Science.gov

Sample records for nitrogen oxides combustion

  1. Combuster. [low nitrogen oxide formation

    NASA Technical Reports Server (NTRS)

    Mckay, R. A. (Inventor)

    1978-01-01

    A combuster is provided for utilizing a combustible mixture containing fuel and air, to heat a load fluid such as water or air, in a manner that minimizes the formation of nitrogen oxide. The combustible mixture passes through a small diameter tube where the mixture is heated to its combustion temperature, while the load fluid flows past the outside of the tube to receive heat. The tube is of a diameter small enough that the combustible mixture cannot form a flame, and yet is not subject to wall quench, so that combustion occurs, but at a temperature less than under free flame conditions. Most of the heat required for heating the combustible mixture to its combustion temperature, is obtained from heat flow through the walls of the pipe to the mixture.

  2. From combustion and detonation to nitrogen oxides

    NASA Astrophysics Data System (ADS)

    Ivanov, M. F.; Kiverin, A. D.; Klumov, B. A.; Fortov, V. E.

    2014-03-01

    This paper looks at Ya B Zeldovich's ideas on the combustion and detonation physics of gaseous mixtures and how they evolved as work in this field progressed. The paper demonstrates the fundamental role of Zeldovich's concept of spontaneous combustion waves in studying transient initiation processes for various combustion regimes and in determining the energy and concentration inflammation limits for combustible gaseous mixtures. It shows how his notion that flame front stretching crucially influences flame acceleration in channels explains in a new way the deflagration-to-detonation transition in highly reactive gaseous mixtures. Most of the presented results were obtained by simulations, allowing Zeldovich's ideas to be extended to the combustion of real gaseous mixtures, where chemical reactions and gasdynamical flows add hugely to the complexity of the problem. The paper concludes by using Zeldovich's mechanism to assess the amount of nitrogen oxide produced by a lightning discharge.

  3. NITROGEN OXIDE CONTROL FOR STATIONARY COMBUSTION SOURCES

    EPA Science Inventory

    Nitrogen dioxide is a criteria pollutant under the Clean Air Act and emissions of nitrogen oxides must be controlled to achieve attainment with the ambient standards. his handbook presents an overview of technologies that may be applicable to control the four major stationary sou...

  4. Method for removal of nitrogen oxides from stationary combustion sources

    NASA Technical Reports Server (NTRS)

    Cooper, Charles D. (Inventor); Clausen, III, Christian A. (Inventor); Collins, Michelle M. (Inventor)

    2004-01-01

    A method for removing NO.sub.X from gas streams emanating from stationary combustion sources and manufacturing plants utilizes the injection of hydrogen peroxide into the gas stream for rapid gas-phase oxidation of NO to NO.sub.2 and water-soluble nitrogen acids HNO.sub.2 and HNO.sub.3. The nitrogen acids may be removed from the oxidized gas stream by wet scrubbing or by contact with a particulate alkaline material to form a nitrite/nitrate salt.

  5. Method for reducing nitrogen oxides in combustion effluents

    DOEpatents

    Zauderer, Bert

    2000-01-01

    Method for reducing nitrogen oxides (NO.sub.x) in the gas stream from the combustion of fossil fuels is disclosed. In a narrow gas temperature zone, NO.sub.x is converted to nitrogen by reaction with urea or ammonia with negligible remaining ammonia and other reaction pollutants. Specially designed injectors are used to introduce air atomized water droplets containing dissolved urea or ammonia into the gaseous combustion products in a manner that widely disperses the droplets exclusively in the optimum reaction temperature zone. The injector operates in a manner that forms droplet of a size that results in their vaporization exclusively in this optimum NO.sub.x -urea/ammonia reaction temperature zone. Also disclosed is a design of a system to effectively accomplish this injection.

  6. 40 CFR 52.277 - Oxides of nitrogen, combustion gas concentration limitations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 3 2013-07-01 2013-07-01 false Oxides of nitrogen, combustion gas... Oxides of nitrogen, combustion gas concentration limitations. (a) The following rules are being retained... in effect for sources combusting liquid or solid fuels with heat input rates greater than...

  7. 40 CFR 52.277 - Oxides of nitrogen, combustion gas concentration limitations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 3 2011-07-01 2011-07-01 false Oxides of nitrogen, combustion gas... Oxides of nitrogen, combustion gas concentration limitations. (a) The following rules are being retained... in effect for sources combusting liquid or solid fuels with heat input rates greater than...

  8. 40 CFR 52.277 - Oxides of nitrogen, combustion gas concentration limitations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Oxides of nitrogen, combustion gas... Oxides of nitrogen, combustion gas concentration limitations. (a) The following rules are being retained... in effect for sources combusting liquid or solid fuels with heat input rates greater than...

  9. 40 CFR 52.277 - Oxides of nitrogen, combustion gas concentration limitations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 3 2012-07-01 2012-07-01 false Oxides of nitrogen, combustion gas... Oxides of nitrogen, combustion gas concentration limitations. (a) The following rules are being retained... in effect for sources combusting liquid or solid fuels with heat input rates greater than...

  10. 40 CFR 52.277 - Oxides of nitrogen, combustion gas concentration limitations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 3 2014-07-01 2014-07-01 false Oxides of nitrogen, combustion gas... Oxides of nitrogen, combustion gas concentration limitations. (a) The following rules are being retained... in effect for sources combusting liquid or solid fuels with heat input rates greater than...

  11. COMBUSTION MODIFICATION CONTROL OF NITROGEN OXIDES (EPA/600/F-95/012)

    EPA Science Inventory

    EPA's efforts in research and development of nitrogen oxide (NOx) control technologies by
    means of modifying the combustion process have played a major role in reducing stationary
    source NOx emissions by over 3 million tons (2.73 x 10^6 tonnes) annually, and have led to at<...

  12. Nitrogen Stable Isotope Composition of Various Fossil-fuel Combustion Nitrogen Oxide Sources

    NASA Astrophysics Data System (ADS)

    Walters, W.; Michalski, G. M.; Fang, H.

    2015-12-01

    Nitrogen oxides (NOx = NO + NO2) are important trace gases that impact atmospheric chemistry, air quality, and climate. In order to help constrain NOx source contributions, the nitrogen (N) stable isotope composition of NOx (δ15N-NOx) may be a useful indicator for NOx source partitioning. However, despite anthropogenic emissions being the most prevalent source of NOx, there is still large uncertainty in the δ15N-NOx values for anthropogenic sources. To this end, this study provides a detailed analysis of several fossil-fuel combustion NOx sources and their δ15N-NOx values. To accomplish this, exhaust or flue samples from several fossil-fuel combustion sources were sampled and analyzed for their δ15N-NOx that included airplanes, gasoline-powered vehicles not equipped with a catalytic converter, gasoline-powered lawn tools and utility vehicles, diesel-electric buses, diesel semi-trucks, and natural gas-burning home furnace and power plant. A relatively large range of δ15N-NOx values were measured from -28.1 to 0.3‰ for individual exhaust/flue samples with cold started diesel-electric buses contributing on average the lowest δ15N-NOx values at -20.9‰, and warm-started diesel-electric buses contributing on average the highest values of -1.7‰. The NOx sources analyzed in this study primarily originated from the "thermal production" of NOx and generally emitted negative δ15N-NOx values, likely due to the kinetic isotope effect associated with its production. It was found that there is a negative correlation between NOx concentrations and δ15N-NOx for fossil-fuel combustion sources equipped with catalytic NOx reduction technology, suggesting that the catalytic reduction of NOx may have an influence on δ15N-NOx values. Based on the δ15N-NOx values reported in this study and in previous studies, a δ15N-NOx regional and seasonal isoscape was constructed for the contiguous United States. The constructed isoscape demonstrates the seasonal importance of various

  13. 40 CFR Table 1 to Subpart Kkkk of... - Nitrogen Oxide Emission Limits for New Stationary Combustion Turbines

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Stationary Combustion Turbines 1 Table 1 to Subpart KKKK of Part 60 Protection of Environment ENVIRONMENTAL... Standards of Performance for Stationary Combustion Turbines Pt. 60, Subpt. KKKK, Table 1 Table 1 to Subpart KKKK of Part 60—Nitrogen Oxide Emission Limits for New Stationary Combustion Turbines...

  14. 40 CFR Table 1 to Subpart Kkkk of... - Nitrogen Oxide Emission Limits for New Stationary Combustion Turbines

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Stationary Combustion Turbines 1 Table 1 to Subpart KKKK of Part 60 Protection of Environment ENVIRONMENTAL... Standards of Performance for Stationary Combustion Turbines Pt. 60, Subpt. KKKK, Table 1 Table 1 to Subpart KKKK of Part 60—Nitrogen Oxide Emission Limits for New Stationary Combustion Turbines...

  15. 40 CFR Table 1 to Subpart Kkkk of... - Nitrogen Oxide Emission Limits for New Stationary Combustion Turbines

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Stationary Combustion Turbines 1 Table 1 to Subpart KKKK of Part 60 Protection of Environment ENVIRONMENTAL... Standards of Performance for Stationary Combustion Turbines Pt. 60, Subpt. KKKK, Table 1 Table 1 to Subpart KKKK of Part 60—Nitrogen Oxide Emission Limits for New Stationary Combustion Turbines...

  16. 40 CFR Table 1 to Subpart Kkkk of... - Nitrogen Oxide Emission Limits for New Stationary Combustion Turbines

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Stationary Combustion Turbines 1 Table 1 to Subpart KKKK of Part 60 Protection of Environment ENVIRONMENTAL... Standards of Performance for Stationary Combustion Turbines Pt. 60, Subpt. KKKK, Table 1 Table 1 to Subpart KKKK of Part 60—Nitrogen Oxide Emission Limits for New Stationary Combustion Turbines...

  17. 40 CFR Table 1 to Subpart Kkkk of... - Nitrogen Oxide Emission Limits for New Stationary Combustion Turbines

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Stationary Combustion Turbines 1 Table 1 to Subpart KKKK of Part 60 Protection of Environment ENVIRONMENTAL... Standards of Performance for Stationary Combustion Turbines Pt. 60, Subpt. KKKK, Table 1 Table 1 to Subpart KKKK of Part 60—Nitrogen Oxide Emission Limits for New Stationary Combustion Turbines...

  18. An analytical study of nitrogen oxides and carbon monoxide emissions in hydrocarbon combustion with added nitrogen, preliminary results

    NASA Technical Reports Server (NTRS)

    Bittker, D. A.

    1979-01-01

    The effect of combustor operating conditions on the conversion of fuel-bound nitrogen (FBN) to nitrogen oxides NO sub x was analytically determined. The effect of FBN and of operating conditions on carbon monoxide (CO) formation was also studied. For these computations, the combustor was assumed to be a two stage, adiabatic, perfectly-stirred reactor. Propane-air was used as the combustible mixture and fuel-bound nitrogen was simulated by adding nitrogen atoms to the mixture. The oxidation of propane and formation of NO sub x and CO were modeled by a fifty-seven reaction chemical mechanism. The results for NO sub x and CO formation are given as functions of primary and secondary stage equivalence ratios and residence times.

  19. Simultaneous removal of nitrogen oxides and sulfur oxides from combustion gases

    DOEpatents

    Clay, David T.; Lynn, Scott

    1976-10-19

    A process for the simultaneous removal of sulfur oxides and nitrogen oxides from power plant stack gases comprising contacting the stack gases with a supported iron oxide catalyst/absorbent in the presence of sufficient reducing agent selected from the group consisting of carbon monoxide, hydrogen, and mixtures thereof, to provide a net reducing atmosphere in the SO.sub.x /NO.sub.x removal zone. The sulfur oxides are removed by absorption substantially as iron sulfide, and nitrogen oxides are removed by catalytic reduction to nitrogen and ammonia. The spent iron oxide catalyst/absorbent is regenerated by oxidation and is recycled to the contacting zone. Sulfur dioxide is also produced during regeneration and can be utilized in the production of sulfuric acid and/or sulfur.

  20. Nitrogen release during coal combustion

    SciTech Connect

    Baxter, L.L.; Mitchell, R.E.; Fletcher, T.H.; Hurt, R.H.

    1995-02-01

    Experiments in entrained flow reactors at combustion temperatures are performed to resolve the rank dependence of nitrogen release on an elemental basis for a suite of 15 U.S. coals ranging from lignite to low-volatile bituminous. Data were obtained as a function of particle conversion, with overall mass loss up to 99% on a dry, ash-free basis. Nitrogen release rates are presented relative to both carbon loss and overall mass loss. During devolatilization, fractional nitrogen release from low-rank coals is much slower than fractional mass release and noticeably slower than fractional carbon release. As coal rank increases, fractional nitrogen release rate relative to that of carbon and mass increases, with fractional nitrogen release rates exceeding fractional mass and fractional carbon release rates during devolatilization for high-rank (low-volatile bituminous) coals. At the onset of combustion, nitrogen release rates increase significantly. For all coals investigated, cumulative fractional nitrogen loss rates relative to those of mass and carbon passes through a maximum during the earliest stages of oxidation. The mechanism for generating this maximum is postulated to involve nascent thermal rupture of nitrogen-containing compounds and possible preferential oxidation of nitrogen sites. During later stages of oxidation, the cumulative fractional loss of nitrogen approaches that of carbon for all coals. Changes in the relative release rates of nitrogen compared to those of both overall mass and carbon during all stages of combustion are attributed to a combination of the chemical structure of coals, temperature histories during combustion, and char chemistry.

  1. Advanced modeling of nitrogen oxide emissions in circulating fluidized bed combustors: Parametric study of coal combustion and nitrogen compound chemistries

    SciTech Connect

    Kilpinen, P.; Kallio, S.; Hupa, M.

    1999-07-01

    This paper describes work-in-progress aimed at developing an emission model for circulating fluidized bed combustors using detailed homogeneous and heterogeneous chemical kinetics. The main emphasis is on nitrogen oxides (NO{sub x}, N{sub 2}O) but also unburned gases (CO, C{sub x}H{sub y}) and sulfur dioxide (SO{sub 2}) will be investigated in the long run. The hydrodynamics is described by a 1.5-dimensional model where the riser is divided into three regions: a dense bubbling bed at the bottom, a vigorously mixed splash zone, and a transport zone. The two latter zones are horizontally split into a core region and an annular region. The solids circulation rate is calculated from the known solids inventory and the pressure and mass balances over the entire circulation loop. The solids are divided into classes according to size and type or particle. The model assumes instantaneous fuel devolatilization at the bottom and an even distribution of volatiles in the suspension phase of the dense bed. For addition of secondary air, a complete penetration and an instantaneous mixing with the combustor gases in the core region is assumed. The temperature distribution is assumed to be known, and no energy balance is solved. A comprehensive kinetic scheme of about 300 elementary gas-phase reactions is used to describe the homogeneous oxidation of the volatiles including both hydrocarbon and volatile-nitrogen components (NH{sub 3}, HCN). Heterogeneous char combustion to CO and CO{sub 2}, and char-nitrogen conversion to NO, N{sub 2}O, and N{sub 2} are described by a single particle model that includes 15 reaction steps given in the form of 6 net reaction paths. In the paper, the model is briefly described. A special emphasis is put on the evaluation of chemistry submodels. Modeling results on nitrogen oxides' formation are compared with measured concentration profiles in a 12 MW CFBC riser from literature. The importance of accurate chemistry description on predictions is

  2. Material and system for catalytic reduction of nitrogen oxide in an exhaust stream of a combustion process

    DOEpatents

    Gardner, Timothy J.; Lott, Stephen E.; Lockwood, Steven J.; McLaughlin, Linda I.

    1998-01-01

    A catalytic material of activated hydrous metal oxide doped with platinum, palladium, or a combination of these, and optionally containing an alkali or alkaline earth metal, that is effective for NO.sub.X reduction in an oxidizing exhaust stream from a combustion process is disclosed. A device for reduction of nitrogen oxides in an exhaust stream, particularly an automotive exhaust stream, the device having a substrate coated with the activated noble-metal doped hydrous metal oxide of the invention is also provided.

  3. Method and system for the removal of oxides of nitrogen and sulfur from combustion processes

    DOEpatents

    Walsh, John V.

    1987-12-15

    A process for removing oxide contaminants from combustion gas, and employing a solid electrolyte reactor, includes: (a) flowing the combustion gas into a zone containing a solid electrolyte and applying a voltage and at elevated temperature to thereby separate oxygen via the solid electrolyte, (b) removing oxygen from that zone in a first stream and removing hot effluent gas from that zone in a second stream, the effluent gas containing contaminant, (c) and pre-heating the combustion gas flowing to that zone by passing it in heat exchange relation with the hot effluent gas.

  4. 40 CFR Table 3 to Subpart Jjj of... - Class I Nitrogen Oxides Emission Limits for Existing Small Municipal Waste Combustion Unitsa,b,c

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 8 2011-07-01 2011-07-01 false Class I Nitrogen Oxides Emission Limits for Existing Small Municipal Waste Combustion Unitsa,b,c 3 Table 3 to Subpart JJJ of Part 62... 3 to Subpart JJJ of Part 62—Class I Nitrogen Oxides Emission Limits for Existing Small...

  5. 40 CFR Table 3 to Subpart Jjj of... - Class I Nitrogen Oxides Emission Limits for Existing Small Municipal Waste Combustion Unitsa,b,c

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 8 2010-07-01 2010-07-01 false Class I Nitrogen Oxides Emission Limits for Existing Small Municipal Waste Combustion Unitsa,b,c 3 Table 3 to Subpart JJJ of Part 62... 3 to Subpart JJJ of Part 62—Class I Nitrogen Oxides Emission Limits for Existing Small...

  6. 40 CFR Table 3 to Subpart Jjj of... - Class I Nitrogen Oxides Emission Limits for Existing Small Municipal Waste Combustion Units a b c

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 9 2014-07-01 2014-07-01 false Class I Nitrogen Oxides Emission Limits for Existing Small Municipal Waste Combustion Units a b c 3 Table 3 to Subpart JJJ of Part 62... 3 to Subpart JJJ of Part 62—Class I Nitrogen Oxides Emission Limits for Existing Small...

  7. 40 CFR Table 3 to Subpart Jjj of... - Class I Nitrogen Oxides Emission Limits for Existing Small Municipal Waste Combustion Unitsa,b,c

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 9 2012-07-01 2012-07-01 false Class I Nitrogen Oxides Emission Limits for Existing Small Municipal Waste Combustion Unitsa,b,c 3 Table 3 to Subpart JJJ of Part 62... 3 to Subpart JJJ of Part 62—Class I Nitrogen Oxides Emission Limits for Existing Small...

  8. 40 CFR Table 3 to Subpart Jjj of... - Class I Nitrogen Oxides Emission Limits for Existing Small Municipal Waste Combustion Unitsa,b,c

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 9 2013-07-01 2013-07-01 false Class I Nitrogen Oxides Emission Limits for Existing Small Municipal Waste Combustion Unitsa,b,c 3 Table 3 to Subpart JJJ of Part 62... 3 to Subpart JJJ of Part 62—Class I Nitrogen Oxides Emission Limits for Existing Small...

  9. Importance of solid fuel properties to nitrogen oxide formation through HCN and NH[sub 3] in small particle combustion

    SciTech Connect

    Aho, M.J.; Haemaelaeinen, J.P.; Tummavuori, J.L. Univ. of Jyvaeskylae . Dept. of Chemistry)

    1993-10-01

    The formation of nitrogen oxides from fuel-nitrogen through intermediates was studied by measuring first fuel-O/fuel-N ratios and nitrogen functionality in selected solid fuels. Then the ratios of the yields (fuel-N [r arrow] HCN)/(fuel-N [r arrow] NH[sub 3]) in a nearly inert atmosphere at 800 C in an entrained flow reactor was measured and finally the ratio (fuel-N [r arrow] N[sub 2]O)/(fuel-N [r arrow] NO) in an oxidizing atmosphere at 800 C The fuels studied were coal, brown coal, S- and C-type peat, fir bark, birch bark and pine bark, all milled to a particle size < 63[mu]m. The ratios of O/N in the fuel, measured by elemental analysis, ranged from 7 to 150. Nitrogen functionality (mass percent of the total nitrogen content) was determined by XPS. the (fuel-N [r arrow] HCN)/(fuel-N [r arrow] NH[sub 3]) conversion ratio in the absence of O[sub 2], and also the (fuel-N [r arrow] N[sub 2]O)/(fuel-N [r arrow] NO) conversion ratio with O[sub 2] present, decreased with increasing ratio of fuel-O/fuel-N, but neither ratio decreased regularly with the increasing ratio of pyrrolic to pyridinic nitrogen in the fuel. Thus, fuel-oxygen plays a more important role than nitrogen functionality in the chemistry of nitrogen oxide formation. The strong effect of (fuel-O/fuel-N) ratio on the (fuel-N [r arrow] HCN)/(fuel-N [r arrow] NH[sub 3]) ratio may be due to the reaction between OH radicals and HCN to form NH[sub 3] near the fuel particle. The importance of this reaction is considered. Charring the fuel sample before combustion led to a sharp drop in the conversion of fuel-N to N[sub 2]O compared with the virgin fuels. Thus, heterogeneous combustion reactions produced much less N[sub 2]O than homogeneous combustion reactions.

  10. Pathways for conversion of char nitrogen to nitric oxide during pulverized coal combustion

    SciTech Connect

    Molina, A.; Murphy, J.J.; Blevins, L.G.; Shaddix, C.R.; Winter, F.; Haynes, B.S.

    2009-03-15

    The conversion of nitrogen in char (char-N) to NO was studied both experimentally and computationally. In the experiments, pulverized coal char was produced from a U.S. high-volatile bituminous coal and burned in a dilute suspension at 1170 K, 1370 K and 1570 K, at an excess oxygen concentration of 8% (dry), with different levels of background NO. In some experiments, hydrogen bromide (HBr) was added to the vitiated air as a tool to alter the concentration of gas-phase radicals. During char combustion, low NO concentration and high temperature promoted the conversion of char-N to NO. HBr addition altered NO production in a way that depended on temperature. At 1170 K the presence of HBr increased NO production by 80%, whereas the addition of HBr decreased NO production at higher temperatures by 20%. To explain these results, three mechanistic descriptions of char-N evolution during combustion were evaluated with computational models that simulated (a) homogeneous chemistry in a plug-flow reactor with entrained particle combustion, and (b) homogeneous chemistry in the boundary layer surrounding a reacting particle. The observed effect of HBr on NO production could only be captured by a chemical mechanism that considered significant release of HCN from the char particle. Release of HCN also explained changes in NO production with temperature and NO concentration. Thus, the combination of experiments and simulations suggests that HCN evolution from the char during pulverized coal combustion plays an essential role in net NO production. (author)

  11. Removal of oxides of nitrogen from gases in multi-stage coal combustion

    DOEpatents

    Mollot, Darren J.; Bonk, Donald L.; Dowdy, Thomas E.

    1998-01-01

    Polluting NO.sub.x gas values are removed from off-gas of a multi-stage coal combustion process which includes an initial carbonizing reaction, firing of char from this reaction in a fluidized bed reactor, and burning of gases from the carbonizing and fluidized bed reactions in a topping combustor having a first, fuel-rich zone and a second, fuel-lean zone. The improvement by means of which NO.sub.x gases are removed is directed to introducing NO.sub.x -free oxidizing gas such as compressor air into the second, fuel-lean zone and completing combustion with this source of oxidizing gas. Excess air fed to the fluidized bed reactor is also controlled to obtain desired stoichiometry in the first, fuel-rich zone of the topping combustor.

  12. Removal of oxides of nitrogen from gases in multi-stage coal combustion

    DOEpatents

    Mollot, D.J.; Bonk, D.L.; Dowdy, T.E.

    1998-01-13

    Polluting NO{sub x} gas values are removed from off-gas of a multi-stage coal combustion process which includes an initial carbonizing reaction, firing of char from this reaction in a fluidized bed reactor, and burning of gases from the carbonizing and fluidized bed reactions in a topping combustor having a first, fuel-rich zone and a second, fuel-lean zone. The improvement by means of which NO{sub x} gases are removed is directed to introducing NO{sub x}-free oxidizing gas such as compressor air into the second, fuel-lean zone and completing combustion with this source of oxidizing gas. Excess air fed to the fluidized bed reactor is also controlled to obtain desired stoichiometry in the first, fuel-rich zone of the topping combustor. 2 figs.

  13. An analytical study of nitrogen oxides and carbon monoxide emissions in hydrocarbon combustion with added nitrogen - Preliminary results

    NASA Technical Reports Server (NTRS)

    Bittker, D. A.

    1980-01-01

    The influence of ground-based gas turbine combustor operating conditions and fuel-bound nitrogen (FBN) found in coal-derived liquid fuels on the formation of nitrogen oxides and carbon monoxide is investigated. Analytical predictions of NOx and CO concentrations are obtained for a two-stage, adiabatic, perfectly-stirred reactor operating on a propane-air mixture, with primary equivalence ratios from 0.5 to 1.7, secondary equivalence ratios of 0.5 or 0.7, primary stage residence times from 12 to 20 msec, secondary stage residence times of 1, 2 and 3 msec and fuel nitrogen contents of 0.5, 1.0 and 2.0 wt %. Minimum nitrogen oxide but maximum carbon monoxide formation is obtained at primary zone equivalence ratios between 1.4 and 1.5, with percentage conversion of FBN to NOx decreasing with increased fuel nitrogen content. Additional secondary dilution is observed to reduce final pollutant concentrations, with NOx concentration independent of secondary residence time and CO decreasing with secondary residence time; primary zone residence time is not observed to affect final NOx and CO concentrations significantly. Finally, comparison of computed results with experimental values shows a good semiquantitative agreement.

  14. Oxides of Nitrogen Emissions from the Combustion of Monodisperse Liquid Fuel Sprays. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Sarv, H.

    1985-01-01

    A study of NO sub x formation in a one dimensional monodisperse spray combustion system, which allowed independent droplet size variation, was conducted. Temperature, NO and NO sub x concentrations were measured in the transition region, encompassing a 26 to 74 micron droplet size range. Emission measurements of hydrocarbons, carbon monoxide, carbon dioxide and oxygen were also made. The equivalence ratio was varied between 0.8 and 1.2 for the fuels used, including methanol, isopropanaol, n-heptane and n-octane. Pyridine and pyrrole were added to n-heptane as nitrogen-containing additives in order to simulate synthetic fuels. Results obtained from the postflame regions using the pure fuels indicate an optimum droplet size in the range of 43 to 58 microns for minimizing NO sub x production. For the fuels examined, the maximum NO sub x reductions relative to the small droplet size limit were about 10 to 20% for lean and 20 to 30% for stoichiometric and rich mixtures. This behavior is attributed to droplet interactions and the transition from diffusive to premixed type of burning. Preflame vaporization controls the gas phase stoichiometry which has a significant effect on the volume of the hot gases surrounding a fuel droplet, where NO sub x is formed.

  15. 40 CFR Table 3 to Subpart Bbbb of... - Model Rule-Class I Nitrogen Oxides Emission Limits for Existing Small Municipal Waste Combustion...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Model Rule-Class I Nitrogen Oxides Emission Limits for Existing Small Municipal Waste Combustion Unitsa,b,c 3 Table 3 to Subpart BBBB of Part 60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW...

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

    DOEpatents

    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.

  17. Lean premixed recirculating flow combustion for control of oxides of nitrogen

    NASA Technical Reports Server (NTRS)

    Schefer, R. W.; Sawyer, R. F.

    1977-01-01

    The objectives of the reported investigation included the demonstration of a system in which combustion can be maintained under very lean conditions. Aspects of pollutant formation and the stability characteristics of the system were studied. An opposed reacting jet model laboratory combustor was employed in the experiments. Results obtained with the aid of an analytical modeling technique based on the computational scheme reported by Gosman et al. (1969) are also presented. The investigation indicates that fuel lean combustion might provide an effective means of achieving low pollutant emission levels.

  18. Decomposition of nitric oxide in a hot nitrogen stream to synthesize air for hypersonic wind tunnel combustion testing

    NASA Technical Reports Server (NTRS)

    Zumdieck, J. F.; Zlatarich, S. A.

    1974-01-01

    A clean source of high enthalpy air was obtained from the exothermic decomposition of nitric oxide in the presence of strongly heated nitrogen. A nitric oxide jet was introduced into a confined coaxial nitrogen stream. Measurements were made of the extent of mixing and reaction. Experimental results are compared with one- and two-dimensional chemical kinetics computations. Both analyses predict much lower reactivity than was observed experimentally. Inlet nitrogen temperatures above 2400 K were sufficient to produce experimentally a completely reacted gas stream of synthetic air.

  19. Formation of oxides of nitrogen in monodisperse spray combustion of hydrocarbon fuels

    NASA Technical Reports Server (NTRS)

    Nizami, A. A.; Singh, S.; Cernansky, N. P.

    1982-01-01

    Experimental results of exit plane NO/NO(x) emissions from atmospheric monodisperse fuel spray combustion are presented. Six different hydrocarbon fuels were studied: isopropanol, n-propanol, n-octane, iso-octane, n-heptane and methanol. The results indicate an optimum droplet size for minimizing NO/NO(x) production for all of the test fuels. At the optimum droplet diameter, reductions in NO/NO(x) relative to the NO(x) occurred at droplet diameters of 55 and 48 microns respectively, as compared to a 50-micron droplet size for isopropanol. The occurrence of the minimum NO(x) point at different droplet diameters for the different fuels appears to be governed by the extent of prevaporization of the fuel in the spray, and is consistent with theoretical calculations based on each fuel's physical properties. Estimates are also given for the behavior of heavy fuels and of polydisperse fuel sprays in shifting the minimum NO(x) point compared to a monodisperse situation.

  20. Acid Rain Demonstration: The Formation of Nitrogen Oxides as a By-Product of High-Temperature Flames in Connection with Internal Combustion Engines

    NASA Astrophysics Data System (ADS)

    Driscoll, Jerry A.

    1997-12-01

    This demonstration illustrates the formation of nitrogen oxides resulting from a high temperature flame. The procedure is to burn hydrogen from a delivery tube in a 6 liter erlenmeyer flask filled with oxygen. (see original paper for safety precautions.) As the burning proceeds the water from the combustion condenses on the wall of the flask and eventually drips from the mouth of the flask. Air displaces the oxygen consumed. The nitrogen from the air reacts with the oxygen in the presence of the high temperature flame in the flask forming colorless nitric oxide which reacts further to form visible brown nitrogen dioxide in the flask. After the burn water can be introduced into the flask , capped, and shaken. An acid mist forms which slowly dissolves. An acid-base indicator will show that the solution is acid at about a pH 1-2 from nitrous and nitric acid. Nitrogen oxides do not form until the temperature is at least 1300 °C. The hydrogen flame in this demonstration is in the neighborhood of 3000 °C. Editor's Note: Please read Charles Braun's letter regarding the safety issues of the demonstration (JCE 1999, 76, 757).

  1. 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide emissions from coal-fired boilers

    SciTech Connect

    Sorge, J.N.; Menzies, B.; Smouse, S.M.; Stallings, J.W.

    1995-09-01

    Technology project demonstrating advanced wall-fired combustion techniques for the reduction of nitrogen oxide NOx emissions from coal-fired boilers. The primary objective of the demonstration is to determine the long-term NOx reduction performance of advanced overfire air (AOFA), low NOx burners (LNB), and advanced digital control/optimization methodologies applied in a stepwise fashion to a 500 MW boiler. The focus of this paper is to report (1) on the installation of three on-line carbon-in-ash monitors and (2) the design and results to date from the advanced digital control/optimization phase of the project.

  2. Nitrogen enriched combustion of a natural gas internal combustion engine to reduce NO.sub.x emissions

    DOEpatents

    Biruduganti, Munidhar S.; Gupta, Sreenath Borra; Sekar, R. Raj; McConnell, Steven S.

    2008-11-25

    A method and system for reducing nitrous oxide emissions from an internal combustion engine. An input gas stream of natural gas includes a nitrogen gas enrichment which reduces nitrous oxide emissions. In addition ignition timing for gas combustion is advanced to improve FCE while maintaining lower nitrous oxide emissions.

  3. Electro-catalytic reduction of nitrogen oxides

    SciTech Connect

    McLarnon, C.R.

    1989-12-01

    Nitrogen oxides have been linked to a broad range of air pollution problems including acid rain and the atmospheric production of photochemical ozone. Over twenty million tons of nitrogen oxides are emitted into the atmosphere each year as a result of the high temperature combustion of fossil fuels. Efforts to control nitrogen oxides emissions have lagged because of the generally low discharge concentrations of nitrogen oxides in combustion exhaust and because nitrogen oxides are more difficult to remove due to their lower reactivity. No catalyst has yet been found that will achieve significant reduction of nitrogen oxides in an oxidizing environment. Oxygen in the exhaust stream competes with nitrogen oxides for the active catalyst sites. Also, the dissociated oxygen atoms produced by decomposition of nitrogen oxides deactivate the surface of the catalyst. Externally applied electric fields have been used to control oxygen adsorption on metal and semi-conductor surfaces. In this investigation, a stream containing nitric oxide has been subjected to intense electric fields in the presence of catalyst materials including steel, stainless steel, and gold plated stainless steel wools and glass wool. The electric fields have been generated using DC, AC and rectified AC potentials in the range of 0--20 KV. The effect of parameters such as inlet nitric oxide concentration, oxygen and water content, gas residence time and temperature have also been studied.

  4. Development of Nanofiller-Modulated Polymeric Oxygen Enrichment Membranes for Reduction of Nitrogen Oxides in Coal Combustion

    SciTech Connect

    Jianzhong Lou; Shamsuddin Ilias

    2010-12-31

    North Carolina A&T State University in Greensboro, North Carolina, has undertaken this project to develop the knowledge and the material to improve the oxygen-enrichment polymer membrane, in order to provide high-grade oxygen-enriched streams for coal combustion and gasification applications. Both experimental and theoretical approaches were used in this project. The membranes evaluated thus far include single-walled carbon nano-tube, nano-fumed silica polydimethylsiloxane (PDMS), and zeolite-modulated polyimide membranes. To document the nanofiller-modulated polymer, molecular dynamics simulations have been conducted to calculate the theoretical oxygen molecular diffusion coefficient and nitrogen molecular coefficient inside single-walled carbon nano-tube PDMS membranes, in order to predict the effect of the nano-tubes on the gas-separation permeability. The team has performed permeation and diffusion experiments using polymers with nano-silica particles, nano-tubes, and zeolites as fillers; studied the influence of nano-fillers on the self diffusion, free volume, glass transition, oxygen diffusion and solubility, and perm-selectivity of oxygen in polymer membranes; developed molecular models of single-walled carbon nano-tube and nano-fumed silica PDMS membranes, and zeolites-modulated polyimide membranes. This project partially supported three graduate students (two finished degrees and one transferred to other institution). This project has resulted in two journal publications and additional publications will be prepared in the near future.

  5. 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide emissions from coal-fired boilers

    SciTech Connect

    Sorge, J.N.; Larrimore, C.L.; Slatsky, M.D.; Menzies, W.R.; Smouse, S.M.; Stallings, J.W.

    1997-12-31

    This paper discusses the technical progress of a US Department of Energy Innovative Clean Coal Technology project demonstrating advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NOx) emissions from coal-fired boilers. The primary objectives of the demonstration is to determine the long-term NOx reduction performance of advanced overfire air (AOFA), low NOx burners (LNB), and advanced digital control optimization methodologies applied in a stepwise fashion to a 500 MW boiler. The focus of this paper is to report (1) on the installation of three on-line carbon-in-ash monitors and (2) the design and results to date from the advanced digital control/optimization phase of the project.

  6. 40 CFR Table 3 to Subpart Bbbb of... - Model Rule-Class I Nitrogen Oxides Emission Limits for Existing Small Municipal Waste Combustion...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Model Rule-Class I Nitrogen Oxides... 3 to Subpart BBBB of Part 60—Model Rule—Class I Nitrogen Oxides Emission Limits for Existing Small... greater than 250 tons per day of municipal solid waste. See § 60.1940 for definitions. b Nitrogen...

  7. 40 CFR Table 3 to Subpart Bbbb of... - Model Rule-Class I Nitrogen Oxides Emission Limits for Existing Small Municipal Waste Combustion...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Model Rule-Class I Nitrogen Oxides... 3 to Subpart BBBB of Part 60—Model Rule—Class I Nitrogen Oxides Emission Limits for Existing Small... greater than 250 tons per day of municipal solid waste. See § 60.1940 for definitions. b Nitrogen...

  8. 40 CFR Table 3 to Subpart Bbbb of... - Model Rule-Class I Nitrogen Oxides Emission Limits for Existing Small Municipal Waste Combustion...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Model Rule-Class I Nitrogen Oxides... 3 to Subpart BBBB of Part 60—Model Rule—Class I Nitrogen Oxides Emission Limits for Existing Small... greater than 250 tons per day of municipal solid waste. See § 60.1940 for definitions. b Nitrogen...

  9. 40 CFR Table 3 to Subpart Bbbb of... - Model Rule-Class I Nitrogen Oxides Emission Limits for Existing Small Municipal Waste Combustion...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Model Rule-Class I Nitrogen Oxides... 3 to Subpart BBBB of Part 60—Model Rule—Class I Nitrogen Oxides Emission Limits for Existing Small... greater than 250 tons per day of municipal solid waste. See § 60.1940 for definitions. b Nitrogen...

  10. Nitrogen oxides, sulfur trioxide, and mercury emissions during oxy-fuel fluidized bed combustion of Victorian brown coal.

    PubMed

    Roy, Bithi; Chen, Luguang; Bhattacharya, Sankar

    2014-12-16

    This study investigates, for the first time, the NOx, N2O, SO3, and Hg emissions from combustion of a Victorian brown coal in a 10 kWth fluidized bed unit under oxy-fuel combustion conditions. Compared to air combustion, lower NOx emissions and higher N2O formation were observed in the oxy-fuel atmosphere. These NOx reduction and N2O formations were further enhanced with steam in the combustion environment. The NOx concentration level in the flue gas was within the permissible limit in coal-fired power plants in Victoria. Therefore, an additional NOx removal system will not be required using this coal. In contrast, both SO3 and gaseous mercury concentrations were considerably higher under oxy-fuel combustion compared to that in the air combustion. Around 83% of total gaseous mercury released was Hg(0), with the rest emitted as Hg(2+). Therefore, to control harmful Hg(0), a mercury removal system may need to be considered to avoid corrosion in the boiler and CO2 separation units during the oxy-fuel fluidized-bed combustion using this coal. PMID:25402169

  11. FATE OF COAL NITROGEN DURING COMBUSTION

    EPA Science Inventory

    The paper describes the burning of 21 coals, covering all ranks and under a wide variety of conditions, to ascertain the impact of coal properties on the fate of fuel nitrogen. Fuel NC was identified by using a nitrogen-free oxidant consisting of Ar/O2/CO2. It was found that fuel...

  12. 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. Technical progress report, second quarter 1994, April 1994--June 1994

    SciTech Connect

    1995-09-01

    This quarterly report discusses the technical progress of an Innovative Clean Coal Technology (ICCT) demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NOx) emissions from coal-fired boilers. The project is being conducted at Georgia Power Company`s Plant Hammond Unit 4 located near Rome, Georgia. The primary goal of this project is the characterization of the low NOx combustion equipment through the collection and analysis of long-term emissions data. A target of achieving fifty percent NOx reduction using combustion modifications has been established for the project. The project provides a stepwise retrofit of an advanced overfire air (AOFA) system followed by low NOx burners (LNB). During each test phase of the project, diagnostic, performance, long-term, and verification testing will be performed. These tests are used to quantify the NOx reductions of each technology and evaluate the effects of those reductions on other combustion parameters. Results are described.

  13. Modeling study of impact of water on carbon monoxide, PAH and nitrogen oxide emissions from combustion of surrogate fuel

    NASA Astrophysics Data System (ADS)

    Elsinawi, Abdulaziz H.

    Methods for reducing emissions are required to meet the new and increasingly stringent emission regulations for diesel engines. Water-emulsified fuel is one of the few promising emission reduction techniques with the potential to simultaneously reduce NOX and soot in diesel engines. Even though a better understanding could be obtained by modeling the processes involved, little effort has been directed toward modeling the combustion of water-in-fuel emulsion. This dissertation provides a better understanding of the effects of the presence of water in fuel in the form of emulsion on spray combustion and pollutant emissions, namely NOX, soot, and carbon monoxide by modeling the relevant processes and focusing on the variables behind the emission reduction and performance. The modeling study was performed using the commercially available software package CFD-ACE+ to simulate spray combustion at conditions relevant to diesel engines. Surrogate fuel (80% n-heptane and 20% toluene) was used instead of the conventional diesel fuel because the detailed kinetic and thermodynamic data needed for modeling is available for this surrogate fuel but not available for diesel. An emulsified fuel with 3, 5, 8 and 15% water by volume was used as an engine feed for each separate run and the results are compared with that of the dry surrogate fuel with 0% water. The modeling results are also validated against experimental data for 2-stroke diesel engines available in the literature [1]. The modeling results show that water had a significant effect on reducing engine operating temperature, NOX and the formation of soot precursors. However, the reduction of NOX and soot formation is at the expense of an increase in carbon monoxide (CO) emissions and elongated ignition delay time, which is disadvantageous for the steady running of diesel engines.

  14. Analysis of alternative pathways for reducing nitrogen oxide emissions

    EPA Science Inventory

    Strategies for reducing tropospheric ozone typically include modifying combustion processes to reduce the formation of nitrogen oxides (NOx) and applying control devices that remove NOx from the exhaust gases of power plants, industrial sources and vehicles. For portions of the ...

  15. Simplified Two-Time Step Method for Calculating Combustion Rates and Nitrogen Oxide Emissions for Hydrogen/Air and Hydorgen/Oxygen

    NASA Technical Reports Server (NTRS)

    Molnar, Melissa; Marek, C. John

    2005-01-01

    A simplified single rate expression for hydrogen combustion and nitrogen oxide production was developed. Detailed kinetics are predicted for the chemical kinetic times using the complete chemical mechanism over the entire operating space. These times are then correlated to the reactor conditions using an exponential fit. Simple first order reaction expressions are then used to find the conversion in the reactor. The method uses a two-time step kinetic scheme. The first time averaged step is used at the initial times with smaller water concentrations. This gives the average chemical kinetic time as a function of initial overall fuel air ratio, temperature, and pressure. The second instantaneous step is used at higher water concentrations (> 1 x 10(exp -20) moles/cc) in the mixture which gives the chemical kinetic time as a function of the instantaneous fuel and water mole concentrations, pressure and temperature (T4). The simple correlations are then compared to the turbulent mixing times to determine the limiting properties of the reaction. The NASA Glenn GLSENS kinetics code calculates the reaction rates and rate constants for each species in a kinetic scheme for finite kinetic rates. These reaction rates are used to calculate the necessary chemical kinetic times. This time is regressed over the complete initial conditions using the Excel regression routine. Chemical kinetic time equations for H2 and NOx are obtained for H2/air fuel and for the H2/O2. A similar correlation is also developed using data from NASA s Chemical Equilibrium Applications (CEA) code to determine the equilibrium temperature (T4) as a function of overall fuel/air ratio, pressure and initial temperature (T3). High values of the regression coefficient R2 are obtained.

  16. Summary of Simplified Two Time Step Method for Calculating Combustion Rates and Nitrogen Oxide Emissions for Hydrogen/Air and Hydrogen/Oxygen

    NASA Technical Reports Server (NTRS)

    Marek, C. John; Molnar, Melissa

    2005-01-01

    A simplified single rate expression for hydrogen combustion and nitrogen oxide production was developed. Detailed kinetics are predicted for the chemical kinetic times using the complete chemical mechanism over the entire operating space. These times are then correlated to the reactor conditions using an exponential fit. Simple first order reaction expressions are then used to find the conversion in the reactor. The method uses a two time step kinetic scheme. The first time averaged step is used at the initial times with smaller water concentrations. This gives the average chemical kinetic time as a function of initial overall fuel air ratio, temperature, and pressure. The second instantaneous step is used at higher water concentrations (greater than l x 10(exp -20)) moles per cc) in the mixture which gives the chemical kinetic time as a function of the instantaneous fuel and water mole concentrations, pressure and temperature (T(sub 4)). The simple correlations are then compared to the turbulent mixing times to determine the limiting properties of the reaction. The NASA Glenn GLSENS kinetics code calculates the reaction rates and rate constants for each species in a kinetic scheme for finite kinetic rates. These reaction rates are used to calculate the necessary chemical kinetic times. This time is regressed over the complete initial conditions using the Excel regression routine. Chemical kinetic time equations for H2 and NOx are obtained for H2/Air fuel and for H2/O2. A similar correlation is also developed using data from NASA's Chemical Equilibrium Applications (CEA) code to determine the equilibrium temperature (T(sub 4)) as a function of overall fuel/air ratio, pressure and initial temperature (T(sub 3)). High values of the regression coefficient R squared are obtained.

  17. Effect of varying the combustion parameters on the emissions of carbon monoxide and nitrogen oxides in the exhaust gases from propane-fueled vehicles.

    PubMed

    Roberge, B

    2000-05-01

    Propane-fueled forklifts are one source of carbon monoxide (CO) contamination of workplace air. The previous study carried out by the Quebec Occupational Health and Safety Research Institute dealt with worker exposure to CO during forklift use in buildings. It recommends that exhaust gas emissions be kept below a 1 percent concentration. However, this control has not produced a significant reduction in worker exposure to CO, when factors (ventilation, type of work tasks, and management of vehicle fleet) specific to companies are taken into account. Consequently, a reduction in CO emissions below the threshold of 0.3 percent should be considered. The experience acquired with propane-fueled ice resurfacers can be used to determine the effect of combustion parameters on exhaust gas emissions. It is known that a reduction in CO emissions from ice resurfacers resulted in the appearance of nitrogen oxides (NOx) and eventually in nitrogen dioxide (NO2) poisoning. Few publications present NOx results in relation to the CO measured in the exhaust gases of propane-fueled vehicles. The objective of this study is to define the level to which CO emissions can be reduced without increasing NOx concentrations. This real-situation study quantified the CO, NO, and NOx in the exhaust gases of a fleet of propane-fueled forklifts in relation to the mixture ratio. The results show the impact of the motor speed and mixture ratio on the CO, NO, and NO2 concentrations. They confirm an increase in NOx concentrations when CO concentrations are reduced. They also show that proper maintenance of forklifts combined with optimal adjustments can reduce CO and NOx emissions. The study proposes a compromise between CO and NOx emissions by taking into account worker health and safety as well as vehicle performance. Monitoring must be done to control air quality in work areas and worker exposure to CO and NO2. A forklift preventive maintenance program and general building ventilation are the favored

  18. Investigation of formation of nitrogen compounds in coal combustion. Final report

    SciTech Connect

    Blair, D.W.; Crane, I.D.; Wendt, J.O.L.

    1983-10-01

    This is the final report on DOE contract number DE-AC21-80MC14061. It concerns the formation of nitrogen oxide from fuel-bound nitrogen during coal combustion. The work reported was divided into three tasks. They addressed problems of time-resolving pyrolysis rates of coal under simulated combustion conditions, the combustion of the tar that results from such pyrolysis, and theoretical modeling of the pyrolysis process. In all of these tasks, special attention was devoted to the fate of coal nitrogen. The first two tasks were performed by Exxon Research and Engineering Company. 49 references.

  19. Hybrid process for nitrogen oxides reduction

    SciTech Connect

    Epperly, W.R.; Sprague, B.N.

    1991-09-10

    This patent describes a process for reducing the nitrogen oxide concentration in the effluent from the combustion of a carbonaceous fuel. It comprises introducing into the effluent a first treatment agent comprising a nitrogenous composition selected from the group consisting of urea, ammonia, hexamethylenetetramine, ammonium salts of organic acids, 5- or 6-membered heterocyclic hydrocarbons having at least one cyclic nitrogen, hydroxy amino hydrocarbons, NH{sub 4}-lignosulfonate, fur-furylamine, tetrahydrofurylamine, hexamethylenediamine, barbituric acid, guanidine, guanidine carbonate, biguanidine, guanylurea sulfate, melamine, dicyandiamide, biuret, 1.1{prime}-azobisformamide, methylol urea, methylol urea-urea condensation product, dimethylol urea, methyl urea, dimethyl urea, calcium cyanamide, and mixtures thereof under conditions effective to reduce the nitrogen oxides concentration and ensure the presence of ammonia in the effluent; introducing into the effluent a second treatment agent comprising an oxygenated hydrocarbon at an effluent temperature of about 500{degrees} F. to about 1600{degrees} F. under conditions effective to oxidize nitric oxide in the effluent to nitrogen dioxide and ensure the presence of ammonia at a weight ratio of ammonia to nitrogen dioxide of about 1:5 to about 5:1; and contacting the effluent with an aqueous scrubbing solution having a pH of 12 or lower under conditions effective to cause nitrogen dioxide to be absorbed therein.

  20. Coal combustion by wet oxidation

    SciTech Connect

    Bettinger, J.A.; Lamparter, R.A.; McDowell, D.C.

    1980-11-15

    The combustion of coal by wet oxidation was studied by the Center for Waste Management Programs, of Michigan Technological University. In wet oxidation a combustible material, such as coal, is reacted with oxygen in the presence of liquid water. The reaction is typically carried out in the range of 204/sup 0/C (400/sup 0/F) to 353/sup 0/C (650/sup 0/F) with sufficient pressure to maintain the water present in the liquid state, and provide the partial pressure of oxygen in the gas phase necessary to carry out the reaction. Experimental studies to explore the key reaction parameters of temperature, time, oxidant, catalyst, coal type, and mesh size were conducted by running batch tests in a one-gallon stirred autoclave. The factors exhibiting the greatest effect on the extent of reaction were temperature and residence time. The effect of temperature was studied from 204/sup 0/C (400/sup 0/F) to 260/sup 0/C (500/sup 0/F) with a residence time from 600 to 3600 seconds. From this data, the reaction activation energy of 2.7 x 10/sup 4/ calories per mole was determined for a high-volatile-A-Bituminous type coal. The reaction rate constant may be determined at any temperature from the activation energy using the Arrhenius equation. Additional data were generated on the effect of mesh size and different coal types. A sample of peat was also tested. Two catalysts were evaluated, and their effects on reaction rate presented in the report. In addition to the high temperature combustion, low temperature desulfurization is discussed. Desulfurization can improve low grade coal to be used in conventional combustion methods. It was found that 90% of the sulfur can be removed from the coal by wet oxidation with the carbon untouched. Further desulfurization studies are indicated.

  1. 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. Technical progress report, fourth quarter 1995

    SciTech Connect

    1995-12-31

    This document discusses the technical progress of a US Department of Energy (DOE) Innovative Clean Coal Technology (ICCT) Project demonstrating advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. The project is being conducted at Georgia Power Company`s Plant Hammond Unit 4 (500 MW) near Rome, Georgia. Specifically, the objectives of the projects are: (1) demonstrate in a logical stepwise fashion the short-term NO{sub x} reduction capabilities of the following advanced low NO{sub x} combustion technologies: advanced overfire air (AOFA); low NO{sub x} burners (LNB); LNB with AOFA; and advanced digital controls and optimization strategies; (2) determine the dynamic, long-term emissions characteristics of each of these combustion NO{sub x} reduction methods using sophisticated statistical techniques; (3) evaluate the cost effectiveness of the low NO{sub x} combustion techniques tested; and (4) determine the effects on other combustion parameters (e.g., CO production, carbon carryover, particulate characteristics) of applying the above NO{sub x} reduction methods.

  2. OXIDATION AND DEVOLATILIZATION OF NITROGEN IN COAL CHAR

    EPA Science Inventory

    The reactions of organically-bound nitrogen in coal char during combustion have been studied in a laboratory furnace using size-graded char particles prepared by the pyrolysis of a Montana lignite. The time-resolved variations of nitrogen-to-carbon ratio during char oxidation hav...

  3. Multi-stage combustion using nitrogen-enriched air

    DOEpatents

    Fischer, Larry E.; Anderson, Brian L.

    2004-09-14

    Multi-stage combustion technology combined with nitrogen-enriched air technology for controlling the combustion temperature and products to extend the maintenance and lifetime cycles of materials in contact with combustion products and to reduce pollutants while maintaining relatively high combustion and thermal cycle efficiencies. The first stage of combustion operates fuel rich where most of the heat of combustion is released by burning it with nitrogen-enriched air. Part of the energy in the combustion gases is used to perform work or to provide heat. The cooled combustion gases are reheated by additional stages of combustion until the last stage is at or near stoichiometric conditions. Additional energy is extracted from each stage to result in relatively high thermal cycle efficiency. The air is enriched with nitrogen using air separation technologies such as diffusion, permeable membrane, absorption, and cryogenics. The combustion method is applicable to many types of combustion equipment, including: boilers, burners, turbines, internal combustion engines, and many types of fuel including hydrogen and carbon-based fuels including methane and coal.

  4. Innovative Clean Coal Technology (ICCT): 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. Technical progress report, Second quarter 1992

    SciTech Connect

    Not Available

    1992-08-24

    This quarterly report discusses the technical progress of an Innovative Clean Coal Technology (ICCT) demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (No{sub x}) emissions from coal-fired boilers. The project is being conducted at Georgia Power Company`s Plant Hammond Unit 4 located near Rome, Georgia. The primary goal of this project is the characterization of the low NO{sub x} combustion equipment through the collection and analysis of long-term emissions data. A target of achieving fifty percent NO{sub x} reduction using combustion modifications has been established for the project. The project provides a stepwise retrofit of an advanced overfire air (AOFA) system followed by low NO{sub x} burners (LNB). During each test phase of the project, diagnostic, performance, long-term, and verification testing will be performed. These tests are used to quantify the NO{sub x} reductions of each technology and evaluate the effects of those reductions on other combustion parameters such as particulate characteristics and boiler efficiency.

  5. Innovative Clean Coal Technology (ICCT): 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO[sub x]) emissions from coal-fired boilers

    SciTech Connect

    Not Available

    1992-08-24

    This quarterly report discusses the technical progress of an Innovative Clean Coal Technology (ICCT) demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (No[sub x]) emissions from coal-fired boilers. The project is being conducted at Georgia Power Company's Plant Hammond Unit 4 located near Rome, Georgia. The primary goal of this project is the characterization of the low NO[sub x] combustion equipment through the collection and analysis of long-term emissions data. A target of achieving fifty percent NO[sub x] reduction using combustion modifications has been established for the project. The project provides a stepwise retrofit of an advanced overfire air (AOFA) system followed by low NO[sub x] burners (LNB). During each test phase of the project, diagnostic, performance, long-term, and verification testing will be performed. These tests are used to quantify the NO[sub x] reductions of each technology and evaluate the effects of those reductions on other combustion parameters such as particulate characteristics and boiler efficiency.

  6. Combustion synthesis of complex oxides

    NASA Astrophysics Data System (ADS)

    Ming, Qimin

    Advanced ceramic materials have numerous applications in electronic engineering, chemical engineering, and semiconductor industry. The synthesis of these materials at an economical cost is the bottleneck in the application of these materials. Self-propagating High-temperature Synthesis (SHS) is a new technique for producing these materials for exothermic systems by a combustion wave that propagates and produces high purity products. The full potential of SHS to produce advanced materials has not yet been utilized. In this study, we used SHS to prepare two types of complex oxides: La 1-xSrxCrO3, La0.89Sr0.1 MnO3, powders, used to make interconnect and cathode of solid oxide fuel cells; and chromium- and gallium-doped La1-xSr xFeO3-delta, mixed ionic and electronic conductive powders used to manufacture ceramic membranes for oxygen separation. A thermodynamic feasibility analysis shows that the oxidation of Cr is the main source of heat generation of La1-xSrxCrO 3, which maintains a stable reaction front. Replacing part of the metallic Cr in the reaction mixture by its oxides decreases the combustion temperature and front propagating velocity and modifies the product morphology. The oxygen needed for the Cr oxidation is provided by the decomposition of CrO3 , SrO2, or NaClO4. The predicted and observed combustion temperatures are in reasonable agreement. TG/DTA analyses of La1-xSrxCrO3 indicated that SHS stability was strongly affected by the transport of oxygen between the two regions, in which oxygen was generated by the decomposition of either NaClO4 or CrO3 and that in which it was consumed by the oxidation of Cr. Partial melting at the high combustion temperature during SHS of La 1-xSrxMnO3 increased product homogeneity. The electrical conductivity at 1000°C in air of SHS-produced cathode material (of 180 O-1·cm-1) matches that of the commercial product made by other processes. However, the SHS process provides much higher productivity and decreases processing

  7. Process for the reduction of nitrogen oxides in an effluent

    SciTech Connect

    Epperly, W.R.; Sullivan, J.C.; Sprague, B.N.

    1989-09-05

    This patent describes a process for the reduction of the concentration of nitrogen oxides in the effluent from the combustion of a carbonaceous fuel. The process comprises introducing a heterocyclic hydrocarbon selected from the group consisting of piperazine, piperidine, pyrazine, pyrazole, imidazole, oxazolidone, pyrrole and pyrrolidine into the effluent having an effluent temperature of greater than about 1200{sup 0}F. under conditions effective to reduce the concentration of nitrogen oxides in the effluent.

  8. High-temperature control technology for nitrogen oxides

    SciTech Connect

    Casleton, K.H.; Kothari, V.P.; Williams, M.C. )

    1990-01-01

    This paper presents an overview of high- temperature, high-pressure control technology for nitrogen compounds. The origin and evolution of nitrogen oxide compounds and their precursors in advanced coal-conversion systems is discussed. The possible application of nitrogen oxide control technology in advanced coal-conversion system such as the simplified integrated gasification combined cycle (IGCC), pressurized fluidized-bed combustion (PFBC), coal- fueled diesel (CFD), molten carbonate fuel cell (MCFC), and direct coal-fueled turbine (DCFT) systems is discussed. Among the technologies considered are: catalytic decomposition of ammonia, staged combustion for ammonia and NO{sub x}, NO{sub x} reduction using char, and electrochemical reduction of NO{sub x}. The operating conditions for each nitrogen oxide control technology are given.

  9. Low NOx combustion using cogenerated oxygen and nitrogen streams

    DOEpatents

    Kobayashi, Hisashi; Bool, Lawrence E.; Snyder, William J.

    2009-02-03

    Combustion of hydrocarbon fuel is achieved with less formation of NOx by feeding the fuel into a slightly oxygen-enriched atmosphere, and separating air into oxygen-rich and nitrogen-rich streams which are fed separately into the combustion device.

  10. LOW NOX STRATEGY FOR COMBUSTING HIGH NITROGEN CONTENT FUELS

    EPA Science Inventory

    The report gives results of an evaluation of a multistaged combustion urner (designed for in-furnace NOx control and high combustion efficieiicy) for [high nitrogen content fuel and waste incineration application in a 1.0 MW package boiler. simulator. A low NOx precombustion cham...

  11. Nitrogen oxides storage catalysts containing cobalt

    DOEpatents

    Lauterbach, Jochen; Snively, Christopher M.; Vijay, Rohit; Hendershot, Reed; Feist, Ben

    2010-10-12

    Nitrogen oxides (NO.sub.x) storage catalysts comprising cobalt and barium with a lean NO.sub.x storage ratio of 1.3 or greater. The NO.sub.x storage catalysts can be used to reduce NO.sub.x emissions from diesel or gas combustion engines by contacting the catalysts with the exhaust gas from the engines. The NO.sub.x storage catalysts can be one of the active components of a catalytic converter, which is used to treat exhaust gas from such engines.

  12. Innovative clean coal technology: 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NOx) emissions from coal-fired boilers. Final report, Phases 1 - 3B

    SciTech Connect

    1998-01-01

    This report presents the results of a U.S. Department of Energy (DOE) Innovative Clean Coal Technology (ICCT) project demonstrating advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NOx) emissions from coal-fired boilers. The project was conducted at Georgia Power Company`s Plant Hammond Unit 4 located near Rome, Georgia. The technologies demonstrated at this site include Foster Wheeler Energy Corporation`s advanced overfire air system and Controlled Flow/Split Flame low NOx burner. The primary objective of the demonstration at Hammond Unit 4 was to determine the long-term effects of commercially available wall-fired low NOx combustion technologies on NOx emissions and boiler performance. Short-term tests of each technology were also performed to provide engineering information about emissions and performance trends. A target of achieving fifty percent NOx reduction using combustion modifications was established for the project. Short-term and long-term baseline testing was conducted in an {open_quotes}as-found{close_quotes} condition from November 1989 through March 1990. Following retrofit of the AOFA system during a four-week outage in spring 1990, the AOFA configuration was tested from August 1990 through March 1991. The FWEC CF/SF low NOx burners were then installed during a seven-week outage starting on March 8, 1991 and continuing to May 5, 1991. Following optimization of the LNBs and ancillary combustion equipment by FWEC personnel, LNB testing commenced during July 1991 and continued until January 1992. Testing in the LNB+AOFA configuration was completed during August 1993. This report provides documentation on the design criteria used in the performance of this project as it pertains to the scope involved with the low NOx burners and advanced overfire systems.

  13. Innovative Clean Coal Technology (ICCT): 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. Technical progress report, Fourth quarter 1992

    SciTech Connect

    Not Available

    1992-12-31

    This quarterly report discusses the technical progress of an Innovative Clean Coal Technology (ICCT) demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. The primary goal of this project is the characterization of the low NO{sub x} combustion equipment through the collection and analysis of long-term emissions data. A target of achieving fifty percent NO{sub x} reduction using combustion modifications has been established for the project. The project provides a stepwise retrofit of an advanced overfire air (AOFA) system followed by low NO{sub x} burners (LNB). During each test phase of the project, diagnostic, performance, long-term, and verification testing will be performed. These tests are used to quantify the NO{sub x } reductions of each technology and evaluate the effects of those reductions on other combustion parameters such as particulate characteristics and boiler efficiency. Baseline, AOFA, and LNB without AOFA test segments have been completed. Analysis of the 94 days of LNB tong-term data collected show the full load NO{sub x} emission levels to be approximately 0.65 lb/MBtu. Flyash LOI values for the LNB configuration are approximately 8 percent at full load. Corresponding values for the AOFA configuration are 0.94 lb/MBtu and approximately 10 percent. Abbreviated diagnostic tests for the LNB+AOFA configuration indicate that at 500 MWe, NO{sub x} emissions are approximately 0.55 lb/MBtu with corresponding flyash LOI values of approximately 11 percent. For comparison, the long-term, full load, baseline NO{sub x} emission level was approximately 1.24 lb/MBtu at 5.2 percent LOI. Comprehensive testing of the LNB+AOFA configuration will be performed when the stack particulate emissions issue is resolved.

  14. Effect of fuel nitrogen and hydrogen content on emissions in hydrocarbon combustion

    NASA Technical Reports Server (NTRS)

    Bittker, D. A.; Wolfbrandt, G.

    1981-01-01

    How the emissions of nitrogen oxides and carbon monoxide are affected by: (1) the decreased hydrogen content and (2) the increased organic nitrogen content of coal derived fuels is investigated. Previous CRT experimental work in a two stage flame tube has shown the effectiveness of rich lean two stage combustion in reducing fuel nitrogen conversion to nitrogen oxides. Previous theoretical work gave preliminary indications that emissions trends from the flame tube experiment could be predicted by a two stage, well stirred reactor combustor model using a detailed chemical mechanism for propane oxidation and nitrogen oxide formation. Additional computations are reported and comparisons with experimental results for two additional fuels and a wide range of operating conditions are given. Fuels used in the modeling are pure propane, a propane toluene mixture and pure toluene. These give hydrogen contents 18, 11 and 9 percent by weight, respectively. Fuel bound nitrogen contents of 0.5 and 1.0 percent were used. Results are presented for oxides of nitrogen and also carbon monoxide concentrations as a function of primary equivalence ratio, hydrogen content and fuel bound nitrogen content.

  15. 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. Technical progress report, second quarter 1995

    SciTech Connect

    1995-12-31

    This quarterly report discusses the technical progress of an Innovative Clean Coal Technology (ICCT) demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. The project is being conducted at Georgia Power Company`s Plant Hammond Unit 4 located near Rome, Georgia. The primary goal of this project is the characterization of the low NO{sub x} combustion equipment through the collection and analysis of long-term emissions data. The project provides a stepwise evaluation of the following NO{sub x} reduction technologies: advanced overfire air (AOFA), low NO{sub x} burners (LNB), LNB with AOFA, and advanced digital controls and optimization strategies. The project has completed the baseline, AOFA, LNB, and LNB + AOFA test segments, fulfilling all testing originally proposed to DOE. Phase 4 of the project, demonstration of advanced control/optimization methodologies for NO{sub x} abatement, is now in progress. The methodology selected for demonstration at Hammond Unit 4 is the Generic NO{sub x} Control Intelligent System (GNOCIS), which is being developed by a consortium consisting of the Electric Power Research institute, PowerGen, Southern Company, Radian Corporation, U.K. Department of Trade and Industry, and US DOE. GNOCIS is a methodology that can result in improved boiler efficiency and reduced NO{sub x} emissions from fossil fuel fired boilers. Using a numerical model of the combustion process, GNOCIS applies an optimizing procedure to identify the best set points for the plant on a continuous basis. GNOCIS is designed to operate in either advisory or supervisory modes. Prototype testing of GNOCIS is in progress at Alabama Power`s Gaston Unit 4 and PowerGen`s Kingsnorth Unit 1.

  16. Method of removing oxides of sulfur and oxides of nitrogen from exhaust gases

    DOEpatents

    Walker, Richard J.

    1986-01-01

    A continuous method is presented for removing both oxides of sulfur and oxides of nitrogen from combustion or exhaust gases with the regeneration of the absorbent. Exhaust gas is cleaned of particulates and HCl by a water scrub prior to contact with a liquid absorbent that includes an aqueous solution of bisulfite and sulfite ions along with a metal chelate, such as, an iron or zinc aminopolycarboxylic acid. Following contact with the combustion gases the spent absorbent is subjected to electrodialysis to transfer bisulfite ions into a sulfuric acid solution while splitting water with hydroxide and hydrogen ion migration to equalize electrical charge. The electrodialysis stack includes alternate layers of anion selective and bipolar membranes. Oxides of nitrogen are removed from the liquid absorbent by air stripping at an elevated temperature and the regenerated liquid absorbent is returned to contact with exhaust gases for removal of sulfur oxides and nitrogen oxides.

  17. Generation and reduction of nitrogen oxides in firing different kinds of fuel in a circulating fluidized bed

    NASA Astrophysics Data System (ADS)

    Munts, V. A.; Munts, Yu. G.; Baskakov, A. P.; Proshin, A. S.

    2013-11-01

    The processes through which nitrogen oxides are generated and reduced in the course of firing different kinds of fuel in a circulating fluidized bed are addressed. All experimental studies were carried by the authors on their own laboratory installations. To construct a model simulating the generation of nitrogen oxides, the fuel combustion process in a fluidized bed was subdivided into two stages: combustion of volatiles and combustion of coke residue. The processes through which nitrogen oxides are generated and reduced under the conditions of firing fuel with shortage of oxygen (which is one of efficient methods for reducing nitrogen oxide emissions in firing fuel in a fluidized bed) are considered.

  18. Process for the reduction of nitrogen oxides in an effluent using a heterocyclic hydrocarbon

    SciTech Connect

    Epperly, W.R.; Sullivan, J.C.

    1989-12-19

    This patent describes a process for the reduction of the concentration of nitrogen oxides in the effluent from the combustion of a carbonaceous fuel. The process comprises injecting a treatment agent which comprises furfural into the effluent under conditions effective to reduce the concentration of nitrogen oxides in the effluent.

  19. Process for the reduction of nitrogen oxides in an effluent using a hydroxy amino hydrocarbon

    SciTech Connect

    Sullivan, J.C.; Epperly, W.R.

    1989-02-07

    A process is described for the reduction of the concentration of nitrogen oxide in an effluent from the combustion of a carbonaceous fuel, the process comprising injecting a treatment agent comprising a hydroxy amino hydrocarbon into an effluent at an effluent temperature of greater than about 1300/sup 0/F under conditions effective to reduce the concentration of nitrogen oxides in the effluent.

  20. The processes of formation of nitrogen oxides in the boiler furnace BKZ 320-140

    NASA Astrophysics Data System (ADS)

    Vizgavljust, N. V.; Starchenko, A. V.; Gil, A. V.; Taylasheva, T. S.

    2015-01-01

    In this paper, a numerical study of the formation of nitrogen oxides in the combustion chamber based on the model created by Mitchell and Terbellom. The distribution of the height of the furnace temperature and the concentration of nitrogen oxides, as well as a comparison of numerical results with the data of field experiment.

  1. Catalyst for Decomposition of Nitrogen Oxides

    NASA Technical Reports Server (NTRS)

    Schryer, David R. (Inventor); Jordan, Jeffrey D. (Inventor); Akyurtlu, Ates (Inventor); Akyurtlu, Jale (Inventor)

    2015-01-01

    This invention relates generally to a platinized tin oxide-based catalyst. It relates particularly to an improved platinized tin oxide-based catalyst able to decompose nitric oxide to nitrogen and oxygen without the necessity of a reducing gas.

  2. A Mechanistic Investigation of Nitrogen Evolution and Corrosion with Oxy-Combustion

    SciTech Connect

    Dale Tree; Andrew Mackrory; Thomas Fletcher

    2008-12-31

    A premixed, staged, down-fired, pulverized coal reactor and a flat flame burner were used to study the evolution of nitrogen in coal contrasting differences in air and oxy-combustion. In the premixed reactor, the oxidizer was staged to produce a fuel rich zone followed by a burnout zone. The initial nominal fuel rich zone stoichiometric ratio (S.R.) of 0.85 selected produced higher NO reductions in the fuel rich region under oxy-combustion conditions. Air was found to be capable of similar NO reductions when the fuel rich zone was at a much lower S.R. of 0.65. At a S.R. of 0.85, oxy-combustion was measured to have higher CO, unburned hydrocarbons, HCN and NH{sub 3} in the fuel rich region than air at the same S.R. There was no measured difference in the initial formation of NO. The data suggest devolatilization and initial NO formation is similar for the two oxidizers when flame temperatures are the same, but the higher CO{sub 2} leads to higher concentrations of CO and nitrogen reducing intermediates at a given equivalence ratio which increases the ability of the gas phase to reduce NO. These results are supported by flat flame burner experiments which show devolatilization of nitrogen from the coal and char to be similar for air and oxy-flame conditions at a given temperature. A model of premixed combustion containing devolatilization, char oxidation and detailed kinetics captures most of the trends seen in the data. The model suggests CO is high in oxy-combustion because of dissociation of CO{sub 2}. The model also predicts a fraction (up to 20%, dependent on S.R.) of NO in air combustion can be formed via thermal processes with the source being nitrogen from the air while in oxy-combustion equilibrium drives a reduction in NO of similar magnitude. The data confirm oxy-combustion is a superior oxidizer to air for NO control because NO reduction can be achieved at higher S.R. producing better char burnout in addition to NO from recirculated flue gas being reduced

  3. PROCEEDINGS OF THE STATIONARY SOURCE COMBUSTION SYMPOSIUM (2ND), HELD AT NEW ORLEANS, LOUISIANA, ON AUGUST 29-SEPTEMBER 1, 1977. VOLUME IV. FUNDAMENTAL COMBUSTION RESEARCH

    EPA Science Inventory

    Contents: Fundamental combustion research applied to pollution control; Chemical reactions in the conversion of fuel nitrogen to NOx--fuel pyrolysis studies; Fate of fuel nitrogen during pyrolysis and oxidation; Interactions between sulfur oxides and nitrogen oxides in combustion...

  4. 180 MW demonstration of advanced tangentially-fired combustion techniques for the reduction of nitrogen oxide (NO sub x ) emissions from coal-fired boilers

    SciTech Connect

    Not Available

    1991-01-01

    ABB CE's Low NOx Bulk Furnace Staging (LNBFS) System and Low NOx Concentric Firing System (LNCFS) are demonstrated in stepwise fashion. These systems incorporate the concept of advanced overfire air (AOFA), clustered coal nozzles, and offset air. A complete description of the installed technologies is provided in the following section. The primary objective of the Plant Lansing Smith demonstration is to determine the long-term effects of commercially available tangentially-fired low NOx combustion technologies on NOx emissions and boiler performance. Short-term tests of each technology are also being performed to provide engineering information about emissions and performance trends. A target of achieving fifty percent NOx reduction using combustion modifications has been established for the project.

  5. NITROUS OXIDE EMISSIONS FROM FOSSIL FUEL COMBUSTION

    EPA Science Inventory

    The role of coal combustion as a significant global source of nitrous oxide (N2O) emissions was reexamined through on-line emission measurements from six pulverized-coal-fired utility boilers and from laboratory and pilot-scale combustors. The full-scale utility boilers yielded d...

  6. IMPORTANCE OF THE NITROUS OXIDE PATHWAY TO NOX IN LEAN-PREMIXED COMBUSTION

    EPA Science Inventory

    The paper reports results of a study addressing the importance of the different chemical pathways responsible for nitrogen oxides (NOx) formation in lean-premixed combustion, and especially the role of the nitrous oxide pathway relative to the traditional Zeldovich pathway. he pr...

  7. Flame tube parametric studies for control of fuel bound nitrogen using rich-lean two-stage combustion

    NASA Technical Reports Server (NTRS)

    Schultz, D. F.; Wolfbrandt, G.

    1980-01-01

    An experimental parametric study of rich-lean two-stage combustion in a flame tube is described and approaches for minimizing the conversion of fuel-bound nitrogen to nitrogen oxides in a premixed, homogeneous combustion system are evaluated. Air at 672 K and 0.48 MPa was premixed with fuel blends of propane, toluene, and pyridine at primary equivalence ratios ranging from 0.5 to 2.0 and secondary equivalence ratios of 0.5 to 0.7. Distillates of SRC-II, a coal syncrude, were also tested. The blended fuels were proportioned to vary fuel hydrogen composition from 9.0 to 18.3 weight percent and fuel nitrogen composition from zero to 1.5 weight percent. Rich-lean combustion proved effective in reducing fuel nitrogen to NO sub x conversion; conversion rates up to 10 times lower than those normally produced by single-stage combustion were achieved. The optimum primary equivalence ratio, where the least NO sub x was produced and combustion efficiency was acceptable, shifted between 1.4 and 1.7 with changes in fuel nitrogen content and fuel hydrogen content. Increasing levels of fuel nitrogen content lowered the conversion rate, but not enough to avoid higher NO sub x emissions as fuel nitrogen increased.

  8. Sampling nitric oxide from combustion gases.

    NASA Technical Reports Server (NTRS)

    England, C.; Houseman, J.; Teixeira, D. P.

    1973-01-01

    Experimental study of several sampling tube and probe material compositions and designs aimed at preventing nitric oxide reduction when sampling nitric oxide from combustion gases. A 250,000 Btu/h furnace fired with technical grade methane was used for testing the sampling probes over a wide range of air-fuel mixtures. The results obtained include the finding that the use of stainless steel in probes creates inaccuracies in near-stoichiometric and fuel-rich sampling in hydrocarbon flames. For very fuel-rich flames, water cooling is needed even in quartz probes to prevent significant reduction of nitric oxide.-

  9. The Oxides of Nitrogen in Air Pollution.

    ERIC Educational Resources Information Center

    California State Air Resources Board, Sacramento.

    Research on the health effects of oxides of nitrogen and on the role of oxides of nitrogen in producing photochemical smog effects is presented in this report. Prepared by the California State Department of Public Health at the request of the State Legislature, it gives a comprehensive review of available information, as well as the need for air…

  10. Process for the reduction of nitrogen oxides in an effluent

    SciTech Connect

    Epperly, W.R.; Sullivan, J.C.

    1988-09-13

    A process is described for reducing the concentration of nitrogen oxides in an effluent from the combustion of a carbonaceous fuel, which process comprises injecting into the effluent ammonia and an enhancer selected from the group consisting of hexamethylenetetramine, a lower carbon alcohol, a hydroxyl amino hydrocarbon, sugar, furfural, furfural derivatives, an amino acid, a protein-containing composition, mixtures of ortho-, meta-, and para-methyl phenols, guanidine, guanidine carbonate, biguanidine, guanylurea sulfate, melamine, dicyandiamide, calcium cyanamide, biuret, 1,1'-azobisformamide, methylol urea, methylol urea-urea condensation product, dimethylol urea, methyl urea, dimethyl urea, and mixtures thereof, at an effluent temperature above about 1300/sup 0/F and a molar ratio of nitrogen in the ammonia and enhancer to the baseline nitrogen oxides level of about 1:5 to about 6:1 wherein the excess of oxygen in the effluent is no greater than about 6%.

  11. Zinc Oxide-Containing Porous Boron-Carbon-Nitrogen Sheets from Glycine-Nitrate Combustion: Synthesis, Self-Cleaning, and Sunlight-Driven Photocatalytic Activity.

    PubMed

    Bharathidasan, T; Mandalam, Aditya; Balasubramanian, M; Dhandapani, P; Sathiyanarayanan, S; Mayavan, Sundar

    2015-08-26

    We developed a single-step thermal method that enables successful inclusion of ZnO components in the porous boron-carbon-nitrogen (BCN) framework to form a new class of functional hybrid. ZnO-containing BCN hybrids were prepared by treating a mixture of B2O3, glycine, and zinc nitrate at 500 °C. Glycine-nitrate decomposition along with B2O3 acts as a source for ZnO-BCN formation. The incorporation of ZnO onto BCN has extended the photoresponse of ZnO in the visible region, which makes ZnO-BCN a preferable photocatalyst relative to ZnO upon sunlight exposure. It is interesting to note that as-prepared 2D ZnO-BCN sheets dispersed in PDMS form a stable coating over aluminum alloys. The surface exhibited a water contact angle (CA) of 157.6° with 66.6 wt % ZnO-BCN in polydimethylsiloxane (PDMS) and a water droplet (7 μL) roll-off angle of <6° and also demonstrates oil fouling resistant superhydrophobicity. In brief, the present study focuses on the gram scale synthesis of a new class of sunlight-driven photocatalyst and also its application toward the development of superhydrophobic and oleophobic coating. PMID:26252873

  12. Nitrogen and carbon oxides chemistry in the HRS retorting process

    SciTech Connect

    Reynolds, J.G.

    1993-11-12

    The HRS Oil Shale Retort process consists of a pyrolysis section which converts kerogen of the shale to liquid and gaseous products, and a combustion section which burns residual carbon on the shale to heat the process. Average gas concentrations of selected gas phase species were determined from data measured at several placed on the combustion system of the Lawrence Livermore National Laboratory Hot-Recycled-Solids Retort Pilot Plant for representative rich and lean shale runs. The data was measured on-line and in real time by on-line meters (CO{sub 2}, CO, O{sub 2}), mass spectrometry (CO{sub 2}, O{sub 2}, H{sub 2}O, NO, CH{sub 4}, SO{sub 2}, N{sub 2} and Ar), and Fourier transform infrared spectroscopy (CO{sub 2}, CO, H{sub 2}O, NO, N{sub 2}O, NO{sub 2}, CH{sub 4}, SO{sub 2}, NH{sub 3}, and HCN). For both the rich and leans shale runs, the Lift-Pipe Combustor (LFT) exhibited gas concentrations (sampled at the exit of the LFT) indicative of incomplete combustion and oxidation; the Delayed-Fall Combustor (DFC) exhibited gas concentrations (sampled at the annulus and the exit of the DFC) indicative of much more complete combustion and oxidation. The Fluidized-Bed Combustor exhibited gas concentrations which were controlled to a large extent by the injection atmosphere of the FBC. High levels of nitrogen oxides and low levels of CO were detected when full air injection was used, while high levels of CO and low levels of nitrogen-oxides were detected with partial N{sub 2} injection. Sequential sampling limitations and nitrogen balances are also discussed.

  13. COMBUSTION RESEARCH ON THE FATE OF FUEL-NITROGEN UNDER CONDITIONS OF PULVERIZED COAL COMBUSTION

    EPA Science Inventory

    The report gives results of an experimental investigation of coal pyrolysis and oxidation, and char oxidation to determine the effects of temperature and fuel/oxygen equivalence ratio on the conversion of coal-nitrogen to NOx. Experiments involved a laboratory laminar flow furnac...

  14. Reversed flow fluidized-bed combustion apparatus

    DOEpatents

    Shang, Jer-Yu; Mei, Joseph S.; Wilson, John S.

    1984-01-01

    The present invention is directed to a fluidized-bed combustion apparatus provided with a U-shaped combustion zone. A cyclone is disposed in the combustion zone for recycling solid particulate material. The combustion zone configuration and the recycling feature provide relatively long residence times and low freeboard heights to maximize combustion of combustible material, reduce nitrogen oxides, and enhance sulfur oxide reduction.

  15. Process for the reduction of nitrogen oxides in an effluent using sugar

    SciTech Connect

    Epperly, W R.; Sullivan, J.C.

    1989-10-31

    This patent describes a process for the reduction of the concentration of nitrogen oxides in the oxygen-rich effluent from the combustion of a carbonaceous fuel. The process comprising injecting a treatment agent which comprises urea and sugar into an effluent having a temperature of greater than about 1300 {degrees} F. under conditions effective to reduce the concentration of nitrogen oxides in the effluent.

  16. Nitrogen oxides in the troposphere - Global and regional budgets

    NASA Technical Reports Server (NTRS)

    Logan, J. A.

    1983-01-01

    The cycle of nitrogen oxides in the troposphere is discussed from both global and regional perspectives. Global sources for NO(x) are estimated to be of magnitude 50 (+ or - 25) x 10 to the 12th gm N/yr. Nitrogen oxides are derived from combustion of fossil fuels (40 percent) and biomass burning (25 percent) with the balance from lightning and microbial activity in soils. Estimates for the rate of removal of NOx based on recent atmospheric and precipitation chemistry data are consistent with global source strengths derived here. Industrial and agricultural activities provide approximately two thirds of the global source for NOx. In North America, sources from combustion of fossil fuels exceed natural sources by a factor of 3-13. Wet deposition removes about one third of the combustion source of NOx over North America, while dry deposition removes a similar amount. The balance is exported from the continent. Deposition of nitrate in precipitation over eastern Canada and the western Atlantic is clearly influenced by sources of NOx in the eastern United States.

  17. Nitrogen oxide abatement by distributed fuel addition

    SciTech Connect

    Wendt, J.O.L.; Meraab, J.

    1988-06-27

    This research is directed towards the development of engineering guidelines that define the application of distributed fuel addition as a technique for NOx abatement. It is expected that multiple fuel and air addition in the post-flame of a combustion process will increase free radical concentrations which destroy nitrogenous species and thus help them decay toward their equilibrium concentrations, which can be very low in that region of the combustor. Screening experiments were conducted on a laboratory scale downfired combustor. The objective was to compare NOx emissions arising from various combustion configurations, including fuel and/or air staging. Although the primary focus of this research is on NO control, a secondary effort was directed towards the measurement of N2O emissions from various coal combustion processes. N2O has been identified as a trace gas responsible for stratospheric ozone depletion, and has been hypothesized to arise from combustion processes, in amounts roughly proportional to NO emissions. Results presented in this report showed that the ratio N2O/NO was far from constant. The introduction of secondary air into a combustion process was accompanied an increase in N2O emissions. The measured N2O was always less than 10 ppm even under the most favorable combustion conditions. Reburning with premixed fuel and air mixtures was not effective in reducing NO emissions.

  18. Simulation of coal and char nitrogen reactions in combustion. [Final report, September 1992--August 1993

    SciTech Connect

    Kumpaty, S.K.

    1993-10-01

    The observed rate of increase of N{sub 2}O (0.18% to 0.26% annually) is a matter of increasing concern both because N{sub 2}O is a greenhouse gas and has a major and unfavorable influence on the ozone layer (Weiss, 1981). The combustion contribution to the overall nitrous oxide budget is difficult to assess; yet the emission of N{sub 2}O from fluidized bed combustion (FBC) has been identified in the past few years as significant. It was concluded in the European workshop, 1988 that the emission level from a coal-fired fluidized bed boiler is 50--200 ppM but it is only 1--20 ppM in boilers equipped with other types of combustion devices. For this reason it is worthwhile to investigate the emissions from FBC more thoroughly. Gaseous fuels (Miller and Bowman, 1989), but the N{sub 2}O emissions under fluidized bed conditions is poorly understood. In fluidized bed combustion, N{sub 2}O can arise from homogeneous gas phase reactions involving amines and cyano species (Hiltunen et al, 1991) or it can be formed from heterogeneous reactions (eg. char oxidation). Removal of N{sub 2}O can be brought about by gas phase reactions or by catalytic or non-catalytic heterogeneous reduction on char/limestone. This work was carried out with an objective of enhancing the fundamental understanding of coal and char nitrogen reaction pathways in fluidized bed combustion environment. The formation and destruction of HCN and N{sub 2}O under variety of influential parameters were investigated. This simulation contained a nonisothermal single particle combustion in a preheated reactor and a gas phase reaction are designed to stimulate the nitrogen chemistry in a circulating fluidzied bed. The LSODE differential equation solver used for single particle combustion and the CHEMKIN package, developed by Sandia National Laboratories, was applied for gas phase reactions. This computational work was done as an exploratory research program under the solicitation of the DOE fossil energy utilization.

  19. Sources of atmospheric nitrous oxide from combustion

    NASA Technical Reports Server (NTRS)

    Hao, W. M.; Wofsy, S. C.; Mcelroy, M. B.; Beer, J. M.; Toqan, M. A.

    1987-01-01

    Emissions of nitrous oxide (N2O) have been analyzed from industrial boilers and from a large experimental combustor burning natural gas, oil, or coal. Production of N2O and production of NO(x) were observed to be correlated, with an average molar ratio of 0.58:1 (N2O-N:NO). In conventional single-stage combustors, about 14 percent of fuel nitrogen is converted to N2O and 24 percent is converted to NO(x). Conversion of fuel nitrogen to N2O was much less efficient in a two-stage experimental combustor and in wood fires. A model is presented describing emissions of N2O globally, from the beginning of the industrial revolution to the present. It is expected that concentrations of N2O should rise more than 20 percent to about 367 ppb by the year 2050, based on conservative projections of world energy consumption.

  20. Process for the reduction of nitrogen oxides in an effluent

    SciTech Connect

    Epperly, W.R.; Sullivan, J.C.; Sprague, B.N.

    1989-07-04

    This patent describes a process for the reduction of the concentration of nitrogen oxides in the effluent from the combustion of a carbonaceous fuel. The process comprises introducing a treatment agent which comprises a composition selected from the group consisting of NH/sub 4/-lignosulfonate, calcium lignosulfonate, 2-furoic acid, 1,3 dioxolane, tetrahydrofuran, furfurylamine, furfurylalcohol, gluconic acid, citric acid, n-butyl acetate, 1,3 butylene glycol, methylal, tetrahydrofuryl alcohol, furan, fish oil, coumalic acid, furfuryl acetate, tetrahydrofuran 2,3,4,5-tetracarboxylic acid, tetrahydrofurylamine, furylacrylic acid, tetrahydropyran, 2,5-furandimethanol, mannitol, hexamethylenediamine, barbituric acid, acetic anhydride, oxalic acid, mucic acid and d-galactose.

  1. EVALUATION OF TIRE-DERIVED FUEL FOR USE IN NITROGEN OXIDE REDUCTION BY REBURNING

    EPA Science Inventory

    Tire-derived fuel (TDF) was tested in a small-scale (44 kW or 150,000 Btu/hr) combustor to determine its feasibility as a fuel for use in reburning for control of nitrogen oxide (NO). TDF was gravity-fed into upward flowing combustion gases from a primary natural gas flame doped ...

  2. 40 CFR 60.44b - Standard for nitrogen oxides (NOX).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... facility that combusts hazardous waste (as defined by 40 CFR part 261 or 40 CFR part 761) with natural gas.... (See 40 CFR 761.70 for regulations applicable to the incineration of materials containing... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standard for nitrogen oxides (NOX)....

  3. 40 CFR 60.44b - Standard for nitrogen oxides (NOX).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... facility that combusts hazardous waste (as defined by 40 CFR part 261 or 40 CFR part 761) with natural gas.... (See 40 CFR 761.70 for regulations applicable to the incineration of materials containing... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standard for nitrogen oxides (NOX)....

  4. 40 CFR 60.44b - Standard for nitrogen oxides (NOX).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... facility that combusts hazardous waste (as defined by 40 CFR part 261 or 40 CFR part 761) with natural gas.... (See 40 CFR 761.70 for regulations applicable to the incineration of materials containing... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standard for nitrogen oxides (NOX)....

  5. 40 CFR 60.44b - Standard for nitrogen oxides (NOX).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... facility that combusts hazardous waste (as defined by 40 CFR part 261 or 40 CFR part 761) with natural gas.... (See 40 CFR 761.70 for regulations applicable to the incineration of materials containing... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for nitrogen oxides (NOX)....

  6. 40 CFR 60.44b - Standard for nitrogen oxides (NOX).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... facility that combusts hazardous waste (as defined by 40 CFR part 261 or 40 CFR part 761) with natural gas.... (See 40 CFR 761.70 for regulations applicable to the incineration of materials containing... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standard for nitrogen oxides (NOX)....

  7. Low temperature process for the reduction of nitrogen oxides in an effluent

    SciTech Connect

    Epperly, W.R.; Sullivan, J.C.; Sprague, B.N.

    1989-10-10

    This patent describes a process for the reduction of the concentration of nitrogen oxides in the effluent from the combustion of a carbonaceous fuel. The process comprising introducing a treatment agent which comprises an ammonium salt selected from the group consisting of triammonium citrate and ammonium formate into the effluent at an effluent temperature below 1300{sup 0}F.

  8. Fuel-Nitrogen Evolution During Fluidized Bed Oxy-Coal Combustion

    NASA Astrophysics Data System (ADS)

    Sanchez, Astrid; Mondragon, Fanor; Eddings, Eric G.

    FTIR, thermo-gravimetric analysis techniques and molecular modelling were employed to study the effect of CO2 on fuel-nitrogen evolution under oxy-combustion conditions. The main objective is to compare NOx emissions at several molar fractions of O2 using Ar or CO2 as balance gas in a fluidized bed reactor. A char with about 16% N content was prepared by pyrolysis of polyacrylonitrile. This sample facilitated NOx evolution experiments due to the abundance of nitrogen complexes, and aided the identification and quantification of several N species by means ofFTIR. Results indicate that the presence of CO2 enhances NO2 formation. A complementary study was carried out by molecular modelling of the experimental reactions using the Gaussian 03 package. Different heterogeneous and homogeneous interactions between CO2 and char N-species were simulated. The results thus obtained show that the presence of CO2 during combustion can facilitate NCO formation which is a very reactive intermediate species that can be readily oxidized in the gaseous phase.

  9. FIRED HEATERS: NITROGEN OXIDES EMISSIONS AND CONTROLS

    EPA Science Inventory

    The report gives results of a study of nitrogen oxide (NOx) emissions from, and controls for, fired heaters. The petroleum refining and chemical manufacturing industries account for most of fired-heater energy use with an estimated 4600 fired heaters in operation, in these two in...

  10. Nitrogen oxide abatement by distributed fuel addition

    SciTech Connect

    Wendt, J.O.L.; Meraab, J.

    1988-03-25

    The purpose of this project is to develop techniques for nitrogen oxides abatement by distributed fuel addition. The major nitrogen oxide of interest is Nitric Oxide (NO), a precursor to premature forest damage and to acid rain. Recently interest has also been evoked with respect to an additional oxide of nitrogen, namely Nitrous Oxide (N{sub 2}O). Therefore, abatement measures for NO{sub x} are being investigated to determine their influence on N{sub 2}O as well. This report briefly describes the significance of N{sub 2}O emissions to the environment and the urgent need to develop techniques that can reduce emissions of both NO and N{sub 2}O. Reburning through distributed fuel addition may be an effective technique for NO{sub x} (mainly NO) emission control as described in the previous quarterly report. Reburning may also be effective in reducing N{sub 2}O levels. A technique for N{sub 2}O measurement by gas chromatography/electron capture detection was developed during this quarter, and is described in this report. This analysis technique will be used in the proposed experimental study to investigate the effectiveness of reburning on N{sub 2}O control.

  11. 40 CFR 60.332 - Standard for nitrogen oxides.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for nitrogen oxides. 60.332... Turbines § 60.332 Standard for nitrogen oxides. (a) On and after the date on which the performance test... stationary gas turbine, any gases which contain nitrogen oxides in excess of: EC16NO91.020 where:...

  12. 40 CFR 60.55a - Standard for nitrogen oxides.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standard for nitrogen oxides. 60.55a... § 60.55a Standard for nitrogen oxides. On and after the date on which the initial compliance test is... gases that contain nitrogen oxides in excess of 180 parts per million by volume, corrected to 7...

  13. 40 CFR 52.278 - Oxides of nitrogen control.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Contaminants Oxides of Nitrogen submitted on February 21, 1972 and previously approved in 40 CFR 52.223, is... 40 Protection of Environment 3 2012-07-01 2012-07-01 false Oxides of nitrogen control. 52.278... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS California § 52.278 Oxides of nitrogen...

  14. 40 CFR 60.55a - Standard for nitrogen oxides.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standard for nitrogen oxides. 60.55a... § 60.55a Standard for nitrogen oxides. On and after the date on which the initial compliance test is... gases that contain nitrogen oxides in excess of 180 parts per million by volume, corrected to 7...

  15. 40 CFR 60.55a - Standard for nitrogen oxides.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for nitrogen oxides. 60.55a... § 60.55a Standard for nitrogen oxides. On and after the date on which the initial compliance test is... gases that contain nitrogen oxides in excess of 180 parts per million by volume, corrected to 7...

  16. 40 CFR 52.278 - Oxides of nitrogen control.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Contaminants Oxides of Nitrogen submitted on February 21, 1972 and previously approved in 40 CFR 52.223, is... 40 Protection of Environment 3 2011-07-01 2011-07-01 false Oxides of nitrogen control. 52.278... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS California § 52.278 Oxides of nitrogen...

  17. 40 CFR 52.278 - Oxides of nitrogen control.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Contaminants Oxides of Nitrogen submitted on February 21, 1972 and previously approved in 40 CFR 52.223, is... 40 Protection of Environment 3 2013-07-01 2013-07-01 false Oxides of nitrogen control. 52.278... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS California § 52.278 Oxides of nitrogen...

  18. 40 CFR 60.55a - Standard for nitrogen oxides.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standard for nitrogen oxides. 60.55a... § 60.55a Standard for nitrogen oxides. On and after the date on which the initial compliance test is... gases that contain nitrogen oxides in excess of 180 parts per million by volume, corrected to 7...

  19. 40 CFR 52.278 - Oxides of nitrogen control.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Contaminants Oxides of Nitrogen submitted on February 21, 1972 and previously approved in 40 CFR 52.223, is... 40 Protection of Environment 3 2014-07-01 2014-07-01 false Oxides of nitrogen control. 52.278... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS California § 52.278 Oxides of nitrogen...

  20. 40 CFR 52.278 - Oxides of nitrogen control.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Contaminants Oxides of Nitrogen submitted on February 21, 1972 and previously approved in 40 CFR 52.223, is... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Oxides of nitrogen control. 52.278... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS California § 52.278 Oxides of nitrogen...

  1. 40 CFR 60.55a - Standard for nitrogen oxides.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standard for nitrogen oxides. 60.55a... § 60.55a Standard for nitrogen oxides. On and after the date on which the initial compliance test is... gases that contain nitrogen oxides in excess of 180 parts per million by volume, corrected to 7...

  2. The photochemical role of tropospheric nitrogen oxides

    NASA Technical Reports Server (NTRS)

    Chameides, W. L.

    1978-01-01

    The role of nitrogen oxides in the tropospheric photochemical system is re-evaluated in the light of recent measurements of the rate constants for two key reactions. A model for nitrogen oxides is discussed which yields surface NO(x) (NO+NO2) levels approaching 1 ppb in NO(x) source regions but less than 0.1 ppb outside source regions. Applying the new rate coefficients implies increased radical concentrations and a more intense O3 and CO photochemistry. Even for densities of 0.1 ppb or less, NO(x) still leads to significant local O3 production and conversion of HO2 to OH. Unrealistic O3 profiles are obtained with the new rate coefficients for surface NO(x) densities of about 1 ppb, while reasonable agreement with observation is obtained with lower NO(x) densities. Feedback processes between CO, NO(x), OH, and CH4 are also discussed.

  3. The effect of nitrogen on biogas flame propagation characteristic in premix combustion

    NASA Astrophysics Data System (ADS)

    Anggono, Willyanto; Suprianto, Fandi D.; Hartanto, Tan Ivan; Purnomo, Kenny; Wijaya, Tubagus P.

    2016-03-01

    Biogas is one of alternative energy and categorized as renewable energy. The main sources of biogas come from animal waste, garbage, and household waste that are organic waste. Primarily, over 50% of this energy contains methane (CH4). The other substances or inhibitors are nitrogen and carbon dioxide. Previously, carbon dioxide effect on biogas combustion is already experimented. The result shows that carbon dioxide reduces the flame propagation speed of biogas combustion. Then, nitrogen as an inhibitor obviously also brings some effects to the biogas combustion, flame propagation speed, and flame characteristics. Spark ignited cylinder is used for the premixed biogas combustion research. An acrylic glass is used as the material of this transparent cylinder chamber. The cylinder is filled with methane (CH4), oxygen (O2), and nitrogen (N2) with particular percentage. In this experiment, the nitrogen composition are set to 0%, 5%, 10%, 20%, 30%, 40%, and 50%. The result shows that the flame propagation speed is reduced in regard to the increased level of nitrogen. It can also be implied that nitrogen can decrease the biogas combustion rate.

  4. Nitrogen oxide abatement by distributed fuel addition

    SciTech Connect

    Wendt, J.O.L.; Mereb, J.B.

    1991-09-20

    Reburning is examined as a means of NO{sub x} destruction in a 17 kW down-fired pulverized coal combustor. In reburning, a secondary fuel is introduced downstream of the primary flame to produce a reducing zone, favorable to NO destruction, and air is introduced further downstream to complete the combustion. Emphasis is on natural gas reburning and a bituminous coal primary flame. A parametric examination of reburning employing a statistical experimental design, is conducted, complemented by detailed experiments. Mechanisms governing the inter-conversion of nitrogenous species in the fuel rich reburn zone is explored. The effect of reburning on N{sub 2}O emissions, the effect of primary flame mode (premixed and diffusion) and the effect of distributing the reburning fuel, are also investigated.

  5. Nitrogen oxide emissions from coal fired MHD plants

    SciTech Connect

    Chapman, J.N.

    1996-03-01

    In this topical report, the nitrogen oxide emission issues from a coal fired MHD steam combined cycle power plant are summarized, both from an experimental and theoretical/calculational viewpoint. The concept of staging the coal combustion to minimize NO{sub x} is described. The impact of NO{sub x} control design choices on electrical conductivity and overall plant efficiency are described. The results of the NO{sub x} measurements in over 3,000 hours of coal fired testing are summarized. A chemical kinetics model that was used to model the nooks decomposition is described. Finally, optimum design choices for a low nooks plant are discussed and it is shown that the MHD Steam Coal Fired Combined Cycle Power Plant can be designed to operate with nooks emissions less than 0.05 lbm/MMBTU.

  6. NITRIC OXIDE FORMATION DURING PULVERIZED COAL COMBUSTION

    EPA Science Inventory

    Data on the overall conversion of coal-nitrogen to NOx were obtained at 1250 K and 1750 K for a residence time of one second. The conversion of coal-nitrogen to NOx decreased monotonically with increasing fuel/oxygen equivalence ratio and decreased slightly with increasing temper...

  7. AIR QUALITY CRITERIA FOR OXIDES OF NITROGEN (Final, 1993)

    EPA Science Inventory

    This criteria document focuses on a review and assessment of the effects on human health and welfare of the nitrogen oxides, nitric oxide (NO) and nitrogen dioxide (NO2), and the related compounds, nitrites, nitrates, nitrogenous acids, and nitrosamines. Although the emphasis is ...

  8. The next step in chemical propulsion: Oxide-iridium/rhenium combustion chambers

    NASA Astrophysics Data System (ADS)

    Fortini, Arthur J.; Tuffias, Robert H.

    1999-01-01

    Chemical propulsion systems are currently limited by materials issues. Until recently, the state-of-the-art material for liquid propellant combustion chambers was silicide-coated niobium. However, combustion chamber performance demands have exceeded the capabilities of this material system, requiring development of better materials. The iridium/rhenium combustion chamber, comprising a rhenium structural shell with an iridium inner liner for oxidation protection, represents the current state of the art in high-performance, high temperature, long-life propulsion systems using nitrogen tetroxide/monomethyl hydrazine propellant. However, oxygen/hydrogen (O2/H2) and new ``green'' monopropellants under development to replace hydrazine will be significantly more oxidizing at operating temperature. For these more highly aggressive combustion environments, Ultramet has shown that substantial additional life can be obtained by lining the interior of the combustion chamber with a refractory metal oxide, which functions as a thermal and gas diffusion barrier and provides dramatically increased oxidation resistance. Ultramet has fabricated numerous 22-N (5-lbf) thrust chambers with this oxide-iridium/rhenium architecture that have been hot-fire tested at NASA Lewis Research Center in O2/H2 propellant at mixture ratios of 6 and 16, with steady-state exterior wall temperatures ranging from 2433 to 2899 K, comprising the most severe temperature and oxidizing conditions ever utilized. Of the seven chambers tested to date, three failed due to facility problems, and two never failed. The best-performing chamber was hot-fired for 13,595 seconds (227 minutes; 3.8 hours) and showed no visible signs of degradation. Additional chambers are being fabricated for future testing.

  9. The next step in chemical propulsion: Oxide-iridium/rhenium combustion chambers

    SciTech Connect

    Fortini, Arthur J.; Tuffias, Robert H.

    1999-01-22

    Chemical propulsion systems are currently limited by materials issues. Until recently, the state-of-the-art material for liquid propellant combustion chambers was silicide-coated niobium. However, combustion chamber performance demands have exceeded the capabilities of this material system, requiring development of better materials. The iridium/rhenium combustion chamber, comprising a rhenium structural shell with an iridium inner liner for oxidation protection, represents the current state of the art in high-performance, high temperature, long-life propulsion systems using nitrogen tetroxide/monomethyl hydrazine propellant. However, oxygen/hydrogen (O{sub 2}/H{sub 2}) and new 'green' monopropellants under development to replace hydrazine will be significantly more oxidizing at operating temperature. For these more highly aggressive combustion environments, Ultramet has shown that substantial additional life can be obtained by lining the interior of the combustion chamber with a refractory metal oxide, which functions as a thermal and gas diffusion barrier and provides dramatically increased oxidation resistance. Ultramet has fabricated numerous 22-N (5-lb{sub f}) thrust chambers with this oxide-iridium/rhenium architecture that have been hot-fire tested at NASA Lewis Research Center in O{sub 2}/H{sub 2} propellant at mixture ratios of 6 and 16, with steady-state exterior wall temperatures ranging from 2433 to 2899 K, comprising the most severe temperature and oxidizing conditions ever utilized. Of the seven chambers tested to date, three failed due to facility problems, and two never failed. The best-performing chamber was hot-fired for 13,595 seconds (227 minutes; 3.8 hours) and showed no visible signs of degradation. Additional chambers are being fabricated for future testing.

  10. Low-Frequency Combustion Instability Induced by the Combustion Time Lag of Liquid Oxidizer in Hybrid Rocket Motors

    NASA Astrophysics Data System (ADS)

    Morita, Takakazu; Kitagawa, Koki; Yuasa, Saburo; Yamaguchi, Shigeru; Shimada, Toru

    This paper deals with a theoretical analysis of the low-frequency combustion instability induced by the combustion time lag of liquid oxidizer in small-scale hybrid rocket motors. We obtained the determined linear stability limit using the following parameters: the combustion time delay of liquid oxidizer, the residence time of a combustion chamber, injector pressure, chamber pressure, mass flux exponent, O/F, and the polytropic exponent of mixture gas in a combustion chamber. Kitagawa and Yuasa sometimes observed low-frequency oscillations, such as chugging, in their swirling-oxidizer-flow-type hybrid rocket engine. The obtained theoretical stability limit was compared with these experimental data.

  11. Mechanisms and modeling of the effects of additives on the nitrogen oxides emission

    NASA Technical Reports Server (NTRS)

    Kundu, Krishna P.; Nguyen, Hung Lee; Kang, M. Paul

    1991-01-01

    A theoretical study on the emission of the oxides of nitrogen in the combustion of hydrocarbons is presented. The current understanding of the mechanisms and the rate parameters for gas phase reactions were used to calculate the NO(x) emission. The possible effects of different chemical species on thermal NO(x), on a long time scale were discussed. The mixing of these additives at various stages of combustion were considered and NO(x) concentrations were calculated; effects of temperatures were also considered. The chemicals such as hydrocarbons, H2, CH3OH, NH3, and other nitrogen species were chosen as additives in this discussion. Results of these calculations can be used to evaluate the effects of these additives on the NO(x) emission in the industrial combustion system.

  12. Method and apparatus for nitrogen oxide determination

    DOEpatents

    Hohorst, Frederick A.

    1990-01-01

    Method and apparatus for determining nitrogen oxide content in a high temperature process gas, which involves withdrawing a sample portion of a high temperature gas containing nitrogen oxide from a source to be analyzed. The sample portion is passed through a restrictive flow conduit, which may be a capillary or a restriction orifice. The restrictive flow conduit is heated to a temperature sufficient to maintain the flowing sample portion at an elevated temperature at least as great as the temperature of the high temperature gas source, to thereby provide that deposition of ammonium nitrate within the restrictive flow conduit cannot occur. The sample portion is then drawn into an aspirator device. A heated motive gas is passed to the aspirator device at a temperature at least as great as the temperature of the high temperature gas source. The motive gas is passed through the nozzle of the aspirator device under conditions sufficient to aspirate the heated sample portion through the restrictive flow conduit and produce a mixture of the sample portion in the motive gas at a dilution of the sample portion sufficient to provide that deposition of ammonium nitrate from the mixture cannot occur at reduced temperature. A portion of the cooled dilute mixture is then passed to analytical means capable of detecting nitric oxide.

  13. Nox control for high nitric oxide concentration flows through combustion-driven reduction

    DOEpatents

    Yeh, James T.; Ekmann, James M.; Pennline, Henry W.; Drummond, Charles J.

    1989-01-01

    An improved method for removing nitrogen oxides from concentrated waste gas streams, in which nitrogen oxides are ignited with a carbonaceous material in the presence of substoichiometric quantities of a primary oxidant, such as air. Additionally, reductants may be ignited along with the nitrogen oxides, carbonaceous material and primary oxidant to achieve greater reduction of nitrogen oxides. A scrubber and regeneration system may also be included to generate a concentrated stream of nitrogen oxides from flue gases for reduction using this method.

  14. Effect of oxy-combustion flue gas on mercury oxidation.

    PubMed

    Fernández-Miranda, Nuria; Lopez-Anton, M Antonia; Díaz-Somoano, Mercedes; Martínez-Tarazona, M Rosa

    2014-06-17

    This study evaluates the effect of the gases present in a typical oxy-coal combustion atmosphere on mercury speciation and compares it with the mercury speciation produced in conventional air combustion atmospheres. The work was performed at laboratory scale at 150 °C. It was found that the minor constituents (SO2, NOx, and HCl) significantly modify the percentages of Hg(2+) in the gas. The influence of these species on mercury oxidation was demostrated when they were tested individually and also when they were blended in different gas compositions, although the effect was different to the sum of their individual effects. Of the minor constituents, NOx were the main species involved in oxidation of mercury. Moreover, it was found that a large concentration of H2O vapor also plays an important role in mercury oxidation. Around 50% of the total mercury was oxidized in atmospheres with H2O vapor concentrations typical of oxy-combustion conditions. When the atmospheres have similar concentrations of SO2, NO, NO2, HCl, and H2O, the proportion of Hg(0)/Hg(2+) is similar regardless of whether CO2 (oxy-fuel combustion) or N2 (air combustion) are the main components of the gas. PMID:24877895

  15. Catalytic iron oxide for lime regeneration in carbonaceous fuel combustion

    DOEpatents

    Shen, Ming-Shing; Yang, Ralph T.

    1980-01-01

    Lime utilization for sulfurous oxides absorption in fluidized combustion of carbonaceous fuels is improved by impregnation of porous lime particulates with iron oxide. The impregnation is achieved by spraying an aqueous solution of mixed iron sulfate and sulfite on the limestone before transfer to the fluidized bed combustor, whereby the iron compounds react with the limestone substrate to form iron oxide at the limestone surface. It is found that iron oxide present in the spent limestone acts as a catalyst to regenerate the spent limestone in a reducing environment. With only small quantities of iron oxide the calcium can be recycled at a significantly increased rate.

  16. Catalytic combustion of methane by perovskite-type oxide nanoparticles as pollution prevention strategy

    NASA Astrophysics Data System (ADS)

    Zaza, F.; Luisetto, I.; Serra, E.; Tuti, S.; Pasquali, M.

    2016-06-01

    The transition from the existing brown economy towards the desired green economy drives the research efforts to the development of advanced technologies promoting the efficient utilization of energy sources. Catalysis science offers to combustion technology significant opportunity to increase the fuel efficiency by lowering the internal temperature gradients and reduce the environmental impact by lowering local peak temperature and, consequently, thermodynamically inhibiting the nitrogen oxides formation. Alternative catalytic materials are transition metals oxide, including complex oxides with perovskite crystalline structure. The aim of this work is to synthetize lanthanum ferrite perovskites with lanthanum ions partially substituted by strontium ions in order to study the substitution effects on structural properties and redox activity of the original oxide. Lanthanum ferrite oxides partially substituted with different Strontium amount were synthesized by solution combustion method. The perovskite nanopowders obtained were characterized by XRD, SEM, TPR analyses for defining crystalline structure, morphology and redox properties. Finally, the catalytic activity for methane combustion was tested. The most performing catalysts was La0.6Sr0.4FeO3 having the highest oxygen vacancy concentration as revealed by TPR analysis.

  17. 40 CFR 91.318 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... check, and calibration test procedures specified in 40 CFR part 1065, subparts C and D, may be used in... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Oxides of nitrogen analyzer... Provisions § 91.318 Oxides of nitrogen analyzer calibration. (a) Calibrate the chemiluminescent oxides...

  18. 40 CFR 91.318 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... check, and calibration test procedures specified in 40 CFR part 1065, subparts C and D, may be used in... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Oxides of nitrogen analyzer... Provisions § 91.318 Oxides of nitrogen analyzer calibration. (a) Calibrate the chemiluminescent oxides...

  19. 40 CFR 91.318 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... check, and calibration test procedures specified in 40 CFR part 1065, subparts C and D, may be used in... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Oxides of nitrogen analyzer... Provisions § 91.318 Oxides of nitrogen analyzer calibration. (a) Calibrate the chemiluminescent oxides...

  20. 40 CFR 91.318 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... check, and calibration test procedures specified in 40 CFR part 1065, subparts C and D, may be used in... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Oxides of nitrogen analyzer... Provisions § 91.318 Oxides of nitrogen analyzer calibration. (a) Calibrate the chemiluminescent oxides...

  1. 40 CFR 91.318 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... check, and calibration test procedures specified in 40 CFR part 1065, subparts C and D, may be used in... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Oxides of nitrogen analyzer calibration... Provisions § 91.318 Oxides of nitrogen analyzer calibration. (a) Calibrate the chemiluminescent oxides...

  2. Control of nitrogen oxide (NO{sub x}) emissions using a metal oxide sorbent

    SciTech Connect

    Kimm, L.T.; Allen, E.R.

    1995-12-31

    The combustion of carbonaceous jet fuels during jet engine testing produces significant quantities of nitrogen oxides (NO{sub x}). Two stable gaseous oxides, nitric oxide (NO) and nitrogen dioxide (NO{sub 2}), are the predominant air pollutants of environmental and health concern. This study was conducted to provide fundamental data on the time and operating variable dependence of NO{sub x} removal efficiencies, intrinsic and apparent chemical kinetics, and removal mechanisms. The study systematically addressed individual exhaust gas components. A magnesium oxide-vermiculite sorbent was incorporated into a packed-bed reactor in a controlled temperature environment. Sorption temperatures between 373 and 473 K were used. In general, it was more difficult to remove NO compared to NO{sub 2}. The removal of each species was independently affected by the variables evaluated. Observations suggest that there may be a fixed NO sorption capacity. A first-order kinetic expression appeared to describe NO{sub 2} removal and was used as a basis to model NO{sub 2} decay. Further findings supported a step-wise reaction mechanism where NO{sub 2} is removed, producting NO by a reaction pathway independent of thermal product decomposition, which ceases when NO{sub 2} is no longer being removed by the sorbent.

  3. 40 CFR 60.72 - Standard for nitrogen oxides.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standard for nitrogen oxides. 60.72... Plants § 60.72 Standard for nitrogen oxides. (a) On and after the date on which the performance test...) Contain nitrogen oxides, expressed as NO2, in excess of 1.5 kg per metric ton of acid produced (3.0 lb...

  4. 40 CFR 60.72 - Standard for nitrogen oxides.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standard for nitrogen oxides. 60.72... Plants § 60.72 Standard for nitrogen oxides. (a) On and after the date on which the performance test...) Contain nitrogen oxides, expressed as NO2, in excess of 1.5 kg per metric ton of acid produced (3.0 lb...

  5. 40 CFR 60.72 - Standard for nitrogen oxides.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standard for nitrogen oxides. 60.72... Plants § 60.72 Standard for nitrogen oxides. (a) On and after the date on which the performance test...) Contain nitrogen oxides, expressed as NO2, in excess of 1.5 kg per metric ton of acid produced (3.0 lb...

  6. 40 CFR 60.72 - Standard for nitrogen oxides.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for nitrogen oxides. 60.72... Plants § 60.72 Standard for nitrogen oxides. (a) On and after the date on which the performance test...) Contain nitrogen oxides, expressed as NO2, in excess of 1.5 kg per metric ton of acid produced (3.0 lb...

  7. 40 CFR 60.72 - Standard for nitrogen oxides.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standard for nitrogen oxides. 60.72... Plants § 60.72 Standard for nitrogen oxides. (a) On and after the date on which the performance test...) Contain nitrogen oxides, expressed as NO2, in excess of 1.5 kg per metric ton of acid produced (3.0 lb...

  8. Technology for controlling emissions of oxides of nitrogen from supersonic cruise aircraft

    NASA Technical Reports Server (NTRS)

    Reck, G. M.; Rudey, R. A.

    1976-01-01

    Various experiments are sponsored and conducted by NASA to explore the potential of advanced combustion techniques for controlling aircraft engine emissions into the upper atmosphere. Of particular concern are the oxide of nitrogen (NOx) emissions into the stratosphere. The experiments utilize a wide variety of approaches varying from advanced combustor concepts to fundamental flame tube experiments. Results are presented which indicate that substantial reductions in cruise NOx emissions should be achievable in future aircraft engines. A major NASA program is described which focuses the many fundamental experiments into a planned evolution and demonstration of the prevaporized-premixed combustion technique in a full-scale engine.

  9. Analysis of effect of flameholder characteristics on lean, premixed, partially vaporized fuel-air mixtures quality and nitrogen oxides emissions

    NASA Technical Reports Server (NTRS)

    Cooper, L. P.

    1981-01-01

    An analysis was conducted of the effect of flameholding devices on the precombustion fuel-air characteristics and on oxides of nitrogen (NOx) emissions for combustion of premixed partially vaporized mixtures. The analysis includes the interrelationships of flameholder droplet collection efficiency, reatomization efficiency and blockage, and the initial droplet size distribution and accounts for the contribution of droplet combustion in partially vaporized mixtures to NOx emissions. Application of the analytical procedures is illustrated and parametric predictions of NOx emissions are presented.

  10. Effect of fuel-air-ratio nonuniformity on emissions of nitrogen oxides

    NASA Technical Reports Server (NTRS)

    Lyons, V. J.

    1981-01-01

    The inlet fuel-air ratio nonuniformity is studied to deterine how nitrogen oxide (NOx) emissions are affected. An increase in NOx emissions with increased fuel-air ratio nonuniformity for average equivalence ratios less than 0.7 and a decrease in NOx emissions for average equivalence ratios near stoichiometric is predicted. The degree of uniformityy of fuel-air ratio profiles that is necessary to achieve NOx emissions goals for actual engines that use lean, premixed, prevaporized combustion systems is determined.

  11. Prevaporization and premixing to obtain low oxides of nitrogen in gas turbine combustors

    NASA Technical Reports Server (NTRS)

    Roffe, G.; Ferri, A.

    1975-01-01

    Tests were conducted to determine the effectiveness of prevaporization and premixing in reducing the formation of oxides of nitrogen in a gas turbine type combustor using liquid JP-5 fuel at the supersonic cruise condition. The combustor inlet temperature was 833 K (1500 R) at a pressure of 4 atmospheres and a reference velocity of 46 m/sec (150 ft/sec). An order of magnitude reduction in nitric oxide emissions was achieved. Nitric oxide emission indices as low as 0.6 gm NO2/kg fuel were measured at an equivalence ratio of 0.29 with one percent combustion inefficiency without vitiation of the mixer stream.

  12. NITROGEN OXIDES REACTIONS WITHIN URBAN PLUMES TRANSPORTED OVER THE OCEAN

    EPA Science Inventory

    The report describes an airborne measurements program in the downwind urban plume of Boston. The variables measured included ozone, nitric oxide, oxides of nitrogen, nitric acid, peroxyacetylnitrate, carbon monoxide, nonmethane hydrocarbon, freon-11, C1-C5 hydrocarbons, condensat...

  13. NOx formation from the combustion of monodisperse n-heptane sprays doped with fuel-nitrogen additives

    NASA Technical Reports Server (NTRS)

    Sarv, Hamid; Cernansky, Nicholas P.

    1989-01-01

    A series of experiments with simulated synthetic fuels were conducted in order to investigate the effect of droplet size on the conversion of fuel-nitrogen to NOx. Pyridine and pyrrole were added to n-heptane as nitrogen-containing additives and burned as monodisperse fuel droplets under various operating conditions in a spray combustion facility. The experimental results indicate that under stoichiometric and fuel-rich conditions, reducing the droplet size increases the efficiency of fuel-N conversion to NOx. This observation is associated with improved oxidation of the pyrolysis fragments of the additive by better oxygen penetration through the droplet flame zone. The dominant reactions by which fuel-N is transformed to NOx were also considered analytically by a premixed laminar flame code. The calculations are compared to the small droplet size results.

  14. APPLICATION OF STAGED COMBUSTION AND REBURNING TO THE CO-FIRING OF NITROGEN-CONTAINING WASTES

    EPA Science Inventory

    The paper gives results of an evaluation of a 0.6 MW precombustion chamber burner, designed for in-furnace NOx control, high combustion efficiency, and retrofit applications, for use with high nitrogen content fuel/waste mixtures. he 250- to 750- ms residence time precombustion c...

  15. Modeling Nitrogen Oxides in the Lower Stratosphere

    NASA Technical Reports Server (NTRS)

    Kawa, S. Randy; Einaudi, Franco (Technical Monitor)

    2001-01-01

    This talk will focus on the status of current understanding (not a historical review) as regards modeling nitrogen oxides (NOy) in the lower stratosphere (LS). The presentation will be organized around three major areas of process understanding: 1) NOy sources, sinks, and transport to the LS, 2) NOy species partitioning, and 3) polar multiphase processes. In each area, process topics will be identified with an estimate of the degree of confidence associated with their representation in numerical models. Several exotic and/or speculative processes will also be discussed. Those topics associated with low confidence or knowledge gaps, weighted by their prospective importance in stratospheric chemical modeling, will be collected into recommendations for further study. Suggested approaches to further study will be presented for discussion.

  16. Catalyst for reduction of nitrogen oxides

    DOEpatents

    Ott, Kevin C.

    2010-04-06

    A Selective Catalytic Reduction (SCR) catalyst was prepared by slurry coating ZSM-5 zeolite onto a cordierite monolith, then subliming an iron salt onto the zeolite, calcining the monolith, and then dipping the monolith either into an aqueous solution of manganese nitrate and cerium nitrate and then calcining, or by similar treatment with separate solutions of manganese nitrate and cerium nitrate. The supported catalyst containing iron, manganese, and cerium showed 80 percent conversion at 113 degrees Celsius of a feed gas containing nitrogen oxides having 4 parts NO to one part NO.sub.2, about one equivalent ammonia, and excess oxygen; conversion improved to 94 percent at 147 degrees Celsius. N.sub.2O was not detected (detection limit: 0.6 percent N.sub.2O).

  17. EPA`s integrated nitrogen oxides strategy

    SciTech Connect

    Grano, D.H.

    1997-12-31

    Nitrogen oxides (NO{sub x}) are highly reactive and play a major role in the formation of various gases and particles in the atmosphere which lead to harmful effects on human health and welfare. This paper briefly describes the multiple impacts on human health and welfare that result from emissions of NO{sub x} and describes EPA`s strategy to integrate NO{sub x} reductions from various mobile and stationary sources in a balanced manner to achieve environmental benefits. Based on modeling information, it is clear that substantial reductions in NO{sub x} emissions over large geographic areas are needed if many densely populated areas of the nation are to attain the national ambient air quality standard for ozone. In addition to attainment of the health standard for ozone, the reduction of NO{sub x} emissions will also likely improve the nation`s environment by reducing adverse impacts of acid deposition, eutrophication of waterbodies, global warming, nitrogen dioxide, particulate matter, stratospheric ozone depletion, toxics, and visibility.

  18. Nitrogen oxide pullution may spark seeds` growth

    SciTech Connect

    Malakoff, D.A.

    1997-05-23

    Could a common air pollutant be fooling the seeds of some wild plants into germinating when conditions are deadly to the seedlings? That`s the provocative question raised by a finding reported in this issue. Two ecologists have learned that the seeds of a common California wildflower can be prompted to germinate by exposure to nitrogen oxides, gases produced by both natural wildfires and motor vehicles and power plants. Botanists have long recognized that many plants inhabiting fire-prone areas, such as the and forests of the Southwest and the shrub-choked hillsides of southern California, grow best on freshly burned-over land. Scorched soils are often rich in nutrients, such as nitrogen and phosphorus released from burned vegetation, and they are free of shrubs that can otherwise shade sun-loving seedlings. For many of these phoenix like plants, a fire`s searing heat is what prompts them to rise from the ashes. Heat cracks the hard, outer coat of seeds that can lie dormant in the soil for decades. This allows water to seep in, spurring growth.

  19. Intercontinental transport of nitrogen oxide pollution plumes

    NASA Astrophysics Data System (ADS)

    Wenig, M.; Spichtinger, N.; Stohl, A.; Held, G.; Beirle, S.; Wagner, T.; Jähne, B.; Platt, U.

    2002-11-01

    We describe the first satellite observation of intercontinental transport of nitrogen oxides emitted by power plants, verified by simulations with a particle tracer model. The analysis of such episodes shows that anthropogenic NOx plumes may influence the atmospheric chemistry thousands of kilometers away from its origin, as well as the ocean they traverse due to nitrogen fertilization. This kind of monitoring became possible by applying an improved algorithm to extract the tropospheric fraction of NO2 from the spectral data coming from the GOME instrument. As an example we show the observation of NO2 in the time period 4--14 May, 1998, from the South African Plateau to Australia which was possible due to favourable weather conditions during that time period which availed the satellite measurement. This episode was also simulated with the Lagrangian particle dispersion model FLEXPART which uses NOx emissions taken from an inventory for industrial emissions in South Africa and is driven with analyses from the European Centre for Medium-Range Weather Forecasts. Additionally lightning emissions were added by utilizing Lightning Imaging Sensor data. Lightning NOx was found to amount to around 10% of the resulting concentrations. Both, the measured and simulated emission plume show matching patterns while traversing the Indian Ocean to Australia and show great resemblance to the aerosol and CO2 transport observed by Piketh et al. (2000)

  20. Chemical-looping combustion of coal with metal oxide oxygen carriers

    SciTech Connect

    Ranjani Siriwardane; Hanjing Tian; George Richards; Thomas Simonyi; James Poston

    2009-08-15

    The combustion and reoxidation properties of direct coal chemical-looping combustion (CLC) over CuO, Fe{sub 2}O{sub 3}, CO{sub 3}O{sub 4}, NiO, and Mn{sub 2}O{sub 3} were investigated using thermogravimetric analysis (TGA) and bench-scale fixed-bed flow reactor studies. When coal is heated in either nitrogen or carbon dioxide (CO{sub 2}), 50% of weight loss was observed because of partial pyrolysis, consistent with the proximate analysis. Among various metal oxides evaluated, CuO showed the best reaction properties: CuO can initiate the reduction reaction as low as 500{sup o}C and complete the full combustion at 700{sup o}C. In addition, the reduced copper can be fully reoxidized by air at 700{sup o}C. The combustion products formed during the CLC reaction of the coal/metal oxide mixture are CO{sub 2} and water, while no carbon monoxide was observed. Multicycle TGA tests and bench-scale fixed-bed flow reactor tests strongly supported the feasibility of CLC of coal by using CuO as an oxygen carrier. Scanning electron microscopy (SEM) images of solid reaction products indicated some changes in the surface morphology of a CuO-coal sample after reduction/oxidation reactions at 800 {sup o}C. However, significant surface sintering was not observed. The interactions of fly ash with metal oxides were investigated by X-ray diffraction and thermodynamic analysis. Overall, the results indicated that it is feasible to develop CLC with coal by metal oxides as oxygen carriers. 22 refs., 12 figs., 2 tabs.

  1. Purification of crude hexafluoroacetone containing nitrogen oxides and sulfur dioxide

    SciTech Connect

    Bonfield, J. H.; Karsay, B. I.

    1984-09-25

    Crude hexafluoroacetone containing as impurities nitrogen oxides and sulfur dioxide is purified by admixing with water to form an aqueous solution, admixing the aqueous solution with concentrated sulfuric acid or oleum to form a vapor and scrubbing the vapor with liquid concentrated sulfuric acid to produce purified anhydrous hexafluoroacetone. The sulfur dioxide and nitrogen oxides interact with the aqueous solution and conc

  2. 40 CFR 60.44 - Standard for nitrogen oxides (NOX).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standard for nitrogen oxides (NOX). 60...-Fired Steam Generators § 60.44 Standard for nitrogen oxides (NOX). (a) Except as provided under.../J heat input (0.30 lb/MMBtu) derived from liquid fossil fuel, liquid fossil fuel and wood...

  3. 40 CFR 60.44 - Standard for nitrogen oxides (NOX).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standard for nitrogen oxides (NOX). 60...-Fired Steam Generators § 60.44 Standard for nitrogen oxides (NOX). (a) Except as provided under.../J heat input (0.30 lb/MMBtu) derived from liquid fossil fuel, liquid fossil fuel and wood...

  4. 40 CFR 60.44 - Standard for nitrogen oxides (NOX).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for nitrogen oxides (NOX). 60... nitrogen oxides (NOX). (a) Except as provided under paragraph (e) of this section, on and after the date on...) derived from gaseous fossil fuel. (2) 129 ng/J heat input (0.30 lb/MMBtu) derived from liquid fossil...

  5. 40 CFR 60.44 - Standard for nitrogen oxides (NOX).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standard for nitrogen oxides (NOX). 60... nitrogen oxides (NOX). (a) Except as provided under paragraph (e) of this section, on and after the date on...) derived from gaseous fossil fuel. (2) 129 ng/J heat input (0.30 lb/MMBtu) derived from liquid fossil...

  6. 40 CFR 60.44 - Standard for nitrogen oxides (NOX).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standard for nitrogen oxides (NOX). 60...-Fired Steam Generators § 60.44 Standard for nitrogen oxides (NOX). (a) Except as provided under.../J heat input (0.30 lb/MMBtu) derived from liquid fossil fuel, liquid fossil fuel and wood...

  7. 40 CFR 60.55a - Standard for nitrogen oxides.

    Code of Federal Regulations, 2014 CFR

    2008-07-01

    ... 40 Protection of Environment 6 2008-07-01 2008-07-01 false Standard for nitrogen oxides. 60.55a... (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Municipal Waste... § 60.55a Standard for nitrogen oxides. On and after the date on which the initial compliance test...

  8. 40 CFR 90.318 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., and calibration test procedures specified in 40 CFR part 1065, subpart D, may be used in lieu of the... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Oxides of nitrogen analyzer... Emission Test Equipment Provisions § 90.318 Oxides of nitrogen analyzer calibration. (a) Calibrate...

  9. 40 CFR 89.321 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... periodic interference, system check, and calibration test procedures specified in 40 CFR part 1065 may be... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Oxides of nitrogen analyzer... Test Equipment Provisions § 89.321 Oxides of nitrogen analyzer calibration. (a) The...

  10. 40 CFR 90.318 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., and calibration test procedures specified in 40 CFR part 1065, subpart D, may be used in lieu of the... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Oxides of nitrogen analyzer... Emission Test Equipment Provisions § 90.318 Oxides of nitrogen analyzer calibration. (a) Calibrate...

  11. 40 CFR 90.318 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., and calibration test procedures specified in 40 CFR part 1065, subpart D, may be used in lieu of the... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Oxides of nitrogen analyzer calibration... Emission Test Equipment Provisions § 90.318 Oxides of nitrogen analyzer calibration. (a) Calibrate...

  12. 40 CFR 89.321 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... periodic interference, system check, and calibration test procedures specified in 40 CFR part 1065 may be... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Oxides of nitrogen analyzer... Test Equipment Provisions § 89.321 Oxides of nitrogen analyzer calibration. (a) The...

  13. 40 CFR 89.321 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... periodic interference, system check, and calibration test procedures specified in 40 CFR part 1065 may be... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Oxides of nitrogen analyzer... Test Equipment Provisions § 89.321 Oxides of nitrogen analyzer calibration. (a) The...

  14. 40 CFR 90.318 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., and calibration test procedures specified in 40 CFR part 1065, subpart D, may be used in lieu of the... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Oxides of nitrogen analyzer... Emission Test Equipment Provisions § 90.318 Oxides of nitrogen analyzer calibration. (a) Calibrate...

  15. 40 CFR 90.318 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., and calibration test procedures specified in 40 CFR part 1065, subpart D, may be used in lieu of the... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Oxides of nitrogen analyzer... Emission Test Equipment Provisions § 90.318 Oxides of nitrogen analyzer calibration. (a) Calibrate...

  16. 40 CFR 89.321 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... periodic interference, system check, and calibration test procedures specified in 40 CFR part 1065 may be... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Oxides of nitrogen analyzer... Test Equipment Provisions § 89.321 Oxides of nitrogen analyzer calibration. (a) The...

  17. 40 CFR 89.321 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... periodic interference, system check, and calibration test procedures specified in 40 CFR part 1065 may be... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Oxides of nitrogen analyzer calibration... Test Equipment Provisions § 89.321 Oxides of nitrogen analyzer calibration. (a) The...

  18. Variable oxygen/nitrogen enriched intake air system for internal combustion engine applications

    DOEpatents

    Poola, Ramesh B.; Sekar, Ramanujam R.; Cole, Roger L.

    1997-01-01

    An air supply control system for selectively supplying ambient air, oxygen enriched air and nitrogen enriched air to an intake of an internal combustion engine includes an air mixing chamber that is in fluid communication with the air intake. At least a portion of the ambient air flowing to the mixing chamber is selectively diverted through a secondary path that includes a selectively permeable air separating membrane device due a differential pressure established across the air separating membrane. The permeable membrane device separates a portion of the nitrogen in the ambient air so that oxygen enriched air (permeate) and nitrogen enriched air (retentate) are produced. The oxygen enriched air and the nitrogen enriched air can be selectively supplied to the mixing chamber or expelled to atmosphere. Alternatively, a portion of the nitrogen enriched air can be supplied through another control valve to a monatomic-nitrogen plasma generator device so that atomic nitrogen produced from the nitrogen enriched air can be then injected into the exhaust of the engine. The oxygen enriched air or the nitrogen enriched air becomes mixed with the ambient air in the mixing chamber and then the mixed air is supplied to the intake of the engine. As a result, the air being supplied to the intake of the engine can be regulated with respect to the concentration of oxygen and/or nitrogen.

  19. Chlorine activation indoors and outdoors via surface-mediated reactions of nitrogen oxides with hydrogen chloride

    PubMed Central

    Raff, Jonathan D.; Njegic, Bosiljka; Chang, Wayne L.; Gordon, Mark S.; Dabdub, Donald; Gerber, R. Benny; Finlayson-Pitts, Barbara J.

    2009-01-01

    Gaseous HCl generated from a variety of sources is ubiquitous in both outdoor and indoor air. Oxides of nitrogen (NOy) are also globally distributed, because NO formed in combustion processes is oxidized to NO2, HNO3, N2O5 and a variety of other nitrogen oxides during transport. Deposition of HCl and NOy onto surfaces is commonly regarded as providing permanent removal mechanisms. However, we show here a new surface-mediated coupling of nitrogen oxide and halogen activation cycles in which uptake of gaseous NO2 or N2O5 on solid substrates generates adsorbed intermediates that react with HCl to generate gaseous nitrosyl chloride (ClNO) and nitryl chloride (ClNO2), respectively. These are potentially harmful gases that photolyze to form highly reactive chlorine atoms. The reactions are shown both experimentally and theoretically to be enhanced by water, a surprising result given the availability of competing hydrolysis reaction pathways. Airshed modeling incorporating HCl generated from sea salt shows that in coastal urban regions, this heterogeneous chemistry increases surface-level ozone, a criteria air pollutant, greenhouse gas and source of atmospheric oxidants. In addition, it may contribute to recently measured high levels of ClNO2 in the polluted coastal marine boundary layer. This work also suggests the potential for chlorine atom chemistry to occur indoors where significant concentrations of oxides of nitrogen and HCl coexist. PMID:19620710

  20. Absorption and Oxidation of Nitrogen Oxide in Ionic Liquids.

    PubMed

    Kunov-Kruse, Andreas J; Thomassen, Peter L; Riisager, Anders; Mossin, Susanne; Fehrmann, Rasmus

    2016-08-01

    A new strategy for capturing nitrogen oxide, NO, from the gas phase is presented. Dilute NO gas is removed from the gas phase by ionic liquids under ambient conditions. The nitrate anion of the ionic liquid catalyzes the oxidation of NO to nitric acid by atmospheric oxygen in the presence of water. The nitric acid is absorbed in the ionic liquid up to approximately one mole HNO3 per mole of the ionic liquid due to the formation of hydrogen bonds. The nitric acid can be desorbed by heating, thereby regenerating the ionic liquid with excellent reproducibility. Here, time-resolved in-situ spectroscopic investigations of the reaction and products are presented. The procedure reveals a new vision for removing the pollutant NO by absorption into a non-volatile liquid and converting it into a useful bulk chemical, that is, HNO3 . PMID:27384885

  1. 180 MW demonstration of advanced tangentially-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. Technical progress report second quarter, 1991

    SciTech Connect

    Not Available

    1991-12-31

    ABB CE`s Low NOx Bulk Furnace Staging (LNBFS) System and Low NOx Concentric Firing System (LNCFS) are demonstrated in stepwise fashion. These systems incorporate the concept of advanced overfire air (AOFA), clustered coal nozzles, and offset air. A complete description of the installed technologies is provided in the following section. The primary objective of the Plant Lansing Smith demonstration is to determine the long-term effects of commercially available tangentially-fired low NOx combustion technologies on NOx emissions and boiler performance. Short-term tests of each technology are also being performed to provide engineering information about emissions and performance trends. A target of achieving fifty percent NOx reduction using combustion modifications has been established for the project.

  2. Emissions of oxides of nitrogen from an experimental premixed-hydrogen burner

    NASA Technical Reports Server (NTRS)

    Anderson, D. N.

    1976-01-01

    Flame-tube experiments using premixed hydrogen and air were conducted to determine the emissions of oxides of nitrogen (NOx) resulting from ultralean combustion. Measurements of NOx emissions and combustion efficiency were made for inlet mixture temperatures of 600 and 700 K, pressures of 3.8 x 10 to the 5th power and 5.2 x 10 to the 5th power N/m squared, reference velocities of 15 to 18 m/sec, and equivalence ratios of 0.2 to 0.4. At the 700 K inlet mixture temperature, NOx emissions were 0.06 ppmv, and combustion efficiency was 98 percent at an equivalence ratio of 0.24. The use of a high-blockage (92-percent blockage) flameholder made it possible to conduct tests without upstream burning in the premixing duct for mixtures with equivalence ratios less than 0.4. For richer mixtures upstream burning did occur and prevented further testing.

  3. Combustion and NO emission of high nitrogen content biomass in a pilot-scale vortexing fluidized bed combustor.

    PubMed

    Qian, F P; Chyang, C S; Huang, K S; Tso, Jim

    2011-01-01

    The combustion of biomass of various nitrogen contents and its NO emission were investigated experimentally in this study. All the experiments were conducted in an I.D. 0.45 m pilot-scale vortexing fluidized bed combustor (VFBC). Rice husk, corn, and soybean were used as feeding materials. Urea was added into the feeding materials for the purpose of adjusting nitrogen content. The effects of various operating parameters on NO emission, such as bed temperature, excess air ratio, and flow rate of secondary air, were investigated. The effects of nitrogen content of fuels on NO emissions were also investigated by using the mixtures of rice husk/soybean, rice husk/urea, corn/soybean, and corn/urea in various weight ratios. The NO concentrations at various positions in the combustor were sampled and recorded. The experimental results show that most nitric oxide is formed at just above the bed surface. Temperature and excess air ratio are the major operating parameters for NO emission. For biomass with high nitrogen content, NO emission decreases with excess air, and increases with bed temperature. Compared with char-N, volatile-N is the more dominant reactant source for NO emission. PMID:20800476

  4. Reaction behavior of trace oxygen during combustion of falling FeSi75 powder in a nitrogen flow

    NASA Astrophysics Data System (ADS)

    Li, Bin; Chen, Jun-hong; Jiang, Peng; Yan, Ming-wei; Sun, Jia-lin; Li, Yong

    2016-08-01

    To explore the reaction behavior of trace oxygen during the flash combustion process of falling FeSi75 powder in a nitrogen flow, a flash-combustion-synthesized Fe-Si3N4 sample was heat-treated to remove SiO2. The samples before and after the treatment were investigated by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy, and the formation mechanism of SiO2 was investigated. The results show that SiO2 in the Fe-Si3N4 is mainly located on the surface or around the Si3N4 particles in dense areas, existing in both crystalline and amorphous states; when the FeSi75 particles, which are less than 0.074 mm in size, fell in up-flowing hot N2 stream, trace oxygen in the N2 stream did not significantly hinder the nitridation of FeSi75 particles as it was consumed by the surface oxidation of the generated Si3N4 particles to form SiO2. At the reaction zone, the oxidation of Si3N4 particles decreased the oxygen partial pressure in the N2 stream and greatly reduced the opportunity for FeSi75 particles to be oxidized into SiO2; by virtue of the SiO2 film developed on the surface, the Si3N4 particles adhered to each other and formed dense areas in the material.

  5. Innovative Clean Coal Technology (ICCT): 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. Technical progress report: First quarter 1993

    SciTech Connect

    Not Available

    1993-12-31

    This quarterly report discusses the technical progress of an Innovative Clean Coal Technology (ICCT) demonstration being conducted at Georgia Power Company`s Plant Hammond Unit 4 located near Rome, Georgia. The primary goal of this project is the characterization of the low NO{sub x} combustion equipment through the collection and analysis of long-term emissions data. A target of achieving fifty percent NO{sub x} reduction using combustion modifications has been established for the project. The project provides a stepwise retrofit of an advanced overfire air (AOFA) system followed by low NO{sub x} burners (LNB). During each test phase of the project, diagnostic, performance, long-term, and verification testing will be performed. These tests are used to quantify the NO{sub x} reductions of each technology and evaluate the effects of those reductions on other combustion parameters such as particulate characteristics and boiler efficiency. During this quarter, long-term testing of the LNB + AOFA configuration continued and no parametric testing was performed. Further full-load optimization of the LNB + AOFA system began on March 30, 1993. Following completion of this optimization, comprehensive testing in this configuration will be performed including diagnostic, performance, verification, long-term, and chemical emissions testing. These tests are scheduled to start in May 1993 and continue through August 1993. Preliminary engineering and procurement are progressing on the Advanced Low NOx Digital Controls scope addition to the wall-fired project. The primary activities during this quarter include (1) refinement of the input/output lists, (2) procurement of the distributed digital control system, (3) configuration training, and (4) revision of schedule to accommodate project approval cycle and change in unit outage dates.

  6. Design, analysis, and fabrication of oxide-coated iridium/rhenium combustion chambers

    NASA Technical Reports Server (NTRS)

    Jang, Q.; Tuffias, R. H.; Laferla, R.; Ghoniem, N. M.

    1993-01-01

    Iridium-coated rhenium (Ir/Re) combustion chambers provide high temperature, oxidation-resistant operation for radiation-cooled liquid-fueled rocket engines. A 22-N (5-lb(sub f)) chamber has been operated for 15 hours at 2200 C (4000 F) using nitrogen tetroxide/monomethyl hydrazine (NTO/MMH) propellant, with negligible internal erosion. The oxidation resistance of these chambers could be further increased by the addition of refractory oxide coatings, providing longer life and/or operation in more oxidizing and higher temperature environments. The oxide coatings would serve as a thermal and diffusion barrier for the iridium coating, lowering the temperature of the iridium layer while also preventing the ingress of oxygen and egress of iridium oxides. This would serve to slow the failure mechanisms of Ir/Re chambers, namely the diffusion of rhenium to the inner surface and the oxidation of iridium. Such protection could extend chamber lifetimes by tens or perhaps hundreds of hours, and allow chamber operation on stoichiometric or higher mixture ratio oxygen/hydrogen (O2/H2) propellant. Extensive thermomechanical, thermochemical, and mass transport modeling was performed as a key material/structure design tool. Based on the results of these analyses, several 22-N oxide-coated Ir/Re chambers were fabricated and delivered to NASA Lewis Research Center for hot-fire testing.

  7. Design, analysis, and fabrication of oxide-coated iridium/rhenium combustion chambers

    NASA Astrophysics Data System (ADS)

    Jang, Q.; Tuffias, R. H.; Laferla, R.; Ghoniem, N. M.

    1993-11-01

    Iridium-coated rhenium (Ir/Re) combustion chambers provide high temperature, oxidation-resistant operation for radiation-cooled liquid-fueled rocket engines. A 22-N (5-lb(sub f)) chamber has been operated for 15 hours at 2200 C (4000 F) using nitrogen tetroxide/monomethyl hydrazine (NTO/MMH) propellant, with negligible internal erosion. The oxidation resistance of these chambers could be further increased by the addition of refractory oxide coatings, providing longer life and/or operation in more oxidizing and higher temperature environments. The oxide coatings would serve as a thermal and diffusion barrier for the iridium coating, lowering the temperature of the iridium layer while also preventing the ingress of oxygen and egress of iridium oxides. This would serve to slow the failure mechanisms of Ir/Re chambers, namely the diffusion of rhenium to the inner surface and the oxidation of iridium. Such protection could extend chamber lifetimes by tens or perhaps hundreds of hours, and allow chamber operation on stoichiometric or higher mixture ratio oxygen/hydrogen (O2/H2) propellant. Extensive thermomechanical, thermochemical, and mass transport modeling was performed as a key material/structure design tool. Based on the results of these analyses, several 22-N oxide-coated Ir/Re chambers were fabricated and delivered to NASA Lewis Research Center for hot-fire testing.

  8. Nitrogen oxides and methane treatment by non-thermal plasma

    NASA Astrophysics Data System (ADS)

    Alva, E.; Pacheco, M.; Colín, A.; Sánchez, V.; Pacheco, J.; Valdivia, R.; Soria, G.

    2015-03-01

    Non thermal plasma was used to treat nitrogen oxides (NOx) and methane (CH4), since they are important constituents of hydrocarbon combustion emissions processes and, both gases, play a key role in the formation of tropospheric ozone. These gases are involved in environmental problems like acid rain and some diseases such as bronchitis and pneumonia. In the case of methane is widely known its importance in the global climate change, and currently accounts for 30% of global warming. There is a growing concern for methane leaks, associated with a rapid expansion of unconventional oil and gas extraction techniques as well as a large-scale methane release from Arctic because of ice melting and the subsequent methane production of decaying organic matter. Therefore, methane mitigation is a key to avoid dangerous levels of global warming. The research, here reported, deals about the generation of non-thermal plasma with a double dielectric barrier (2DBD) at atmospheric pressure with alternating current (AC) for NOx and CH4 treatment. The degradation efficiencies and their respective power consumption for different reactor configurations (cylindrical and planar) are also reported. Qualitative and quantitative analysis of gases degradation are reported before and after treatment with cold plasma. Experimental and theoretical results are compared obtaining good removal efficiencies, superior to 90% and to 20% respectively for NOx and CH4.

  9. Combustion synthesis of oxide-carbide composites

    SciTech Connect

    Wang, L.L.; Munir, Z.A. . Div. of Materials Science and Engineering)

    1990-02-01

    Synthesis of an oxide-carbide composite material through a self- propagating reaction process can be achieved by coupling a highly exothermic thermite reaction and a weakly exothermic carbide reaction. Two systems, one with Al and the other with Mg as the reducing agent in the presence of B{sub 2}O{sub 3} and carbon, are used as the reaction models for this investigation. Based on the experimental results, the formation Al{sub 2}O{sub 3}-B{sub 4}C and MgO-N{sub 4}C composites is proposed to involve a two-step sequential reaction mechanism. The highly exothermic thermite reaction between the reducing agent and B{sub 2}O{sub 3} occurs first, and the heat generated subsequently brings about the formation of B{sub 4}C between the liberated boron and the carbon. The exothermic reaction between Al and B{sub 2}O{sub 3} is initiated at about 850{degrees}C. In the reaction between Mg and B{sub 2}O{sub 3}, however, the interaction between Mg and B{sub 2}O{sub 3} depends on the surrounding inert gas pressure due to the high volatility of Mg. The interaction changes from one involving gaseous Mg and liquid B{sub 2}O{sub 3} to one involving liquid Mg and liquid B{sub 2}O{sub 3} as the pressure increases. In both systems, reactions between the metallic oxides (i.e. Al{sub 2}O{sub 3} or MgO) and B{sub 2}O{sub 3} compete with the thermite reaction. Although it is possible to synthesize B{sub 4}C from carbon fibers in the 6Mg+B{sub 2+}O{sub 3}+C system, the carbon fiber is only partially converted, and the carbide formed is loosely attached to the unreacted carbon core. 17 refs., 23 figs., 3 tabs.

  10. Reduction of Nitrogen Oxides Emissions from a Coal-Fired Boiler Unit

    NASA Astrophysics Data System (ADS)

    Zhuikov, Andrey V.; Feoktistov, Dmitry V.; Koshurnikova, Natalya N.; Zlenko, Lyudmila V.

    2016-02-01

    During combustion of fossil fuels a large amount of harmful substances are discharged into the atmospheres of cities by industrial heating boiler houses. The most harmful substances among them are nitrogen oxides. The paper presents one of the most effective technological solutions for suppressing nitrogen oxides; it is arrangement of circulation process with additional mounting of the nozzle directed into the bottom of the ash hopper. When brown high-moisture coals are burnt in the medium power boilers, generally fuel nitrogen oxides are produced. It is possible to reduce their production by two ways: lowering the temperature in the core of the torch or decreasing the excess-air factor in the boiler furnace. Proposed solution includes the arrangement of burning process with additional nozzle installed in the lower part of the ash hopper. Air supply from these nozzles creates vortex involving large unburned fuel particles in multiple circulations. Thereby time of their staying in the combustion zone is prolonging. The findings describe the results of the proposed solution; and recommendations for the use of this technological method are given for other boilers.

  11. METHOD OF FIXING NITROGEN FOR PRODUCING OXIDES OF NITROGEN

    DOEpatents

    Harteck, P.; Dondes, S.

    1959-08-01

    A method is described for fixing nitrogen from air by compressing the air, irradiating the compressed air in a nuclear reactor, cooling to remove NO/ sub 2/, compressing the cooled gas, further cooling to remove N/sub 2/O and recirculating the cooled compressed air to the reactor.

  12. 75 FR 20595 - Review of the Secondary National Ambient Air Quality Standards for Oxides of Nitrogen and Oxides...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-20

    ... for Oxides of Nitrogen and Oxides of Sulfur: First External Review Draft (75 FR 11877; March 12, 2010... AGENCY Review of the Secondary National Ambient Air Quality Standards for Oxides of Nitrogen and Oxides... a proposal addressing the nitrogen oxides (NO X ) and sulfur oxides (SO X ) secondary...

  13. 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal fired boilers. Second quarterly technical progress report, [April--June 1993

    SciTech Connect

    Not Available

    1993-12-31

    The primary goal of this project is the characterization of the low NO{sub x} combustion equipment through the collection and analysis of long-term emissions data. A target of achieving fifty percent NO{sub x} reduction using combustion modifications has been established for the project. The project provides a stepwise retrofit of an advanced overfire air (AOFA) system followed by low NO{sub x} burners (LNB). During each test phase of the project, diagnostic, performance, long-term and verification testing will be performed. These tests are used to quantify the NO{sub x} reductions of each technology and evaluate the effects of those reductions on other combustion parameters such as particulate characteristics and boiler efficiency. Baseline, AOFA, and LNB without AOFA test segments have been completed. Analysis of the 94 days of LNB long-term data collected show the full-load NO{sub x} emission levels to be approximately 0.65 lb/MBtu with flyash LOI values of approximately 8 percent. Corresponding values for the AOFA configuration are 0.94 lb/MBtu and approximately 10 percent. For comparison, the long-term full-load, baseline NO{sub x} emission level was approximately 1.24 lb/MBtu at 5.2 percent LOI. Comprehensive testing of the LNB plus AOFA configuration began in May 1993 and is scheduled to end during August 1993. As of June 30, the diagnostic, performance, chemical emissions tests segments for this configuration have been conducted and 29 days of long-term, emissions data collected. Preliminary results from the May--June 1993 tests of the LNB plus AOFA system show that the full load NO{sub x} emissions are approximately 0.42 lb/MBtu with corresponding fly ash LOI values near 8 percent. This is a substantial improvement in both NO{sub x} emissions and LOI values when compared to the results obtained during the February--March 1992 abbreviated testing of this system.

  14. Innovative Clean Coal Technology (ICCT): 180 MW demonstration of advanced tangentially-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. Phase 1, Baseline tests

    SciTech Connect

    Not Available

    1992-01-01

    The primary objective of the project is to investigate the long-term effects of commercially available tangentially-fired low NO{sub x} combustion technologies on NOx emissions and boiler performance on Unit 2 at Gulf Power Company`s Plant Lansing Smith located near Lynn Haven, Florida. The project will characterize emissions and performance of a tangentially-fired boiler operating in the following configurations: Baseline ``as-found`` configuration: Phase 1; retrofitted low NO{sub x} concentric firing system (LNCFS) Level 2 and simulated low NO{sub x} bulk furnace staging (LNBFS): Phase 2; retrofitted low NO{sub x} concentric firing system (LNCFS) Level 3, Phase 3a and simulated LNCFS Level 1, Phase 3b.

  15. Innovative Clean Coal Technology (ICCT): 180 MW demonstration of advanced tangentially-fired combustion techniques for the reduction of nitrogen oxide (NO sub x ) emissions from coal-fired boilers

    SciTech Connect

    Not Available

    1992-01-01

    The primary objective of the project is to investigate the long-term effects of commercially available tangentially-fired low NO{sub x} combustion technologies on NOx emissions and boiler performance on Unit 2 at Gulf Power Company's Plant Lansing Smith located near Lynn Haven, Florida. The project will characterize emissions and performance of a tangentially-fired boiler operating in the following configurations: Baseline as-found'' configuration: Phase 1; retrofitted low NO{sub x} concentric firing system (LNCFS) Level 2 and simulated low NO{sub x} bulk furnace staging (LNBFS): Phase 2; retrofitted low NO{sub x} concentric firing system (LNCFS) Level 3, Phase 3a and simulated LNCFS Level 1, Phase 3b.

  16. 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NOx) emissions from coal-fired boilers. Public design report (preliminary and final)

    SciTech Connect

    1996-07-01

    This Public Design Report presents the design criteria of a DOE Innovative Clean Coal Technology (ICCT) project demonstrating advanced wall-fired combustion techniques for the reduction of NO{sub x} emissions from coal-fired boilers. The project is being conducted at Georgia Power Company`s Plant Hammond Unit 4 (500 MW) near Rome, Georgia. The technologies being demonstrated at this site include Foster Wheeler Energy Corporation`s advanced overfire air system and Controlled Flow/Split Flame low NO{sub x} burner. This report provides documentation on the design criteria used in the performance of this project as it pertains to the scope involved with the low NO{sub x} burners, advanced overfire systems, and digital control system.

  17. Emission control system for nitrogen oxides using enhanced oxidation, scrubbing, and biofiltration

    SciTech Connect

    Martinez, A.; Cabezas, J.

    2009-05-15

    Nitric oxide (NO) constitutes about 90% of the nitrogen oxide (NOx) species in the flue gases emitted from combustion processes, but NO is difficult to remove in existing scrubbers due to its low solubility. NO may be oxidized with hydrogen peroxide (H{sub 2}O{sub 2}) into soluble species that can be partially removed in wet scrubbers simultaneously with sulfur dioxide (SO{sub 2}) and biofilters located downstream of the scrubber can increase the removal efficiency. This article presents the results of a bench-scale evaluation of such an integrated system combining enhanced oxidation, scrubbing, and biofiltration. Main components of the bench-scale system consisted of a quartz tube in a furnace to simulate the NO oxidation stage and two vertical packed bed cylinders constituting the scrubber and the biofilter. Inlet synthetic gas had a concentration of 50 mu L/L of NO. Overall removal efficiency by the integrated system was in the range of 53% to 93% with an average of 79%, absorption accounted for 43% and biofiltration for 36% of the total removal. Key parameters in the operation of the system are the H{sub 2}O{sub 2}:NO mole ratio, the reaction temperature, the liquid to gas flow ratio, and the biofilter residence time. Experimental results suggest a path for optimization of the technology focusing simultaneously in minimizing H{sub 2}O{sub 2} use in the enhanced oxidation stage, reducing water consumption in the scrubber stage and balancing the residence times in the three stages of the integrated system.

  18. 91. VIEW OF OXYGEN AND GASEOUS NITROGEN TANKS AND OXIDIZER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    91. VIEW OF OXYGEN AND GASEOUS NITROGEN TANKS AND OXIDIZER APRON FROM NORTH - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  19. TECHNOLOGY INNOVATIONS AND EXPERIENCE CURVES FOR NITROGEN OXIDES CONTROL TECHNOLOGIES

    EPA Science Inventory

    This paper reviews the regulatory history for nitrogen oxides (NOX) pollutant emissions from stationary sources, primarily in coal-fired power plants. Nitrogen dioxide (NO2) is one of the six criteria pollutants regulated by the 1970 Clean Air Act where Nati...

  20. 40 CFR 52.65 - Control Strategy: Nitrogen oxides.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 3 2013-07-01 2013-07-01 false Control Strategy: Nitrogen oxides. 52... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Alabama § 52.65 Control Strategy: Nitrogen... using to implement provisions of the Prevention of Significant Deterioration regulations for...

  1. 40 CFR 52.65 - Control Strategy: Nitrogen oxides.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 3 2014-07-01 2014-07-01 false Control Strategy: Nitrogen oxides. 52... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Alabama § 52.65 Control Strategy: Nitrogen... using to implement provisions of the Prevention of Significant Deterioration regulations for...

  2. 40 CFR 52.65 - Control Strategy: Nitrogen oxides.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 3 2012-07-01 2012-07-01 false Control Strategy: Nitrogen oxides. 52... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Alabama § 52.65 Control Strategy: Nitrogen... using to implement provisions of the Prevention of Significant Deterioration regulations for...

  3. 40 CFR 60.332 - Standard for nitrogen oxides.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standard for nitrogen oxides. 60.332 Section 60.332 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Stationary Gas Turbines § 60.332 Standard for nitrogen...

  4. Nitrogen oxides reduction by carbonaceous materials and carbon dioxide separation using regenerative metal oxides from fossil fuel based flue gas

    NASA Astrophysics Data System (ADS)

    Gupta, Himanshu

    The ever-growing energy demands due to rising global population and continuing lifestyle improvements has placed indispensable emphasis on fossil fuels. Combustion of fossil fuels leads to the emission of harmful gaseous pollutants such as oxides of sulfur (SOx) and nitrogen (NOx), carbon dioxide (CO2), mercury, particulate matter, etc. Documented evidence has proved that this air pollution leads to adverse environmental health. This dissertation focuses on the development of technologies for the control of NOx and CO2 emissions. The first part of the thesis (Chapters 2--6) deals with the development of carbon based post combustion NOx reduction technology called CARBONOX process. High temperature combustion oxidizes both atmospheric nitrogen and organic nitrogen in coal to nitric oxide (NO). The reaction rate between graphite and NO is slow and requires high temperature (>900°C). The presence of metallic species in coal char catalyzes the reaction. The reaction temperature is lowered in the presence of oxygen to about 600--850°C. Chemical impregnation, specifically sodium compounds, further lowers the reaction temperature to 350--600°C. Activated high sodium lignite char (HSLC) provided the best performance for NO reduction. The requirement of char for NOx reduction is about 8--12 g carbon/g NO reduced in the presence of 2% oxygen in the inlet gas. The second part of this dissertation (chapter 7--8) focuses on the development of a reaction-based process for the separation of CO2 from combustion flue gas. Certain metal oxides react with CO2 forming metal carbonates under flue gas conditions. They can be calcined separately to yield CO2. Calcium oxide (CaO) has been identified as a viable metal oxide for the carbonation-calcination reaction (CCR) scheme. CaO synthesized from naturally occurring precursors (limestone and dolomite) attained 45--55% of their stoichiometric conversion due to the susceptibility of their microporous structure. High surface area

  5. Effect of premixing quality on oxides of nitrogen in gas turbine combustors foi HC

    NASA Technical Reports Server (NTRS)

    Roffe, G.; Ferri, A.

    1976-01-01

    Experiments were conducted to determine the effectiveness of several premixing prevaporizing gas turbine combustor designs in reducing formation of oxides of nitrogen at the supersonic cruise condition. An atomized spray from a single injector mounted on the axis of the mixer tube produced a high initial concentration of fuel near the axis and only moderate premixed conditions entering the combustor. A fuel spray produced by 12 flush-mounted normal injection orifices in the mixer tube wall produced a good initial despersion of fuel and resulted in nearly complete premixing. Oxides of nitrogen emission levels of the order of 0.2 g NO2/kg fuel were obtained at 99 percent combustion efficiency at an equivalence ratio of 0.4. Overall total pressure drop was less than 3 percent through the 1-meter combustor module.

  6. Oxidation of Mercury in Products of Coal Combustion

    SciTech Connect

    Peter Walsh; Giang Tong; Neeles Bhopatkar; Thomas Gale; George Blankenship; Conrad Ingram; Selasi Blavo Tesfamariam Mehreteab; Victor Banjoko; Yohannes Ghirmazion; Heng Ban; April Sibley

    2009-09-14

    Laboratory measurements of mercury oxidation during selective catalytic reduction (SCR) of nitric oxide, simulation of pilot-scale measurements of mercury oxidation and adsorption by unburned carbon and fly ash, and synthesis of new materials for simultaneous oxidation and adsorption of mercury, were performed in support of the development of technology for control of mercury emissions from coal-fired boilers and furnaces. Conversion of gas-phase mercury from the elemental state to water-soluble oxidized form (HgCl{sub 2}) enables removal of mercury during wet flue gas desulfurization. The increase in mercury oxidation in a monolithic V{sub 2}O{sub 5}-WO{sub 3}/TiO{sub 2} SCR catalyst with increasing HCl at low levels of HCl (< 10 ppmv) and decrease in mercury oxidation with increasing NH{sub 3}/NO ratio during SCR were consistent with results of previous work by others. The most significant finding of the present work was the inhibition of mercury oxidation in the presence of CO during SCR of NO at low levels of HCl. In the presence of 2 ppmv HCl, expected in combustion products from some Powder River Basin coals, an increase in CO from 0 to 50 ppmv reduced the extent of mercury oxidation from 24 {+-} 3 to 1 {+-} 4%. Further increase in CO to 100 ppmv completely suppressed mercury oxidation. In the presence of 11-12 ppmv HCl, increasing CO from 0 to {approx}120 ppmv reduced mercury oxidation from {approx}70% to 50%. Conversion of SO{sub 2} to sulfate also decreased with increasing NH{sub 3}/NO ratio, but the effects of HCl and CO in flue gas on SO{sub 2} oxidation were unclear. Oxidation and adsorption of mercury by unburned carbon and fly ash enables mercury removal in a particulate control device. A chemical kinetic mechanism consisting of nine homogeneous and heterogeneous reactions for mercury oxidation and removal was developed to interpret pilot-scale measurements of mercury oxidation and adsorption by unburned carbon and fly ash in experiments at pilot

  7. PROCEEDINGS OF THE STATIONARY SOURCE COMBUSTION SYMPOSIUM (3RD). VOLUME IV. FUNDAMENTAL COMBUSTION RESEARCH AND ENVIRONMENTAL ASSESSMENT

    EPA Science Inventory

    ;Contents: Fundamental combustion research--(NOx abatement in fossil fuel combustion--chemical kinetic considerations, Heterogeneous processes involved in the control of nitrogen oxide formation in fossil fuel flames, Transport processes and numerical model development--FCR progr...

  8. 40 CFR 86.318-79 - Oxides of nitrogen analyzer specifications.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 19 2013-07-01 2013-07-01 false Oxides of nitrogen analyzer... Procedures § 86.318-79 Oxides of nitrogen analyzer specifications. (a) Oxides of nitrogen are to be measured....327. (b) Option. The oxides of nitrogen may be measured with an NDIR analyzer system that meets...

  9. 40 CFR 86.318-79 - Oxides of nitrogen analyzer specifications.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 18 2011-07-01 2011-07-01 false Oxides of nitrogen analyzer... Procedures § 86.318-79 Oxides of nitrogen analyzer specifications. (a) Oxides of nitrogen are to be measured....327. (b) Option. The oxides of nitrogen may be measured with an NDIR analyzer system that meets...

  10. 40 CFR 86.318-79 - Oxides of nitrogen analyzer specifications.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Oxides of nitrogen analyzer... Procedures § 86.318-79 Oxides of nitrogen analyzer specifications. (a) Oxides of nitrogen are to be measured....327. (b) Option. The oxides of nitrogen may be measured with an NDIR analyzer system that meets...

  11. 40 CFR 86.318-79 - Oxides of nitrogen analyzer specifications.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 19 2012-07-01 2012-07-01 false Oxides of nitrogen analyzer... Procedures § 86.318-79 Oxides of nitrogen analyzer specifications. (a) Oxides of nitrogen are to be measured....327. (b) Option. The oxides of nitrogen may be measured with an NDIR analyzer system that meets...

  12. Laccase oxidation and removal of toxicants released during combustion processes.

    PubMed

    Prasetyo, Endry Nugroho; Semlitsch, Stefan; Nyanhongo, Gibson S; Lemmouchi, Yahia; Guebitz, Georg M

    2016-02-01

    This study reports for the first time the ability of laccases adsorbed on cellulose acetate to eliminate toxicants released during combustion processes. Laccases directly oxidized and eliminated more than 40% w/v of 14 mM of 1,4-dihydroxybenzene (hydroquinone); 2-methyl-1,4-benzenediol (methylhydroquinone); 1,4-dihydroxy-2,3,5-trimethylbenzene (trimethylhydroquinone); 3-methylphenol (m-cresol); 4-methylphenol (p-cresol); 2-methylphenol (o-cresol); 1,3-benzenediol (resorcinol); 1,2-dihydroxybenzene (catechol); 3,4-dihydroxytoluene (4-methylcatechol) and 2-naphthylamine. Further, laccase oxidized 2-naphthylamine, hydroquinone, catechol, methylhydroquinone and methylcatechol were also able to in turn mediate the elimination of >90% w/v of toxicants which are per-se non-laccase substrates such as 3-aminobiphenyl; 4-aminobiphenyl; benz[a]anthracene; 3-(1-nitrosopyrrolidin-2-yl) pyridine (NNN); formaldehyde; 4-(methyl-nitrosamino-1-(3-pyridyl)-1-butanone (NNK); 2-butenal (crotonaldehyde); nitric oxide and vinyl cyanide (acrylonitrile). These studies demonstrate the potential of laccase immobilized on solid supports to remove many structurally different toxicants released during combustion processes. This system has great potential application for in situ removal of toxicants in the manufacturing, food processing and food service industries. PMID:26408262

  13. Catalytic reduction of nitrogen oxides from waste gases. (Latest citations from the US Patent bibliographic file with exemplary claims). Published Search

    SciTech Connect

    1996-12-01

    The bibliography contains citations of selected patents concerning catalytic reduction of nitrogen oxides from waste gases. Preparation, properties, and regeneration of catalysts used to reduce nitrogen oxides are discussed. Topics also include cleanup and reduction technologies for flue gas; automotive exhaust gas; and air pollutants resulting from fluidized bed combustion, incinerators, and other waste gas producing systems. Citations of selected foreign patents concerning nitrogen oxide reduction are examined in a related bibliography. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  14. Catalytic reduction of nitrogen oxides from waste gases. (Latest citations from the US Patent bibliographic file with exemplary claims). Published Search

    SciTech Connect

    1995-12-01

    The bibliography contains citations of selected patents concerning catalytic reduction of nitrogen oxides from waste gases. Preparation, properties, and regeneration of catalysts used to reduce nitrogen oxides are discussed. Topics also include cleanup and reduction technologies for flue gas; automotive exhaust gas; and air pollutants resulting from fluidized bed combustion, incinerators, and other waste gas producing systems. Citations of selected foreign patents concerning nitrogen oxide reduction are examined in a related bibliography. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  15. Role of OH-initiated oxidation of isoprene in aging of combustion soot.

    PubMed

    Khalizov, Alexei F; Lin, Yun; Qiu, Chong; Guo, Song; Collins, Don; Zhang, Renyi

    2013-03-01

    We have investigated the contribution of OH-initiated oxidation of isoprene to the atmospheric aging of combustion soot. The experiments were conducted in a fluoropolymer chamber on size-classified soot aerosols in the presence of isoprene, photolytically generated OH, and nitrogen oxides. The evolution in the mixing state of soot was monitored from simultaneous measurements of the particle size and mass, which were used to calculate the particle effective density, dynamic shape factor, mass fractal dimension, and coating thickness. When soot particles age, the increase in mass is accompanied by a decrease in particle mobility diameter and an increase in effective density. Coating material not only fills in void spaces, but also causes partial restructuring of fractal soot aggregates. For thinly coated aggregates, the single scattering albedo increases weakly because of the decreased light absorption and practically unchanged scattering. Upon humidification, coated particles absorb water, leading to an additional compaction. Aging transforms initially hydrophobic soot particles into efficient cloud condensation nuclei at a rate that increases in the presence of nitrogen oxides. Our results suggest that ubiquitous biogenic isoprene plays an important role in aging of anthropogenic soot, shortening its atmospheric lifetime and considerably altering its impacts on air quality and climate. PMID:23379649

  16. Preparation and Evaluation of Nitrogen Doped Tungsten Oxide Thin Films

    NASA Astrophysics Data System (ADS)

    Nakagawa, Koichi; Miura, Noboru; Matsumoto, Setsuko; Nakano, Ryotaro; Matsumoto, Hironaga

    Nitrogen doped tungsten oxide thin films were prepared by RF reactive sputtering in a gas mixture of argon, oxygen and nitrogen at room temperature. As a result of X-ray photoelectron spectroscopy, it was thought that the doped nitrogen in the films is bonding to tungsten of WO3 bonding states as anion and exits in substitution sites in WO3. The optical absorption edge was shifted to lower energy region with nitrogen doping. The nitrogen doped thin films exhibit a coloration to black from transparent yellow by electrochromism. Additionally, a new peak at 2.3 eV related to nitrogen doping is observed in the spectra of color center at bleaching process.

  17. 40 CFR 52.65 - Control Strategy: Nitrogen oxides.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... oxides. On October 22, 1990, the Alabama Department of Environmental Management submitted a revision to... 40 Protection of Environment 3 2011-07-01 2011-07-01 false Control Strategy: Nitrogen oxides. 52.65 Section 52.65 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR...

  18. 40 CFR 52.65 - Control Strategy: Nitrogen oxides.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... oxides. On October 22, 1990, the Alabama Department of Environmental Management submitted a revision to... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Control Strategy: Nitrogen oxides. 52.65 Section 52.65 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR...

  19. Process and Equipment for Nitrogen Oxide Waste Conversion to Fertilizer

    NASA Technical Reports Server (NTRS)

    Lueck, Dale E. (Inventor); Parrish, Clyde F. (Inventor)

    2000-01-01

    The present invention describes a process for converting vapor streams from sources containing at least one nitrogen-containing oxidizing agent therein to a liquid fertilizer composition comprising the steps of: (1) directing a vapor stream containing at least nitrogen-containing oxidizing agent to a first contact zone; (2) contacting said vapor stream with water to form nitrogen oxide(s) from said at least one nitrogen- containing oxidizing agent; (3) directing said acid(s) as a second stream to a second contact zone; (4) exposing said second stream to hydrogen peroxide which is present within said second contact zone in a relative amount of at least 0.1% by weight of said second stream within said second contact zone to convert at least some of any nitrogen oxide species or ions other than in the nitrite form present within said second stream to nitrate ion; (5) sampling said stream within said second contact zone to determine the relative amount of hydrogen peroxide within said second contact zone; (6) adding hydrogen peroxide to said second contact zone when a level on hydrogen peroxide less than 0.1% by weight in said second stream is determined by said sampling; (7) adding a solution comprising potassium hydroxide to said second stream to maintain a pH between 6.0 and 11.0 within said second stream within said second contact zone to form a solution of potassium nitrate; and (8) removing sais solution of potassium nitrate from said second contact zone.

  20. Pyrolysis and combustion of tobacco in a cigarette smoking simulator under air and nitrogen atmosphere.

    PubMed

    Busch, Christian; Streibel, Thorsten; Liu, Chuan; McAdam, Kevin G; Zimmermann, Ralf

    2012-04-01

    A coupling between a cigarette smoking simulator and a time-of-flight mass spectrometer was constructed to allow investigation of tobacco smoke formation under simulated burning conditions. The cigarette smoking simulator is designed to burn a sample in close approximation to the conditions experienced by a lit cigarette. The apparatus also permits conditions outside those of normal cigarette burning to be investigated for mechanistic understanding purposes. It allows control of parameters such as smouldering and puff temperatures, as well as combustion rate and puffing volume. In this study, the system enabled examination of the effects of "smoking" a cigarette under a nitrogen atmosphere. Time-of-flight mass spectrometry combined with a soft ionisation technique is expedient to analyse complex mixtures such as tobacco smoke with a high time resolution. The objective of the study was to separate pyrolysis from combustion processes to reveal the formation mechanism of several selected toxicants. A purposely designed adapter, with no measurable dead volume or memory effects, enables the analysis of pyrolysis and combustion gases from tobacco and tobacco products (e.g. 3R4F reference cigarette) with minimum aging. The combined system demonstrates clear distinctions between smoke composition found under air and nitrogen smoking atmospheres based on the corresponding mass spectra and visualisations using principal component analysis. PMID:22392377

  1. NITROGEN OXIDE GAS EMISSIONS FROM TEMPERATE FOREST SOILS RECEIVING LONG-TERM NITROGEN INPUTS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    From spring 2000 through fall 2001, we made monthly measurements of nitric oxide and nitrous oxide fluxes in two temperate forest sites in Massachusetts that have been treated since 1988 with different levels of nitrogen (N) to simulate elevated rates of atmospheric N deposition. Plots within a red ...

  2. Method of removing oxides of sulfur and oxides of nitrogen from exhaust gases

    SciTech Connect

    Walker, R.J.

    1986-10-07

    A method is described of removing oxides of sulfur and oxides of nitrogen from an exhaust gas, the method comprising: contacting the exhaust gas with a liquid absorbent including a metal chelate for oxide of nitrogen absorption and a solution of sulfite and bisulfite ions for oxide of sulfur absorption; regenerating the liquid absorbent capacity for oxide of sulfur gases by electrodialysis in a cell containing at least two bipolar membranes, an anion selective membrane and compartments bounded by the membranes; stripping oxides of nitrogen from the liquid absorbent into a gas flow to regenerate the capacity of the liquid absorbent for oxide of nitrogen gases; and recycling the regenerated liquid absorbent into contact with the exhaust gas.

  3. Method For Selective Catalytic Reduction Of Nitrogen Oxides

    DOEpatents

    Mowery-Evans, Deborah L.; Gardner, Timothy J.; McLaughlin, Linda I.

    2005-02-15

    A method for catalytically reducing nitrogen oxide compounds (NO.sub.x, defined as nitric oxide, NO, +nitrogen dioxide, NO.sub.2) in a gas by a material comprising a base metal consisting essentially of CuO and Mn, and oxides of Mn, on an activated metal hydrous metal oxide support, such as HMO:Si. A promoter, such as tungsten oxide or molybdenum oxide, can be added and has been shown to increase conversion efficiency. This method provides good conversion of NO.sub.x to N.sub.2, good selectivity, good durability, resistance to SO.sub.2 aging and low toxicity compared with methods utilizing vanadia-based catalysts.

  4. Method for selective catalytic reduction of nitrogen oxides

    DOEpatents

    Mowery-Evans, Deborah L.; Gardner, Timothy J.; McLaughlin, Linda I.

    2005-02-15

    A method for catalytically reducing nitrogen oxide compounds (NO.sub.x, defined as nitric oxide, NO, +nitrogen dioxide, NO.sub.2) in a gas by a material comprising a base metal consisting essentially of CuO and Mn, and oxides of Mn, on an activated metal hydrous metal oxide support, such as HMO:Si. A promoter, such as tungsten oxide or molybdenum oxide, can be added and has been shown to increase conversion efficiency. This method provides good conversion of NO.sub.x to N.sub.2, good selectivity, good durability, resistance to SO.sub.2 aging and low toxicity compared with methods utilizing vanadia-based catalysts.

  5. Low temperature combustion using nitrogen enrichment to mitigate NOx from large bore natural gas fueled engines.

    SciTech Connect

    Biruduganti, M.; Gupta, S.; Sekar, R.; Energy Systems

    2010-01-01

    Low temperature combustion is identified as one of the pathways to meet the mandatory ultra low NO{sub x} emissions levels set by the regulatory agencies. Exhaust gas recirculation (EGR) is a well known technique to realize low NO{sub x} emissions. However, EGR has many built-in adverse ramifications that negate its advantages in the long term. This paper discusses nitrogen enrichment of intake air using air separation membranes as a better alternative to the mature EGR technique. This investigation was undertaken to determine the maximum acceptable level of nitrogen enrichment of air for a single-cylinder spark-ignited natural gas engine. NO{sub x} reduction as high as 70% was realized with a modest 2% nitrogen enrichment while maintaining power density and simultaneously improving fuel conversion efficiency (FCE). Any enrichment beyond this level degraded engine performance in terms of power density, FCE, and unburned hydrocarbon emissions. The effect of ignition timing was also studied with and without N{sub 2} enrichment. Finally, lean burn versus stoichiometric operation utilizing nitrogen enrichment was compared. Analysis showed that lean burn operation along with nitrogen enrichment is one of the effective pathways for realizing better FCE and lower NO{sub x} emissions.

  6. Sintering of the reaction products of combustion of alloys in nitrogen

    SciTech Connect

    Maksimov, Y.M.; Raskolenko, L.G.; Zepakova, O.K.; Ziatdinov, M.K.

    1986-05-01

    An investigation of the mechanism of compacting of Fe-V alloy with a sigma-phase structure, a low porosity composite material consisting of alpha-iron and a filler of delta-vanadium nitride, is made after the synthesis surge. Alloys containing 50 wt.% Fe were prepared by sintering in a vacuum furnace of powders of type VEL-1 vandium and special purity carbonyl iron. The mechanism of compacting was studied on specimens in hardened water. Metallographic investigations were made on MIM-7 and PMT-3 instruments and the phase analysis on a DRON-2 instrument. Rapid compacting in combustion of sigma-FeV in nitrogen is determined by combining of the solid-liquid drops formed in the combustion front and consisting of molten iron and vanadium nitrides.

  7. Experimental study of effect of nitrogenous compounds in fuel on the emission of oxides of nitrogen from gas turbines

    SciTech Connect

    Svinukhov, V.P.; Filippova, E.M.

    1987-11-01

    Results of a study are presented on the relation between the output of nitric oxide and nitrogen dioxide in the exhaust gas of a gas turbine and the combined nitrogen content of the fuel to which organic nitrogen compounds, including piperidine, pyridine, and analine, have been added. The exhaust gases were analyzed continuously for nitric oxide, nitrogen dioxide, carbon monoxide, carbon dioxide, and unburnt hydrocarbons. Nitric oxide and nitrogen dioxide were assessed by chemiluminescence analysis. The nitrogen compounds used were selected because of the presence of similar high molecular structure compounds in petroleum and cracking distillates and also in coal liquefaction products.

  8. Contamination Detection and Mitigation Strategies for Unsymmetric Dimethylhydrazine/Nitrogen Tetroxide Non-Combustion Product Residues

    NASA Technical Reports Server (NTRS)

    Greene, Benjamin; Buchanan, Vanessa D.; Baker, David L.

    2006-01-01

    Dimethylamine and nitrite, which are non-combustion reaction products of unsymmetrical dimethylhydrazine (UDMH) and nitrogen tetroxide (NTO) propellants, can contaminate spacesuits during extra-vehicular activity (EVA) operations. They can react with water in the International Space Station (ISS) airlock to form N-nitrosodimethylamine (NDMA), a carcinogen. Detection methods for assessing nitrite and dimethylamine contamination were investigated. The methods are based on color-forming reactions in which intensity of color is proportional to concentration. A concept color detection kit using a commercially available presumptive field test for methamphetamine coupled with nitrite test strips was developed and used to detect dimethylamine and nitrite. Contamination mitigation strategies were also developed.

  9. PCS Nitrogen: Combustion Fan System Optimization Improves Performance and Saves Energy at a Chemical Plant

    SciTech Connect

    Not Available

    2005-01-01

    This U.S. Department of Energy Industrial Technologies Program case study describes how, in 2003, PCS Nitrogen, Inc., improved the efficiency of the combustion fan on a boiler at the company's chemical fertilizer plant in Augusta, Georgia. The project saved $420,000 and 76,400 million British thermal units (MBtu) per year. In addition, maintenance needs declined, because there is now less stress on the fan motor and bearings and less boiler feed water usage. This project was so successful that the company has implemented more efficiency improvements that should result in energy cost savings of nearly $1 million per year.

  10. 40 CFR 86.523-78 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Oxides of nitrogen analyzer... Emission Regulations for 1978 and Later New Motorcycles; Test Procedures § 86.523-78 Oxides of nitrogen... nitrogen are measured, the chemiluminescent oxides of nitrogen analyzer must be checked for NO2 to...

  11. 40 CFR 86.523-78 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 19 2014-07-01 2014-07-01 false Oxides of nitrogen analyzer... Emission Regulations for 1978 and Later New Motorcycles; Test Procedures § 86.523-78 Oxides of nitrogen... nitrogen are measured, the chemiluminescent oxides of nitrogen analyzer must be checked for NO2 to...

  12. 40 CFR 86.523-78 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 19 2012-07-01 2012-07-01 false Oxides of nitrogen analyzer... Emission Regulations for 1978 and Later New Motorcycles; Test Procedures § 86.523-78 Oxides of nitrogen... nitrogen are measured, the chemiluminescent oxides of nitrogen analyzer must be checked for NO2 to...

  13. 40 CFR 86.523-78 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 19 2013-07-01 2013-07-01 false Oxides of nitrogen analyzer... Emission Regulations for 1978 and Later New Motorcycles; Test Procedures § 86.523-78 Oxides of nitrogen... nitrogen are measured, the chemiluminescent oxides of nitrogen analyzer must be checked for NO2 to...

  14. 40 CFR 86.523-78 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 18 2011-07-01 2011-07-01 false Oxides of nitrogen analyzer... Emission Regulations for 1978 and Later New Motorcycles; Test Procedures § 86.523-78 Oxides of nitrogen... nitrogen are measured, the chemiluminescent oxides of nitrogen analyzer must be checked for NO2 to...

  15. Control of nitrogen oxides emissions from stationary sources

    SciTech Connect

    Epperly, W.R.; Broderick, R.G. ); Peter-Hoblyn, J.D. ); Epperly, W.R.; Broderick, R.G. ); Peter-Hoblyn, J.D. )

    1988-01-01

    This paper describes the NOxOUT process for control of nitrogen oxides (NOx) from stationary sources using a wide range of carbonaceous fuels. This process uses urea and/or chemical enhancers to reduce nitrogen oxides at 1,000 to 2,100 {degrees} F. It is ideally suited for retrofit applications and can be used with other control technologies. In commercial tests on conventional boilers and CFBs, up to 85% reduction of NOx has been achieved. Wide use of the process by utilities and industry is expected worldwide as environmental regulations are promulgated.

  16. Process for nitrogen oxides reduction and minimization of the production of other pollutants

    SciTech Connect

    Epperly, W.R.; O'Leary, J.H.; Sullivan, J.C.

    1988-10-25

    This patent describes a process for reducing the concentration of nitrogen oxides in an effluent from the combustion of a carbonaceous fuel while minimizing the production of other pollutants. The process consists of: a. determining the condition of the effluent which exists at a location for introduction of a treatment agent; b. effecting a treatment regimen which comprises introducing a treatment agent into the effluent to treat the effluent to reduce the nitrogen oxides concentration in the effluent under the determined effluent conditions while minimizing the production of other pollutants; c. monitoring the condition of the effluent until a significant alteration in the condition of the effluent is observed; d. adjusting the treatment regimen by varying at least one of the following parameters: (i) dilution and introduction rate of the treatment agent; (ii) components of the treatment agent; and (iii) relative presence of treatment agent components, to effect an adjusted treatment regimen, wherein the adjusted treatment regimen reduces the nitrogen oxides concentration in the effluent under the altered effluent condition while minimizing the production of other pollutants.

  17. Coated oxidizers for combustion stability in solid-propellant rockets

    NASA Technical Reports Server (NTRS)

    Helmy, A. M.; Ramohalli, K. N. R.

    1985-01-01

    Experiments are conducted in a laboratory-scale (6.25-cm diameter) end-burning rocket motor with state-of-the-art, ammonium perchlorate hydroxy-terminated polybutadiene (HTPB), nonmetallized propellants. The concept of tailoring the stability characteristics with a small amount (less than 1 percent by weight) of COATING on the oxidizer is explored. The thermal degradation characteristics of the coat chemical are deduced through theoretical arguments on thermal diffusivity of the composite material (propellant). Several candidate coats are selected and propellants are cast. These propellants (with coated oxidizers) are fired in a laboratory-scale end-burning rocket motor, and real-time pressure histories are recorded. The control propellant (with no coating) is also tested for comparison. The uniformity of the coating, confirmed by SEM pictures and BET adsorption measurements, is thought to be an advance in technology. The frequency of bulk mode instability (BMI), the pressure fluctuation amplitudes, and stability boundaries are correlated with parameters related to the characteristic length (L-asterisk) of the rocket motor. The coated oxidizer propellants, in general, display greater combustion stability than the control (state-of-the-art). The correlations of the various parameters are thought to be new to a field filled with much uncertainty.

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

    PubMed

    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

  19. Process for Nitrogen Oxide Waste Conversion to Fertilizer

    NASA Technical Reports Server (NTRS)

    Lueck, Dale E. (Inventor); Parrish, Clyde F. (Inventor)

    2003-01-01

    The present invention describes a process for converting vapor streams from sources containing at least one nitrogen-containing oxidizing agent therein to a liquid fertilizer composition comprising the steps of: a) directing a vapor stream containing at least one nitrogen-containing oxidizing agent to a first contact zone; b) contacting said vapor stream with water to form nitrogen oxide(s) from said at least one nitrogen-containing oxidizing agent; c) directing said acid(s) as a second stream to a second contact zone; d) exposing said second stream to hydrogen peroxide which is present within said second contact zone in a relative amount of at least 0.1% by weight of said second stream within said second contact zone to convert at least some of any nitrogen oxide species or ions other than in the nitrate form present within said second stream to nitrate ion; e) sampling said stream within said second contact zone to determine the relative amount of hydrogen peroxide within said second contact zone; f) adding hydrogen peroxide to said second contact zone when a level of hydrogen peroxide less than 0.1 % by weight in said second stream is determined by said sampling; g) adding a solution comprising potassium hydroxide to said second stream to maintain a pH between 6.0 and 11.0 within said second stream within said second contact zone to form a solution of potassium nitrate; and h) removing said solution of potassium nitrate from said second contact zone.

  20. Reducing Nitrogen Oxide Emissions: 1996 Compliance with Title IV Limits

    EIA Publications

    1998-01-01

    The purpose of this article is to summarize the existing federal nitrogen oxide (Nox) regulations and the 1996 performance of the 239 Title IV generating units. It also reviews the basics of low-Nox burner technology and presents cost and performance data for retrofits at Title IV units.

  1. Effects of nitrogen fertilizer types on nitrous oxide emissions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The factors controlling nitrous oxide (N2O) emissions after fertilizer nitrogen (N) applications are well studied. This information can be used to choose appropriate fertilizer sources and placement methods in order to minimize direct fertilizer-induced N2O emissions in cropping systems. Several fie...

  2. AIR QUALITY CRITERIA FOR OXIDES OF NITROGEN (Final, 1982)

    EPA Science Inventory

    This document is an evaluation and assessment of scientific information relative to determining the health and welfare effects associated with exposure to various concentrations of nitrogen oxides in ambient air. The document is not intended as a complete, detailed literature rev...

  3. Nitrogen Source Effects on Nitrous Oxide Emissions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Effects of N fertilizer source and tillage on nitrous oxide (N2O) emissions from soils under several irrigated, crop management systems were evaluated. Irrigated corn production systems [conventional-till continuous corn (CT-CC); no-till continuous corn (NT-CC); NT corn-dry bean (NT-CDb); and NT cor...

  4. Demonstration of selective catalytic reduction (SCR) technology for the control of nitrogen oxide (NOx) emissions from high-sulfur coal-fired boilers

    SciTech Connect

    Not Available

    1991-11-01

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from US, Japanese and European catalyst suppliers on a high-sulfur US coal-fired boiler. SCR is a post-combustion nitrogen oxide (NO{sub x}) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NO{sub x} to convert it to nitrogen and water vapor.

  5. Nitrogen doped zinc oxide thin film

    SciTech Connect

    Li, Sonny X.

    2003-12-15

    To summarize, polycrystalline ZnO thin films were grown by reactive sputtering. Nitrogen was introduced into the films by reactive sputtering in an NO{sub 2} plasma or by N{sup +} implantation. All ZnO films grown show n-type conductivity. In unintentionally doped ZnO films, the n-type conductivities are attributed to Zn{sub i}, a native shallow donor. In NO{sub 2}-grown ZnO films, the n-type conductivity is attributed to (N{sub 2}){sub O}, a shallow double donor. In NO{sub 2}-grown ZnO films, 0.3 atomic % nitrogen was found to exist in the form of N{sub 2}O and N{sub 2}. Upon annealing, N{sub 2}O decomposes into N{sub 2} and O{sub 2}. In furnace-annealed samples N{sub 2} redistributes diffusively and forms gaseous N{sub 2} bubbles in the films. Unintentionally doped ZnO films were grown at different oxygen partial pressures. Zni was found to form even at oxygen-rich condition and led to n-type conductivity. N{sup +} implantation into unintentionally doped ZnO film deteriorates the crystallinity and optical properties and leads to higher electron concentration. The free electrons in the implanted films are attributed to the defects introduced by implantation and formation of (N{sub 2}){sub O} and Zni. Although today there is still no reliable means to produce good quality, stable p-type ZnO material, ZnO remains an attractive material with potential for high performance short wavelength optoelectronic devices. One may argue that gallium nitride was in a similar situation a decade ago. Although we did not obtain any p-type conductivity, we hope our research will provide a valuable reference to the literature.

  6. Hydrodynamic Modeling of Oxidizer-Rich Staged Combustion Injector Flow

    NASA Technical Reports Server (NTRS)

    Harper, Brent (Technical Monitor); Canino, J. V.; Heister, S. D.; Garrison, L. A.

    2004-01-01

    The main objective of this work is to determine the unsteady hydrodynamic characteristics of coaxial swirl atomizers of interest in oxidizer-rich staged combustion (ORSC) liquid rocket engines. To this end, the pseudo-density (homogeneous flow) treatment combined with the Marker-and-Cell (MAC) numerical algorithm has been used to develop an axisymmetric with swirl, two-phase, unsteady model. The numerical model is capable of assessing the time-dependent orifice exit conditions and internal mixing for arbitrary fuel and oxidizer gas injection conditions. Parametric studies have been conducted to determine the effect of geometry, gas properties, and liquid properties on the exit massflow rate and velocity. It has been found that the frequency at which the liquid film oscillates increases as the density ratio and thickness increase, decreases as film thickness and liquid swirl velocity increase, and is unaffected by the mixing length. Additionally, it has been determined that the variation in the massflow rate increases as the liquid swirl velocity and liquid film thickness increase, and decreases as the density ratio, collar thickness, and mixing length increase.

  7. Application of staged combustion and reburning to the co-firing of nitrogen-containing wastes

    SciTech Connect

    Linak, W.P.; Mulholland, J.A.; McSorley, J.A.; Hall, R.E.; Srivastava, R.K.

    1991-01-01

    The paper gives results of an evaluation of a 0.6 MW precombustion chamber burner, designed for in-furnace NOx control, high combustion efficiency, and retrofit applications, for use with high nitrogen content fuel/waste mixtures. The 250- to 750-ms residence time precombustion chamber burner mounted on a prototype watertube package boiler simulator used air staging and in-furnace natural gas reburning to control NOx emissions. The paper reports results of research in which the low NOx precombustor was used to examine the co-firing characteristics of a nitrogenated pesticide, containing dinoseb (2-sec-butyl-4,6 dinitrophenol) in a fuel-oil/xylene solvent. The dinoseb formulation as fired contained 6.4% nitrogen. NO emissions without in-furnace NOx control exceeded 4400 ppm (at 0% O2). When NOx controls in the form of air staging and natural gas reburning were used, these emissions were reduced to < 150 ppm (96% reduction). Average CO and total hydrocarbon emissions were typically < 15 and 2 ppm, respectively. No dinoseb was detected in any emission sample, and the destruction efficiency was determined to be > 99.99%. Mutagenicity studies of the dinoseb emissions showed that reburning (used for NOx control) reduced the mutagenic emission factor about 60-70% from that with air staging alone.

  8. 40 CFR 60.4320 - What emission limits must I meet for nitrogen oxides (NOX)?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... nitrogen oxides (NOX)? 60.4320 Section 60.4320 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... nitrogen oxides (NOX)? (a) You must meet the emission limits for NOX specified in Table 1 to this subpart... the emission limits for NOX....

  9. 40 CFR 60.4320 - What emission limits must I meet for nitrogen oxides (NOX)?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... nitrogen oxides (NOX)? 60.4320 Section 60.4320 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... nitrogen oxides (NOX)? (a) You must meet the emission limits for NOX specified in Table 1 to this subpart... the emission limits for NOX....

  10. 40 CFR Appendix S to Part 50 - Interpretation of the Primary National Ambient Air Quality Standards for Oxides of Nitrogen...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Ambient Air Quality Standards for Oxides of Nitrogen (Nitrogen Dioxide) S Appendix S to Part 50 Protection... National Ambient Air Quality Standards for Oxides of Nitrogen (Nitrogen Dioxide) 1. General (a) This... national ambient air quality standards for oxides of nitrogen as measured by nitrogen dioxide (“NO2...

  11. 40 CFR Appendix S to Part 50 - Interpretation of the Primary National Ambient Air Quality Standards for Oxides of Nitrogen...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Ambient Air Quality Standards for Oxides of Nitrogen (Nitrogen Dioxide) S Appendix S to Part 50 Protection... National Ambient Air Quality Standards for Oxides of Nitrogen (Nitrogen Dioxide) 1. General (a) This... national ambient air quality standards for oxides of nitrogen as measured by nitrogen dioxide (“NO2...

  12. 40 CFR Appendix S to Part 50 - Interpretation of the Primary National Ambient Air Quality Standards for Oxides of Nitrogen...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Ambient Air Quality Standards for Oxides of Nitrogen (Nitrogen Dioxide) S Appendix S to Part 50 Protection... National Ambient Air Quality Standards for Oxides of Nitrogen (Nitrogen Dioxide) 1. General (a) This... national ambient air quality standards for oxides of nitrogen as measured by nitrogen dioxide (“NO2...

  13. 40 CFR Appendix S to Part 50 - Interpretation of the Primary National Ambient Air Quality Standards for Oxides of Nitrogen...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Ambient Air Quality Standards for Oxides of Nitrogen (Nitrogen Dioxide) S Appendix S to Part 50 Protection... National Ambient Air Quality Standards for Oxides of Nitrogen (Nitrogen Dioxide) 1. General (a) This... national ambient air quality standards for oxides of nitrogen as measured by nitrogen dioxide (“NO2...

  14. A Sensor System Based on Semi-Conductor Metal Oxide Technology for In Situ Detection of Coal Fired Combustion Gases

    SciTech Connect

    Brent Marquis

    2007-05-31

    Sensor Research and Development Corporation (SRD) proposed a two-phase program to develop a robust, autonomous prototype analyzer for in situ, real-time detection, identification, and measurement of coal-fired combustion gases and perform field-testing at an approved power generation facility. SRD developed and selected sensor materials showing selective responses to carbon monoxide, carbon dioxide, nitric oxide, nitrogen dioxide, ammonia, sulfur dioxide and hydrogen chloride. Sensor support electronics were also developed to enable prototype to function in elevated temperatures without any issues. Field-testing at DOE approved facility showed the ability of the prototype to detect and estimate the concentration of combustion by-products accurately with relatively low false-alarm rates at very fast sampling intervals.

  15. Heat of combustion of tantalum-tungsten oxide thermite composites

    SciTech Connect

    Cervantes, Octavio G.; Kuntz, Joshua D.; Gash, Alexander E.; Munir, Zuhair A.

    2010-12-15

    The heat of combustion of two distinctly synthesized stoichiometric tantalum-tungsten oxide energetic composites was investigated by bomb calorimetry. One composite was synthesized using a sol-gel (SG) derived method in which micrometric-scale tantalum is immobilized in a tungsten oxide three-dimensional nanostructured network structure. The second energetic composite was made from the mixing of micrometric-scale tantalum and commercially available (CA) nanometric tungsten oxide powders. The energetic composites were consolidated using the spark plasma sintering (SPS) technique under a 300 MPa pressure and at temperatures of 25, 400, and 500 C. For samples consolidated at 25 C, the density of the CA composite is 61.65 {+-} 1.07% in comparison to 56.41 {+-} 1.19% for the SG derived composite. In contrast, the resulting densities of the SG composite are higher than the CA composite for samples consolidated at 400 and 500 C. The theoretical maximum density for the SG composite consolidated to 400 and 500 C are 81.30 {+-} 0.58% and 84.42 {+-} 0.62%, respectively. The theoretical maximum density of the CA composite consolidated to 400 and 500 C are 74.54 {+-} 0.80% and 77.90 {+-} 0.79%, respectively. X-ray diffraction analyses showed an increase of pre-reaction of the constituents with an increase in the consolidation temperature. The increase in pre-reaction results in lower stored energy content for samples consolidated to 400 and 500 C in comparison to samples consolidated at 25 C. (author)

  16. 40 CFR 86.123-78 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... New Otto-Cycle Complete Heavy-Duty Vehicles; Test Procedures § 86.123-78 Oxides of nitrogen analyzer calibration. The chemiluminescent oxides of nitrogen analyzer shall receive the following initial and periodic... 40 Protection of Environment 19 2013-07-01 2013-07-01 false Oxides of nitrogen...

  17. 40 CFR 86.123-78 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... New Otto-Cycle Complete Heavy-Duty Vehicles; Test Procedures § 86.123-78 Oxides of nitrogen analyzer calibration. The chemiluminescent oxides of nitrogen analyzer shall receive the following initial and periodic... 40 Protection of Environment 19 2012-07-01 2012-07-01 false Oxides of nitrogen...

  18. 40 CFR 86.123-78 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... New Otto-Cycle Complete Heavy-Duty Vehicles; Test Procedures § 86.123-78 Oxides of nitrogen analyzer calibration. The chemiluminescent oxides of nitrogen analyzer shall receive the following initial and periodic... 40 Protection of Environment 18 2011-07-01 2011-07-01 false Oxides of nitrogen...

  19. 40 CFR 86.123-78 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... New Otto-Cycle Complete Heavy-Duty Vehicles; Test Procedures § 86.123-78 Oxides of nitrogen analyzer calibration. The chemiluminescent oxides of nitrogen analyzer shall receive the following initial and periodic... 40 Protection of Environment 19 2014-07-01 2014-07-01 false Oxides of nitrogen...

  20. 40 CFR 86.123-78 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... New Otto-Cycle Complete Heavy-Duty Vehicles; Test Procedures § 86.123-78 Oxides of nitrogen analyzer calibration. The chemiluminescent oxides of nitrogen analyzer shall receive the following initial and periodic... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Oxides of nitrogen...

  1. 40 CFR 77.6 - Penalties for excess emissions of sulfur dioxide and nitrogen oxides.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... sulfur dioxide and nitrogen oxides. 77.6 Section 77.6 Protection of Environment ENVIRONMENTAL PROTECTION... sulfur dioxide and nitrogen oxides. (a)(1) If excess emissions of sulfur dioxide occur at the affected source or nitrogen oxide occur at an affected unit during any year, the owners and operators...

  2. 40 CFR Table 2 to Subpart Fff of... - Nitrogen Oxides Requirements for Affected Facilities

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 9 2012-07-01 2012-07-01 false Nitrogen Oxides Requirements for... Before September 20, 1994 Pt. 62, Subpt. FFF, Table 2 Table 2 to Subpart FFF of Part 62—Nitrogen Oxides Requirements for Affected Facilities Municipal waste combustor technology Nitrogen oxides emission limit...

  3. 40 CFR Table 2 to Subpart Fff of... - Nitrogen Oxides Requirements for Affected Facilities

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 9 2014-07-01 2014-07-01 false Nitrogen Oxides Requirements for... Before September 20, 1994 Pt. 62, Subpt. FFF, Table 2 Table 2 to Subpart FFF of Part 62—Nitrogen Oxides Requirements for Affected Facilities Municipal waste combustor technology Nitrogen oxides emission limit...

  4. 40 CFR Table 2 to Subpart Fff of... - Nitrogen Oxides Requirements for Affected Facilities

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 8 2011-07-01 2011-07-01 false Nitrogen Oxides Requirements for... Before September 20, 1994 Pt. 62, Subpt. FFF, Table 2 Table 2 to Subpart FFF of Part 62—Nitrogen Oxides Requirements for Affected Facilities Municipal waste combustor technology Nitrogen oxides emission limit...

  5. 40 CFR Table 2 to Subpart Fff of... - Nitrogen Oxides Requirements for Affected Facilities

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 8 2010-07-01 2010-07-01 false Nitrogen Oxides Requirements for... Before September 20, 1994 Pt. 62, Subpt. FFF, Table 2 Table 2 to Subpart FFF of Part 62—Nitrogen Oxides Requirements for Affected Facilities Municipal waste combustor technology Nitrogen oxides emission limit...

  6. 40 CFR 77.6 - Penalties for excess emissions of sulfur dioxide and nitrogen oxides.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... sulfur dioxide and nitrogen oxides. 77.6 Section 77.6 Protection of Environment ENVIRONMENTAL PROTECTION... sulfur dioxide and nitrogen oxides. (a)(1) If excess emissions of sulfur dioxide occur at the affected source or nitrogen oxide occur at an affected unit during any year, the owners and operators...

  7. 40 CFR 92.121 - Oxides of nitrogen analyzer calibration and check.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Oxides of nitrogen analyzer... Procedures § 92.121 Oxides of nitrogen analyzer calibration and check. (a) Quench checks; NO X analyzer. (1... performed in step in paragraph (a)(3)(i) this section. (b) Oxides of nitrogen analyzer calibration....

  8. 40 CFR 86.332-79 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 19 2013-07-01 2013-07-01 false Oxides of nitrogen analyzer... Procedures § 86.332-79 Oxides of nitrogen analyzer calibration. (a) At least monthly during testing, perform.... (2) Zero the oxides of nitrogen analyzer. (3) Connect the outlet of the NOX generator (see Figure...

  9. 40 CFR Table 2 to Subpart Fff of... - Nitrogen Oxides Requirements for Affected Facilities

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 9 2013-07-01 2013-07-01 false Nitrogen Oxides Requirements for... Before September 20, 1994 Pt. 62, Subpt. FFF, Table 2 Table 2 to Subpart FFF of Part 62—Nitrogen Oxides Requirements for Affected Facilities Municipal waste combustor technology Nitrogen oxides emission limit...

  10. 40 CFR 86.332-79 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 19 2012-07-01 2012-07-01 false Oxides of nitrogen analyzer... Procedures § 86.332-79 Oxides of nitrogen analyzer calibration. (a) At least monthly during testing, perform.... (2) Zero the oxides of nitrogen analyzer. (3) Connect the outlet of the NOX generator (see Figure...

  11. 40 CFR 92.121 - Oxides of nitrogen analyzer calibration and check.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Oxides of nitrogen analyzer calibration... Procedures § 92.121 Oxides of nitrogen analyzer calibration and check. (a) Quench checks; NO X analyzer. (1... performed in step in paragraph (a)(3)(i) this section. (b) Oxides of nitrogen analyzer calibration....

  12. 40 CFR 77.6 - Penalties for excess emissions of sulfur dioxide and nitrogen oxides.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... sulfur dioxide and nitrogen oxides. 77.6 Section 77.6 Protection of Environment ENVIRONMENTAL PROTECTION... sulfur dioxide and nitrogen oxides. (a)(1) If excess emissions of sulfur dioxide occur at the affected source or nitrogen oxide occur at an affected unit during any year, the owners and operators...

  13. Foliage plants for indoor removal of the primary combustion gases carbon monoxide and nitrogen dioxide

    NASA Technical Reports Server (NTRS)

    Wolverton, B. C.; Mcdonald, R. C.; Mesick, H. H.

    1985-01-01

    Foliage plants were evaluated for their ability to sorb carbon monoxide and nitrogen dioxide, the two primary gases produced during the combustion of fossil fuels and tobacco. The spider plant (Chlorophytum elatum var. vittatum) could sorb 2.86 micrograms CO/sq cm leaf surface in a 6 h photoperiod. The golden pothos (Scindapsus aureus) sorbed 0.98 micrograms CO/sq cm leaf surface in the same time period. In a system with the spider plant, greater than or equal to 99 percent of an initial concentration of 47 ppm NO2 could be removed in 6 h from a void volume of approximately 0.35 cu m. One spider plant potted in a 3.8 liter container can sorb 3300 micrograms CO and effect the removal of 8500 micrograms NO2/hour, recognizing the fact that a significant fraction of NO2 at high concentrations will be lost by surface sorption, dissolving in moisture, etc.

  14. Fuel nitrogen conversion and release of nitrogen oxides during coal gangue calcination.

    PubMed

    Zhang, Yingyi; Ge, Xinlei; Liu, Lili; Wang, Xidong; Zhang, Zuotai

    2015-05-01

    The pollution emission during the widespread utilization of coal gangue in construction industry has long been neglected. In present study, the NO x release behaviors in a simulation experiment of coal gangue calcination in construction industry were systematically investigated. The corresponding evolution of nitrogen functionalities in coal gangue was also discussed. Results showed that pyrrolic (N-5) and pyridine N-oxide (N-6-O) forms nitrogen were relatively abundant in the raw gangue. During calcination, the N-5 and N-6-O form nitrogen greatly decreased and converted to quaternary nitrogen (N-Q). It was found that NO2 was formed under slowly heating-up condition and at 600 °C under isothermal condition, while only NO was detected with further increase of temperature. From 600 to 1000 °C, the conversion ratio of fuel nitrogen to NO x increased from 8 to 12 %. The char nitrogen was found greatly contribute to NO formation, which may bring difficulty to the abatement of NO x emission during coal gangue calcination. PMID:25501860

  15. APPLICATION OF STAGED COMBUSTION AND REBURNING TO THE CO-FIRING OF NITROGENATED WASTES: CHEMICAL AND BIOLOGICAL ANALYSES

    EPA Science Inventory

    The paper gives results of an evaluation of a 0.6 MW precombustion chamber burner, designed for in-furnace NOx control and high combustion efficiency (CE) for high nitrogen content waste co-firing. The 250- to 750-ms residence time precombustion chamber burner mounted on a protot...

  16. A study on post blast generation of nitrogen oxide

    SciTech Connect

    Lawrence, L.D.

    1996-12-31

    Certain blasting applications are more prone to the generation of significant levels of nitrogen dioxide post blast fumes, more commonly referred to as after blast smoke, generally ranging in color from dark yellow to bright red. This paper reviews basic background chemistry defining the observed fumes and attempts to correlate geology, blast design, and explosive composition effects on the level of nitrogen dioxide that can be observed in various blasting conditions. Additionally, a test setting for evaluating the generation of post blast fumes is presented with pertinent test data detailing generic explosive formulation modifications which effect the overall level of post detonation generation of nitrogen dioxide. Scaled up field trials were completed to evaluate the results obtained using data generated from the test model. Specifically, deep, wet blasting applications in softer geologies with reduced confinement appear to promote the generation of nitric oxide from the explosive composition within the borehole due to partial reaction of the nitrates contained in commercial explosives. As the nitric oxide is released from the muck pile following the detonation of the blast pattern, the gas is readily oxidized to form the colorful after blast fumes of nitrogen dioxide. Using the experimental testing procedure it has been determined that variations to the explosive composition which affect detonation velocity and explosion temperature seem to have a significant effect on the level of nitric oxide formed during a less than ideal detonation. Additional chemical additives to reduce the level of nitric oxide which results from a less than ideal detonation front have been evaluated using the proposed test procedure.

  17. ON-LINE MEASUREMENT OF NITROUS OXIDE FROM COMBUSTION SOURCES BY AUTOMATED GAS CHROMATOGRAPHY

    EPA Science Inventory

    The paper discusses on-line measurement of nitrous oxide (N2O) from combustion sources by automated gas chromatography. ossil fuel combustion is suspected of contributing to measured increases in the ambient concentrations of N2O. haracterization of N2O emissions from fossil fuel...

  18. Effects of pretreatment of coal by CO{sub 2} on nitric oxide emission and unburned carbon in various combustion environments

    SciTech Connect

    Gathitu, B.B.; Chen, W.Y.

    2009-12-15

    Polar solvents are known to swell coal, break hydrogen bonds in the macromolecular structure, and enhance coal liquefaction efficiencies. The effects of the pretreatment of coal using supercritical CO{sub 2} on its physical structure and combustion properties have been studied at the bench-scale level. Emphasis has been placed on NO reburning, NO emissions during air-fired and oxy-fired combustion, and loss on ignition (LOI). Pretreatment was found to increase porosity and to significantly alter the fuel nitrogen reaction pathways. Consequently, NO reduction during reburning using bituminous coal increased, and NO emissions during oxidation of lignite decreased. These two benefits were achieved without negative impacts on LOI.

  19. Oxides of nitrogen and the clouds of Venus

    NASA Technical Reports Server (NTRS)

    Watson, A. J.; Donahue, T. M.; Stedman, D. H.; Knollenberg, R. G.; Ragent, B.; Blamont, J.

    1979-01-01

    Nitric oxide may be produced in the atmosphere of Venus by lightning storms in the clouds. The paper suggests that the odd nitrogen thus formed may play an important part in the chemistry of the clouds. Specifically, production rates for NO2 in the limiting case of high NO concentrations are estimated. If the NO density is high, it is suggested that NO2 may catalyse the production of sulfuric acid aerosol from sulfur dioxide and water vapor, and may also form nitrogen-sulfur compounds such as nitrosyl sulfuric acid, NOHSO4. The large partricles seen by the Pioneer Venus sounder probe may contain considerable quantities of NOHSO4. If this is the case, odd nitrogen must be present in the atmosphere in at least a parts-per-million mixing ratio.

  20. Low Temperature Nitridation of Si Oxide Utilizing Activated Nitrogen

    NASA Astrophysics Data System (ADS)

    Uraoka, Yukiharu; Yano, Hiroshi; Hatayama, Tomoaki; Fuyuki, Takashi

    2002-06-01

    Oxynitride or nitride films are promising materials as a substitute for silicon dioxide because of their high dielectric constant and blocking effect on B penetration. The purpose of this work is to fabricate ultrathin oxynitride films by nitridation of thermal oxide utilizing activated nitrogen at very low temperature. We analyzed nitrogen concentration in the films using X-ray photoelectron spectroscopy. It was confirmed that 9.6 at.%nitrogen was introduced, and that NSi2O was dominant in nitrided films at temperatures as low as 400°C. We succeeded in decreasing the leakage current by one order of magnitude by nitridation of films with thicknesses of 40-60 nm.

  1. Electricity from Coal Combustion: Improving the hydrophobicity of oxidized coals

    NASA Astrophysics Data System (ADS)

    Seehra, Mohindar; Singh, Vivek

    2011-03-01

    To reduce pollution and improve efficiency, undesirable mineral impurities in coals are usually removed in coal preparation plants prior to combustion first by crushing and grinding coals followed by gravity separation using surfactant aided water flotation. However certain coals in the US are not amendable to this process because of their poor flotation characteristics resulting in a major loss of an energy resource. This problem has been linked to surface oxidation of mined coals which make these coals hydrophilic. In this project, we are investigating the surface and water flotation properties of the eight Argonne Premium (AP) coals using x-ray diffraction, IR spectroscopy and zeta potential measurements. The role of the surface functional groups, (phenolic -OH and carboxylic -COOH), produced as a result of chemisorptions of O2 on coals in determining their flotation behavior is being explored. The isoelectric point (IEP) in zeta potential measurements of good vs. poor floaters is being examined in order to improved the hydrophobicity of poor floating coals (e.g. Illinois #6). Results from XRD and IR will be presented along with recent findings from zeta potential measurements, and use of additives to improve hydrophobicity. Supported by USDOE/CAST, Contract #DE-FC26-05NT42457.

  2. Mercury Adsorption and Oxidation over Cobalt Oxide Loaded Magnetospheres Catalyst from Fly Ash in Oxyfuel Combustion Flue Gas.

    PubMed

    Yang, Jianping; Zhao, Yongchun; Chang, Lin; Zhang, Junying; Zheng, Chuguang

    2015-07-01

    Cobalt oxide loaded magnetospheres catalyst from fly ash (Co-MF catalyst) showed good mercury removal capacity and recyclability under air combustion flue gas in our previous study. In this work, the Hg(0) removal behaviors as well as the involved reactions mechanism were investigated in oxyfuel combustion conditions. Further, the recyclability of Co-MF catalyst in oxyfuel combustion atmosphere was also evaluated. The results showed that the Hg(0) removal efficiency in oxyfuel combustion conditions was relative high compared to that in air combustion conditions. The presence of enriched CO2 (70%) in oxyfuel combustion atmosphere assisted the mercury oxidation due to the oxidation of function group of C-O formed from CO2. Under both atmospheres, the mercury removal efficiency decreased with the addition of SO2, NO, and H2O. However, the enriched CO2 in oxyfuel combustion atmosphere could somewhat weaken the inhibition of SO2, NO, and H2O. The multiple capture-regeneration cycles demonstrated that the Co-MF catalyst also present good regeneration performance in oxyfuel combustion atmosphere. PMID:26024429

  3. Formation and control of fuel-nitrogen pollutants in catalytic combustion of coal-derived gases. Final report

    SciTech Connect

    Walsh, P. M.; Bruno, C.; Santavicca, D. A.; Bracco, F. V.

    1980-02-01

    The objective of this program has been the elucidation of the mechanism of high temperature catalytic oxidation of coal-derived gases, including their individual constituents,and the effects of sulfur and nitrogen impurities. Detailed experimental data were obtained and a two-dimensional model is being developed and tested by comparison with the experimental data. When complete, the model can be used to optimize designs of catalytic combustors. The model at present includes axial and radial diffusion and gas and surface chemical reactions. Measured substrate temperatures are input in lieu of complete coupling of gas and solid energy conservation equations and radiative heat transfer. Axial and radial gas temperature and composition profiles inside a catalyst channel were computed and compared with experimental measurements at the catalyst outlet. Experimental investigations were made of carbon monoxide and medium-Btu gas combustion in the presence of platinum supported on a monolithic Cordierite substrate. Axial profiles of substrate temperature, gas temperature, and gas composition were determined at different gas velocities and equivalence ratios. The effects of H/sub 2/S and NH/sub 3/ in the medium-Btu gas were also investigated. Systems were proposed for making resonance absorption and Raman scattering measurements of gas temperature and/or species concentrations in a catalytic reactor. A new pulsed multipass Raman scattering technique for increasing photon yield from a scattering volume was developed.

  4. Nitrogen-doped reduced graphene oxide electrodes for electrochemical supercapacitors.

    PubMed

    Nolan, Hugo; Mendoza-Sanchez, Beatriz; Ashok Kumar, Nanjundan; McEvoy, Niall; O'Brien, Sean; Nicolosi, Valeria; Duesberg, Georg S

    2014-02-14

    Herein we use Nitrogen-doped reduced Graphene Oxide (N-rGO) as the active material in supercapacitor electrodes. Building on a previous work detailing the synthesis of this material, electrodes were fabricated via spray-deposition of aqueous dispersions and the electrochemical charge storage mechanism was investigated. Results indicate that the functionalised graphene displays improved performance compared to non-functionalised graphene. The simplicity of fabrication suggests ease of up-scaling of such electrodes for commercial applications. PMID:24418938

  5. Optical Studies of Nitrogen Oxides in the Stratosphere

    NASA Technical Reports Server (NTRS)

    Noxon, J. F.

    1984-01-01

    Several observational approaches were used to study the oxides of nitrogen in the stratosphere. Two species are accessible in the visible range: NO2 (400 to 450 nm) and NO3 (620 to 670 nm). In the infrared NO, NO2 and HNO3 can be studied easily only if measurements are made from above the tropopause where the water density becomes low. Measurements were carried out both by ground-based techniques as well as aircraft and balloons.

  6. The adsorption enthalpy of nitrogen oxides on crystalline ice

    NASA Astrophysics Data System (ADS)

    Bartels-Rausch, T.; Eichler, B.; Zimmermann, P.; Gäggeler, H. W.; Ammann, M.

    2002-09-01

    The partitioning of nitrogen oxides between ice and air is of importance to the ozone budget in the upper troposphere. In the present study, adsorption of nitrogen oxides on ice was investigated at atmospheric pressure using a chromatographic technique with radioactively labelled nitrogen oxides at low concentrations. The measured retentions solely depended on molecular adsorption and were not influenced by dimerisation, formation of encapsulated hydrates on the ice surface, dissociation of the acids, nor by migration into a quasi-liquid layer or grain boundaries. Based on the chromatographic retention and the model of thermo-chromatography, the standard adsorption enthalpy of -20 kJ mol-1 for NO, -22kJ mol-1 for NO2, -30kJ mol-1 for peroxyacetyl nitrate, -32kJ mol-1 for HON} and -44 kJ mol-1 for HNO3 was calculated. To perform those calculations within the model of thermo-chromatography, the standard adsorption entropy was calculated based on statistical thermodynamics. In this work, two different choices of standard states were applied, and consequently different values of the standard adsorption entropy, of either between -39 kJ mol-1 and -45kJ mol-1, or -164 kJ mol-1 and -169 kJ mol-1 for each nitrogen oxide were derived. The standard adsorption enthalpy was identical for both standard adsorption entropies and thus shown to be independent of the choice of standard state. A brief outlook on environmental implications of our findings indicates that adsorption on ice might be an important removal process of HNO3. In addition, it might be of some importance for HONO and peroxyacetyl nitrate and irrelevant for NO and NO2.

  7. Photochemical doping of graphene oxide with nitrogen for photoluminescence enhancement

    NASA Astrophysics Data System (ADS)

    Liu, Fuchi; Tang, Nujiang; Tang, Tao; Liu, Yuan; Feng, Qian; Zhong, Wei; Du, Youwei

    2013-09-01

    Nitrogen-doped graphene oxide (NGO) was synthesized by irradiation of graphene oxide (GO) in NH3 atmosphere. NGO obtained by irradiation of GO for 10 min has high N content of 13.62 at. %. The photoluminescence (PL) properties of NGO were investigated. The results showed that compared with GO, NGO exhibits significant PL enhancement with a high enhancement ratio of approximately 1501.57%. It may attribute to the high content of amino-like N, which can effectively enhance PL of GO because of the amino conjugation effect.

  8. Photochemical doping of graphene oxide with nitrogen for photoluminescence enhancement

    SciTech Connect

    Liu, Fuchi; Tang, Nujiang; Tang, Tao; Liu, Yuan; Feng, Qian; Zhong, Wei; Du, Youwei

    2013-09-16

    Nitrogen-doped graphene oxide (NGO) was synthesized by irradiation of graphene oxide (GO) in NH{sub 3} atmosphere. NGO obtained by irradiation of GO for 10 min has high N content of 13.62 at. %. The photoluminescence (PL) properties of NGO were investigated. The results showed that compared with GO, NGO exhibits significant PL enhancement with a high enhancement ratio of approximately 1501.57%. It may attribute to the high content of amino-like N, which can effectively enhance PL of GO because of the amino conjugation effect.

  9. Nitrogen oxide abatement by distributed fuel addition. Final report

    SciTech Connect

    Wendt, J.O.L.; Mereb, J.B.

    1991-09-20

    Reburning is examined as a means of NO{sub x} destruction in a 17 kW down-fired pulverized coal combustor. In reburning, a secondary fuel is introduced downstream of the primary flame to produce a reducing zone, favorable to NO destruction, and air is introduced further downstream to complete the combustion. Emphasis is on natural gas reburning and a bituminous coal primary flame. A parametric examination of reburning employing a statistical experimental design, is conducted, complemented by detailed experiments. Mechanisms governing the inter-conversion of nitrogenous species in the fuel rich reburn zone is explored. The effect of reburning on N{sub 2}O emissions, the effect of primary flame mode (premixed and diffusion) and the effect of distributing the reburning fuel, are also investigated.

  10. 40 CFR 50.11 - National primary and secondary ambient air quality standards for oxides of nitrogen (with...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... air quality standards for oxides of nitrogen (with nitrogen dioxide as the indicator). 50.11 Section... quality standards for oxides of nitrogen (with nitrogen dioxide as the indicator). (a) The level of the national primary annual ambient air quality standard for oxides of nitrogen is 53 parts per billion...

  11. 40 CFR 50.11 - National primary and secondary ambient air quality standards for oxides of nitrogen (with...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... air quality standards for oxides of nitrogen (with nitrogen dioxide as the indicator). 50.11 Section... quality standards for oxides of nitrogen (with nitrogen dioxide as the indicator). (a) The level of the national primary annual ambient air quality standard for oxides of nitrogen is 53 parts per billion...

  12. 40 CFR 50.11 - National primary and secondary ambient air quality standards for oxides of nitrogen (with...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... air quality standards for oxides of nitrogen (with nitrogen dioxide as the indicator). 50.11 Section... quality standards for oxides of nitrogen (with nitrogen dioxide as the indicator). (a) The level of the national primary annual ambient air quality standard for oxides of nitrogen is 53 parts per billion...

  13. 40 CFR 50.11 - National primary and secondary ambient air quality standards for oxides of nitrogen (with...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... air quality standards for oxides of nitrogen (with nitrogen dioxide as the indicator). 50.11 Section... quality standards for oxides of nitrogen (with nitrogen dioxide as the indicator). (a) The level of the national primary annual ambient air quality standard for oxides of nitrogen is 53 parts per billion...

  14. Biofilter for removal of nitrogen oxides from contaminated gases under aerobic conditions

    DOEpatents

    Apel, W.A.

    1998-08-18

    A biofilter is described for reducing concentrations of gaseous nitrogen oxides in a polluted gas comprises a porous organic filter bed medium disposed in a housing, the filter bed medium including a mixed culture of naturally occurring denitrifying bacteria for converting the nitrogen oxides to nitrogen gas, carbon dioxide, and water. A method is described of reducing concentrations of nitrogen oxides in polluted gas comprises conducting the polluted gas through the biofilter so that the denitrifying bacteria can degrade the nitrogen oxides. A preferred filter medium is wood compost, however composts of other organic materials are functional. Regulation of pH, moisture content, exogenous carbon sources, and temperature are described. 6 figs.

  15. Biofilter for removal of nitrogen oxides from contaminated gases under aerobic conditions

    DOEpatents

    Apel, William A.

    1998-01-01

    A biofilter for reducing concentrations of gaseous nitrogen oxides in a polluted gas comprises a porous organic filter bed medium disposed in a housing, the filter bed medium including a mixed culture of naturally occurring denitrifying bacteria for converting the nitrogen oxides to nitrogen gas, carbon dioxide, and water. A method of reducing concentrations of nitrogen oxides in polluted gas comprises conducting the polluted gas through the biofilter so that the denitrifying bacteria can degrade the nitrogen oxides. A preferred filter medium is wood compost, however composts of other organic materials are functional. Regulation of pH, moisture content, exogenous carbon sources, and temperature are described.

  16. 40 CFR Table 1 to Subpart Cb of... - Nitrogen Oxides Guidelines for Designated Facilities

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Nitrogen Oxides Guidelines for... September 20, 1994 Pt. 60, Subpt. Cb, Table 1 Table 1 to Subpart Cb of Part 60—Nitrogen Oxides Guidelines for Designated Facilities Municipal waste combustor technology Before April 28, 2009,nitrogen...

  17. 40 CFR 52.235 - Control strategy for ozone: Oxides of nitrogen.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... nitrogen. 52.235 Section 52.235 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... for ozone: Oxides of nitrogen. EPA is approving an exemption request submitted by the Monterey Bay... the area from implementing the oxides of nitrogen (NOX) requirements for reasonably available...

  18. 40 CFR Table 1 to Subpart Cb of... - Nitrogen Oxides Guidelines for Designated Facilities

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Nitrogen Oxides Guidelines for... September 20, 1994 Pt. 60, Subpt. Cb, Table 1 Table 1 to Subpart Cb of part 60—Nitrogen Oxides Guidelines for Designated Facilities Municipal waste combustor technology Before April 28, 2009,nitrogen...

  19. 40 CFR Table 1 to Subpart Cb of... - Nitrogen Oxides Guidelines for Designated Facilities

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Nitrogen Oxides Guidelines for... September 20, 1994 Pt. 60, Subpt. Cb, Table 1 Table 1 to Subpart Cb of part 60—Nitrogen Oxides Guidelines for Designated Facilities Municipal waste combustor technology Before April 28, 2009,nitrogen...

  20. 40 CFR Table 1 to Subpart Cb of... - Nitrogen Oxides Guidelines for Designated Facilities

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Nitrogen Oxides Guidelines for... September 20, 1994 Pt. 60, Subpt. Cb, Table 1 Table 1 to Subpart Cb of part 60—Nitrogen Oxides Guidelines for Designated Facilities Municipal waste combustor technology Before April 28, 2009,nitrogen...

  1. 40 CFR 52.235 - Control strategy for ozone: Oxides of nitrogen.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... nitrogen. 52.235 Section 52.235 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... for ozone: Oxides of nitrogen. EPA is approving an exemption request submitted by the Monterey Bay... the area from implementing the oxides of nitrogen (NOX) requirements for reasonably available...

  2. 40 CFR 52.235 - Control strategy for ozone: Oxides of nitrogen.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... nitrogen. 52.235 Section 52.235 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... for ozone: Oxides of nitrogen. EPA is approving an exemption request submitted by the Monterey Bay... the area from implementing the oxides of nitrogen (NOX) requirements for reasonably available...

  3. 40 CFR 52.235 - Control strategy for ozone: Oxides of nitrogen.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... nitrogen. 52.235 Section 52.235 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... for ozone: Oxides of nitrogen. EPA is approving an exemption request submitted by the Monterey Bay... the area from implementing the oxides of nitrogen (NOX) requirements for reasonably available...

  4. 40 CFR Table 1 to Subpart Cb of... - Nitrogen Oxides Guidelines for Designated Facilities

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Nitrogen Oxides Guidelines for... September 20, 1994 Pt. 60, Subpt. Cb, Table 1 Table 1 to Subpart Cb of Part 60—Nitrogen Oxides Guidelines for Designated Facilities Municipal waste combustor technology Before April 28, 2009,nitrogen...

  5. Oxidative unzipping of stacked nitrogen-doped carbon nanotube cups.

    PubMed

    Dong, Haifeng; Zhao, Yong; Tang, Yifan; Burkert, Seth C; Star, Alexander

    2015-05-27

    We demonstrate a facile synthesis of different nanostructures by oxidative unzipping of stacked nitrogen-doped carbon nanotube cups (NCNCs). Depending on the initial number of stacked-cup segments, this method can yield graphene nanosheets (GNSs) or hybrid nanostructures comprised of graphene nanoribbons partially unzipped from a central nanotube core. Due to the stacked-cup structure of as-synthesized NCNCs, preventing complete exposure of graphitic planes, the unzipping mechanism is hindered, resulting in incomplete unzipping; however, individual, separated NCNCs are completely unzipped, yielding individual nitrogen-doped GNSs. Graphene-based materials have been employed as electrocatalysts for many important chemical reactions, and it has been proposed that increasing the reactive edges results in more efficient electrocatalysis. In this paper, we apply these graphene conjugates as electrocatalysts for the oxygen reduction reaction (ORR) to determine how the increase in reactive edges affects the electrocatalytic activity. This investigation introduces a new method for the improvement of ORR electrocatalysts by using nitrogen dopants more effectively, allowing for enhanced ORR performance with lower overall nitrogen content. Additionally, the GNSs were functionalized with gold nanoparticles (GNPs), resulting in a GNS/GNP hybrid, which shows efficient surface-enhanced Raman scattering and expands the scope of its application in advanced device fabrication and biosensing. PMID:25946723

  6. STATIONARY SOURCE COMBUSTION: AN R/D UPDATE

    EPA Science Inventory

    The paper discusses EPA/IERL-RTP R&D, underway since 1967, to advance combustion technology and the abatement and control of nitrogen oxides (NOx) and other combustion-generated pollutants from major stationary combustion sources. The primary air pollutants under consideration in...

  7. Reaction between nitric oxide and ozone in solid nitrogen

    NASA Technical Reports Server (NTRS)

    Lucas, D.; Pimentel, G. C.

    1979-01-01

    Nitrogen dioxide, NO2, is produced when nitric oxide, NO, and ozone, O3, are suspended in a nitrogen matrix at 11-20 K. The NO2 is formed with first-order kinetics, a 12 K rate constant of (1.4 + or - 0.2) x 0.00001/sec, and an apparent activation energy of 106 + or - 10 cal/mol. Isotopic labeling, variation of concentrations, and cold shield experiments show that the growth of NO2 is due to reaction between ozone molecules and NO monomers, and that the reaction is neither infrared-induced nor does it seem to be a heavy atom tunneling process. Reaction is attributed to nearest-neighbor NO.O3 pairs probably held in a specific orientational relationship that affects the kinetic behavior. When the temperature is raised, more such reactive pairs are generated, presumably by local diffusion. Possible mechanisms are discussed.

  8. Compliance of Royal Naval ships with nitrogen oxide emissions legislation.

    PubMed

    Blatcher, D J; Eames, I

    2013-09-15

    Nitrogen oxide (NOx) emissions from marine diesel engines pose a hazard to human health and the environment. From 2021, demanding emissions limits are expected to be applied to sea areas that the Royal Navy (RN) accesses. We analyze how these future constraints affect the choice of NOx abatement systems for RN ships, which are subject to more design constraints than civilian ships. A weighted matrix approach is used to facilitate a quantitative assessment. For most warships to be built soon after 2021 Lean Nitrogen Traps (LNT) in conjunction with Exhaust Gas Recirculation (EGR) represents a relatively achievable option with fewer drawbacks than other system types. Urea-selective catalytic reduction is likely to be most appropriate for ships that are built to civilian standards. The future technologies that are at an early stage of development are discussed. PMID:23906471

  9. In situ oxidation of carbon-encapsulated cobalt nanocapsules creates highly active cobalt oxide catalysts for hydrocarbon combustion.

    PubMed

    Wang, Han; Chen, Chunlin; Zhang, Yexin; Peng, Lixia; Ma, Song; Yang, Teng; Guo, Huaihong; Zhang, Zhidong; Su, Dang Sheng; Zhang, Jian

    2015-01-01

    Combustion catalysts have been extensively explored to reduce the emission of hydrocarbons that are capable of triggering photochemical smog and greenhouse effect. Palladium as the most active material is widely applied in exhaust catalytic converter and combustion units, but its high capital cost stimulates the tremendous research on non-noble metal candidates. Here we fabricate highly defective cobalt oxide nanocrystals via a controllable oxidation of carbon-encapsulated cobalt nanoparticles. Strain gradients induced in the nanoconfined carbon shell result in the formation of a large number of active sites featuring a considerable catalytic activity for the combustion of a variety of hydrocarbons (methane, propane and substituted benzenes). For methane combustion, the catalyst displays a unique activity being comparable or even superior to the palladium ones. PMID:26074206

  10. In situ oxidation of carbon-encapsulated cobalt nanocapsules creates highly active cobalt oxide catalysts for hydrocarbon combustion

    NASA Astrophysics Data System (ADS)

    Wang, Han; Chen, Chunlin; Zhang, Yexin; Peng, Lixia; Ma, Song; Yang, Teng; Guo, Huaihong; Zhang, Zhidong; Su, Dang Sheng; Zhang, Jian

    2015-06-01

    Combustion catalysts have been extensively explored to reduce the emission of hydrocarbons that are capable of triggering photochemical smog and greenhouse effect. Palladium as the most active material is widely applied in exhaust catalytic converter and combustion units, but its high capital cost stimulates the tremendous research on non-noble metal candidates. Here we fabricate highly defective cobalt oxide nanocrystals via a controllable oxidation of carbon-encapsulated cobalt nanoparticles. Strain gradients induced in the nanoconfined carbon shell result in the formation of a large number of active sites featuring a considerable catalytic activity for the combustion of a variety of hydrocarbons (methane, propane and substituted benzenes). For methane combustion, the catalyst displays a unique activity being comparable or even superior to the palladium ones.

  11. In situ oxidation of carbon-encapsulated cobalt nanocapsules creates highly active cobalt oxide catalysts for hydrocarbon combustion

    PubMed Central

    Wang, Han; Chen, Chunlin; Zhang, Yexin; Peng, Lixia; Ma, Song; Yang, Teng; Guo, Huaihong; Zhang, Zhidong; Su, Dang Sheng; Zhang, Jian

    2015-01-01

    Combustion catalysts have been extensively explored to reduce the emission of hydrocarbons that are capable of triggering photochemical smog and greenhouse effect. Palladium as the most active material is widely applied in exhaust catalytic converter and combustion units, but its high capital cost stimulates the tremendous research on non-noble metal candidates. Here we fabricate highly defective cobalt oxide nanocrystals via a controllable oxidation of carbon-encapsulated cobalt nanoparticles. Strain gradients induced in the nanoconfined carbon shell result in the formation of a large number of active sites featuring a considerable catalytic activity for the combustion of a variety of hydrocarbons (methane, propane and substituted benzenes). For methane combustion, the catalyst displays a unique activity being comparable or even superior to the palladium ones. PMID:26074206

  12. Apparatus for photocatalytic destruction of internal combustion engine emissions during cold start

    DOEpatents

    Janata, Jiri; McVay, Gary L.; Peden, Charles H.; Exarhos, Gregory J.

    1998-01-01

    A method and apparatus for the destruction of emissions from an internal combustion engine wherein a substrate coated with TiO.sub.2 is exposed to a light source in the exhaust system of an internal combustion engine thereby catalyzing oxidation/reduction reactions between gaseous hydrocarbons, carbon monoxide, nitrogen oxides and oxygen in the exhaust of the internal combustion engine.

  13. Canopy-Atmosphere Exchange of Nitrogen Oxides at Harvard Forest.

    NASA Astrophysics Data System (ADS)

    Munger, J. W.; Horii, C. V.; Wofsy, S. C.; Zahniser, M.

    2002-05-01

    Nitrogen oxide exchanges to a mixed deciduous forest have been measured at the Harvard Forest site since 1990. Net fluxes of total nitrogen oxides, NOy are determined by eddy covariance methods. NO and NO2 profiles are determined at 8 levels from the ground to above the forest canopy. A tuneable diode laser spectrometer was deployed during 2000 to directly measure HNO3 concentrations above the canopy and to determine NO2 concentrations and eddy-covariance fluxes. Nitric oxide eddy-covariance fluxes were measured simultaneously with the NO2 fluxes in the late summer and early autumn of 2000. Peroxyacetylnitrate (PAN) concentrations are measured and its loss is compared with that of ozone. Overall, there is a net deposition of NOy to the forest canopy. Nitric acid deposition accounts for this flux during unpolluted periods. When, pollution levels are high, however, NOy deposition appears to exceed the HNO3 deposition. Gradients in NO/NO2 partitioning through the canopy give rise to apparent upward fluxes of NO2 coupled to downward fluxes of NO. Deposition of NO2 is apparent at night. PAN in the surface layer is depleted at night. Comparison with other species will be used to determine whether the PAN loss is due to direct deposition or chemical reaction.

  14. Atmospheric oxidants. [ozone concentration and combustion product aspects in spacecraft design

    NASA Technical Reports Server (NTRS)

    Daniels, G. E.

    1973-01-01

    The ingredients which cause the air pollution are a mixture of oxides of organic matter (mostly nitrogen oxides and hydrocarbons) and ozone. Ozone, although considered one of the rare atmospheric gases, needs consideration in spacecraft design because of its chemical reaction (oxidation) with organic materials, especially rubber, which becomes hard and brittle under tension in a few minutes time. At the earth surface, a maximum of 60 parts per hundred million of oxidants composed of nitrogen oxides, hydrocarbons, sulphur dioxide, sulphur trioxides, peroxides, and ozone can be expected for 72 hours when smog occurs. A table representing distribution of ozone concentration with atmospheric altitude is included.

  15. Nitrogen spark denoxer

    DOEpatents

    Ng, Henry K.; Novick, Vincent J.; Sekar, Ramanujam R.

    1997-01-01

    A NO.sub.X control system for an internal combustion engine includes an oxygen enrichment device that produces oxygen and nitrogen enriched air. The nitrogen enriched air contains molecular nitrogen that is provided to a spark plug that is mounted in an exhaust outlet of an internal combustion engine. As the nitrogen enriched air is expelled at the spark gap of the spark plug, the nitrogen enriched air is exposed to a pulsating spark that is generated across the spark gap of the spark plug. The spark gap is elongated so that a sufficient amount of atomic nitrogen is produced and is injected into the exhaust of the internal combustion engine. The injection of the atomic nitrogen into the exhaust of the internal combustion engine causes the oxides of nitrogen to be reduced into nitrogen and oxygen such that the emissions from the engine will have acceptable levels of NO.sub.X. The oxygen enrichment device that produces both the oxygen and nitrogen enriched air can include a selectively permeable membrane.

  16. Fuel/oxidizer-rich high-pressure preburners. [staged-combustion rocket engine

    NASA Technical Reports Server (NTRS)

    Schoenman, L.

    1981-01-01

    The analyses, designs, fabrication, and cold-flow acceptance testing of LOX/RP-1 preburner components required for a high-pressure staged-combustion rocket engine are discussed. Separate designs of injectors, combustion chambers, turbine simulators, and hot-gas mixing devices are provided for fuel-rich and oxidizer-rich operation. The fuel-rich design addresses the problem of non-equilibrium LOX/RP-1 combustion. The development and use of a pseudo-kinetic combustion model for predicting operating efficiency, physical properties of the combustion products, and the potential for generating solid carbon is presented. The oxygen-rich design addresses the design criteria for the prevention of metal ignition. This is accomplished by the selection of materials and the generation of well-mixed gases. The combining of unique propellant injector element designs with secondary mixing devices is predicted to be the best approach.

  17. DIESEL OXIDATION CATALYST CONTROL OF HYDROCARBON AEROSOLS FROM REACTIVITY CONTROLLED COMPRESSION IGNITION COMBUSTION

    SciTech Connect

    Prikhodko, Vitaly Y; Parks, II, James E; Barone, Teresa L; Curran, Scott; Cho, Kukwon; Lewis Sr, Samuel Arthur; Storey, John Morse; Wagner, Robert M

    2011-01-01

    Reactivity Controlled Compression Ignition (RCCI) is a novel combustion process that utilizes two fuels with different reactivity to stage and control combustion and enable homogeneous combustion. The technique has been proven experimentally in previous work with diesel and gasoline fuels; low NOx emissions and high efficiencies were observed from RCCI in comparison to conventional combustion. In previous studies on a multi-cylinder engine, particulate matter (PM) emission measurements from RCCI suggested that hydrocarbons were a major component of the PM mass. Further studies were conducted on this multi-cylinder engine platform to characterize the PM emissions in more detail and understand the effect of a diesel oxidation catalyst (DOC) on the hydrocarbon-dominated PM emissions. Results from the study show that the DOC can effectively reduce the hydrocarbon emissions as well as the overall PM from RCCI combustion. The bimodal size distribution of PM from RCCI is altered by the DOC which reduces the smaller mode 10 nm size particles.

  18. Production of ozone and nitrogen oxides by laser filamentation

    SciTech Connect

    Petit, Yannick; Henin, Stefano; Kasparian, Jerome; Wolf, Jean-Pierre

    2010-07-12

    We have experimentally measured that laser filaments in air generate up to 10{sup 14}, 3x10{sup 12}, and 3x10{sup 13} molecules of O{sub 3}, NO, and NO{sub 2}, respectively. The corresponding local concentrations in the filament active volume are 10{sup 16}, 3x10{sup 14}, and 3x10{sup 15} cm{sup -3}, and allows efficient oxidative chemistry of nitrogen, resulting in concentrations of HNO{sub 3} in the parts per million range. The latter forming binary clusters with water, our results provide a plausible pathway for the efficient nucleation recently observed in laser filaments.

  19. The Lightning Nitrogen Oxides Model (LNOM): Status and Recent Applications

    NASA Technical Reports Server (NTRS)

    Koshak, William; Khan, Maudood; Peterson, Harold

    2011-01-01

    Improvements to the NASA Marshall Space Flight Center Lightning Nitrogen Oxides Model (LNOM) are discussed. Recent results from an August 2006 run of the Community Multiscale Air Quality (CMAQ) modeling system that employs LNOM lightning NOx (= NO + NO2) estimates are provided. The LNOM analyzes Lightning Mapping Array (LMA) data to estimate the raw (i.e., unmixed and otherwise environmentally unmodified) vertical profile of lightning NOx. The latest LNOM estimates of (a) lightning channel length distributions, (b) lightning 1-m segment altitude distributions, and (c) the vertical profile of NOx are presented. The impact of including LNOM-estimates of lightning NOx on CMAQ output is discussed.

  20. Methods of Nitrogen Oxide Reduction in Pellet Boilers

    NASA Astrophysics Data System (ADS)

    Zandeckis, Aivars; Blumberga, Dagnija; Rochas, Claudio; Veidenbergs, Ivars; Silins, Kaspars

    2010-01-01

    The main goal of this research was to create and test technical solutions that reduce nitrogen oxide emissions in low-capacity pellet boiler. During the research, wood pellets were incinerated in a pellet boiler produced in Latvia with a rated capacity of 15 kW. During the research two NOx emission reduction methods were tested: secondary air supply in the chamber and recirculation of flue gases. Results indicated a drop of NOx concentration only for flue gas recirculation methods. Maximum reduction of 21% was achieved.

  1. [Comprehensive fuzzy evaluation of nitrogen oxide control technologies for coal-fired power plants].

    PubMed

    Yu, Chao; Wang, Shu-xiao; Hao, Ji-ming

    2010-07-01

    A multi-level assessment index system was established to quantitatively and comprehensively evaluate the performance of typical nitrogen oxide control technologies for coal-fired power plants. Comprehensive fuzzy evaluation was conducted to assess six NO, control technologies, including low NO, burner (LNB), over the fire (OFA), flue gas reburning (Reburning), selective catalyst reduction (SCR), selective non-catalyst reduction (SNCR) and hybrid SCR/SNCR. Case studies indicated that combination of SCR and LNB are the optimal choice for wall-fired boilers combusting anthracite coal which requires NO, removal efficiency to be over 70%, however, for W-flame or tangential boilers combusting bituminous and sub-bituminous coal which requires 30% NO, removal, LNB and reburning are better choices. Therefore, we recommend that in the developed and ecological frangible regions, large units burning anthracite or meager coal should install LNB and SCR and other units should install LNB and SNCR. In the regions with environmental capacity, units burning anthracite or meager coal shall install LNB and SNCR, and other units shall apply LNB to reduce NO, emissions. PMID:20825011

  2. Method for combined removal of mercury and nitrogen oxides from off-gas streams

    DOEpatents

    Mendelsohn, Marshall H.; Livengood, C. David

    2006-10-10

    A method for removing elemental Hg and nitric oxide simultaneously from a gas stream is provided whereby the gas stream is reacted with gaseous chlorinated compound to convert the elemental mercury to soluble mercury compounds and the nitric oxide to nitrogen dioxide. The method works to remove either mercury or nitrogen oxide in the absence or presence of each other.

  3. Method of making metal oxide ceramic powders by using a combustible amino acid compound

    DOEpatents

    Pederson, L.R.; Chick, L.A.; Exarhos, G.J.

    1992-05-19

    This invention is directed to the formation of homogeneous, aqueous precursor mixtures of at least one substantially soluble metal salt and a substantially soluble, combustible co-reactant compound, typically an amino acid. This produces, upon evaporation, a substantially homogeneous intermediate material having a total solids level which would support combustion. The homogeneous intermediate material essentially comprises highly dispersed or solvated metal constituents and the co-reactant compound. The intermediate material is quite flammable. A metal oxide powder results on ignition of the intermediate product which combusts same to produce the product powder.

  4. Method of making metal oxide ceramic powders by using a combustible amino acid compound

    DOEpatents

    Pederson, Larry R.; Chick, Lawrence A.; Exarhos, Gregory J.

    1992-01-01

    This invention is directed to the formation of homogeneous, aqueous precursor mixtures of at least one substantially soluble metal salt and a substantially soluble, combustible co-reactant compound, typically an amino acid. This produces, upon evaporation, a substantially homogeneous intermediate material having a total solids level which would support combustion. The homogeneous intermediate material essentially comprises highly dispersed or solvated metal constituents and the co-reactant compound. The intermediate material is quite flammable. A metal oxide powder results on ignition of the intermediate product which combusts same to produce the product powder.

  5. Formation of reactive nitrogen oxides from urban grime photochemistry

    NASA Astrophysics Data System (ADS)

    Baergen, Alyson M.; Donaldson, D. James

    2016-05-01

    Impervious surfaces are ubiquitous in urban environments and constitute a substrate onto which atmospheric constituents can deposit and undergo photochemical and oxidative processing, giving rise to "urban grime" films. HNO3 and N2O5 are important sinks for NOx in the lower atmosphere and may be deposited onto these films, forming nitrate through surface hydrolysis. Although such deposition has been considered as a net loss of NOx from the atmosphere, there is increasing evidence that surface-associated nitrate undergoes further reaction. Here, we examine the gas phase products of the photochemistry of real, field-collected urban grime using incoherent broadband cavity-enhanced absorption spectroscopy (IBBCEAS). Gas phase nitrogen oxides are emitted upon illumination of grime samples and their production increases with ambient relative humidity (RH) up to 35 % after which the production becomes independent of RH. These results are discussed in the context of water uptake onto and evaporation from grime films.

  6. 75 FR 61486 - Review of the Secondary National Ambient Air Quality Standards for Oxides of Nitrogen and Oxides...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-05

    ... Standards for Oxides of Nitrogen and Oxides of Sulfur: Second External Review Draft (75 FR 57463, September... an atmospheric chemistry perspective as well as from an environmental effects perspective,...

  7. Nitrogen Impurity Gettering in Oxide Dispersion Ductilized Chromium

    SciTech Connect

    Brady, Michael P; Anderson, Ian M; Weaver, Mark; Meyer III, Harry M; Walker, Larry R; Miller, Michael K; Larson, David James; Wright, Ian G; Sikka, Vinod K; Rar, Andrei; Pharr, George Mathews; Keiser, James R; Walls, Claudia Alexandra

    2003-01-01

    Work by Scruggs in the 1960s demonstrated that tensile ductility could be achieved at room temperature in powder metallurgically-produced Cr alloyed with MgO. During consolidation, much of the MgO converted to the MgCr{sub 2}O{sub 4} spinel phase, which was hypothesized to getter nitrogen from the Cr, rendering it ductile. We have duplicated this effect, achieving room temperature tensile elongations of 4% for hot-pressed Cr-6MgO-(0-1)Ti (wt.%) and 10% for hot-pressed and extruded Cr-6MgO-0.75Ti. Direct incorporation of nitrogen into the MgCr{sub 2}O{sub 4} phase was not detected; however, impurities, particularly nitrogen and sulfur, were observed to segregate to and/or precipitate at interfaces between the MgO/MgCr{sub 2}O{sub 4} phases and the Cr matrix. Exploratory studies of other non-spinel forming oxide dispersions (La{sub 2}O{sub 3}, TiO{sub 2} and Y{sub 2}O{sub 3}) showed a similar pattern of impurity segregation/precipitation, suggesting that there is nothing unique about spinel dispersions in Cr with regards to impurities. However, none of these other dispersions resulted in similar levels of tensile elongation.

  8. Kinetics of plasma-assisted combustion: effect of non-equilibrium excitation on the ignition and oxidation of combustible mixtures

    NASA Astrophysics Data System (ADS)

    Popov, N. A.

    2016-08-01

    A review of experimental and theoretical investigations of the effect of atomic particles, and electronically and vibrationally excited molecules on the induction delay time and on the shift in the ignition temperature threshold of combustible mixtures is presented. The addition of oxygen and hydrogen atoms to combustible mixtures may cause a significant reduction in the ignition delay time. However, at relatively low initial temperatures, the non-equilibrium effect of the addition of atomic particles in ground electronic states is not pronounced. At the same time, the effect of excited O(1D) atoms on the oxidation and reforming of combustible mixtures is quite significant due to the high rates of reactions of O(1D) atoms with hydrogen and hydrocarbon molecules. In fuel–air mixtures, collisions with O(1D) atoms determine, under certain conditions, the dissociation of hydrocarbon molecules. Singlet oxygen molecules, O2(a1Δ g ), participate both in chain initiation and chain branching reactions, but the effect of O2(a1Δ g ) on the ignition processes is generally less important compared to oxygen atoms. The reactions of vibrationally excited molecules and the processes of VT-relaxation in combustible mixtures are discussed. The production of vibrationally excited N 2(v) molecules in fuel–air mixtures at relatively low electric field is very important. However, at the moment, the effect of the reactions of N 2(v) molecules on the oxidation and ignition of combustible mixtures is not completely clear, and requires further investigation. Therefore, with present knowledge, to reduce the ignition delay time and decrease the temperature threshold of combustive mixtures, the use of gas discharge systems with relatively high E/N values is recommended. In this case the reactions of electronically excited {{\\text{N}}2}≤ft(\\text{A}{}3Σu+,\\text{B}{}3{{\\Pi}g},\\text{C}{}3{{\\Pi}u},\\text{a}{}\\prime 1Σu-\\right) molecules, and atomic particles in ground and

  9. Comparison of Nitrogen Oxide Metabolism among Diverse Ammonia-Oxidizing Bacteria.

    PubMed

    Kozlowski, Jessica A; Kits, K Dimitri; Stein, Lisa Y

    2016-01-01

    Ammonia-oxidizing bacteria (AOB) have well characterized genes that encode and express nitrite reductases (NIR) and nitric oxide reductases (NOR). However, the connection between presence or absence of these and other genes for nitrogen transformations with the physiological production of nitric oxide (NO) and nitrous oxide (N2O) has not been tested across AOB isolated from various trophic states, with diverse phylogeny, and with closed genomes. It is therefore unclear if genomic content for nitrogen oxide metabolism is predictive of net N2O production. Instantaneous microrespirometry experiments were utilized to measure NO and N2O emitted by AOB during active oxidation of ammonia (NH3) or hydroxylamine (NH2OH) and through a period of anoxia. This data was used in concert with genomic content and phylogeny to assess whether taxonomic factors were predictive of nitrogen oxide metabolism. Results showed that two oligotrophic AOB strains lacking annotated NOR-encoding genes released large quantities of NO and produced N2O abiologically at the onset of anoxia following NH3-oxidation. Furthermore, high concentrations of N2O were measured during active O2-dependent NH2OH oxidation by the two oligotrophic AOB in contrast to non-oligotrophic strains that only produced N2O at the onset of anoxia. Therefore, complete nitrifier denitrification did not occur in the two oligotrophic strains, but did occur in meso- and eutrophic strains, even in Nitrosomonas communis Nm2 that lacks an annotated NIR-encoding gene. Regardless of mechanism, all AOB strains produced measureable N2O under tested conditions. This work further confirms that AOB require NOR activity to enzymatically reduce NO to N2O in the nitrifier denitrification pathway, and also that abiotic reactions play an important role in N2O formation, in oligotrophic AOB lacking NOR activity. PMID:27462312

  10. Comparison of Nitrogen Oxide Metabolism among Diverse Ammonia-Oxidizing Bacteria

    PubMed Central

    Kozlowski, Jessica A.; Kits, K. Dimitri; Stein, Lisa Y.

    2016-01-01

    Ammonia-oxidizing bacteria (AOB) have well characterized genes that encode and express nitrite reductases (NIR) and nitric oxide reductases (NOR). However, the connection between presence or absence of these and other genes for nitrogen transformations with the physiological production of nitric oxide (NO) and nitrous oxide (N2O) has not been tested across AOB isolated from various trophic states, with diverse phylogeny, and with closed genomes. It is therefore unclear if genomic content for nitrogen oxide metabolism is predictive of net N2O production. Instantaneous microrespirometry experiments were utilized to measure NO and N2O emitted by AOB during active oxidation of ammonia (NH3) or hydroxylamine (NH2OH) and through a period of anoxia. This data was used in concert with genomic content and phylogeny to assess whether taxonomic factors were predictive of nitrogen oxide metabolism. Results showed that two oligotrophic AOB strains lacking annotated NOR-encoding genes released large quantities of NO and produced N2O abiologically at the onset of anoxia following NH3-oxidation. Furthermore, high concentrations of N2O were measured during active O2-dependent NH2OH oxidation by the two oligotrophic AOB in contrast to non-oligotrophic strains that only produced N2O at the onset of anoxia. Therefore, complete nitrifier denitrification did not occur in the two oligotrophic strains, but did occur in meso- and eutrophic strains, even in Nitrosomonas communis Nm2 that lacks an annotated NIR-encoding gene. Regardless of mechanism, all AOB strains produced measureable N2O under tested conditions. This work further confirms that AOB require NOR activity to enzymatically reduce NO to N2O in the nitrifier denitrification pathway, and also that abiotic reactions play an important role in N2O formation, in oligotrophic AOB lacking NOR activity. PMID:27462312

  11. Reactive nitrogen oxides and ozone above a taiga woodland

    NASA Technical Reports Server (NTRS)

    Bakwin, Peter S.; Jacob, Daniel J.; Wofsy, Steven C.; Munger, J. William; Daube, Bruce C.; Bradshaw, John D.; Sandholm, Scott T.; Talbot, Robert W.; Singh, Hanwant B.; Gregory, Gerald L.

    1994-01-01

    Measurements of reactive nitrogen oxides (NO(x) and NO(y)) and ozone (O3) were made in the planetary boundary layer (PBL) above a taiga woodland in northern Quebec, Canada, during June-August, 1990, as part of NASA Artic Boundary Layer Expedition (ABLE) 3B. Levels of nitrogen oxides and O3 were strongly modulated by the synoptic scale meteorology that brought air from various source regions to the site. Industrial pollution from the Great Lakes region of the U.S. and Canada appears to be a major source for periodic elevation of NO(x), and NO(y) and O3. We find that NO/NO2 ratios at this site at midday were approximately 50% those expected from a simple photochemical steady state between NO(x) and O3, in contrast to our earlier results from the ABLE 3A tundra site. The difference between the taiga and tundra sites is likely due to much larger emissions of biogenic hydrocarbons (particularly isoprene) from the taiga vegetation. Hydrocarbon photooxidation leads to relatively rapid production of peroxy radicals, which convert NO to NO2, at the taiga site. Ratios of NO(x) to NO(y) were typically 2-3 times higher in the PBL during ABLE 3B than during ABLE 3A. This is probably the result of high PAN levels and suppressed formation of HNO3 from NO2 due to high levels of biogenic hydrocarbons at the ABLE 3B site.

  12. Reactive nitrogen oxides and ozone above a taiga woodland

    NASA Astrophysics Data System (ADS)

    Bakwin, Peter S.; Jacob, Daniel J.; Wofsy, Steven C.; Munger, J. William; Daube, Bruce C.; Bradshaw, John D.; Sandholm, Scott T.; Talbot, Robert W.; Singh, Hanwant B.; Gregory, Gerald L.; Blake, Donald R.

    1994-01-01

    Measurements of reactive nitrogen oxides (NOx and NOy) and ozone (O3) were made in the planetary boundary layer (PBL) above a taiga woodland in northern Quebec, Canada, during June-August, 1990, as part of NASA Artie Boundary Layer Expedition (ABLE) 3B. Levels of nitrogen oxides and O3 were strongly modulated by the synoptic scale meteorology that brought air from various source regions to the site. Industrial pollution from the Great Lakes region of the U.S. and Canada appears to be a major source for periodic elevation of NOx, NOy and O3. We find that NO/NO2 ratios at this site at midday were approximately 50% those expected from a simple photochemical steady state between NOx and O3, in contrast to our earlier results from the ABLE 3A tundra site. The difference between the taiga and tundra sites is likely due to much larger emissions of biogenic hydrocarbons (particularly isoprene) from the taiga vegetation. Hydrocarbon photooxidation leads to relatively rapid production of peroxy radicals, which convert NO to NO2, at the taiga site. Ratios of NOx to NOy were typically 2-3 times higher in the PBL during ABLE 3B than during ABLE 3 A. This is probably the result of high PAN levels and suppressed formation of HNO3 from NO2 due to high levels of biogenic hydrocarbons at the ABLE 3B site.

  13. Effect of Co/Ni ratios in cobalt nickel mixed oxide catalysts on methane combustion

    SciTech Connect

    Lim, Tae Hwan; Cho, Sung June; Yang, Hee Sung; Engelhard, Mark H.; Kim, Do Heui

    2015-07-31

    A series of cobalt nickel mixed oxide catalysts with the varying ratios of Co to Ni, prepared by co-precipitation method, were applied to methane combustion. Among the various ratios, cobalt nickel mixed oxides having the ratios of Co to Ni of (50:50) and (67:33) demonstrate the highest activity for methane combustion. Structural analysis obtained from X-ray diffraction (XRD) and extended X-ray absorption fine structure (EXAFS) evidently demonstrates that CoNi (50:50) and (67:33) samples consist of NiCo2O4and NiO phase and, more importantly, NiCo2O4spinel structure is largely distorted, which is attributed to the insertion of Ni2+ions into octahedral sites in Co3O4spinel structure. Such structural dis-order results in the enhanced portion of surface oxygen species, thus leading to the improved reducibility of the catalysts in the low temperature region as evidenced by temperature programmed reduction by hydrogen (H2TPR) and X-ray photoelectron spectroscopy (XPS) O 1s results. They prove that structural disorder in cobalt nickel mixed oxides enhances the catalytic performance for methane combustion. Thus, it is concluded that a strong relationship between structural property and activity in cobalt nickel mixed oxide for methane combustion exists and, more importantly, distorted NiCo2O4spinel structure is found to be an active site for methane combustion.

  14. Interactions between nitrogen cycling and methane oxidation in the pelagic waters of the Gulf of Mexico.

    NASA Astrophysics Data System (ADS)

    Joye, S. B.; Weber, S.; Battles, J.; Montoya, J. P.

    2014-12-01

    Methane is an important greenhouse gas that plays a critical role in climate variation. Although a variety of marine methane sources and sinks have been identified, key aspects of the fate of methane in the ocean remain poorly constrained. At cold seeps in the Gulf of Mexico and elsewhere, methane is introduced into the overlying water column via fluid escape from the seabed. We quantified the fate of methane in the water column overlying seafloor cold seeps, in a brine basin, and at several control sites. Our goals were to determine the factors that regulated methane consumption and assimilation and to explore how these controlling factors varied among and between sites. In particular, we examined the impact of nitrogen availability on methane oxidation and studied the ability of methane oxidizing bacteria to fix molecular nitrogen. Methane oxidation rates were highest in the methane rich bottom waters of natural hydrocabron seeps. At these sites, inorganic nitrogen addition stimulated methane oxidation in laboratory experiments. In vitro shipboard experiments revealed that rates of methane oxidation and nitrogen fixation were correlated strongly, suggesting that nitrogen fixation may have been mediated by methanotrophic bacteria. The highest rates of methane oxidation and nitrogen fixation were observed in the deepwater above at natural hydrocarbon seeps. Rates of methane oxidation were substantial along the chemocline of a brine basin but in these ammonium-rich brines, addition of inorganic nitrogen had little impact on methane oxidation suggesting that methanotrophy in these waters were not nitrogen limited. Control sites exhibited the lowest methane concentrations and methane oxidation rates but even these waters exhibited substantial potential for methane oxidation when methane and inorganic nitrogen concentrations were increased. Together, these data suggest that the availability of inorganic nitrogen plays a critical role in regulating methane oxidation in

  15. Combustion

    NASA Technical Reports Server (NTRS)

    Bulzan, Dan

    2007-01-01

    An overview of the emissions related research being conducted as part of the Fundamental Aeronautics Subsonics Fixed Wing Project is presented. The overview includes project metrics, milestones, and descriptions of major research areas. The overview also includes information on some of the emissions research being conducted under NASA Research Announcements. Objective: Development of comprehensive detailed and reduced kinetic mechanisms of jet fuels for chemically-reacting flow modeling. Scientific Challenges: 1) Developing experimental facilities capable of handling higher hydrocarbons and providing benchmark combustion data. 2) Determining and understanding ignition and combustion characteristics, such as laminar flame speeds, extinction stretch rates, and autoignition delays, of jet fuels and hydrocarbons relevant to jet surrogates. 3) Developing comprehensive kinetic models for jet fuels.

  16. Conversion of nitrogen oxides on commercial photocatalytic dispersion paints

    NASA Astrophysics Data System (ADS)

    Laufs, S.; Burgeth, G.; Duttlinger, W.; Kurtenbach, R.; Maban, M.; Thomas, C.; Wiesen, P.; Kleffmann, J.

    2010-06-01

    In the present study, photocatalytic reactions of nitrogen oxides (NO x = NO + NO 2) were studied on commercial TiO 2 doped facade paints in a flow tube photoreactor under simulated atmospheric conditions. Fast photocatalytic conversion of NO and NO 2 was observed only for the photocatalytic paints and not for non-catalytic reference paints. Nitrous acid (HONO) was formed in the dark on all paints studied, however, it efficiently decomposes under irradiation only on the photocatalytic samples. Thus, it is concluded that photocatalytic paint surfaces do not represent a daytime source of HONO, in contrast to other recent studies on pure TiO 2 surfaces. As main final product, the formation of adsorbed nitric acid/nitrate anion (HNO 3/NO 3-) was observed with near to unity yield. In addition, traces of H 2O 2 were observed in the gas phase only in the presence of O 2. Formation of the greenhouse gas nitrous oxide (N 2O) could be excluded. The uptake kinetics of NO, NO 2 and HONO was very fast under atmospheric conditions (e.g. γ(NO + TiO 2) > 10 -5). Thus, the uptake on urban surfaces (painted houses, etc.) will be limited by transport. For a hypothetically painted street canyon, an average reduction of nitrogen oxide levels of ca. 5% is estimated. Since the harmful HNO 3/NO 3- is formed on the surface of the photoactive paints, whereas it is formed in the gas phase in the atmosphere, the use of photocatalytic paints may also help to reduce acid deposition, e.g. on plants, or nitric acid related health issues.

  17. Modernizing the boiler installation for unit no. 3 at the Kashirskaya GRES to reduce nitrogen oxide emissions

    SciTech Connect

    A.A. Smyshlyaev; S.A. Evdokimov; L.G. Dubovitskaya; I.A. Kochetkov; E. K. Verbovetskii

    2008-03-15

    The purpose of modernizing the Pp-1050-25-545 KGZh (P-50R) boiler is to reduce the emissions of nitrogen oxides (NOx) to levels consistent with modern requirements. The following engineering steps were taken, with liquid slag removal from the boiler, to attain NOx levels of 700-750 mg/m{sup 3} for operation with coal and 125 mg/m{sup 3} for operation with natural gas - three-stage combustion with natural gas as the reducing fuel (about 15% thermal) burning in the recirculating gases; and - use of low-emission coal-dust burners with dust feed at high concentrations, overflow burners, and tertiary draft nozzles to lower the amount of excess air in the active combustion zone. The NOx level was further reduced to 570 g/m{sup 3} (just for operation with coal) by using a selective noncatalytic nitrogen oxide reduction system with injection of ammonia (NH{sub 3}) vapor into the boiler in a zone with temperatures of 950{sup o}C.

  18. Mercury oxidation promoted by a selective catalytic reduction catalyst under simulated Powder River Basin coal combustion conditions.

    PubMed

    Lee, Chun W; Serre, Shannon D; Zhao, Yongxin; Lee, Sung Jun; Hastings, Thomas W

    2008-04-01

    A bench-scale reactor consisting of a natural gas burner and an electrically heated reactor housing a selective catalytic reduction (SCR) catalyst was constructed for studying elemental mercury (Hg(o)) oxidation under SCR conditions. A low sulfur Powder River Basin (PRB) subbituminous coal combustion fly ash was injected into the entrained-flow reactor along with sulfur dioxide (SO2), nitrogen oxides (NOx), hydrogen chloride (HCl), and trace Hg(o). Concentrations of Hg(o) and total mercury (Hg) upstream and downstream of the SCR catalyst were measured using a Hg monitor. The effects of HCl concentration, SCR operating temperature, catalyst space velocity, and feed rate of PRB fly ash on Hg(o) oxidation were evaluated. It was observed that HCl provides the source of chlorine for Hg(o) oxidation under simulated PRB coal-fired SCR conditions. The decrease in Hg mass balance closure across the catalyst with decreasing HCl concentration suggests that transient Hg capture on the SCR catalyst occurred during the short test exposure periods and that the outlet speciation observed may not be representative of steady-state operation at longer exposure times. Increasing the space velocity and operating temperature of the SCR led to less Hg(o) oxidized. Introduction of PRB coal fly ash resulted in slightly decreased outlet oxidized mercury (Hg2+) as a percentage of total inlet Hg and correspondingly resulted in an incremental increase in Hg capture. The injection of ammonia (NH3) for NOx reduction by SCR was found to have a strong effect to decrease Hg oxidation. The observations suggest that Hg(o) oxidation may occur near the exit region of commercial SCR reactors. Passage of flue gas through SCR systems without NH3 injection, such as during the low-ozone season, may also impact Hg speciation and capture in the flue gas. PMID:18422035

  19. Solution combustion synthesis of metal oxide nanomaterials for energy storage and conversion

    NASA Astrophysics Data System (ADS)

    Li, Fa-Tang; Ran, Jingrun; Jaroniec, Mietek; Qiao, Shi Zhang

    2015-10-01

    The design and synthesis of metal oxide nanomaterials is one of the key steps for achieving highly efficient energy conversion and storage on an industrial scale. Solution combustion synthesis (SCS) is a time- and energy-saving method as compared with other routes, especially for the preparation of complex oxides which can be easily adapted for scale-up applications. This review summarizes the synthesis of various metal oxide nanomaterials and their applications for energy conversion and storage, including lithium-ion batteries, supercapacitors, hydrogen and methane production, fuel cells and solar cells. In particular, some novel concepts such as reverse support combustion, self-combustion of ionic liquids, and creation of oxygen vacancies are presented. SCS has some unique advantages such as its capability for in situ doping of oxides and construction of heterojunctions. The well-developed porosity and large specific surface area caused by gas evolution during the combustion process endow the resulting materials with exceptional properties. The relationship between the structural properties of the metal oxides studied and their performance is discussed. Finally, the conclusions and perspectives are briefly presented.

  20. Solution combustion synthesis of metal oxide nanomaterials for energy storage and conversion.

    PubMed

    Li, Fa-tang; Ran, Jingrun; Jaroniec, Mietek; Qiao, Shi Zhang

    2015-11-14

    The design and synthesis of metal oxide nanomaterials is one of the key steps for achieving highly efficient energy conversion and storage on an industrial scale. Solution combustion synthesis (SCS) is a time- and energy-saving method as compared with other routes, especially for the preparation of complex oxides which can be easily adapted for scale-up applications. This review summarizes the synthesis of various metal oxide nanomaterials and their applications for energy conversion and storage, including lithium-ion batteries, supercapacitors, hydrogen and methane production, fuel cells and solar cells. In particular, some novel concepts such as reverse support combustion, self-combustion of ionic liquids, and creation of oxygen vacancies are presented. SCS has some unique advantages such as its capability for in situ doping of oxides and construction of heterojunctions. The well-developed porosity and large specific surface area caused by gas evolution during the combustion process endow the resulting materials with exceptional properties. The relationship between the structural properties of the metal oxides studied and their performance is discussed. Finally, the conclusions and perspectives are briefly presented. PMID:26457657

  1. Experimental study of combustion characteristics of nanoscale metal and metal oxide additives in biofuel (ethanol)

    PubMed Central

    2011-01-01

    An experimental investigation of the combustion behavior of nano-aluminum (n-Al) and nano-aluminum oxide (n-Al2O3) particles stably suspended in biofuel (ethanol) as a secondary energy carrier was conducted. The heat of combustion (HoC) was studied using a modified static bomb calorimeter system. Combustion element composition and surface morphology were evaluated using a SEM/EDS system. N-Al and n-Al2O3 particles of 50- and 36-nm diameters, respectively, were utilized in this investigation. Combustion experiments were performed with volume fractions of 1, 3, 5, 7, and 10% for n-Al, and 0.5, 1, 3, and 5% for n-Al2O3. The results indicate that the amount of heat released from ethanol combustion increases almost linearly with n-Al concentration. N-Al volume fractions of 1 and 3% did not show enhancement in the average volumetric HoC, but higher volume fractions of 5, 7, and 10% increased the volumetric HoC by 5.82, 8.65, and 15.31%, respectively. N-Al2O3 and heavily passivated n-Al additives did not participate in combustion reactively, and there was no contribution from Al2O3 to the HoC in the tests. A combustion model that utilized Chemical Equilibrium with Applications was conducted as well and was shown to be in good agreement with the experimental results. PMID:21711760

  2. Combustion synthesis of CdS/reduced graphene oxide composites and their photocatalytic properties

    SciTech Connect

    Liu, Jianxiu; Pu, Xipeng; Zhang, Dafeng; Seo, Hyo Jin; Du, Kaiping; Cai, Peiqing

    2014-09-15

    Highlights: • CdS/reduced graphene oxide composites were prepared by a combustion method. • The phase changed from hexagonal to cubic phase by increasing the added amount of GO. • The composites showed excellent visible-light photocatalytic properties. • The plausible mechanism of photodegradation was discussed. - Abstract: CdS/reduced graphene oxide composites were synthesized by a simple one-pot combustion method using cadmium nitrate, thiourea and graphite as raw materials. The structure, morphologies, and photocatalytic properties of the as-prepared samples were studied by means of X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, Fourier transform infrared spectroscopy, photoluminescence and ultraviolet–visible spectrophotometry. The results show that the structure of CdS in as-prepared samples changes from hexagonal to cubic phase by increasing the added amount of graphene oxide. During combustion reaction, graphene oxide was reduced to reduced graphene oxide. As-obtained CdS/reduced graphene oxide composites show high visible-light photoactivities, attributed to the minimized recombination of photoinduced electrons and holes and the high surface area of reduced graphene oxide sheets.

  3. Gas turbine combustion and emission control

    NASA Astrophysics Data System (ADS)

    Schetter, B.

    The fundamentals of combustion are discussed in the context of gaseous and liquid fuels and gas turbine fuels. Methods for reducing the emission of pollutants in gas turbines are considered. These emissions are carbon monoxide, unburnt hydrocarbons, smoke/soot, nitrogen oxides, sulphur oxides, and carbon dioxide. The focus is on nitrogen oxides. The general principles of combustor and burner design are considered: aero/can type combustors, silo combustors, and annular combustors. Premix and diffusion flames are discussed.

  4. Low Temperature Combustion using nitrogen enrichment to mitigate nox from large bore natural gas-filled engines.

    SciTech Connect

    Biruduganti, M. S.; Gupta, S. B.; Sekar, R. R.

    2008-01-01

    Low Temperature Combustion (LTC) is identified as one of the pathways to meet the mandatory ultra low NOx emissions levels set by regulatory agencies. This phenomenon can be realized by utilizing various advanced combustion control strategies. The present work discusses nitrogen enrichment using an Air Separation Membrane (ASM) as a better alternative to the mature Exhaust Gas Re-circulation (EGR) technique currently in use. A 70% NOx reduction was realized with a moderate 2% nitrogen enrichment while maintaining power density and simultaneously improving Fuel Conversion Efficiency (FCE). The maximum acceptable Nitrogen Enriched Air (NEA) in a single cylinder spark ignited natural gas engine was investigated in this paper. Any enrichment beyond this level degraded engine performance both in terms of power density and FCE, and unburned hydrocarbon (UHC) emissions. The effect of ignition timing was also studied with and without N2 enrichment. Finally, lean burn versus stoichiometric operation utilizing NEA was compared. Analysis showed that lean burn operation along with NEA is one of the effective pathways for realizing better FCE and lower NOx emissions.

  5. Megacity Emissions and Lifetimes of Nitrogen Oxides Probed from Space

    NASA Astrophysics Data System (ADS)

    Beirle, Steffen; Boersma, K. Folkert; Platt, Ulrich; Lawrence, Mark G.; Wagner, Thomas

    2011-09-01

    Megacities are immense sources of air pollutants, with large impacts on air quality and climate. However, emission inventories in many of them still are highly uncertain, particularly in developing countries. Satellite observations allow top-down estimates of emissions to be made for nitrogen oxides (NOx = NO + NO2), but require poorly quantified a priori information on the NOx lifetime. We present a method for the simultaneous determination of megacity NOx emissions and lifetimes from satellite measurements by analyzing the downwind patterns of NO2 separately for different wind conditions. Daytime lifetimes are ~4 hours at low and mid-latitudes, but ~8 hours in wintertime for Moscow. The derived NOx emissions are generally in good agreement with existing emission inventories, but are higher by a factor of 3 for the Saudi Arabian capital Riyadh.

  6. The role of nitrogen oxides in human adaptation to hypoxia

    PubMed Central

    Levett, Denny Z.; Fernandez, Bernadette O.; Riley, Heather L.; Martin, Daniel S.; Mitchell, Kay; Leckstrom, Carl A.; Ince, Can; Whipp, Brian J.; Mythen, Monty G.; Montgomery, Hugh E.; Grocott, Mike P.; Feelisch, Martin

    2011-01-01

    Lowland residents adapt to the reduced oxygen availability at high altitude through a process known as acclimatisation, but the molecular changes underpinning these functional alterations are not well understood. Using an integrated biochemical/whole-body physiology approach we here show that plasma biomarkers of NO production (nitrite, nitrate) and activity (cGMP) are elevated on acclimatisation to high altitude while S-nitrosothiols are initially consumed, suggesting multiple nitrogen oxides contribute to improve hypoxia tolerance by enhancing NO availability. Unexpectedly, oxygen cost of exercise and mechanical efficiency remain unchanged with ascent while microvascular blood flow correlates inversely with nitrite. Our results suggest that NO is an integral part of the human physiological response to hypoxia. These findings may be of relevance not only to healthy subjects exposed to high altitude but also to patients in whom oxygen availability is limited through disease affecting the heart, lung or vasculature, and to the field of developmental biology. PMID:22355626

  7. Catalyst and method for reduction of nitrogen oxides

    DOEpatents

    Ott, Kevin C.

    2008-05-27

    A Selective Catalytic Reduction (SCR) catalyst was prepared by slurry coating ZSM-5 zeolite onto a cordierite monolith, then subliming an iron salt onto the zeolite, calcining the monolith, and then dipping the monolith either into an aqueous solution of manganese nitrate and cerium nitrate and then calcining, or by similar treatment with separate solutions of manganese nitrate and cerium nitrate. The supported catalyst containing iron, manganese, and cerium showed 80 percent conversion at 113 degrees Celsius of a feed gas containing nitrogen oxides having 4 parts NO to one part NO.sub.2, about one equivalent ammonia, and excess oxygen; conversion improved to 94 percent at 147 degrees Celsius. N.sub.2O was not detected (detection limit: 0.6 percent N.sub.2O).

  8. Catalyst and method for reduction of nitrogen oxides

    DOEpatents

    Ott, Kevin C.

    2008-08-19

    A Selective Catalytic Reduction (SCR) catalyst was prepared by slurry coating ZSM-5 zeolite onto a cordierite monolith, then subliming an iron salt onto the zeolite, calcining the monolith, and then dipping the monolith either into an aqueous solution of manganese nitrate and cerium nitrate and then calcining, or by similar treatment with separate solutions of manganese nitrate and cerium nitrate. The supported catalyst containing iron, manganese, and cerium showed 80 percent conversion at 113 degrees Celsius of a feed gas containing nitrogen oxides having 4 parts NO to one part NO.sub.2, about one equivalent ammonia, and excess oxygen; conversion improved to 94 percent at 147 degrees Celsius. N.sub.2O was not detected (detection limit: 0.6 percent N.sub.2O).

  9. Nitrogen oxides under pressure: stability, ionization, polymerization, and superconductivity

    PubMed Central

    Li, Dongxu; Oganov, Artem R.; Dong, Xiao; Zhou, Xiang-Feng; Zhu, Qiang; Qian, Guangrui; Dong, Huafeng

    2015-01-01

    Nitrogen oxides are textbook class of molecular compounds, with extensive industrial applications. Nitrogen and oxygen are also among the most abundant elements in the universe. We explore the N-O system at 0 K and up to 500 GPa though ab initio evolutionary simulations. Results show that two phase transformations of stable molecular NO2 occur at 7 and 64 GPa, and followed by decomposition of NO2 at 91 GPa. All of the NO+NO3− structures are found to be metastable at T = 0 K, so experimentally reported ionic NO+NO3− is either metastable or stabilized by temperature. N2O5 becomes stable at 9 GPa, and transforms from P-1 to C2/c structure at 51 GPa. NO becomes thermodynamically stable at 198 GPa. This polymeric phase is superconducting (Tc = 2.0 K) and contains a -N-N- backbone. PMID:26575799

  10. Technology innovations and experience curves for nitrogen oxides control technologies.

    PubMed

    Yeh, Sonia; Rubin, Edward S; Taylor, Margaret R; Hounshell, David A

    2005-12-01

    This paper reviews the regulatory history for nitrogen oxides (NOx) pollutant emissions from stationary sources, primarily in coal-fired power plants. Nitrogen dioxide (NO2) is one of the six criteria pollutants regulated by the 1970 Clean Air Act where National Ambient Air Quality Standards were established to protect public health and welfare. We use patent data to show that in the cases of Japan, Germany, and the United States, innovations in NOx control technologies did not occur until stringent government regulations were in place, thus "forcing" innovation. We also demonstrate that reductions in the capital and operation and maintenance (O&M) costs of new generations of high-efficiency NOx control technologies, selective catalytic reduction (SCR), are consistently associated with the increasing adoption of the control technology: the so-called learning-by-doing phenomena. The results show that as cumulative world coal-fired SCR capacity doubles, capital costs decline to approximately 86% and O&M costs to 58% of their original values. The observed changes in SCR technology reflect the impact of technological advance as well as other factors, such as market competition and economies of scale. PMID:16408687

  11. USING POLYMERIC HYDROGEN GETTERS TO PREVENT COMBUSTIBLE ATMOSPHERES DURING INTERIM SAFE STORAGE OF PLUTONIUM OXIDE

    SciTech Connect

    Woodsmall, T

    2007-05-24

    Nuclear Materials Management (NMM) of WSRC has recently installed the capability to perform both non-destructive and destructive examination of 3013 containers of Pu oxide in accordance with DOE-STD-3013. The containers will be opened and the oxide will be sampled for analysis. The remaining bulk oxide must then be safely stored in a non-3013-compliant configuration. Available processing equipment and controls cannot prevent the oxide from adsorbing moisture during this process. Subsequent radiolysis of moisture during storage may generate combustible quantities of gases while waiting final processing, and satisfying DOE Interim Safe Storage Criteria (ISSC) would require that storage containers be vented at impractical frequencies. With support from an independent National Laboratory, WSRC/NMM has demonstrated that a commercial hydrogen getter material will effectively prevent the accumulation of combustible gas concentrations. A project overview, including storage requirements and strategies, as well as getter technology, current test results, and anticipated future developments will be addressed.

  12. Reactive nitrogen oxides and ozone above a taiga woodland

    SciTech Connect

    Bakwin, P.S.; Jacob, D.J.; Wofsy, S.C.; Munger, J.W.; Daube, B.C.; Bradshaw, J.D.; Sandholm, S.T.; Talbot, R.W.; Singh, H.B.; Gregory, G.L.

    1994-01-20

    Measurements of reactive nitrogen oxides (NO{sub x} and NO{sub y}) and ozone (O{sub 3}) were made in the planetary boundary layer (PBL) above a taiga woodland in northern Quebec, Canada, during June-August, 1990, as part of NASA Arctic Boundary Layer Expedition (ABLE) 3B. Levels of nitrogen oxides and O{sub 3} were strongly modulated by the synoptic scale meteorology that brought air from various regions to the site. Industrial pollution from the Great Lakes region of the US and Canada appears to be a major source for periodic elevation of NO{sub x}, NO{sub y} and O{sub 3}. We find that NO/NO{sub 2} ratios at this site at midday were approximately 50% those expected from a simple photochemical steady state between NO{sub x} and O{sub 3}, in contrast to our earlier results from the ABLE 3A tundra site. The difference between the taiga and tundra sites is likely due to much larger emissions of biogenic hydrocarbons (particularly isoprene) from the taiga vegetation. Hydrocarbon photooxidation leads to relatively rapid production of peroxy radicals, which convert NO to NO{sub 2}, at the taiga site. Ratios of NO{sub x} to NO{sub y} were typically 2-3 times higher in the PBL during ABLE 3B than during ABLE 3A. This is probably the result of high PAN levels and suppressed formation of HNO{sub 3} from NO{sub 2} due to high levels of biogenic hydrocarbons at the ABLE 3B site. 36 refs., 7 figs., 3 tabs.

  13. 40 CFR 92.121 - Oxides of nitrogen analyzer calibration and check.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Oxides of nitrogen analyzer calibration and check. 92.121 Section 92.121 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM LOCOMOTIVES AND LOCOMOTIVE ENGINES Test Procedures § 92.121 Oxides of nitrogen...

  14. 76 FR 46083 - Secondary National Ambient Air Quality Standards for Oxides of Nitrogen and Sulfur

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-01

    ...This proposed rule is being issued as required by a consent decree governing the schedule for completion of this review of the air quality criteria and the secondary national ambient air quality standards (NAAQS) for oxides of nitrogen and oxides of sulfur. Based on its review, EPA proposes to retain the current nitrogen dioxide (NO2) and sulfur dioxide (SO2) secondary......

  15. 40 CFR 92.121 - Oxides of nitrogen analyzer calibration and check.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Oxides of nitrogen analyzer calibration and check. 92.121 Section 92.121 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM LOCOMOTIVES AND LOCOMOTIVE ENGINES Test Procedures § 92.121 Oxides of nitrogen...

  16. 40 CFR 60.44Da - Standards for nitrogen oxides (NOX).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standards for nitrogen oxides (NOX). 60... Steam Generating Units § 60.44Da Standards for nitrogen oxides (NOX). (a) Except as provided in....20 Liquid fuels: Coal-derived fuels 210 0.50 Shale oil 210 0.50 All other fuels 130 0.30 Solid...

  17. 40 CFR 60.44Da - Standards for nitrogen oxides (NOX).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standards for nitrogen oxides (NOX). 60... Steam Generating Units § 60.44Da Standards for nitrogen oxides (NOX). (a) Except as provided in....20 Liquid fuels: Coal-derived fuels 210 0.50 Shale oil 210 0.50 All other fuels 130 0.30 Solid...

  18. 40 CFR 60.44Da - Standards for nitrogen oxides (NOX).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standards for nitrogen oxides (NOX). 60... Steam Generating Units § 60.44Da Standards for nitrogen oxides (NOX). (a) Except as provided in....20 Liquid fuels: Coal-derived fuels 210 0.50 Shale oil 210 0.50 All other fuels 130 0.30 Solid...

  19. 40 CFR 60.44Da - Standard for nitrogen oxides (NOX).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for nitrogen oxides (NOX). 60... for nitrogen oxides (NOX). (a) On and after the date on which the initial performance test is... for heat input ng/J lb/MMBtu Gaseous fuels: Coal-derived fuels 210 0.50 All other fuels 86 0.20...

  20. 40 CFR 60.44Da - Standard for nitrogen oxides (NOX).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standard for nitrogen oxides (NOX). 60... for nitrogen oxides (NOX). (a) On and after the date on which the initial performance test is... for heat input ng/J lb/MMBtu Gaseous fuels: Coal-derived fuels 210 0.50 All other fuels 86 0.20...

  1. 40 CFR 52.2351 - Area-wide nitrogen oxides (NOX) exemption.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 4 2011-07-01 2011-07-01 false Area-wide nitrogen oxides (NOX... nitrogen oxides (NOX) exemption. On May 2, 1997, Ursula Trueman, Director, Division of Air Quality, Utah...)(2)(A) of the Clean Air Act as amended in 1990, a section 182(f)(2) NOX Reasonably Available...

  2. 40 CFR 52.2308 - Area-wide nitrogen oxides (NOX) exemptions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 4 2011-07-01 2011-07-01 false Area-wide nitrogen oxides (NOX...-wide nitrogen oxides (NOX) exemptions. (a) The Texas Natural Resource Conservation Commission (TNRCC... exempted from the NOX control requirements of section 182(f) of the Clean Air Act (CAA) as amended in...

  3. 40 CFR 52.2308 - Area-wide nitrogen oxides (NOX) exemptions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Area-wide nitrogen oxides (NOX...-wide nitrogen oxides (NOX) exemptions. (a) The Texas Natural Resource Conservation Commission (TNRCC... exempted from the NOX control requirements of section 182(f) of the Clean Air Act (CAA) as amended in...

  4. 40 CFR 52.2351 - Area-wide nitrogen oxides (NOX) exemption.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Area-wide nitrogen oxides (NOX... nitrogen oxides (NOX) exemption. On May 2, 1997, Ursula Trueman, Director, Division of Air Quality, Utah...)(2)(A) of the Clean Air Act as amended in 1990, a section 182(f)(2) NOX Reasonably Available...

  5. 40 CFR 77.6 - Penalties for excess emissions of sulfur dioxide and nitrogen oxides.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 16 2011-07-01 2011-07-01 false Penalties for excess emissions of sulfur dioxide and nitrogen oxides. 77.6 Section 77.6 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) EXCESS EMISSIONS § 77.6 Penalties for excess emissions of sulfur dioxide and nitrogen oxides. (a)(1)...

  6. EVALUATION OF TWO APPROACHES FOR IMPROVED NITROGEN OXIDES MONITORING IN URBAN ATMOSPHERES

    EPA Science Inventory

    Currently, instrumentation used to monitor nitrogen oxides in urban monitoring networks measure NO and "NOx", where NOx includes NO and NO2. hese NO2 measurements are subject to a positive bias from other oxidized nitrogen species (NOy) and it is believed that NOy measurements ar...

  7. The Determination of Total Nitrogen Oxides in Stack Gases. Phenoldisulfonic Acid Method.

    ERIC Educational Resources Information Center

    Thorpe, Charles J. D.

    The well known Saltzman method for oxides of nitrogen is intended for the determination of these constituents in the ambient atmosphere in the range of a few parts per billion to about 5ppm. However, when sulfur dioxide is present in the gas to be sampled and/or the concentration range of the oxides of nitrogen is from five to several thousand…

  8. 40 CFR 52.136 - Control strategy for ozone: Oxides of nitrogen.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 3 2014-07-01 2014-07-01 false Control strategy for ozone: Oxides of nitrogen. 52.136 Section 52.136 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... for ozone: Oxides of nitrogen. EPA is approving an exemption request submitted by the State of...

  9. 40 CFR 52.136 - Control strategy for ozone: Oxides of nitrogen.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 3 2012-07-01 2012-07-01 false Control strategy for ozone: Oxides of nitrogen. 52.136 Section 52.136 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... for ozone: Oxides of nitrogen. EPA is approving an exemption request submitted by the State of...

  10. 40 CFR 52.136 - Control strategy for ozone: Oxides of nitrogen.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 3 2011-07-01 2011-07-01 false Control strategy for ozone: Oxides of nitrogen. 52.136 Section 52.136 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... for ozone: Oxides of nitrogen. EPA is approving an exemption request submitted by the State of...

  11. 40 CFR 52.2308 - Area-wide nitrogen oxides (NOX) exemptions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 5 2012-07-01 2012-07-01 false Area-wide nitrogen oxides (NOX) exemptions. 52.2308 Section 52.2308 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR...-wide nitrogen oxides (NOX) exemptions. (a) The Texas Natural Resource Conservation Commission...

  12. 40 CFR 52.2351 - Area-wide nitrogen oxides (NOX) exemption.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 5 2013-07-01 2013-07-01 false Area-wide nitrogen oxides (NOX) exemption. 52.2351 Section 52.2351 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... nitrogen oxides (NOX) exemption. On May 2, 1997, Ursula Trueman, Director, Division of Air Quality,...

  13. 40 CFR 60.4320 - What emission limits must I meet for nitrogen oxides (NOX)?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false What emission limits must I meet for nitrogen oxides (NOX)? 60.4320 Section 60.4320 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... nitrogen oxides (NOX)? (a) You must meet the emission limits for NOX specified in Table 1 to this...

  14. 40 CFR 52.2351 - Area-wide nitrogen oxides (NOX) exemption.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 5 2012-07-01 2012-07-01 false Area-wide nitrogen oxides (NOX) exemption. 52.2351 Section 52.2351 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... nitrogen oxides (NOX) exemption. On May 2, 1997, Ursula Trueman, Director, Division of Air Quality,...

  15. 40 CFR 52.2351 - Area-wide nitrogen oxides (NOX) exemption.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 5 2014-07-01 2014-07-01 false Area-wide nitrogen oxides (NOX) exemption. 52.2351 Section 52.2351 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... nitrogen oxides (NOX) exemption. On May 2, 1997, Ursula Trueman, Director, Division of Air Quality,...

  16. 40 CFR 60.4320 - What emission limits must I meet for nitrogen oxides (NOX)?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false What emission limits must I meet for nitrogen oxides (NOX)? 60.4320 Section 60.4320 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... nitrogen oxides (NOX)? (a) You must meet the emission limits for NOX specified in Table 1 to this...

  17. 40 CFR 60.4320 - What emission limits must I meet for nitrogen oxides (NOX)?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false What emission limits must I meet for nitrogen oxides (NOX)? 60.4320 Section 60.4320 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... nitrogen oxides (NOX)? (a) You must meet the emission limits for NOX specified in Table 1 to this...

  18. 40 CFR 52.136 - Control strategy for ozone: Oxides of nitrogen.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 3 2013-07-01 2013-07-01 false Control strategy for ozone: Oxides of nitrogen. 52.136 Section 52.136 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... for ozone: Oxides of nitrogen. EPA is approving an exemption request submitted by the State of...

  19. CRYOGENIC TRAPPING OF OXIDIZED MERCURY SPECIES FROM COMBUSTION FLUE GAS. (R827649)

    EPA Science Inventory

    To further understand the speciation and partitioning of mercury species in combustion systems, it is necessary to be able to identify and quantitate the various forms of oxidized mercury. Currently accepted methods for speciating mercury (Ontario Hydro Method, EPA Method 29, ...

  20. EPA/IFP EUROPEAN WORKSHOP ON THE EMISSION ON NITROUS OXIDE FROM FOSSIL FUEL COMBUSTION

    EPA Science Inventory

    The report summarizes the proceedings of an EPA/Institut Francais du Petrole (IFP) cosponsored workshop addressing direct nitrous oxide (N2O) emission from fossil fuel combustion. The third in a series, it was held at the IFP in Rueil-Malmaison, France, on June 1-2, 1988. Increas...

  1. Reduction of nitrogen oxides with catalytic acid resistant aluminosilicate molecular sieves and ammonia

    DOEpatents

    Pence, Dallas T.; Thomas, Thomas R.

    1980-01-01

    Noxious nitrogen oxides in a waste gas stream such as the stack gas from a fossil-fuel-fired power generation plant or other industrial plant off-gas stream is catalytically reduced to elemental nitrogen and/or innocuous nitrogen oxides employing ammonia as reductant in the presence of a zeolite catalyst in the hydrogen or sodium form having pore openings of about 3 to 10 A.

  2. Demonstration of selective catalytic reduction (SCR) technology for the control of nitrogen oxide (NOx) emissions from high-sulfur coal-fired boilers. Quarterly report No. 5, July--September 1991

    SciTech Connect

    Not Available

    1991-11-01

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from US, Japanese and European catalyst suppliers on a high-sulfur US coal-fired boiler. SCR is a post-combustion nitrogen oxide (NO{sub x}) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NO{sub x} to convert it to nitrogen and water vapor.

  3. Innovative Clean Coal Technology (ICCT). Demonstration of Selective Catalytic Reduction (SCR) technology for the control of Nitrogen Oxide (NO{sub x}) emissions from high-sulfur coal-fired boilers. Technical progress report, third and fourth quarters 1995

    SciTech Connect

    1996-05-01

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from U.S., Japanese, and European catalyst suppliers on a high-sulfur U.S. coal-fired boiler. SCR is a post-combustion nitrogen oxide (NO{sub x}) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NO{sub x} to convert it to nitrogen and water vapor.

  4. Denitrification of combustion gases. [Patent application

    DOEpatents

    Yang, R.T.

    1980-10-09

    A method for treating waste combustion gas to remove the nitrogen oxygen gases therefrom is disclosed wherein the waste gas is first contacted with calcium oxide which absorbs and chemically reacts with the nitrogen oxide gases therein at a temperature from about 100/sup 0/ to 430/sup 0/C. The thus reacted calcium oxide (now calcium nitrate) is then heated at a temperature range between about 430/sup 0/ and 900/sup 0/C, resulting in regeneration of the calcium oxide and production of the decomposition gas composed of nitrogen and nitrogen oxide gas. The decomposition gases can be recycled to the calcium oxide contacting step to minimize the amount of nitrogen oxide gases in the final product gas.

  5. Nitrogen oxide -- Sensors and systems for engine management

    SciTech Connect

    Hiller, J.M.; Bryan, W.L.; Miller, C.E.

    1997-06-24

    The goal of this Cooperative Research and Development (CRADA) effort is to further develop sensors and sensor systems in order to meet current and anticipated air emissions requirements due to the operation of Defense Program facilities and the emission standards imposed on new vehicles operating in this country. Specific objectives of this work are to be able to measure and control on-line and in real-time, emissions, engine operation, air-to-fuel intake ratios, and throttle/accelerator positions in future models of consumer automobiles. Sensor and application specific integrated circuit developments within Lockheed Martin Energy Systems are applicable to the monitoring and engine controls needed by General Motors. In the case of emissions sensors, base technology in thick/thin film sensors and optical systems will be further developed to address the combination of high temperature and accumulated deposits expected in the exhaust stream. Other technologies will also be explored to measure fuel-to-air ratios and technologies such as fiber optic and acoustic wave devices that are applicable to the combustion sensing on an individual base. Two non-contact rotary position sensors have been developed for use in control-by-wire throttle control applications. The two CRADA developed sensors consist of a non-contact, differential capacitance position transducer and a custom complementary metal oxide semiconductor (C-MOS) application specific integrated circuit (ASIC) suitable for use in both passenger and engine compartments.

  6. The defect chemistry of nitrogen in oxides: A review of experimental and theoretical studies

    SciTech Connect

    Polfus, Jonathan M.; Norby, Truls; Haugsrud, Reidar

    2013-02-15

    Incorporation of nitrogen into oxides has in recent years received increased attention as a variable for tuning their functional properties. A vast number of reports have been devoted to improving the photocatalytic properties of TiO{sub 2}, p-type charge carrier concentration in ZnO and the ionic transport properties of ZrO{sub 2} by nitrogen doping. In comparison, the fundamentals of the nitrogen related defect chemistry for a wider range of oxides have been less focused upon. In the present contribution, we review experimental and computational investigations of the nitrogen related defect chemistry of insulating and semiconducting oxides. The interaction between nitrogen and protons is important and emphasized. Specifically, the stability of nitrogen defects such as N{sub O}{sup /}, NH{sub O}{sup Multiplication-Sign} and (NH{sub 2}){sub O}{sup Bullet} is evaluated under various conditions and their atomistic and electronic structure is presented. A final discussion is devoted to the role of nitrogen with respect to transport properties and photocatalytic activity of oxides. - Graphical abstract: Experimental and theoretical investigations of the nitrogen related defect chemistry of a range of wide band gap oxides is reviewed. The interaction between nitrogen dopants and protons is emphasized and described through the atomistic and electronic structure as well as defect chemical processes involving NH and NH{sub 2} defects. Consequently, the physical properties of oxides containing such species are discussed with respect to e.g., diffusion and photocatalytic properties. Highlights: Black-Right-Pointing-Pointer Experimental and theoretical investigations of the nitrogen and hydrogen related defect chemistry of wide band gap oxides is reviewed. Black-Right-Pointing-Pointer The interaction between nitrogen dopants and protons is important and emphasized. Black-Right-Pointing-Pointer Diffusion and photocatalytic properties of N-doped oxides are discussed.

  7. Catalytic combustion of benzene over CuO-CeO2 mixed oxides.

    PubMed

    Jung, Won Young; Lim, Kwon-Taek; Hong, Seong-Soo

    2014-11-01

    Catalytic combustion of benzene over CuO-CeO2 mixed oxides has been investigated. The CuO-CeO2 mixed oxides were prepared by the combustion method using malic acid as an organic fuel and characterized by XRD, XPS and TPR. For the CuO-CeO2 catalyst with a Cu/(Cu + Ce) molar ratio of more than 0.4, highly dispersed copper oxide species were shown at 2θ = 35.5 degrees and 38.8 degrees. The CuO-CeO2 catalyst prepared using 2.0 M malic acid showed the highest activity, with conversion reaching nearly 100% at 350 degrees C. In addition, the highest activity is shown on Cu0.40 (the index denotes the molar ratio Cu/(Cu + Ce)) sample and then it decreases on Cu0.5 and Cu0.7 samples. PMID:25958554

  8. Modeling the chemical evolution of nitrogen oxides near roadways

    NASA Astrophysics Data System (ADS)

    Wang, Yan Jason; DenBleyker, Allison; McDonald-Buller, Elena; Allen, David; Zhang, K. Max

    2011-01-01

    The chemical evolution of nitrogen dioxide (NO 2) and nitrogen monoxide (NO) in the vicinity of roadways is numerically investigated using a computational fluid dynamics model, CFD-VIT-RIT and a Gaussian-based model, CALINE4. CFD-VIT-RIT couples a standard k- ɛ turbulence model for turbulent mixing and the Finite-Rate model for chemical reactions. CALINE4 employs a discrete parcel method, assuming that chemical reactions are independent of the dilution process. The modeling results are compared to the field measurement data collected near two roadways in Austin, Texas, State Highway 71 (SH-71) and Farm to Market Road 973 (FM-973), under parallel and perpendicular wind conditions during the summer of 2007. In addition to ozone (O 3), other oxidants and reactive species including hydroperoxyl radical (HO 2), organic peroxyl radical (RO 2), formaldehyde (HCHO) and acetaldehyde (CH 3CHO) are considered in the transformation from NO to NO 2. CFD-VIT-RIT is shown to be capable of predicting both NO x and NO 2 profiles downwind. CALINE4 is able to capture the NO x profiles, but underpredicts NO 2 concentrations under high wind velocity. Our study suggests that the initial NO 2/NO x ratios have to be carefully selected based on traffic conditions in order to assess NO 2 concentrations near roadways. The commonly assumed NO 2/NO x ratio by volume of 5% may not be suitable for most roadways, especially those with a high fraction of heavy-duty truck traffic. In addition, high O 3 concentrations and high traffic volumes would lead to the peak NO 2 concentration occurring near roadways with elevated concentrations persistent over a long distance downwind.

  9. The contribution of manure and fertilizer nitrogen to atmospheric nitrous oxide since 1860

    NASA Astrophysics Data System (ADS)

    Davidson, Eric A.

    2009-09-01

    Atmospheric nitrous oxide concentrations have been increasing since the industrial revolution and currently account for 6% of total anthropogenic radiative forcing. Microbial production in soils is the dominant nitrous oxide source; this has increased with increasing use of nitrogen fertilizers. However, fertilizer use alone cannot account for the historical trends of atmospheric concentrations of nitrous oxide. Here, I analyse atmospheric concentrations, industrial sources of nitrous oxide, and fertilizer and manure production since 1860. Before 1960, agricultural expansion, including livestock production, may have caused globally significant mining of soil nitrogen, fuelling a steady increase in atmospheric nitrous oxide. After 1960, the rate of the increase rose, due to accelerating use of synthetic nitrogen fertilizers. Using a regression model, I show that 2.0% of manure nitrogen and 2.5% of fertilizer nitrogen was converted to nitrous oxide between 1860 and 2005; these percentage contributions explain the entire pattern of increasing nitrous oxide concentrations over this period. Consideration of processes that re-concentrate soil nitrogen, such as manure production by livestock, improved `hind-casting' of nitrous oxide emissions. As animal protein consumption in human diets increases globally, management of manure will be an important component of future efforts to reduce anthropogenic nitrous oxide sources.

  10. 40 CFR 60.52b - Standards for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... metals, acid gases, organics, and nitrogen oxides. 60.52b Section 60.52b Protection of Environment... § 60.52b Standards for municipal waste combustor metals, acid gases, organics, and nitrogen oxides. (a... (total mass), corrected to 7 percent oxygen. (d) The limits for nitrogen oxides are specified...

  11. 40 CFR 62.14103 - Emission limits for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... combustor metals, acid gases, organics, and nitrogen oxides. 62.14103 Section 62.14103 Protection of... combustor metals, acid gases, organics, and nitrogen oxides. (a) The emission limits for municipal waste... nitrogen oxides in excess of the emission limits listed in table 2 of this subpart for affected...

  12. 40 CFR 60.52b - Standards for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... metals, acid gases, organics, and nitrogen oxides. 60.52b Section 60.52b Protection of Environment... § 60.52b Standards for municipal waste combustor metals, acid gases, organics, and nitrogen oxides. (a... (total mass), corrected to 7 percent oxygen. (d) The limits for nitrogen oxides are specified...

  13. 40 CFR 60.33b - Emission guidelines for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... combustor metals, acid gases, organics, and nitrogen oxides. 60.33b Section 60.33b Protection of Environment..., acid gases, organics, and nitrogen oxides. (a) The emission limits for municipal waste combustor metals... limits for nitrogen oxides at least as protective as the emission limits listed in table 1 of...

  14. 40 CFR 60.33b - Emission guidelines for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... combustor metals, acid gases, organics, and nitrogen oxides. 60.33b Section 60.33b Protection of Environment..., acid gases, organics, and nitrogen oxides. (a) The emission limits for municipal waste combustor metals... limits for nitrogen oxides at least as protective as the emission limits listed in table 1 of...

  15. 40 CFR 62.14103 - Emission limits for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... combustor metals, acid gases, organics, and nitrogen oxides. 62.14103 Section 62.14103 Protection of... combustor metals, acid gases, organics, and nitrogen oxides. (a) The emission limits for municipal waste... nitrogen oxides in excess of the emission limits listed in table 2 of this subpart for affected...

  16. Substitution of Oxides of Nitrogen for Sodium Nitrite

    SciTech Connect

    Yeager, C.J.

    2001-08-22

    The purpose of this report is to discuss the chemistry of nitrous acid, the Savannah River Plant application of nitrogen, environmental effects, and outline a development program for nitrogen replacement of sodium nitrite.

  17. Cross-system comparisons of soil nitrogen transformations and nitrous oxide flux in tropical forest ecosystems

    NASA Technical Reports Server (NTRS)

    Matson, Pamela A.; Vitousek, Peter M.

    1987-01-01

    Soil nitrogen transformations and nitrous oxide flux across the soil-air interface have been measured in a variety of tropical forest sites and correlated with patterns of nitrogen circulation. Nitrogen mineralizaton and nitrification potentials were found to be high in the relatively fertile Costa Rica sites and the Amazonian oxisol/ultisols, intermediate in Amazonian white sand soils, and low in the Hawaiian montane sites. Nitrous oxide fluxes ranged from 0 to 6.2 ng/sq cm per h, and the mean flux per site was shown to be highly correlated with mean nitrogen mineralization.

  18. Methodology development of a time-resolved in-cylinder fuel oxidation analysis: Homogeneous charge compression ignition combustion study application

    SciTech Connect

    Nowak, L.; Guibert, P.; Cavadias, S.; Dupre, S.; Momique, J.C.

    2008-08-15

    A technique was developed and applied to understand the mechanism of fuel oxidation in an internal combustion engine. This methodology determines the fuel and concentrations of various intermediates during the combustion cycle. A time-resolved measurement of a large number of species is the objective of this work and is achieved by the use of a sampling probe developed in-house. A system featuring an electromagnetically actuated sampling valve with internal N{sub 2} dilution was developed for sampling gases coming from the combustion chamber. Combustion species include O{sub 2}, CO{sub 2}, CO, NO{sub x}, fuel components, and hydrocarbons produced due to incomplete combustion of fuel. Combustion gases were collected and analyzed with the objectives of analysis by an automotive exhaust analyzer, separation by gas chromatography, and detection by flame ionization detection and mass spectrometry. The work presented was processed in a homogeneous charge compression ignition combustion mode context. (author)

  19. Influence of environmental factors on removal of oxides of nitrogen by a photocatalytic coating.

    PubMed

    Cros, Clement J; Terpeluk, Alexandra L; Crain, Neil E; Juenger, Maria C G; Corsi, Richard L

    2015-08-01

    Nitrogen oxides (NOx) emitted from combustion processes have elevated concentrations in large urban areas. They cause a range of adverse health effects, acid rain, and are precursors to formation of other atmospheric pollutants, such as ozone, peroxyacetyl nitrate, and inorganic aerosols. Photocatalytic materials containing a semi-conductor that can be activated by sunlight, such as titanium dioxide, have been studied for their ability to remove NOx. The study presented herein aims to elucidate the environmental parameters that most influence the NOx removal efficiency of photocatalytic coatings in hot and humid climate conditions. Concrete samples coated with a commercially available photocatalytic coating (a stucco) and an uncoated sample have been tested in a reactor simulating reasonable summertime outdoor sunlight, relative humidity and temperature conditions in southeast Texas. Two-level full factorial experiments were completed on each sample for five parameters. It was found that contact time, relative humidity and temperature significantly influenced both NO and NO₂removal. Elevated concentrations of organic pollutants reduced NO removal by the coating. Ultra-violet light intensity did not significantly influence removal of NO or NO₂, however, ultra-violet light intensity was involved in a two-factor interaction that significantly influenced removal of both NO and NO₂. PMID:26211635

  20. Synergetic effects of mixed copper-iron oxides oxygen carriers in chemical looping combustion

    SciTech Connect

    Siriwardane, Ranjani; Tian, Hanjing; Simonyi, Thomas; Poston, James

    2013-06-01

    Chemical looping combustion (CLC) is an emerging technology for clean energy production from fuels. CLC produces sequestration-ready CO{sub 2}-streams without a significant energy penalty. Development of efficient oxygen carriers is essential to successfully operate a CLC system. Copper and iron oxides are promising candidates for CLC. Copper oxide possesses high reactivity but it has issues with particle agglomeration due to its low melting point. Even though iron oxide is an inexpensive oxygen carrier it has a slower reactivity. In this study, mixed metal oxide carriers containing iron and copper oxides were evaluated for coal and methane CLC. The components of CuO and Fe{sub 2}O{sub 3} were optimized to obtain good reactivity while maintaining physical and chemical stability during cyclic reactions for methane-CLC and solid-fuel CLC. Compared with single metal oxygen carriers, the optimized Cu–Fe mixed oxide oxygen carriers demonstrated high reaction rate, better combustion conversion, greater oxygen usage and improved physical stability. Thermodynamic calculations, XRD, TGA, flow reactor studies and TPR experiments suggested that there is a strong interaction between CuO and Fe{sub 2}O{sub 3} contributing to a synergistic effect during CLC reactions. The amount of oxygen release of the mixed oxide carrier in the absence of a fuel was similar to that of the single metal oxides. However, in the presence of fuels, the oxygen consumption and the reaction profiles of the mixed oxide carriers were significantly better than that of the single metal oxides. The nature of the fuel not only influenced the reactivity, but also the final reduction status of the oxygen carriers during chemical looping combustion. Cu oxide of the mixed oxide was fully reduced metallic copper with both coal and methane. Fe oxide of the mixed oxide was fully reduced Fe metal with methane but it was reduced to only FeO with coal. Possible mechanisms of how the presence of CuO enhances the

  1. Towards interpreting nitrate-δ15N records in ice cores in terms of nitrogen oxide sources

    NASA Astrophysics Data System (ADS)

    Hastings, M. G.; Buffen, A. M.

    2011-12-01

    The isotopic composition of nitrate preserved in ice cores offers unique potential for reconstructing past contributions of nitrogen oxides (NOx = NO and NO2) to the atmosphere. Sources of NOx imprint a nitrogen stable isotopic (δ15N) signature, which can be conserved during subsequent oxidation to form nitrate. Major sources of NOx include fossil fuels combustion, biomass burning, microbial processes in soils, and lightning, and thus a quantitative tracer of emissions would help detail connections between the atmosphere, the biosphere, and climate. Unfortunately, the δ15N signatures of most NOx sources are not yet well enough constrained to allow for quantitative partitioning, though new methodology for directly collecting NOx for isotopic analysis is promising (Fibiger and Hastings, A43D-0265, AGU 2010). Still, a growing network of ice core δ15N records may offer insight into source signatures, as different sources are important to different regions of the world. For example, a 300-year ice core record of nitrate-δ15N from Summit, Greenland shows a clear and significant 12% (vs. N2) decrease since the Preindustrial that reflects emissions from fossil fuel combustion and/or soils related to changing agricultural practices in North America and Europe. Over the same time period, Antarctic ice cores show no such trend in δ15N. This would be consistent with previous work suggesting that biomass burning and/or stratospheric intrusion of NOx produced from N2O oxidation are dominant sources for nitrate formation at high southern latitudes. In comparison to the polar records, nitrate in tropical ice cores should represent more significant inputs from lightning, microbial processes in soils, and biomass burning. This may be reflected in new results from a high-elevation site in the Peruvian Andes that shows strong seasonal δ15N cycles of up to 15% (vs. N2). We compare and contrast these records in an effort to evaluate the contribution of NOx sources to nitrate over

  2. The influence of oxygen concentration on the combustion of a fuel/oxidizer mixture

    SciTech Connect

    Biteau, H.; Fuentes, A.; Marlair, G.; Torero, J.L.

    2010-04-15

    The aim of the present study is to investigate the influence of the O{sub 2} concentration on the combustion behaviour of a fuel/oxidizer mixture. The material tested is a ternary mixture of lactose, starch, and potassium nitrate, which has already been used in an attempt to estimate heat release rate using the FM-Global Fire Propagation Apparatus. It provides a well-controlled combustion chamber to study the evolution of the combustion products when varying the O{sub 2} concentration, between air and low oxidizer conditions. Different chemical behaviours have been exhibited. When the O{sub 2} concentration was reduced beyond 18%, large variations were observed in the CO{sub 2} and CO concentrations. This critical O{sub 2} concentration seems to be the limit before which the material only uses its own oxidizer to react. On the other hand, mass loss did not highlight this change in chemical reactions and remained similar whatever the test conditions. This presumes that the oxidation of CO into CO{sub 2} are due to reactions occurring in the gas phase especially for large O{sub 2} concentrations. This actual behaviour can be verified using a simplified flammability limit model adapted for the current work. Finally, a sensitivity analysis has been carried out to underline the influence of CO concentration in the evaluation of heat release rate using typical calorimetric methods. The results of this study provide a critical basis for the investigation of the combustion of a fuel/oxidizer mixture and for the validation of future numerical models. (author)

  3. Effect of nitrogen-containing impurities on the activity of perovskitic catalysts for the catalytic combustion of methane.

    PubMed

    Buchneva, Olga; Gallo, Alessandro; Rossetti, Ilenia

    2012-11-01

    LaMnO(3), either pure or doped with 10 mol % Sr, has been prepared by flame pyrolysis in nanostructured form. Such catalysts have been tested for the catalytic flameless combustion of methane, achieving very high catalytic activity. The resistance toward poisoning by some model N-containing impurities has been checked in order to assess the possibility of operating the flameless catalytic combustion with biogas, possibly contaminated by S- or N-based compounds. This would be a significant improvement from the environmental point of view because the application of catalytic combustion to gas turbines would couple improved energy conversion efficiency and negligible noxious emissions, while the use of biogas would open the way to energy production from a renewable source by means of very efficient technologies. A different behavior has been observed for the two catalysts; namely, the undoped sample was more or less heavily poisoned, whereas the Sr-doped sample showed slightly increasing activity upon dosage of N-containing compounds. A possible reaction mechanism has been suggested, based on the initial oxidation of the organic backbone, with the formation of NO. The latter may adsorb more or less strongly depending on the availability of surface oxygen vacancies (i.e., depending on doping). Decomposition of NO may leave additional activated oxygen species on the surface, available for low-temperature methane oxidation and so improving the catalytic performance. PMID:23039114

  4. Material combustion in oxidant flows: Self-similar solutions

    NASA Astrophysics Data System (ADS)

    Tyurenkova, V. V.; Smirnova, M. N.

    2016-03-01

    The paper presents exact solution for the problem of condensed material surface burning in a flow of oxidant in the case of steady flame over fuel layer. The solution is obtained within the frame of assumption of fuel gasification and gas phase chemical reacting in a diffusion flame. The regression rate of the material surface in the turbulent and laminar flow regimes is studied. The zones corresponding to kinetic and diffusion regime are determined.

  5. Production of Nitrogen Oxides by Laboratory Simulated Transient Luminous Events

    NASA Astrophysics Data System (ADS)

    Peterson, H.; Bailey, M.; Hallett, J.; Beasley, W.

    2007-12-01

    Restoration of the polar stratospheric ozone layer has occurred at rates below those originally expected following reductions in chlorofluorocarbon (CFC) usage. Additional reactions affecting ozone depletion now must also be considered. This research examines nitrogen oxides (NOx) produced in the middle atmosphere by transient luminous events (TLEs), with NOx production in this layer contributing to the loss of stratospheric ozone. In particular, NOx produced by sprites in the mesosphere would be transported to the polar stratosphere via the global meridional circulation and downward diffusion. A pressure-controlled vacuum chamber was used to simulate middle atmosphere pressures, while a power supply and in-chamber electrodes were used to simulate TLEs in the pressure controlled environment. Chemiluminescence NOx analyzers were used to sample NOx produced by the chamber discharges- originally a Monitor Labs Model 8440E, later a Thermo Environment Model 42. Total NOx production for each discharge as well as NOx per ampere of current and NOx per Joule of discharge energy were plotted. Absolute NOx production was greatest for discharge environments with upper tropospheric pressures (100-380 torr), while NOx/J was greatest for discharge environments with stratospheric pressures (around 10 torr). The different production efficiencies in NOx/J as a function of pressure pointed to three different production regimes, each with its own reaction mechanisms: one for tropospheric pressures, one for stratospheric pressures, and one for upper stratospheric to mesospheric pressures (no greater than 1 torr).

  6. Nitrogen oxide removal dynamic process through 15 Ns DBD technique

    NASA Astrophysics Data System (ADS)

    Wang, Xiaojun; Zhang, Lianshui; Lai, Weidong; Liu, Fengliang

    2015-05-01

    Nitrogen oxides exhaust gas assumes the important responsibility on air pollution by forming acid rain. This paper discusses the NO removal mechanism in 15 ns pulse dielectric barrier discharge (DBD) plasma through experimental and simulating method. Emission spectra collected from plasma are evaluated as sourced from N+ and O(3P). The corresponding zero-dimensional model is established and verified through comparing the simulated concentration evolution and the experimental time-resolved spectra of N+. The electron impact ionization plays major role on NO removal and the produced NO+ are further decomposed into N+ and O(3P) through electron impact dissociative excitation rather than the usual reported dissociative recombination process. Simulation also indicates that the removal process can be accelerated by NO inputted at lower initial concentration or electrons streamed at higher concentration, due to the heightened electron impact probability on NO molecules. The repetitive pulse discharge is a benefit for improving the NO removal efficiency by effectively utilizing the radicals generated from the previous pulse under the condition that the pulse period should be shorter enough to ignore the spatial diffusion of radicals. Finally, slight attenuation on NO removal has been experimentally and simulatively observed after N2 mixed, due to the competitive consumption of electrons.

  7. Nitrogen limitation of nitrous oxide fluxes in the tropical Andes

    NASA Astrophysics Data System (ADS)

    Teh, Y.; Diem, T.; Morley, N.; Baggs, E.

    2013-12-01

    Montane Peruvian ecosystems are a regional atmospheric source of nitrous oxide (N2O) releasing at least 0.80 × 0.44 kg N ha-1 a-1. Field and laboratory experiments across a 3000 m elevation gradient in the Kosñipata Valley, Manu National Park, Peru indicate that nitrogen (N) availability, particularly nitrate (NO3-) content, are central to regulating N2O fluxes. Water-filled pore space (WFPS), soil moisture content, and carbon (C) availability play a secondary role in modulating fluxes. Field-based flux measurements indicate that N2O emissions and NO3- availability were inversely proportional with altitude, with lower elevation ecosystems (premontane forest, lower montane forest) emitting significantly more N2O and containing more NO3- than higher elevation ones (upper montane forest, montane grasslands). In lower elevation ecosystems, where NO3- was more abundant, N2O fluxes were influenced by WFPS, soil moisture, and to lesser extent by C mineralization rates. In contrast, in higher elevation ecosystems, WFPS and soil moisture content played little or no role in modulating fluxes, and N2O fluxes appeared to be more strongly driven by N availability.

  8. Transport of nitrogen oxides through the winter mesopause in HAMMONIA

    NASA Astrophysics Data System (ADS)

    Meraner, Katharina; Schmidt, Hauke

    2016-03-01

    We analyze the importance of individual transport processes for the winter polar downward transport of nitrogen oxides (NOx) from the thermosphere to the mesosphere. The downward transport of NOx produced by energetic particle precipitation induces chemical alterations in the middle atmosphere and influences ozone chemistry. However, it remains unclear how much each transport process contributes to the downward transport. We use simulations of the atmospheric general circulation and chemistry model HAMMONIA (Hamburg Model of Neutral and Ionized Atmosphere) for the extended winter 2008/2009 with a passive tracer. The model enables us to separate the contributions of advection, eddy and molecular diffusion on the total transport by switching off processes. The results show that molecular diffusion and resolved vertical mixing due to advection effectively transport NOx to the mesosphere. While the impact of molecular diffusion on the transport rapidly decreases below 0.001 hPa, the impact of advection increases. Around the central date of the sudden stratospheric warming in January 2009, advection is strongly enhanced in the thermosphere and mesosphere and the downward transport through the mesopause region is almost entirely driven by advection. Eddy diffusion has limited impact on the transport in the upper mesosphere and negligible impact on the transport in the thermosphere. If eddy diffusion is enhanced as suggested by observations, it can potentially have a larger impact on transport through the mesopause than was previously assumed.

  9. Reduction of Nitrogen Oxide Emissions for lean Burn Engine Technology

    SciTech Connect

    McGill, R.N.

    1998-08-04

    Lean-burn engines offer the potential for significant fuel economy improvements in cars and trucks, perhaps the next great breakthrough in automotive technology that will enable greater savings in imported petroleum. The development of lean-burn engines, however, has been an elusive goal among automakers because of the emissions challenges associated with lead-burn engine technology. Presently, cars operate with sophisticated emissions control systems that require the engine's air-fuel ratio to be carefully controlled around the stoichiometric point (chemically correct mixture). Catalysts in these systems are called "three-way" catalysts because they can reduce hydrocarbon, carbon monoxide, and nitrogen oxide emissions simultaneously, but only because of the tight control of the air-fuel ratio. The purpose of this cooperative effort is to develop advanced catalyst systems, materials, and necessary engine control algorithms for reducing NOX emissions in oxygen-rich automotive exhaust (as with lean-burn engine technology) to meet current and near-future mandated Clean Air Act standards. These developments will represent a breakthrough in both emission control technology and automobile efficiency. The total project is a joint effort among five national laboratories, together with US CAR. The role of Lockheed-Martin Energy Systems in the total project is two fold: characterization of catalyst performance through laboratory evaluations from bench-scale flow reactor tests to engine laboratory tests of full-scale prototype catalysts, and microstructural characterization of catalyst material before and after test stand and/or engine testing.

  10. Seasonality of reactive nitrogen oxides (NOy) at Neumayer Station, Antarctica

    NASA Astrophysics Data System (ADS)

    Weller, R.; Jones, A. E.; Wille, A.; Jacobi, H.-W.; McIntyre, H. P.; Sturges, W. T.; Huke, M.; Wagenbach, D.

    2002-12-01

    NO, NOy (total reactive nitrogen oxides), gaseous HNO3, and particulate nitrate (p-NO3-) were measured at Neumayer Station from February 1999 to January 2000. In addition, during February 1999, the NOy component species peroxyacetyl nitrate (PAN) and methyl, ethyl, i-propyl, and n-propyl nitrates were determined. We found a mean NOy mixing ratio of 46 ± 29 pptv, with significantly higher values between February and end of May (58 ± 35 pptv). Between February and November, the (HNO3 + p-NO3-)/NOy ratio was extremely low (around 0.22) and in contrast to NOy the seasonality of p-NO3- and HNO3 showed a distinct maximum in November and December, leading to a (HNO3 + p-NO3-)/NOy ratio of 0.66. Trajectory analyses and radioisotope measurements (7Be, 10Be, 210Pb, and 222Rn) indicated that the upper troposphere or stratosphere was the main source region of the observed NOy with a negligible contribution of ground-level sources at northward continents. Frequent maxima of NOy mixing ratios up to 100 pptv are generally associated with air mass transport from the free troposphere of continental Antarctica, while air masses with the lowest NOy mixing ratios were typically advected from the marine boundary layer.

  11. Water Injection on Commercial Aircraft to Reduce Airport Nitrogen Oxides

    NASA Technical Reports Server (NTRS)

    Daggett, David L.; Hendricks, Robert C.; Fucke, Lars; Eames, David J. H.

    2010-01-01

    The potential nitrogen oxide (NO(x) reductions, cost savings, and performance enhancements identified in these initial studies of waterinjection technology strongly suggest that it be further pursued. The potential for engine maintenance cost savings from this system should make it very attractive to airline operators and assure its implementation. Further system tradeoff studies and engine tests are needed to answer the optimal system design question. Namely, would a low-risk combustor injection system with 70- to 90-percent NO(x) reduction be preferable, or would a low-pressure compressor (LPC) misting system with only 50-percent NO(x) reduction but larger turbine inlet temperature reductions be preferable? The low-pressure compressor injection design and operability issues identified in the report need to be addressed because they might prevent implementation of the LPC type of water-misting system. If water-injection technology challenges are overcome, any of the systems studied would offer dramatic engine NO(x) reductions at the airport. Coupling this technology with future emissions-reduction technologies, such as fuel-cell auxiliary power units will allow the aviation sector to address the serious challenges of environmental stewardship, and NO(x) emissions will no longer be an issue at airports.

  12. Modeling of single char combustion, including CO oxidation in its boundary layer

    SciTech Connect

    Lee, C.H.; Longwell, J.P.; Sarofim, A.F.

    1994-10-25

    The combustion of a char particle can be divided into a transient phase where its temperature increases as it is heated by oxidation, and heat transfer from the surrounding gas to an approximately constant temperature stage where gas phase reaction is important and which consumes most of the carbon and an extinction stage caused by carbon burnout. In this work, separate models were developed for the transient heating where gas phase reactions were unimportant and for the steady temperature stage where gas phase reactions were treated in detail. The transient char combustion model incorporates intrinsic char surface production of CO and CO{sub 2}, internal pore diffusion and external mass and heat transfer. The model provides useful information for particle ignition, burning temperature profile, combustion time, and carbon consumption rate. A gas phase reaction model incorporating the full set of 28 elementary C/H/O reactions was developed. This model calculated the gas phase CO oxidation reaction in the boundary layer at particle temperatures of 1250 K and 2500 K by using the carbon consumption rate and the burning temperature at the pseudo-steady state calculated from the temperature profile model but the transient heating was not included. This gas phase model can predict the gas species, and the temperature distributions in the boundary layer, the CO{sub 2}/CO ratio, and the location of CO oxidation. A mechanistic heat and mass transfer model was added to the temperature profile model to predict combustion behavior in a fluidized bed. These models were applied to data from the fluidized combustion of Newlands coal char particles. 52 refs., 60 figs.

  13. Effects of nitrogen fertilization and soil inoculation of sulfur oxidizing or nitrogen fixing bacteria on onion plant growth and yield

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A field experiment was conducted in a newly reclaimed soil at El-Saff region, El-Giza Governorate, Egypt to study the effects of different rates of nitrogen (N;62 to 248 kg ha-1) with or without soil inoculation of sulfur (S) oxidizing bacteria (SoxB), and combined inoculation of SoxB and N fixing b...

  14. Prediction of the production of nitrogen oxide (NOx) in turbojet engines

    NASA Astrophysics Data System (ADS)

    Tsague, Louis; Tsogo, Joseph; Tatietse, Thomas Tamo

    Gaseous nitrogen oxides (NO+NO2=NOx) are known as atmospheric trace constituent. These gases remain a big concern despite the advances in low NOx emission technology because they play a critical role in regulating the oxidization capacity of the atmosphere according to Crutzen [1995. My life with O 3, NO x and other YZO x S; Nobel Lecture; Chemistry 1995; pp 195; December 8, 1995] . Aircraft emissions of nitrogen oxides ( NOx) are regulated by the International Civil Aviation Organization. The prediction of NOx emission in turbojet engines by combining combustion operational data produced information showing correlation between the analytical and empirical results. There is close similarity between the calculated emission index and experimental data. The correlation shows improved accuracy when the 2124 experimental data from 11 gas turbine engines are evaluated than a previous semi empirical correlation approach proposed by Pearce et al. [1993. The prediction of thermal NOx in gas turbine exhausts. Eleventh International Symposium on Air Breathing Engines, Tokyo, 1993, pp. 6-9]. The new method we propose predict the production of NOx with far more improved accuracy than previous methods. Since a turbojet engine works in an atmosphere where temperature, pressure and humidity change frequently, a correction factor is developed with standard atmospheric laws and some correlations taken from scientific literature [Swartwelder, M., 2000. Aerospace engineering 410 Term Project performance analysis, November 17, 2000, pp. 2-5; Reed, J.A. Java Gas Turbine Simulator Documentation. pp. 4-5]. The new correction factor is validated with experimental observations from 19 turbojet engines cruising at altitudes of 9 and 13 km given in the ICAO repertory [Middleton, D., 1992. Appendix K (FAA/SETA). Section 1: Boeing Method Two Indices, 1992, pp. 2-3]. This correction factor will enable the prediction of cruise NOx emissions of turbojet engines at cruising speeds. The ICAO

  15. Effect of nitrogen source on growth and trichloroethylene degradation by methane-oxidizing bacteria

    SciTech Connect

    Chu, K.H.; Alvarez-Cohen, L.

    1998-09-01

    The effect of nitrogen source on methane-oxidizing bacteria with respect to cellular growth and trichloroethylene (TCE) degradation ability were examined. One mixed chemostat culture and two pure type II methane-oxidizing strains, Methylosinus trichosporium OB3b and strain CAC-2, which was isolated from the chemostat culture, were used in this study. All cultures were able to grow with each of three different nitrogen sources: ammonia, nitrate, and molecular nitrogen. Both M. trichosporium OB3b and strain CAC-2 showed slightly lower net cellular growth rates and cell yields but exhibited higher methane uptake rates, levels of poly-{beta}-hydroxybutyrate (PHB) production, and naphthalene oxidation rates when grown under nitrogen-fixing conditions. The TCE-degrading ability of each culture was measured in terms of initial TCE oxidation rates and TCE transformation capacities, measured both with and without external energy sources. Higher initial TCE oxidation rates and TCE transformation capacities were observed in nitrogen-fixing mixed, M. trichosporium OB3b, and CAC-2 cultures than in nitrate- or ammonia-supplied cells. TCE transformation capacities were found to correlate with cellular PHB content in all three cultures. The results of this study suggest that the nitrogen-fixing capabilities of methane-oxidizing bacteria can be used to select for high-activity TCE degraders for the enhancement of bioremediation in fixed-nitrogen-limited environments.

  16. Synthesis of antimony-doped tin oxide (ATO) nanoparticles by the nitrate-citrate combustion method

    SciTech Connect

    Zhang Jianrong; Gao Lian . E-mail: Liangaoc@online.sh.cn

    2004-12-02

    Antimony-doped tin oxide (ATO) nanoparticles having rutile structure have been synthesized by the combustion method using citric acid (CA) as fuel and nitrate as an oxidant, the metal sources were granulated tin and Sb{sub 2}O{sub 3}. The influence of citric acid (fuel) to metal ratio on the average crystallite size, specific surface area and morphology of the nanoparticles has been investigated. X-ray diffraction showed the tin ions were reduced to elemental tin during combustion reaction. The average ATO crystallite size increased with the increase of citric acid (fuel). Powder morphology and the comparison of crystallite size and grain size shows that the degree of agglomeration of the powder decreased with an increase of the ratio. The highest specific surface area was 37.5 m{sup 2}/g when the citric acid to tin ratio was about 6.

  17. TOTAL NITROGEN DEPOSITION (WET+DRY) FROM THE ATMOSHERE

    EPA Science Inventory

    Oxides of Nitrogen are emitted primarily as by-products of combustion. Sources include power plants, industrial boilers, and automobiles. In addition, agricultural fertilization and concentrated animal feeding operations (CAFOs) also release Amonium into the air. All these com...

  18. TOTAL NITROGEN DEPOSITION (WET+DRY) FROM THE ATMOSHERE (FUTURE)

    EPA Science Inventory

    Oxides of Nitrogen are emitted primarily as by-products of combustion. Sources include power plants, industrial boilers, and automobiles. In addition, agricultural fertilization and concentrated animal feeding operations (CAFOs) also release Amonium into the air. All these com...

  19. Theoretical studies of oxides relevant to the combustion of fossil fuels

    NASA Astrophysics Data System (ADS)

    Hicks, Jason Michael

    : adsorption isotherms, Gibbs free energy, enthalpy, entropy and desorption free energy. It was found that, when the maximum loading was compared to the regeneration costs, IRMOF-10 had the best performance, followed by IRMOF-8 then IRMOF-1. During the combustion of coal, not only is CO2 produced, but also the trace elements of arsenic and selenium escape into the environment though this process. Both arsenic and selenium are known to have a harmful effects on the environment and human health. Arsenic is also known to poison the catalytic converter used in selective catalytic reduction of NOx . These trace elements have been found on fly ash or in the hot flue gases released into the atmosphere. In flue gases they most often exist as oxides. There have been many experimental and a few theoretical studies on the monomeric oxides, AsOx and SeOx, where x = 1, 2, or 3. However, little is known concerning the corresponding dimeric oxides, As2Ox and Se2Ox, where x = 3 or 5, though these compounds are expected from their similarities to nitrogen and sulfur chemistry, respectively. From an experimental perspective, they are very challenging to study due to the high temperatures, complex environments and low concentrations needed for a direct study of the form and structures of the dimeric oxides. From a theoretical perspective, they can be challenging to study due to their multireference character and the need for both dynamic and non-dynamic electron correlation due to bonds forming and breaking during isomerization. However, high level multireference ab initio methods which account for both dynamic and non-dynamic electron correlation can be used. In the work contained in this thesis, GVVPT2 and CR-CC(2,3) were used to study the relative stabilities of all relevant isomers and transition states of As2Ox and Se2Ox. The structures used where generated through DFT using the B3LYP functional. Not only were plausible stationary points located for all species, it was further confirmed

  20. Theoretical studies of oxides relevant to the combustion of fossil fuels

    NASA Astrophysics Data System (ADS)

    Hicks, Jason Michael

    : adsorption isotherms, Gibbs free energy, enthalpy, entropy and desorption free energy. It was found that, when the maximum loading was compared to the regeneration costs, IRMOF-10 had the best performance, followed by IRMOF-8 then IRMOF-1. During the combustion of coal, not only is CO2 produced, but also the trace elements of arsenic and selenium escape into the environment though this process. Both arsenic and selenium are known to have a harmful effects on the environment and human health. Arsenic is also known to poison the catalytic converter used in selective catalytic reduction of NOx . These trace elements have been found on fly ash or in the hot flue gases released into the atmosphere. In flue gases they most often exist as oxides. There have been many experimental and a few theoretical studies on the monomeric oxides, AsOx and SeOx, where x = 1, 2, or 3. However, little is known concerning the corresponding dimeric oxides, As2Ox and Se2Ox, where x = 3 or 5, though these compounds are expected from their similarities to nitrogen and sulfur chemistry, respectively. From an experimental perspective, they are very challenging to study due to the high temperatures, complex environments and low concentrations needed for a direct study of the form and structures of the dimeric oxides. From a theoretical perspective, they can be challenging to study due to their multireference character and the need for both dynamic and non-dynamic electron correlation due to bonds forming and breaking during isomerization. However, high level multireference ab initio methods which account for both dynamic and non-dynamic electron correlation can be used. In the work contained in this thesis, GVVPT2 and CR-CC(2,3) were used to study the relative stabilities of all relevant isomers and transition states of As2Ox and Se2Ox. The structures used where generated through DFT using the B3LYP functional. Not only were plausible stationary points located for all species, it was further confirmed

  1. Evaluation of Nitrogen Oxides Emissions over California in Spring 2010

    NASA Astrophysics Data System (ADS)

    Huang, M.; Bowman, K. W.; Carmichael, G. R.; Chai, T.; Pierce, R.; Pollack, I. B.; Ryerson, T. B.

    2013-12-01

    Nitrogen Dioxide (NO2) belongs to the regulated 'six common air pollutants' by the US Environmental Protection Agency (EPA), due to its adverse impacts on the human respiratory system. It is also often used as the indicator for the highly reactive group of gases nitrogen oxides (NOx), the important ozone precursors. We model California air quality during the NOAA CalNex field campaign period in May 2010 using the STEM chemical transport model on a 12 km horizontal resolution grid. Three different anthropogenic emission inventories were used in the simulations: 1) 2005 National Emission Inventory (NEI 2005); 2) daily-varying emissions recently developed by California Air Resources Board (CARB); and 3) NEI 2008. The model-simulated NO2 were compared with the measurements by aircraft and the Ozone Monitoring Instrument (OMI) on board of the Aura satellite. We further conduct NO2 emission inversion using the four-dimensional variational approach [Chai et al., 2009] and the OMI NO2 column data. The inversion generated grid-based emission scaling factors on the NEI 2005, and the resulting NOx fields were 'cross-validated' by comparing with aircraft NO2 measurements. The adjustment on original emissions was then compared with 1) the CARB-documented NOx emission trends, 2) other 'top-down' estimates of California NOx emissions using aircraft measurements [Brioude et al., 2013], and 3) the space-observed NO2 column trends [Russell et al., 2012]. References Chai, T., Carmichael, G., Tang, Y., and Sandu, A., Regional NO2 emission inversion through four-dimensional variational approach using Sciamachy tropospheric column observations, Atmos. Environ., 43, 5046-5055, 2009. Brioude, J., Angevine, W. M., Ahmadov, R., Kim, S.-W., Evan, S., McKeen, S. A., Hsie, E.-Y., Frost, G. J., Neuman, J. A., Pollack, I. B., Peischl, J., Ryerson, T. B., Holloway, J., Brown, S. S., Nowak, J. B., Roberts, J. M., Wofsy, S. C., Santoni, G. W., Oda, T., and Trainer, M.: Top-down estimate of surface

  2. Ammonia Nitrogen Transformations in a Reactor with Aggregate made of Sewage Sludge Combustion Fly Ash.

    PubMed

    Rodziewicz, Joanna; Mielcarek, Artur; Janczukowicz, Wojciech; Białowiec, Andrzej; Gotkowska-Płachta, Anna; Proniewicz, Marcin

    2016-08-01

    The influence of light weight aggregate made of fly ash from sewage sludge thermal treatment (FASSTT LWA) on ammonia nitrogen metabolism, and on quantitative and qualitative changes of microorganisms colonizing the filling, was investigated. Two reactors were used in the experiment. The first was filled with gravel, the other with FASSTT LWA. The reactors were operated with a wastewater hydraulic loading rate of 5 mm(3) mm(-2) d(-1). During the eleven-week experiment, high efficiency of ammonia removal was observed. The lower concentrations of nitrites and nitrates in the effluent indicate that ammonia nitrogen removal resulted not just from nitrification. Nitrate concentration increase was reflected in a decrease in nitrogen removal efficiency. One possible explanation for this phenomenon is that in the period when ammonia nitrogen and nitrites were present in the reactor's FASSTT LWA filling, facilitating conditions occurred for the deammonification process. PMID:27456142

  3. Nitrogen oxide cycle regulates nitric oxide levels and bacterial cell signaling

    PubMed Central

    Sasaki, Yasuyuki; Oguchi, Haruka; Kobayashi, Takuya; Kusama, Shinichiro; Sugiura, Ryo; Moriya, Kenta; Hirata, Takuya; Yukioka, Yuriya; Takaya, Naoki; Yajima, Shunsuke; Ito, Shinsaku; Okada, Kiyoshi; Ohsawa, Kanju; Ikeda, Haruo; Takano, Hideaki; Ueda, Kenji; Shoun, Hirofumi

    2016-01-01

    Nitric oxide (NO) signaling controls various metabolic pathways in bacteria and higher eukaryotes. Cellular enzymes synthesize and detoxify NO; however, a mechanism that controls its cellular homeostasis has not been identified. Here, we found a nitrogen oxide cycle involving nitrate reductase (Nar) and the NO dioxygenase flavohemoglobin (Fhb), that facilitate inter-conversion of nitrate, nitrite, and NO in the actinobacterium Streptomyces coelicolor. This cycle regulates cellular NO levels, bacterial antibiotic production, and morphological differentiation. NO down-regulates Nar and up-regulates Fhb gene expression via the NO-dependent transcriptional factors DevSR and NsrR, respectively, which are involved in the auto-regulation mechanism of intracellular NO levels. Nitrite generated by the NO cycles induces gene expression in neighboring cells, indicating an additional role of the cycle as a producer of a transmittable inter-cellular communication molecule. PMID:26912114

  4. Nitrogen oxide cycle regulates nitric oxide levels and bacterial cell signaling.

    PubMed

    Sasaki, Yasuyuki; Oguchi, Haruka; Kobayashi, Takuya; Kusama, Shinichiro; Sugiura, Ryo; Moriya, Kenta; Hirata, Takuya; Yukioka, Yuriya; Takaya, Naoki; Yajima, Shunsuke; Ito, Shinsaku; Okada, Kiyoshi; Ohsawa, Kanju; Ikeda, Haruo; Takano, Hideaki; Ueda, Kenji; Shoun, Hirofumi

    2016-01-01

    Nitric oxide (NO) signaling controls various metabolic pathways in bacteria and higher eukaryotes. Cellular enzymes synthesize and detoxify NO; however, a mechanism that controls its cellular homeostasis has not been identified. Here, we found a nitrogen oxide cycle involving nitrate reductase (Nar) and the NO dioxygenase flavohemoglobin (Fhb), that facilitate inter-conversion of nitrate, nitrite, and NO in the actinobacterium Streptomyces coelicolor. This cycle regulates cellular NO levels, bacterial antibiotic production, and morphological differentiation. NO down-regulates Nar and up-regulates Fhb gene expression via the NO-dependent transcriptional factors DevSR and NsrR, respectively, which are involved in the auto-regulation mechanism of intracellular NO levels. Nitrite generated by the NO cycles induces gene expression in neighboring cells, indicating an additional role of the cycle as a producer of a transmittable inter-cellular communication molecule. PMID:26912114

  5. Catalytic combustion of soot over ceria-zinc mixed oxides catalysts supported onto cordierite.

    PubMed

    Nascimento, Leandro Fontanetti; Martins, Renata Figueredo; Silva, Rodrigo Ferreira; Serra, Osvaldo Antonio

    2014-03-01

    Modified substrates as outer heterogeneous catalysts was employed to reduce the soot generated from incomplete combustion of diesel or diesel/biodiesel blends, a process that harms the environment and public health. The unique storage properties of ceria (CeO2) makes it one of the most efficient catalysts available to date. Here, we proposed that ceria-based catalysts can lower the temperature at which soot combustion occurs; more specifically, from 610°C to values included in the diesel exhausts operation range (300-450°C). The sol-gel method was used to synthesize mixed oxide-based catalysts (CeO2:ZnO); the resulting catalysts were deposited onto cordierite substrates. In addition, the morphological and structural properties of the material were evaluated by XRD, BET, TPR-H2, and SEM. Thermogravimetric (TG/DTA) analysis revealed that the presence of the catalyst decreased the soot combustion temperature by 200°C on average, indicating that the oxygen species arise at low temperatures in this situation, promoting highly reactive oxidation reactions. Comparative analysis of soot emission by diffuse reflectance spectroscopy (DRS) showed that catalyst-impregnated cordierite samples efficiently oxidized soot in a diesel/biodiesel stationary motor: soot emission decreased by more than 70%. PMID:25079283

  6. Draft Plan for Development of the Integrated Science Assessment for Nitrogen Oxides - Health Criteria

    EPA Science Inventory

    EPA has announced a draft development plan for the next Integrated Science Assessment (ISA) for the health effects of nitrogen oxides (NOX) which will serve as the scientific basis for review of the primary (health-based) National Ambient Air Quality Standard for nitrogen dioxide...

  7. 78 FR 27374 - Workshop To Review Initial Draft Materials for the Nitrogen Oxides (NOX

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-10

    ...As part of the review of the air quality criteria for nitrogen oxides (NOX) and primary (health-based) National Ambient Air Quality Standards (NAAQS) for nitrogen dioxide (NO2), EPA is announcing a workshop to evaluate preliminary draft materials that will inform the development of the NOX Integrated Science Assessment (ISA) for health effects. The workshop is......

  8. 40 CFR 86.223-94 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 19 2013-07-01 2013-07-01 false Oxides of nitrogen analyzer calibration. 86.223-94 Section 86.223-94 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... nitrogen analyzer calibration. The provisions of § 86.123-78 apply to this subpart if NOX measurements...

  9. 40 CFR 86.223-94 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Oxides of nitrogen analyzer calibration. 86.223-94 Section 86.223-94 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... nitrogen analyzer calibration. The provisions of § 86.123-78 apply to this subpart if NOX measurements...

  10. 40 CFR 86.223-94 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 19 2012-07-01 2012-07-01 false Oxides of nitrogen analyzer calibration. 86.223-94 Section 86.223-94 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... nitrogen analyzer calibration. The provisions of § 86.123-78 apply to this subpart if NOX measurements...

  11. 40 CFR 86.223-94 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 18 2011-07-01 2011-07-01 false Oxides of nitrogen analyzer calibration. 86.223-94 Section 86.223-94 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... nitrogen analyzer calibration. The provisions of § 86.123-78 apply to this subpart if NOX measurements...

  12. The reaction of hydrogen peroxide with nitrogen dioxide and nitric oxide.

    NASA Technical Reports Server (NTRS)

    Gray, D.; Lissi, E.; Heicklen, J.

    1972-01-01

    The reactions were studied with the aid of a mass spectrometer. A pinhole bleed system provided continuous sampling of the gas mixture in the cell during the reaction. It was found that the homogeneous reactions of nitric oxide and nitrogen dioxide with hydrogen peroxide are too slow to be of any significance in the upper atmosphere. However, the heterogeneous reactions may be important in the conversion of nitric oxide to nitrogen dioxide in the case of polluted urban atmospheres.

  13. Sulfur dioxide and nitrogen oxides emissions from U.S. pulp and paper mills, 1980-2005.

    PubMed

    Pinkerton, John E

    2007-08-01

    Comprehensive surveys conducted at 5-yr intervals were used to estimate sulfur dioxide (SO,) and nitrogen oxides (NO.) emissions from U.S. pulp and paper mills for 1980, 1985, 1990, 1995, 2000, and 2005. Over the 25-yr period, paper production increased by 50%, whereas total SO, emissions declined by 60% to 340,000 short tons (t) and total NO, emissions decreased approximately 15% to 230,000 t. The downward emission trends resulted from a combination of factors, including reductions in oil and coal use, steadily declining fuel sulfur content, lower pulp and paper production in recent years, increased use of flue gas desulfurization systems on boilers, growing use of combustion modifications and add-on control systems to reduce boiler and gas turbine NO, emissions, and improvements in kraft recovery furnace operations. PMID:17824280

  14. Nitrogen loss by anaerobic oxidation of ammonium in rice rhizosphere

    PubMed Central

    Nie, San'an; Li, Hu; Yang, Xiaoru; Zhang, Zhaoji; Weng, Bosen; Huang, Fuyi; Zhu, Gui-Bing; Zhu, Yong-Guan

    2015-01-01

    Anaerobic oxidation of ammonium (anammox) is recognized as an important process for nitrogen (N) cycling, yet its role in agricultural ecosystems, which are intensively fertilized, remains unclear. In this study, we investigated the presence, activity, functional gene abundance and role of anammox bacteria in rhizosphere and non-rhizosphere paddy soils using catalyzed reporter deposition–fluorescence in situ hybridization, isotope-tracing technique, quantitative PCR assay and 16S rRNA gene clone libraries. Results showed that rhizosphere anammox contributed to 31–41% N2 production with activities of 0.33–0.64 nmol N2 g−1 soil h−1, whereas the non-rhizosphere anammox bacteria contributed to only 2–3% N2 production with lower activities of 0.08–0.26 nmol N2 g−1 soil h−1. Higher anammox bacterial cells were observed (0.75–1.4 × 107 copies g−1 soil) in the rhizosphere, which were twofold higher compared with the non-rhizosphere soil (3.7–5.9 × 106 copies g−1 soil). Phylogenetic analysis of the anammox bacterial 16S rRNA genes indicated that two genera of ‘Candidatus Kuenenia' and ‘Candidatus Brocadia' and the family of Planctomycetaceae were identified. We suggest the rhizosphere provides a favorable niche for anammox bacteria, which are important to N cycling, but were previously largely overlooked. PMID:25689022

  15. Oxidation of Reactive Nitrogen and Ozone Production in Tokyo

    NASA Astrophysics Data System (ADS)

    Fukuda, M.; Kondo, Y.; Miyazaki, Y.; Morino, Y.; Takegawa, N.; Miyakawa, T.; Komazaki, Y.; Tanimoto, H.; Yokouchi, Y.; Kanaya, Y.; McKenzie, R.; Johnston, P.

    2005-12-01

    Ground based measurements of NOx (NO + NO2), nitric acid (HNO3), particulate nitrate (NO3-), peroxyacyl nitrates (PANs), and total reactive nitrogen (NOy) were conducted in Tokyo in winter (January-February 2004), summer (July-August 2003 and 2004), and fall (October 2003). Carbon monoxide (CO), ozone (O3), non-methane hydrocarbons (NMHCs) and actinic flux were also measured during these periods. Average mixing ratios of these species and the NOx/NOy, HNO3/NOy, NO3-/NOy, and PANs/NOy ratios showed distinct diurnal-seasonal variations. The NOx/NOy ratios were 0.63-0.95 on high J(O1D) days, and 0.77-0.94 on low J(O1D) days. In summer and winter, total nitrate (TN = HNO3 + NO3-) was the dominant form of the NOx oxidation products (NOz = NOy - NOx) during the daytime on high J(O1D) days, and PANs were minor component species. The partitioning of TN was controlled mainly by temperature and the shit of the partitioning to NO3- at low temperature suppressed removal of NOy by dry deposition of HNO3. Removal rate of NOy is estimated using CO as a tracer. The estimated loss of NOy (LNOy) was largest during the daytime in summer (35%), while smallest (0%) in winter. The corrected ozone production efficiency (OPEx), which is defined as the linear regression slope of the observed Ox (= O3 + NO2) versus NOz* (= NOz + LNOy), is estimated to be 2.5. The estimated OPEx is slightly lower than those obtained in the U.S. urban air, which is probably due to lower ratios of NMHCs to NOx in this study. Possible factors controlling the OPEx will be discussed in detail.

  16. Pyrolysis and Combustion of Acetonitrile (CH{sub 3}CN)

    SciTech Connect

    Britt, P.F.

    2002-05-22

    Acetonitrile (CH{sub 3}CN) is formed from the thermal decomposition of a variety of cyclic, noncyclic, and polymeric nitrogen-containing compounds such as pyrrole and polyacrylonitrile. The pyrolysis and combustion of acetonitrile have been studied over the past 30 years to gain a more detailed understanding of the complex mechanisms involved in the release of nitrogen-containing compounds such as hydrogen cyanide (HCN) in fires and nitrogen oxides (NOx) in coal combustion. This report reviews the literature on the formation of HCN and NOx from the pyrolysis and combustion of acetonitrile and discusses the possible products found in an acetonitrile fire.

  17. Analytical study of mechanisms for nitric oxide formation during combustion of methane in a jet-stirred combustor

    NASA Technical Reports Server (NTRS)

    Jachimowski, C. J.

    1975-01-01

    The role of chemical kinetics in the formation of nitric oxide during the combustion of methane was examined analytically by means of a detailed chemical mechanism for the oxidation of methane, for the reaction between hydrocarbon fragments, and for the formation of nitric oxide. By comparing predicted nitric oxide levels with values reported in the literature from jet-stirred combuster experiments, it was determined that the nitric oxide levels observed in fuel-rich flames cannot be described by a mechanism in which the rate of nitric oxide formation is controlled solely by the kinetics of oxygen atom formation. A proposed mechanism for the formation of nitric oxide in methane-rich flames reproduces the observed levels. The oxidation of hydrogen cyanide appears to be an important factor in nitric oxide formation.

  18. Photocatalytic oxidation of nitrogen oxides using TiO2 loading on woven glass fabric.

    PubMed

    Wang, Haiqiang; Wu, Zhongbiao; Zhao, Weirong; Guan, Baohong

    2007-01-01

    TiO2 loading on woven glass fabric is applied to treat nitrogen oxides (NOx) by photocatalytic oxidation (PCO). In this paper, the PCO behavior of NO at high concentrations was studied by PCO of NOx at source levels (20-168 ppm). The PCO efficiency reached 27% in this experiment, while the inlet NOx concentration was 168 ppm (147 ppm NO). The dependency of the reaction rate on several key influencing factors (relative humidity, space time, inlet concentration, oxygen percentage) was also studied. The results illustrate that the resulting hydroxyl radical and active oxide play an important role in the oxidation of NOx. The reactions are limited by the thermodynamic equilibrium after ca. 15s space time. A possible explanation for the catalyst deactivation is the accumulation of nitric acid and nitrous acid on the TiO2 surface during the PCO of NOx. However, the photocatalytic activity can be recovered with a simple heat treatment. The results from the study of the effect of the inlet concentration were described with the Langmuir-Hinshelwood model. PMID:16806397

  19. Role of char during reburning of nitrogen oxides. First quarterly report, October 1, 1993--December 31, 1993

    SciTech Connect

    Chen, Wei-Yin

    1993-12-31

    Customarily, coal and lignite have not been considered viable reburning fuels for a number of reasons. NO reduction through homogeneous gas phase mechanisms is generally believed more important than the heterogeneous NO reduction on char; and coal devolatilization in the fuel rich environment generates only about 50% of the volatile hydrocarbon radicals than gaseous hydrocarbons under the same fuel-to-oxidant stoichiometry. In addition, the fuel nitrogen could result in additional nitrogen oxide emissions in the burnout stage. What has not been anticipated is the highly active nature of lignite char surface. First, it has been demonstrated in the literature that lignite char can be gasified by nitrogen oxide; second, the minerals in lignite char can catalyze the CO + NO and gasification reaction; and third, lignite char has a highly porous structure which is desirable for gas/solid reactions. The unique NO activity on char surface is expected to benefit the utilities which are involved in coal combustion and have to meet the stringent Clean Air Act Amendments of 1990. This program is aimed at a better understanding of the chemical and physical mechanisms involved in the reburning with chars. Char gasification rates will be measured with and without the presence of CO. Further, the rate of the char catalyzed CO + NO reaction will also be measured. Experiments have been conducted with a flow reactor which simulates the reburning stage. One bituminous coal and two lignites, one from North Dakota and the other from Mississippi, are used in these tasks. A unique component of this program is the use of the fractal concept in the estimations of these gas/solid reaction rates. The proposed program is designed to investigate the relative importance of these two reactions (char gasification and ash catalyzed CO + NO reactions) under reburning conditions.

  20. Evaluation of a Colorimetric Personal Dosimeter for Nitrogen Oxide.

    ERIC Educational Resources Information Center

    Diamond, Philip

    A personal colorimetric dosimeter for nitrogen dioxide was developed. Tests were performed to determine the response of these strips to various concentrations of NO2. The dosimeter strips were satisfactory for approximate determinations of total exposure (concentration + time) of nitrogen dioxide. The total exposure was calculated in terms of time…

  1. Modelling land atmosphere exchange of gaseous oxides of nitrogen in Europe

    NASA Astrophysics Data System (ADS)

    Duyzer, Jan; Fowler, David

    1994-11-01

    Nitrogen oxides in ambient air in industrial countries result mainly from emissions of nitric oxide (NO) from fossil fuel combustion. In the presence of ozone (O3), NO is rapidly converted into nitrogen dioxide (NO2). Further oxidation of NO2 leads to the formation of a range of compounds, the most important of which are: nitric acid (HNO3), peroxy acetyl nitrate (PAN) and nitrous acid (HNO2). The environmental effects of these compounds include eutrophication of natural ecosystems, acidification and photochemical air pollution. It is therefore necessary to understand the dry deposition processes for these compounds and use this understanding to provide estimates of dry deposition inputs to ecosystems across Europe. This review outlines current understanding of the exchange processes and methods used to estimate regional NOy deposition. Several methods have been used to measure dry deposition. Among these micrometeorological methods provide the best approach for estimating fluxes in the field. However, few field measurements of the deposition velocity of NO2 to important ecosystems have been reported and the results have not always been conclusive. Measurement artefacts such as non-stationarity caused by local sources, monitors responding to other gases than NO2 and the influence of photochemical reactions have made field measurement very difficult. More recent field work however has provided strong indications that NO2 deposition to vegetation is controlled by stomatal opening. This implies that the deposition velocity shows a marked diurnal as well as an annual cycle with maximum values up to 1cm s-1 during the day in the summer. Few measurements of HNO2 exchange have been reported, but based on knowledge of its physical-chemical properties it is expected that HNO2 is taken up via stomata. Measurements of PAN also indicate uptake controlled by stomatal opening. Several

  2. 40 CFR 52.34 - Action on petitions submitted under section 126 relating to emissions of nitrogen oxides.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... section 126 relating to emissions of nitrogen oxides. 52.34 Section 52.34 Protection of Environment... of nitrogen oxides. (a) Definitions. For purposes of this section, the following definitions apply... of nitrogen. (6) OTAG means the Ozone Transport Assessment Group (active 1995-1997), a national...

  3. 40 CFR 52.34 - Action on petitions submitted under section 126 relating to emissions of nitrogen oxides.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... section 126 relating to emissions of nitrogen oxides. 52.34 Section 52.34 Protection of Environment... of nitrogen oxides. (a) Definitions. For purposes of this section, the following definitions apply... of nitrogen. (6) OTAG means the Ozone Transport Assessment Group (active 1995-1997), a national...

  4. 40 CFR 60.46b - Compliance and performance test methods and procedures for particulate matter and nitrogen oxides.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... and procedures for particulate matter and nitrogen oxides. 60.46b Section 60.46b Protection of... nitrogen oxides. (a) The PM emission standards and opacity limits under § 60.43b apply at all times except... oil having a nitrogen content greater than 0.30 weight percent shall determine compliance with the...

  5. 40 CFR 52.34 - Action on petitions submitted under section 126 relating to emissions of nitrogen oxides.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... section 126 relating to emissions of nitrogen oxides. 52.34 Section 52.34 Protection of Environment... of nitrogen oxides. (a) Definitions. For purposes of this section, the following definitions apply... of nitrogen. (6) OTAG means the Ozone Transport Assessment Group (active 1995-1997), a national...

  6. 40 CFR 52.34 - Action on petitions submitted under section 126 relating to emissions of nitrogen oxides.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... section 126 relating to emissions of nitrogen oxides. 52.34 Section 52.34 Protection of Environment... of nitrogen oxides. (a) Definitions. For purposes of this section, the following definitions apply... of nitrogen. (6) OTAG means the Ozone Transport Assessment Group (active 1995-1997), a national...

  7. 40 CFR 60.46b - Compliance and performance test methods and procedures for particulate matter and nitrogen oxides.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... and procedures for particulate matter and nitrogen oxides. 60.46b Section 60.46b Protection of... nitrogen oxides. (a) The PM emission standards and opacity limits under § 60.43b apply at all times except... oil having a nitrogen content greater than 0.30 weight percent shall determine compliance with the...

  8. 40 CFR 60.46b - Compliance and performance test methods and procedures for particulate matter and nitrogen oxides.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... and procedures for particulate matter and nitrogen oxides. 60.46b Section 60.46b Protection of... nitrogen oxides. (a) The PM emission standards and opacity limits under § 60.43b apply at all times except... oil having a nitrogen content greater than 0.30 weight percent shall determine compliance with the...

  9. 40 CFR 52.34 - Action on petitions submitted under section 126 relating to emissions of nitrogen oxides.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... section 126 relating to emissions of nitrogen oxides. 52.34 Section 52.34 Protection of Environment... of nitrogen oxides. (a) Definitions. For purposes of this section, the following definitions apply... of nitrogen. (6) OTAG means the Ozone Transport Assessment Group (active 1995-1997), a national...

  10. 40 CFR 60.46b - Compliance and performance test methods and procedures for particulate matter and nitrogen oxides.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... and procedures for particulate matter and nitrogen oxides. 60.46b Section 60.46b Protection of... nitrogen oxides. (a) The PM emission standards and opacity limits under § 60.43b apply at all times except... oil having a nitrogen content greater than 0.30 weight percent shall determine compliance with the...

  11. Process for the catalytic reduction of nitrogen oxides in gaseous mixtures

    SciTech Connect

    Ginger, E.A.

    1981-05-19

    A process for the reductive removal of a nitrogen oxide from a gaseous stream, particularly a stream containing oxygen, water, sulfur dioxide, nitrogen oxide and nitrogen, by contacting the stream with ammonia in the presence of a mixture of two catalysts. The first catalyst comprises copper or a copper compound, preferably copper sulfate supported on a porous carrier material. The second catalyst is a combination of metals or compounds thereof, preferably sulfates of vanadium and iron or tungsten and iron, also dispersed on a porous carrier material.

  12. Nitrogen-doped carbon nanotube as a potential metal-free catalyst for CO oxidation.

    PubMed

    Lin, I-Hsiang; Lu, Yu-Huan; Chen, Hsin-Tsung

    2016-04-28

    We elucidate the possibility of nitrogen-doped carbon nanotube as a robust catalyst for CO oxidation. We have performed first-principles calculations considering the spin-polarization effect to demonstrate the reaction of CO oxidation catalyzed by the nitrogen-doped carbon nanotube. The calculations show that O2 species can be partially reduced with charge transfer from the nitrogen-doped carbon nanotube and directly chemisorbed on the C-N sites of the nitrogen-doped carbon nanotube. The partially reduced O2 species at the C-N sites can further directly react with a CO molecule via the Eley-Rideal mechanism with the barriers of 0.45-0.58 eV for the different diameter of nanotube. Ab initio molecular dynamics (AIMD) simulations were performed and showed that the oxidation of CO occurs by the Eley-Rideal mechanism. The relationship between the curvature and reactivity of the nitrogen doped carbon nanotube was also unraveled. It appears that the barrier height of the rate-limiting step depends on the curvature of the nitrogen-doped carbon nanotube in the trend of (3,3)-NCNT < (4,4)-NCNT < (5,5)-NCNT (decreases with increased curvature). Using this relationship, we can predict the barriers for other N-doped carbon nanotubes with different tube diameters. Our results reveal that the nitrogen doped carbon nanomaterials can be a good, low-cost, and metal-free catalyst for CO oxidation. PMID:27074831

  13. Nitrogen oxide abatement by distributed fuel addition. [Reburning, mixing, effect of concentration of nitrogen

    SciTech Connect

    Wendt, J.O.L.; Mereb, J.B.

    1991-01-02

    Reburning experiments are presented in which the effect of the primary flame mode is examined. The application of reburning downstream of an axial diffusion primary flame without swirl is compared to reburning results in which the primary flame is premixed. The comparison is qualitative and is intended to examine reburning under more realistic conditions of utility boilers, where premixed flames are not common. Experimental results of reburning tests using nitrogen containing reburning fuels (ammonia doped natural gas and coal) are presented. The effect of reburning fuel type and nitrogen content on nitrogenous species profiles in the reburn zone are discussed. The last section is concerned with the applications of the kinetic model to predict overall reburning effectiveness from the primary NO level and to identify configuration for low total fixed nitrogen concentration. The effects of mixing in the early stage of reburning are examined and appropriate corrections are incorporated with the kinetic model to allow the prediction of nitrogenous species concentrations in the region where mixing effects are important. An empirical correlation is used to estimate the conversion of the total fixed nitrogen in the reburn zone to NO in the final stage of reburning. The kinetic model is also applied to the testing of hypothetical fuel-rich configurations to identify kinetic limits that would prevent further reductions in nitrogenous species.

  14. Carbohydrate-Assisted Combustion Synthesis To Realize High-Performance Oxide Transistors.

    PubMed

    Wang, Binghao; Zeng, Li; Huang, Wei; Melkonyan, Ferdinand S; Sheets, William C; Chi, Lifeng; Bedzyk, Michael J; Marks, Tobin J; Facchetti, Antonio

    2016-06-01

    Owing to high carrier mobilities, good environmental/thermal stability, excellent optical transparency, and compatibility with solution processing, thin-film transistors (TFTs) based on amorphous metal oxide semiconductors (AOSs) are promising alternatives to those based on amorphous silicon (a-Si:H) and low-temperature (<600 °C) poly-silicon (LTPS). However, solution-processed display-relevant indium-gallium-tin-oxide (IGZO) TFTs suffer from low carrier mobilities and/or inferior bias-stress stability versus their sputtered counterparts. Here we report that three types of environmentally benign carbohydrates (sorbitol, sucrose, and glucose) serve as especially efficient fuels for IGZO film combustion synthesis to yield high-performance TFTs. The results indicate that these carbohydrates assist the combustion process by lowering the ignition threshold temperature and, for optimal stoichiometries, enhancing the reaction enthalpy. IGZO TFT mobilities are increased to >8 cm(2) V(-1) s(-1) on SiO2/Si gate dielectrics with significantly improved bias-stress stability. The first correlations between precursor combustion enthalpy and a-MO densification/charge transport are established. PMID:27168054

  15. INFLUENCE OF COAL COMPOSITION ON THE FATE OF VOLATILE AND CHAR NITROGEN DURING COMBUSTION

    EPA Science Inventory

    The paper gives results of burning 50 coals from North America, Europe, Asia, South Africa, and Australia in a 21 kWt refactory-lined tunnel furnace to determine the influence of coal properties on the fate of volatile and char nitrogen. Excess-air fuel NO emissions (determined b...

  16. High temperature nitrogen oxides sensing enabled by indium oxide thin films

    NASA Astrophysics Data System (ADS)

    Kannan, Srinivasan

    Generation of power using fossil fuel combustion invariably results in formation of undesirable gas species (NOx, SOx, CO, CO2, etc.) at high-temperatures which are harmful to the environment. Thus, there is a continual need to develop sensitive, responsive, stable, selective, robust and low-cost sensor systems and sensor materials for combustion monitoring. This work investigates the viability of microfabricated NO x sensors based on sputtered indium oxide (In2O3) utilizing microhotplate structures. The material becomes resistive when exposed to oxidizing gases like NOx, with its conductivity dependent upon the temperature, partial pressure of the test gas and morphological structure. We believe this device would help increase efficiency and decrease emissions through improved combustion process control, leading to a comparably economic and responsive sensor. In this work, more than 600 sensors were fabricated and tested, including RF and pulsed-DC sputtered films. About 50 unique sensor conditions were characterized and related to the gas sensor response. The sensor conditions included deposition parameters (power, pressure, time, etc.) and postdeposition processes (anneals, promoter layers, etc.). In2O3 thin films were RF sputter deposited on microhotplate structures with different thickness (40 to 300 nm) in pure Ar. Additionally, a combination of reactive and RF sputtering of In2O3 material was-deposited in Ar and O2 (10% and 25%) mixture. In2O3 films without promoter layers and with gold or TiOx promoter layers (~ 3 nm) were investigated for NOx sensing. Selectivity, stability and repeatability of indium oxide (In2O3) thin film sensor to detect NOx (25 ppm) in presence of other exhaust gas pollutants including H2, NH3 and CO2 at high operating temperatures (greater than 350 °C) was investigated in N2 carrier gas. In2O 3 films (150nm thick) deposited in Ar and O2 (25% O 2) presented the highest response (S ~ 50) to 25 ppm NOx at 500 °C when compared to films

  17. Nitrogen oxide removal using diesel fuel and a catalyst

    DOEpatents

    Vogtlin, George E.; Goerz, David A.; Hsiao, Mark; Merritt, Bernard T.; Penetrante, Bernie M.; Reynolds, John G.; Brusasco, Ray

    2000-01-01

    Hydrocarbons, such as diesel fuel, are added to internal combustion engine exhaust to reduce exhaust NO.sub.x in the presence of a amphoteric catalyst support material. Exhaust NO.sub.x reduction of at least 50% in the emissions is achieved with the addition of less than 5% fuel as a source of the hydrocarbons.

  18. Effect of nitrogen doping on wetting and photoactive properties of laser processed zinc oxide-graphene oxide nanocomposite layers

    SciTech Connect

    György, E.; Pérez del Pino, A.; Logofatu, C.; Duta, A.; Isac, L.

    2014-07-14

    Zinc oxide-graphene oxide nanocomposite layers were submitted to laser irradiation in air or controlled nitrogen atmosphere using a frequency quadrupled Nd:YAG (λ = 266 nm, τ{sub FWHM} ≅ 3 ns, ν = 10 Hz) laser source. The experiments were performed in air at atmospheric pressure or in nitrogen at a pressure of 2 × 10{sup 4} Pa. The effect of the irradiation conditions, incident laser fluence value, and number of subsequent laser pulses on the surface morphology of the composite material was systematically investigated. The obtained results reveal that nitrogen incorporation improves significantly the wetting and photoactive properties of the laser processed layers. The kinetics of water contact angle variation when the samples are submitted to laser irradiation in nitrogen are faster than that of the samples irradiated in air, the surfaces becoming super-hydrophilic under UV light irradiation.

  19. Impact of coal combustion product amendments on soil quality. 1: Mobilization of soil organic nitrogen

    SciTech Connect

    Stuczynski, T.I. |; McCarty, G.W.; Wright, R.J.

    1998-12-01

    There is growing interest in the use of coal combustion products (fly ash and bed ash) at agronomic rates, based on the liming requirements of agricultural soils, and at higher rates in technologies for reclamation of degraded lands. There is concern, however, that excessive or other improper use may have a negative impact on soil quality and the environment. To determine the influence of potentially excessive rates of coal combustion products on the fate of soil quality and the environment. To determine the influence of potentially excessive rates coal combustion products on the fate of soil organic N and impacts on soil quality, the authors studied the effects of fly ash and bed ash applied at rates of 0, 20, 40, and 80 g kg{sup {minus}1} soil on the content of organic N in soils incubated for 10, 25, or 60 days. Studies comparing the influence of these products on the organic N content of the soil showed that although applications of fly ash had little influence on the fate of this N, application of bed ash caused substantial decreases in the total N content of water-extracted soil through the mobilization of organic N. Measurements of the changes in acid hydrolyzable N components of organic matter in soils treated with high rates of bed ash showed that within the first 10 days of incubation, losses of N in the forms of amino sugars, amino acids, and hydrolyzable NH{sub 4}{sup +} could account largely for losses of total N in bed ash-amended soils. Decreases in the amino acid content of soil organic matter accounted for most of these losses, and such decreases were directly related to increases in soil pH caused by the bed ash amendment.

  20. Modelling atmospheric oxidation of 2-aminoethanol (MEA) emitted from post-combustion capture using WRF-Chem.

    PubMed

    Karl, M; Svendby, T; Walker, S-E; Velken, A S; Castell, N; Solberg, S

    2015-09-15

    Carbon capture and storage (CCS) is a technological solution that can reduce the amount of carbon dioxide (CO2) emissions from the use of fossil fuel in power plants and other industries. A leading method today is amine based post-combustion capture, in which 2-aminoethanol (MEA) is one of the most studied absorption solvents. In this process, amines are released to the atmosphere through evaporation and entrainment from the CO2 absorber column. Modelling is a key instrument for simulating the atmospheric dispersion and chemical transformation of MEA, and for projections of ground-level air concentrations and deposition rates. In this study, the Weather Research and Forecasting model inline coupled with chemistry, WRF-Chem, was applied to quantify the impact of using a comprehensive MEA photo-oxidation sequence compared to using a simplified MEA scheme. Main discrepancies were found for iminoethanol (roughly doubled in the detailed scheme) and 2-nitro aminoethanol, short MEA-nitramine (reduced by factor of two in the detailed scheme). The study indicates that MEA emissions from a full-scale capture plant can modify regional background levels of isocyanic acid. Predicted atmospheric concentrations of isocyanic acid were however below the limit value of 1 ppbv for ambient exposure. The dependence of the formation of hazardous compounds in the OH-initiated oxidation of MEA on ambient level of nitrogen oxides (NOx) was studied in a scenario without NOx emissions from a refinery area in the vicinity of the capture plant. Hourly MEA-nitramine peak concentrations higher than 40 pg m(-3) did only occur when NOx mixing ratios were above 2 ppbv. Therefore, the spatial variability and temporal variability of levels of OH and NOx need to be taken into account in the health risk assessment. The health risk due to direct emissions of nitrosamines and nitramines from full-scale CO2 capture should be investigated in future studies. PMID:25958366

  1. Nitrogen doped TiO2 nano-particles: Phase control by solution combustion method

    NASA Astrophysics Data System (ADS)

    Bapna, Komal; Choudhary, R. J.; Phase, D. M.; Shastri, Sheetal; Prasad, R.; Ahuja, B. L.

    2016-05-01

    N-doped TiO2 nano powders were prepared by sol-gel solution combustion method. The influence of different fuels (urea and citric acid) used in obtaining N-TiO2 nano particles in similar conditions (heat treatment, amount of precursors) has been investigated. The growth of different phases of TiO2 (anatase and rutile) is strongly affected by the ligands and the dehydration reaction. Reduction in the band gap of TiO2 and features observed in the XPS spectra confirm the incorporation of N into TiO2 matrix.

  2. 40 CFR 52.136 - Control strategy for ozone: Oxides of nitrogen.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Control strategy for ozone: Oxides of... for ozone: Oxides of nitrogen. EPA is approving an exemption request submitted by the State of Arizona on April 13, 1994 for the Maricopa County ozone nonattainment area from the NOX RACT...

  3. 40 CFR 52.235 - Control strategy for ozone: Oxides of nitrogen.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Control strategy for ozone: Oxides of... for ozone: Oxides of nitrogen. EPA is approving an exemption request submitted by the Monterey Bay Unified Air Pollution Control District on April 26, 1994 for the Monterey Bay ozone nonattainment...

  4. 40 CFR 52.326 - Area-wide nitrogen oxides (NOX) exemptions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 3 2011-07-01 2011-07-01 false Area-wide nitrogen oxides (NOX... oxides (NOX) exemptions. The Denver Regional Council of Governments (DRCOG) submitted a NOX exemption... area, be exempted from the requirement to meet the NOX provisions of the Federal transportation...

  5. 40 CFR 52.326 - Area-wide nitrogen oxides (NOX) exemptions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Area-wide nitrogen oxides (NOX... oxides (NOX) exemptions. The Denver Regional Council of Governments (DRCOG) submitted a NOX exemption... area, be exempted from the requirement to meet the NOX provisions of the Federal transportation...

  6. Screen-printing of ferrite magnetic nanoparticles produced by carbon combustion synthesis of oxides

    NASA Astrophysics Data System (ADS)

    Martirosyan, Karen S.; Dannangoda, Chamath; Galstyan, Eduard; Litvinov, Dmitri

    2012-05-01

    The feasibility of screen-printing process of hard ferrite magnetic nanoparticles produced by carbon combustion synthesis of oxides (CCSO) is investigated. In CCSO, the exothermic oxidation of carbon generates a smolder thermal reaction wave that propagates through the solid reactant mixture converting it to the desired oxides. The complete conversion of hexaferrites occurs using reactant mixtures containing 11 wt. % of carbon. The BaFe12O19 and SrFe12O19 hexaferrites had hard magnetic properties with coercivity of 3 and 4.5 kOe, respectively. It was shown that the synthesized nanoparticles could be used to fabricate permanent magnet structures by consolidating them using screen-printing techniques.

  7. Quantifying the impact of nitric oxide calibration gas mixture oxidation on reported nitrogen dioxide concentrations

    NASA Astrophysics Data System (ADS)

    Sweeney, Bryan P.; Quincey, Paul G.; Green, David; Fuller, Gary W.

    2015-03-01

    Chemiluminescent analysers for measuring nitric oxide (NO) and nitrogen dioxide (NO2) in ambient air are generally calibrated with certified gas standard cylinders of NO in nitrogen. Verification of the NOx and NO amount fractions has been carried out on many such 'on-site' calibration cylinders at air quality monitoring stations. These measurements indicate that significant numbers of these gas mixtures have become somewhat degraded, with several percent of the NO oxidised to NO2. The effect of not compensating for this degradation on reported concentrations is discussed. If such degradation is not quantified and corrected for, there will be a systematic under-reporting of NO2 concentrations, which, due to the non-linearity of the effect, could reduce high reported NO2 concentrations at kerbside sites by around 20%. This could significantly reduce the number of reported exceedances of the NO2 limit value at such sites, compared to results obtained where there is no degradation of the NO cylinder.

  8. Experimental investigation on regulated and unregulated emissions of a diesel/methanol compound combustion engine with and without diesel oxidation catalyst.

    PubMed

    Zhang, Z H; Cheung, C S; Chan, T L; Yao, C D

    2010-01-15

    The use of methanol in combination with diesel fuel is an effective measure to reduce particulate matter (PM) and nitrogen oxides (NOx) emissions from in-use diesel vehicles. In this study, a diesel/methanol compound combustion (DMCC) scheme was proposed and a 4-cylinder naturally-aspirated direct-injection diesel engine modified to operate on the proposed combustion scheme. The effect of DMCC and diesel oxidation catalyst (DOC) on the regulated emissions of total hydrocarbons (THC), carbon monoxide (CO), NOx and PM was investigated based on the Japanese 13 Mode test cycle. Certain unregulated emissions, including methane, ethyne, ethene, 1,3-butadiene, BTX (benzene, toluene, xylene), unburned methanol and formaldehyde were also evaluated based on the same test cycle. In addition, the soluble organic fraction (SOF) in the particulate and the particulate number concentration and size distribution were investigated at certain selected modes of operation. The results show that the DMCC scheme can effectively reduce NOx, particulate mass and number concentrations, ethyne, ethene and 1,3-butadiene emissions but significantly increase the emissions of THC, CO, NO(2), BTX, unburned methanol, formaldehyde, and the proportion of SOF in the particles. After the DOC, the emission of THC, CO, NO(2), as well as the unregulated gaseous emissions, can be significantly reduced when the exhaust gas temperature is sufficiently high while the particulate mass concentration is further reduced due to oxidation of the SOF. PMID:19919875

  9. Relationship between peroxyacetyl nitrate and nitrogen oxides in the clean troposphere

    NASA Technical Reports Server (NTRS)

    Singh, H. B.; Salas, L. J.; Ridley, B. A.; Shetter, J. D.; Donahue, N. M.

    1985-01-01

    The first study is presented in which the mixing ratios of peroxyactyl nitrate (PAN) and nitrogen oxides, as well as those of peroxypropionyl nitrate and O3 and relevant meteorological parameters, were measured concurrently at a location that receives clean, continental air. The results show that, in clean conditions, nitrogen oxides present in the form of PAN can be as much or more abundant than the inorganic form. In addition, PAN can be an important source of peroxyacetyl radicals which may be important to oxidation processes in the gas as well as liquid phases.

  10. Estimating nitrogen oxides emissions at city scale in China with a nightlight remote sensing model.

    PubMed

    Jiang, Jianhui; Zhang, Jianying; Zhang, Yangwei; Zhang, Chunlong; Tian, Guangming

    2016-02-15

    Increasing nitrogen oxides (NOx) emissions over the fast developing regions have been of great concern due to their critical associations with the aggravated haze and climate change. However, little geographically specific data exists for estimating spatio-temporal trends of NOx emissions. In order to quantify the spatial and temporal variations of NOx emissions, a spatially explicit approach based on the continuous satellite observations of artificial nighttime stable lights (NSLs) from the Defense Meteorological Satellite Program/Operational Linescan System (DMSP/OLS) was developed to estimate NOx emissions from the largest emission source of fossil fuel combustion. The NSL based model was established with three types of data including satellite data of nighttime stable lights, geographical data of administrative boundaries, and provincial energy consumptions in China, where a significant growth of NOx emission has experienced during three policy stages corresponding to the 9th-11th)Five-Year Plan (FYP, 1995-2010). The estimated national NOx emissions increased by 8.2% per year during the study period, and the total annual NOx emissions in China estimated by the NSL-based model were approximately 4.1%-13.8% higher than the previous estimates. The spatio-temporal variations of NOx emissions at city scale were then evaluated by the Moran's I indices. The global Moran's I indices for measuring spatial agglomerations of China's NOx emission increased by 50.7% during 1995-2010. Although the inland cities have shown larger contribution to the emission growth than the more developed coastal cities since 2005, the High-High clusters of NOx emission located in Beijing-Tianjin-Hebei regions, the Yangtze River Delta, and the Pearl River Delta should still be the major focus of NOx mitigation. Our results indicate that the readily available DMSP/OLS nighttime stable lights based model could be an easily accessible and effective tool for achieving strategic decision making

  11. Nitrogen oxide stack sampling at the U.S. DOE Oak Ridge Y-12 Steam Plant

    SciTech Connect

    L.V. Gibson, jr.; M.P. Humphreys; J.M. Skinner

    2000-03-01

    On November 7, 1997, the EPA proposed a Nitrogen Oxides State Implementation Plan Call (NO{sub x} SIP Call) for 22 states in the Eastern US which included the state of Tennessee. This initial proposal was followed by proposed statewide NO{sub x} budgets in the May 11, 1998, Supplemental Notice of Proposed Rulemaking. In the development of the NO{sub x} SIP Call, EPA performed a number of air quality analyses and determined that NO{sub x} emissions from Tennessee should be reduced. Industrial boilers, turbines, stationary internal combustion engines, and cement manufacturing are the only non-electric generating unit sources for which reductions are assumed in the budget calculation. Emission reductions are required if specific source heat input capacity is greater than 250 million Btu per hour. The US Department of Energy (DOE) Oak Ridge Y-12 Steam Plant consists of four Wickes pulverized coal fired boilers each rated at a maximum heat input capacity of 298 million Btu per hour, and will therefore be impacted by these regulatory actions. Each boiler is equipped with two pulverizing mills. Coal or natural gas or a combination of these two fuels may be fired. This paper provides the results of NO{sub x} emission stack testing conducted June 15--21, 1999, on the Y-12 Steam Plant Boilers 1 and 2. Measurements of oxygen (O{sub 2}), carbon monoxide (CO), carbon dioxide (CO{sub 2}), and stack gas flow were also performed. Information gained from these stack tests will be used to determine NO{sub x} emission control strategies for the steam plant for compliance with future emission requirements resulting from the NO{sub x} SIP Call.

  12. Greenhouse gas emissions from Australian open-cut coal mines: contribution from spontaneous combustion and low-temperature oxidation.

    PubMed

    Day, Stuart J; Carras, John N; Fry, Robyn; Williams, David J

    2010-07-01

    Spontaneous combustion and low-temperature oxidation of waste coal and other carbonaceous material at open-cut coal mines are potentially significant sources of greenhouse gas emissions. However, the magnitude of these emissions is largely unknown. In this study, emissions from spontaneous combustion and low-temperature oxidation were estimated for six Australian open-cut coal mines with annual coal production ranging from 1.7 to more than 16 Mt. Greenhouse emissions from all other sources at these mines were also estimated and compared to those from spontaneous combustion and low-temperature oxidation. In all cases, fugitive emission of methane was the largest source of greenhouse gas; however, in some mines, spontaneous combustion accounted for almost a third of all emissions. For one mine, it was estimated that emissions from spontaneous combustion were around 250,000 t CO(2)-e per annum. The contribution from low-temperature oxidation was generally less than about 1% of the total for all six mines. Estimating areas of spoil affected by spontaneous combustion by ground-based surveys was prone to under-report the area. Airborne infrared imaging appears to be a more reliable method. PMID:19572109

  13. Intense nitrogen cycling in permeable intertidal sediment revealed by a nitrous oxide hot spot

    NASA Astrophysics Data System (ADS)

    Schutte, Charles A.; Joye, Samantha B.; Wilson, Alicia M.; Evans, Tyler; Moore, Willard S.; Casciotti, Karen

    2015-10-01

    Approximately 40% of the total global rate of nitrogen fixation is the result of human activities, and most of this anthropogenic nitrogen is used to fertilize agricultural fields. Approximately 23% of the applied agricultural nitrogen is delivered to the coastal zone, often reducing water quality and driving eutrophication. Nitrogen cycling in coastal sediments can mitigate eutrophication by removing bioavailable nitrogen. However, some of these processes generate nitrous oxide, a potent greenhouse gas, as a by-product. Here we report the discovery of a nitrous oxide production hot spot in shallow barrier island sands. Nitrous oxide concentrations, production and consumption rates, vertical diffusion fluxes, and flux to the atmosphere were measured across triplicate depth profiles. Using a mass balance approach, rates of net nitrous oxide production were estimated to be 40 µmol m-2 d-1. This production was driven by a hot spot of nitrate consumption that removed bioavailable nitrogen from the coastal environment at a rate of 10 mmol m-2 d-1, a rate that is comparable with the highest rates of denitrification reported for coastal sediments.

  14. Conductivity study of nitrogen-doped calcium zinc oxide prepared by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Hsu, Yu-Ting; Lan, Wen-How; Huang, Kai-Feng; Lin, Jia-Ching; Chang, Kuo-Jen

    2016-01-01

    In this study, the spray pyrolysis method was used to prepare unintentionally doped and nitrogen-doped calcium zinc oxide films by using zinc acetate, calcium nitrate precursor, and ammonium acetate precursor. Morphological and structural analyses were conducted using scanning electron microscopy and X-ray diffraction. The results indicated that film grain size decreased as the nitrogen doping was increased. Both calcium oxide and zinc oxide structures were identified in the unintentionally doped calcium zinc oxide. When nitrogen doping was introduced, the film mainly exhibited a zinc oxide structure with preferred (002) and (101) orientations. The concentration and mobility were investigated using a Hall measurement system. P-type films with a mobility and concentration of 10.6 cm2 V-1 s-1 and 2.8×1017 cm-3, respectively, were obtained. Moreover, according to a temperature-dependent conductivity analysis, an acceptor state with activation energy 0.266 eV dominated the p-type conduction for the unintentionally doped calcium zinc oxide. By contrast, a grain boundary with a barrier height of 0.274-0.292 eV dominated the hole conduction for the nitrogen-doped calcium zinc oxide films.

  15. Oxidation of LDL by myeloperoxidase and reactive nitrogen species: reaction pathways and antioxidant protection.

    PubMed

    Carr, A C; McCall, M R; Frei, B

    2000-07-01

    Oxidative modification of low density lipoprotein (LDL) appears to play an important role in atherogenesis. Although the precise mechanisms of LDL oxidation in vivo are unknown, several lines of evidence implicate myeloperoxidase and reactive nitrogen species, in addition to ceruloplasmin and 15-lipoxygenase. Myeloperoxidase generates a number of reactive species, including hypochlorous acid, chloramines, tyrosyl radicals, and nitrogen dioxide. These reactive species oxidize the protein, lipid, and antioxidant components of LDL. Modification of apolipoprotein B results in enhanced uptake of LDL by macrophages with subsequent formation of lipid-laden foam cells. Nitric oxide synthases produce nitric oxide and, under certain conditions, superoxide radicals. Numerous other sources of superoxide radicals have been identified in the arterial wall, including NAD(P)H oxidases and xanthine oxidase. Nitric oxide and superoxide readily combine to form peroxynitrite, a reactive nitrogen species capable of modifying LDL. In this review, we examine the reaction pathways involved in LDL oxidation by myeloperoxidase and reactive nitrogen species and the potential protective effects of the antioxidant vitamins C and E. PMID:10894808

  16. Nitrogen passivation of deposited oxides on n 4H-SiC

    NASA Astrophysics Data System (ADS)

    Chung, G. Y.; Williams, J. R.; Isaacs-Smith, T.; Ren, F.; McDonald, K.; Feldman, L. C.

    2002-11-01

    Results for measurements of interface state density and breakdown field strength are reported for deposited oxides on n 4H-SiC following passivation with nitric oxide. Low-temperature oxides deposited by plasma-enhanced chemical vapor deposition and high-temperature oxides deposited at 950 °C were investigated. Nitrogen passivation of deposited oxides on n 4H-SiC is found to produce interface state densities of 1-2×1012cm-2 eV-1 at Ec-E=0.1 eV, regardless of variations in oxide deposition procedures that affect the residual interfacial carbon concentration. Breakdown field strengths were higher for passivated high-temperature oxides compared to passivated low-temperature oxides at room temperature and 290 °C. We suggest that additional oxide growth during the NO passivation is the reason for the observed interface state densities.

  17. Ab Initio Studies of Chlorine Oxide and Nitrogen Oxide Species of Interest in Stratospheric Chemistry

    NASA Technical Reports Server (NTRS)

    Lee, Timothy J.; Langhoff, Stephen R. (Technical Monitor)

    1995-01-01

    The ability of modern state-of-the art ab initio quantum chemical techniques to characterize reliably the gas-phase molecular structure, vibrational spectrum, electronic spectrum, and thermal stability of chlorine oxide and nitrogen oxide species will be demonstrated by presentation of some example studies. In particular the geometrical structures, vibrational spectra, and heats of formation Of ClNO2, CisClONO, and trans-ClONO are shown to be in excellent agreement with the available experimental data, and where the experimental data are either not known or are inconclusive, the ab initio results are shown to fill in the gaps and to resolve the experimental controversy. In addition, ab initio studies in which the electronic spectra and the characterization of excited electronic states of ClONO2, HONO2, ClOOC17 ClOOH, and HOOH will also be presented. Again where available, the ab initio results are compared to experimental observations, and are used to aid in the interpretation of the experimental studies.

  18. Apparatus for photocatalytic destruction of internal combustion engine emissions during cold start

    DOEpatents

    Janata, J.; McVay, G.L.; Peden, C.H.; Exarhos, G.J.

    1998-07-14

    A method and apparatus are disclosed for the destruction of emissions from an internal combustion engine wherein a substrate coated with TiO{sub 2} is exposed to a light source in the exhaust system of an internal combustion engine thereby catalyzing oxidation/reduction reactions between gaseous hydrocarbons, carbon monoxide, nitrogen oxides and oxygen in the exhaust of the internal combustion engine. 4 figs.

  19. Evaluation of reaction mechanism of coal-metal oxide interactions in chemical-looping combustion

    SciTech Connect

    Siriwardane, Ranjani; Richards, George; Poston, James; Tian, Hanjing; Miller, Duane; Simonyi, Thomas

    2010-11-15

    The knowledge of reaction mechanism is very important in designing reactors for chemical-looping combustion (CLC) of coal. Recent CLC studies have considered the more technically difficult problem of reactions between abundant solid fuels (i.e. coal and waste streams) and solid metal oxides. A definitive reaction mechanism has not been reported for CLC reaction of solid fuels. It has often been assumed that the solid/solid reaction is slow and therefore requires that reactions be conducted at temperatures high enough to gasify the solid fuel, or decompose the metal oxide. In contrast, data presented in this paper demonstrates that solid/solid reactions can be completed at much lower temperatures, with rates that are technically useful as long as adequate fuel/metal oxide contact is achieved. Density functional theory (DFT) simulations as well as experimental techniques such as thermo-gravimetric analysis (TGA), flow reactor studies, in situ X-ray photo electron spectroscopy (XPS), in situ X-ray diffraction (XRD) and scanning electron microscopy (SEM) are used to evaluate how the proximal interaction between solid phases proceeds. The data indicate that carbon induces the Cu-O bond breaking process to initiate the combustion of carbon at temperatures significantly lower than the spontaneous decomposition temperature of CuO, and the type of reducing medium in the vicinity of the metal oxide influences the temperature at which the oxygen release from the metal oxide takes place. Surface melting of Cu and wetting of carbon may contribute to the solid-solid contacts necessary for the reaction. (author)

  20. Effects of nitrogen flow rate on the properties of indium oxide thin films.

    PubMed

    Cho, Shinho; Kim, Moonhwan

    2013-11-01

    Indium oxide thin films are deposited on glass substrates at nitrogen flow rates of 0-50% by rf reactive magnetron sputtering and are characterized for their structural, morphological, electrical, and optical properties. The experimental results showed that the control of nitrogen flow rate has a significant effect on the properties of the In2O3 thin films. The change in the preferred growth orientation from (222) to (400) planes is observed above a nitrogen flow rate of 10%. The average optical transmittance in the wavelength range of 400-1100 nm is increased from 85.4% at 0% to 86.7% at 50%, where the smallest value of the optical band gap energy is obtained. In addition to the improvement in crystallinity of the films, the nitrogen flow rate plays a crucial role in the fabrication of high-quality indium oxide films and devices. PMID:24245335

  1. Application of a Chemiluminescence Detector for the Measurement of Total Oxides of Nitrogen and Ammonia in the Atmosphere

    NASA Technical Reports Server (NTRS)

    Hodgeson, J. A.; Bell, J. P.; Rehme, K. A.; Krost, K. J.; Stevens, R. K.

    1971-01-01

    By means of the thermal conversion of nitrogen dioxide to the nitric oxide, the chemiluminescent nitric oxide monitor, based on the nitric oxide plus ozone reaction, may be used for monitoring nitrogen dioxide plus nitric oxide (NO(x)). Under conditions previously described, ammonia is also converted to nitric oxide and therefore interferes. A metal surface, gold wool or stainless steel, operated at two different temperatures has been used to convert only nitrogen dioxide or nitrogen dioxide plus ammonia. Quantitative conversion of nitrogen dioxide to nitric oxide has been obtained at temperatures as low as 200 C. Conversion of ammonia is effected at temperatures of 300 C or higher. By the addition of a converter the basic nitric oxide monitor may be used for measuring NO(x) or NO(x) plus ammonia. As an alternate mode, for a fixed high temperature, a specific scrubber is described for removing NH3 without affecting NO2 concentrations.

  2. Toward the Oxidation of the Phenyl Radical and Prevention of PAH Formation in Combustion Systems.

    PubMed

    Parker, Dorian S N; Kaiser, Ralf I; Troy, Tyler P; Kostko, Oleg; Ahmed, Musahid; Mebel, Alexander M

    2015-07-16

    The reaction of the phenyl radical (C6H5) with molecular oxygen (O2) plays a central role in the degradation of poly- and monocyclic aromatic radicals in combustion systems which would otherwise react with fuel components to form polycyclic aromatic hydrocarbons (PAHs) and eventually soot. Despite intense theoretical and experimental scrutiny over half a century, the overall reaction channels have not all been experimentally identified. Tunable vacuum ultraviolet photoionization in conjunction with a combustion simulating chemical reactor uniquely provides the complete isomer specific product spectrum and branching ratios of this prototype reaction. In the reaction of phenyl radicals and molecular oxygen at 873 K and 1003 K, ortho-benzoquinone (o-C6H4O2), the phenoxy radical (C6H5O), and cyclopentadienyl radical (C5H5) were identified as primary products formed through emission of atomic hydrogen, atomic oxygen and carbon dioxide. Furan (C4H4O), acrolein (C3H4O), and ketene (C2H2O) were also identified as primary products formed through ring opening and fragmentation of the 7-membered ring 2-oxepinoxy radical. Secondary reaction products para-benzoquinone (p-C6H4O2), phenol (C6H5OH), cyclopentadiene (C5H6), 2,4-cyclopentadienone (C5H4O), vinylacetylene (C4H4), and acetylene (C2H2) were also identified. The pyranyl radical (C5H5O) was not detected; however, electronic structure calculations show that it is formed and isomerizes to 2,4-cyclopentadienone through atomic hydrogen emission. In combustion systems, barrierless phenyl-type radical oxidation reactions could even degrade more complex aromatic radicals. An understanding of these elementary processes is expected to lead to a better understanding toward the elimination of carcinogenic, mutagenic, and environmentally hazardous byproducts of combustion systems such as PAHs. PMID:25354358

  3. Sandia Combustion Research Program: Annual report, 1986

    SciTech Connect

    Not Available

    1986-01-01

    This report presents research results of the past year, divided thematically into some ten categories. Publications and presentations arising from this work are included in the appendix. Our highlighted accomplishment of the year is the announcement of the discovery and demonstration of the RAPRENOx process. This new mechanism for the elimination of nitrogen oxides from essentially all kinds of combustion exhausts shows promise for commercialization, and may eventually make a significant contribution to our nation's ability to control smog and acid rain. The sections of this volume describe the facility's laser and computer system, laser diagnostics of flames, combustion chemistry, reacting flows, liquid and solid propellant combustion, mathematical models of combustion, high-temperature material interfaces, studies of engine/furnace combustion, coal combustion, and the means of encouraging technology transfer. 182 refs., 170 figs., 12 tabs.

  4. Oxides of nitrogen: Their formation and control in stationary sources. Master's thesis

    SciTech Connect

    Pedrozo, S.P.

    1994-04-24

    Over the last fifty years, a major concern of environmentalists, health care providers, national governments, and international organizations has been the unhealthy and destructive effects of air pollution. In this regard, much attention has the unhealthy and destructive effects of air pollution. In this regard, much attention has been given to a primary pollutant of air - oxides of nitrogen (NO(x)). The two most important oxides of nitrogen with respect to pollution are nitric oxide (NO) and nitrogen dioxide (NO2). In the atmosphere, elevated concentrations of these gases contribute to the greenhouse effect and ozone depletion. In addition, they foster the formation of acid rain and photochemical smog. Lastly, not only do NO(x) contribute directly to these atmospheric reactions, but they also participate in the production of secondary pollutants which have similar effects.

  5. Problems in Catalytic Oxidation of Hydrocarbons and Detailed Simulation of Combustion Processes

    NASA Astrophysics Data System (ADS)

    Xin, Yuxuan

    This dissertation research consists of two parts, with Part I on the kinetics of catalytic oxidation of hydrocarbons and Part II on aspects on the detailed simulation of combustion processes. In Part I, the catalytic oxidation of C1--C3 hydrocarbons, namely methane, ethane, propane and ethylene, was investigated for lean hydrocarbon-air mixtures over an unsupported Pd-based catalyst, from 600 to 800 K and under atmospheric pressure. In Chapter 2, the experimental facility of wire microcalorimetry and simulation configuration were described in details. In Chapter 3 and 4, the oxidation rate of C1--C 3 hydrocarbons is demonstrated to be determined by the dissociative adsorption of hydrocarbons. A detailed surface kinetics model is proposed with deriving the rate coefficient of hydrocarbon dissociative adsorption from the wire microcalorimetry data. In Part II, four fundamental studies were conducted through detailed combustion simulations. In Chapter 5, self-accelerating hydrogen-air flames are studied via two-dimensional detailed numerical simulation (DNS). The increase in the global flame velocity is shown to be caused by the increase of flame surface area, and the fractal structure of the flame front is demonstrated by the box-counting method. In Chapter 6, skeletal reaction models for butane combustion are derived by using directed relation graph (DRG) and DRG-aided sensitivity analysis (DRGASA), and uncertainty minimization by polynomial chaos expansion (MUM-PCE) mothodes. The dependence of model uncertainty is subjected to the completeness of the model. In Chapter 7, a systematic strategy is proposed to reduce the cost of the multicomponent diffusion model by accurately accounting for the species whose diffusivity is important to the global responses of the combustion systems, and approximating those of less importance by the mixture-averaged model. The reduced model is validated in an n-heptane mechanism with 88 species. In Chapter 8, the influence of Soret

  6. Synthesis of α-Bismuth oxide using solution combustion method and its photocatalytic properties

    NASA Astrophysics Data System (ADS)

    Astuti, Y.; Fauziyah, A.; Nurhayati, S.; Wulansari, A. D.; Andianingrum, R.; Hakim, A. R.; Bhaduri, G.

    2016-02-01

    The monoclinic bismuth oxide was prepared by the solution combustion method using bismuthyl nitrate as the raw material and citric acid as fuel. The synthesis process consisted of the formation of a clear transparent solution and the formation of white powder after heating the mixture at 250 °C for 2 hours. The yellow pale crystalline materials were obtained after calcination of the white powder at 600 °C for 80 minutes. Furthermore, the photocatalytic activity of the product was also studied using methyl orange as a model pollutant. The result showed that the coral reef-like bismuth oxide was able to degrade 50 mL methyl orange (5 ppm) by 37.8% within 12 hours irradiation using 75-watt tungsten lamp.

  7. A unified intermediate and mechanism for soot combustion on potassium-supported oxides

    PubMed Central

    Li, Qian; Wang, Xiao; Xin, Ying; Zhang, Zhaoliang; Zhang, Yexin; Hao, Ce; Meng, Ming; Zheng, Lirong; Zheng, Lei

    2014-01-01

    The soot combustion mechanism over potassium-supported oxides (MgO, CeO2 and ZrO2) was studied to clarify the active sites and discover unified reaction intermediates in this typical gas-solid-solid catalytic reaction. The catalytically active sites were identified as free K+ rather than K2CO3, which can activate gaseous oxygen. The active oxygen spills over to soot and forms a common intermediate, ketene, before it was further oxidized into the end product CO2. The existence of ketene species was confirmed by density functional theory (DFT) calculations. The oxygen spillover mechanism is proposed, which is explained as an electron transfer from soot to gaseous oxygen through the active K+ sites. The latter mechanism is confirmed for the first time since it was put forward in 1950, not only by ultraviolet photoelectron spectroscopy (UPS) results but also by semi-empirical theoretical calculations. PMID:24740213

  8. Anaerobic ammonium oxidation and its contribution to nitrogen removal in China’s coastal wetlands

    PubMed Central

    Hou, Lijun; Zheng, Yanling; Liu, Min; Li, Xiaofei; Lin, Xianbiao; Yin, Guoyu; Gao, Juan; Deng, Fengyu; Chen, Fei; Jiang, Xiaofen

    2015-01-01

    Over the past several decades, human activities have caused substantial enrichment of reactive nitrogen in China’s coastal wetlands. Although anaerobic ammonium oxidation (anammox), the process of oxidizing ammonium into dinitrogen gas through the reduction of nitrite, is identified as an important process for removing reactive nitrogen, little is known about the dynamics of anammox and its contribution to nitrogen removal in nitrogen-enriched environments. Here, we examine potential rates of anammox and associate them with bacterial diversity and abundance across the coastal wetlands of China using molecular and isotope tracing techniques. High anammox bacterial diversity was detected in China’s coastal wetlands and included Candidatus Scalindua, Kuenenia, Brocadia, and Jettenia. Potential anammox rates were more closely associated with the abundance of anammox bacteria than to their diversity. Among all measured environmental variables, temperature was a key environmental factor, causing a latitudinal distribution of the anammox bacterial community composition, biodiversity and activity along the coastal wetlands of China. Based on nitrogen isotope tracing experiments, anammox was estimated to account for approximately 3.8–10.7% of the total reactive nitrogen removal in the study area. Combined with denitrification, anammox can remove 20.7% of the total external terrigenous inorganic nitrogen annually transported into China’s coastal wetland ecosystems. PMID:26494435

  9. Anaerobic ammonium oxidation and its contribution to nitrogen removal in China’s coastal wetlands

    NASA Astrophysics Data System (ADS)

    Hou, Lijun; Zheng, Yanling; Liu, Min; Li, Xiaofei; Lin, Xianbiao; Yin, Guoyu; Gao, Juan; Deng, Fengyu; Chen, Fei; Jiang, Xiaofen

    2015-10-01

    Over the past several decades, human activities have caused substantial enrichment of reactive nitrogen in China’s coastal wetlands. Although anaerobic ammonium oxidation (anammox), the process of oxidizing ammonium into dinitrogen gas through the reduction of nitrite, is identified as an important process for removing reactive nitrogen, little is known about the dynamics of anammox and its contribution to nitrogen removal in nitrogen-enriched environments. Here, we examine potential rates of anammox and associate them with bacterial diversity and abundance across the coastal wetlands of China using molecular and isotope tracing techniques. High anammox bacterial diversity was detected in China’s coastal wetlands and included Candidatus Scalindua, Kuenenia, Brocadia, and Jettenia. Potential anammox rates were more closely associated with the abundance of anammox bacteria than to their diversity. Among all measured environmental variables, temperature was a key environmental factor, causing a latitudinal distribution of the anammox bacterial community composition, biodiversity and activity along the coastal wetlands of China. Based on nitrogen isotope tracing experiments, anammox was estimated to account for approximately 3.8-10.7% of the total reactive nitrogen removal in the study area. Combined with denitrification, anammox can remove 20.7% of the total external terrigenous inorganic nitrogen annually transported into China’s coastal wetland ecosystems.

  10. Reactive nitrogen oxides in the southeast United States national parks: source identification, origin, and process budget

    NASA Astrophysics Data System (ADS)

    Tong, Daniel Quansong; Kang, Daiwen; Aneja, Viney P.; Ray, John D.

    2005-01-01

    We present in this study both measurement-based and modeling analyses for elucidation of source attribution, influence areas, and process budget of reactive nitrogen oxides at two rural southeast United States sites (Great Smoky Mountains national park (GRSM) and Mammoth Cave national park (MACA)). Availability of nitrogen oxides is considered as the limiting factor to ozone production in these areas and the relative source contribution of reactive nitrogen oxides from point or mobile sources is important in understanding why these areas have high ozone. Using two independent observation-based techniques, multiple linear regression analysis and emission inventory analysis, we demonstrate that point sources contribute a minimum of 23% of total NOy at GRSM and 27% at MACA. The influence areas for these two sites, or origins of nitrogen oxides, are investigated using trajectory-cluster analysis. The result shows that air masses from the West and Southwest sweep over GRSM most frequently, while pollutants transported from the eastern half (i.e., East, Northeast, and Southeast) have limited influence (<10% out of all air masses) on air quality at GRSM. The processes responsible for formation and removal of reactive nitrogen oxides are investigated using a comprehensive 3-D air quality model (Multiscale Air Quality SImulation Platform (MAQSIP)). The NOy contribution associated with chemical transformations to NOz and O3, based on process budget analysis, is as follows: 32% and 84% for NOz, and 26% and 80% for O3 at GRSM and MACA, respectively. The similarity between NOz and O3 process budgets suggests a close association between nitrogen oxides and effective O3 production at these rural locations.

  11. Spray-combustion synthesis: efficient solution route to high-performance oxide transistors.

    PubMed

    Yu, Xinge; Smith, Jeremy; Zhou, Nanjia; Zeng, Li; Guo, Peijun; Xia, Yu; Alvarez, Ana; Aghion, Stefano; Lin, Hui; Yu, Junsheng; Chang, Robert P H; Bedzyk, Michael J; Ferragut, Rafael; Marks, Tobin J; Facchetti, Antonio

    2015-03-17

    Metal-oxide (MO) semiconductors have emerged as enabling materials for next generation thin-film electronics owing to their high carrier mobilities, even in the amorphous state, large-area uniformity, low cost, and optical transparency, which are applicable to flat-panel displays, flexible circuitry, and photovoltaic cells. Impressive progress in solution-processed MO electronics has been achieved using methodologies such as sol gel, deep-UV irradiation, preformed nanostructures, and combustion synthesis. Nevertheless, because of incomplete lattice condensation and film densification, high-quality solution-processed MO films having technologically relevant thicknesses achievable in a single step have yet to be shown. Here, we report a low-temperature, thickness-controlled coating process to create high-performance, solution-processed MO electronics: spray-combustion synthesis (SCS). We also report for the first time, to our knowledge, indium-gallium-zinc-oxide (IGZO) transistors having densification, nanoporosity, electron mobility, trap densities, bias stability, and film transport approaching those of sputtered films and compatible with conventional fabrication (FAB) operations. PMID:25733848

  12. Spray-combustion synthesis: Efficient solution route to high-performance oxide transistors

    PubMed Central

    Yu, Xinge; Smith, Jeremy; Zhou, Nanjia; Zeng, Li; Guo, Peijun; Xia, Yu; Alvarez, Ana; Aghion, Stefano; Lin, Hui; Yu, Junsheng; Chang, Robert P. H.; Bedzyk, Michael J.; Ferragut, Rafael; Marks, Tobin J.; Facchetti, Antonio

    2015-01-01

    Metal-oxide (MO) semiconductors have emerged as enabling materials for next generation thin-film electronics owing to their high carrier mobilities, even in the amorphous state, large-area uniformity, low cost, and optical transparency, which are applicable to flat-panel displays, flexible circuitry, and photovoltaic cells. Impressive progress in solution-processed MO electronics has been achieved using methodologies such as sol gel, deep-UV irradiation, preformed nanostructures, and combustion synthesis. Nevertheless, because of incomplete lattice condensation and film densification, high-quality solution-processed MO films having technologically relevant thicknesses achievable in a single step have yet to be shown. Here, we report a low-temperature, thickness-controlled coating process to create high-performance, solution-processed MO electronics: spray-combustion synthesis (SCS). We also report for the first time, to our knowledge, indium-gallium-zinc-oxide (IGZO) transistors having densification, nanoporosity, electron mobility, trap densities, bias stability, and film transport approaching those of sputtered films and compatible with conventional fabrication (FAB) operations. PMID:25733848

  13. Surface combustion microengines based on photocatalytic oxidations of hydrocarbons at room temperature.

    PubMed

    Su, Ming; Dravid, Vinayak P

    2005-10-01

    The concept of a surface combustion microengine that is fuelled by volatile hydrocarbons at room temperature is demonstrated on a microcantilever covered with a thin layer of titanium oxide (TiO(2)). Exposing this microengine to ultraviolet (UV) radiation and hydrocarbon vapor produces controlled bending of the microcantilever as a result of differential stress produced by photocatalytic oxidation of organic molecules on the TiO(2) coating. Compared to the motion generated solely by UV radiation or hydrocarbon adsorption, the unique photocatalytic-mechanical effects in the presence of UV and hydrocarbon produce more work and exhibit fast response. The surface combustion based microengines would require less maintenance in minimally controlled field environment and could be potentially used in construction of miniature movable machines, conversion of solar and chemical energy to mechanical work, when extended to a large array of microcantilevers. We believe such microengines can be fuelled by a variety of molecules or mixtures due to the generally favorable photocatalytic reactivity of TiO(2), thus potentially offering a broad approach for mechanical work generation from multiple energy sources. PMID:16218731

  14. One - Step synthesis of nitrogen doped reduced graphene oxide with NiCo nanoparticles for ethanol oxidation in alkaline media.

    PubMed

    Kakaei, Karim; Marzang, Kamaran

    2016-01-15

    Development of anode catalysts and catalyst supporting carbonaceous material containing non-precious metal have attracted tremendous attention in the field of direct ethanol fuel cells (DEFCs). Herein, we report the synthesis and electrochemical properties of nitrogen-doped reduced graphene oxide (NRGO) supported Co, Ni and NiCo nanocomposites. The metal NRGO nanocomposites, in which metal nanoparticles are embedded in the highly porous nitrogen-doped graphene matrix, have been synthesized by simply and one-pot method at a mild temperature using GO, urea choline chloride and urea as reducing and doping agent. The fabricated NiCo/NRGO exhibit remarkable electrocatalytic activity (with Tafel slope of 159.1mVdec(-1)) and high stability for the ethanol oxidation reaction (EOR). The superior performance of the alloy based NRGO is attributed to high surface area, well uniform distribution of high-density nitrogen, metal active sites and synergistic effect. PMID:26454373

  15. 75 FR 70258 - Review of the Secondary National Ambient Air Quality Standards for Oxides of Nitrogen and Oxides...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-17

    ... Nitrogen and Oxides of Sulfur: Second External Review Draft (75 FR 57463, September 21, 2010). The EPA... a later date (75 FR 61486, October 5, 2010). The supplementary materials were: an errata sheet for... an atmospheric chemistry perspective as well as from an environmental effects perspective,...

  16. Reduction in nitrogen oxides emission on TGME-464 boiler of IRU power plant (Estonia)

    NASA Astrophysics Data System (ADS)

    Roslyakov, P. V.; Ionkin, I. L.

    2015-01-01

    The possibility for realization of measures on a reduction in nitrogen oxides emission on a TGME-464 (plant no. 2) boiler of the IRU power plant (Tallinn, Estonia) is investigated. Low-cost techno-logical measures, namely, nonstoichiometric burning and burning with the moderate controlled chemical underburning, are proposed and experimentally tested. Recommendations on the implementation of low-emission modes of burning natural gas into mode diagrams of the boiler are given. Nitrogen oxides emissions are reduced to the required level as a result of the implementation of the proposed measures.

  17. Energy, industry and nitrogen: strategies for decreasing reactive nitrogen emissions.

    PubMed

    Moomaw, William R

    2002-03-01

    Nitrogen oxides are released during atmospheric combustion of fossil fuels and biomass, and during the production of certain chemicals and products. They can react with natural or man-made volatile organic compounds to produce smog, or else can be further oxidized to produce particulate haze, or acid rain that can eutrophy land and water. The reactive nitrogen that begins in the energy sector thus cascades through the atmosphere, the hydrosphere and soils before being eventually partially denitrifed to the global warming and stratospheric ozone-depleting gas nitrous oxide or molecular nitrogen. This paper will suggest how an economic analysis of the nitrogen cycle can identify the most cost-effective places to intervene. Nitrogen oxides released during fossil-fuel combustion in vehicles, power plants and heating boilers can either be controlled by add-on emission control technology, or can be eliminated by many of the same technical options that lead to carbon dioxide reduction. These integrated strategies also address sustainability, economic development and national security issues. Similarly in industrial production, it is more effective to focus on redesigning industrial processes rather than on nitrogen oxide pollution elimination from the current system. This paper will suggest which strategies might be utilized to address multiple benefits rather than focusing on single pollutants. PMID:12078008

  18. Fluidized-bed combustion reduces atmospheric pollutants

    NASA Technical Reports Server (NTRS)

    Jonke, A. A.

    1972-01-01

    Method of reducing sulfur and nitrogen oxides released during combustion of fossil fuels is described. Fuel is burned in fluidized bed of solids with simultaneous feeding of crushed or pulverized limestone to control emission. Process also offers high heat transfer rates and efficient contacting for gas-solid reactions.

  19. Diet-induced atherosclerosis increases the release of nitrogen oxides from rabbit aorta.

    PubMed Central

    Minor, R L; Myers, P R; Guerra, R; Bates, J N; Harrison, D G

    1990-01-01

    We examined the hypothesis that impaired endothelium-dependent vasodilation in atherosclerosis is associated with decreased synthesis of nitrogen oxides by the vascular endothelium. The descending thoracic aortae of rabbits fed either normal diet, a high cholesterol diet for 2-5 wk (hypercholesterolemic, HC), or a high cholesterol diet for 6 mo (atherosclerotic, AS) were perfused in a bioassay organ chamber with physiologic buffer containing indomethacin. Despite a dramatic impairment in the vasodilator activity of endothelium-dependent relaxing factor (EDRF) released from both HC and AS aortae (assessed by bioassay), the release of nitrogen oxides (measured by chemiluminescence) from these vessels was not reduced, but markedly increased compared to NL. Thus, impaired endothelium-dependent relaxation in atherosclerosis is neither due to decreased activity of the enzyme responsible for the production of nitrogen oxides from arginine nor to arginine deficiency. Because the production of nitrogen oxides increased in response to acetylcholine in both hypercholesterolemic and atherosclerotic vessels, impairments in signal transduction are not responsible for abnormal endothelium-dependent relaxations. Impaired vasodilator activity of EDRF by cholesterol feeding may result from loss of incorporation of nitric oxide into a more potent parent compound, or accelerated degradation of EDRF. Images PMID:2254462

  20. Reductions in nitrogen oxides over Europe driven by environmental policy and economic recession

    PubMed Central

    Castellanos, Patricia; Boersma, K. Folkert

    2012-01-01

    Fuel combustion is a significant source of numerous air pollutants, which reduce local air quality, and affect global tropospheric chemistry. Satellite observations of nitrogen dioxide, emitted by combustion processes, allow for robust monitoring of atmospheric concentrations at high spatial resolution on continental scales. Here we evaluate changes in tropospheric NO2 concentrations over Europe between 2004 and 2010. We isolate long-term (timescales greater than one year) variability in the daily NO2 observations from the Ozone Monitoring Instrument (OMI) using a spectral analysis. In 2010, we find substantial reductions in NO2 concentrations of at least 20% throughout Europe. These reductions are as much the result of temporary reductions prompted by the 2008–2009 global economic recession, as of European NOx emission controls. Our results demonstrate that realistic concentration pathways of NO2 do not follow simple linear trends, but reflect a compilation of environmental policy and economic activity. PMID:22355777