomimetic catalysts, the effects of humic substances (HSs) on the removal of xenobiotics, such as pentachlorophenol (PCP), were investigated. The use of a biomimetic catalytic system using tetra(p-sulfophenyl)porphine-iron(III) (Fe(III)-TPPS) and potassium monopersulfate (KHSO5) resulted in the disappearance of PCP, accompanied by dechlorination. In addition, this process was enhanced by the presence of several types of HSs. The degrees of enhancement (% delta(PCP)60) achieved by the presence of HSs from peat and compost soils were larger than those in the presence of other types of HSs (tropical peat, brown forest, and ando soils). In control experiments, no PCP disappearance and dechlorination were observed in the presence of only KHSO5, only Fe(III)-TPPS, or combinations of HSs and either KHSO5 or Fe(III)-TPPS. To better understand the role of added HS in enhancing or inhibiting PCP disappearance, correlations between the chemical parameters of the HSs and % delta(PCP)60 were investigated. The most effective HSs had lower carboxylic acid contents and lower degrees of unsaturation. The carboxylic acid content and degree of unsaturation increase with the extent of humification. Therefore, HSs of a lower degree of humification would be predicted to be more useful in enhancing the disappearance of PCP in an Fe(III)-TPPS/KHSO5 system. PMID:12666937

  5. Designed copper-amine complex as an efficient template for one-pot synthesis of Cu-SSZ-13 zeolite with excellent activity for selective catalytic reduction of NOx by NH3.

    Science.gov (United States)

    Ren, Limin; Zhu, Longfeng; Yang, Chengguang; Chen, Yanmei; Sun, Qi; Zhang, Haiyan; Li, Caijin; Nawaz, Faisal; Meng, Xiangju; Xiao, Feng-Shou

    2011-09-21

    Low-cost copper-amine complex was rationally designed to be a novel template for one-pot synthesis of Cu-SSZ-13 zeolites. Proper confirmation and appropriate size make this complex fit well with CHA cages as an efficient template. The products exhibit superior catalytic performance on NH(3)-SCR reaction. PMID:21625721

  6. Gas Turbines: ''low NOx'' technologies at EGT

    International Nuclear Information System (INIS)

    For more than 15 years, European Gas Turbines (EGT - GEC Alsthom Group) has gained an important know-how culture and can use its rich feedback experience in the domain of gas turbine emissions. The EGT gas turbine units equipped with denitrogenation technologies cover the 4 to 226 MW power range and cumulate more than 1.7 hours of functioning in the different existing installations in the world. This paper describes the economical and environmental interests of gas turbines for power production and the combustion technologies developed by EGT to reduce the NOx emissions. The selective catalytic reduction technique is the only available secondary technique with can allow NOx and CO emissions lower than 10 ppm. Other technologies involving diluent injection (water, water-fuel mixture, vapor..) are also described and were developed in several countries to reduce the emission of these pollutants. (J.S.)

  7. System for Removing Pollutants from Incinerator Exhaust

    Science.gov (United States)

    Wickham, David t.; Bahr, James; Dubovik, Rita; Gebhard, Steven C.; Lind, Jeffrey

    2008-01-01

    A system for removing pollutants -- primarily sulfur dioxide and mixed oxides of nitrogen (NOx) -- from incinerator exhaust has been demonstrated. The system is also designed secondarily to remove particles, hydrocarbons, and CO. The system is intended for use in an enclosed environment, for which a prior NOx-and-SO2-removal system designed for industrial settings would not be suitable.

  8. Catalytic Performance of Fe/H-beta Catalyst Modified by Mn for NOx Decomposition at Low Temperature%Mn改性Fe/H-beta催化剂的低温催化分解NOx的研究

    Institute of Scientific and Technical Information of China (English)

    潘华; 宋华丰

    2012-01-01

    通过Mn改性制备了Fe和Mn的质量比为1且Fe和Mn的质量分数均为5% (5%Fe-5%Mn/H-beta)的催化剂,通过氢气程序升温还原(H2-TPR)比较分析了Fe-Mn/H-beta、Fe/H-beta和Mn/H-beta催化剂中Fe和Mn的化学形态,考察了O2、SO2和H2O等反应条件对Fe-Mn/H-beta催化剂低温催化分解NOx的影响.结果表明,相比Fe/H-beta和Mn/H-beta,Fe-Mn/H-beta 催化剂在富氧和低温条件下具有较好的催化活性,其中623 K下催化剂的活性最高,NOx的转化率达到45%左右.Fe-Mn/H-beta催化剂中Fe和Mn的共存提高了Fe2O3和MnO2的含量.氧的存在促进了NOx催化分解,水蒸气和SO2对NOx催化分解有一定的抑制作用.%Direct decomposition of NOX was investigated with 5% Fe-5% Mn/H-beta catalysts with equal weight of Mn and Fe. The chemical states of Fe and Mn in Fe-Mn/H-beta, Fe/H-be-ta, and Mn/H-beta catalysts were characterized by H2-TPR. The effects of O2, SO2 and H20 on decomposition of NOX at low temperature with 5 %Fe-5% Mn/H-beta catalysts were examined. The results indicate that the activity of Fe-Mn/H-beta is higher than that of Fe/H-beta or Mn/H-beta at rich oxygen and low temperature from 573 K to 673 K. The maximum NO* conversion is about 45% with 5 %Fe-5%Mn/H-beta at 623 K. The presence of Fe in Fe-Mn/H-beta enhances the transformation of Mn3+ ions into Mn4+ ions, and the addition of Mn increases the amount of Fe2O3 in Fe-Mn/H-beta. In addition, O2 inhibition is not observed in NOX decomposition with Fe-Mn/H-beta while the presence of H2O and SO2 inhibits the activity of Fe-Mn/H-beta.

  9. System and method for selective catalytic reduction of nitrogen oxides in combustion exhaust gases

    Science.gov (United States)

    Sobolevskiy, Anatoly; Rossin, Joseph A

    2014-04-08

    A multi-stage selective catalytic reduction (SCR) unit (32) provides efficient reduction of NOx and other pollutants from about 50-550.degree. C. in a power plant (19). Hydrogen (24) and ammonia (29) are variably supplied to the SCR unit depending on temperature. An upstream portion (34) of the SCR unit catalyzes NOx+NH.sub.3 reactions above about 200.degree. C. A downstream portion (36) catalyzes NOx+H.sub.2 reactions below about 260.degree. C., and catalyzes oxidation of NH.sub.3, CO, and VOCs with oxygen in the exhaust above about 200.degree. C., efficiently removing NOx and other pollutants over a range of conditions with low slippage of NH.sub.3. An ammonia synthesis unit (28) may be connected to the SCR unit to provide NH.sub.3 as needed, avoiding transport and storage of ammonia or urea at the site. A carbonaceous gasification plant (18) on site may supply hydrogen and nitrogen to the ammonia synthesis unit, and hydrogen to the SCR unit.

  10. NOx Control Options and Integration for US Coal Fired Boilers

    Energy Technology Data Exchange (ETDEWEB)

    Mike Bockelie; Kevin Davis; Temi Linjewile; Connie Senior; Eric Eddings; Kevin Whitty; Larry Baxter; Calvin Bartholomew; William Hecker; Stan Harding; Robert Hurt

    2003-12-31

    This is the fourteenth Quarterly Technical Report for DOE Cooperative Agreement No: DEFC26-00NT40753. The goal of the project is to develop cost effective analysis tools and techniques for demonstrating and evaluating low NOx control strategies and their possible impact on boiler performance for boilers firing US coals. The Electric Power Research Institute (EPRI) is providing co-funding for this program. Using the initial CFD baseline modeling of the Gavin Station and the plant corrosion maps, six boiler locations for the corrosion probes were identified and access ports have been installed. Preliminary corrosion data obtained appear consistent and believable. In situ, spectroscopic experiments at BYU reported in part last quarter were completed. New reactor tubes have been made for BYU's CCR that allow for testing smaller amounts of catalyst and thus increasing space velocity; monolith catalysts have been cut and a small reactor that can accommodate these pieces for testing is in its final stages of construction. A poisoning study on Ca-poisoned catalysts was begun this quarter. A possible site for a biomass co-firing test of the slipstream reactor was visited this quarter. The slipstream reactor at Rockport required repair and refurbishment, and will be re-started in the next quarter. This report describes the final results of an experimental project at Brown University on the fundamentals of ammonia / fly ash interactions with relevance to the operation of advanced NOx control technologies such as selective catalytic reduction. The Brown task focused on the measurement of ammonia adsorption isotherms on commercial fly ash samples subjected to a variety of treatments and on the chemistry of dry and semi-dry ammonia removal processes.

  11. Performance and kinetic study on selective catalytic reduction of NOx with NH3 of MnOx-WO3/TiO2 catalyst%MnOx-WO3/TiO2NH3选择性还原NOx的催化性能与动力学

    Institute of Scientific and Technical Information of China (English)

    吴碧君; 肖萍; 刘晓勤

    2011-01-01

    研究了Mn-W/TiO2用于NH3选择性催化还原NOx体系的催化反应性能,在很宽的温度范围和各种气体条件下,该催化剂显示了较高的催化活性.在GHSV 18900 h-1、100~350℃条件下,NOx转化率高达80.3%~99.6%,Nz选择性达98.7%~100%;当反应气体中有0.01%SO2(分压比,下同)和6%H2O,120℃转化率可维持在98.5%;SO2浓度高达0.07%,300℃转化率可长期稳定在99%,达到了商用V-W/TiO2催化剂的水平.稳态动力学实验发现,O2对Mn-W/TiO2NH3-SCR NOx催化体系起促进作用,O2含量在1.5%以下时转化率随O2浓度的增加而显著提高;当有过量O2和过量H2O存在时,反应为关于NO浓度的一级反应,关于NH3浓度的零级反应.由各温度下的动力学实验结果推导出Mn-W/TiO2催化反应的活化能为6.24 kJ·mol-1,较文献报道的其他催化剂的活化能低得多,为NH3选择性还原NOx较好的催化剂.%The catalytic activities of MnOx-WO3/TiO2 catalyst in a wide temperature range were investigated for selective catalytic reduction (SCR) of NO with NH3.It yields 80.3%-99.6% NOx conversion and 98.7%-100% selectivity for N2 product from 100℃ to 350℃ at GHSV 18900 h-1. In the presence of 0. 01% SO2 and 6% H2O at 120℃, the NOx conversion maintains at 98. 5%. At 300℃ and with 0.07% SO2 in the reactant stream, the NOx conversion is 99%, as high as that of the commercial V-W/ TiO2 catalyst. The steady-state kinetic study shows that O2 plays a promoting role. When O2 content is less than 1.5%, the NOx conversion increases sharply with O2 concentration. The reaction order is zero with respect to NH3 and first with respect to NO with excess O2 and H2O. The active energy of Mn-W/TiO2 calculated is 6.24 kJ · mol-1 according to the kinetic experiments at various temperatures, much lower than other catalysts reported in the literatures. Thus Mn-W/TiO2 is an excellent catalyst for SCR NO with NH3.

  12. Vortex combustor for low NOX emissions when burning lean premixed high hydrogen content fuel

    Science.gov (United States)

    Steele, Robert C; Edmonds, Ryan G; Williams, Joseph T; Baldwin, Stephen P

    2012-11-20

    A trapped vortex combustor. The trapped vortex combustor is configured for receiving a lean premixed gaseous fuel and oxidant stream, where the fuel includes hydrogen gas. The trapped vortex combustor is configured to receive the lean premixed fuel and oxidant stream at a velocity which significantly exceeds combustion flame speed in a selected lean premixed fuel and oxidant mixture. The combustor is configured to operate at relatively high bulk fluid velocities while maintaining stable combustion, and low NOx emissions. The combustor is useful in gas turbines in a process of burning synfuels, as it offers the opportunity to avoid use of diluent gas to reduce combustion temperatures. The combustor also offers the possibility of avoiding the use of selected catalytic reaction units for removal of oxides of nitrogen from combustion gases exiting a gas turbine.

  13. Electrochemical removal of NOx and hydrocarbons

    DEFF Research Database (Denmark)

    Friedberg, Anja Zarah

    This thesis comprise of investigations on an electrochemical cell for the reduction of NO by propene. The focus has been on the electrochemical enhancement of the selective reduction of NO by propene by using perovskites, which are known to be catalyst for this reaction in the composite electrodes......, or to contribute with entirely new properties to the system. The LSM was also tested with cobalt doping in the structure.Two types of electrochemical cells were tested. The simplest one being the symmetrical cell and the other a cell stack of porous alternating layers of electrode and electrolyte. To evaluate...... the systems, conversion measurements has been done where polarisations were applied to the cells during gas analysis. The characterisation of the different materials was done using electrochemical impedance spectroscopy and cyclic voltammetry.This project revealed that the propene acts as an inhibitor...

  14. 尿素、碳酸氢铵/添加剂同时脱硫脱硝试验研究%Experimental investigation on simultaneous removal of SO2 and NOx by solutions of urea and ammonium bicarbonate/additives

    Institute of Scientific and Technical Information of China (English)

    史占飞; 熊源泉; 谢红银; 张吉超

    2011-01-01

    Experimental research of simultaneous removal of NOx and SO2 with aqueous urea and ammonium bicarbonate/additives solution was carried out in a bubbling reactor, where the effects of two different aqueous ( urea and ammonium bicarbonate) on the NOx removal characteristics were investigated. A series of experimentations were carried out to study the effect of operation parameters,such as liquid level, sorbent composition and SO2 concentration. The results show that liquid level,mass ratio of urea and annonium bicarbonate in mixed solution and SO2 concentration have a significant effect on the removal efficiency of NOx. Two absorbents have the highest denitrification efficiency when liquid level reaches 459 mm. Increasing the proportion of ammonium bicarbonate in multiple solvent is unfavorable to NOx removal. The average denitrification efficiency with solution of 5% urea + 5% ammonium bicarbonate/triethanolamine(0. 015% ) reduces by only 9% compared with 10% urea/triethanolamine(0. 015% ), and the removal efficiencies of NOx and SO2 can still reach 63% and 97% respectively, while the costs of absorbent decrease by nearly 30%. The existence of SO2 has synergistic effect on the absorption of NOx, the sulfite ions play reductive role on NOx which make the denitrification efficiencies of two absorbents increase about 3 %.%在鼓泡反应装置上进行了尿素、碳酸氢铵/三乙醇胺溶液同时脱硫脱硝的试验研究,比较尿素和碳酸氢铵的脱硫脱硝性能,试验分别对液位、吸收剂组成以及SO2体积分数等参数对脱硝效率的影响规律进行了研究.结果表明:液位、吸收液中尿素/碳酸氢铵的比例及SO2入口浓度对NOx的脱除效率均有重要的影响,液位在459 mm时2种吸收液的脱硝效率最高;增加多元溶剂中碳酸氢铵质量浓度不利于NOx的脱除,而5%尿素、5%碳酸氢铵/三乙醇胺(0.015%)多元溶剂的脱硝效率仅比10%的尿素/三乙醇胺(0.015%)

  15. Toluene removal by sequential adsorption-plasma catalytic process: Effects of Ag and Mn impregnation sequence on Ag-Mn/γ-Al2O3.

    Science.gov (United States)

    Qin, Caihong; Huang, Xuemin; Dang, Xiaoqing; Huang, Jiayu; Teng, Jingjing; Kang, Zhongli

    2016-11-01

    A series of Ag-Mn/γ-Al2O3 were prepared under different Ag/Mn impregnation sequence and tested in the sequential adsorption-plasma catalytic removal of toluene. When Mn was impregnated first, the resulting catalyst, Ag-Mn(F)/γ-Al2O3, had longer breakthrough time, gave less emission of toluene, had higher CO2 selectivity, and had better carbon balance and COx yield compared to catalysts prepared via other impregnation sequences. After 120 min of NTP treatment, the carbon balance of Ag-Mn(F)/γ-Al2O3 was 91%, with 87% as COx contributions. A Brunauer-Emmett-Teller (BET) analysis and X-ray photoelectron spectroscopy (XPS) results show that, the impregnation sequence impacts the BET surface area and the ratio and existing state of Ag on the surface of the catalysts. The longer breakthrough time when using Ag-Mn(F)/γ-Al2O3 as catalyst is attributed to the large amount of Ag(+) on the surface. Ag(+) is a new active site for toluene adsorption. When Ag was impregnated first (Ag(F)-Mn/γ-Al2O3) or Ag and Mn co-impregnated (Ag-Mn-C/γ-Al2O3), the predominant specie was Ag(+). Both Ag(0) and Ag(+) species were detected on Ag-Mn(F)/γ-Al2O3. Ag(0) cooperation with MnOx may promote the migration of surface active oxygen. This would facilitate the oxidation of adsorbed toluene with CC bond already weakened by Ag(+) and would result in higher CO2 selectivity and better carbon balance as seen in the Ag-Mn(F)/γ-Al2O3 system. PMID:27494312

  16. Enhanced Combustion Low NOx Pulverized Coal Burner

    Energy Technology Data Exchange (ETDEWEB)

    David Towle; Richard Donais; Todd Hellewell; Robert Lewis; Robert Schrecengost

    2007-06-30

    For more than two decades, Alstom Power Inc. (Alstom) has developed a range of low cost, infurnace technologies for NOx emissions control for the domestic U.S. pulverized coal fired boiler market. This includes Alstom's internally developed TFS 2000{trademark} firing system, and various enhancements to it developed in concert with the U.S. Department of Energy. As of the date of this report, more than 270 units representing approximately 80,000 MWe of domestic coal fired capacity have been retrofit with Alstom low NOx technology. Best of class emissions range from 0.18 lb/MMBtu for bituminous coal to 0.10 lb/MMBtu for subbituminous coal, with typical levels at 0.24 lb/MMBtu and 0.13 lb/MMBtu, respectively. Despite these gains, NOx emissions limits in the U.S. continue to ratchet down for new and existing boiler equipment. On March 10, 2005, the Environmental Protection Agency (EPA) announced the Clean Air Interstate Rule (CAIR). CAIR requires 25 Eastern states to reduce NOx emissions from the power generation sector by 1.7 million tons in 2009 and 2.0 million tons by 2015. Low cost solutions to meet such regulations, and in particular those that can avoid the need for a costly selective catalytic reduction system (SCR), provide a strong incentive to continue to improve low NOx firing system technology to meet current and anticipated NOx control regulations. The overall objective of the work is to develop an enhanced combustion, low NOx pulverized coal burner, which, when integrated with Alstom's state-of-the-art, globally air staged low NOx firing systems will provide a means to achieve: Less than 0.15 lb/MMBtu NOx emissions when firing a high volatile Eastern or Western bituminous coal, Less than 0.10 lb/MMBtu NOx emissions when firing a subbituminous coal, NOx reduction costs at least 25% lower than the costs of an SCR, Validation of the NOx control technology developed through large (15 MWt) pilot scale demonstration, and Documentation required for

  17. Molecular evolution of the reactive oxygen-generating NADPH oxidase (Nox/Duox family of enzymes

    Directory of Open Access Journals (Sweden)

    Lambeth J David

    2007-07-01

    Full Text Available Abstract Background NADPH-oxidases (Nox and the related Dual oxidases (Duox play varied biological and pathological roles via regulated generation of reactive oxygen species (ROS. Members of the Nox/Duox family have been identified in a wide variety of organisms, including mammals, nematodes, fruit fly, green plants, fungi, and slime molds; however, little is known about the molecular evolutionary history of these enzymes. Results We assembled and analyzed the deduced amino acid sequences of 101 Nox/Duox orthologs from 25 species, including vertebrates, urochordates, echinoderms, insects, nematodes, fungi, slime mold amoeba, alga and plants. In contrast to ROS defense enzymes, such as superoxide dismutase and catalase that are present in prokaryotes, ROS-generating Nox/Duox orthologs only appeared later in evolution. Molecular taxonomy revealed seven distinct subfamilies of Noxes and Duoxes. The calcium-regulated orthologs representing 4 subfamilies diverged early and are the most widely distributed in biology. Subunit-regulated Noxes represent a second major subdivision, and appeared first in fungi and amoeba. Nox5 was lost in rodents, and Nox3, which functions in the inner ear in gravity perception, emerged the most recently, corresponding to full-time adaptation of vertebrates to land. The sea urchin Strongylocentrotus purpuratus possesses the earliest Nox2 co-ortholog of vertebrate Nox1, 2, and 3, while Nox4 first appeared somewhat later in urochordates. Comparison of evolutionary substitution rates demonstrates that Nox2, the regulatory subunits p47phox and p67phox, and Duox are more stringently conserved in vertebrates than other Noxes and Nox regulatory subunits. Amino acid sequence comparisons identified key catalytic or regulatory regions, as 68 residues were highly conserved among all Nox/Duox orthologs, and 14 of these were identical with those mutated in Nox2 in variants of X-linked chronic granulomatous disease. In addition to

  18. Possibility of Reducing Formations of NOx and SO2 Simultaneously during Coal Combustion

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Comparing with other NOx and SO2 control technologies, in-bed reducing NOx and SO2 simultaneously during coal combustion may lower the investment and operation cost. However, there are several possible contradictions between the reduction of NOx and the capture of SO2 during combustion: 1) CO rich atmosphere is favorable for the reduction of NOx, whereas O2 rich favorable for the capture of SO2; 2) higher preheating temperature of coal is favorable for reducing NOx, but unfavorable for reducing SO2; 3) sulphation of some minerals may deactivate their catalytic effect on the reduction of NOx. The attempts to eliminate such contradictions by coating coal granules with thin layer of monometallic oxides and mixed oxides were proposed. Ni2O3 and Fe2O3 showed high activity on NOx reduction and CaO and Cr2O3 showed good effect on sulfur capture. The mixed metallic oxides, e.g., Fe2O3NiO, etc., showed effective for both NOx reduction and SO2 retention. It is possible to in-bed reduce NOx and SO2 simultaneously if the adhering materials are properly chosen to be difunctional materials of both active catalysts for NOx reduction reactions and better sorbents for SO2 retention.

  19. Oxidation of elemental mercury by modified spent TiO2-based SCR-DeNOx catalysts in simulated coal-fired flue gas.

    Science.gov (United States)

    Zhao, Lingkui; Li, Caiting; Zhang, Xunan; Zeng, Guangming; Zhang, Jie; Xie, Yin'e

    2016-01-01

    In order to reduce the costs, the recycle of spent TiO2-based SCR-DeNOx catalysts were employed as a potential catalytic support material for elemental mercury (Hg(0)) oxidation in simulated coal-fired flue gas. The catalytic mechanism for simultaneous removal of Hg(0) and NO was also investigated. The catalysts were characterized by Brunauer-Emmett-Teller (BET), scanning electron microscope (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) method. Results indicated that spent TiO2-based SCR-DeNOx catalyst supported Ce-Mn mixed oxides catalyst (CeMn/SCR1) was highly active for Hg(0) oxidation at low temperatures. The Ce1.00Mn/SCR1 performed the best catalytic activities, and approximately 92.80% mercury oxidation efficiency was obtained at 150 °C. The inhibition effect of NH3 on Hg(0) oxidation was confirmed in that NH3 consumed the surface oxygen. Moreover, H2O inhibited Hg(0) oxidation while SO2 had a promotional effect with the aid of O2. The XPS results illustrated that the surface oxygen was responsible for Hg(0) oxidation and NO conversion. Besides, the Hg(0) oxidation and NO conversion were thought to be aided by synergistic effect between the manganese and cerium oxides. PMID:26370819

  20. Oxidation of elemental mercury by modified spent TiO2-based SCR-DeNOx catalysts in simulated coal-fired flue gas.

    Science.gov (United States)

    Zhao, Lingkui; Li, Caiting; Zhang, Xunan; Zeng, Guangming; Zhang, Jie; Xie, Yin'e

    2016-01-01

    In order to reduce the costs, the recycle of spent TiO2-based SCR-DeNOx catalysts were employed as a potential catalytic support material for elemental mercury (Hg(0)) oxidation in simulated coal-fired flue gas. The catalytic mechanism for simultaneous removal of Hg(0) and NO was also investigated. The catalysts were characterized by Brunauer-Emmett-Teller (BET), scanning electron microscope (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) method. Results indicated that spent TiO2-based SCR-DeNOx catalyst supported Ce-Mn mixed oxides catalyst (CeMn/SCR1) was highly active for Hg(0) oxidation at low temperatures. The Ce1.00Mn/SCR1 performed the best catalytic activities, and approximately 92.80% mercury oxidation efficiency was obtained at 150 °C. The inhibition effect of NH3 on Hg(0) oxidation was confirmed in that NH3 consumed the surface oxygen. Moreover, H2O inhibited Hg(0) oxidation while SO2 had a promotional effect with the aid of O2. The XPS results illustrated that the surface oxygen was responsible for Hg(0) oxidation and NO conversion. Besides, the Hg(0) oxidation and NO conversion were thought to be aided by synergistic effect between the manganese and cerium oxides.

  1. Selective catalytic reduction of NO by ammonia over oil shale ash and fly ash catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Changtao Yue; Shuyuan Li [University of Petroleum, Beijing (China). State Key Lab of Heavy Oil Processing

    2003-07-01

    Acid rain and urban air pollution, produced mainly by pollutants such as SOX and NOX and other volatile organic compounds, has become the most serious environmental problem. The selective catalytic reduction (SCR) of NO with NH{sub 3} in the presence of oxygen is a wellproven method to limit the NOX emissions. The work in this field has been the subject of much research in recent years. In this paper, NO reduction with NH{sub 3} over oil shale ash or fly ash catalysts was studied. Fe, Cu, V or Ni as active elements was loaded by adding aqueous solutions of the metal nitrate over the oil shale ash or fly ash support. The activities of the catalysts for NO removal were measured in a fixed-bed reactor. According to the results, oil shale ash or fly ash, after pre-treatment, can be reasonably used as the SCR catalyst support to remove NO from flue gas. Cu gave the highest catalytic activity and NO conversion for fly ash while V for oil shale ash. As the support, fly ash is more feasible than oil shale ash. Because of their low cost and high efficiency, the catalysts should be used in the SCR process. Further research on this subject is necessary in the future to understand more details of the SCR system and issue of pollution control. 9 refs., 2 figs., 2 tabs.

  2. Elementary Steps and Site Requirements for NOx Adsorption and Oxidation on Metal and Oxide Surfaces

    OpenAIRE

    Weiss, Brian M.

    2010-01-01

    NO oxidation catalysts are used in conjunction with NOx adsorbents to remove toxic nitrogen oxides from combustion effluents that lack CO and residual hydrocarbons as reductants. Efficient NOx trapping strategies require detailed knowledge of the reaction mechanism and the structural requirements for NO oxidation and for NOx adsorption, which are investigated here by kinetic, isotopic, and spectroscopic methods. NO oxidation rates on Pt, PdO, RhO2, and Co3O4 catalysts increase linearly with O...

  3. Catalytic distillation process

    Science.gov (United States)

    Smith, Jr., Lawrence A.

    1982-01-01

    A method for conducting chemical reactions and fractionation of the reaction mixture comprising feeding reactants to a distillation column reactor into a feed zone and concurrently contacting the reactants with a fixed bed catalytic packing to concurrently carry out the reaction and fractionate the reaction mixture. For example, a method for preparing methyl tertiary butyl ether in high purity from a mixed feed stream of isobutene and normal butene comprising feeding the mixed feed stream to a distillation column reactor into a feed zone at the lower end of a distillation reaction zone, and methanol into the upper end of said distillation reaction zone, which is packed with a properly supported cationic ion exchange resin, contacting the C.sub.4 feed and methanol with the catalytic distillation packing to react methanol and isobutene, and concurrently fractionating the ether from the column below the catalytic zone and removing normal butene overhead above the catalytic zone.

  4. Nox1 is over-expressed in human colon cancers and correlates with activating mutations in K-Ras

    OpenAIRE

    Laurent, Eunice; McCoy, James W.; Macina, Roberto A.; Liu, Wenhui; Cheng, Guangjie; Robine, Sylvie; Papkoff, Jackie; Lambeth, J. David

    2008-01-01

    The NADPH-oxidase 1 (Nox1) is a homolog of gp91phox, the catalytic subunit of the phagocyte superoxide-generating NADPH-oxidase. Nox1 is expressed in normal colon epithelial cells and in colon tumor cell lines, and overexpression in model cells has been implicated in stimulation of mitogenesis and angiogenesis and inhibition of apoptosis. This suggests that aberrant expression of Nox1 could contribute to the development of colorectal cancer. Herein, we examine the expression of Nox1 mRNA in 2...

  5. Alternative deNOx catalysts and technologies

    DEFF Research Database (Denmark)

    Due-Hansen, Johannes

    in the flue gas when biomass is combusted. By co-firing with large amounts of CO2-neutral straw or wood (tomeet stringent CO2 emission legislation), the lifetime of the traditional SCR catalyst is thus significantly reduced due to the presence of deactivating species originating from the fuel. To develop......The present thesis entitled Alternative deNOx Catalysts and technologies revolves around the topic of removal of nitrogen oxides. Nitrogen oxides, NOx, are unwanted byproducts formed during combustion (e.g. in engines or power plants). If emitted to the atmosphere, they are involved...... a catalyst less susceptible to the poisons present in the flue gas, a number of catalysts have been synthesized and tested in the present work, all based on commercially available supports. A highly acidic support consisting of sulfated zirconia was chosen based on preliminary studies. A number of different...

  6. Deactivation-resistant catalyst for selective catalyst reduction of NOx

    DEFF Research Database (Denmark)

    2011-01-01

    The present invention relates to a catalyst for selective catalytic reduction of NOx in alkali metal containing flue gas using ammonia as reductant, the catalyst comprising a surface with catalytically active sites, wherein the surface is at least partly coated with a coating comprising at least...... one metal oxide. In another aspect the present invention relates to the use of said catalyst and to a method of producing said catalyst. In addition, the present invention relates to a method of treating an catalyst for conferring thereon an improved resistance to alkali poisoning....

  7. The Use of Amine Reclaimer Wastes as a NOx Reduction Agent

    DEFF Research Database (Denmark)

    Botheju, Deshai; Glarborg, Peter; Tokheim, Lars-Andre

    2013-01-01

    scale experimental trials carried out in this study using ARW and pure monoethanolamine (MEA) confirmed the possibility of utilizing ARW as a potential reagent for the selective non-catalytic reduction (SNCR) of NOx in combustion flue gases. Even though the effectiveness of ARW is lower than...... that of aqueous ammonia, i.e. the most common SNCR chemical reagent used in industry (above 60% NOx reduction efficiency), ARW is nonetheless shown to possess valuable SNCR qualities (at least 20% NOx reduction efficiency) considering its availability as a waste product which has to be safely disposed. A series...

  8. NOx Abatement Pilot Plant 90-day test results report

    International Nuclear Information System (INIS)

    High-level radioactive liquid wastes produced during nuclear fuel reprocessing at the Idaho Chemical Processing Plant are calcined in the New Waste Calcining Facility (NWCF) to provide both volume reduction and a more stable waste form. Because a large component of the HLW is nitric acid, high levels of oxides of nitrogen (NOx) are produced in the process and discharged to the environment via the calciner off-gas. The NOx abatement program is required by the new Fuel Processing Restoration (FPR) project permit to construct to reduce NOx emissions from the NWCF. Extensive research and development has indicated that the selective catalytic reduction (SCR) process is the most promising technology for treating the NWCF off-gas. Pilot plant tests were performed to determine the compatibility of the SCR process with actual NWCF off-gas. Test results indicate that the SCR process is a viable method for abating the NOx from the NWCF off-gas. Reduction efficiencies over 95% can be obtained, with minimal amounts of ammonia slip, provided favorable operating conditions exist. Two reactors operated with series flow will provide optimum reduction capabilities. Typical operation should be performed with a first reactor stage gas space velocity of 20,000 hr-1 and an inlet temperature of 320 degrees C. The first stage exhaust NOx concentration will then dictate the parameter settings for the second stage. Operation should always strive for a peak reactor temperature of 520 degrees C in both reactors, with minimal NH3 slip from the second reactor. Frequent fluctuations in the NWCF off-gas NOx concentration will require a full-scale reduction facility that is versatile and quick-responding. Sudden changes in NWCF off-gas NOx concentrations will require quick detection and immediate response to avoid reactor bed over-heating and/or excessive ammonia slip

  9. Electro Catalytic Oxidation (ECO) Operation

    Energy Technology Data Exchange (ETDEWEB)

    Morgan Jones

    2011-03-31

    The power industry in the United States is faced with meeting many new regulations to reduce a number of air pollutants including sulfur dioxide, nitrogen oxides, fine particulate matter, and mercury. With over 1,000 power plants in the US, this is a daunting task. In some cases, traditional pollution control technologies such as wet scrubbers and SCRs are not feasible. Powerspan's Electro-Catalytic Oxidation, or ECO{reg_sign} process combines four pollution control devices into a single integrated system that can be installed after a power plant's particulate control device. Besides achieving major reductions in emissions of sulfur dioxide (SO{sub 2}), nitrogen oxides (NOx), fine particulate matter (PM2.5) and mercury (Hg), ECO produces a highly marketable fertilizer, which can help offset the operating costs of the process system. Powerspan has been operating a 50-MW ECO commercial demonstration unit (CDU) at FirstEnergy Corp.'s R.E. Burger Plant near Shadyside, Ohio, since February 2004. In addition to the CDU, a test loop has been constructed beside the CDU to demonstrate higher NOx removal rates and test various scrubber packing types and wet ESP configurations. Furthermore, Powerspan has developed the ECO{reg_sign}{sub 2} technology, a regenerative process that uses a proprietary solvent to capture CO{sub 2} from flue gas. The CO{sub 2} capture takes place after the capture of NOx, SO{sub 2}, mercury, and fine particulate matter. Once the CO{sub 2} is captured, the proprietary solution is regenerated to release CO{sub 2} in a form that is ready for geological storage or beneficial use. Pilot scale testing of ECO{sub 2} began in early 2009 at FirstEnergy's Burger Plant. The ECO{sub 2} pilot unit is designed to process a 1-MW flue gas stream and produce 20 tons of CO{sub 2} per day, achieving a 90% CO{sub 2} capture rate. The ECO{sub 2} pilot program provided the opportunity to confirm process design and cost estimates, and prepare for large

  10. Simulation of Air Quality over Beijing, Tianjin, and Hebei Province of China with Application of Catalysts for Selective Catalytic Reduction of NOx to Diesel Exhaust and Natural Gas Boilers%脱硝技术与天然气应用情景下京津冀地区空气质量模拟评估

    Institute of Scientific and Technical Information of China (English)

    李健; 安俊岭; 陈勇; 屈玉

    2013-01-01

    Three scenarios were designed in which catalysts for selective catalytic reduction (SCR) of NOx were applied to diesel exhaust (Scenario 1), catalysts for SCR were applied to both diesel exhaust and natural gas boilers according to the Chinese energy plan for 2015 (Scenario 2), and the catalysts were applied as in Scenario 2 but the Chinese energy plan for 2030 was used (Scenario 3). Simulations were performed with the WRF-CAMx model in Beijing, Tianjin, and Hebei Province in China (the BTH region) for January, April, July, and October of 2007, representing winter, spring, summer, and autumn, respectively. The results indicate that Scenario 1 can reduce the surface NOx concentrations by 20% in Beijing and Tianjin and by 5%in Hebei Province, and decrease the PM2.5 (particulate matter with diameters less than or equal to 2.5μm) concentrations by 10%in the BTH region. Scenarios 2 and 3 lead to decreases of more than 20%and more than 30%, respectively, in the surface concentrations of NOx and PM2.5 over the BTH region. This suggests that decreases in the surface concentrations of NOx and PM2.5 depend significantly on the amount of the catalyst used for SCR in diesel exhaust and natural gas boilers over the BTH region. The chemical process plays a key role in the formation of nitrates, sulfates, and ammonium salts, which are major components of PM2.5 over the BTH region. The surface concentrations of nitrates, sulfates, and ammonium salts contribute more than 60%in winter, spring, and autumn, more than 70% in summer and autumn, and approximately 25% in all four seasons, respectively, to the surface PM2.5 concentration. This implies that a large reduction in the emissions of major precursors of PM2.5, e.g., NOx, SO2, NH3, volatile organic compounds, and CO, can effectively reduce surface concentrations of PM2.5.%  针对京津冀地区主要大气污染物NOx(氮氧化物)和PM2.5(大气中粒径小于或等于2.5μm的颗粒物),应用柴油车尾气净

  11. Cycled storage-discharge plasma catalytic process for toluene removal from indoor air%循环的存储-放电等离子体催化新过程脱除室内空气中甲苯

    Institute of Scientific and Technical Information of China (English)

    范红玉; 李小松; 刘艳霞; 刘景林; 赵德志; 朱爱民

    2011-01-01

    Non-thermal plasmas (NTPs) technique has a great potential for indoor air purification, however, the high energy cost and secondary pollutants formation limit its practical application. To resolve these problems, a cycled storage-discharge (CSD) plasma catalytic process was explored for the removal of low-concentration toluene from indoor air in this study. The performance of toluene storage and plasma catalytic oxidation of adsorbed-state toluene over non-loaded and silver-loaded HZSM-5 catalysts was investigated. The experimental results showed that silver-loaded HZSM-5 catalysts gave a longer breakthrough time than non-loaded HZSM-5 catalysts at the storage stage (storage condition: 0. 1 g · m-3 C7H8, 40% relative humidity (RH, 25℃), 2000 ml · min-1 flow rate of simulated air). With input power of 40 W, the adsorbed-state toluene could be almost oxidized to CO2 in 10 min at the discharge stage (carbon balance about 100%, CO2 selectivity 98. 2%). It was further proved that there was no toluene desorbed during the process of plasma catalytic oxidation by on-line detection with mass spectrometry (MS) and Fourier transform infrared spectrometry (FTIR). Preliminary investigation on the stability of the CSD process for toluene removal was conducted. This study provides a novel plasma catalytic process for removing toluene from indoor air.%@@ 引言 室内空气中的挥发性有机化合物(VOCs),如甲醛(HCHO)、苯(CH)、甲苯(CH)等,是一类对人体有极大危害的室内空气污染物[1-2].传统的脱除VOCs的方法有吸附法、催化氧化法、热焚烧法等,这些方法在经济上或处理效率上或多或少存在缺陷.用于室内空气中VOCs脱除的理想方法应该同时具备脱除效率高、室温脱除、操作简单、能耗低及无二次污染物等特点.

  12. Three-Dimensional Composite Nanostructures for Lean NOx Emission Control

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Pu-Xian

    2013-07-31

    This final report to the Department of Energy (DOE) and National Energy Technology Laboratory (NETL) for DE-EE0000210 covers the period from October 1, 2009 to July 31, 2013. Under this project, DOE awarded UConn about $1,248,242 to conduct the research and development on a new class of 3D composite nanostructure based catalysts for lean NOx emission control. Much of the material presented here has already been submitted to DOE/NETL in quarterly technical reports. In this project, through a scalable solution process, we have successfully fabricated a new class of catalytic reactors, i.e., the composite nanostructure array (nano-array) based catalytic converters. These nanocatalysts, distinct from traditional powder washcoat based catalytic converters, directly integrate monolithic substrates together with nanostructures with well-defined size and shape during the scalable hydrothermal process. The new monolithic nanocatalysts are demonstrated to be able to save raw materials including Pt-group metals and support metal oxides by an order of magnitude, while perform well at various oxidation (e.g., CO oxidation and NO oxidation) and reduction reactions (H{sub 2} reduction of NOx) involved in the lean NOx emissions. The size, shape and arrangement of the composite nanostructures within the monolithic substrates are found to be the key in enabling the drastically reduced materials usage while maintaining the good catalytic reactivity in the enabled devices. The further understanding of the reaction kinetics associated with the unique mass transport and surface chemistry behind is needed for further optimizing the design and fabrication of good nanostructure array based catalytic converters. On the other hand, the high temperature stability, hydrothermal aging stability, as well as S-poisoning resistance have been investigated in this project on the nanocatalysts, which revealed promising results toward good chemical and mechanical robustness, as well as S

  13. Comparison of Aeration Strategies for Optimization of Nitrogen Removal in an Adsorption/Bio-oxidation (A/B) Process with an Emphasis on Ammonia vs. NOx (AvN) control

    OpenAIRE

    Sadowski, Michael Stuart

    2015-01-01

    Research was performed at a pilot-scale wastewater treatment plant operating an adsorption/bio-oxidation (A/B) process at 20C. The study compared B-Stage performance under DO Control, Ammonia Based Aeration Control (ABAC), and Ammonia vs. NOx (AvN) control. AvN in 1) fully-intermittent and 2) intermittently-aerated MLE configurations was compared to DO Control and ABAC, each with continuous aeration, in an MLE configuration. The study also examined operation of each aeration strategy with two...

  14. 40 CFR 60.4340 - How do I demonstrate continuous compliance for NOX if I do not use water or steam injection?

    Science.gov (United States)

    2010-07-01

    ... without add-on selective catalytic reduction (SCR) controls, you must define parameters indicative of the... determine whether the unit is operating in low-NOX mode. (iii) For any turbine that uses SCR to reduce...

  15. NOx reduction from compression ignition engines with pulsed corona discharge

    International Nuclear Information System (INIS)

    A study of pulsed corona discharge technology for NOx reduction from diesel engine exhaust is presented. The pulsed corona reactor consists of two coaxial cylinders used as electrodes of opposite polarities. The results are presented in terms of the cleanness (mass of NOx removed relative to its initial mass), and the efficiency (the energy required to theoretically dissociate 1 g of NOx, relative to the energy actually needed). Experimental results show that for a pulsed corona, the polarity of the electrodes has no significant effect on the reactor performance. Cleanness was found to be independent of the engine load. The pulsed corona reactor design considers the most efficient means of energy transfer from pulse-forming capacitor to the discharge zone. It is shown experimentally that an external electrode of smaller diameter provides better NOx reduction. For a pulsed corona reactor, the residence time that provides the best performance must be sufficient to allow all the pollutant molecules to interact with the radicals produced by the corona discharge. The residence time is calculated for the pulsed corona reactor and experimentally confirmed to be the one that results in the best cleanness and efficiency of NOx removal. The empirical relations, based on working conditions, are obtained and provide a route for reactor design

  16. Innovative technology for NOx direct decomposition

    OpenAIRE

    Tortorelli, Miriam

    2014-01-01

    Direct decomposition of NO to N2 and O2 would in principle constitute the most attractive solution to remove NOx since it does not require the use of a reducing agent. The main limitation to the application of this reaction is the slow kinetics. Indeed, the Cu-ZSM5, the only catalyst able to activate the NO decomposition providing reaction rates three orders of magnitude higher than the other catalysts at fairly low temperatures, shows lower performance compared to those reported for the trad...

  17. Pilot-Scale Removal of Trace Steroid Hormones and Pharmaceuticals and Personal Care Products from Municipal Wastewater Using a Heterogeneous Fenton’s Catalytic Process

    OpenAIRE

    George Tangyie Chi; John Churchley; Katherine D. Huddersman

    2013-01-01

    The pollution of water sources by endocrine disrupting compounds (EDCs) and pharmaceutical and personal care products (PPCPs) is a growing concern, as conventional municipal wastewater treatment systems are not capable of completely removing these contaminants. A continuous stir tank reactor incorporating a modified polyacrylonitrile (PAN) catalyst and dosed with hydrogen peroxide in a heterogeneous Fenton’s process was used at pilot scale to remove these compounds from wastewater that has un...

  18. Urea-SCR Temperature Investigation for NOx Control of Diesel Engine

    Directory of Open Access Journals (Sweden)

    Asif Muhammad

    2015-01-01

    Full Text Available SCR (selective catalytic reduction system is continuously being analyzed by many researchers worldwide on various concerns due to the stringent nitrogen oxides (NOx emissions legislation for heavy-duty diesel engines. Urea-SCR includes AdBlue as urea source, which subsequently decomposes to NH3 (ammonia being the reducing agent. Reaction temperature is a key factor for the performance of urea-SCR system, as urea decomposition rate is sensitive to a specific temperature range. This particular study was directed to investigate the temperature of the SCR system in diesel engine with the objective to confirm that whether the appropriate temperature is attained for occurrence of urea based catalytic reduction or otherwise and how the system performs on the prescribed temperature range. Diesel engine fitted with urea-SCR exhaust system has been operated on European standard cycle for emission testing to monitor the temperature and corresponding nitrogen oxides (NOx values on specified points. Moreover, mathematical expressions for approximation of reaction temperature are also proposed which are derived by applying energy conservation principal and gas laws. Results of the investigation have shown that during the whole testing cycle system temperature has remained in the range where urea-SCR can take place with best optimum rate and the system performance on account of NOx reduction was exemplary as excellent NOx conversion rate is achieved. It has also been confirmed that selective catalytic reduction (SCR is the best suitable technology for automotive engine-out NOx control.

  19. Vertical fluxes of NOx, HONO, and HNO3 above the snowpack at Summit, Greenland

    International Nuclear Information System (INIS)

    Vertical gradients of NOx, HONO, and HNO3 were measured in the lower 1-2 m above the snowpack at Summit, Greenland, during summer 2000. These measurements are used with simultaneous measurements of atmospheric turbulence using eddy covariance systems to determine the vertical fluxes of NOx, HONO, and HNO3. Upward fluxes of NOx and HONO were observed; these emissions were highly correlated with diurnally varying sunlight intensity, consistent with the expectation that they are the result of nitrate photolysis within the snowpack. The HNO3 flux was smaller in magnitude and more variable than those of HONO and NOx. It was usually downward, but emission was occasionally observed during mid-day. The 24-h average NOx emission (2.52x1012 molecules m-2 s-1) and HONO emission (4.64x1011 molecules m-2 s-1) rates were not balanced by the average HNO3 deposition rate (7.16x1011 molecules m-2 s-1), indicating that NOx export may slowly remove nitrogen from the system composed of the atmospheric boundary layer plus the top few cm of the surface snowpack, potentially affecting the amount of nitrate ultimately stored in glacial ice. These measurements imply that snowpack (NOx+HONO) emissions may alter NOx and (through HONO photolysis) OH levels in remote, snow-covered regions, but are small relative to other NOx sources on the global scale. (Author)

  20. Impact of NOx on secondary organic aerosol (SOA) formation from β-pinene photooxidation

    Science.gov (United States)

    Sarrafzadeh, Mehrnaz; Pullinen, Iida; Springer, Monika; Kleist, Einhard; Tillmann, Ralf; Mentel, Thomas F.; Kiendler-Scharr, Astrid; Hastie, Donald R.; Wildt, Jürgen

    2016-04-01

    Secondary organic aerosols (SOA) generated from atmospheric oxidation of volatile organics contributes substantially to the global aerosol load. It has been shown that odd nitrogen (NOx) has a significant influence on the formation of this SOA. In this study, we investigated SOA formation from β-pinene photooxidation in the Jülich Plant Atmosphere Chamber (JPAC) under varying NOx conditions. At higher-NOx levels, the SOA yield was significantly suppressed by increasing the NOx concentration. However at lower-NOx levels the opposite trend, an increase in SOA with increasing NOx concentration, was observed. This increase was likely due to the increased OH concentration in the stirred flow reactor. By holding the OH concentration constant for all experiments we removed the potential effect of OH concentration on SOA mass growth. In this case increasing the NOx concentration only decreased the SOA yield. In addition, the impact of NOx on SOA formation was explored in the presence of ammonium sulfate seed aerosols. This suggested that SOA yield was only slightly suppressed under increasing NOx concentrations when seed aerosol was present.

  1. NOx analyser interefence from alkenes

    Science.gov (United States)

    Bloss, W. J.; Alam, M. S.; Lee, J. D.; Vazquez, M.; Munoz, A.; Rodenas, M.

    2012-04-01

    Nitrogen oxides (NO and NO2, collectively NOx) are critical intermediates in atmospheric chemistry. NOx abundance controls the levels of the primary atmospheric oxidants OH, NO3 and O3, and regulates the ozone production which results from the degradation of volatile organic compounds. NOx are also atmospheric pollutants in their own right, and NO2 is commonly included in air quality objectives and regulations. In addition to their role in controlling ozone formation, NOx levels affect the production of other pollutants such as the lachrymator PAN, and the nitrate component of secondary aerosol particles. Consequently, accurate measurement of nitrogen oxides in the atmosphere is of major importance for understanding our atmosphere. The most widely employed approach for the measurement of NOx is chemiluminescent detection of NO2* from the NO + O3 reaction, combined with NO2 reduction by either a heated catalyst or photoconvertor. The reaction between alkenes and ozone is also chemiluminescent; therefore alkenes may contribute to the measured NOx signal, depending upon the instrumental background subtraction cycle employed. This interference has been noted previously, and indeed the effect has been used to measure both alkenes and ozone in the atmosphere. Here we report the results of a systematic investigation of the response of a selection of NOx analysers, ranging from systems used for routine air quality monitoring to atmospheric research instrumentation, to a series of alkenes ranging from ethene to the biogenic monoterpenes, as a function of conditions (co-reactants, humidity). Experiments were performed in the European Photoreactor (EUPHORE) to ensure common calibration, a common sample for the monitors, and to unequivocally confirm the alkene (via FTIR) and NO2 (via DOAS) levels present. The instrument responses ranged from negligible levels up to 10 % depending upon the alkene present and conditions used. Such interferences may be of substantial importance

  2. Impact of water quality on removal of carbamazepine in natural waters by N-doped TiO{sub 2} photo-catalytic thin film surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Avisar, Dror, E-mail: drorvi@post.tau.ac.il [The Hydro-Chemistry Laboratory, Faculty of Geography and the Environment, Tel Aviv University, Tel Aviv 69978 (Israel); Horovitz, Inna [The Hydro-Chemistry Laboratory, Faculty of Geography and the Environment, Tel Aviv University, Tel Aviv 69978 (Israel); School of Mechanical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv 69978 (Israel); Lozzi, Luca; Ruggieri, Fabrizio [Department of Physical and Chemical Sciences, University of L’Aquila, Via Vetoio, I-67010 Coppito, L’Aquila (Italy); Baker, Mark; Abel, Marie-Laure [The Surface Analysis Laboratory, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom); Mamane, Hadas [School of Mechanical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv 69978 (Israel)

    2013-01-15

    Highlights: ► N-doped TiO{sub 2} thin films have been deposited by sol–gel dip-coating. ► CBZ removal improved with increasing medium pH in the range of 5–9. ► DOC at a concentration of 5 mg/L resulted in an ∼20% reduction in CBZ removal. ► Alkalinity values of 100 mg/L as CaCO{sub 3} resulted in a 40% decrease in CBZ removal. ► Complete suppression of the photocatalytic process in wastewater effluent. -- Abstract: Photocatalytic experiments on the pharmaceutical pollutant carbamazepine (CBZ) were conducted using sol–gel nitrogen-doped TiO{sub 2}-coated glass slides under a solar simulator. CBZ was stable to photodegradation under direct solar irradiation. No CBZ sorption to the catalyst surface was observed, as further confirmed by surface characterization using X-ray photoelectron spectroscopic analysis of N-doped TiO{sub 2} surfaces. When exposing the catalyst surface to natural organic matter (NOM), an excess amount of carbon was detected relative to controls, which is consistent with NOM remaining on the catalyst surface. The catalyst surface charge was negative at pH values from 4 to 10 and decreased with increasing pH, correlated with enhanced CBZ removal with increasing medium pH in the range of 5–9. A dissolved organic carbon concentration of 5 mg/L resulted in ∼20% reduction in CBZ removal, probably due to competitive inhibition of the photocatalytic degradation of CBZ. At alkalinity values corresponding to CaCO{sub 3} addition at 100 mg/L, an over 40% decrease in CBZ removal was observed. A 35% reduction in CBZ occurred in the presence of surface water compared to complete suppression of the photocatalytic process in wastewater effluent.

  3. Nanomaterials to Combat NO(x) Pollution.

    Science.gov (United States)

    Balbuena, J; Cruz-Yusta, M; Sánchez, L

    2015-09-01

    The presence of NO9x) gases (NO+NO2) in the atmosphere is a major concern of society because of their associated adverse and harmful effects. In order to remove the NO(x) gases from the air, photocatalysis arises as an innovative and promising technique. Through the use of photochemical oxidation processes the NO and NO2 gases are oxidised to NO3- form and thus removed from the air. In recent years new nanomaterials are being developed by researchers with the aim to enhance their photocatalytic activity to combat the NO(x) pollution. The main focus is devoted to preparing new TiO2 based compounds with the highest specific surface area (SSA), different morphology and chemical modifications. In order to increase the SSA, different substrates were used to disperse the TiO2 nanoparticles: organic and carbon fibres, mesoporous materials, clays composites and nanoporous microparticles. In the other hand, high photocatalytic performances were obtained with nanotubes, self-orderer nano-tubular films and nanoparticles with the lowest size. Conversely, when TiO2 is doped with ions the oxide exhibited a better photocatalytic performance under visible light, which is related to the creation of intermediate energy states between the conduction band and the valence band. Alternatively, visible light photocatalysts different from titanium oxide have been studied, which exhibit a good De-NO(x) efficiency working under λ > 400 nm visible light irradiation.

  4. Sulfur Deactivation of NOx Storage Catalysts: A Multiscale Modeling Approach

    Directory of Open Access Journals (Sweden)

    Rankovic N.

    2013-09-01

    Full Text Available Lean NOx Trap (LNT catalysts, a promising solution for reducing the noxious nitrogen oxide emissions from the lean burn and Diesel engines, are technologically limited by the presence of sulfur in the exhaust gas stream. Sulfur stemming from both fuels and lubricating oils is oxidized during the combustion event and mainly exists as SOx (SO2 and SO3 in the exhaust. Sulfur oxides interact strongly with the NOx trapping material of a LNT to form thermodynamically favored sulfate species, consequently leading to the blockage of NOx sorption sites and altering the catalyst operation. Molecular and kinetic modeling represent a valuable tool for predicting system behavior and evaluating catalytic performances. The present paper demonstrates how fundamental ab initio calculations can be used as a valuable source for designing kinetic models developed in the IFP Exhaust library, intended for vehicle simulations. The concrete example we chose to illustrate our approach was SO3 adsorption on the model NOx storage material, BaO. SO3 adsorption was described for various sites (terraces, surface steps and kinks and bulk for a closer description of a real storage material. Additional rate and sensitivity analyses provided a deeper understanding of the poisoning phenomena.

  5. 40 CFR 97.12 - Changing NOX authorized account representative and alternate NOX authorized account...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Changing NOX authorized account representative and alternate NOX authorized account representative; changes in owners and operators. 97.12... (CONTINUED) FEDERAL NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS NOX Authorized...

  6. Pilot-Scale Removal of Trace Steroid Hormones and Pharmaceuticals and Personal Care Products from Municipal Wastewater Using a Heterogeneous Fenton’s Catalytic Process

    Directory of Open Access Journals (Sweden)

    George Tangyie Chi

    2013-01-01

    Full Text Available The pollution of water sources by endocrine disrupting compounds (EDCs and pharmaceutical and personal care products (PPCPs is a growing concern, as conventional municipal wastewater treatment systems are not capable of completely removing these contaminants. A continuous stir tank reactor incorporating a modified polyacrylonitrile (PAN catalyst and dosed with hydrogen peroxide in a heterogeneous Fenton’s process was used at pilot scale to remove these compounds from wastewater that has undergone previous treatment via a conventional wastewater treatment system. The treatment system was effective at ambient temperature and at the natural pH of the wastewater. High levels of both natural and synthetic hormones (EDCs and PPCPs were found in the effluent after biological treatment of the wastewater. The treatment system incorporating the modified PAN catalyst/H2O2 decomposed >90% of the EDCs and >40% of PPCPs using 200 mgL−1 H2O2, 3 hr residence time. The estrogenic potency EE2-EQ was removed by 82.77%, 91.36%, and 96.13% from three different wastewater treatment plants. BOD was completely removed (below detection limits; 30%–40% mineralisation was achieved and turbidity reduced by more than 68%. There was a <4% loss in iron content on the catalyst over the study period, suggesting negligible leaching of the catalyst.

  7. Retrofit SCR system for NOx control from heavy-duty mining equipment

    International Nuclear Information System (INIS)

    Diesel engines are used extensively in the mining industry and offer many advantages. However, particulate matter (PM) emissions and nitrogen oxide emissions (NOx) are among its disadvantages. A significant concern related to PM and NOx in an underground mine involves the use of diesel exhaust after treatment systems such as diesel particulate filters and selective catalytic reduction (SCR). This presentation discussed NOx and PM control and provided a description of an SCR system and examples of SCR retrofits. Options for NOx control were discussed and a case study involving the installation of an SCR retrofit system in an underground mine operated by Sifto Salt was also presented. The purpose of the case study was to identify cost effective retrofit solutions to lower nitrogen dioxide emissions from heavy-duty trucks operating in underground mines. The case study illustrated and presented the candidate vehicle, baseline emissions, a BlueMax SCR retrofit solution, and BlueMax installation. 1 tab., 6 figs.

  8. Nighttime NOx Chemistry in Coal-Fired Power Plant Plumes

    Science.gov (United States)

    Fibiger, D. L.; McDuffie, E. E.; Dube, W. P.; Veres, P. R.; Lopez-Hilfiker, F.; Lee, B. H.; Green, J. R.; Fiddler, M. N.; Ebben, C. J.; Sparks, T.; Weinheimer, A. J.; Montzka, D.; Campos, T. L.; Cohen, R. C.; Bililign, S.; Holloway, J. S.; Thornton, J. A.; Brown, S. S.

    2015-12-01

    Nitrogen oxides (NOx = NO + NO2) play a key role in atmospheric chemistry. During the day, they catalyze ozone (O3) production, while at night they can react to form nitric acid (HNO3) and nitryl chloride (ClNO2) and remove O3 from the atmosphere. These processes are well studied in the summer, but winter measurements are more limited. Coal-fired power plants are a major source of NOx to the atmosphere, making up approximately 30% of emissions in the US (epa.gov). NOx emissions can vary seasonally, as well as plant-to-plant, with important impacts on the details of the plume chemistry. In particular, due to inefficient plume dispersion, nighttime NOx emissions from power plants are held in concentrated plumes, where rates of mixing with ambient O3 have a strong influence on plume evolution. We will show results from the aircraft-based WINTER campaign over the northeastern United States, where several nighttime intercepts of power plant plumes were made. Several of these intercepts show complete O3 titration, which can have a large influence on NOx lifetime, and thus O3 production, in the plume. When power plant NO emissions exceed background O3 levels, O3 is completely consumed converting NO to NO2. In the presence of O3, NO2 will be oxidized to NO3, which will then react with NO2 to form N2O5, which can then form HNO3 and/or ClNO2 and, ultimately, remove NOx from the atmosphere or provide next-day oxidant sources. If there is no O3 present, however, no further chemistry can occur and NO and NO2 will be transported until mixing with sufficient O3 for higher oxidation products. Modeling results of plume development and mixing, which can tell us more about this transport, will also be presented.

  9. Entamoeba histolytica induces cell death of HT29 colonic epithelial cells via NOX1-derived ROS.

    Science.gov (United States)

    Kim, Kyeong Ah; Kim, Ju Young; Lee, Young Ah; Min, Arim; Bahk, Young Yil; Shin, Myeong Heon

    2013-02-01

    Entamoeba histolytica, which causes amoebic colitis and occasionally liver abscess in humans, is able to induce host cell death. However, signaling mechanisms of colon cell death induced by E. histolytica are not fully elucidated. In this study, we investigated the signaling role of NOX in cell death of HT29 colonic epithelial cells induced by E. histolytica. Incubation of HT29 cells with amoebic trophozoites resulted in DNA fragmentation that is a hallmark of apoptotic cell death. In addition, E. histolytica generate intracellular reactive oxygen species (ROS) in a contact-dependent manner. Inhibition of intracellular ROS level with treatment with DPI, an inhibitor of NADPH oxidases (NOXs), decreased Entamoeba-induced ROS generation and cell death in HT29 cells. However, pan-caspase inhibitor did not affect E. histolytica-induced HT29 cell death. In HT29 cells, catalytic subunit NOX1 and regulatory subunit Rac1 for NOX1 activation were highly expressed. We next investigated whether NADPH oxidase 1 (NOX1)-derived ROS is closely associated with HT29 cell death induced by E. histolytica. Suppression of Rac1 by siRNA significantly inhibited Entamoeba-induced cell death. Moreover, knockdown of NOX1 by siRNA, effectively inhibited E. histolytica-triggered DNA fragmentation in HT29 cells. These results suggest that NOX1-derived ROS is required for apoptotic cell death in HT29 colon epithelial cells induced by E. histolytica.

  10. Effect of K{sub 2}O on a Pd-containing catalytic converter for removing CO and HC emissions from a two-stroke motorcycle

    Energy Technology Data Exchange (ETDEWEB)

    Lee, C.H.; Chen, Y.W. [National Central Univ., Chung-Li (Taiwan, Province of China). Dept. of Chemical Engineering

    1998-04-01

    Noble metals (Pt, Pd, and Rh) supported on Al{sub 2}O{sub 3}, K{sub 2}/Al{sub 2}O{sub 3}, CeO{sub 2}/Al{sub 2}O{sub 3}, and K{sub 2}O/CeO{sub 2}/Al{sub 2}O{sub 3} were prepared and characterized with respect to surface area, pore volume, and temperature-programmed desorption of CO{sub 2}. The effects of K{sub 2}O on the noble-metal catalysts for carbon monoxide and hydrocarbon oxidation were investigated. The reactions were carried out under the stoichiometric and oxygen-deficient conditions. Under the stoichiometric point, the Pd-containing catalysts exhibit higher activity than the Pt-containing catalysts for both CO and C{sub 3}H{sub 6} oxidation. Moreover, Pd/K{sub 2}O/CeO{sub 2}/Al{sub 2}O{sub 3} is the most active catalyst among the powder catalysts in this study. Under the oxygen-deficient conditions and in the presence of water, the CO conversions on Pd/Al{sub 2}O{sub 3} and Pd/CeO{sub 2}/Al{sub 2}O{sub 3} are significantly lower than those on Pt/Al{sub 2}O{sub 3} and Pt/CeO{sub 2}/Al{sub 2}O{sub 3}, respectively. In contrast, the Pd-containing catalysts exhibit higher C{sub 3}H{sub 6} conversion than the Pt-containing catalysts. However, the CO conversions on the Pd-containing catalysts can be promoted by the addition of K{sub 2}O. On the other hand, the test results of the monolithic catalysts revealed that the CO conversion on PdRh/K{sub 2}O/Al{sub 2}O{sub 3}--CeO{sub 2} is quite close to that on PtRh/Al{sub 2}O{sub 3}-CeO{sub 2} under the simulative gases and the ECE-40 mode driving cycle test. PtRh/Al{sub 2}O{sub 3}-CeO{sub 2} is the typical composition of catalytic converters for two-stroke motorcycles. It infers that PdRh/K{sub 2}O/Al{sub 2}O{sub 3}-CeO{sub 2} is a promising catalytic converter for a two-stroke motorcycle.

  11. Gas Turbine Combustion and Ammonia Removal Technology of Gasified Fuels

    Directory of Open Access Journals (Sweden)

    Takeharu Hasegawa

    2010-03-01

    Full Text Available From the viewpoints of securing a stable supply of energy and protecting our global environment in the future, the integrated gasification combined cycle (IGCC power generation of various gasifying methods has been introduced in the world. Gasified fuels are chiefly characterized by the gasifying agents and the synthetic gas cleanup methods and can be divided into four types. The calorific value of the gasified fuel varies according to the gasifying agents and feedstocks of various resources, and ammonia originating from nitrogenous compounds in the feedstocks depends on the synthetic gas clean-up methods. In particular, air-blown gasified fuels provide low calorific fuel of 4 MJ/m3 and it is necessary to stabilize combustion. In contrast, the flame temperature of oxygen-blown gasified fuel of medium calorie between approximately 9–13 MJ/m3 is much higher, so control of thermal-NOx emissions is necessary. Moreover, to improve the thermal efficiency of IGCC, hot/dry type synthetic gas clean-up is needed. However, ammonia in the fuel is not removed and is supplied into the gas turbine where fuel-NOx is formed in the combustor. For these reasons, suitable combustion technology for each gasified fuel is important. This paper outlines combustion technologies and combustor designs of the high temperature gas turbine for various IGCCs. Additionally, this paper confirms that further decreases in fuel-NOx emissions can be achieved by removing ammonia from gasified fuels through the application of selective, non-catalytic denitration. From these basic considerations, the performance of specifically designed combustors for each IGCC proved the proposed methods to be sufficiently effective. The combustors were able to achieve strong results, decreasing thermal-NOx emissions to 10 ppm (corrected at 16% oxygen or less, and fuel-NOx emissions by 60% or more, under conditions where ammonia concentration per fuel heating value in unit volume was 2.4 × 102 ppm

  12. Hydrogen Effect on Coke Removal and Catalytic Performance in Pre-Carburization and Methane Dehydro-Aromatization Reaction on Mo/HZSM-5

    Institute of Scientific and Technical Information of China (English)

    Hongtao Ma; Ryoichi Kojima; Satoshi Kikuchi; Masaru Ichikawa

    2005-01-01

    In this study,the effects of pre-carburization of catalyst,hydrogen addition to methane feed and the space velocity of methane on the catalytic performance in methane to benzene (MTB) reaction were discussed in detail over Mo/HZSM-5 catalyst at 1023 K and 0.3 MPa. Compared with the non-precarburized catalyst,the Mo catalyst pre-carburized under the flow of CH4+4H2 at 973 K was found to have the higher activity and better stability. Further 6% H2 addition to the methane feed suppressed the aromatic type of coke formation effectively,and improved the stability of catalyst markedly,moreover gave a much longer reaction life of catalyst (53 h at 1023 K and 5400 ml/(g·h)) and much more formation amounts of benzene and hydrogen. With increase of methane space velocity,both the naphthalene formation selectivity and the coke formation selectivity were decreased by the shortened contact time;the benzene formation selectivity and total formation amount before the complete deactivation of catalyst were increased ly,while the total naphthalene and coke formation amounts did not change much.At high methane space velocity (≥5400 ml/(g·h)),a new middle temperature coke derived from the high temperature aromatic coke was formed on the catalyst; all the coke formed could be burnt off at lower temperature in oxygen,compared with those obtained at low space velocity. Considering the benzene formation amount and catalyst stability together,5400 ml/(g·h) was proved to be the most efficient methane space velocity for benzene production.

  13. Plasma-assisted combustion technology for NOx reduction in industrial burners.

    Science.gov (United States)

    Lee, Dae Hoon; Kim, Kwan-Tae; Kang, Hee Seok; Song, Young-Hoon; Park, Jae Eon

    2013-10-01

    Stronger regulations on nitrogen oxide (NOx) production have recently promoted the creation of a diverse array of technologies for NOx reduction, particularly within the combustion process, where reduction is least expensive. In this paper, we discuss a new combustion technology that can reduce NOx emissions within industrial burners to single-digit parts per million levels without employing exhaust gas recirculation or other NOx reduction mechanisms. This new technology uses a simple modification of commercial burners, such that they are able to perform plasma-assisted staged combustion without altering the outer configuration of the commercial reference burner. We embedded the first-stage combustor within the head of the commercial reference burner, where it operated as a reformer that could host a partial oxidation process, producing hydrogen-rich reformate or synthesis gas product. The resulting hydrogen-rich flow then ignited and stabilized the combustion flame apart from the burner rim. Ultimately, the enhanced mixing and removal of hot spots with a widened flame area acted as the main mechanisms of NOx reduction. Because this plasma burner acted as a low NOx burner and was able to reduce NOx by more than half compared to the commercial reference burner, this methodology offers important cost-effective possibilities for NOx reduction in industrial applications. PMID:24032692

  14. Plasma-assisted combustion technology for NOx reduction in industrial burners.

    Science.gov (United States)

    Lee, Dae Hoon; Kim, Kwan-Tae; Kang, Hee Seok; Song, Young-Hoon; Park, Jae Eon

    2013-10-01

    Stronger regulations on nitrogen oxide (NOx) production have recently promoted the creation of a diverse array of technologies for NOx reduction, particularly within the combustion process, where reduction is least expensive. In this paper, we discuss a new combustion technology that can reduce NOx emissions within industrial burners to single-digit parts per million levels without employing exhaust gas recirculation or other NOx reduction mechanisms. This new technology uses a simple modification of commercial burners, such that they are able to perform plasma-assisted staged combustion without altering the outer configuration of the commercial reference burner. We embedded the first-stage combustor within the head of the commercial reference burner, where it operated as a reformer that could host a partial oxidation process, producing hydrogen-rich reformate or synthesis gas product. The resulting hydrogen-rich flow then ignited and stabilized the combustion flame apart from the burner rim. Ultimately, the enhanced mixing and removal of hot spots with a widened flame area acted as the main mechanisms of NOx reduction. Because this plasma burner acted as a low NOx burner and was able to reduce NOx by more than half compared to the commercial reference burner, this methodology offers important cost-effective possibilities for NOx reduction in industrial applications.

  15. Performance of an activated carbon made from waste palm shell in simultaneous adsorption of SO_x and NO_x of flue gas at low temperature

    Institute of Scientific and Technical Information of China (English)

    S.; SUMATHI; S.; BHATIA; K.T.; LEE; A.; R.; MOHAMED

    2009-01-01

    This study examined the individual and simultaneous adsorption of SOx (SO2) and NOx (NO-NO2) on activated carbon prepared from waste palm shell. The adsorption process was examined in a fixed bed reactor at low temperatures (100―300℃). For individual adsorption without any catalytic activation, SOx showed good adsorption whereas NOx was very much poor. In the simultaneous adsorption of SOx and NOx, SOx showed greater adsorption affinity than NOx. For palm shell activated carbon (PSAC) impregnated with metal catalyst (Ni and Ce) the concentration adsorbed profile showed that the amount of SOx adsorbed decreased regularly, while the amount of the adsorbed NOx increased irregularly. The properties of the pure and impregnated PSAC were analyzed by BET, SEM and EDX. These investiga-tions indicated that PSAC impregnated with metal catalyst is the determining factor in the adsorption of SOx and NOx simultaneously.

  16. Performance of an activated carbon made from waste palm shell in simultaneous adsorption of SOx and NOx of flue gas at low temperature

    Institute of Scientific and Technical Information of China (English)

    S.SUMATHI; S.BHATIA; K.T.LEE; A.R.MOHAMED

    2009-01-01

    This study examined the individual and simultaneous adsorption of SOx (SO2) and NOx (NO-NO2) on activated carbon prepared from waste palm shell. The adsorption process was examined in a fixed bed reactor at low temperatures (100-300℃). For individual adsorption without any catalytic activation, SOx showed good adsorption whereas NOx was very much poor. In the simultaneous adsorption of SOx and NOx, SOx showed greater adsorption affinity than NOx. For palm shell activated carbon (PSAC) im-pregnated with metal catalyst (Ni and Ce) the concentration adsorbed profile showed that the amount of SOx adsorbed decreased regularly, while the amount of the adsorbed NOx increased irregularly. The properties of the pure and impregnated PSAC were analyzed by BET, SEM and EDX. These investiga-tions indicated that PSAC impregnated with metal catalyst is the determining factor in the adsorption of SOxand NOx simultaneously.

  17. Fundamental limitations of non-thermal plasma processing for internal combustion engine NOx control

    International Nuclear Information System (INIS)

    This paper discusses the physics and chemistry of non-thermal plasma processing for post-combustion NOx control in internal combustion engines. A comparison of electron beam and electrical discharge processing is made regarding their power consumption, radical production, NOx removal mechanisms, and by product formation. Can non-thermal deNOx operate efficiently without additives or catalysts? How much electrical power does it cost to operate? What are the by-products of the process? This paper addresses these fundamental issues based on an analysis of the electron-molecule processes and chemical kinetics

  18. Determination of adsorptive and catalytic properties of copper, silver and iron contain titanium-pillared bentonite for the removal bisphenol A from aqueous solution

    Science.gov (United States)

    Tomul, Fatma; Turgut Basoglu, Funda; Canbay, Hale

    2016-01-01

    Ti-pillared bentonite, Cu, Ag and Fe modified Ti-pillared bentonite and Cu/Ti- and Fe/Ti-mixed pillared bentonite were synthesized using different titanium sources by direct synthesis or by modification after synthesis. The effects of synthesis conditions on the surface characteristics, pore structure and acidity of the pillared bentonites were investigated by SEM-EDS, XPS, XRD, N2-adsorption/desorption and FTIR analyses before and after ammonia adsorption. The results of EDS, XPS and XRD analysis confirmed that titanium, copper, silver and iron were incorporated into the bentonite structure. In the XRD patterns, the formation of delaminated structure reflecting the non-parallel distribution of the bentonite layers by pillaring with Ti, Cu/Ti and Fe/Ti-pillars was observed. XPS spectra indicated the presence of TiO2, CuO, Ag and Ag2O and Fe2O3 species depending on the source of active metals in the synthesized samples. In the FTIR spectra, an increase in the Bronsted/Lewis peak intensity was observed with the loading of copper and iron, whereas a decrease in Lewis and Bronsted acidities was observed with incorporation of silver. Adsorption studies indicated that the adsorption capacity of the sample synthesized using titanium (IV) propoxide and incorporating iron to the structure by ion exchange (Fe-PTi-PILC) were higher than those in other samples. The adsorption of BPA (bisphenol A) by all tested samples was found to fit the Langmuir isotherm. In the catalytic wet peroxide oxidation (CWPO) over PTi-PILC (prepared by titanium (IV) propoxide), Fe-PTi-PILC and Cu-PTi-PILC (prepared by copper impregnated Ti-pillared bentonite) samples, BPA values close to complete conversion were achieved within 30 min at 25 °C, pH 4 and 5 g/L mcat. CWPO results showed that increasement of pH causes a decrease the rate of oxidation. On the other hand, by the time catalyst and BPA concentration is increased, the rate of oxidation is increased as well.

  19. 高级催化氧化法去除水中邻苯二甲酸酯的研究进展%Removal of phthalic acid esters from water by advanced catalytic oxidation process

    Institute of Scientific and Technical Information of China (English)

    刘静; 李亚茹; 王杰; 陈凯凯

    2014-01-01

    Generally, phthalic acid esters(PAEs) are considered to be endocrine disrupting chemicals (EDCs). This substance is widely used in plasticizers, cosmetics, etc. PAEs would give rise to malformation, cancerization and mutation as well as possess quasi/anti-estrogen activity and quasi/resistance-thyroid hormone activity. PAEs could spread to the environment easily and be detected in the soil, air and water. They are common pollutants in the environment, which pose serious threats to both human health and the ecological environment. As a result, PAEs have attracted widespread attention at home and abroad. This paper summarizes the physi-chemical properties and toxic effects of PAEs and analyses the pollution status in natural water, groundwater and wastewater. The work also discusses many recent methods developed to remove PAEs, such as enhanced coagulation, adsorption, membrane treatment, biological treatment, advanced oxidation process, etc. Advanced oxidation technology has attracted much attention and developed rapidly because of it’s ability to remove different kinds of organic pollutants quickly and efficiently from drinking water and sewage. This article introduces the degradation of PAEs in water mainly using advanced oxidation technology which includes the catalytic wet peroxide oxidation, the catalytic ozone oxidation, photocatalytic oxidation, ultrasonic and microwave assisted catalytic oxidation and advanced nanometer catalytic oxidation. Fenton catalytic oxidation process could produce highly reactive hydroxyl radicals by adding catalyst and UVradiation in the process of oxidation. This method could achieve the highest oxidation efficiency as well as degrade PAEs into non-toxic harmless chemicals completely and non-selectively. Although application of the catalyst in advanced oxidation process can improve the oxidation efficiency and the degradation degree greatly, this method needs a huge amount of catalyst and energy and also influenced by pH value

  20. Discovery of Novel NOx Catalysts for CIDI Applications by High-throughput Methods

    Energy Technology Data Exchange (ETDEWEB)

    Blint, Richard J. [General Motors Corporation, Warren, MI (United States)

    2007-12-31

    DOE project DE-PS26-00NT40758 has developed very active, lean exhaust, NOx reduction catalysts that have been tested on the discovery system, laboratory reactors and engine dynamometer systems. The goal of this project is the development of effective, affordable NOx reduction catalysts for lean combustion engines in the US light duty vehicle market which can meet Tier II emission standards with hydrocarbons based reductants for reducing NOx. General Motors (prime contractor) along with subcontractors BASF (Engelhard) (a catalytic converter developer) and ACCELRYS (an informatics supplier) carried out this project which began in August of 2002. BASF (Engelhard) has run over 16,000 tests of 6100 possible catalytic materials on a high throughput discovery system suitable for automotive catalytic materials. Accelrys developed a new database informatics system which allowed material tracking and data mining. A program catalyst was identified and evaluated at all levels of the program. Dynamometer evaluations of the program catalyst both with and without additives show 92% NOx conversions on the HWFET, 76% on the US06, 60% on the cold FTP and 65% on the Set 13 heavy duty test using diesel fuel. Conversions of over 92% on the heavy duty FTP using ethanol as a second fluid reductant have been measured. These can be competitive with both of the alternative lean NOx reduction technologies presently in the market. Conversions of about 80% were measured on the EUDC for lean gasoline applications without using active dosing to adjust the C:N ratio for optimum NOx reduction at all points in the certification cycle. A feasibility analysis has been completed and demonstrates the advantages and disadvantages of the technology using these materials compared with other potential technologies. The teaming agreements among the partners contain no obstacles to commercialization of new technologies to any potential catalyst customers.

  1. Catalytic distillation water recovery subsystem

    Science.gov (United States)

    Budininkas, P.; Rasouli, F.

    1985-01-01

    An integrated engineering breadboard subsystem for the recovery of potable water from untreated urine based on the vapor phase catalytic ammonia removal was designed, fabricated and tested. Unlike other evaporative methods, this process catalytically oxidizes ammonia and volatile hydrocarbons vaporizing with water to innocuous products; therefore, no pretreatment of urine is required. Since the subsystem is fabricated from commercially available components, its volume, weight and power requirements are not optimized; however, it is suitable for zero-g operation. The testing program consists of parametric tests, one month of daily tests and a continuous test of 168 hours duration. The recovered water is clear, odorless, low in ammonia and organic carbon, and requires only an adjustment of its pH to meet potable water standards. The obtained data indicate that the vapor phase catalytic ammonia removal process, if further developed, would also be competitive with other water recovery systems in weight, volume and power requirements.

  2. The DeNOx process and NO2 adsorption in MOF74

    Science.gov (United States)

    Zuluaga, S.; Thonhauser, T.; Tan, K.; Chabal, Y.

    2014-03-01

    Due to the harmful character of NO2 and its slow decomposition rate, the use of catalytic materials for its removal (DeNOx process) has attracted a lot of attention. The high porosity and highly reactive uncoordinated metal centers of MOF74 have led us to investigate the use of Mg- and Zn-MOF74 as materials for trapping NO2 with resistance to poisoning by SO2. In this combined theoretical and experimental study, we investigate the interaction between the unsaturated metal centers of the MOF and the NO2 guest molecules. For our theoretical modeling we use ab initio calculations at the DFT level, utilizing vdW-DF to capture the significant van der Waals component of the interaction between NO2 and the MOF. We present detailed first-principle results concerning the adsorption energies and geometries, as well as vibration frequencies of the NO2 molecule adsorbed in the MOF. Our experimental efforts (IR and Raman spectroscopy) have shown a blue shift to 1684 cm-1 in the vibration stretching mode of the NO2 upon adsorption and a thermal stability up to 150°C. Our first-principle calculations and experimental results show a remarkable agreement, allowing us to give a complete picture of the adsorption of NO2 molecules in the MOF74 structure. Supported by DOE DE-FG02-08ER46491.

  3. Modeling the Formation of N2O and NO2 in the Thermal De-NOx Process

    DEFF Research Database (Denmark)

    Miller, James A.; Glarborg, Peter

    1996-01-01

    A chemical kinetic model is formulated that satisfactorily predicts the NO removed and the N2O and NO2 produced by the Thermal De-NOx process over a wide range of temperatures and initial oxygen concentrations.......A chemical kinetic model is formulated that satisfactorily predicts the NO removed and the N2O and NO2 produced by the Thermal De-NOx process over a wide range of temperatures and initial oxygen concentrations....

  4. 40 CFR 96.188 - CAIR NOX allowance allocations to CAIR NOX opt-in units.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false CAIR NOX allowance allocations to CAIR NOX opt-in units. 96.188 Section 96.188 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS...

  5. 40 CFR 97.188 - CAIR NOX allowance allocations to CAIR NOX opt-in units.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false CAIR NOX allowance allocations to CAIR NOX opt-in units. 97.188 Section 97.188 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) FEDERAL NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING...

  6. 40 CFR 96.52 - NOX Allowance Tracking System responsibilities of NOX authorized account representative.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false NOX Allowance Tracking System responsibilities of NOX authorized account representative. 96.52 Section 96.52 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX...

  7. 40 CFR 97.11 - Alternate NOX authorized account representative.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Alternate NOX authorized account... PROGRAMS (CONTINUED) FEDERAL NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS NOX Authorized Account Representative for NOX Budget Sources § 97.11 Alternate NOX authorized...

  8. Nox Inhibitors & Therapies: Rational Design of Peptidic and Small Molecule Inhibitors

    Science.gov (United States)

    Cifuentes-Pagano, M. Eugenia; Meijles, Daniel N.; Pagano, Patrick J.

    2016-01-01

    Oxidative stress-related diseases underlie many if not all of the major leading causes of death in United States and the Western World. Thus, enormous interest from both academia and pharmaceutical industry has been placed on the development of agents which attenuate oxidative stress. With that in mind, great efforts have been placed in the development of inhibitors of NADPH oxidase (Nox), the major enzymatic source of reactive oxygen species and oxidative stress in many cells and tissue. The regulation of a catalytically active Nox enzyme involves numerous protein-protein interactions which, in turn, afford numerous targets for inhibition of its activity. In this review, we will provide an updated overview of the available Nox inhibitors, both peptidic and small molecules, and discuss the body of data related to their possible mechanisms of action and specificity towards each of the various isoforms of Nox. Indeed, there have been some very notable successes. However, despite great commitment by many in the field, the need for efficacious and well-characterized, isoform-specific Nox inhibitors, essential for the treatment of major diseases as well as for delineating the contribution of a given Nox in physiological redox signalling, continues to grow. PMID:26510437

  9. Real world NOx emissions of Euro V vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Verbeek, R.; Vonk, W.A.; Verbeek, R.P.; Dekker, H. [TNO Science and Industry, Delft (Netherlands)

    2010-11-15

    In the past decade, vehicle emissions have been reduced substantially as a result of the European emission legislation. Air quality problems are still present, however, in particular in urban areas where local authorities have difficulty meeting European limits regarding air quality (mainly NO2). Therefore, the emission performance of vehicles under urban conditions is of increasing importance for air quality improvement in cities. In this context, TNO was commissioned by the Dutch Ministry of Environment (VROM) to investigate the real-world NOx emissions of Euro V trucks and buses during the past two years. The investigation has shown that, in general, there is a large variety in real-world emissions between different vehicles, in particular under urban conditions. Some vehicles demonstrate the possibility of achieving low emissions under urban conditions, but the results also clearly show that this is not the case for most of the trucks. This outcome is based on two lines of research. Firstly, the real world emissions of eleven trucks and one bus were measured on-road using a Portable Emission Measurement System (PEMS), under conditions typical of everyday use. Secondly, AdBlue consumption data for a number of Dutch vehicle fleets were analysed. AdBlue is the reagent that is used for NOx emission reduction in SCR systems (catalytic after treatment systems), and the amount of reagent used in daily practice is related to the real-world NOx emissions. Both lines of research support the general outcome.

  10. Multiphase catalysts for selective reduction of NOx with hydrocarbons

    International Nuclear Information System (INIS)

    Among the existing proposed solutions to reduce emission of NOx there is a promising alternative, the so-called (HC-SCR) selective catalytic reduction of NOx using hydrocarbons as reductant. This thesis is part of a worldwide effort devoted to gain knowledge on the selective catalytic reduction of NOx with hydrocarbons with the final goal to contribute to the development of suitable catalysts for the above mentioned process. Chapter 2 describes the details of the experimental set-up and of the analytical methods employed. Among the catalyst for HC-SCR, Co-based catalyst are known to be active and selective, thus, a study on a series of Co-based catalysts, supported on zeolites, was undertaken and the results are presented in Chapter 3. Correlation between catalytic characteristics and kinetic results are employed to understand the working catalyst and this is used as a basis for catalyst optimization. With the intention to prepare a multi-functional catalyst that will preserve the desired characteristics of the individual components, minimizing their negative aspects, catalysts based on Co-Pt, supported on ZSM-5, were investigated. In Chapter 4 the results of this study are discussed. A bimetallic Co-Pt/ZSM-5 catalysts with low Pt contents (0.1 wt %) showed a synergistic effect by combining high stability and activity of Pt catalysts with the high N2 selectivity of Co catalysts. Furthermore, it was found to be sulfur- and water-tolerant. Its positive qualities brought us to study the mechanism that takes place over this catalyst during HC-SCR. The results of an in-situ i.r mechanistic study over this catalyst is reported in Chapter 5. From the results presented in Chapter 5 a mechanism operating over the Co-Pt/ZSM-5 catalyst is proposed. The modification of Co catalyst with Pt improved the catalysts. However, further improvement was found to be hindered by high selectivity to N2O. Since Rh catalysts are generally less selective to N2O, the modification of Co

  11. Mass transfer in the absorption of SO2 and NOx using aqueous euchlorine scrubbing solution

    Institute of Scientific and Technical Information of China (English)

    DESHWAL Bal-Raj; LEE Hyung-Keun

    2009-01-01

    Attempts have been made to generate euchlorine gas by chlorate-chloride process and to utilize it further to clean up SO2 and NOx from the flue gas in a lab scale bubbling reactor.Preliminary experiments were carried out to determine the gas and liquid phase mass transfer coefficients and their correlation equations have been established.Simultaneous removal of SO2 and NOx from the simulated flue gas using aqueous euchlorine scrubbing solution has been investigated.Euchlorine oxidized NO into NO2 completely and the later subsequently absorbed into the scrubbing solution in the form of nitrate.SO2 removal efficiency of around 100% and NOx removal efficiency of around 72 % were achieved under optimized conditions.Mass balance has been confirmed by analyzing the sulfate, nitrate, euchlorine and chloride ion using ion chromatograph/auto-titrator and comparing it with their corresponding calculated values.

  12. 静电分离催化裂化油浆中固体颗粒及其组成的研究%Removing Solid Particles in Fluid Catalytic Cracking Slurry by Electrostatic Separation and Their Composition

    Institute of Scientific and Technical Information of China (English)

    赵娜; 于传瑞; 赵波; 陈坤; 郭爱军; 王宗贤

    2015-01-01

    采用自制的静电分离装置,对某重油催化裂化装置外甩的催化裂化油浆(FCCS)进行静电分离实验。考察分离时间、温度、填料粒径、电场强度及分离级数对静电脱除效率的影响,并采用SEM,EDS,XRD等方法对固体颗粒进行表征。实验结果表明,静电脱除效率,随静电分离时间的延长先增大后趋于稳定,随温度的升高而增大,随填料粒径的减小而增大,随电场强度的增加先增大后有所降低;适宜的分离条件为:分离时间25~30 min、温度140~160℃、填料粒径2.0~2.5 mm、电场强度3.5 kV/cm,在此条件下经三级静电分离可使静电脱除效率最高达到99%,FCCS中的固体颗粒含量由4200 mg/L降至50 mg/L以下;FCCS中的固体颗粒主要由催化剂细粉、焦粉和金属锑组成。%The electrostatic separation of fluid catalytic cracking slurry(FCCS) from a heavy oil catalytic cracking unit was carried out in a self-made experimental installation. The influences of processing time,temperature,packing diameter,separation stages and electric field intensity on the electrostatic removal efficiency were investigated. The solid particles in FCCS were characterized by means of SEM,EDS and XRD. The experimental results showed that,the electrostatic removal efficiency firstly increased and then stabilized with prolonging the processing time,increased with the temperature rise,increased with the decrease of the packing diameter,and increased and then decreased with the increase of the electric field intensity. Under the appropriate conditions of processing time 25-30 min,temperature 140-160℃,packing diameter 2.0-2.5 mm and electric field intensity 3.5 kV/cm,through three-stage of electrostatic separation,the electrostatic removal efficiency reached 99% and the content of the solid particles in FCCS lowered from 4 200 mg/L to less than 50 mg/L. The solid particles in FCCS consisted of catalyst powder

  13. Novel Catalytic Membrane Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Stuart Nemser, PhD

    2010-10-01

    There are many industrial catalytic organic reversible reactions with amines or alcohols that have water as one of the products. Many of these reactions are homogeneously catalyzed. In all cases removal of water facilitates the reaction and produces more of the desired chemical product. By shifting the reaction to right we produce more chemical product with little or no additional capital investment. Many of these reactions can also relate to bioprocesses. Given the large number of water-organic compound separations achievable and the ability of the Compact Membrane Systems, Inc. (CMS) perfluoro membranes to withstand these harsh operating conditions, this is an ideal demonstration system for the water-of-reaction removal using a membrane reactor. Enhanced reaction synthesis is consistent with the DOE objective to lower the energy intensity of U.S. industry 25% by 2017 in accord with the Energy Policy Act of 2005 and to improve the United States manufacturing competitiveness. The objective of this program is to develop the platform technology for enhancing homogeneous catalytic chemical syntheses.

  14. NOx Change over China and Its Influences

    Institute of Scientific and Technical Information of China (English)

    LIU Yu(刘煜); I. S. A. ISAKSEN; J. K. SUNDET; HE Jinhai(何金海); YAN Peng(颜鹏)

    2004-01-01

    A 3-D chemical transport model (OSLO CTM2) is used to investigate the impact of the increase of NOx emission over China.The model is capable to reproduce basically the seasonal variation of surface NOx and ozone over eastern China.NOx emission data and observations reveal that NOx over easternChina increases quite quickly with the economic development of China.Model results indicate that NOxconcentration over eastern China increasingly rises with the increase of NOx emission over China,and accelerates to increase in winter.When the NOx emission increases from 1995 to its double,the ratio of NO2/NOx abruptly drops in winter over northern China.Ozone at the surface decreases in winter with the continual enhancement of the NOx level over eastern China,but increases over southern China in summertime.It is noticeable that peak ozone over northern China increases in summer although mean ozone changes little.In summer,ozone increases in the free troposphere dominantly below 500 hPa.Moreover,the increases of total ozone over eastern China are proportional to the increases of NOx emission.In a word,the model results suggest that the relationship between NOx and ozone at the surface would change with NOx increase.

  15. Advanced In-Furnace NOx Control for Wall and Cyclone-Fired Boilers

    International Nuclear Information System (INIS)

    A NOx minimization strategy for coal-burning wall-fired and cyclone boilers was developed that included deep air staging, innovative oxygen use, reburning, and advanced combustion control enhancements. Computational fluid dynamics modeling was applied to refine and select the best arrangements. Pilot-scale tests were conducted by firing an eastern high-volatile bituminous Pittsburgh No.8 coal at 5 million Btu/hr in a facility that was set up with two-level overfire air (OFA) ports. In the wall-fired mode, pulverized coal was burned in a geometrically scaled down version of the B and W DRB-4Z(reg sign) low-NOx burner. At a fixed overall excess air level of 17%, NOx emissions with single-level OFA ports were around 0.32 lb/million Btu at 0.80 burner stoichiometry. Two-level OFA operation lowered the NOx levels to 0.25 lb/million Btu. Oxygen enrichment in the staged burner reduced the NOx values to 0.21 lb/million Btu. Oxygen enrichment plus reburning and 2-level OFA operation further curbed the NOx emissions to 0.19 lb/million Btu or by 41% from conventional air-staged operation with single-level OFA ports. In the cyclone firing arrangement, oxygen enrichment of the cyclone combustor enabled high-temperature and deeply staged operation while maintaining good slag tapping. Firing the Pittsburgh No.8 coal in the optimum arrangement generated 112 ppmv NOx (0.15 lb/million Btu) and 59 ppmv CO. The optimum emissions results represent 88% NOx reduction from the uncontrolled operation. Levelized costs for additional NOx removal by various in-furnace control methods in reference wall-fired or cyclone-fired units already equipped with single-level OFA ports were estimated and compared with figures for SCR systems achieving 0.1 lb NOx/106 Btu. Two-level OFA ports could offer the most economical approach for moderate NOx control, especially for smaller units. O2 enrichment in combination with 2-level OFA was not cost effective for wall-firing. For cyclone units, NOx removal by

  16. Pilot‐scale investigation and CFD modeling of particle deposition in low‐dust monolithic SCR DeNOx catalysts

    DEFF Research Database (Denmark)

    Heiredal, Michael Lykke; Jensen, Anker Degn; Thøgersen, Joakim Reimer;

    2013-01-01

    Deposition of particles in selective catalytic reduction DeNOx monolithic catalysts was studied by low‐dust pilot‐scale experiments. The experiments showed a total deposition efficiency of about 30%, and the deposition pattern was similar to that observed in full‐scale low‐dust applications. On e...

  17. Low NOx heavy fuel combustor concept program. Phase 1: Combustion technology generation

    Science.gov (United States)

    Lew, H. G.; Carl, D. R.; Vermes, G.; Dezubay, E. A.; Schwab, J. A.; Prothroe, D.

    1981-01-01

    The viability of low emission nitrogen oxide (NOx) gas turbine combustors for industrial and utility application. Thirteen different concepts were evolved and most were tested. Acceptable performance was demonstrated for four of the combustors using ERBS fuel and ultralow NOx emissions were obtained for lean catalytic combustion. Residual oil and coal derived liquids containing fuel bound nitrogen (FBN) were also used at test fuels, and it was shown that staged rich/lean combustion was effective in minimizing the conversion of FBN to NOx. The rich/lean concept was tested with both modular and integral combustors. While the ceramic lined modular configuration produced the best results, the advantages of the all metal integral burners make them candidates for future development. An example of scaling the laboratory sized combustor to a 100 MW size engine is included in the report as are recommendations for future work.

  18. Industrial Gas Turbine Engine Catalytic Pilot Combustor-Prototype Testing

    Energy Technology Data Exchange (ETDEWEB)

    Etemad, Shahrokh [Precision Combustion, Inc., North Haven, CT (United States); Baird, Benjamin [Precision Combustion, Inc., North Haven, CT (United States); Alavandi, Sandeep [Precision Combustion, Inc., North Haven, CT (United States); Pfefferle, William [Precision Combustion, Inc., North Haven, CT (United States)

    2010-04-01

    PCI has developed and demonstrated its Rich Catalytic Lean-burn (RCL®) technology for industrial and utility gas turbines to meet DOE's goals of low single digit emissions. The technology offers stable combustion with extended turndown allowing ultra-low emissions without the cost of exhaust after-treatment and further increasing overall efficiency (avoidance of after-treatment losses). The objective of the work was to develop and demonstrate emission benefits of the catalytic technology to meet strict emissions regulations. Two different applications of the RCL® concept were demonstrated: RCL® catalytic pilot and Full RCL®. The RCL® catalytic pilot was designed to replace the existing pilot (a typical source of high NOx production) in the existing Dry Low NOx (DLN) injector, providing benefit of catalytic combustion while minimizing engine modification. This report discusses the development and single injector and engine testing of a set of T70 injectors equipped with RCL® pilots for natural gas applications. The overall (catalytic pilot plus main injector) program NOx target of less than 5 ppm (corrected to 15% oxygen) was achieved in the T70 engine for the complete set of conditions with engine CO emissions less than 10 ppm. Combustor acoustics were low (at or below 0.1 psi RMS) during testing. The RCL® catalytic pilot supported engine startup and shutdown process without major modification of existing engine controls. During high pressure testing, the catalytic pilot showed no incidence of flashback or autoignition while operating over a wide range of flame temperatures. In applications where lower NOx production is required (i.e. less than 3 ppm), in parallel, a Full RCL® combustor was developed that replaces the existing DLN injector providing potential for maximum emissions reduction. This concept was tested at industrial gas turbine conditions in a Solar Turbines, Incorporated high-pressure (17 atm.) combustion rig and in a modified Solar

  19. Development of adsorption process for NOx recycling in a reprocessing plant

    International Nuclear Information System (INIS)

    A large amount of NOx, which is used in a reprocessing plant mainly as an oxidizing agent of Pu3+, eventually results in the formation of low-level radioactive sodium nitrate waste. Since NOx is generated by the reaction of sodium nitrite and nitric acid, non-radioactive sodium nitrate is also formed as a by-product. In order to reduce the amounts of radioactive and non-radioactive sodium nitrate wastes, a new method was examined to recover NOx for recycling from the off-gas of the denitrator of uranyl nitrate solution. Fundamental and consequent bench scale experiments showed that the vacuum pressure swing adsorption method, using combined silica-gel and clinoptilolite for water vapor removal and pentasil zeolite for NOx recovery, is applicable for this purpose. (author)

  20. Influences of Catalytic Combustion on the Ignition Timing and Emissions of HCCI Engines

    Institute of Scientific and Technical Information of China (English)

    ZENG Wen; XIE Mao-zhao

    2008-01-01

    The combustion processes of homogeneous charge compression ignition (HCCI) engines whose piston surfaces have been coated with catalyst (rhodium or platinum) were numerically investigated. A single-zone model and a multi-zone model were developed. The effects of catalytic combustion on the ignition timing of the HCCI engine were analyzed through the single-zone model. The results showed that the ignition timing of the HCCI engine was advanced by the catalysis. The effects of catalytic combustion on HC, CO and NOx emissions of the HCCI engine were analyzed through the multi-zone model. The results showed that the emissions of HC and CO (using platinum (Pt) as catalyst) were decreased, while the emissions of NOx were elevated by catalytic combustion. Compared with catalyst Pt, the HC emissions were lower with catalyst rhodium(Rh) on the piston surface, but the emissions of NOx and CO were higher.

  1. Role of Nox2 and p22phox in Persistent Postoperative Hypertension in Aldosterone-Producing Adenoma Patients after Adrenalectomy

    Directory of Open Access Journals (Sweden)

    Xiaojing Geng

    2016-01-01

    Full Text Available Adrenal aldosterone-producing adenoma (APA, producing the salt-retaining hormone aldosterone, commonly causes secondary hypertension, which often persists after unilateral adrenalectomy. Although persistent hypertension was correlated with residual hormone aldosterone, the in vivo mechanism remains unclear. NADPH oxidase is the critical cause of aldosterone synthesis in vitro. Nox2 and p22phox comprise the NADPH oxidase catalytic core, serving to initiate a reactive oxygen species (ROS cascade that may participate in the pathology. mRNAs of seven NADPH oxidase isoforms in APA were evaluated by RT-PCR and Q-PCR and their proteins by immunohistochemistry and Western blotting. NADPH oxidase activity was also detected. Nox2 and p22phox were especially abundant in APA. Particularly higher Nox2 and p22phox gene and protein levels were seen in APA than controls. Significant correlations between Nox2 mRNA and aldosterone synthase (CYP11B2 mRNA (R=0.66, P<0.01 and Nox2 protein and baseline plasma aldosterone concentration (PAC (R=0.503, P<0.01 were detected in APA; however, none were found between p22phox mRNA, CYP11B2 mRNA, p22phox protein, and baseline PAC. Importantly, we found that Nox2 localized specifically in hyperplastic zona glomerulosa cells. In conclusion, our results highlight that Nox2 and p22phox may be directly involved in pathological aldosterone production and zona glomerulosa cell proliferation after APA resection.

  2. Combining nonthermal plasma with perovskite-like catalyst for NOx storage and reduction.

    Science.gov (United States)

    Peng, Han Hsuan; Pan, Kuan Lun; Yu, Sheng Jen; Yan, Shaw Yi; Chang, Moo Been

    2016-10-01

    A new NOx storage and reduction (NSR) system is developed for NOx removal by combining perovskite-like catalyst with nonthermal plasma technology. In this hybrid system, catalyst is mainly used for oxidizing NO to NO2 and storing them, while nonthermal plasma is applied as a desorption-reduction step for converting NOx into N2. An innovative catalyst with a high NOx storage capacity and good reduction performance is developed by successive impregnation. The catalysts prepared with various metal oxides were investigated for NOx storage capacity (NSC) and NOx conversion. Characterization of the catalysts prepared reveals that addition of cobalt (Co) and potassium (K) considerably increases the performance for NSC. Results also show that SrKMn0.8Co0.2O4 supported on BaO/Al2O3 has good NSC (209 μmol/gcatalyst) for the gas stream containing 500 ppm NO and 5 % O2 with N2 as carrier gas. For plasma reduction process, NOx conversion achieved with SrKMn0.8Co0.2O4/BaO/Al2O3 reaches 81 % with the applied voltage of 12 kV and frequency of 6 kHz in the absence of reducing agents. The results indicate that performance of plasma reduction process (81 %) is better than that of thermal reduction (64 %). Additionally, mixed gases including 1 % CO, 1 % H2 and 1 % CH4, and 2 % H2O(g) are simultaneously introduced into the system to investigate the effect on NSR with plasma system and results indicate that performance of NSR with plasma can be enhanced. Overall, the hybrid system is promising to be applied for removing NOx from gas streams. Graphical abstract ᅟ.

  3. NOx CONTROL OPTIONS AND INTEGRATION FOR US COAL FIRED BOILERS

    Energy Technology Data Exchange (ETDEWEB)

    Mike Bockelie; Marc Cremer; Kevin Davis; Bob Hurt; Eric Eddings

    2001-01-31

    This is the second Quarterly Technical Report for DOE Cooperative Agreement No: DE-FC26-00NT40753. The goal of the project is to develop cost effective analysis tools and techniques for demonstrating and evaluating low NOx control strategies and their possible impact on boiler performance for firing US coals. The focus of our efforts during the last three months have been on: (1) Completion of a long term field test for Rich Reagent Injection (RRI) at the Conectiv BL England Station Unit No.1, a 130 MW Cyclone fired boiler; (2) Extending our Computational Fluid Dynamics (CFD) based NOx model to accommodate the chemistry for RRI in PC fired boilers; (3) Design improvements and calibration tests of the corrosion probe; and (4) Investigations on ammonia adsorption mechanisms and removal processes for Fly Ash.

  4. An overview of photocatalysis phenomena applied to NOx abatement.

    Science.gov (United States)

    Ângelo, Joana; Andrade, Luísa; Madeira, Luís M; Mendes, Adélio

    2013-11-15

    This review provides a short introduction to photocatalysis technology in terms of the present environmental remediation paradigm and, in particular, NOx photoabatement. The fundamentals of photoelectrochemical devices and the photocatalysis phenomena are reviewed, highlighting the main reaction mechanisms. The critical historical developments on heterogeneous photocatalysis are briefly discussed, giving particular emphasis to the pioneer works in this field. The third part of this work focus mainly on NOx removal technology considering topics such as: TiO2 photochemistry; effect of the operating conditions on the photocatalysis process; Langmuir-Hinshelwood modeling; TiO2 photocatalytic immobilization approaches; and their applications. The last section of the paper presents the main conclusions and perspectives on the opportunities related to this technology. PMID:24018117

  5. An overview of photocatalysis phenomena applied to NOx abatement.

    Science.gov (United States)

    Ângelo, Joana; Andrade, Luísa; Madeira, Luís M; Mendes, Adélio

    2013-11-15

    This review provides a short introduction to photocatalysis technology in terms of the present environmental remediation paradigm and, in particular, NOx photoabatement. The fundamentals of photoelectrochemical devices and the photocatalysis phenomena are reviewed, highlighting the main reaction mechanisms. The critical historical developments on heterogeneous photocatalysis are briefly discussed, giving particular emphasis to the pioneer works in this field. The third part of this work focus mainly on NOx removal technology considering topics such as: TiO2 photochemistry; effect of the operating conditions on the photocatalysis process; Langmuir-Hinshelwood modeling; TiO2 photocatalytic immobilization approaches; and their applications. The last section of the paper presents the main conclusions and perspectives on the opportunities related to this technology.

  6. IEA low NOx combustion project Stage III. Low NOx combustion and sorbent injection demonstration projects. V.2

    International Nuclear Information System (INIS)

    This report summarizes the main results from an IES project concerning the demonstration of low-NOx combustion and sorbent injection as techniques for the control of NOx and SOx emissions from pulverized coal fired utility boilers. The project has built upon information generated in two previous stages of activity, where NOx and SOx control processes were evaluated at both fundamental and pilot-scales. The concept for this stage of the project was for a unique collaboration, where the participating countries (Canada, Denmark and Sweden, together with the United States) have pooled information from full scale boiler demonstrations of low-NOx burner and sorbent injection technologies, and have jointly contributed to establishing a common basis for data evaluation. Demonstration testing was successfully carried out on five wall-fired commercial boiler systems which ranged in size from a 20 MW thermal input boiler used for district heating, up to a 300 MW electric utility boiler. All of these units were fired on high-volatile bituminous coals with sulfur contents ranging from 0.6-3.2 percent. At each site the existing burners were either modified or replaced to provide for low-NOx combustion, and provisions were made to inject calcium based sorbent materials into the furnace space for SO2 emission control. The results of sorbent injection testing showed moderate levels of SO2 removal which ranged from approximately 15 to 55 percent at an injected calcium to sulfur molar ratio to 2.0 and with boiler operation at nominal full load. Sulfur capture was found to depend upon the combined effects of parameters such as: sorbent type and reactivity; peak sorbent temperature; coal sulfur content; and the thermal characteristics of the boilers. (8 refs., 58 figs., 6 tabs.)

  7. Characterization of Truncated Tumor-Associated NADH Oxidase (ttNOX)

    Science.gov (United States)

    Karr, Laurel J.; Malone, Christine C.; Burk, Melissa; Moore, Blake P.; Achari, Aniruddha; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    Bacterial, plant and animal cells possess novel surface proteins that exhibit both NADH oxidation (NOX) or hydroquinone and protein disulfide-thiol interchange. These enzymatic activities alternate to yield oscillating patterns wjth period lengths of approximately 24 minutes. The catalytic period of NOX proteins are temperature compensated and gravity responsive. We report the cloning, expression and characterization of truncated tumor-associated NADH oxidase (ttNOX), in which the membrane spanning region has been deleted. The cDNA (originated from HeLa cells) was cloned into pET-34b and pET-14b (Novagen) vectors for E. coli expression. Optimized expression and purification protocols yielded greater than 300mg per liter of culture with greater than 95% purity. Circular dichroism data was collected from a 2.7mg/ml solution in a 0.1mm cuvette with variable scanning using an Olis RSM CD spectrophotometer. The ellipticity values were scanned from 190 to 260nm. The spectra recorded have characteristics for alpha proteins with band maxima at 216nm and a possible shoulder at 212nm at 12OC and 250 C. Protein crystal screens are in progress and, to date, only small crystals have been observed. The regular periodic oscillatory change in the ttNOX protein is indicative of a possible time-keeping functional role. A single protein possessing alternating catalytic activities, with a potential biological clock function, is unprecedented and structural determination is paramount to understanding this role.

  8. On the Effect of Preparation Methods of PdCe-MOR Catalysts as NOx CH4-SCR System for Natural Gas Vehicles Application

    Directory of Open Access Journals (Sweden)

    Acácio Nobre Mendes

    2015-10-01

    Full Text Available In the present work, the effect of several parameters involved in the preparation of PdCe-HMOR catalysts active for NOx selective catalytic reduction with methane (NOx CH4-SCR was studied. Results show that the catalytic performance of Pd-HMOR is better when palladium is introduced by ion-exchange, namely at room temperature. It was also shown that Pd loading does not influence the formation of cerium species, namely surface Ce4+ (CeO2 species and CeO2 species in interaction with Pd. However, when Ce is introduced before Pd, more surface CeO2 species are stabilized in the support and less CeO2 become in interaction with Pd, which results in a worse NOx CH4-SCR catalytic performance.

  9. Study on SCR De NOx mechanism through in situ electrical conductivity measurements on V2O5-WO3/TiO2 catalysts

    Institute of Scientific and Technical Information of China (English)

    HA Heon Phil; JUNG Soon Hyo; LEE Jun Yub; HONG Sung Ho

    2006-01-01

    V2O5-WO3/TiO2 catalysts were prepared by impregnation method and in situ electrical conductivity measurements were carried out to investigate the reaction mechanism for ammonia SCR (selective catalytic reduction) of NOx.The electrical conductivity change with ammonia supply and the increase of electrical conductivity were mainly caused by reduction of the labile surface oxygen.The electrical conductivity change of catalysts shows close relationship with the conversion rate of NOx.Variation of conversion rate in atmosphere without gaseous oxygen also supports that the labile lattice oxygen is indispensable in the initial stage of the de NOx reaction.These results suggest that the liable lattice oxygen acts decisive role in the de NOx mechanism.They also support that De NOx reaction occurs through the Eley-Rideal type mechanism.The amount of labile oxygen can be estimated from the measurement of electrical conductivity change for catalysts with ammonia supply.

  10. Hydrogen peroxide mediates the cell growth and transformation caused by the mitogenic oxidase Nox1

    OpenAIRE

    Arnold, Rebecca S.; Shi, Jing; Murad, Emma; Whalen, Anne M.; Sun, Carrie Q.; Polavarapu, Rathnagiri; Parthasarathy, Sampath; John A. Petros; Lambeth, J. David

    2001-01-01

    Nox1, a homologue of gp91phox, the catalytic moiety of the superoxide (O\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} \\begin{equation*}{\\mathrm{_{2}^{-}}}\\end{equation*}\\end{document})-generating NADPH oxidase of phagocytes, causes increased O\\documentclass[12pt]{minimal} \\usepackage{amsmath} ...

  11. Composite TiO{sub 2}/clays materials for photocatalytic NOx oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Todorova, N.; Giannakopoulou, T.; Karapati, S.; Petridis, D. [Institute of Nanoscience and Nanotechnology, NCSR “Demokritos”, P.O. Box 60037, 153 10, Ag. Paraskevi, Attiki (Greece); Vaimakis, T. [Department of Chemistry, University of Ioannina, P.O. Box 1186, 451 10, Ioannina (Greece); Trapalis, C., E-mail: trapalis@ims.demokritos.gr [Institute of Nanoscience and Nanotechnology, NCSR “Demokritos”, P.O. Box 60037, 153 10, Ag. Paraskevi, Attiki (Greece)

    2014-11-15

    Graphical abstract: - Highlights: • Clays-supported TiO{sub 2} photocatalysts are prepared by simple, scalable method. • Visible light active TiO{sub 2} is incorporated in hydrotalcite, talk and kunipia clays. • The alkali substrates facilitate the NOx adsorption to the photocatalytic surface. • Low-content TiO{sub 2} photocatalysts demonstrated high NOx oxidation activity. • Titania/hydrotalcite photocatalyst exhibited remarkable NOx removal activity. - Abstract: TiO{sub 2} photocatalyst received much attention for air purification applications especially for removal of air pollutants like NOx, VOCs etc. It has been established that the activity of the photocatalyst can be significantly enhanced by its immobilization onto suitable substrates like inorganic minerals, porous silica, hydroxyapatite, adsorbent materials like activated carbon, various co-catalysts such as semiconductors, graphene, reduced graphite oxide, etc. In the present work, photocatalytic composite materials consisted of mineral substrate and TiO{sub 2} in weight ratio 1:1 were manufactured and examined for oxidation and removal of nitric oxides NOx (NO and NO{sub 2}). Commercial titania P25 (Evonik-Degussa) and urea-modified P25 were used as photocatalytically active components. Inorganic minerals, namely kunipia, talk and hydrotalcite were selected as supporting materials due to their layered structure and expected high NOx adsorption capability. Al{sup 3+} and Ca{sup 2+} intercalation was applied in order to improve the dispersion of TiO{sub 2} and its loading into the supporting matrix. The X-ray diffraction analysis and Scanning Electron Microscopy revealed the binary structure of the composites and homogeneous dispersion of the photocatalyst into the substrates. The photocatalytic behavior of the materials in NOx oxidation and removal was investigated under UV and visible light irradiation. The composite materials exhibited superior photocatalytic activity than the bare titania

  12. Composite TiO2/clays materials for photocatalytic NOx oxidation

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Clays-supported TiO2 photocatalysts are prepared by simple, scalable method. • Visible light active TiO2 is incorporated in hydrotalcite, talk and kunipia clays. • The alkali substrates facilitate the NOx adsorption to the photocatalytic surface. • Low-content TiO2 photocatalysts demonstrated high NOx oxidation activity. • Titania/hydrotalcite photocatalyst exhibited remarkable NOx removal activity. - Abstract: TiO2 photocatalyst received much attention for air purification applications especially for removal of air pollutants like NOx, VOCs etc. It has been established that the activity of the photocatalyst can be significantly enhanced by its immobilization onto suitable substrates like inorganic minerals, porous silica, hydroxyapatite, adsorbent materials like activated carbon, various co-catalysts such as semiconductors, graphene, reduced graphite oxide, etc. In the present work, photocatalytic composite materials consisted of mineral substrate and TiO2 in weight ratio 1:1 were manufactured and examined for oxidation and removal of nitric oxides NOx (NO and NO2). Commercial titania P25 (Evonik-Degussa) and urea-modified P25 were used as photocatalytically active components. Inorganic minerals, namely kunipia, talk and hydrotalcite were selected as supporting materials due to their layered structure and expected high NOx adsorption capability. Al3+ and Ca2+ intercalation was applied in order to improve the dispersion of TiO2 and its loading into the supporting matrix. The X-ray diffraction analysis and Scanning Electron Microscopy revealed the binary structure of the composites and homogeneous dispersion of the photocatalyst into the substrates. The photocatalytic behavior of the materials in NOx oxidation and removal was investigated under UV and visible light irradiation. The composite materials exhibited superior photocatalytic activity than the bare titania under both types of irradiation. Significant visible

  13. Using Acetylene for Selective Catalytic Reduction of NO in Excess Oxygen

    Institute of Scientific and Technical Information of China (English)

    YU Shan-Shan; WANG Xin-Ping; WANG Chong; XU Yan

    2006-01-01

    Acetylene as a reducing agent for selective catalytic reduction of NO (C2H2-SCR) was investigated over a series of metal exchanged HY catalysts, in the reaction system of 0.16% NO, 0.08% C2H2, and 9.95% O2 (volume percent)in He. 75% of NO conversion to N2 with hydrocarbon efficiency about 1.5 was achieved over a Ce-HY catalyst around 300 ℃. The NO removal level was comparable with that of selective catalytic reduction of NOx by C3H6reported in literatures, although only one third of the reducing agent in carbon moles was used in the C2H2-SCR of NO. The protons in zeolite were crucial to the C2H2-SCR of NO, and the performance of HY in the reaction was significantly promoted by cerium incorporation into the zeolite. NO2 was proposed to be the intermediate of NO reduction to N2, and the oxidation of NO to NO2 was rate-determining step of the C2H2-SCR of NO over Ce-HY.The suggestion was well supported by the results of the NO oxidation with O2, and the C2H2 consumption under the conditions in the presence or absence of NO.

  14. NOx Direct Decomposition: Potentially Enhanced Thermodynamics and Kinetics on Chemically Modified Ferroelectric Surfaces

    Science.gov (United States)

    Kakekhani, Arvin; Ismail-Beigi, Sohrab

    2014-03-01

    NOx are regulated pollutants produced during automotive combustion. As part of an effort to design catalysts for NOx decomposition that operate in oxygen rich environment and permit greater fuel efficiency, we study chemistry of NOx on (001) ferroelectric surfaces. Changing the polarization at such surfaces modifies electronic properties and leads to switchable surface chemistry. Using first principles theory, our previous work has shown that addition of catalytic RuO2 monolayer on ferroelectric PbTiO3 surface makes direct decomposition of NO thermodynamically favorable for one polarization. Furthermore, the usual problem of blockage of catalytic sites by strong oxygen binding is overcome by flipping polarization that helps desorb the oxygen. We describe a thermodynamic cycle for direct NO decomposition followed by desorption of N2 and O2. We provide energy barriers and transition states for key steps of the cycle as well as describing their dependence on polarization direction. We end by pointing out how a switchable order parameter of substrate,in this case ferroelectric polarization, allows us to break away from some standard compromises for catalyst design(e.g. the Sabatier principle). This enlarges the set of potentially catalytic metals. Primary support from Toyota Motor Engineering and Manufacturing, North America, Inc.

  15. 40 CFR 97.23 - NOX Budget permit contents.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false NOX Budget permit contents. 97.23... (CONTINUED) FEDERAL NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS Permits § 97.23 NOX Budget permit contents. (a) Each NOX Budget permit will contain, in a format prescribed by the...

  16. 40 CFR 97.42 - NOX allowance allocations.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false NOX allowance allocations. 97.42... (CONTINUED) FEDERAL NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS NOX Allowance Allocations § 97.42 NOX allowance allocations. (a)(1) The heat input (in mmBtu) used for calculating...

  17. 40 CFR 96.42 - NOX allowance allocations.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false NOX allowance allocations. 96.42... (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS FOR STATE IMPLEMENTATION PLANS NOX Allowance Allocations § 96.42 NOX allowance allocations. (a)(1) The heat input (in mmBtu) used...

  18. 40 CFR 97.24 - NOX Budget permit revisions.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false NOX Budget permit revisions. 97.24... (CONTINUED) FEDERAL NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS Permits § 97.24 NOX Budget permit revisions. (a) For a NOX Budget source with a title V operating permit, except as...

  19. 40 CFR 96.11 - Alternate NOX authorized account representative.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Alternate NOX authorized account... PROGRAMS (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS FOR STATE IMPLEMENTATION PLANS NOX Authorized Account Representative for NOX Budget Sources § 96.11 Alternate...

  20. 40 CFR 96.23 - NOX Budget permit contents.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false NOX Budget permit contents. 96.23... (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS FOR STATE IMPLEMENTATION PLANS Permits § 96.23 NOX Budget permit contents. (a) Each NOX Budget permit (including any draft or...

  1. 40 CFR 96.25 - NOX Budget permit revisions.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false NOX Budget permit revisions. 96.25... (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS FOR STATE IMPLEMENTATION PLANS Permits § 96.25 NOX Budget permit revisions. (a) For a NOX Budget source with a title V operating...

  2. Air quality benefits of universal particle filter and NOx controls on diesel trucks

    Science.gov (United States)

    Tao, L.; Mcdonald, B. C.; Harley, R.

    2015-12-01

    Heavy-duty diesel trucks are a major source of black carbon/particulate matter and nitrogen oxide emissions on urban and regional scales. These emissions are relevant to both air quality and climate change. Since 2010 in the US, new engines are required to be equipped with emission control systems that greatly reduce both PM and NOx emissions, by ~98% relative to 1988 levels. To reduce emissions from the legacy fleet of older trucks that still remain on the road, regulations have been adopted in Califonia to accelerate the replacement of older trucks and thereby reduce associated emissions of PM and NOx. Use of diesel particle filters will be widespread by 2016, and universal use of catalytic converters for NOx control is required by 2023. We assess the air quality consequences of this clean-up effort in Southern California, using the Community Multiscale Air Quality model (CMAQ), and comparing three scenarios: historical (2005), present day (2016), and future year (2023). Emissions from the motor vehicle sector are mapped at high spatial resolution based on traffic count and fuel sales data. NOx emissions from diesel engines in 2023 are expected to decrease by ~80% compared to 2005, while the fraction of NOx emitted as NO2 is expected to increase from 5 to 18%. Air quality model simulations will be analyzed to quantify changes in NO2, black carbon, particulate matter, and ozone, both basin-wide and near hot spots such as ports and major highways.

  3. Co3O4 based catalysts for NO oxidation and NOx reduction in fast SCR process

    International Nuclear Information System (INIS)

    Reaction activities of several developed catalysts for NO oxidation and NOx (NO + NO2) reduction have been determined in a fixed bed differential reactor. Among all the catalysts tested, Co3O4 based catalysts are the most active ones for both NO oxidation and NOx reduction reactions even at high space velocity (SV) and low temperature in the fast selective catalytic reduction (SCR) process. Over Co3O4 catalyst, the effects of calcination temperatures, SO2 concentration, optimum SV for 50% conversion of NO to NO2 were determined. Also, Co3O4 based catalysts (Co3O4-WO3) exhibit significantly higher conversion than all the developed DeNOx catalysts (supported/unsupported) having maximum conversion of NOx even at lower temperature and higher SV since the mixed oxide Co-W nanocomposite is formed. In case of the fast SCR, N2O formation over Co3O4-WO3 catalyst is far less than that over the other catalysts but the standard SCR produces high concentration of N2O over all the catalysts. The effect of SO2 concentration on NOx reduction is found to be almost negligible may be due to the presence of WO3 that resists SO2 oxidation. (author)

  4. Nox reduction in the sintering process

    Institute of Scientific and Technical Information of China (English)

    Yan-guang Chen; Zhan-cheng Guo; Zhi Wang; Gen-sheng Feng

    2009-01-01

    A new process, NOx reduction with recycling flue gas and modifying coke breeze, was proposed. The effects of modified coke breeze and recycled flue gas on NOx reduction were investigated by sinter pot tests. The results show that the NOx reduction rate is over 10wt% in the sintering of modified coke breeze, the effects of the additives on NOx reduction are: CeO2CaOK2CO3.The NOx reduction rate increases with the amount of recycled flue gas, and is 22.35wt% in the sintering with recycling 30vo1% of the flue gas. When 30vo1% of the flue gas is recycled into the sintering of CeO2, CaO, and K2CO3 modified coke breeze, the NOx reduc-tion rates are 36.10wt%, 32.56wt%, and 32.17wt%, respectively.

  5. Impact of Aircraft NOx Emission on NOx and Ozone over China

    Institute of Scientific and Technical Information of China (English)

    刘煜; I.S.A.ISAKSEN; J.K.SUNDET; 周秀骥; 马建中

    2003-01-01

    A three-dimensional global chemistry transport model (OSLO CTM2) is used to investigate the impact of subsonic aircraft NOx emission on NOz and ozone over China in terms of a year 2000 scenario of subsonic aircraft NOx emission. The results show that subsonic aircraft NOx emission significantly affects northern China, which makes NOx at 250 hPa increase by about 50 pptv with the highest percentage of 60% in January, and leading to an ozone increase of 8 ppbv with 5% relative change in April. The NOx increase is mainly attributed to the transport process, but ozone increase is produced by the chemical process. The NOx increases by less than 10 pptv by virtue of subsonic aircraft NOx emission over China,and ozone changes less than 0.4 ppbv. When subsonic aircraft NOx emission over China is doubled, its influence is still relatively small.

  6. Recent advances in automotive catalysis for NOx emission control by small-pore microporous materials.

    Science.gov (United States)

    Beale, A M; Gao, F; Lezcano-Gonzalez, I; Peden, C H F; Szanyi, J

    2015-10-21

    The ever increasing demand to develop highly fuel efficient engines coincides with the need to minimize air pollution originating from the exhaust gases of internal combustion engines. Dramatically improved fuel efficiency can be achieved at air-to-fuel ratios much higher than stoichiometric. In the presence of oxygen in large excess, however, traditional three-way catalysts are unable to reduce NOx. Among the number of lean-NOx reduction technologies, selective catalytic reduction (SCR) of NOx by NH3 over Cu- and Fe-ion exchanged zeolite catalysts has been extensively studied over the past 30+ years. Despite the significant advances in developing a viable practical zeolite-based catalyst for lean NOx reduction, the insufficient hydrothermal stabilities of the zeolite structures considered cast doubts about their real-world applicability. During the past decade renewed interest in zeolite-based lean NOx reduction was spurred by the discovery of the very high activity of Cu-SSZ-13 (and the isostructural Cu-SAPO-34) in the NH3-SCR of NOx. These new, small-pore zeolite-based catalysts not only exhibited very high NOx conversion and N2 selectivity, but also exhibited exceptionally high hydrothermal stability at high temperatures. In this review we summarize the key discoveries of the past ∼5 years that led to the introduction of these catalysts into practical applications. This review first briefly discusses the structure and preparation of the CHA structure-based zeolite catalysts, and then summarizes the key learnings of the rather extensive (but not complete) characterisation work. Then we summarize the key findings of reaction kinetic studies, and provide some mechanistic details emerging from these investigations. At the end of the review we highlight some of the issues that still need to be addressed in automotive exhaust control catalysis. PMID:25913215

  7. Cyclone Boiler Field Testing of Advanced Layered NOx Control Technology in Sioux Unit 1

    Energy Technology Data Exchange (ETDEWEB)

    Marc A. Cremer; Bradley R. Adams

    2006-06-30

    A four week testing program was completed during this project to assess the ability of the combination of deep staging, Rich Reagent Injection (RRI), and Selective Non-Catalytic Reduction (SNCR) to reduce NOx emissions below 0.15 lb/MBtu in a cyclone fired boiler. The host site for the tests was AmerenUE's Sioux Unit 1, a 500 MW cyclone fired boiler located near St. Louis, MO. Reaction Engineering International (REI) led the project team including AmerenUE, FuelTech Inc., and the Electric Power Research Institute (EPRI). This layered approach to NOx reduction is termed the Advanced Layered Technology Approach (ALTA). Installed RRI and SNCR port locations were guided by computational fluid dynamics (CFD) based modeling conducted by REI. During the parametric testing, NOx emissions of 0.12 lb/MBtu were achieved consistently from overfire air (OFA)-only baseline NOx emissions of 0.25 lb/MBtu or less, when firing the typical 80/20 fuel blend of Powder River Basin (PRB) and Illinois No.6 coals. From OFA-only baseline levels of 0.20 lb/MBtu, NOx emissions of 0.12 lb/MBtu were also achieved, but at significantly reduced urea flow rates. Under the deeply staged conditions that were tested, RRI performance was observed to degrade as higher blends of Illinois No.6 were used. NOx emissions achieved with ALTA while firing a 60/40 blend were approximately 0.15 lb/MBtu. NOx emissions while firing 100% Illinois No.6 were approximately 0.165 lb/MBtu. Based on the performance results of these tests, economics analyses of the application of ALTA to a nominal 500 MW cyclone unit show that the levelized cost to achieve 0.15 lb/MBtu is well below 75% of the cost of a state of the art SCR.

  8. SELECTIVE NOx RECIRCULATION FOR STATIONARY LEAN-BURN NATURAL GAS ENGINES

    Energy Technology Data Exchange (ETDEWEB)

    Nigel Clark; Gregory Thompson; Richard Atkinson; Chamila Tissera; Matt Swartz; Emre Tatli; Ramprabhu Vellaisamy

    2005-01-01

    The research program conducted at the West Virginia University Engine and Emissions Research Laboratory (EERL) is working towards the verification and optimization of an approach to remove nitric oxides from the exhaust gas of lean burn natural gas engines. This project was sponsored by the US Department of Energy, National Energy Technology Laboratory (NETL) under contract number: DE-FC26-02NT41608. Selective NOx Recirculation (SNR) involves three main steps. First, NOx is adsorbed from the exhaust stream, followed by periodic desorption from the aftertreatment medium. Finally the desorbed NOx is passed back into the intake air stream and fed into the engine, where a percentage of the NOx is decomposed. This reporting period focuses on the NOx decomposition capability in the combustion process. Although researchers have demonstrated NOx reduction with SNR in other contexts, the proposed program is needed to further understand the process as it applies to lean burn natural gas engines. SNR is in support of the Department of Energy goal of enabling future use of environmentally acceptable reciprocating natural gas engines through NOx reduction under 0.1 g/bhp-hr. The study of decomposition of oxides of nitrogen (NOx) during combustion in the cylinder was conducted on a 1993 Cummins L10G 240 hp lean burn natural gas engine. The engine was operated at different air/fuel ratios, and at a speed of 800 rpm to mimic a larger bore engine. A full scale dilution tunnel and analyzers capable of measuring NOx, CO{sub 2}, CO, HC concentrations were used to characterize the exhaust gas. Commercially available nitric oxide (NO) was used to mimic the NOx stream from the desorption process through a mass flow controller and an injection nozzle. The same quantity of NOx was injected into the intake and exhaust line of the engine for 20 seconds at various steady state engine operating points. NOx decomposition rates were obtained by averaging the peak values at each set point minus

  9. The Gothenburg Protocol: NOx emissions problematic for Norway

    International Nuclear Information System (INIS)

    The Gothenburg Protocol concerns long-range air pollution and is a continuation of earlier protocols and agreements. Its recommendations are based on calculations of where the greatest possible health- and environmental impact is obtained per dollar invested. European countries have done much to reduce the emission of sulphur dioxide. Norway and most other countries, however, have difficulties reducing their emissions of nitrogen oxides. In Norway, the emission of sulphur dioxide must also be substantially reduced, as the tolerance limit for SO2 in nature is low. It is socio-economically profitable for Norway to conform to the Gothenburg Protocol. One of the largest environmental problems in Norway is acid rain and death of fish. Although it is difficult to calculate the exact values of fishing-lakes and of reduced health injuries when the emissions of harmful waste gases are reduced, the profit is very high. 90% of the SO2 pollution in Norway is long-range transported from abroad. Yet Norway must reduce the domestic emissions from 30 000 to 22 000 tonnes the next 10 years. Most of the present emission of SO2 in Norway comes from the production of metals. The reduction goal can be achieved by a combination of improving industrial processes, SO2 cleaning, and reducing the sulphur content of oil. In many European countries, the greatest problem is the increasing emission of NOx and formation of ozone at the ground, which is largely due to the rapidly increasing motor traffic. In Norway, most of the NOx emission comes from the coastal traffic and the fishing fleet, followed by the motor traffic, the petroleum industry and the processing industry. The most cost-effective NOx reductions can be obtained in the North Sea by installing low-NOx gas turbines. In ships, catalytic cleaning of NOx and engine improvements will contribute. On land, the goods traffic can be made more efficient. Most of the emission of ammonia comes from agriculture, where special measures are

  10. Statistical modeling of global soil NOx emissions

    Science.gov (United States)

    Yan, Xiaoyuan; Ohara, Toshimasa; Akimoto, Hajime

    2005-09-01

    On the basis of field measurements of NOx emissions from soils, we developed a statistical model to describe the influences of soil organic carbon (SOC) content, soil pH, land-cover type, climate, and nitrogen input on NOx emission. While also considering the effects of soil temperature, soil moisture change-induced pulse emission, and vegetation fire, we simulated NOx emissions from global soils at resolutions of 0.5° and 6 hours. Canopy reduction was included in both data processing and flux simulation. NOx emissions were positively correlated with SOC content and negatively correlated with soil pH. Soils in dry or temperate regions had higher NOx emission potentials than soils in cold or tropical regions. Needleleaf forest and agricultural soils had high NOx emissions. The annual NOx emission from global soils was calculated to be 7.43 Tg N, decreasing to 4.97 Tg N after canopy reduction. Global averages of nitrogen fertilizer-induced emission ratios were 1.16% above soil and 0.70% above canopy. Soil moisture change-induced pulse emission contributed about 4% to global annual NOx emission, and the effect of vegetation fire on soil NOx emission was negligible.

  11. Introduction of water to reduce NOx emissions

    OpenAIRE

    Axelsson, Martin

    2009-01-01

    Bakgrunden till detta examens arbete är behovet av att få lägre emissioner och då speciellt NOx emissioner. I detta arbete är olika NOx reduktions metoder beskrivna och utvärderade. Tyngdpunkten har lagts på de ”våta NOx reduktions teknologierna” och då speciellt teknologier för att befukta insugsluften. Detta arbete består av en litteratur studie, genomgång av test resultat från motor tester med dessa teknologier samt simuleringar. NOx reduktionen genom at introducera vatten eller vatten ång...

  12. 40 CFR 97.52 - NOX Allowance Tracking System responsibilities of NOX authorized account representative.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false NOX Allowance Tracking System responsibilities of NOX authorized account representative. 97.52 Section 97.52 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) FEDERAL NOX BUDGET TRADING PROGRAM AND...

  13. Diffuse Reflectance Infrared Fourier Transform Study of NOx Adsorption on CGO10 Impregnated with K2O or BaO

    DEFF Research Database (Denmark)

    Traulsen, Marie Lund; Härelind Ingelsten, H.; Kammer Hansen, Kent

    2012-01-01

    In the present work Diffuse Reflectance Infrared Fourier Transform (DRIFT) spectroscopy is applied to study the adsorption of NOx at 300-500 °C in different atmospheres on gadolinium doped ceria (CGO), an important material in electrodes investigated for electrochemical NOx removal. Furthermore......, the effect on the NOx adsorption when adding K2O or BaO to the CGO is investigated. The DRIFT study shows mainly the presence of nitrate species at 500 °C, while at lower temperature a diversity of adsorbed NOx species exists on the CGO. Presence of O2 is shown to have a strong effect on the adsorption of NO......, but no effect on the adsorption of NO2. Addition of K2O and BaO dramatically affects the NOx adsorption and the results also show that the adsorbed NOx species are mobile and capable of changing adsorption state in the investigated temperature range....

  14. Diesel NO(x) aftertreatment by combined process using temperature swing adsorption, NO(x) reduction by nonthermal plasma, and NO(x) recirculation: improvement of the recirculation process.

    Science.gov (United States)

    Yoshida, Keiichiro; Kuwahara, Takuya; Kuroki, Tomoyuki; Okubo, Masaaki

    2012-09-15

    NO(x) emitted from a stationary diesel engine generator was treated with a hybrid system comprising NO(x) reduction by nonthermal plasma (NTP) and temperature swing adsorption (TSA) driven by engine waste heat. TSA produces a low-volume gas mixture of N(2) and highly concentrated NO(x), which is effectively reduced by NTP treatment. Improved treatment performance and efficiency are achieved by re-injecting the NTP-treated gas mixture into the engine intake. The system comprises two switchable adsorption chambers; the operation of this system was simulated by using a one-chamber system. The maximum energy efficiency for NO(x) treatment is 200 g(NO(2))/kWh. The respective contributions of NTP and injection of N(2) and NO(x) to the performance were theoretically analyzed. The analysis predicts that high energy efficiency and high NO(x)-removal efficiency can be simultaneously achieved with this system but miniaturization of the adsorption chambers will be a challenge.

  15. The effect of Na2S2O8 oxidant on improving the efficiency of photo-catalytic process of nano-TiO2 immobilized on concrete in DB71 removal

    Directory of Open Access Journals (Sweden)

    Masoumeh Panbehkar Bishe

    2014-07-01

    Conclusion: Oxidant addition increased the dye removal efficiency and decreased total time for complete decolorization indicating the positive effect of oxidant on photocatalytic process in dye removal.

  16. Trends in catalytic NO decomposition over transition metal surfaces

    DEFF Research Database (Denmark)

    Falsig, Hanne; Bligaard, Thomas; Rass-Hansen, Jeppe;

    2007-01-01

    The formation of NOx from combustion of fossil and renewable fuels continues to be a dominant environmental issue. We take one step towards rationalizing trends in catalytic activity of transition metal catalysts for NO decomposition by combining microkinetic modelling with density functional...... theory calculations. We show specifically why the key problem in using transition metal surfaces to catalyze direct NO decomposition is their significant relative overbinding of atomic oxygen compared to atomic nitrogen....

  17. LIF diagnostics of NO molecules in atmospheric-pressure DC streamer coronas used for NOx abatement

    International Nuclear Information System (INIS)

    The main objective of the presented work was LIF visualization of NO density (two-dimensional distribution) and monitoring the process of NOx removal in various regions of the streamer corona discharge reactor through which a simulator of flue gas (air/NO) flowed

  18. Physico-Chemical and Structural Properties of DeNOx and SO2 Oxidation Catalysts

    DEFF Research Database (Denmark)

    Masters, Stephen Grenville; Oehlers, Cord; Nielsen, Kurt;

    1996-01-01

    Commercial catalysts for NOx removal and SO2 oxidation and their model systems have been investigated by spectroscopic, thermal, electrochemical and X-ray methods. Structural information on the vanadium complexes and compounds as well as physico-chemical properties for catalyst model systems have...... been obtained. The results are discussed in relation to proposed reaction mechanisms....

  19. 常温常压下等离子体催化脱除空气中的苯%Plasma-catalytic removal of benzene from atmospheric pressure air at normal temperature

    Institute of Scientific and Technical Information of China (English)

    丁慧贤; 张增凤; 徐占春

    2012-01-01

    苯是典型的室内空气污染物,严重影响人体健康。在大气压及35℃下,通过在催化剂上进行介质阻挡放电的方式,进行了等离子体一催化氧化脱除空气中苯的研究。当气体中C6H6的体积分数为103.5X10~、H:0的体积分数为1.0%、空气为平衡气,输入能量密度为114J/L,空速为16500h^-1时,苯的脱除率可达93.5%。而在同样实验条件下,单纯等离子体脱除苯和单纯催化氧化脱除苯的脱除率分别为62.8%和9.0%。这一实验结果说明,等离子体与Ag/CeO,催化剂在催化氧化空气中苯的过程中产生了协同效应,等离子体产生的活性自由基在Ag/CeO,催化剂催化氧化苯的氧化一还原循环过程中起到了至关重要的作用。%Aimed at addressing benzene (C6H6 ) , a typical indoor air pollutant threatening to cause serious health disorders in human beings, this paper reports plasma-catalytic oxidation of benzene in gas streams via dielectric barrier discharges over Ag/Ce02 pellets at atmospheric pressure and 35 ℃. A feed gas mixture of 103.5 x 10-6 C6H6, 1.0% H20 in air, GHSV of 16 500 h^-l, and input discharge energy density of 114 J/L contribute to the benzene removal rate of 93.5%. But the same experimental conditions

  20. Low NOx heavy fuel combustor concept program, phase 1

    Science.gov (United States)

    Cutrone, M. B.

    1981-01-01

    Combustion tests were completed with seven concepts, including three rich/lean concepts, three lean/lean concepts, and one catalytic combustor concept. Testing was conducted with ERBS petroleum distillate, petroleum residual, and SRC-II coal-derived liquid fuels over a range of operating conditions for the 12:1 pressure ratio General Electric MS7001E heavy-duty turbine. Blends of ERBS and SRC-II fuels were used to vary fuel properties over a wide range. In addition, pyridine was added to the ERBS and residual fuels to vary nitrogen level while holding other fuel properties constant. Test results indicate that low levels of NOx and fuel-bound nitrogen conversion can be achieved with the rich/lean combustor concepts for fuels with nitrogen contents up to 1.0% by weight. Multinozzle rich/lean Concept 2 demonstrated dry low Nox emissions within 10-15% of the EPA New Source Performance Standards goals for SRC-II fuel, with yields of approximately 15%, while meeting program goals for combustion efficiency, pressure drop, and exhaust gas temperature profile. Similar, if not superior, potential was demonstrated by Concept 3, which is a promising rich/lean combustor design.

  1. Selective NOx Recirculation for Stationary Lean-Burn Natural Gas Engines

    Energy Technology Data Exchange (ETDEWEB)

    Nigel Clark; Gregory Thompson; Richard Atkinson; Richard Turton; Chamila Tissera; Emre Tatli; Andy Zimmerman

    2005-12-28

    address modeling and preliminary design of the heat exchanger, demister and NOx sorbent chamber suitable for a given engine. A simplified linear driving force model was developed to predict NOx adsorption into the sorbent material as cooled exhaust passes over fresh sorbent material. This aspect of the research will continue into 2006, and the benefits and challenges of SNR will be compared with those of competing systems, such as Selective Catalytic Reduction. Chemical kinetic modeling using the CHEMKIN software package was extended in 2005 to the case of slightly rich burn with EGR. Simulations were performed at 10%, 20%, 30% and 40% of the intake air replaced with EGR. NOx decomposition efficiency was calculated at the point in time where 98% of fuel was consumed, which is believed to be a conservative approach. The modeling data show that reductions of over 70% are possible using the ''98% fuel burned'' assumption.

  2. Role of Nox2 and p22phox in Persistent Postoperative Hypertension in Aldosterone-Producing Adenoma Patients after Adrenalectomy.

    Science.gov (United States)

    Geng, Xiaojing; Yan, Li; Dong, Jun; Liang, Ying; Deng, Yajuan; Li, Ting; Luo, Tongfeng; Lin, Hailun; Zhang, Shaoling

    2016-01-01

    Adrenal aldosterone-producing adenoma (APA), producing the salt-retaining hormone aldosterone, commonly causes secondary hypertension, which often persists after unilateral adrenalectomy. Although persistent hypertension was correlated with residual hormone aldosterone, the in vivo mechanism remains unclear. NADPH oxidase is the critical cause of aldosterone synthesis in vitro. Nox2 and p22phox comprise the NADPH oxidase catalytic core, serving to initiate a reactive oxygen species (ROS) cascade that may participate in the pathology. mRNAs of seven NADPH oxidase isoforms in APA were evaluated by RT-PCR and Q-PCR and their proteins by immunohistochemistry and Western blotting. NADPH oxidase activity was also detected. Nox2 and p22phox were especially abundant in APA. Particularly higher Nox2 and p22phox gene and protein levels were seen in APA than controls. Significant correlations between Nox2 mRNA and aldosterone synthase (CYP11B2) mRNA (R = 0.66, P PAC) (R = 0.503, P PAC. Importantly, we found that Nox2 localized specifically in hyperplastic zona glomerulosa cells. In conclusion, our results highlight that Nox2 and p22phox may be directly involved in pathological aldosterone production and zona glomerulosa cell proliferation after APA resection. PMID:27057164

  3. Design of multi-shell Fe2O3@MnOx@CNTs for the selective catalytic reduction of NO with NH3: improvement of catalytic activity and SO2 tolerance

    Science.gov (United States)

    Cai, Sixiang; Hu, Hang; Li, Hongrui; Shi, Liyi; Zhang, Dengsong

    2016-02-01

    Manganese based catalysts are highly active in the NH3-SCR reaction for NOx removal. Unfortunately, manganese oxides can be easily deactivated by sulfur dioxide in the flow gas, which has become the main obstacle for their practical applications. To address this problem, we presented a green and facile method for the synthesis of multi-shell Fe2O3@MnOx@CNTs. The morphology and structural properties of the catalysts were systematically investigated. The results revealed that the MnOx@CNT core-shell structure was formed during the chemical bath deposition, while the outermost MnOx species were transformed to Fe2O3 after the galvanic replacement reaction. The formation of the multi-shell structure induced the enhancement of the active oxygen species, reducible species as well as adsorption of the reactants, which brought about excellent de-NOx performance. Moreover, the Fe2O3 shell could effectively suppress the formation of the surface sulfate species, leading to the desirable SO2 resistance to the multi-shell catalyst. Hence, the synthesis protocol could provide guidance for the preparation and elevation of manganese based catalysts.Manganese based catalysts are highly active in the NH3-SCR reaction for NOx removal. Unfortunately, manganese oxides can be easily deactivated by sulfur dioxide in the flow gas, which has become the main obstacle for their practical applications. To address this problem, we presented a green and facile method for the synthesis of multi-shell Fe2O3@MnOx@CNTs. The morphology and structural properties of the catalysts were systematically investigated. The results revealed that the MnOx@CNT core-shell structure was formed during the chemical bath deposition, while the outermost MnOx species were transformed to Fe2O3 after the galvanic replacement reaction. The formation of the multi-shell structure induced the enhancement of the active oxygen species, reducible species as well as adsorption of the reactants, which brought about excellent de-NOx

  4. Rho Kinase ROCK2 Mediates Acid-Induced NADPH Oxidase NOX5-S Expression in Human Esophageal Adenocarcinoma Cells

    Science.gov (United States)

    Cao, Weibiao

    2016-01-01

    Mechanisms of the progression from Barrett’s esophagus (BE) to esophageal adenocarcinoma (EA) are not fully understood. We have shown that NOX5-S may be involved in this progression. However, how acid upregulates NOX5-S is not well known. We found that acid-induced increase in NOX5-S expression was significantly decreased by the Rho kinase (ROCK) inhibitor Y27632 in BE mucosal biopsies and FLO-1 EA cells. In addition, acid treatment significantly increased the Rho kinase activity in FLO-1 cells. The acid-induced increase in NOX5-S expression and H2O2 production was significantly decreased by knockdown of Rho kinase ROCK2, but not by knockdown of ROCK1. Conversely, the overexpression of the constitutively active ROCK2, but not the constitutively active ROCK1, significantly enhanced the NOX5-S expression and H2O2 production. Moreover, the acid-induced increase in Rho kinase activity and in NOX5-S mRNA expression was blocked by the removal of calcium in both FLO-1 and OE33 cells. The calcium ionophore A23187 significantly increased the Rho kinase activity and NOX5-S mRNA expression. We conclude that acid-induced increase in NOX5-S expression and H2O2 production may depend on the activation of ROCK2, but not ROCK1, in EA cells. The acid-induced activation of Rho kinase may be mediated by the intracellular calcium increase. It is possible that persistent acid reflux present in BE patients may increase the intracellular calcium, activate ROCK2 and thereby upregulate NOX5-S. High levels of reactive oxygen species derived from NOX5-S may cause DNA damage and thereby contribute to the progression from BE to EA. PMID:26901778

  5. Rho Kinase ROCK2 Mediates Acid-Induced NADPH Oxidase NOX5-S Expression in Human Esophageal Adenocarcinoma Cells.

    Directory of Open Access Journals (Sweden)

    Jie Hong

    Full Text Available Mechanisms of the progression from Barrett's esophagus (BE to esophageal adenocarcinoma (EA are not fully understood. We have shown that NOX5-S may be involved in this progression. However, how acid upregulates NOX5-S is not well known. We found that acid-induced increase in NOX5-S expression was significantly decreased by the Rho kinase (ROCK inhibitor Y27632 in BE mucosal biopsies and FLO-1 EA cells. In addition, acid treatment significantly increased the Rho kinase activity in FLO-1 cells. The acid-induced increase in NOX5-S expression and H2O2 production was significantly decreased by knockdown of Rho kinase ROCK2, but not by knockdown of ROCK1. Conversely, the overexpression of the constitutively active ROCK2, but not the constitutively active ROCK1, significantly enhanced the NOX5-S expression and H2O2 production. Moreover, the acid-induced increase in Rho kinase activity and in NOX5-S mRNA expression was blocked by the removal of calcium in both FLO-1 and OE33 cells. The calcium ionophore A23187 significantly increased the Rho kinase activity and NOX5-S mRNA expression. We conclude that acid-induced increase in NOX5-S expression and H2O2 production may depend on the activation of ROCK2, but not ROCK1, in EA cells. The acid-induced activation of Rho kinase may be mediated by the intracellular calcium increase. It is possible that persistent acid reflux present in BE patients may increase the intracellular calcium, activate ROCK2 and thereby upregulate NOX5-S. High levels of reactive oxygen species derived from NOX5-S may cause DNA damage and thereby contribute to the progression from BE to EA.

  6. Heterogeneous Catalytic Ozonization of Sulfosalicylic Acid

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This paper describes the potential of heterogeneous catalytic ozonization of sulfo-salicylic acid (SSal). It was found that catalytic ozonization in the presence of Mn-Zr-O (a modified manganese dioxide supported on silica gel) had significantly enhanced the removal rate (72%) of total organic carbon (TOC) compared with that of ozonization alone (19%). The efficient removal rate of TOC was probably due to increasing the adsorption ability of catalyst and accelerating decomposition of ozone to produce more powerful oxidants than ozone.

  7. Design and testing of an independently controlled urea SCR retrofit system for the reduction of NOx emissions from marine diesels.

    Science.gov (United States)

    Johnson, Derek R; Bedick, Clinton R; Clark, Nigel N; McKain, David L

    2009-05-15

    Diesel engine emissions for on-road, stationary and marine applications are regulated in the United States via standards set by the Environmental Protection Agency (EPA). A major component of diesel exhaust that is difficult to reduce is nitrogen oxides (NOx). Selective catalytic reduction (SCR) has been in use for many years for stationary applications, including external combustion boilers, and is promising for NOx abatement as a retrofit for mobile applications where diesel compression ignition engines are used. The research presented in this paper is the first phase of a program focused on the reduction of NOx by use of a stand-alone urea injection system, applicable to marine diesel engines typical of work boats (e.g., tugs). Most current urea SCR systems communicate with engine controls to predict NOx emissions based on signals such as torque and engine speed, however many marine engines in use still employ mechanical injection technology and lack electronic communication abilities. The system developed and discussed in this paper controls NOx emissions independentof engine operating parameters and measures NOx and exhaust flow using the following exhaust sensor inputs: absolute pressure, differential pressure, temperature, and NOx concentration. These sensor inputs were integrated into an independent controller and open loop architecture to estimate the necessary amount of urea needed, and the controller uses pulse width modulation (PWM) to power an automotive fuel injector for airless urea delivery. The system was tested in a transient test cell on a 350 hp engine certified at 4 g/bhp-hr of NOx, with a goal of reducing the engine out NOx levels by 50%. NOx reduction capabilities of 41-67% were shown on the non road transient cycle (NRTC) and ICOMIA E5 steady state cycles with system optimization during testing to minimize the dilute ammonia slip to cycle averages of 5-7 ppm. The goal of 50% reduction of NOx can be achieved dependent upon cycle. Further

  8. Design and testing of an independently controlled urea SCR retrofit system for the reduction of NOx emissions from marine diesels.

    Science.gov (United States)

    Johnson, Derek R; Bedick, Clinton R; Clark, Nigel N; McKain, David L

    2009-05-15

    Diesel engine emissions for on-road, stationary and marine applications are regulated in the United States via standards set by the Environmental Protection Agency (EPA). A major component of diesel exhaust that is difficult to reduce is nitrogen oxides (NOx). Selective catalytic reduction (SCR) has been in use for many years for stationary applications, including external combustion boilers, and is promising for NOx abatement as a retrofit for mobile applications where diesel compression ignition engines are used. The research presented in this paper is the first phase of a program focused on the reduction of NOx by use of a stand-alone urea injection system, applicable to marine diesel engines typical of work boats (e.g., tugs). Most current urea SCR systems communicate with engine controls to predict NOx emissions based on signals such as torque and engine speed, however many marine engines in use still employ mechanical injection technology and lack electronic communication abilities. The system developed and discussed in this paper controls NOx emissions independentof engine operating parameters and measures NOx and exhaust flow using the following exhaust sensor inputs: absolute pressure, differential pressure, temperature, and NOx concentration. These sensor inputs were integrated into an independent controller and open loop architecture to estimate the necessary amount of urea needed, and the controller uses pulse width modulation (PWM) to power an automotive fuel injector for airless urea delivery. The system was tested in a transient test cell on a 350 hp engine certified at 4 g/bhp-hr of NOx, with a goal of reducing the engine out NOx levels by 50%. NOx reduction capabilities of 41-67% were shown on the non road transient cycle (NRTC) and ICOMIA E5 steady state cycles with system optimization during testing to minimize the dilute ammonia slip to cycle averages of 5-7 ppm. The goal of 50% reduction of NOx can be achieved dependent upon cycle. Further

  9. Roles for Nox4 in the contractile response of bovine pulmonary arteries to hypoxia

    OpenAIRE

    Ahmad, Mansoor; Kelly, Melissa R.; Zhao, Xiangmin; Kandhi, Sharath; Wolin, Michael S.

    2010-01-01

    Hypoxia appears to promote contraction [hypoxic pulmonary vasoconstriction (HPV)] of bovine pulmonary arteries (BPA) through removal of a peroxide-mediated relaxation. This study examines the roles of BPA Nox oxidases and mitochondria in the HPV response. Inhibitors of Nox2 (0.1 mM apocynin and 50 μM gp91-dstat) and mitochondrial electron transport (10 μM antimycin and rotenone) decreased superoxide generation in BPA without affecting contraction to 25 mM KCl or the HPV response. Transfection...

  10. COST-EFFECTIVE CONTROL OF NOx WITH INTEGRATED ULTRA LOW-NOx BURNERS AND SNCR

    Energy Technology Data Exchange (ETDEWEB)

    Hamid Farzan; Jennifer Sivy; Alan Sayre; John Boyle

    2003-07-01

    Under sponsorship of the Department of Energy's National Energy Technology Laboratory (NETL), McDermott Technology, Inc. (MTI), the Babcock & Wilcox Company (B&W), and Fuel Tech teamed together to investigate an integrated solution for NOx control. The system was comprised of B&W's DRB-4Z{trademark} low-NO{sub x} pulverized coal (PC) burner technology and Fuel Tech's NO{sub x}OUT{reg_sign}, a urea-based selective non-catalytic reduction (SNCR) technology. The technology's emission target is achieving 0.15 lb NO{sub x}/10{sup 6} Btu for full-scale boilers. Development of the low-NOx burner technology has been a focus in B&W's combustion program. The DRB-4Z{trademark} burner (see Figure 1.1) is B&W's newest low-NO{sub x} burner capable of achieving very low NO{sub x}. The burner is designed to reduce NO{sub x} by diverting air away from the core of the flame, which reduces local stoichiometry during coal devolatilization and, thereby, reduces initial NO{sub x} formation. Figure 1.2 shows the historical NO{sub x} emission levels from different B&W burners. Figure 1.2 shows that based on three large-scale commercial installations of the DRB-4Z{trademark} burners in combination with OFA ports, using Western subbituminous coal, the NO{sub x} emissions ranged from 0.16 to 0.18 lb/10{sup 6} Btu. It appears that with continuing research and development the Ozone Transport Rule (OTR) emission level of 0.15 lb NO{sub x}/10{sup 6} Btu is within the reach of combustion modification techniques for boilers using western U.S. subbituminous coals. Although NO{sub x} emissions from the DRB-4Z{trademark} burner are nearing OTR emission level with subbituminous coals, the utility boiler owners that use bituminous coals can still benefit from the addition of an SNCR and/or SCR system in order to comply with the stringent NO{sub x} emission levels facing them.

  11. NOX2-dependent regulation of inflammation.

    Science.gov (United States)

    Singel, Kelly L; Segal, Brahm H

    2016-04-01

    NADPH oxidase (NOX) isoforms together have multiple functions that are important for normal physiology and have been implicated in the pathogenesis of a broad range of diseases, including atherosclerosis, cancer and neurodegenerative diseases. The phagocyte NADPH oxidase (NOX2) is critical for antimicrobial host defence. Chronic granulomatous disease (CGD) is an inherited disorder of NOX2 characterized by severe life-threatening bacterial and fungal infections and by excessive inflammation, including Crohn's-like inflammatory bowel disease (IBD). NOX2 defends against microbes through the direct antimicrobial activity of reactive oxidants and through activation of granular proteases and generation of neutrophil extracellular traps (NETs). NETosis involves the breakdown of cell membranes and extracellular release of chromatin and neutrophil granular constituents that target extracellular pathogens. Although the immediate effects of oxidant generation and NETosis are predicted to be injurious, NOX2, in several contexts, limits inflammation and injury by modulation of key signalling pathways that affect neutrophil accumulation and clearance. NOX2 also plays a role in antigen presentation and regulation of adaptive immunity. Specific NOX2-activated pathways such as nuclear factor erythroid 2-related factor 2 (Nrf2), a transcriptional factor that induces antioxidative and cytoprotective responses, may be important therapeutic targets for CGD and, more broadly, diseases associated with excessive inflammation and injury.

  12. 40 CFR 96.82 - NOX authorized account representative.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false NOX authorized account representative... PROGRAMS (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS FOR STATE IMPLEMENTATION PLANS Individual Unit Opt-ins § 96.82 NOX authorized account representative. A unit for which...

  13. 40 CFR 97.82 - NOX authorized account representative.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false NOX authorized account representative... PROGRAMS (CONTINUED) FEDERAL NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS Individual Unit Opt-ins. § 97.82 NOX authorized account representative. A unit for which an application for a...

  14. Study of the "Fast SCR" -like mechanism of H2-assisted SCR of NOx with ammonia over Ag/Al2O3

    DEFF Research Database (Denmark)

    Doronkin, Dmitry E.; Fogel, Sebastian; Tamm, Stefanie;

    2012-01-01

    It is shown that Ag/Al2O3 is a unique catalytic system for H2-assisted selective catalytic reduction of NOx by NH3 (NH3-SCR) with both Ag and alumina being necessary components of the catalyst. The ability of Ag/Al2O3 and pure Al2O3 to catalyse SCR of mixtures of NO and NO2 by ammonia...... is demonstrated, the surface species occurring discussed, and a "Fast SCR" -like mechanism of the process is proposed. The possibility of catalyst surface blocking by adsorbed NOx and the influence of hydrogen on desorption of NOx were evaluated by FTIR and DFT calculations. © 2011 Elsevier B.V....

  15. Modeling analysis of urea direct injection on the NOx emission reduction of biodiesel fueled diesel engines

    International Nuclear Information System (INIS)

    Highlights: • The effects of urea direct injection on NOx emissions reduction was investigated. • Aqueous urea solution was proposed to be injected after the fuel injection process. • The optimized injection strategy achieved a reduction efficiency of 58%. • There were no severe impacts on the CO emissions and BSFC. - Abstract: In this paper, a numerical simulation study was conducted to explore the possibility of an alternative approach: direct aqueous urea solution injection on the reduction of NOx emissions of a biodiesel fueled diesel engine. Simulation studies were performed using the 3D CFD simulation software KIVA4 coupled with CHEMKIN II code for pure biodiesel combustion under realistic engine operating conditions of 2400 rpm and 100% load. The chemical behaviors of the NOx formation and urea/NOx interaction processes were modeled by a modified extended Zeldovich mechanism and urea/NO interaction sub-mechanism. To ensure an efficient NOx reduction process, various aqueous urea injection strategies in terms of post injection timing, injection angle, and injection rate and urea mass fraction were carefully examined. The simulation results revealed that among all the four post injection timings (10 °ATDC, 15 °ATDC, 20 °ATDC and 25 °ATDC) that were evaluated, 15 °ATDC post injection timing consistently demonstrated a lower NO emission level. The orientation of the aqueous urea injection was also shown to play a critical role in determining the NOx removal efficiency, and 50 degrees injection angle was determined to be the optimal injection orientation which gave the most NOx reduction. In addition, both the urea/water ratio and aqueous urea injection rate demonstrated important roles which affected the thermal decomposition of urea into ammonia and the subsequent NOx removal process, and it was suggested that 50% urea mass fraction and 40% injection rate presented the lowest NO emission levels. At last, with the optimized injection strategy, the

  16. A high-density ammonia storage/delivery system based on Mg(NH3)6Cl2 for SCR-DeNOx in vehicles

    DEFF Research Database (Denmark)

    Elmøe, Tobias Dokkedal; Sørensen, Rasmus Zink; Quaade, Ulrich;

    2006-01-01

    In this paper, we present a new benchmark for the automobile selective catalytic reduction of NO(x): Mg(NH(3))(6)Cl(2). This solid complex releases ammonia upon heating and can be compacted into a dense shape which is both easy to handle and safe. Furthermore, the material has a high volumetric a...

  17. Sulfur poisoning and regeneration of the Ag/γ-Al2O3 catalyst for H2-assisted SCR of NOx by ammonia

    DEFF Research Database (Denmark)

    Doronkin, Dmitry E.; Khan, Tuhin Suvra; Bligaard, Thomas;

    2012-01-01

    Sulfur poisoning and regeneration mechanisms for a 2% Ag/γ-Al2O3 catalyst for the H2-assisted selective catalytic reduction of NOx by NH3 are investigated. The catalyst has medium sulfur tolerance at low temperatures, however a good capability of regeneration at 670°C under lean conditions when H...

  18. Towards Ideal NOx and CO2 Emission Control Technology for Bio-Oils Combustion Energy System Using a Plasma-Chemical Hybrid Process

    Science.gov (United States)

    Okubo, M.; Fujishima, H.; Yamato, Y.; Kuroki, T.; Tanaka, A.; Otsuka, K.

    2013-03-01

    A pilot-scale low-emission boiler system consisting of a bio-fuel boiler and plasma-chemical hybrid NOx removal system is investigated. This system can achieve carbon neutrality because the bio-fuel boiler uses waste vegetable oil as one of the fuels. The plasma-chemical hybrid NOx removal system has two processes: NO oxidation by ozone produced from plasma ozonizers and NO2 removal using a Na2SO3 chemical scrubber. Test demonstrations of the system are carried out for mixed oils (mixture of A-heavy oil and waste vegetable oil). Stable combustion is achieved for the mixed oil (20 - 50% waste vegetable oil). Properties of flue gas—e.g., O2, CO2 and NOx—when firing mixed oils are nearly the same as those when firing heavy oil for an average flue gas flow rate of 1000 Nm3/h. NOx concentrations at the boiler outlet are 90 - 95 ppm. Furthermore, during a 300-min continuous operation when firing 20% mixed oil, NOx removal efficiency of more than 90% (less than 10 ppm NOx emission) is confirmed. In addition, the CO2 reduction when heavy oil is replaced with waste vegetable oil is estimated. The system comparison is described between the plasma-chemical hybrid NOx removal and the conventional technology.

  19. Towards Ideal NOx and CO2 Emission Control Technology for Bio-Oils Combustion Energy System Using a Plasma-Chemical Hybrid Process

    International Nuclear Information System (INIS)

    A pilot-scale low-emission boiler system consisting of a bio-fuel boiler and plasma-chemical hybrid NOx removal system is investigated. This system can achieve carbon neutrality because the bio-fuel boiler uses waste vegetable oil as one of the fuels. The plasma-chemical hybrid NOx removal system has two processes: NO oxidation by ozone produced from plasma ozonizers and NO2 removal using a Na2SO3 chemical scrubber. Test demonstrations of the system are carried out for mixed oils (mixture of A-heavy oil and waste vegetable oil). Stable combustion is achieved for the mixed oil (20 – 50% waste vegetable oil). Properties of flue gas—e.g., O2, CO2 and NOx—when firing mixed oils are nearly the same as those when firing heavy oil for an average flue gas flow rate of 1000 Nm3/h. NOx concentrations at the boiler outlet are 90 – 95 ppm. Furthermore, during a 300-min continuous operation when firing 20% mixed oil, NOx removal efficiency of more than 90% (less than 10 ppm NOx emission) is confirmed. In addition, the CO2 reduction when heavy oil is replaced with waste vegetable oil is estimated. The system comparison is described between the plasma-chemical hybrid NOx removal and the conventional technology.

  20. Sodium bicarbonate in-duct injection with sodium sulfate recovery for SO2/NOx control

    International Nuclear Information System (INIS)

    Dry sodium injection with sodium bicarbonate has been used commercially at industrial sites since the mid 1980's. In the past three years, five full scale commercial demonstrations have been completed on electric utility coal fired units. Up to 75% SO2 removal with 0-40% NOx removal has been achieved on units equipped with ESPs. Recent slip stream studies have proven up to 90% SO2 removal and 25% NOx removal when injection is ahead of a baghouse. If dry sodium bicarbonate sorbent injection technology is used prior to a retrofitted baghouse, but after an existing ESP the sodium sulfate by-product/flyash mixture in the baghouse is over 90% Na2SO4. Simple filtration and crystallization will yield a high value 99% + pure Na2SO4 for sale. In this application, no liquid discharge occurs and potentially no solids discharge, since flyash recovered from the filter is either recycled to the boiler with the coal stream or reinjected into the boiler. EPA IAPCS model Version 4 is modified to project costs for this SO2/NOx removal technology when couples with Na2SO4 recovery. In this paper an example is used to show hardware requirements, consumables accountability, by-product recovery rates, capital costs and levelized costs

  1. 40 CFR 96.388 - CAIR NOX Ozone Season allowance allocations to CAIR NOX Ozone Season opt-in units.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false CAIR NOX Ozone Season allowance allocations to CAIR NOX Ozone Season opt-in units. 96.388 Section 96.388 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX...

  2. 40 CFR 96.12 - Changing the NOX authorized account representative and the alternate NOX authorized account...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Changing the NOX authorized account representative and the alternate NOX authorized account representative; changes in the owners and operators. 96... (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS FOR STATE IMPLEMENTATION...

  3. 40 CFR 75.71 - Specific provisions for monitoring NOX and heat input for the purpose of calculating NOX mass...

    Science.gov (United States)

    2010-07-01

    ... and heat input for the purpose of calculating NOX mass emissions. 75.71 Section 75.71 Protection of... MONITORING NOX Mass Emissions Provisions § 75.71 Specific provisions for monitoring NOX and heat input for the purpose of calculating NOX mass emissions. (a) Coal-fired units. The owner or operator of a...

  4. Involvement of Rac1 in Activation of Multicomponent Nox1- and Nox3-Based NADPH Oxidases

    OpenAIRE

    Ueyama, Takehiko; Geiszt, Miklós; Leto, Thomas L.

    2006-01-01

    Several Nox family NADPH oxidases function as multicomponent enzyme systems. We explored determinants of assembly of the multicomponent oxidases Nox1 and Nox3 and examined the involvement of Rac1 in their regulation. Both enzymes are supported by p47phox and p67phox or homologous regulators called Noxo1 and Noxa1, although Nox3 is less dependent on these cofactors for activity. Plasma membrane targeting of Noxa1 depends on Noxo1, through tail-to-tail interactions between these proteins. Noxa1...

  5. Rise and fall of the NOx emissions trade; Opkomst en ondergang van NOx-emissiehandel

    Energy Technology Data Exchange (ETDEWEB)

    Van der Velde, R. [Royal Haskoning DHV, Amersfoort (Netherlands); Van der Kolk, J. [Van der Kolk Advies, Soest (Netherlands)

    2013-04-15

    In 2005, the Netherlands started NOx emission trading. In 2014 they are terminating these activities. Are they stopping because the targets have been realized? This article provides an overview of the developments and experiences that have ultimately led to the termination of the NOx emission trade in the Netherlands [Dutch] In 2005 is Nederland begonnen in NOx-emissiehandel. In 2014 stoppen we er weer mee. Stoppen we omdat de doelen zijn gehaald? Een overzicht wordt gegeven van de ontwikkelingen en ervaringen die uiteindelijk hebben geleid tot beeindiging van de NOx-emissiehandel in Nederland.

  6. Nox-2 Is a Modulator of Fibrogenesis in Kidney Allografts

    OpenAIRE

    Djamali, A; A Vidyasagar; Adulla, M.; Hullett, D.; Reese, S.

    2008-01-01

    We studied the role of classical phagocytic NADPH oxidase (Nox) in the pathogenesis of kidney allograft tubulointerstitial fibrosis. Immunofluorescence studies showed that Nox-2 and p22phox (electron transfer subunits of Nox) colocalized in the tubulointerstitium of human kidney allografts. Tubular Nox-2 also colocalized with α -SMA in areas of injury, suggestive of epithelial-to-mesenchymal transition (EMT). Interstitial macrophages (CD68+) and myofibroblasts (α -SMA+) expressed Nox-2 while ...

  7. Optimization of an electrochemical cell with an adsorption layer for NOx removal

    OpenAIRE

    Shao, Jing; Kammer Hansen, Kent

    2012-01-01

    The structure of a multilayer electrochemical cell with an adsorption layer was optimized by removing an yttriastabilized zirconia cover layer. It was found that the NOx removal properties of the electrochemical cell were dramatically enhanced through the optimization, especially under conditions of low voltage, intermediate temperature, and high O2 concentration. The pronounced increase in activity and selectivity for NOx decomposition after removing the ytrriastabilized zirconia cover layer...

  8. SELECTIVE CATALYTIC REDUCTION MERCURY FIELD SAMPLING PROJECT

    Science.gov (United States)

    A lack of data still exists as to the effect of selective catalytic reduction (SCR), selective noncatalytic reduction (SNCR), and flue gas conditioning on the speciation and removal of mercury (Hg) at power plants. This project investigates the impact that SCR, SNCR, and flue gas...

  9. Numerical analysis of NOx reduction for compact design in marine urea-SCR system

    Science.gov (United States)

    Choi, Cheolyong; Sung, Yonmo; Choi, Gyung Min; Kim, Duck Jool

    2015-11-01

    In order to design a compact urea selective catalytic reduction system, numerical simulation was conducted by computational fluid dynamics tool. A swirl type static mixer and a mixing chamber were considered as mixing units in the system. It had great influence on flow characteristics and urea decomposition into ammonia. The mixer caused flow recirculation and high level of turbulence intensity, and the chamber increased residence time of urea-water-solution injected. Because of those effects, reaction rates of urea decomposition were enhanced in the region. When those mixing units were combined, it showed the maximum because the recirculation zone was significantly developed. NH3 conversion was maximized in the zone due to widely distributed turbulence intensity and high value of uniformity index. It caused improvement of NOx reduction efficiency of the system. It was possible to reduce 55% length of the chamber and connecting pipe without decrease of NOx reduction efficiency.

  10. Study on Prompt NOx Emission in Boilers

    Institute of Scientific and Technical Information of China (English)

    ZhongB.J.; RoslyakovP.V.

    1996-01-01

    Experimental and theoretical investigation of prompt nitrogen oxides emission in flame of different gaseous fuels were carried out with purpose of minimizing total NOx yield.The effect of the following factors was determined:air excess from 0.3 to 1.1,flame temperature,heating flame rate,fuel content,It was found that ,if air excess was less than 0.65,some prompt NOx converted to N2 in consequence of reacting with hydrocarbon radicals.

  11. Correlating Engine NOx Emission with Biodiesel Composition

    Science.gov (United States)

    Jeyaseelan, Thangaraja; Mehta, Pramod Shankar

    2016-06-01

    Biodiesel composition comprising of saturated and unsaturated fatty acid methyl esters has a significant influence on its properties and hence the engine performance and emission characteristics. This paper proposes a comprehensive approach for composition-property-NOx emission analysis for biodiesel fuels and highlights the pathways responsible for such a relationship. Finally, a procedure and a predictor equation are developed for the assessment of biodiesel NOx emission from its composition details.

  12. Fuel Flexible, Low Emission Catalytic Combustor for Opportunity Fuel Applications

    Energy Technology Data Exchange (ETDEWEB)

    Eteman, Shahrokh

    2013-06-30

    Limited fuel resources, increasing energy demand and stringent emission regulations are drivers to evaluate process off-gases or process waste streams as fuels for power generation. Often these process waste streams have low energy content and/or highly reactive components. Operability of low energy content fuels in gas turbines leads to issues such as unstable and incomplete combustion. On the other hand, fuels containing higher-order hydrocarbons lead to flashback and auto-ignition issues. Due to above reasons, these fuels cannot be used directly without modifications or efficiency penalties in gas turbine engines. To enable the use of these wide variety of fuels in gas turbine engines a rich catalytic lean burn (RCL®) combustion system was developed and tested in a subscale high pressure (10 atm.) rig. The RCL® injector provided stability and extended turndown to low Btu fuels due to catalytic pre-reaction. Previous work has shown promise with fuels such as blast furnace gas (BFG) with LHV of 85 Btu/ft3 successfully combusted. This program extends on this work by further modifying the combustor to achieve greater catalytic stability enhancement. Fuels containing low energy content such as weak natural gas with a Lower Heating Value (LHV) of 6.5 MJ/m3 (180 Btu/ft3 to natural gas fuels containing higher hydrocarbon (e.g ethane) with LHV of 37.6 MJ/m3 (1010 Btu/ft3) were demonstrated with improved combustion stability; an extended turndown (defined as the difference between catalytic and non-catalytic lean blow out) of greater than 250oF was achieved with CO and NOx emissions lower than 5 ppm corrected to 15% O2. In addition, for highly reactive fuels the catalytic region preferentially pre-reacted the higher order hydrocarbons with no events of flashback or auto-ignition allowing a stable and safe operation with low NOx and CO emissions.

  13. The poisoning effect of potassium ions doped on MnOx/TiO2 catalysts for low-temperature selective catalytic reduction

    Science.gov (United States)

    Zhang, Liangjing; Cui, Suping; Guo, Hongxia; Ma, Xiaoyu; Luo, Xiaogen

    2015-11-01

    The poisoning of alkali metal on MnOx/TiO2 catalysts used for selective catalytic reduction (SCR) of NOx by NH3 was investigated. KNO3, KCl and K2SO4 were doped on MnOx/TiO2 catalysts by sol-gel method, respectively. The SCR activity of each catalyst was measured for the removal of NOx with NH3 in the temperature range 90-330 °C. The experimental results showed that catalyst with KNO3 have a stronger deactivation effect than other catalysts. The properties of the catalysts were characterized by XRD, BET, SEM, XPS, H2-TPR, NH3-TPD and in situ DRIFTS analyses. The characterized results indicated that KNO3, KCl and K2SO4 caused the similar decrease of specific surface area and pore volume, but the quantity of acid sites for KNO3-MnOx/TiO2 catalyst reduced sharply. The main reason for catalyst deactivation is attributed to two aspects: one was physical influences for the decrease of surface area and pore volume, another was chemical influences that the K+ ions decomposed by KNO3 neutralized Brønsted acid sites of catalyst and reduced their reducibility. The chemical influence played a leading role on the deactivation of catalysts.

  14. Contrasting intra- and extracellular distribution of catalytic ferrous iron in ovalbumin-induced peritonitis.

    Science.gov (United States)

    Ito, Fumiya; Nishiyama, Takahiro; Shi, Lei; Mori, Masahiko; Hirayama, Tasuku; Nagasawa, Hideko; Yasui, Hiroyuki; Toyokuni, Shinya

    2016-08-01

    Iron is an essential nutrient for every type of life on earth. However, excess iron is cytotoxic and can lead to an increased cancer risk in humans. Catalytic ferrous iron [Fe(II)] is an initiator of the Fenton reaction, which causes oxidative stress by generating hydroxyl radicals. Recently, it became possible to localize catalytic Fe(II) in situ with a turn-on fluorescent probe, RhoNox-1. Here, we screened each organ/cell of rats to globally evaluate the distribution of catalytic Fe(II) and found that eosinophils showed the highest abundance. In various cells, lysosomes were the major organelle, sharing ∼40-80% of RhoNox-1 fluorescence. We then used an ovalbumin-induced allergic peritonitis model to study the dynamics of catalytic Fe(II). Peritoneal lavage revealed that the total iron contents per cell were significantly decreased, whereas an increase in the number of inflammatory cells (macrophages, neutrophils, eosinophils and lymphocytes) resulted in an increased total iron content of the peritoneal inflammatory cells. Notably, macrophages, eosinophils and neutrophils exhibited significantly increased catalytic Fe(II) with increased DMT1 expression and decreased ferritin expression, though catalytic Fe(II) was significantly decreased in the peritoneal lavage fluid. In conclusion, catalytic Fe(II) in situ more directly reflects cellular activity and the accompanying pathology than total iron does. PMID:27262439

  15. DEVELOPMENT AND DEMONSTRATION OF NOVEL LOW-NOx BURNERS IN THE STEEL INDUSTRY

    Energy Technology Data Exchange (ETDEWEB)

    Cygan, David

    2006-12-28

    Gas Technology Institute (GTI), together with Hamworthy Peabody Combustion Incorporated (formerly Peabody Engineering Corporation), the University of Utah, and Far West Electrochemical have developed and demonstrated an innovative combustion system suitable for natural gas and coke-oven gas firing within the steel industry. The combustion system is a simple, low-cost, energy-efficient burner that can reduce NOx by more than 75%. The U.S. steel industry needs to address NOx control at its steelmaking facilities. A significant part of NOx emissions comes from gas-fired boilers. In steel plants, byproduct gases – blast furnace gas (BFG) and coke-oven gas (COG) – are widely used together with natural gas to fire furnaces and boilers. In steel plants, natural gas can be fired together with BFG and COG, but, typically, the addition of natural gas raises NOx emissions, which can already be high because of residual fuel-bound nitrogen in COG. The Project Team has applied its expertise in low-NOx burners to lower NOx levels for these applications by combining advanced burner geometry and combustion staging with control strategies tailored to mixtures of natural gas and byproduct fuel gases. These methods reduce all varieties of NOx – thermal NOx produced by high flame temperatures, prompt NOx produced by complex chain reactions involving radical hydrocarbon species and NOx from fuel-bound nitrogen compounds such as ammonia found in COG. The Project Team has expanded GTI’s highly successful low-NOx forced internal recirculation (FIR) burner, previously developed for natural gas-fired boilers, into facilities that utilize BFG and COG. For natural gas firing, these burners have been shown to reduce NOx emissions from typical uncontrolled levels of 80-100 vppm to single-digit levels (9 vppm). This is done without the energy efficiency penalties incurred by alternative NOx control methods, such as external flue gas recirculation (FGR), water injection, and selective non-catalytic

  16. Kinetic and spectroscopic study of catalysts for water-gas shift and nitrogen oxide removal

    Science.gov (United States)

    Kispersky, Vincent Frederick

    Nitrogen oxides (NOx) are formed in high temperature combustion processes such as in power generation and motor vehicles. Increasingly stringent regulation of these harmful emissions continues to drive interest in developing, understanding and studying new catalytic formulations for exhaust aftertreatment. For mobile sources, predominantly heavy duty diesel engines, selective catalytic reduction (SCR) with NH3 has become the principal means of NO x abatement. An alternative technology developed, but now surpassed by SCR, is NOx Storage Reduction (NSR) catalysis. Both technologies have been studied in our laboratory and are the basis for this dissertation. We studied seven different lean NOx trap (LNT) monolith formulations for NSR ranging from 0.6 to 6.2 wt.% Pt and 4 to 20 wt.% Ba loadings on γ-Al 2O3. The noble metal component of a LNT oxidizes NO to NO 2 aiding in the storage of NO2 on the alkaline earth component. Before the storage component saturates, a reductant such as H2 is introduced into the vehicular exhaust and the stored NOx is released and reduced to N2. Once the storage component is free of NOx, reductant flow is ceased and storage is begun anew. Our research focused on understanding the effects that CO2 and H2O have on the storage capacity of the LNT over short as well as extended periods of time. We found that for high Ba loadings, CO 2 had a consistently detrimental effect on the fast NOx storage capacity (NSC), defined as the amount of NOx the catalyst can store before 1% of the inlet NOx is measured in the reactor outlet. Over long NOx storage periods, CO2 continued to inhibit storage compared to the same catalyst in CO2 free conditions. On low loadings of Ba, however, the inhibition of CO2 was significantly reduced. We found that the loading dependent characteristics of the Ba phase affected the way in which CO2 adsorbed on the storage component, which greatly affected the stability of the species on lower Ba loadings. The less stable

  17. NOx CONTROL OPTIONS AND INTEGRATION FOR US COAL FIRED BOILERS

    Energy Technology Data Exchange (ETDEWEB)

    Mike Bockelie; Marc Cremer; Kevin Davis; Connie Senior; Bob Hurt; Eric Eddings; Larry Baxter

    2001-10-10

    This is the fifth Quarterly Technical Report for DOE Cooperative Agreement No: DE-FC26-00NT40753. The goal of the project is to develop cost effective analysis tools and techniques for demonstrating and evaluating low NOx control strategies and their possible impact on boiler performance for firing US coals. The Electric Power Research Institute (EPRI) is providing cofunding for this program. This program contains multiple tasks and good progress is being made on all fronts. Field tests for NOx reduction in a cyclone fired utility boiler due to using Rich Reagent Injection (RRI) have been started. CFD modeling studies have been started to evaluate the use of RRI for NOx reduction in a corner fired utility boiler using pulverized coal. Field tests of a corrosion monitor to measure waterwall wastage in a utility boiler have been completed. Computational studies to evaluate a soot model within a boiler simulation program are continuing. Research to evaluate SCR catalyst performance has started. A literature survey was completed. Experiments have been outlined and two flow reactor systems have been designed and are under construction. Commercial catalyst vendors have been contacted about supplying catalyst samples. Several sets of new experiments have been performed to investigate ammonia removal processes and mechanisms for fly ash. Work has focused on a promising class of processes in which ammonia is destroyed by strong oxidizing agents at ambient temperature during semi-dry processing (the use of moisture amounts less than 5 wt-%). Both ozone and an ozone/peroxide combination have been used to treat both basic and acidic ammonia-laden ashes.

  18. NOx production due to energetic particle precipitation in the MLT region - results from an ion-chemistry model

    Science.gov (United States)

    Nieder, Holger; Sinnhuber, Miriam

    2013-04-01

    The chemistry in the mesosphere/lower thermosphere (MLT) region is driven by forcing from solar radiation and energetic particles. The resulting ionisation, dissociation and excitation of the constituents lead to production of neutral reactive species such as NOx (N, NO, NO2) and HOx (H, OH, HO2), both directly from dissociation of neutrals and indirectly from subsequent ion-neutral reactions. As NOx is long-lived during polar winter, it can be transported down to the stratosphere and contribute to catalytic ozone depletion. To study the effective NOx production rates during an ionisation event, runs with a one-dimensional state-of-the-art ion chemistry model (UBIC) are carried out and analysed. The model starts with a neutral atmosphere and uses direct ion and neutral production rates from Porter et al. (1976) and Rusch et al. (1981), adapted for the MLT region. Including raw ionisation rates from external sources such as AIMOS is possible. The ion-neutral reactions in the charged atmosphere are computed until equilibrium is reached, resulting in an effective production rate including impact of ion-neutral reactions. The indirect NOx production rate is found to depend on atmospheric parameters such as pressure, temperature and the abundance of NOx, atomic oxygen and H2O. For the MLT region, this leads to an increasing amount of NOx per ionpair created with increasing altitude due to an increasing atomic oxygen VMR. Values of >1.8 NOx per ionpair can be obtained. The results are made available to a 3D Chemistry Transport Model using a database-approach and multilinear interpolation for readout. Efficiency of this approach and first results from a 3D CTM using the ion-chemistry results are discussed.

  19. NOx emissions from Euro IV busses with SCR systems associated with urban, suburban and freeway driving patterns.

    Science.gov (United States)

    Fu, Mingliang; Ge, Yunshan; Wang, Xin; Tan, Jianwei; Yu, Linxiao; Liang, Bin

    2013-05-01

    NOx and particulate matter (PM) emissions from heavy-duty diesel vehicles (HDVs) have become the most important sources of pollutants affecting urban air quality in China. In recent years, a series of emission control strategies and diesel engine polices have been introduced that require advanced emission control technology. China and Europe mostly have used Selective Catalytic Reduction (SCR) with urea to meet the Euro IV diesel engine emission standard. In this study, two Euro IV busses with SCR were tested by using potable emission measurement system (PEMS) to assess NOx emissions associated with urban, suburban and freeway driving patterns. The results indicated that with the SCR system, the urea injection time for the entire driving period increased with higher vehicle speed. For freeway driving, the urea injection time covered 71%-83% of the driving period; the NOx emission factors from freeway driving were lower than those associated with urban and suburban driving. Unfortunately, the NOx emission factors were 2.6-2.8-, 2.3-2.7- and 2.2-2.3-fold higher than the Euro IV standard limits for urban, suburban and freeway driving, respectively; NOx emission factors (in g/km and g/(kW·h)) from the original vehicles (without SCR) were higher than their corresponding vehicles with SCR for suburban and freeway driving. Compared with the IVE model results, the measured NOx emission factors were 1.60-1.16-, 1.77-1.27-, 2.49-2.44-fold higher than the NOx predicted by the IVE model for urban and suburban driving, respectively. Thus, an adjustment of emission factors is needed to improve the estimation of Euro IV vehicle emissions in China.

  20. Effect of SO2 on the Performance of Fe-Mo/ZSM-5 Catalyst for the Selective Catalytic Reduction of NOx with Ammonia%SO2对Fe-Mo/ZSM-5催化剂上NOx催化还原性能的影响

    Institute of Scientific and Technical Information of China (English)

    杨成武; 张倩; 黎俊; 常立亚; 李哲

    2016-01-01

    分别采用共浸渍法和气相离子交换法制备了Fe Mo/ZSM-5 (CI)和Fe-Mo/ZSM-5(VIE)样品,研究了SO2对Fe-Mo/ZSM-5催化剂上以NH3为还原剂的NOx-SCR反应的影响.同时利用暂态响应实验、SO2-TPD以及FT-IR等技术对SO2的影响行为进行了分析.结果发现,VIE样品较CI样品具有更好的SCR催化活性.SO2只在低于300℃时对Fe-Mo/ZSM-5催化剂的活性有影响,而在高于300℃对催化活性几乎没有影响,而且温度越高,SO2对催化剂活性的抑制作用越小.研究表明,SO2在低温下对催化活性的抑制作用主要来源于其在催化剂表面的吸附作用,SO2在催化剂表面形成吸附态SO42-离子,少量的硫酸盐沉积在催化剂表面,减少了催化剂表面活性中心的数量.

  1. 40 CFR 52.2237 - NOX RACT and NOX conformity exemption.

    Science.gov (United States)

    2010-07-01

    ... the Tennessee Department of Environment and Conservation on March 21, 1995, for the five county middle... 40 Protection of Environment 4 2010-07-01 2010-07-01 false NOX RACT and NOX conformity exemption. 52.2237 Section 52.2237 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)...

  2. A study on the pulse corona discharge for DeNOx

    International Nuclear Information System (INIS)

    Systems reducing nitrogen oxide (NOx) gas by using the pulsed corona discharge have been studied on the removal efficiency depending upon reactor types. Two reactors, wire-plate and wire-cylinder type reactors, have same electrode gap spacing and same residence time of the sample gas. The removable efficiency has been analyzed in terms of pulse peak voltage in the corona discharge and electron energy. Applied electric power and emission spectrum of the nitrogen molecular were measured in order to deduce the average electron energy. Change of chemical reaction in the discharge area has also been observed due to variation of pulse shape and the reactor geometry. From these, the effect of electrode on the characteristics of the pulsed corona and the energy efficiency for NOx removal have been investigated. Wire-cylinder type reactor seems to be more efficient by 85 percent more for removal NOx from the flue gas in the pulsed corona discharge systems with the following conditions: power = 2 watts, applied voltage = 14 kilo volts, gas flow rate = 31 lpm

  3. Synthesis and properties of nanostructured sol-gel sorbents for simultaneous removal of sulfur dioxide and nitrogen oxides from flue gas

    Science.gov (United States)

    Buelna Quijada, Genoveva

    2001-07-01

    Regenerative, alumina-supported, copper-based sorbent/catalysts provide a promising technique for simultaneous removal of SO2 and NO x from flue gas. These sorbents can remove over 90% of SO2 and 70+% of NOx while generating no wastes, reducing energy consumption, and producing valuable by-products. The lack of a cost-effective sorbent with low attrition rate and good reactivity has been the main hurdle to commercialization of this copper oxide process. Developing such a sorbent is the focus of this dissertation. This work examines using sol-gel techniques rather than traditional processes to produce gamma-alumina and copper coated 7-alumina granular sorbents. Important modifications to the established sol-gel synthesis process were made, which minimized generated wastes and reduced preparation time and sorbent cost. A laboratory scale semi-continuous process providing a basis for large-scale synthesis was developed. The effect of the copper content on the surface area and dispersion of the active species on sol-gel-derived sorbents coated by the one step and wet-impregnation methods was studied. The sol-gel-derived sorbents showed superior sulfation and regeneration properties than the existing commercial sorbents used in the copper oxide process in terms of sulfation capacity, fast regeneration, recovery of sorption capacity, and SO2 concentration in the regenerated effluent. The optimum temperature for NO reduction by NH3 over sol-gel-derived CuO/gamma-Al2O3 was found to be 350°C for both fresh and sulfated catalysts. This was also the optimum operating temperature for simultaneous removal of SO2 and NOx from simulated flue gas. At 350°C, the adsorption capacity of the sol-gel sorbent/catalyst was higher than UOP's sorbent, and very close to the capacity of ALCOA's sorbent, while the catalytic activity for NO reduction of the sol-gel-derived CuO/gamma-Al 2O3 sorbent fell between the commercial sorbents. The new mesoporous sol-gel-derived materials showed

  4. Selective catalytic oxidation of ammonia

    Energy Technology Data Exchange (ETDEWEB)

    Leppaelahti, J.; Koljonen, T. [VTT Energy, Espoo (Finland)

    1996-12-31

    In the combustion of fossil fuels, the principal source of nitrogen oxides is nitrogen bound in the fuel structure. In gasification, a large part of fuel nitrogen forms NH{sub 3}, which may form nitrogen oxides during gas combustion. If NH{sub 3} and other nitrogen species could be removed from hot gas, the NO emission could be considerably reduced. However, relatively little attention has been paid to finding new means of removing nitrogen compounds from the hot gasification gas. The possibility of selectively oxidizing NH{sub 3} to N{sub 2} in the hot gasification has been studied at VTT Energy. The largest NH{sub 3} reductions have been achieved by catalytic oxidation on aluminium oxides. (author) (4 refs.)

  5. Catalytic wet Air Oxidation of o-Chlorophenol in Wastewater

    Institute of Scientific and Technical Information of China (English)

    徐新华; 汪大翬

    2003-01-01

    Catalytic wet air oxidation (CWAO) was investigated in laboratory-scale experiments for the treatment of o-chlorophenol in wastewater. Experimental results showed that wet air oxidation (WAO) process in the absence of catalyst was also effective for o-chlorophenol in wastewater treatment. Up to 80% of the initial CODCr was removed by wet air oxidation at 270℃ with twice amount of the required stoichiometric oxygen supply. At temperature of 150℃, the removal rate of CODCr was only 30%. Fe2(SO4)3, CuSO4, Cu(NO3)2 and MnSO4 exhibited high catalytic activity. Higher removal rate of CODCr was obtained by CWAO. More than 96% of the initial CODCr was removed at 270℃ and 84.6%-93.6% of the initial CODCr was removed at 150℃. Mixed catalysts had better catalytic activity for the degradation of o-chlorophenol in wastewater.

  6. Identification of a Conserved Sequence in Flavoproteins Essential for the Correct Conformation and Activity of the NADH Oxidase NoxE of Lactococcus lactis ▿ †

    OpenAIRE

    Tachon, Sybille; Chambellon, Emilie; Yvon, Mireille

    2011-01-01

    Water-forming NADH oxidases (encoded by noxE, nox2, or nox) are flavoproteins generally implicated in the aerobic survival of microaerophilic bacteria, such as lactic acid bacteria. However, some natural Lactococcus lactis strains produce an inactive NoxE. We examined the role of NoxE in the oxygen tolerance of L. lactis in the rich synthetic medium GM17. Inactivation of noxE suppressed 95% of NADH oxidase activity but only slightly affected aerobic growth, oxidative stress resistance, and NA...

  7. Reactive Oxygen Species Derived from NOX3 and NOX5 Drive Differentiation of Human Oligodendrocytes

    Science.gov (United States)

    Accetta, Roberta; Damiano, Simona; Morano, Annalisa; Mondola, Paolo; Paternò, Roberto; Avvedimento, Enrico V.; Santillo, Mariarosaria

    2016-01-01

    Reactive oxygen species (ROS) are signaling molecules that mediate stress response, apoptosis, DNA damage, gene expression and differentiation. We report here that differentiation of oligodendrocytes (OLs), the myelin forming cells in the CNS, is driven by ROS. To dissect the OL differentiation pathway, we used the cell line MO3-13, which display the molecular and cellular features of OL precursors. These cells exposed 1–4 days to low levels of H2O2 or to the protein kinase C (PKC) activator, phorbol-12-Myristate-13-Acetate (PMA) increased the expression of specific OL differentiation markers: the specific nuclear factor Olig-2, and Myelin Basic Protein (MBP), which was processed and accumulated selectively in membranes. The induction of differentiation genes was associated with the activation of ERK1-2 and phosphorylation of the nuclear cAMP responsive element binding protein 1 (CREB). PKC mediates ROS-induced differentiation because PKC depletion or bis-indolyl-maleimide (BIM), a PKC inhibitor, reversed the induction of differentiation markers by H2O2. H2O2 and PMA increased the expression of membrane-bound NADPH oxidases, NOX3 and NOX5. Selective depletion of these proteins inhibited differentiation induced by PMA. Furthermore, NOX5 silencing down regulated NOX3 mRNA levels, suggesting that ROS produced by NOX5 up-regulate NOX3 expression. These data unravel an elaborate network of ROS-generating enzymes (NOX5 to NOX3) activated by PKC and necessary for differentiation of OLs. Furthermore, NOX3 and NOX5, as inducers of OL differentiation, represent novel targets for therapies of demyelinating diseases, including multiple sclerosis, associated with impairment of OL differentiation. PMID:27313511

  8. Reactive Oxygen Species Derived from NOX3 and NOX5 Drive Differentiation of Human Oligodendrocytes.

    Science.gov (United States)

    Accetta, Roberta; Damiano, Simona; Morano, Annalisa; Mondola, Paolo; Paternò, Roberto; Avvedimento, Enrico V; Santillo, Mariarosaria

    2016-01-01

    Reactive oxygen species (ROS) are signaling molecules that mediate stress response, apoptosis, DNA damage, gene expression and differentiation. We report here that differentiation of oligodendrocytes (OLs), the myelin forming cells in the CNS, is driven by ROS. To dissect the OL differentiation pathway, we used the cell line MO3-13, which display the molecular and cellular features of OL precursors. These cells exposed 1-4 days to low levels of H2O2 or to the protein kinase C (PKC) activator, phorbol-12-Myristate-13-Acetate (PMA) increased the expression of specific OL differentiation markers: the specific nuclear factor Olig-2, and Myelin Basic Protein (MBP), which was processed and accumulated selectively in membranes. The induction of differentiation genes was associated with the activation of ERK1-2 and phosphorylation of the nuclear cAMP responsive element binding protein 1 (CREB). PKC mediates ROS-induced differentiation because PKC depletion or bis-indolyl-maleimide (BIM), a PKC inhibitor, reversed the induction of differentiation markers by H2O2. H2O2 and PMA increased the expression of membrane-bound NADPH oxidases, NOX3 and NOX5. Selective depletion of these proteins inhibited differentiation induced by PMA. Furthermore, NOX5 silencing down regulated NOX3 mRNA levels, suggesting that ROS produced by NOX5 up-regulate NOX3 expression. These data unravel an elaborate network of ROS-generating enzymes (NOX5 to NOX3) activated by PKC and necessary for differentiation of OLs. Furthermore, NOX3 and NOX5, as inducers of OL differentiation, represent novel targets for therapies of demyelinating diseases, including multiple sclerosis, associated with impairment of OL differentiation. PMID:27313511

  9. Reduction of Stored NOx on Pt/Al?O? and Pt/BaO/Al?O? Catalysts with H? and CO

    International Nuclear Information System (INIS)

    In situ FTIR spectroscopy coupled with mass spectrometry, and time resolved X-ray diffraction were used to study the efficiency of nitrate reduction with CO and H? on Pt/Al?O? and Pt/BaO/Al?O? NOx storage-reduction (NSR) catalysts. Surface nitrates were generated by NO? adsorption and their reduction efficiencies were examined on the catalysts together with the analysis of the gas phase composition in the presence of the two different reductants. H? was found to be a more effective reducing agent than CO. In particular, the reduction of surface nitrates proceeds very efficiently with H? even at low temperatures (∼420 K). During reduction with CO, isocyanates were observed to form on every catalyst component. These surface isocyanates, however, readily react with water to form CO? and ammonia. The thus formed NH?, in turn, reacts with stored NOx at higher temperatures (>473K) to produce N?. In the absence of H?O, the NCO species are stable to high temperatures, and removed only from the catalyst when they react with NOx thermal decomposition products to form N? and CO?. The results of this study point to a complex reaction mechanism that involves the removal of surface oxygen atoms from the Pt particles by either H? or CO, the direct reduction of stored NOx with H? (low temperature NOx reduction), the formation and the subsequent hydrolysis of NCO species, as well as the direct reaction of NCO with decomposing NOx (high temperature NOx reduction)

  10. Adsorption of SOx and NOx in activated viscose fibers.

    Science.gov (United States)

    Plens, Ana Carolina O; Monaro, Daniel L G; Coutinho, Aparecido R

    2015-01-01

    SOx and NOx are emissions resulting from combustion processes and are the main agents that contribute to the formation of acid rain, which causes harm to humans and the environment. Several techniques for removing these pollutants are applied in i.e. oil refineries, thermoelectric that use petroleum oils and vehicular pollution. Among these, highlight the adsorption of contaminants by the usage of activated carbon fibers and activated carbon, which are characterized by high surface area and uniform distribution of pores, providing appropriate conditions for application in processes of removing environmental contaminants. In the present work, activated viscose fibers (AVF) were prepared and applied in adsorption experiments of NO and SO2. The materials produced showed high values of surface area, with a predominance of micro pores with diameters in the range of 1.0 nm. The AVF had satisfactory performance in the removal of contaminants and are compatible with other synthetic fibers. Thus, the formation of active sites of carbon provides contaminants adsorption, demonstrating that carbon fibers cloth can be applied for the removal of pollutants. PMID:25993357

  11. Adsorption of SOX and NOX in activated viscose fibers

    Directory of Open Access Journals (Sweden)

    Ana Carolina O. Plens

    2015-06-01

    Full Text Available SOx and NOx are emissions resulting from combustion processes and are the main agents that contribute to the formation of acid rain, which causes harm to humans and the environment. Several techniques for removing these pollutants are applied in i.e. oil refineries, thermoelectric that use petroleum oils and vehicular pollution. Among these, highlight the adsorption of contaminants by the usage of activated carbon fibers and activated carbon, which are characterized by high surface area and uniform distribution of pores, providing appropriate conditions for application in processes of removing environmental contaminants. In the present work, activated viscose fibers (AVF were prepared and applied in adsorption experiments of NO and SO2. The materials produced showed high values of surface area, with a predominance of micro pores with diameters in the range of 1.0 nm. The AVF had satisfactory performance in the removal of contaminants and are compatible with other synthetic fibers. Thus, the formation of active sites of carbon provides contaminants adsorption, demonstrating that carbon fibers cloth can be applied for the removal of pollutants.

  12. Toxic Gas Removal by Dielectric Discharge with Corona Effect

    International Nuclear Information System (INIS)

    In this work, a theoretical and experimental study on SO2 and NOx removal by non-thermal plasma technology, more specifically a dielectric barrier (DBD) discharge combined with the Corona effect, is presented. Results obtained from a theoretical study describe the chemical kinetic model of SO2 and NOx removal processes; the effect of OH radicals in removal of both gases is noteworthy. Experimental results of de-SO2 process are reported. Also, optical emission spectroscopy study was applied on some atomic helium lines to obtain temperature of electrons in the non-thermal plasma

  13. Recent advances in automotive catalysis for NOx emission control by small-pore microporous materials

    Energy Technology Data Exchange (ETDEWEB)

    Beale, Andrew M.; Gao, Feng; Lezcano-Gonzalez, Ines; Peden, Charles HF; Szanyi, Janos

    2015-10-05

    The ever increasing demand to develop highly fuel efficient engines coincides with the need to minimize air pollution originating from the exhaust gases of internal combustion engines. Dramatically improved fuel efficiency can be achieved at air-to-fuel ratios much higher than stoichiometric. In the presence of oxygen in large excess, however, traditional three-way catalysts are unable to reduce NOx. Among the number of lean-NOx reduction technologies, selective catalytic reduction (SCR) of NOx by NH3 over Cu- and Fe-ion exchanged zeolite catalysts has been extensively studied over the past 30+ years. Despite the significant advances in developing a viable practical zeolite-based catalyst for lean NOx reduction, the insufficient hydrothermal stabilities of the zeolite structures considered cast doubts about their real-world applicability. During the past decade a renewed interest in zeolite-based lean NOx reduction was spurred by the discovery of the very high activity of Cu-SSZ-13 (and the isostructural Cu-SAPO-34) in the NH3 SCR of NOx. These new, small-pore zeolite-based catalysts not only exhibited very high NOx conversion and N2 selectivity, but also exhibited exceptional high hydrothermal stability at high temperatures. In this review we summarize the key discoveries of the past ~5 years that lead to the introduction of these catalysts into practical application. The review first briefly discusses the structure and preparation of the CHA structure-based zeolite catalysts, and then summarizes the key learnings of the rather extensive (but not complete) characterisation work. Then we summarize the key findings of reaction kinetics studies, and provide some mechanistic details emerging from these investigations. At the end of the review we highlight some of the issues that are still need to be addressed in automotive exhaust control catalysis. Funding A.M.B. and I.L.G. would like to thank EPSRC for funding. F.G., C.H.F.P. and J.Sz. gratefully acknowledge

  14. NOx Removal and Effect of Adsorbate-Adsorbate Interactions

    DEFF Research Database (Denmark)

    Khan, Tuhin Suvra

    low-index metal surfaces. Furthermore, I have used DFT calculated adsorption and transition state energies coupled with a microkinetic model to study two industrially important catalytic reactions, NH3 oxidation and selective catalytic reduction of NOx, to obtain the catalytic trends and understand...... these challenges systematically and have developed some new methods and models to counter those challenges and obtain some general understanding of the catalytic process. I have developed an adsorbate-adsorbate interaction model to include the coverage dependency of the adsorption energy in kinetic models...

  15. Role of Nox4 and Nox2 in Hyperoxia-Induced Reactive Oxygen Species Generation and Migration of Human Lung Endothelial Cells

    OpenAIRE

    Pendyala, Srikanth; Gorshkova, Irina A.; Usatyuk, Peter V.; He, Donghong; Pennathur, Arjun; Lambeth, J. David; Thannickal, Victor J.; Natarajan, Viswanathan

    2009-01-01

    In vascular endothelium, the major research focus has been on reactive oxygen species (ROS) derived from Nox2. The role of Nox4 in endothelial signal transduction, ROS production, and cytoskeletal reorganization is not well defined. In this study, we show that human pulmonary artery endothelial cells (HPAECs) and human lung microvascular endothelial cells (HLMVECs) express higher levels of Nox4 and p22phox compared to Nox1, Nox2, Nox3, or Nox5. Immunofluorescence microscopy and Western blot a...

  16. Low NOx heavy fuel combustor concept program

    Science.gov (United States)

    White, D. J.; Kubasco, A. J.

    1982-01-01

    Three simulated coal gas fuels based on hydrogen and carbon monoxide were tested during an experimental evaluation with a rich lean can combustor: these were a simulated Winkler gas, Lurgi gas and Blue Water gas. All three were simulated by mixing together the necessary pure component species, to levels typical of fuel gases produced from coal. The Lurgi gas was also evaluated with ammonia addition. Fuel burning in a rich lean mode was emphasized. Only the Blue Water gas, however, could be operated in such fashion. This showed that the expected NOx signature form could be obtained, although the absolute values of NOx were above the 75 ppm goals for most operating conditions. Lean combustion produced very low NOx well below 75 ppm with the Winkler and Lurgi gases. In addition, these low levels were not significantly impacted by changes in operating conditions.

  17. NOx reduction in Opole power plant

    International Nuclear Information System (INIS)

    In 2008 PGE Elektrownia Opole ordered a 'turn-key' retrofit execution of the combustion system to reduce NOx emission at BP-1150 boiler. The project includes modifications of burners as a first stage, and then ROFA system installation for combustion optimization and primary reduction of NOx, and Rotamix system installation for the further, secondary NOx reduction. The condition to install ROFA and Rotamix systems was keeping the same parameters of the power unit operation, in particular CO emission level, fly ash LOI and bottom ash LOI, ammonia slip, ambient noise, boiler availability and efficiency, material wastage rate, steam flow rate and temperature, as well as consumption of urea, water, electricity and compressed air. The work for this project was performed by a consortium that included Nalco Mobotec, Remak-Rozruch (a Consortium Leader) and SEFAKO

  18. Confirmation of Isolated Cu2+ Ions in SSZ-13 Zeolite as Active Sites in NH3-Selective Catalytic Reduction

    NARCIS (Netherlands)

    Deka, U.; Juhin, A.F.; Eilertsen, E.A.; Emerich, H.; Green, M.A.; Korhonen, S.T.; Weckhuysen, B.M.; Beale, A.M.

    2012-01-01

    NH3-Selective Catalytic Reduction (NH3-SCR) is a widely used technology for NOx reduction in the emission control systems of heavy duty diesel vehicles. Copper-based ion exchanged zeolites and in particular Cu-SSZ-13 (CHA framework) catalysts show both exceptional activity and hydrothermal stability

  19. Detection of NADPH oxidase subunits NOX1 and NOX4 in lung adenocarcinoma A549 cells, and impact of NOX1 on Nrf2- and HIF-1-dependent gene regulation

    OpenAIRE

    Malec, Viktor

    2010-01-01

    NADPH Oxidase 1 und 4 sind ROS generierende Enzymkomplexe mit einer wichtigen Funktion in der Signaltransduktion. Die wesentlichen Untereinheiten sind NOX1 und NOX4. Die Immunodetektion von NOX1 und NOX4 ist problematisch. Proteinbanden mit verschiedenem Molekulargewicht wurden beschrieben. Diese Banden könnten verschiedene Splicevarianten, posttranslationale Modifikationen, proteolytische Spaltprodukte oder unspezifische Proteine darstellen. Daher sind gut validierte NOX1 ...

  20. Catalytic distillation structure

    Science.gov (United States)

    Smith, Jr., Lawrence A.

    1984-01-01

    Catalytic distillation structure for use in reaction distillation columns, a providing reaction sites and distillation structure and consisting of a catalyst component and a resilient component intimately associated therewith. The resilient component has at least about 70 volume % open space and being present with the catalyst component in an amount such that the catalytic distillation structure consist of at least 10 volume % open space.

  1. Catalytic combustor for hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Mercea, J.; Grecu, E.; Fodor, T.; Kreibik, S.

    1982-01-01

    The performance of catalytic combustors for hydrogen using platinum-supported catalysts is described. Catalytic plates of different sizes were constructed using fibrous and ceramic supports. The temperature distribution as well as the reaction efficiency as a function of the fuel input rate was determined, and a comparison between the performances of different plates is discussed.

  2. NOx processing on Solar gas turbines; Turbines, traitement des nox sur les turbines a gaz solar

    Energy Technology Data Exchange (ETDEWEB)

    Chausse, X. [Spie Trindel, 95 - Cergy (France). Service TAG

    1997-12-31

    The Solar Company, in cooperation with Tuma Turbomach, has developed the SoLoNOx combustion system with a dry, lean, premixed compound, allowing for reduced NOx and CO emission levels (respectively 42 ppmv and 50 ppmv at 15 pc O{sub 2}). The combustor size is larger than a conventional combustor in order to maintain combustion efficiency and reduce carbon monoxide levels. Leaner combustion occurs at lower temperatures which produce less nitrogen oxides but require more volume to complete the combustion process. New developments should allow for a further reduction of NOx level at 25 ppmv

  3. System Study of Rich Catalytic/Lean burn (RCL) Catalytic Combustion for Natural Gas and Coal-Derived Syngas Combustion Turbines

    Energy Technology Data Exchange (ETDEWEB)

    Shahrokh Etemad; Lance Smith; Kevin Burns

    2004-12-01

    Rich Catalytic/Lean burn (RCL{reg_sign}) technology has been successfully developed to provide improvement in Dry Low Emission gas turbine technology for coal derived syngas and natural gas delivering near zero NOx emissions, improved efficiency, extending component lifetime and the ability to have fuel flexibility. The present report shows substantial net cost saving using RCL{reg_sign} technology as compared to other technologies both for new and retrofit applications, thus eliminating the need for Selective Catalytic Reduction (SCR) in combined or simple cycle for Integrated Gasification Combined Cycle (IGCC) and natural gas fired combustion turbines.

  4. NOx control accomplishments and future challenges for coal-fired boilers

    International Nuclear Information System (INIS)

    Nitrogen oxide (NOx) control strategies and challenges for fossil-fuel power plants are outlined. The following topics are described: US laws on environmental protection; US coal-fired generating capacity; retrofit NOx controls for coal-fired boilers; low NOx cell burner; NOx compliance planning; retrofit NOx controls for coal-fired boilers; emerging NOx issues; regulatory; strategic; technology and cost

  5. Experimental Study on Emission Control of Premixed Catalytic Combustion of Natural Gas Using Preheated Air%使用加热空气的预混天然气催化燃烧的实验研究

    Institute of Scientific and Technical Information of China (English)

    许考; 刘中良; 何洪; 程水源; 马重芳

    2007-01-01

    In this paper the premixed catalytic combustion emissions such as CO, unburned hydrocarbon (UHC),NOx and the temperature distribution in the catalytic monolith with ultra low concentration of Pd were studied.Three types of monoliths were used for experiments and the temperature of preheated air was respectively 50℃,100℃ and 200℃. The results showed that preheated air made radial temperature in the catalytic monolith uniform which helped to avoid local hot spots so as to decrease NOx emission. The experiment also proved that the shorter monolith showed much better catalytic combustion performance than longer one and the temperature at the exit of the shorter monolith was relatively lower. On the contrary, the temperature was higher in the longer monolith and the lethal NOx emission was slightly increased.

  6. The effect of Na2S2O8 oxidant on improving the efficiency of photo-catalytic process of nano-TiO2 immobilized on concrete in DB71 removal

    OpenAIRE

    Masoumeh Panbehkar Bishe; Bita Ayati

    2014-01-01

    Background and Objective: Most of the dyes used in the textile industries can be toxic and carcinogenic. One of the suitable technologies to remove them is advanced oxidation processes. The main purpose of this study was to investigate the positive effect of adding oxidant Na2S2O8 to the photocatalytic process using TiO2 nano-particles immobilized on concrete and UV radiation for removal of Direct Blue71 dye. Materials and Methods: Concrete was covered by 40 g/m2 of TiO2 nanoparticles usin...

  7. Direct Measurements of NOx Produced by Lightning

    Science.gov (United States)

    Rahman, M.; Cooray, V.; Rakov, V. A.; Uman, M. A.; Liyanage, P.; Decarlo, B. A.; Jerauld, J.; Olsen, R. C.

    2006-12-01

    We present the first direct measurements of NOx generated by lightning. In July 2005, three negative lightning flashes were triggered using the rocket-and-wire technique at the International Center for Lightning Research and Testing (ICLRT) at Camp Blanding, Florida. The NOx produced by these three rocket- triggered flashes was measured, using the chemiluminescence method, by isolating a 3-cm long section of the lightning channel within a discharge chamber whose volume was 0.77 m3. We measured NOx individually for the first flash, which was triggered on July 15, and cumulatively for the other two flashes, which were triggered within about eleven minutes of each other on July 31. The July 15 flash contained only an initial- stage current and no return strokes. Each of the July 31 flashes contained an initial-stage current and either one or two return strokes. The initial-stage current in each case had a duration in the range from 260 to 360 ms, and one return stroke in each July 31 flash was followed by a continuing current whose duration was greater than 40 ms. The NOx production by the July 15 flash without return strokes (total charge transfer of 77 C) was 2.0×10^{22} molecules per meter of lightning channel, and that by the two July 31 flashes with return strokes (total charge transfer of 108 C) was 2.4×10^{22} molecules per meter. The NOx production per unit charge for these two measurements was similar: 2.6×1020 and 2.2×1020 molecules per meter per coulomb. It appears that the NOx production is primarily from long-duration, steady currents, as opposed to microsecond-scale impulsive return stroke currents. This observation implies that cloud discharges, which transfer, on average, larger charges than ground discharges, but do not contain return strokes (although they do contain typically shorter and presumably smaller amplitude microsecond-scale pulses) may be as effective as (or more effective than) cloud-to-ground discharges in producing NOx in the

  8. 40 CFR 86.327-79 - Quench checks; NOX analyzer.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Quench checks; NOX analyzer. 86.327-79... Quench checks; NOX analyzer. (a) Perform the reaction chamber quench check for each model of high vacuum... capillary, and if used, dilution capillary. (c) Quench check as follows: (1) Calibrate the NOX analyzer...

  9. 40 CFR 89.317 - NOX converter check.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false NOX converter check. 89.317 Section 89... Provisions § 89.317 NOX converter check. (a) Prior to its introduction into service, and monthly thereafter... of the NOX generator to the sample inlet of the oxides of nitrogen analyzer which has been set to...

  10. 40 CFR 90.319 - NOX converter check.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false NOX converter check. 90.319 Section 90... Provisions § 90.319 NOX converter check. (a) The efficiency of the converter used for the conversion of NO2... percent of the NO concentration). The NOX analyzer must be in the NO mode so that the span gas does...

  11. 40 CFR 91.319 - NOX converter check.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false NOX converter check. 91.319 Section 91...) CONTROL OF EMISSIONS FROM MARINE SPARK-IGNITION ENGINES Emission Test Equipment Provisions § 91.319 NOX... of the NO concentration). The NOX analyzer must be in the NO mode so that the span gas does not...

  12. 40 CFR 75.70 - NOX mass emissions provisions.

    Science.gov (United States)

    2010-07-01

    ... been measured and recorded by a certified NOX concentration monitoring system, or by an approved... and appendices A through G of this part applicable to NOX concentration, flow rate, NOX emission rate... SO2, CO2 and opacity monitoring, recordkeeping and reporting do not apply to units that are subject...

  13. 40 CFR 96.50 - NOX Allowance Tracking System accounts.

    Science.gov (United States)

    2010-07-01

    ... IMPLEMENTATION PLANS NOX Allowance Tracking System § 96.50 NOX Allowance Tracking System accounts. (a) Nature and... accordance with this subpart. (b) Nature and function of general accounts. Consistent with § 96.51(b), the... 40 Protection of Environment 20 2010-07-01 2010-07-01 false NOX Allowance Tracking System...

  14. 40 CFR 76.12 - Phase I NOX compliance extension.

    Science.gov (United States)

    2010-07-01

    ... vendors who are qualified to provide the services and low NOX burner technology designed to meet the... services and low NOX burner technology designed to meet the applicable emission limitation under § 76.5... of the low NOX burner technology designed to meet the applicable emission limitation under § 76.5...

  15. MULTISTAGED BURNER DESIGN FOR IN-FURNACE NOX CONTROL

    Science.gov (United States)

    The paper gives results of an evaluation of a multistage combustion modification design, combining two advanced NOx control technologies, on a pilot-scale (0.9 MW) package boiler simulator for in-furnace NOx control of high nitrogen fuel combustion applications. A low NOx precomb...

  16. 40 CFR 97.142 - CAIR NOX allowance allocations.

    Science.gov (United States)

    2010-07-01

    ... (CONTINUED) FEDERAL NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS CAIR NOX Allowance... cooling purposes through the sequential use of energy, the total heat energy (in Btu) of the steam... energy for industrial, commercial, heating, or cooling purposes through the sequential use of energy,...

  17. Alkali- and Sulfur-Resistant Tungsten-Based Catalysts for NOx Emissions Control.

    Science.gov (United States)

    Huang, Zhiwei; Li, Hao; Gao, Jiayi; Gu, Xiao; Zheng, Li; Hu, Pingping; Xin, Ying; Chen, Junxiao; Chen, Yaxin; Zhang, Zhaoliang; Chen, Jianmin; Tang, Xingfu

    2015-12-15

    The development of catalysts with simultaneous resistance to alkalis and sulfur poisoning is of great importance for efficiently controlling NOx emissions using the selective catalytic reduction of NOx with NH3 (SCR), because the conventional V2O5/WO3-TiO2 catalysts often suffer severe deactivation by alkalis. Here, we support V2O5 on a hexagonal WO3 (HWO) to develop a V2O5/HWO catalyst, which has exceptional resistance to alkali and sulfur poisoning in the SCR reactions. A 350 μmol g(-1) K(+) loading and the presence of 1,300 mg m(-3) SO2 do not almost influence the SCR activity of the V2O5/HWO catalyst, and under the same conditions, the conventional V2O5/WO3-TiO2 catalysts completely lost the SCR activity within 4 h. The strong resistance to alkali and sulfur poisoning of the V2O5/HWO catalysts mainly originates from the hexagonal structure of the HWO. The HWO allows the V2O5 to be highly dispersed on the external surfaces for catalyzing the SCR reactions and has the relatively smooth surfaces and the size-suitable tunnels specifically for alkalis' diffusion and trapping. This work provides a useful strategy to develop SCR catalysts with exceptional resistance to alkali and sulfur poisoning for controlling NOx emissions from the stationary source and the mobile source. PMID:26587749

  18. Modeling Species Inhibition of NO Oxidation in Urea-SCR Catalysts for Diesel Engine NOx Control

    Energy Technology Data Exchange (ETDEWEB)

    Devarakonda, Maruthi N.; Tonkyn, Russell G.; Tran, Diana N.; Lee, Jong H.; Herling, Darrell R.

    2011-04-20

    Urea-selective catalytic reduction (SCR) catalysts are regarded as the leading NOx aftertreatment technology to meet the 2010 NOx emission standards for on-highway vehicles running on heavy-duty diesel engines. However, issues such as low NOx conversion at low temperature conditions still exist due to various factors, including incomplete urea thermolysis, inhibition of SCR reactions by hydrocarbons and H2O. We have observed a noticeable reduction in the standard SCR reaction efficiency at low temperature with increasing water content. We observed a similar effect when hydrocarbons are present in the stream. This effect is absent under fast SCR conditions where NO ~ NO2 in the feed gas. As a first step in understanding the effects of such inhibition on SCR reaction steps, kinetic models that predict the inhibition behavior of H2O and hydrocarbons on NO oxidation are presented in the paper. A one-dimensional SCR model was developed based on conservation of species equations and was coded as a C-language S-function and implemented in Matlab/Simulink environment. NO oxidation and NO2 dissociation kinetics were defined as a function of the respective adsorbate’s storage in the Fe-zeolite SCR catalyst. The corresponding kinetic models were then validated on temperature ramp tests that showed good match with the test data. Such inhibition models will improve the accuracy of model based control design for integrated DPF-SCR aftertreatment systems.

  19. Development of selective catalytic oxidation (SCO) for NH{sub 3} and HCN removal from gasification gas; Selektiivisen katalyyttisen hapetusprosessin (SCO) kehittaeminen kaasutuskaasun NH{sub 3}:n ja HCN:n poistoon

    Energy Technology Data Exchange (ETDEWEB)

    Leppaelahti, J.; Koljonen, T.; Heiskanen, K. [VTT Energy, Espoo (Finland)

    1997-10-01

    In gasification, reactive nitrogen compounds (mainly NH{sub 3} and HCN) are formed from fuel nitrogen. If the gas containing NH{sub 3} is burned, a high NO{sub x} emission may be formed. The content of nitrogen compounds of the hot gasification gas could be reduced in Selective Catalytic Oxidation (SCO) process. In this process small amounts of reactive oxidisers are injected into the gas in order to convert NH{sub 3} to N{sub 2}. The utilization of SCO process together with low NO{sub x} burners in advanced gasification power stations might offer an alternative for flue gas treatment technologies like SCR (Selective Catalytic Reduction). In the earlier research, conditions were found, where oxidizers reacted selectively with ammonia in the gasification gas. Highest ammonia reduction took place in the aluminium oxide bed in the presence of NO and O{sub 2}. The aim of this study is to examine the reaction mechanism in order to be able to further evaluate the development possibilities of this kind process. The effect of composition and the amount of added oxidizer, the content of combustible gas components, space velocity, pressure and temperature will be studied. The experiments are carried out with the laboratory scale high pressure flow reactor of VTT Energy. Kinetic modelling of the experimental results is carried out in co-operation with the combustion chemistry group of Aabo Akademi. The aim of the modelling work is to bring insight to the gas-phase reactions that are important for the SCO-process. (orig.)

  20. A New Process Study on Comprehensive Utilization of NOx from Nitric Acid Plant

    Institute of Scientific and Technical Information of China (English)

    Zhou Hou-zhen; Liang Hua

    2003-01-01

    Based on studies of controlling NOx from nitric acid exhaust gas domestic and abroad, this paper has developed a new technique on removal of NOx and production of a by-product with high added value-- MnO2. Experiment shows, pyrolusite, whose valid composition is MnO2, of absorbing NOx has the following characteristics: quick, low cost, no secondary pollutant. Moreover, exhaust gas can attain the required standards. If the temperature of the pyrolusite serum is 30℃, pH=4, containing 90 g/L MnO2, the absorptivity for 3 000 mg/m3 NOx is 89.2%. Furthermore,few of the impurities in pyrolusite dissolve in the absorption mother solution. The purification cost of product is very low.The purity of end product MnO2 is more than 99. 995% after purifying. Therefore, it is workable for the new technique on economy and technology. There are also obvious environmental benefits and marked economic returns.

  1. A New Process Study on Comprehensive Utilization of NOx from Nitric Acid Plant

    Institute of Scientific and Technical Information of China (English)

    ZhouHou-zhen; LiangHua

    2003-01-01

    Based on studies of controlling NOx from nitric acid exhaust gas domestic and abroad, this paper has developed a new technique on removal of NOx and production of a by-product with high added value MnO2. Experiment shows, pyrolusite, whose valid composition is MnO2, of absorbing NOx has the following characteristics: quick, low cost, no secondary pollutant. Moreover, exhaust gas can attain the required standards. If the temperature of the pyrolusite serum is 30℃, pH=4, containing 90 g/L MnO2, the absorptivity for 3 000 mg/m3 NOx is 89.2%. Furthermore,few of the impurities in pyrolusite dissolve in the absorption mother solution. The purification cost of product is very low.The purity of end product MnO2 is more than 99. 995% after purifying. Therefore, it is workable for the new technique on economy and technology. There are also obvious environmental benefits and marked economic returns.

  2. Structural Insights into Nox4 and Nox2: Motifs Involved in Function and Cellular Localization ▿ †

    OpenAIRE

    von Löhneysen, Katharina; Noack, Deborah; Malcolm R. Wood; Friedman, Jeffrey S.; Knaus, Ulla G.

    2009-01-01

    Regulated generation of reactive oxygen species (ROS) is primarily accomplished by NADPH oxidases (Nox). Nox1 to Nox4 form a membrane-associated heterodimer with p22phox, creating the docking site for assembly of the activated oxidase. Signaling specificity is achieved by interaction with a complex network of cytosolic components. Nox4, an oxidase linked to cardiovascular disease, carcinogenesis, and pulmonary fibrosis, deviates from this model by displaying constitutive H2O2 production witho...

  3. Fabrication of doped Titania (TiO2) nanofibers to serve as catalysts in NH3-Selective CatalyticReduction (SCR)

    DEFF Research Database (Denmark)

    Marani, Debora; Silva, Rafael Hubert; Dankeaw, Apiwat;

    2016-01-01

    of the NOx in exhausts via the NH3 SelectiveCatalytic Reduction (SCR) method. By combining electrospinning and sol-gel chemistry, materials areprocessed as nanofibers with the catalytic components (e. g. V2O5-WO3) incorporated as dopants into thesupporting anatase phase (e. g TiO2). Remarkable high NOx...... conversion efficiencies are obtained andassociated with the unique features deriving from the synergism among the doping approach, the nanoscaleconfinement, and the nano-fibrous texture. A novel concept of self-supported, lightweight and ultra-compactdesign SCR reactor is defined....

  4. Development and test of a new catalytic converter for natural gas fuelled engine

    Indian Academy of Sciences (India)

    M A Kalam; H H Masjuki; M Redzuan; T M I Mahlia; M A Fuad; M Mohibah; K H Halim; A Ishak; M Khair; A Shahrir; A Yusoff

    2009-06-01

    This paper presents characteristics of a new catalytic converter (catco) to be used for natural gas fuelled engine. The catco were developed based on catalyst materials consisting of metal oxides such as titanium dioxide (TiO2) and cobalt oxide (CoO) with wire mesh substrate. Both of the catalyst materials (such as TiO2 and CoO) are inexpensive in comparison with conventional catalysts (noble metals) such as palladium or platinum. In addition, the noble metals such as platinum group metals are now identified as human health risk due to their rapid emissions in the environment from various resources like conventional catalytic converter, jewelers and other medical usages. It can be mentioned that the TiO2/CoO based catalytic converter and a new natural gas engine such as compressed natural gas (CNG) direct injection (DI) engine were developed under a research collaboration program. The original engine manufacture catalytic conveter (OEM catco) was tested for comparison purposes. The OEM catco was based on noble metal catalyst with honeycomb ceramic substrate. It is experimentally found that the conversion efficiencies of TiO2/CoO based catalytic converter are 93%, 89% and 82% for NOx, CO and HC emissions respectively. It is calculated that the TiO2/CoO based catalytic converter reduces 24%, 41% and 40% higher NOx, CO and HC emissions in comparison to OEM catco respectively. The objective of this paper is to develop a low-cost three way catalytic converter to be used with the newly developed CNG-DI engine. Detailed review on catalytic converter, low-cost catalytic converter development characteristics and CNGDI engine test results have been presented with discussions.

  5. Active sites in Cu-SSZ-13 deNOx catalyst under reaction conditions: a XAS/XES perspective

    Science.gov (United States)

    Lomachenko, Kirill A.; Borfecchia, Elisa; Bordiga, Silvia; Soldatov, Alexander V.; Beato, Pablo; Lamberti, Carlo

    2016-05-01

    Cu-SSZ-13 is a highly active catalyst for the NH3-assisted selective catalytic reduction (SCR) of the harmful nitrogen oxides (NOx, x=1, 2). Since the catalytically active sites for this reaction are mainly represented by isolated Cu ions incorporated into the zeolitic framework, element-selective studies of Cu local environment are crucial to fully understand the enhanced catalytic properties of this material. Herein, we highlight the recent advances in the characterization of the most abundant Cu-sites in Cu-SSZ-13 upon different reaction-relevant conditions made employing XAS and XES spectroscopies, complemented by computational analysis. A concise review of the most relevant literature is also presented.

  6. Measurements of NOx, acyl peroxynitrates, and NOy with automatic interference corrections using a NO2 analyzer and gas phase titration.

    Science.gov (United States)

    Hargrove, James; Zhang, Jingsong

    2008-04-01

    NO(2) analyzers are much more valuable if they can also measure NO since the two (NO+NO(2)=NO(x)) are often found together. NO can be quantitatively converted to NO(2) by reaction with ozone and subsequent thermal decomposition of the N(2)O(5) that may form from further oxidation. The conversion of NO, along with decomposition of N(2)O(5) and removal of the remaining unreacted ozone with a heated chamber, allows for quantitative determination of NO(x) using a NO(2) analyzer and the determination of decomposed acyl peroxynitrates. Ambient tests are performed to demonstrate these methods. PMID:18447567

  7. Preparation and characterization of VOx/TiO2 catalytic coatings on stainless steel plates for structured catalytic reactors.

    OpenAIRE

    Giornelli, Thierry; Löfberg, Axel; Bordes-Richard, Elisabeth

    2006-01-01

    1 The parameters to be controlled to coat metallic walls by VOx/TiO2 catalysts which are used in the mild oxidation of hydrocarbons and NOx abatement are studied. Stainless steel (316 L) was chosen because of its large application in industrial catalytic reactors. TiO2 films on stainless steel were obtained by dip-coating in two steps. Superficially oxidized plates were first dipped in Ti-alkoxide sol-gel to be coated by a very thin layer of TiO2. On this anchoring layer was then deposited a ...

  8. Low NOx gives a winning edge

    International Nuclear Information System (INIS)

    As regulations for low emissions from gas turbine power plants have become more stringent around the world during the past ten years, GE has steadily advanced its development of Dry Low NOx (DLN) combustion systems to meet or better those regulations. Pollution control without affecting plant performance, incurring large capital expenditure or increasing plant size has become the goal of equipment suppliers. (author)

  9. Alternative alkali resistant deNOx catalysts

    DEFF Research Database (Denmark)

    Putluru, Siva Sankar Reddy; Kristensen, Steffen Buus; Due-Hansen, Johannes;

    2012-01-01

    Alternative alkali resistant deNOx catalysts were prepared using three different supports ZrO2, TiO2 and Mordenite zeolite. The majority of the catalysts were prepared by incipient wetness impregnation of a commercial support, with vanadium, copper or iron precursor, one catalyst was prepared...

  10. THE NOX SYSTEM IN NUCLEAR WASTE

    Science.gov (United States)

    A collaborative program between ANL and PNNL is proposed to study the radiation, and radiation induced, chemistry of the NOx system in waste simulants. The study will develop a computer model providing predictive capabilities for future EM operations including the characterizatio...

  11. Solid State Electrochemical DeNOx

    DEFF Research Database (Denmark)

    Kammer Hansen, Kent

    2010-01-01

    The literature on direct electrochemical reduction of NOx in a solid state cell has been reviewed. It is shown that that the reduction of nitric oxide either occurs on the electrode or on the electrolyte if F-centers are formed. It is also shown that some oxide based electrodes has a high apparent...

  12. 40 CFR 97.388 - CAIR NOX Ozone Season allowance allocations to CAIR NOX Ozone Season opt-in units.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false CAIR NOX Ozone Season allowance allocations to CAIR NOX Ozone Season opt-in units. 97.388 Section 97.388 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) FEDERAL NOX BUDGET TRADING PROGRAM AND...

  13. A novel liquid system of catalytic hydrogenation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    On the basis that endothermic aqueous-phase reforming of oxygenated hydrocarbons for H2 production and exothermic liquid phase hydrogenation of organic compounds are carried out under extremely close conditions of temperature and pressure over the same type of catalyst, a novel liquid system of catalytic hydrogenation has been proposed, in which hydrogen produced from aqueous-phase reforming of oxygenated hydrocarbons is in situ used for liquid phase hydrogenation of organic compounds. The usage of active hydrogen generated from aqueous-phase reforming of oxygenated hydrocarbons for liquid catalytic hydrogenation of organic compounds could lead to increasing the selectivity to H2 in the aqueous-phase reforming due to the prompt removal of hydrogen on the active centers of the catalyst. Meanwhile, this novel liquid system of catalytic hydrogenation might be a potential method to improve the selectivity to the desired product in liquid phase catalytic hydrogenation of organic compounds. On the other hand, for this novel liquid system of catalytic hydrogenation, some special facilities for H2 generation, storage and transportation in traditional liquid phase hydrogenation industry process are yet not needed. Thus, it would simplify the working process of liquid phase hydrogenation and increase the energy usage and hydrogen productivity.

  14. NOx emission trade; stronger and better; NOx emissiehandel sterker en beter

    Energy Technology Data Exchange (ETDEWEB)

    Moons, C.; Van der Kolk, J. (eds.)

    2009-11-15

    There are various reasons why emission trade doesn't function as originally intended. NOx reduction measures are mostly realized through requirements in permits rather than through requirements in emission trade. A working Group has been founded by the Dutch ministry of Housing, Spatial Planning and the Environment (VROM), the Dutch ministry of Economic Affairs (EZ), the Confederation of Netherlands Industry and Employers (VNO-NCW) and the DCMR Environmental Protection Agency. The central questions of the working group were: determining the respective physical and legal room for NOx emission trade; identifying the points that need to be improved (system adjustments) in NOx emission trade; defining the trajectory for realizing and safeguarding these points; reaching consensus on these points and the follow-up trajectory among VROM, EZ and VNO-NCW. [Dutch] Emissiehandel werkt om verschillende redenen niet zoals oorspronkelijk is bedoeld. NOx reductiemaatregelen komen vooral tot stand door eisen in vergunningen in plaats van via eisen in het kader van emissiehandel. Er is een werkgroep in het leven geroepen van VROM, EZ, VNO-NCW en DCMR. De vraagstelling voor de werkgroep was: Het bepalen van de fysieke respectievelijk juridische ruimte voor NOx emissiehandel; het benoemen van de punten ter verbetering (systeemaanpassingen) van NOx emissiehandel; het definieren van een traject voor de realisatie en borging van die punten; het bereiken van consensus over deze punten en het vervolgtraject tussen VROM, EZ en VNO-NCW.

  15. NOX, NOX who is there?, The contribution of NADPH Oxidase to beta cell dysfunction.

    Directory of Open Access Journals (Sweden)

    David eTaylor-Fishwick

    2013-04-01

    Full Text Available Predictions of diabetes prevalence over the next decades warrant the aggressive discovery of new approaches to stop or reverse loss of functional beta cell mass. Beta cells are recognized to have a relatively high sensitivity to reactive oxygen species (ROS and become dysfunctional under oxidative stress conditions. New discoveries have identified NADPH oxidases in beta cells as contributors to elevated cellular ROS. Reviewed are recent reports that evidence a role for NADPH oxidase-1 (NOX-1 in beta cell dysfunction. NOX-1 is stimulated by inflammatory cytokines that are elevated in diabetes. First, regulation of cytokine-stimulated NOX-1 expression has been linked to inflammatory lipid mediators derived from 12-lipoxyganase activity. For the first time in beta cells these data integrate distinct pathways associated with beta cell dysfunction. Second, regulation of NOX-1 in beta cells involves feed-forward control linked to elevated ROS and Src-kinase activation. This potentially results in unbridled ROS generation and identifies candidate targets for pharmacologic intervention. Third, consideration is provided of new, first-in-class, selective inhibitors of NOX-1. These compounds could have an important role in assessing a disruption of NOX-1/ROS signaling as a new approach to preserve and protect beta cell mass in diabetes.

  16. Role of Nox2 in diabetic kidney disease

    OpenAIRE

    You, Young-Hyun; Okada, Shinichi; Ly, San; Jandeleit-Dahm, Karin; Barit, David; Namikoshi, Tamehachi; Sharma, Kumar

    2013-01-01

    NADPH oxidase (Nox) isoforms have been implicated in contributing to diabetic microvascular complications, but the functional role of individual isoforms in diabetic kidney are unclear. Nox2, in particular, is highly expressed in phagocytes and may play a key inflammatory role in diabetic kidney disease. To determine the role of Nox2, we evaluated kidney function and pathology in wild-type (WT; C57BL/6) and Nox2 knockout (KO) mice with type 1 diabetes. Diabetes was induced in male Nox2 KO and...

  17. CHARACTERIZATION OF CATALYTIC COMBUSTOR TURBULENCE AND ITS INFLUENCE ON VANE AND ENDWALL HEAT TRANSFER AND ENDWALL FILM COOLING

    Energy Technology Data Exchange (ETDEWEB)

    Forrest E. Ames

    2002-10-01

    Endwall heat transfer distributions taken in a large-scale low speed linear cascade facility are documented for mock catalytic and dry low NOx (DLN) combustion systems. Inlet turbulence levels range from about 1.0 percent for the mock Catalytic combustor condition to 14 percent for the mock dry low NOx combustor system. Stanton number contours are presented at both turbulence conditions for Reynolds numbers based on true chord length and exit conditions ranging from 500,000 to 2,000,000. Catalytic combustor endwall heat transfer shows the influence of the complex three-dimensional flow field, while the effects of individual vortex systems are less evident for the mock dry low NOx cases. Turbulence scales have been documented for both cases. Inlet boundary layers are relatively thin for the mock catalytic combustor case while inlet flow approximates a channel flow with high turbulence for the mock DLN combustor case. Inlet boundary layer parameters are presented across the inlet passage for the three Reynolds numbers and both the mock catalytic and DLN combustor inlet cases. Both midspan and 95 percent span pressure contours are included. This research provides a well-documented database taken across a range of Reynolds numbers and turbulence conditions for assessment of endwall heat transfer predictive capabilities.

  18. Selective Catalytic Reduction of NO with Methane

    Institute of Scientific and Technical Information of China (English)

    Xiang Gao; Qi Yu; Limin Chen

    2003-01-01

    The removal of nitrogen oxides from exhaust gases has attracted great attention in recent years, and many approaches have been developed depending on the application. Methane, the main component of natural gas, has great potential as a NO reductant. In this paper, a number of catalysts previous reported for this catalytic reduction of NO have been reviewed, including a direct comparison of the relative activities and effective factors of the catalysts. Reaction mechanisms have also been explored preliminarily.

  19. Building Selectivity for NO Sensing in a NOx Mixture with Sonochemically Prepared CuO Structures

    Directory of Open Access Journals (Sweden)

    Max R. Mullen

    2015-12-01

    Full Text Available Several technologies are available for decreasing nitrogen oxide (NOx emissions from combustion sources, including selective catalytic reduction methods. In this process, ammonia reacts with nitric oxide (NO and nitrogen dioxide (NO2. As the stoichiometry of the two reactions is different, electrochemical sensor systems that can distinguish between NO and NO2 in a mixture of these two gases are of interest. Since NO and NO2 can be brought to equilibrium, depending on the temperature and the surfaces that they are in contact with, the detection of NO and NO2 independently is a difficult problem and has not been solved to date. In this study, we explore a high surface area sonochemically prepared CuO as the resistive sensing medium. CuO is a poor catalyst for NOx equilibration, and requires temperatures of 500 C to bring about equilibration. Thus, at 300 C, NO and NO2 retain their levels after interaction with CuO surface. In addition, NO adsorbs more strongly on the CuO over NO2. Using these two concepts, we can detect NO with minimal interference from NO2, if the latter gas concentration does not exceed 20% in a NOx mixture over a range of 100–800 ppm. Since this range constitutes most of the range of total NOx concentrations in diesel and other lean burn engines, this sensor should find application in selective detection of NO in this combustion application. A limitation of this sensor is the interference with CO, but with combustion in excess air, this problem should be alleviated.

  20. Experimental Assessment of NOx Emissions from 73 Euro 6 Diesel Passenger Cars.

    Science.gov (United States)

    Yang, Liuhanzi; Franco, Vicente; Mock, Peter; Kolke, Reinhard; Zhang, Shaojun; Wu, Ye; German, John

    2015-12-15

    Controlling nitrogen oxides (NOx) emissions from diesel passenger cars during real-world driving is one of the major technical challenges facing diesel auto manufacturers. Three main technologies are available for this purpose: exhaust gas recirculation (EGR), lean-burn NOx traps (LNT), and selective catalytic reduction (SCR). Seventy-three Euro 6 diesel passenger cars (8 EGR only, 40 LNT, and 25 SCR) were tested on a chassis dynamometer over both the European type-approval cycle (NEDC, cold engine start) and the more realistic Worldwide harmonized light-duty test cycle (WLTC version 2.0, hot start) between 2012 and 2015. Most vehicles met the legislative limit of 0.08 g/km of NOx over NEDC (average emission factors by technology: EGR-only 0.07 g/km, LNT 0.04 g/km, and SCR 0.05 g/km), but the average emission factors rose dramatically over WLTC (EGR-only 0.17 g/km, LNT 0.21 g/km, and SCR 0.13 g/km). Five LNT-equipped vehicles exhibited very poor performance over the WLTC, emitting 7-15 times the regulated limit. These results illustrate how diesel NOx emissions are not properly controlled under the current, NEDC-based homologation framework. The upcoming real-driving emissions (RDE) regulation, which mandates an additional on-road emissions test for EU type approvals, could be a step in the right direction to address this problem. PMID:26580818

  1. Catalytic Functions of Standards

    NARCIS (Netherlands)

    K. Blind (Knut)

    2009-01-01

    textabstractThe three different areas and the examples have illustrated several catalytic functions of standards for innovation. First, the standardisation process reduces the time to market of inventions, research results and innovative technologies. Second, standards themselves promote the diffusi

  2. Understanding Automotive Exhaust Catalysts Using a Surface Science Approach: Model NOx Storage Materials

    Energy Technology Data Exchange (ETDEWEB)

    Szanyi, Janos; Yi, Cheol-Woo W.; Mudiyanselage, Kumudu K.; Kwak, Ja Hun

    2013-11-01

    of a BaCO3 layer that prevents to complete carbonation of the entire BaO film under the experimental conditions applied in these studies. However, these ‘‘carbonated’’ BaO layers readily react with NO2, and at elevated sample temperature even the carbonate layer is converted to nitrates. The importance of the metal oxide/metal interface in the chemistry on NOx storage-reduction catalysts was studied on BaO(\\1 ML)/Pt(111) reverse model catalysts. In comparison to the clean Pt(111), new oxygen adsorption phases were identified on the BaO/Pt(111) surface that can be associated with oxygen atoms strongly adsorbed on Pt atoms at the peripheries of BaO particles. A simple kinetic model developed helped explain the observed thermal desorption results. The role of the oxide/metal interface in the reduction of Ba(NO3)2 was also substantiated in experiments where Ba(NO3)2/O/Pt(111) samples were exposed to CO at elevated sample temperature. The catalytic decomposition of the nitrate phase occurred as soon as metal sites opened up by the removal of interfacial oxygen via CO oxidation from the O/Pt(111) surface. The temperature for catalytic nitrate reduction was found to be significantly lower than the onset temperature of thermal nitrate decomposition. We gratefully acknowledge the US Department of Energy (DOE), Office of Science, Division of Chemical Sciences, Geosciences, and Biosciences for the support of this work. The research described in this paper was performed at the Environmental Molecular Sciences Laboratory (EMSL), a national user facility sponsored by the DOE Office of Biological and Environmental Research and located at the Pacific Northwest National Laboratory (PNNL). PNNL is operated for the US DOE by Battelle under contract number DE-AC05-76RL01830.

  3. ULTRA LOW NOx INTEGRATED SYSTEM FOR NOx EMISSION CONTROL FROM COAL-FIRED BOILERS

    Energy Technology Data Exchange (ETDEWEB)

    Galen H. Richards; Charles Q. Maney; Richard W. Borio; Robert D. Lewis

    2002-12-30

    ALSTOM Power Inc.'s Power Plant Laboratories, working in concert with ALSTOM Power's Performance Projects Group, has teamed with the U.S. Department of Energy's National Energy Technology Laboratory (DOE NETL) to conduct a comprehensive study to develop/evaluate low-cost, efficient NOx control technologies for retrofit to pulverized coal fired utility boilers. The objective of this project was to develop retrofit NOx control technology to achieve less than 0.15 lb/MMBtu NOx (for bituminous coals) and 0.10 lb/MMBtu NOx (for subbituminous coals) from existing pulverized coal fired utility boilers at a cost which is at least 25% less than SCR technology. Efficient control of NOx is seen as an important, enabling step in keeping coal as a viable part of the national energy mix in this century, and beyond. Presently 57% of U.S. electrical generation is coal based, and the Energy Information Agency projects that coal will maintain a lead in U.S. power generation over all other fuel sources for decades (EIA 1998 Energy Forecast). Yet, coal-based power is being strongly challenged by society's ever-increasing desire for an improved environment and the resultant improvement in health and safety. The needs of the electric-utility industry are to improve environmental performance, while simultaneously improving overall plant economics. This means that emissions control technology is needed with very low capital and operating costs. This project has responded to the industry's need for low NOx emissions by evaluating ideas that can be adapted to present pulverized coal fired systems, be they conventional or low NOx firing systems. The TFS 2000{trademark} firing system has been the ALSTOM Power Inc. commercial offering producing the lowest NOx emission levels. In this project, the TFS 2000{trademark} firing system served as a basis for comparison to other low NOx systems evaluated and was the foundation upon which refinements were made to further

  4. NOx abatement in the exhaust of lean-burn natural gas engines over Ag-supported γ-Al2O3 catalysts

    Science.gov (United States)

    Azizi, Y.; Kambolis, A.; Boréave, A.; Giroir-Fendler, A.; Retailleau-Mevel, L.; Guiot, B.; Marchand, O.; Walter, M.; Desse, M.-L.; Marchin, L.; Vernoux, P.

    2016-04-01

    A series of Ag catalysts supported on γ-Al2O3, including two different γ-Al2O3 supports and various Ag loadings (2-8 wt.%), was prepared, characterized (SEM, TEM, BET, physisorption, TPR, NH3-TPD) and tested for the selective catalytic reduction of NOx by CH4 for lean-burn natural gas engines exhausts. The catalysts containing 2 wt.% Ag supported on γ-Al2O3 were found to be most efficient for the NOx reduction into N2 with a maximal conversion of 23% at 650 °C. This activity was clearly linked with the ability of the catalyst to concomitantly produce CO, via the methane steam reforming, and NO2. The presence of small AgOx nanoparticles seems to be crucial for the methane activation and NOx reduction.

  5. Deactivation mechanism of potassium on the V₂O₅/CeO₂ catalysts for SCR reaction: acidity, reducibility and adsorbed-NOx.

    Science.gov (United States)

    Peng, Yue; Li, Junhua; Huang, Xu; Li, Xiang; Su, Wenkang; Sun, Xiaoxu; Wang, Dezhi; Hao, Jiming

    2014-04-15

    A series of V2O5/CeO2 catalysts with different potassium loadings were prepared to investigate alkali deactivations for selective catalytic reduction of NOx with NH3. An alkali poisoning mechanism could be attributed to surface acidity, reducibility, and NOx adsorption/desorption behaviors. The detailed factors are as follows: (1) decrease of surface acidity suppresses NH3 adsorption by strong bonding of alkali to vanadia (major factor); (2) low reducibility prohibits NH3 activation and NO oxidation by formation bonding of alkali to vanadia and ceria (important factor); (3) active NOx(-) species at low temperature diminish because of coverage of alkali on the surfaces (minor factor); and (4) stable, inactive nitrate species at high temperature increase by generating new basic sites (important factor).

  6. Catalytic Ozonation of Phenolic Wastewater: Identification and Toxicity of Intermediates

    OpenAIRE

    Mahdi Farzadkia; Yousef Dadban Shahamat; Simin Nasseri; Amir Hossein Mahvi; Mitra Gholami; Ali Shahryari

    2014-01-01

    A new strategy in catalytic ozonation removal method for degradation and detoxification of phenol from industrial wastewater was investigated. Magnetic carbon nanocomposite, as a novel catalyst, was synthesized and then used in the catalytic ozonation process (COP) and the effects of operational conditions such as initial pH, reaction time, and initial concentration of phenol on the degradation efficiency and the toxicity assay have been investigated. The results showed that the highest catal...

  7. Development of Catalytic Cooking Plates

    Energy Technology Data Exchange (ETDEWEB)

    Hjelm, Anna-Karin; Silversand, Fredrik [CATATOR AB, Lund (Sweden); Tena, Emmanuel; Berger, Marc [Gaz de France (France)

    2004-04-01

    Gas catalytic combustion for gas stoves or cooking plates (closed catalytic burner system with ceramic plates) is a very promising technique in terms of ease of cleaning, power modulation and emissions. Previous investigations show that wire mesh catalysts, prepared and supplied by Catator AB (CAT), seem to be very well suited for such applications. Beside significantly reducing the NOx-emissions, these catalysts offer important advantages such as good design flexibility, low pressure drop and high heat transfer capacity, where the latter leads to a quick thermal response. Prior to this project, Gaz de France (GdF) made a series of measurements with CAT's wire mesh catalysts in their gas cooking plates and compared the measured performance with similar results obtained with theirs cordierite monolith catalysts. Compared to the monolith catalyst, the wire mesh catalyst was found to enable very promising results with respect to both emission levels (<10 mg NO{sub x} /kWh, <5 mg CO/kWh) and life-time (>8000 h vs. 700 h at 200 kW/m{sup 2}). It was however established that the radiation and hence, the thermal efficiency of the cooking plate, was significantly less than is usually measured in combination with the monolith (15 % vs. 32 %). It was believed that the latter could be improved by developing new burner designs based on CAT's wire mesh concept. As a consequence, a collaboration project between GdF, CAT and the Swedish Gas Technology AB was created. This study reports on the design, the construction and the evaluation of new catalytic burners, based on CAT's wire mesh catalysts, used for the combustion of natural gas in gas cooking stoves. The evaluation of the burners was performed with respect to key factors such as thermal efficiency, emission quality and pressure drop, etc, by the use of theoretical simulations and experimental tests. Impacts of parameters such as the the wire mesh number, the wire mesh structure (planar or folded), the

  8. Methods of using structures including catalytic materials disposed within porous zeolite materials to synthesize hydrocarbons

    Science.gov (United States)

    Rollins, Harry W.; Petkovic, Lucia M.; Ginosar, Daniel M.

    2011-02-01

    Catalytic structures include a catalytic material disposed within a zeolite material. The catalytic material may be capable of catalyzing a formation of methanol from carbon monoxide and/or carbon dioxide, and the zeolite material may be capable of catalyzing a formation of hydrocarbon molecules from methanol. The catalytic material may include copper and zinc oxide. The zeolite material may include a first plurality of pores substantially defined by a crystal structure of the zeolite material and a second plurality of pores dispersed throughout the zeolite material. Systems for synthesizing hydrocarbon molecules also include catalytic structures. Methods for synthesizing hydrocarbon molecules include contacting hydrogen and at least one of carbon monoxide and carbon dioxide with such catalytic structures. Catalytic structures are fabricated by forming a zeolite material at least partially around a template structure, removing the template structure, and introducing a catalytic material into the zeolite material.

  9. Catalytic ignition of light hydrocarbons

    Institute of Scientific and Technical Information of China (English)

    K. L. Hohn; C.-C. Huang; C. Cao

    2009-01-01

    Catalytic ignition refers to phenomenon where sufficient energy is released from a catalytic reaction to maintain further reaction without additional extemai heating. This phenomenon is important in the development of catalytic combustion and catalytic partial oxidation processes, both of which have received extensive attention in recent years. In addition, catalytic ignition studies provide experimental data which can be used to test theoretical hydrocarbon oxidation models. For these reasons, catalytic ignition has been frequently studied. This review summarizes the experimental methods used to study catalytic ignition of light hydrocarbons and describes the experimental and theoretical results obtained related to catalytic ignition. The role of catalyst metal, fuel and fuel concentration, and catalyst state in catalytic ignition are examined, and some conclusions are drawn on the mechanism of catalytic ignition.

  10. (1)H, (13)C, (15)N backbone and side-chain resonance assignment of Nostoc sp. C139A variant of the heme-nitric oxide/oxygen binding (H-NOX) domain.

    Science.gov (United States)

    Alexandropoulos, Ioannis I; Argyriou, Aikaterini I; Marousis, Kostas D; Topouzis, Stavros; Papapetropoulos, Andreas; Spyroulias, Georgios A

    2016-10-01

    The H-NOX (Heme-nitric oxide/oxygen binding) domain is conserved across eukaryotes and bacteria. In human soluble guanylyl cyclase (sGC) the H-NOX domain functions as a sensor for the gaseous signaling agent nitric oxide (NO). sGC contains the heme-binding H-NOX domain at its N-terminus, which regulates the catalytic site contained within the C-terminal end of the enzyme catalyzing the conversion of GTP (guanosine 5'-triphosphate) to GMP (guanylyl monophosphate). Here, we present the backbone and side-chain assignments of the (1)H, (13)C and (15)N resonances of the 183-residue H-NOX domain from Nostoc sp. through solution NMR.

  11. NOx emission estimates during the 2014 Youth Olympic Games in Nanjing

    Science.gov (United States)

    Ding, J.; van der A, R. J.; Mijling, B.; Levelt, P. F.; Hao, N.

    2015-08-01

    The Nanjing Government applied temporary environmental regulations to guarantee good air quality during the Youth Olympic Games (YOG) in 2014. We study the effect of those regulations by applying the emission estimate algorithm DECSO (Daily Emission estimates Constrained by Satellite Observations) to measurements of the Ozone Monitoring Instrument (OMI). We improved DECSO by updating the chemical transport model CHIMERE from v2006 to v2013 and by adding an Observation minus Forecast (OmF) criterion to filter outlying satellite retrievals due to high aerosol concentrations. The comparison of model results with both ground and satellite observations indicates that CHIMERE v2013 is better performing than CHIMERE v2006. After filtering the satellite observations with high aerosol loads that were leading to large OmF values, unrealistic jumps in the emission estimates are removed. Despite the cloudy conditions during the YOG we could still see a decrease of tropospheric NO2 column concentrations of about 32 % in the OMI observations when compared to the average NO2 columns from 2005 to 2012. The results of the improved DECSO algorithm for NOx emissions show a reduction of at least 25 % during the YOG period and afterwards. This indicates that air quality regulations taken by the local government have an effect in reducing NOx emissions. The algorithm is also able to detect an emission reduction of 10 % during the Chinese Spring Festival. This study demonstrates the capacity of the DECSO algorithm to capture the change of NOx emissions on a monthly scale. We also show that the observed NO2 columns and the derived emissions show different patterns that provide complimentary information. For example, the Nanjing smog episode in December 2013 led to a strong increase in NO2 concentrations without an increase in NOx emissions. Furthermore, DECSO gives us important information on the non-trivial seasonal relation between NOx emissions and NO2 concentrations on a local scale.

  12. Experimental research on removing cyanide and ammonia nitrogen from industrial waste water produced by gold smelting with electro-catalytic oxidation process%电催化氧化法去除黄金冶炼废水中氰化物和氨氮试验研究

    Institute of Scientific and Technical Information of China (English)

    方荣茂; 廖小山; 廖斌; 林烽先; 刘亚建

    2013-01-01

    Research started with treating industrial waste water produced by gold smelting with electro-catalytic oxidation process, during which the influences of chloride ion mass concentration, plate clearance and current density on the removal of cyanide and ammonia nitrogen were analyzed. The result shows the optimal conditions for removing cyanide and ammonia nitrogen with electro-catalytic oxidation process are like this; the initial pH of waste water 9. 28, initial chloride ion concentration 25 g/L, plate clearance 20 mm, current density 16.3 mA/cm2 , and waste water circulation velocity 64 mL/min. With the above conditions and electrolysis time 150 min,the cyanide concentration decreases from 28. 84 mg/L to 0. 20 mg/L,and ammonia nitrogen from 700 mg/L to 7 mg/L. The removal rate is respectively 99. 3 % and 99. 0 %. The cyanide and ammonia nitrogen concentration remained in the treated water has reached of Grade 1 requirements of Integrated waste water discharge standard ( GB 8978 - 1996). The power consumption per ton water is 13.1 kw·h.%对黄金冶炼废水进行了电催化氧化处理研究,考察了氯离子质量浓度、极板间距、电流密度等因素对氰化物和氨氮去除效果的影响.最佳工艺参数为:废水初始pH值9.28、氯离子初始质量浓度25 g/L、极板间距20 mm、电流密度16.3 mA/cm2、废水循环流速64 mL/min.在最佳工艺条件下,电解150 min,氰化物质量浓度从28.84 mg/L降至0.20 mg/L,氨氮质量浓度从700 mg/L降至7 mg/L,去除率分别为99.3%、99.0%,处理后废水中的总氰、氨氮均可达到《GB 8978-1996污水综合排放标准》一级标准.

  13. NOx Prediction Based on Cylinder Pressure Measurement for Engine Emission Monitoring

    OpenAIRE

    Tesfa, Belachew; Mishra, Rakesh; Zhang, Cuiping; Gu, Fengshou; Ball, Andrew

    2011-01-01

    Meeting European NOx emission standards is one of the biggest challenges facing automotive industries. The available technologies to measure NOx emission are dependent on measurement of different NOx species. In addition, in most cases it requires conversion of other NOx species to NO for measurement purposes. The ability to measure NOx emission on-line during the transient engine operation may be very difficult due to the delay in reaction time in the NOx measuring apparatus. NOx emissions i...

  14. 催化燃烧治理氯苯类挥发性有机化合物的最新进展%Recent process in the removal of chlorobenzenes volatile organic compounds by catalytic combustion

    Institute of Scientific and Technical Information of China (English)

    于旭霞; 冯俊小

    2016-01-01

    氯苯类(CBs)化合物的排放给环境带来严重的污染和危害。本文回顾和总结了近几年来的氯苯类挥发性有机污染物的处理方法,综述了所采用催化剂的国内外研究现状,并对不同种方法进行优缺点分析。结果表明:催化燃烧法是最具有应用前景的、最有效的处理 CBs 的技术之一,该法优势是能够在催化剂存在的条件下,高效地处理低浓度的污染物,操作温度低,避免了氮氧化物的产生。应用于催化燃烧的催化剂类型繁多,贵金属催化剂具有高活性但对高温敏感;过渡金属氧化物催化剂的抗氯中毒能力较强;钙钛矿类催化剂廉价易得,其A、B位原子具有良好的可调性,并可通过负载与改性弥补其反应温度高及易失活等缺点。与其他催化剂相对比,钙钛矿类催化剂具有更广泛的应用前景。%Emission of chlorobenzenes (CBs) substance has caused serious pollutions to our environment. This paper reviewed the approaches of treating chlorobenzene volatile organic compounds in recent years,and also summarized the research status of catalysts as well as the advantages and disadvantages of different types of methods. The results showed that catalytic combustion treatment method was one of the most promising and effective treatment techniques for CBs,because the contaminants of low concentrations could be disposed effectively with the help of catalysts at low operating temperature with no nitrogen oxides generated during the process. Many types of catalysts can be applied to the catalytic combustion. While the noble metal catalysts have high activity but sensitive to temperature,and the transition metal oxide catalysts have strong ability to resist chlorine poisoning,the perovskite-based catalysts have wider applications. Perovskite-based catalysts are inexpensive and easy to obtain,and the A and B atoms in the molecular have a good adjustability. By means of

  15. Development of NOx recycle process for practical use at reprocessing plant

    International Nuclear Information System (INIS)

    To realize the NOx recycle process using the vacuum pressure swing adsorption method reported previously, development experiments were carried out. Among such experiments were the removal of volatile ruthenium tetroxide from the off-gas, 23-month operation of a bench-scale apparatus and 100-day operation of a pilot plant 1/5 the size of actual scale. After evaluation of the results for operability and durability of components under acidic conditions, this process was concluded applicable to an actual plant. Compared to the conventional NOx production method using chemical reaction, it has the great advantage of-reducing largely low-level radioactive and non-radioactive sodium nitrate waste. With this conclusion, the procedure to install the process at the Rokkasho Reprocessing Plant has been commenced. (author)

  16. Reducción catalítica selectiva de NOx usando nanopartículas de ferritas Cu1-XCoXFe2O4 como catalizador

    Directory of Open Access Journals (Sweden)

    Sarah Briceño1*

    2009-12-01

    Full Text Available Nanostructured catalysts AB2O4 spinel type oxides (A = Co and B = Cu were prepared by the sol-gel self-combustion method using citric acid as precursor. They were characterized by X-ray diffraction (XRD, Scanning Electron Microscopy (SEM, Transmission Electron Microscopy (TEM and Catalytic activity tests, which have proven to be effective for selective catalytic reduction of NOx using hydrocarbon as a reducing agent (SCR-HC in a temperature range 250 - 450 ° C, reaching up to 40% conversion of NO and 100% selectivity towards the formation of N2

  17. Electrochemical NOx reduction on an LSM/CGO symmetric cell modified by NOx adsorbents

    DEFF Research Database (Denmark)

    Shao, Jing; Kammer Hansen, Kent

    2013-01-01

    This study investigated the effect of modifying a (La0.85Sr0.15)0.99MnO3 (LSM)/Ce0.9Gd0.1O1.95 (CGO) symmetric cell by NOx adsorbents on the electrochemical reduction of NOx under O2-rich conditions. The modification was based on a full ceramic cell structure without any noble metals. Three cells...... were prepared and tested: a blank cell, a cell impregnated with BaO, and a cell coated with a BaO/Pt/Al2O3 layer. The electrochemical reduction of NOx on the three cells was studied by conversion measurement, degradation testing, and microstructure characterization. The modification, either...... to the impedance of the diffusion of NOx to the reaction sites by the adsorption layer. For lowering the operation temperature and minimizing the power consumption, adding an adsorption layer was shown to be the optimum approach for modifying the electrochemical cell by NOx adsorbents. The square wave (SV...

  18. Catalytic coherence transformations

    Science.gov (United States)

    Bu, Kaifeng; Singh, Uttam; Wu, Junde

    2016-04-01

    Catalytic coherence transformations allow the otherwise impossible state transformations using only incoherent operations with the aid of an auxiliary system with finite coherence that is not being consumed in any way. Here we find the necessary and sufficient conditions for the deterministic and stochastic catalytic coherence transformations between a pair of pure quantum states. In particular, we show that the simultaneous decrease of a family of Rényi entropies of the diagonal parts of the states under consideration is a necessary and sufficient condition for the deterministic catalytic coherence transformations. Similarly, for stochastic catalytic coherence transformations we find the necessary and sufficient conditions for achieving a higher optimal probability of conversion. We thus completely characterize the coherence transformations among pure quantum states under incoherent operations. We give numerous examples to elaborate our results. We also explore the possibility of the same system acting as a catalyst for itself and find that indeed self-catalysis is possible. Further, for the cases where no catalytic coherence transformation is possible we provide entanglement-assisted coherence transformations and find the necessary and sufficient conditions for such transformations.

  19. HPWA-SBA-15催化氧化吸附脱除汽油中的噻吩硫%Removal of thiophene sulfur from gasoline by HPWA-SBA-15 catalytic oxidation absorption

    Institute of Scientific and Technical Information of China (English)

    阮本玺; 沈健; 李少凯; 聂宁

    2013-01-01

    以纯硅介孔分子筛SBA-15为载体,磷钨酸为活性组分,采用直接合成法制备HPWA(磷钨酸)-SBA-15催化剂,并用XRD,BET法对负载磷钨酸后的SBA-15的结构进行分析.以过氧化氢特丁基为氧化剂,二苯并噻吩(DBT)的异辛烷溶液为模拟油进行实验,对介孔分子筛催化剂HPWA-SBA-15的氧化吸附脱硫性能进行研究.结果表明,负载磷钨酸以后,催化剂Nb-SBA-15仍具有规则的二维六方介孔结构,仍属于介孔分子材料;磷钨酸负载量为30%时脱硫效果最佳;Nb-SBA-15催化剂具有较高的催化活性和稳定性.在反应温度为70℃,反应时间为60 min,催化剂用量占总质量的2.2%时,脱硫率达到了100%.%The HPWA-SBA-15 catalyst has been prepared with silicon mesoporous molecular sieve SBA-15 as a carrier and phosphotungstic acid as active component by direct synthesis method. The structure of SBA-15 after support with phosphotungstic acid is analyzed by XRD and BET. With hydrogen peroxide butyl as catalyst and dibenzol thiophene ( DBT) isooctane solution as simulation oil, the oxidation desulfurization performance of mesoporous molecular sieve SBA-15 catalyst is studied in the experiment. The results of the experiment show that,after supporting with phosphotungstic acid,the catalyst Nb-SBA-15 still have regular two-dimensional hexagonal mesopporouse structure and still is the mesoporous molecular materials. When phosphotungstic acid support is up to 30% , the desulfurization efficiency is the highest. Nb-SBA-15 catalyst has a higher catalytic activity and stability. At the conditions of reaction time of 60 minutes and temperature of 70 ℃, the catalyst consumption is 2.2% of the total mass, and desulfurization rate is 100%.

  20. Production of activated carbons from waste tyres for low temperature NOx control.

    Science.gov (United States)

    Al-Rahbi, Amal S; Williams, Paul T

    2016-03-01

    Waste tyres were pyrolysed in a bench scale reactor and the product chars were chemically activated with alkali chemical agents, KOH, K2CO3, NaOH and Na2CO3 to produce waste tyre derived activated carbons. The activated carbon products were then examined in terms of their ability to adsorb NOx (NO) at low temperature (25°C) from a simulated industrial process flue gas. This study investigates the influence of surface area and porosity of the carbons produced with the different alkali chemical activating agents on NO capture from the simulated flue gas. The influence of varying the chemical activation conditions on the porous texture and corresponding NO removal from the flue gas was studied. The activated carbon sorbents were characterized in relation to BET surface area, micropore and mesopore volumes and chemical composition. The highest NO removal efficiency for the waste tyre derived activated carbons was ∼75% which was obtained with the adsorbent treated with KOH which correlated with both the highest BET surface area and largest micropore volume. In contrast, the waste tyre derived activated carbons prepared using K2CO3, NaOH and Na2CO3 alkali activating agents appeared to have little influence on NO removal from the flue gases. The results suggest problematic waste tyres, have the potential to be converted to activated carbons with NOx removal efficiency comparable with conventionally produced carbons. PMID:26856444