WorldWideScience

Sample records for understanding nox emissions

  1. Understanding NOx emission trends in China based on OMI observations

    Science.gov (United States)

    Wang, Y.; Ga, D.; Smeltzer, C. D.; Yi, R.; Liu, Z.

    2012-12-01

    We analyze OMI observations of NO2 columns over China from 2005 to 2010. Simulations using a regional 3-D chemical transport model (REAM) are used to derive the top-down anthropogenic NOx emissions. The Kendall method is then applied to derive the emission trend. The emission trend is affected by the economic slowdown in 2009. After removing the effect of one year abnormal data, the overall emission trend is 4.35±1.42% per year, which is slower than the linear-regression trend of 5.8-10.8% per year reported for previous years. We find large regional, seasonal, and urban-rural variations in emission trend. The annual emission trends of Northeast China, Central China Plain, Yangtze River Delta and Pearl River Delta are 44.98±1.39%, 5.24±1.63%, 3.31±1.02% and -4.02±1.87%, respectively. The annual emission trends of four megacities, Beijing, Shanghai, Guangzhou and Shenzhen are 0.7±0.27%, -0.75±0.31%, -4.08±1.21% and -6.22±2.85%,, considerably lower than the regional averages. These results appear to suggest that a number of factors, including migration of high-emission industries, vehicle emission regulations, emission control measures of thermal power plants, increased hydro-power usage, have reduced or reversed the increasing trend of NOx emissions in more economically developed megacities and southern coastal regions.

  2. Correlating Engine NOx Emission with Biodiesel Composition

    Science.gov (United States)

    Jeyaseelan, Thangaraja; Mehta, Pramod Shankar

    2017-06-01

    Biodiesel composition comprising of saturated and unsaturated fatty acid methyl esters has a significant influence on its properties and hence the engine performance and emission characteristics. This paper proposes a comprehensive approach for composition-property-NOx emission analysis for biodiesel fuels and highlights the pathways responsible for such a relationship. Finally, a procedure and a predictor equation are developed for the assessment of biodiesel NOx emission from its composition details.

  3. Understanding NOx SCR Mechanism and Activity on Cu/Chabazite Structures throughout the Catalyst Life Cycle

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Fabio; Delgass, Nick; Gounder, Rajmani; Schneider, William F.; Miller, Jeff; Yezerets, Aleksey; McEwen, Jean-Sabin; Peden, Charles HF; Howden, Ken

    2014-12-09

    Oxides of nitrogen (NOx) compounds contribute to acid rain and photochemical smog and have been linked to respiratory ailments. NOx emissions regulations continue to tighten, driving the need for high performance, robust control strategies. The goal of this project is to develop a deep, molecular level understanding of the function of Cu-SSZ-13 and Cu-SAPO-34 materials that catalyze the SCR of NOx with NH3.

  4. Evaluation of NOx Emissions and Modeling

    Science.gov (United States)

    Henderson, B. H.; Simon, H. A.; Timin, B.; Dolwick, P. D.; Owen, R. C.; Eyth, A.; Foley, K.; Toro, C.; Baker, K. R.

    2017-12-01

    Studies focusing on ambient measurements of NOy have concluded that NOx emissions are overestimated and some have attributed the error to the onroad mobile sector. We investigate this conclusion to identify the cause of observed bias. First, we compare DISCOVER-AQ Baltimore ambient measurements to fine-scale modeling with NOy tagged by sector. Sector-based relationships with bias are present, but these are sensitive to simulated vertical mixing. This is evident both in sensitivity to mixing parameterization and the seasonal patterns of bias. We also evaluate observation-based indicators, like CO:NOy ratios, that are commonly used to diagnose emissions inventories. Second, we examine the sensitivity of predicted NOx and NOy to temporal allocation of emissions. We investigate alternative temporal allocations for EGUs without CEMS, on-road mobile, and several non-road categories. These results show some location-specific sensitivity and will lead to some improved temporal allocations. Third, near-road studies have inherently fewer confounding variables, and have been examined for more direct evaluation of emissions and dispersion models. From 2008-2011, the EPA and FHWA conducted near-road studies in Las Vegas and Detroit. These measurements are used to more directly evaluate the emissions and dispersion using site-specific traffic data. In addition, the site-specific emissions are being compared to the emissions used in larger-scale photochemical modeling to identify key discrepancies. These efforts are part of a larger coordinated effort by EPA scientist to ensure the highest quality in emissions and model processes. We look forward to sharing the state of these analyses and expected updates.

  5. 40 CFR 60.4320 - What emission limits must I meet for nitrogen oxides (NOX)?

    Science.gov (United States)

    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. ...

  6. Verification of NOx emission inventories over North Korea.

    Science.gov (United States)

    Kim, Na Kyung; Kim, Yong Pyo; Morino, Yu; Kurokawa, Jun-ichi; Ohara, Toshimasa

    2014-12-01

    In this study, the top-down NOx emissions estimated from satellite observations of NO2 vertical column densities over North Korea from 1996 to 2009 were analyzed. Also, a bottom-up NOx emission inventory from REAS 1.1 from 1980 to 2005 was analyzed with several statistics. REAS 1.1 was in good agreement with the top-down approach for both trend and amount. The characteristics of NOx emissions in North Korea were quite different from other developed countries including South Korea. In North Korea, emissions from industry sector was the highest followed by transportation sector in the 1980s. However, after 1990, the NOx emissions from other sector, mainly agriculture, became the 2nd highest. Also, no emission centers such as urban areas or industrial areas were distinctively observed. Finally, the monthly NOx emissions were high during the warm season. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. NOx EMISSIONS PRODUCED WITH COMBUSTION OF POWDER RIVER BASIN COAL IN A UTILITY BOILER

    Energy Technology Data Exchange (ETDEWEB)

    John S. Nordin; Norman W. Merriam

    1997-04-01

    The objective of this report is to estimate the NOx emissions produced when Powder River Basin (PRB) coal is combusted in a utility boiler. The Clean Air Act regulations specify NOx limits of 0.45 lb/mm Btu (Phase I) and 0.40 lb/mm Btu (Phase II) for tangentially fired boilers, and 0.50 lb/mm 13tu (Phase II) and 0.46 lb/mm Btu (Phase II) for dry-bottom wall-fired boilers. The Clean Air Act regulations also specify other limits for other boiler types. Compliance for Phase I has been in effect since January 1, 1996. Compliance for Phase II goes into effect on January 1, 2000. Emission limits are expressed as equivalent NO{sub 2} even though NO (and sometimes N{sub 2}O) is the NOx species emitted during combustion. Regulatory agencies usually set even lower NOx emission limits in ozone nonattainment areas. In preparing this report, Western Research Institute (WRI) used published test results from utilities burning various coals, including PRB coal, using state-of-the art control technology for minimizing NOx emissions. Many utilities can meet Clean Air Act NOx emission limits using a combination of tight combustion control and low-NOx burners and by keeping furnaces clean (i.e., no slag buildup). In meeting these limits, some utilities also report problems such as increased carbon in their fly ash and excessive furnace tube corrosion. This report discusses utility experience. The theory of NOx emission formation during coal combustion as related to coal structure and how the coal is combusted is also discussed. From this understanding, projections are made for NOx emissions when processed PRB coal is combusted in a test similar to that done with other coals. As will be shown, there are a lot of conditions for achieving low NOx emissions, such as tight combustion control and frequent waterlancing of the furnace to avoid buildup of deposits.

  8. Reducing global NOx emissions: developing advanced energy and transportation technologies.

    Science.gov (United States)

    Bradley, Michael J; Jones, Brian M

    2002-03-01

    Globally, energy demand is projected to continue to increase well into the future. As a result, global NOx emissions are projected to continue on an upward trend for the foreseeable future as developing countries increase their standards of living. While the US has experienced improvements in reducing NOx emissions from stationary and mobile sources to reduce ozone, further progress is needed to reduce the health and ecosystem impacts associated with NOx emissions. In other parts of the world, (in developing countries in particular) NOx emissions have been increasing steadily with the growth in demand for electricity and transportation. Advancements in energy and transportation technologies may help avoid this increase in emissions if appropriate policies are implemented. This paper evaluates commercially available power generation and transportation technologies that produce fewer NOx emissions than conventional technologies, and advanced technologies that are on the 10-year commercialization horizon. Various policy approaches will be evaluated which can be implemented on the regional, national and international levels to promote these advanced technologies and ultimately reduce NOx emissions. The concept of the technology leap is offered as a possibility for the developing world to avoid the projected increases in NOx emissions.

  9. DEVELOPMENT OF A NOVEL RADIATIVELY/CONDUCTIVELY STABILIZED BURNER FOR SIGNIFICANT REDUCTION OF NOx EMISSIONS AND FOR ADVANCING THE MODELING AND UNDERSTANDING OF PULVERIZED COAL COMBUSTION AND EMISSIONS

    Energy Technology Data Exchange (ETDEWEB)

    Noam Lior; Stuart W. Churchill

    2003-10-01

    The primary objective of the proposed study was the study and analysis of, and design recommendations for, a novel radiatively-conductively stabilized combustion (RCSC) process for pulverized coal, which, based on our prior studies with both fluid fuels and pulverized coal, holds a high promise to reduce NO{sub x} production significantly. We have primarily engaged in continuing and improving our process modeling and analysis, obtained a large amount of quantitative information about the effects of the major parameters on NO{sub x} production, conducted an extensive exergy analysis of the process, evaluated the practicalities of employing the Radiatively-Conductively Stabilized Combustor (RCSC) to large power and heat plants, and improved the experimental facility. Prior experimental work has proven the feasibility of the combustor, but slagging during coal combustion was observed and should be dealt with. The primary outcomes and conclusions from the study are: (1) we developed a model and computer program that represents the pulverized coal combustion in the RCSC, (2) the model predicts that NO{sub x} emissions can be reduced by a number of methods, detailed in the report. (3) the exergy analysis points out at least a couple of possible ways to improve the exergetic efficiency in this combustor: increasing the effectiveness of thermal feedback, and adjusting the combustor mixture exit location, (4) because of the low coal flow rates necessitated in this study to obtain complete combustion in the burner, the size of a burner operating under the considered conditions would have to be up to an order of magnitude, larger than comparable commercial burners, but different flow configurations of the RCSC can yield higher feed rates and smaller dimensions, and should be investigated. Related to this contract, eleven papers were published in journals and conference proceedings, and ten invited presentations were given at university and research institutions, as well as at

  10. NOx Emissions from Diesel Passenger Cars Worsen with Age.

    Science.gov (United States)

    Chen, Yuche; Borken-Kleefeld, Jens

    2016-04-05

    Commonly, the NOx emissions rates of diesel vehicles have been assumed to remain stable over the vehicle's lifetime. However, there have been hardly any representative long-term emission measurements. Here we present real-driving emissions of diesel cars and light commercial vehicles sampled on-road over 15 years in Zurich/Switzerland. Results suggest deterioration of NOx unit emissions for Euro 2 and Euro 3 diesel technologies, while Euro 1 and Euro 4 technologies seem to be stable. We can exclude a significant influence of high-emitting vehicles. NOx emissions from all cars and light commercial vehicles in European emission inventories increase by 5-10% accounting for the observed deterioration, depending on the country and its share of diesel cars. We suggest monitoring the stability of emission controls particularly for high-mileage light commercial as well as heavy-duty vehicles.

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

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Pu-Xian

    2013-07-31

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

  12. Lightning NOx Emissions: Reconciling Measured and Modeled Estimates With Updated NOx Chemistry

    Science.gov (United States)

    Nault, B. A.; Laughner, J. L.; Wooldridge, P. J.; Crounse, J. D.; Dibb, J.; Diskin, G.; Peischl, J.; Podolske, J. R.; Pollack, I. B.; Ryerson, T. B.; Scheuer, E.; Wennberg, P. O.; Cohen, R. C.

    2017-09-01

    Lightning is one of the most important sources of upper tropospheric NOx; however, there is a large spread in estimates of the global emission rates (2-8 Tg N yr-1). We combine upper tropospheric in situ observations from the Deep Convective Clouds and Chemistry (DC3) experiment and global satellite-retrieved NO2 tropospheric column densities to constrain mean lightning NOx (LNOx) emissions per flash. Insights from DC3 indicate that the NOx lifetime is 3 h in the region of outflow of thunderstorms, mainly due to production of methyl peroxy nitrate and alkyl and multifunctional nitrates. The lifetime then increases farther downwind from the region of outflow. Reinterpreting previous analyses using the 3 h lifetime reduces the spread among various methods that have been used to calculate mean LNOx emissions per flash and indicates a global LNOx emission rate of 9 Tg N yr-1, a flux larger than the high end of recent estimates.

  13. ULTRA LOW NOx INTEGRATED SYSTEM FOR NOx EMISSION CONTROL FROM COAL-FIRED BOILERS

    Energy Technology Data Exchange (ETDEWEB)

    Galen H. Richards; Charles Q. Maney; Richard W. Borio; Robert D. Lewis

    2002-12-30

    ALSTOM Power Inc.'s Power Plant Laboratories, working in concert with ALSTOM Power's Performance Projects Group, has teamed with the U.S. Department of Energy's National Energy Technology Laboratory (DOE NETL) to conduct a comprehensive study to develop/evaluate low-cost, efficient NOx control technologies for retrofit to pulverized coal fired utility boilers. The objective of this project was to develop retrofit NOx control technology to achieve less than 0.15 lb/MMBtu NOx (for bituminous coals) and 0.10 lb/MMBtu NOx (for subbituminous coals) from existing pulverized coal fired utility boilers at a cost which is at least 25% less than SCR technology. Efficient control of NOx is seen as an important, enabling step in keeping coal as a viable part of the national energy mix in this century, and beyond. Presently 57% of U.S. electrical generation is coal based, and the Energy Information Agency projects that coal will maintain a lead in U.S. power generation over all other fuel sources for decades (EIA 1998 Energy Forecast). Yet, coal-based power is being strongly challenged by society's ever-increasing desire for an improved environment and the resultant improvement in health and safety. The needs of the electric-utility industry are to improve environmental performance, while simultaneously improving overall plant economics. This means that emissions control technology is needed with very low capital and operating costs. This project has responded to the industry's need for low NOx emissions by evaluating ideas that can be adapted to present pulverized coal fired systems, be they conventional or low NOx firing systems. The TFS 2000{trademark} firing system has been the ALSTOM Power Inc. commercial offering producing the lowest NOx emission levels. In this project, the TFS 2000{trademark} firing system served as a basis for comparison to other low NOx systems evaluated and was the foundation upon which refinements were made to further

  14. Control strategies for vehicular NOx emissions in Guangzhou, China

    International Nuclear Information System (INIS)

    Shao Min; Zhang Yuanhang; Raufer, Roger

    2001-01-01

    Guangzhou is a city in southern China that has experienced very rapid economic development in recent years. The city's air has very high concentrations of various pollutants, including sulphur dioxide (SO 2 , oxides of nitrogen (NOx), ozone (O 3 ) and particulate. This paper reviews the changes in air quality in the city over the past 15 years, and notes that a serious vehicular-related emissions problem has been superimposed on the traditional coal-burning problem evident in most Chinese cities. As NOx concentrations have increased, oxidants and photochemical smog now interact with the traditional SO 2 and particulate pollutants, leading to increased health risks and other environmental concerns. Any responsible NOx control strategy for the city must include vehicle emission control measures. This paper reviews control strategies designed to abate vehicle emissions to fulfill the city's air quality improvement target in 2010. A cost-effectiveness analysis suggests that, while NOx emission control is expensive, vehicular emission standards could achieve a relatively sizable emissions reduction at reasonable cost. To achieve the 2010 air quality target of NOx, advanced implementation of EURO3 standards is recommended, substituting for the EURO2 currently envisioned in the national regulations Related technical options, including fuel quality improvements and inspection/maintenance (I/M) upgrades (ASM or IM240) are assessed as well. (author)

  15. Minimising NOx emissions: a symptom of managing change

    Energy Technology Data Exchange (ETDEWEB)

    Howard, J. [UltraMax Corporation (USA)

    2000-07-01

    Minimizing NOx emissions is but a symptom of a bigger issues for utility companies in today's world. The bigger issue is determining how to successfully manage change. The companies that manage change well will solve the environmental issues and solve them profitably. NOx reduction can be achieved. It can be achieved while creating a capability to manage change. Solving the ability to manage change is the best route to take. Reducing NOx can be done but it may create other problems such as increased carbon in ash. The combination of software and hardware solutions have been carefully thought through and efficiently implemented. 7 figs., 2 tabs.

  16. Impact of FCC regenerator design in the NOx emissions

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Hugo Borges; Sandes, Emanuel Freire; Gilbert, William Richard; Roncolatto, Rodolfo Eugenio; Gobbo, Rodrigo; Casavechia, Luiz Carlos; Candido, William Victor Carlos [Petroleo Brasileiro S.A. (PETROBRAS), Rio de Janeiro, RJ (Brazil); Bridi, Patricia Elaine [Possebon Engenharia, Sao Mateus do Sul, PR (Brazil)

    2012-07-01

    Fluid Catalytic Cracking (FCC) is the main point source of NOx in the refinery and it is responsible for at least 20% of the total NOx emissions from the refineries. The thermal NOx formation in the FCC regenerator is negligible. However, half of the feed nitrogen is converted to coke, and is burned in the regenerator. The majority of coke nitrogen is reduced to N2 and less than 10% is converted to NOx. This number may vary significantly with the oxygen excess in the flue gas and other operational conditions. With the purpose of evaluating the impact of different regenerator designs in NOx formation, several tests were carried out in the PETROBRAS FCC prototype unit. The test unit is equipped with adiabatic insulation and a CO boiler, allowing it to reproduce the heat balance of a commercial FCC and to operate either in full combustion or partial combustion. Two different designs of FCC regenerators were evaluated: single stage regenerator (the existing configuration) and two stage regenerator, with the catalyst bed divided into two sections by a structured packing baffle. It was observed in the tests that the combustion regime had a very strong effect on NOx formation. In full combustion, the effect of the FCC operating variables: excess oxygen, combustion promoter content in catalyst and regenerator design could be identified. The two stage configuration was capable of decreasing NOx emissions by 30%. In partial combustion, the effect of the CO-boiler variables on NOx emissions was overwhelming, but the use of the structured packing baffle was able to improve the catalyst regeneration.(author)

  17. Real world NOx emissions of Euro V vehicles

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-11-15

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

  18. Analysis and Measurement of NOx Emissions in Port Auxiliary Vessels

    Directory of Open Access Journals (Sweden)

    German de Melo Rodriguez

    2013-09-01

    Full Text Available This paper is made NOx pollution emitted by port auxiliary vessels, specifically by harbour tugs, due to its unique operating characteristics of operation, require a large propulsion power changes discontinuously, also possess some peculiar technical characteristics, large tonnage and high propulsive power, that differentiate them from other auxiliary vessels of the port. Taking into account all the above features, there are no studies of the NOx emission engines caused by different working regimes of power because engine manufacturers have not measured these emissions across the range of operating power, but usually we only report the pollution produced by its engines to a maximum continuous power.

  19. NOx emission trade. What is the state-of-the-art?

    International Nuclear Information System (INIS)

    Witkamp, J.

    2003-01-01

    In Leiden, Netherlands, 28 November 2002, a symposium was organized on the subject of NOx emission trade in preparation of a NOx emission trade system. In this article an overview is given of the developments so far [nl

  20. Biomass fuel characterization for NOx emissions in cofiring applications

    NARCIS (Netherlands)

    Di Nola, G.

    2007-01-01

    This dissertation investigates the impact of various biomass fuels and combustion conditions on the NOx emissions during biomass co-firing. Fossil fuels dominated the energy scenario since the industrial revolution. However, in the last decades, increasing concerns about their availability and

  1. Biodiesel unsaturation degree effects on diesel engine NOx emissions and cotton wick flame temperature

    OpenAIRE

    Abdullah Mohd Fareez Edzuan; Zhing Sim Shu; Bilong Bugik Clarence

    2017-01-01

    As compared with conventional diesel fuel, biodiesel has better lubricity and lower particulate matter (PM) emissions however nitrogen oxides (NOx) emissions generally increase in biodiesel-fuelled diesel engine. Strict regulation on NOx emissions is being implemented in current Euro 6 standard and it is expected to be tighter in next standard, thus increase of NOx cannot be accepted. In this study, biodiesel unsaturation degree effects on NOx emissions are investigated. Canola, palm and coco...

  2. Intercomparison of NOx emission inventories over East Asia

    Directory of Open Access Journals (Sweden)

    J. Ding

    2017-08-01

    Full Text Available We compare nine emission inventories of nitrogen oxides including four satellite-derived NOx inventories and the following bottom-up inventories for East Asia: REAS (Regional Emission inventory in ASia, MEIC (Multi-resolution Emission Inventory for China, CAPSS (Clean Air Policy Support System and EDGAR (Emissions Database for Global Atmospheric Research. Two of the satellite-derived inventories are estimated by using the DECSO (Daily Emission derived Constrained by Satellite Observations algorithm, which is based on an extended Kalman filter applied to observations from OMI or from GOME-2. The other two are derived with the EnKF algorithm, which is based on an ensemble Kalman filter applied to observations of multiple species using either the chemical transport model CHASER and MIROC-chem. The temporal behaviour and spatial distribution of the inventories are compared on a national and regional scale. A distinction is also made between urban and rural areas. The intercomparison of all inventories shows good agreement in total NOx emissions over mainland China, especially for trends, with an average bias of about 20 % for yearly emissions. All the inventories show the typical emission reduction of 10 % during the Chinese New Year and a peak in December. Satellite-derived approaches using OMI show a summer peak due to strong emissions from soil and biomass burning in this season. Biases in NOx emissions and uncertainties in temporal variability increase quickly when the spatial scale decreases. The analyses of the differences show the importance of using observations from multiple instruments and a high spatial resolution model for the satellite-derived inventories, while for bottom-up inventories, accurate emission factors and activity information are required. The advantage of the satellite-derived approach is that the emissions are soon available after observation, while the strength of the bottom-up inventories is that they include

  3. Atmospheric emission of NOx from mining explosives: A critical review

    Science.gov (United States)

    Oluwoye, Ibukun; Dlugogorski, Bogdan Z.; Gore, Jeff; Oskierski, Hans C.; Altarawneh, Mohammednoor

    2017-10-01

    High-energy materials such as emulsions, slurries and ammonium-nitrate fuel-oil (ANFO) explosives play crucial roles in mining, quarrying, tunnelling and many other infrastructure activities, because of their excellent transport and blasting properties. These explosives engender environmental concerns, due to atmospheric pollution caused by emission of dust and nitrogen oxides (NOx) from blasts, the latter characterised by the average emission factor of 5 kg (t AN explosive)-1. This first-of-its-kind review provides a concise literature account of the formation of NOx during blasting of AN-based explosives, employed in surface operations. We estimate the total NOx emission rate from AN-based explosives as 0.05 Tg (i.e., 5 × 104 t) N per annum, compared to the total global annual anthropogenic NOx emissions of 41.3 × 106 t N y-1. Although minor in the global sense, the large localised plumes from blasting exhibit high NOx concentration (500 ppm) exceeding up to 3000 times the international standards. This emission has profound consequences at mining sites and for adjacent atmospheric environment, necessitating expensive management of exclusion zones. The review describes different types of AN energetic materials for civilian applications, and summarises the essential properties and terminologies pertaining to their use. Furthermore, we recapitulate the mechanisms that lead to the formation of the reactive nitrogen species in blasting of AN-based explosives, review their implications to atmospheric air pollution, and compare the mechanisms with those experienced in other thermal and combustion operations. We also examine the mitigation approaches, including guidelines and operational-control measures. The review discusses the abatement technologies such as the formulation of new explosive mixtures, comprising secondary fuels, spin traps and other additives, in light of their effectiveness and efficiency. We conclude the review with a summary of unresolved problems

  4. Reconciling NOx emissions reductions and ozone trends in ...

    Science.gov (United States)

    Dynamic evaluation seeks to assess the ability of photochemical models to replicate changes in air quality as emissions and other conditions change. When a model fails to replicate an observed change, a key challenge is to discern whether the discrepancy is caused by errors in meteorological simulations, errors in emission magnitudes and changes, or inaccurate responses of simulated pollutant concentrations to emission changes. In this study, the Community Multiscale Air Quality (CMAQ) model is applied to simulate the ozone (O3) change after the NOx SIP Call and mobile emission controls substantially reduced nitrogen oxides (NOx) emissions in the eastern U.S. from 2002 to 2006. For both modeled and observed O3, changes in episode average daily maximal 8-h O3 were highly correlated (R2 = 0.89) with changes in the 95th percentile, although the magnitudes of reductions increased nonlinearly at high percentile O3 concentrations. Observed downward changes in mean NOx (−11.6 to −2.5 ppb) and 8-h O3 (−10.4 to −4.7 ppb) concentrations in metropolitan areas in the NOx SIP Call region were under-predicted by 31%–64% and 26%–66%, respectively. The under-predicted O3 improvements in the NOx SIP Call region could not be explained by adjusting for temperature biases in the meteorological input, or by considering uncertainties in the chemical reaction rate constants. However, the under-prediction in O3 improvements could be alleviated by 5%–31% by constraining NO

  5. Reburning technology - a means to reduce NOx emissions

    International Nuclear Information System (INIS)

    Kremer, H.; Lorra, M.

    1999-01-01

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

  6. The Gothenburg Protocol: NOx emissions problematic for Norway

    International Nuclear Information System (INIS)

    Lind, Oddvar

    2000-01-01

    The Gothenburg Protocol concerns long-range air pollution and is a continuation of earlier protocols and agreements. Its recommendations are based on calculations of where the greatest possible health- and environmental impact is obtained per dollar invested. European countries have done much to reduce the emission of sulphur dioxide. Norway and most other countries, however, have difficulties reducing their emissions of nitrogen oxides. In Norway, the emission of sulphur dioxide must also be substantially reduced, as the tolerance limit for SO2 in nature is low. It is socio-economically profitable for Norway to conform to the Gothenburg Protocol. One of the largest environmental problems in Norway is acid rain and death of fish. Although it is difficult to calculate the exact values of fishing-lakes and of reduced health injuries when the emissions of harmful waste gases are reduced, the profit is very high. 90% of the SO2 pollution in Norway is long-range transported from abroad. Yet Norway must reduce the domestic emissions from 30 000 to 22 000 tonnes the next 10 years. Most of the present emission of SO2 in Norway comes from the production of metals. The reduction goal can be achieved by a combination of improving industrial processes, SO2 cleaning, and reducing the sulphur content of oil. In many European countries, the greatest problem is the increasing emission of NOx and formation of ozone at the ground, which is largely due to the rapidly increasing motor traffic. In Norway, most of the NOx emission comes from the coastal traffic and the fishing fleet, followed by the motor traffic, the petroleum industry and the processing industry. The most cost-effective NOx reductions can be obtained in the North Sea by installing low-NOx gas turbines. In ships, catalytic cleaning of NOx and engine improvements will contribute. On land, the goods traffic can be made more efficient. Most of the emission of ammonia comes from agriculture, where special measures are

  7. Implications of diesel emissions control failures to emission factors and road transport NOx evolution

    Science.gov (United States)

    Ntziachristos, Leonidas; Papadimitriou, Giannis; Ligterink, Norbert; Hausberger, Stefan

    2016-09-01

    Diesel NOx emissions have been at the forefront of research and regulation scrutiny as a result of failures of late vehicle technologies to deliver on-road emissions reductions. The current study aims at identifying the actual emissions levels of late light duty vehicle technologies, including Euro 5 and Euro 6 ones. Mean NOx emission factor levels used in the most popular EU vehicle emission models (COPERT, HBEFA and VERSIT+) are compared with latest emission information collected in the laboratory over real-world driving cycles and on the road using portable emissions measurement systems (PEMS). The comparison shows that Euro 5 passenger car (PC) emission factors well reflect on road levels and that recently revealed emissions control failures do not call for any significant corrections. However Euro 5 light commercial vehicles (LCVs) and Euro 6 PCs in the 2014-2016 period exhibit on road emission levels twice as high as used in current models. Moreover, measured levels vary a lot for Euro 6 vehicles. Scenarios for future evolution of Euro 6 emission factors, reflecting different degree of effectiveness of emissions control regulations, show that total NOx emissions from diesel Euro 6 PC and LCV may correspond from 49% up to 83% of total road transport emissions in 2050. Unless upcoming and long term regulations make sure that light duty diesel NOx emissions are effectively addressed, this will have significant implications in meeting future air quality and national emissions ceilings targets.

  8. Top-down NOx and SO2 emissions simultaneously estimated from different OMI retrievals and inversion frameworks

    Science.gov (United States)

    Qu, Z.; Henze, D. K.; Wang, J.; Xu, X.; Wang, Y.

    2017-12-01

    Quantifying emissions trends of nitrogen oxides (NOx) and sulfur dioxide (SO2) is important for improving understanding of air pollution and the effectiveness of emission control strategies. We estimate long-term (2005-2016) global (2° x 2.5° resolution) and regional (North America and East Asia at 0.5° x 0.667° resolution) NOx emissions using a recently developed hybrid (mass-balance / 4D-Var) method with GEOS-Chem. NASA standard product and DOMINO retrievals of NO2 column are both used to constrain emissions; comparison of these results provides insight into regions where trends are most robust with respect to retrieval uncertainties, and highlights regions where seemingly significant trends are retrieval-specific. To incorporate chemical interactions among species, we extend our hybrid method to assimilate NO2 and SO2 observations and optimize NOx and SO2 emissions simultaneously. Due to chemical interactions, inclusion of SO2 observations leads to 30% grid-scale differences in posterior NOx emissions compared to those constrained only by NO2 observations. When assimilating and optimizing both species in pseudo observation tests, the sum of the normalized mean squared error (compared to the true emissions) of NOx and SO2 posterior emissions are 54-63% smaller than when observing/constraining a single species. NOx and SO2 emissions are also correlated through the amount of fuel combustion. To incorporate this correlation into the inversion, we optimize seven sector-specific emission scaling factors, including industry, energy, residential, aviation, transportation, shipping and agriculture. We compare posterior emissions from inversions optimizing only species' emissions, only sector-based emissions, and both species' and sector-based emissions. In situ measurements of NOx and SO2 are applied to evaluate the performance of these inversions. The impacts of the inversion on PM2.5 and O3 concentrations and premature deaths are also evaluated.

  9. Global NOx emission estimates derived from an assimilation of OMI tropospheric NO2 columns

    Directory of Open Access Journals (Sweden)

    K. Sudo

    2012-03-01

    Full Text Available A data assimilation system has been developed to estimate global nitrogen oxides (NOx emissions using OMI tropospheric NO2 columns (DOMINO product and a global chemical transport model (CTM, the Chemical Atmospheric GCM for Study of Atmospheric Environment and Radiative Forcing (CHASER. The data assimilation system, based on an ensemble Kalman filter approach, was applied to optimize daily NOx emissions with a horizontal resolution of 2.8° during the years 2005 and 2006. The background error covariance estimated from the ensemble CTM forecasts explicitly represents non-direct relationships between the emissions and tropospheric columns caused by atmospheric transport and chemical processes. In comparison to the a priori emissions based on bottom-up inventories, the optimized emissions were higher over eastern China, the eastern United States, southern Africa, and central-western Europe, suggesting that the anthropogenic emissions are mostly underestimated in the inventories. In addition, the seasonality of the estimated emissions differed from that of the a priori emission over several biomass burning regions, with a large increase over Southeast Asia in April and over South America in October. The data assimilation results were validated against independent data: SCIAMACHY tropospheric NO2 columns and vertical NO2 profiles obtained from aircraft and lidar measurements. The emission correction greatly improved the agreement between the simulated and observed NO2 fields; this implies that the data assimilation system efficiently derives NOx emissions from concentration observations. We also demonstrated that biases in the satellite retrieval and model settings used in the data assimilation largely affect the magnitude of estimated emissions. These dependences should be carefully considered for better understanding NOx sources from top-down approaches.

  10. Computations of NOx emissions of domestic boilers

    Energy Technology Data Exchange (ETDEWEB)

    Thevenin, D. [Ecole Centrale de Paris, 92 - Chatenay-Malabry (France). EM2C Lab.; Gicquel, O.; Darabiha, N.

    2001-07-01

    Due to severe regulations concerning pollutant emissions, practical devices using combustion to release energy must be designed from the start using accurate, predictive numerical tools. A partially premixed methane/air flame in a two-dimensional configuration is investigated in this work. This configuration is close to those used in real domestic gas boilers. The flame structure and flow pattern are calculated using complex chemistry and detailed transport models. A post-processing method is then used to predict NO emission. Computations are performed for two configurations. The two cases have the same primary and secondary mass flow-rates and equivalence ratio. The only difference between them is the introduction of an insert inside the primary injector. Both results have been compared to measurements. Calculations are found to be in good agreement with the flame shapes observed experimentally. The classical burner shows a Bunsen-type flame while the one with an insert has a totally different shape (butterfly-type flame). NO emission levels are also well predicted in both configurations. The butterfly flame induces a reduction in NO emission. This reduction seems to be due to the increased mixing between the burnt gases and the secondary air jet, which homogenizes the temperature distribution and reduces the maximum temperature. (orig.)

  11. 40 CFR 60.4380 - How are excess emissions and monitor downtime defined for NOX?

    Science.gov (United States)

    2010-07-01

    ... downtime defined for NOX? 60.4380 Section 60.4380 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... downtime defined for NOX? For the purpose of reports required under § 60.7(c), periods of excess emissions... NOX control will also be considered an excess emission. (2) A period of monitor downtime is any unit...

  12. Effects of temperature-dependent NOx emissions on continental ozone production

    Science.gov (United States)

    Romer, Paul S.; Duffey, Kaitlin C.; Wooldridge, Paul J.; Edgerton, Eric; Baumann, Karsten; Feiner, Philip A.; Miller, David O.; Brune, William H.; Koss, Abigail R.; de Gouw, Joost A.; Misztal, Pawel K.; Goldstein, Allen H.; Cohen, Ronald C.

    2018-02-01

    Surface ozone concentrations are observed to increase with rising temperatures, but the mechanisms responsible for this effect in rural and remote continental regions remain uncertain. Better understanding of the effects of temperature on ozone is crucial to understanding global air quality and how it may be affected by climate change. We combine measurements from a focused ground campaign in summer 2013 with a long-term record from a forested site in the rural southeastern United States, to examine how daily average temperature affects ozone production. We find that changes to local chemistry are key drivers of increased ozone concentrations on hotter days, with integrated daily ozone production increasing by 2.3 ppb °C-1. Nearly half of this increase is attributable to temperature-driven increases in emissions of nitrogen oxides (NOx), most likely by soil microbes. The increase of soil NOx emissions with temperature suggests that ozone will continue to increase with temperature in the future, even as direct anthropogenic NOx emissions decrease dramatically. The links between temperature, soil NOx, and ozone form a positive climate feedback.

  13. Effects of temperature-dependent NOx emissions on continental ozone production

    Directory of Open Access Journals (Sweden)

    P. S. Romer

    2018-02-01

    Full Text Available Surface ozone concentrations are observed to increase with rising temperatures, but the mechanisms responsible for this effect in rural and remote continental regions remain uncertain. Better understanding of the effects of temperature on ozone is crucial to understanding global air quality and how it may be affected by climate change. We combine measurements from a focused ground campaign in summer 2013 with a long-term record from a forested site in the rural southeastern United States, to examine how daily average temperature affects ozone production. We find that changes to local chemistry are key drivers of increased ozone concentrations on hotter days, with integrated daily ozone production increasing by 2.3 ppb °C−1. Nearly half of this increase is attributable to temperature-driven increases in emissions of nitrogen oxides (NOx, most likely by soil microbes. The increase of soil NOx emissions with temperature suggests that ozone will continue to increase with temperature in the future, even as direct anthropogenic NOx emissions decrease dramatically. The links between temperature, soil NOx, and ozone form a positive climate feedback.

  14. Impacts of biogenic emissions of VOC and NOx on tropospheric ozone during summertime in eastern China.

    Science.gov (United States)

    Wang, Qin'geng; Han, Zhiwei; Wang, Tijian; Zhang, Renjian

    2008-05-20

    This study is intended to understand and quantify the impacts of biogenic emissions of volatile organic compounds (VOC) and nitrogen oxides (NO(x)) on the formation of tropospheric ozone during summertime in eastern China. The model system consists of the non-hydrostatic mesoscale meteorological model (MM5) and a tropospheric chemical and transport model (TCTM) with the updated carbon-bond chemical reaction mechanism (CBM-IV). The spatial resolution of the system domain is 30 km x 30 km. The impacts of biogenic emissions are investigated by performing simulations (36 h) with and without biogenic emissions, while anthropogenic emissions are constant. The results indicate that biogenic emissions have remarkable impacts on surface ozone in eastern China. In big cities and their surrounding areas, surface ozone formation tends to be VOC-limited. The increase in ozone concentration by biogenic VOC is generally 5 ppbv or less, but could be more than 10 ppbv or even 30 ppbv in some local places. The impacts of biogenic NO(x) are different or even contrary in different regions, depending on the relative availability of NO(x) and VOC. The surface ozone concentrations reduced or increased by the biogenic NO(x) could be as much as 10 ppbv or 20 ppbv, respectively. The impacts of biogenic emissions on ozone aloft are generally restricted to the boundary layer and generally more obvious during the daytime than during the nighttime. This study is useful for understanding the role of biogenic emissions and for planning strategies for surface ozone abatement in eastern China. Due to limitations of the emission inventories used and the highly non-linear nature of zone formation, however, some uncertainties remain in the results.

  15. Global observation of EKC hypothesis for CO2, SOx and NOx emission: A policy understanding for climate change mitigation in Bangladesh

    International Nuclear Information System (INIS)

    Danesh Miah, Md.; Farhad Hossain Masum, Md.; Koike, Masao

    2010-01-01

    Environmental Kuznets Curve (EKC) hypothesis is critical to understanding the developmental path of a nation in relation to its environment. How the effects of economic development processes dictate environmental changes can be found through the study of EKC. To understand the EKC phenomena for climate change, this study was undertaken by reviewing the available literature. As CO 2 , SO x and NO x are the significant greenhouse gases (GHG) responsible for global warming, thus leading to climate change, the study focused on those GHGs for EKC consideration. With an understanding of the different EKC trajectories, an attempt was made to determine the implications for the economic development of Bangladesh in regards to the EKC. It was shown that EKC for CO 2 was following a monotonous straight line in most cases. SO x were shown to follow the full trajectory of the EKC in most situations and NO x was shown the hope only for the developed countries getting the low-income turning point. The type of economic policy that Bangladesh should follow in regards to the discussed pollutants and sources is also revealed. From these discussions, contributions to policy stimulation in Bangladesh are likely to be made.

  16. Update of NOx emission temporal profiles using CMAQ-HDDM

    Science.gov (United States)

    Bae, C.; Lee, J. B.; Kim, H. C.; Kim, B. U.; Kim, S.

    2017-12-01

    This study demonstrates the impact of revised temporal profiles of NOx emissions on air quality simulations in the Seoul Metropolitan Area (SMA), South Korea. Air pollutants such as ozone and nitrogen oxides can be harmful to the human body even with short-term exposure. Since most of air quality models use predefined temporal profiles which are often outdated or taken from different chemical environment, providing accurate temporal variation of emissions are challenging in prediction of correct local air quality. Considering secondary formation of pollutants are important in mega cities and temporal variations of emissions are not coincident with those of resultant concentrations, we utilized CMAQ-HDDM to link emissions and consequential concentrations from different time steps. Base simulations were conducted using WRF, SMOKE, and CMAQ modeling frame using CREATE 2015 and CAPSS 2013 emissions inventories for East Asia and South Korea, respectively. With current modeling system, modeled NOx concentrations underestimate 4% in the daytime (10-16 LST), but overestimate 30% in the nighttime during May to August 2015. Applying revised temporal profiles based on HDDM sensitivities, model performance was improved significantly. We conclude that the proposed temporal allocation method can be useful to reduce the model-observation discrepancies when the activity data for emission sources are difficult to obtain with a bottom-up approach.

  17. NOx Emission Reduction by Oscillating Combustion

    Energy Technology Data Exchange (ETDEWEB)

    John C. Wagner

    2004-03-31

    High-temperature, natural gas-fired furnaces, especially those fired with preheated air, produce large quantities of NO{sub x} per ton of material processed. Regulations on emissions from industrial furnaces are becoming increasingly more stringent. In addition, competition is forcing operators to make their furnaces more productive and/or efficient. Switching from preheated air to industrial oxygen can increase efficiency and reduce NO{sub x}, but oxygen is significantly more costly than air and may not be compatible with the material being heated. What was needed, and what was developed during this project, is a technology that reduces NO{sub x} emissions while increasing furnace efficiency for both air- and oxy-fired furnaces. Oscillating combustion is a retrofit technology that involves the forced oscillation of the fuel flow rate to a furnace. These oscillations create successive, fuel-rich and fuel-lean zones within the furnace. Heat transfer from the flame to the load increases due to the more luminous fuel-rich zones, a longer overall flame length, and the breakup of the thermal boundary layer. The increased heat transfer shortens heat up times, thereby increasing furnace productivity, and reduces the heat going up the stack, thereby increasing efficiency. The fuel-rich and fuel-lean zones also produce substantially less NO{sub x} than firing at a constant excess air level. The longer flames and higher heat transfer rate reduces overall peak flame temperature and thus reduces additional NO{sub x} formation from the eventual mixing of the zones and burnout of combustibles from the rich zones. This project involved the development of hardware to implement oscillating combustion on an industrial scale, the laboratory testing of oscillating combustion on various types of industrial burners, and the field testing of oscillating combustion on several types of industrial furnace. Before laboratory testing began, a market study was conducted, based on the

  18. NOx Emission Reduction by Oscillating combustion

    Energy Technology Data Exchange (ETDEWEB)

    Institute of Gas Technology

    2004-01-30

    High-temperature, natural gas-fired furnaces, especially those fired with preheated air, produce large quantities of NO{sub x} per ton of material processed. Regulations on emissions from industrial furnaces are becoming increasingly more stringent. In addition, competition is forcing operators to make their furnaces more productive and/or efficient. Switching from preheated air to industrial oxygen can increase efficiency and reduce NO{sub x}, but oxygen is significantly more costly than air and may not be compatible with the material being heated. What was needed, and what was developed during this project, is a technology that reduces NO{sub x} emissions while increasing furnace efficiency for both air- and oxy-fired furnaces. Oscillating combustion is a retrofit technology that involves the forced oscillation of the fuel flow rate to a furnace. These oscillations create successive, fuel-rich and fuel-lean zones within the furnace. Heat transfer from the flame to the load increases due to the more luminous fuel-rich zones, a longer overall flame length, and the breakup of the thermal boundary layer. The increased heat transfer shortens heat up times, thereby increasing furnace productivity, and reduces the heat going up the stack, thereby increasing efficiency. The fuel-rich and fuel-lean zones also produce substantially less NO{sub x} than firing at a constant excess air level. The longer flames and higher heat transfer rate reduces overall peak flame temperature and thus reduces additional NO{sub x} formation from the eventual mixing of the zones and burnout of combustibles from the rich zones. This project involved the development of hardware to implement oscillating combustion on an industrial scale, the laboratory testing of oscillating combustion on various types of industrial burners, and the field testing of oscillating combustion on several types of industrial furnace. Before laboratory testing began, a market study was conducted, based on the

  19. Emission of SO2 and NOx from power plants

    International Nuclear Information System (INIS)

    Boll Illerup, J.; Bruun, H.G.

    2003-01-01

    The European Parliament and the European Council have issued the directive on the limitation of emissions of certain pollutants into the air from large combustion plants (LCP directive, 2001/80/EC of 23 October 2001). The objective of the directive is to control and reduce emissions of SO 2 and NO X , to keep depositions and concentrations below the critical loads and levels. The directive was implemented in Denmark in 2002 and replaces Statutory Order no. 689 of 15 October 1990 about reduction of SO 2 , NO X and particulate matter from large combustion plants. The purpose of the project is to evaluate whether the emission limit values laid down by the LCP directive will - to the same extent as the Statutory Order from the Danish Energy Agency on emission quota for power plants - ensure the fulfilment of Denmark's obligations in relation to the EU directive on national emission ceilings and the similar obligations in the UNECE Gothenburg Protocol. The emission ceilings for Denmark in 2010 are 55,000 tons SO 2 and 127,000 tons NO X The project includes the power plants regulated by the quota law, which means all plants larger than 25 MWe. The emissions are calculated for three production scenarios: 1) the national supply scenario where the produced electricity equals the electricity used in Denmark, 2) the low price scenario with little export of electricity in the ELSAM area and little import in the Energi E2 area, and 3) the high price scenario with large export of electricity. The emissions are estimated from emission factors based on the LCP directive and emission factors based on a valuation of the actual concentration of SO, and NOX in the flue gas. If the emissions from the power plants just comply with the emission limit values given in the directive the total emissions of both SO 2 and NO X are higher than the quota for all three scenarios. If the emissions are assumed to depend on the actual technological status in 2010 at individual plants, e.g. installed

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-06-01

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

  1. Constraints on ship NOx emissions in Europe using OMI NO2 observations

    Science.gov (United States)

    Vinken, G. C. M.; Boersma, K. F.

    2012-04-01

    About 90% of world trade is transported by oceangoing ships, and seaborne trade has been shown to have increased by about 5% per year in the past decade. Global ship traffic is currently not regulated under international treaties (e.g. Kyoto protocol) and ships are still allowed to burn low-grade bunker fuel. As a result, ships emit large quantities of nitrogen oxides (NOx = NO + NO2), important precursors for ozone (O3) and particulate matter formation. Previous studies indicated that the global NOx emissions from shipping are in the range 3.0-10.4 Tg N per year (15-30% of total global NOx emissions). Because most ships sail within 400 km of the coast, it is important to understand the contribution of ship emissions to atmospheric composition in the densely populated coastal regions. Chemistry Transport Models (CTMs), in combination with emission inventories, are used to simulate atmospheric concentrations of air pollutants to assess the impact of ship emissions. However, these bottom-up inventories, based on extrapolation of a few engine measurements and strong assumptions, suffer from large uncertainties. In this study we provide top-down constraints on ship NOx emissions in Europe using satellite observations of NO2 columns. We use the nested version of the GEOS-Chem model (0.5°-0.667°) to simulate tropospheric NO2 columns over Europe for the years 2005-2006, using our plume-in-grid treatment of ship NOx emissions. We improve the NO2 retrievals from the Ozone Monitoring Instrument (OMI v2.0) by replacing the coarse a priori (TM4) vertical NO2 profiles (2°-3°) with the high-resolution GEOS-Chem profiles. This ensures consistency between the retrievals and model simulations. GEOS-Chem simulations of tropospheric NO2 columns show remarkable quantitative agreement with the observed OMI columns over Europe (R2=0.89, RMS difference < 0.2-1015 molec. cm-2), providing confidence in the ability of the model to simulate NO2 pollution over the European mainland. We

  2. High NO2/NOx emissions downstream of the catalytic diesel particulate filter: An influencing factor study.

    Science.gov (United States)

    He, Chao; Li, Jiaqiang; Ma, Zhilei; Tan, Jianwei; Zhao, Longqing

    2015-09-01

    Diesel vehicles are responsible for most of the traffic-related nitrogen oxide (NOx) emissions, including nitric oxide (NO) and nitrogen dioxide (NO2). The use of after-treatment devices increases the risk of high NO2/NOx emissions from diesel engines. In order to investigate the factors influencing NO2/NOx emissions, an emission experiment was carried out on a high pressure common-rail, turbocharged diesel engine with a catalytic diesel particulate filter (CDPF). NO2 was measured by a non-dispersive ultraviolet analyzer with raw exhaust sampling. The experimental results show that the NO2/NOx ratios downstream of the CDPF range around 20%-83%, which are significantly higher than those upstream of the CDPF. The exhaust temperature is a decisive factor influencing the NO2/NOx emissions. The maximum NO2/NOx emission appears at the exhaust temperature of 350°C. The space velocity, engine-out PM/NOx ratio (mass based) and CO conversion ratio are secondary factors. At a constant exhaust temperature, the NO2/NOx emissions decreased with increasing space velocity and engine-out PM/NOx ratio. When the CO conversion ratios range from 80% to 90%, the NO2/NOx emissions remain at a high level. Copyright © 2015. Published by Elsevier B.V.

  3. CONTROL OF NOX EMISSIONS FROM U.S. COAL-FIRED ELECTRIC UTILITY BOILERS

    Science.gov (United States)

    The paper discusses the control of nitrogen oxide (NOx) emissions from U.S. coal-fired electric utility boilers. (NOTE: In general, NOx control technologies are categorized as being either primary or secondary control technologies. Primary technologies reduce the amount of NOx pr...

  4. Impacts of the abolition of NOx emission trade; Effecten van de afschaffing van NOx- emissiehandel

    Energy Technology Data Exchange (ETDEWEB)

    Kroon, P. [ECN Beleidsstudies, Petten (Netherlands)

    2012-09-15

    The consequences of abolishing the NOx emission trade have been analyzed for the installations that are covered by BEMS legislation (Dutch decree on emission limits for medium-sized combustion plants). The following aspects have been analyzed: What are the enforcement costs if these installations need to comply with BEMS requirements as of 2014?; How are these costs distributed across the various sectors and in particular for the sectors of onshore/offshore gas and oil extraction, greenhouse horticulture and hospitals?; To what extent can costs be lowered by allowing a 2-,3- or 5-year delay of the implementation date for existing installations in BEMS? To answer the above questions, data were used from the NEA (Netherlands Emission Authority) at sector level. Model calculations were conducted to determine the costs and effects [Dutch] De gevolgen van de afschaffing van NOx-emissiehandel zijn geanalyseerd voor het installatiepark dat terugvalt op BEMS-wetgeving (Besluit emissie-eisen middelgrote stookinstallaties). De volgende zaken zijn geanalyseerd: Wat zijn de nalevingskosten indien vanaf 2014 deze installaties aan de BEMS-eisen moeten voldoen?; Hoe zijn deze kosten verdeeld over de verschillende sectoren en in het bijzonder voor de sectoren offshore/onshore gas- en oliewinning, de glastuinbouw en ziekenhuizen?; In hoeverre zijn de kosten te verlagen door 2, 3 of 5 jaar uitstel te geven ten opzichte van de implementatiedatum voor bestaande installaties in BEMS? Voor het beantwoorden van de bovenstaande vragen is gebruik gemaakt van gegevens van de NEa (Nederlandse Emissie autoriteit) op sectorniveau. Met modelberekeningen zijn hiermee kosten en effecten bepaald.

  5. Worldwide biogenic soil NOx emissions inferred from OMI NO2 observations

    NARCIS (Netherlands)

    Vinken, G.C.M.; Boersma, K.F.; Maasakkers, J.D.; Adon, M.; Martin, R.V.

    2014-01-01

    Biogenic NOx emissions from soils are a large natural source with substantial uncertainties in global bottom-up estimates (ranging from 4 to 15 Tg N yr-1). We reduce this range in emission estimates, and present a top-down soil NOx emission inventory for 2005 based on retrieved tropospheric NO2

  6. Real Driving NOx Emissions of European Trucks and Detection of Manipulated Emission Systems

    Science.gov (United States)

    Pöhler, Denis; Adler, Tim; Krufczik, Chsristopher; Horbanski, Martin; Lampel, Johannes; Platt, Ulrich

    2017-04-01

    Nitrogen dioxide (NO2) is the most problematic pollutant in Europe and many other countries. NO2 has a negative impact for the health and the environment, and in most European cities the currently allowed mean annual limit of 40μg/m3 is exceeded. Vehicles, especially Diesel, are the most relevant source. They emit NOx (NO + NO2), and NO can also be converted to NO2 in the atmosphere. Thus vehicle NOx emissions are regulated in the EU with the EURO Norm Standard (e.g. EURO 6 since 1.1.2013 for trucks with 400mg/kWh). Trucks achieve these low emissions with complex emission after treatment systems. All EURO 6 trucks and almost all EURO 5 trucks use the SCR system consuming AdBlue to reduce the NOx emissions. Since the diesel emission scandal for cars, it is well known that real driving emissions (RDE) can be several times higher that the EURO Norm Standard. The main problem is that RDE are only randomly investigated. Here we present a study of NOx RDE of more than 250 randomly chosen trucks on German highways. The measurements were performed with a newly developed mobile NOx-ICAD + CO2 -instrument applying the plume chasing measurement principle, where the pollutants are investigated in the emission plume and were converted to emission factors to be compared to the EURO standard. For most trucks the brand, the model name, the country of registration and its EURO class could be determined and used in a statistical analysis. The observed NOx emission data show that typical truck RDE are in the range of the expected EURO Norm or slightly higher. However, almost every fourth truck from Eastern Europe show emissions much higher that the EURO Norm. This was not observed for German trucks. As the emissions increase up to a factor of 5 to 10 these view trucks contribute significantly to the air pollution. These high emissions clearly indicate a defect emission treatment system. Most likely it indicates illegal manipulated emissions systems where the AdBlue injection is

  7. Comparison and evaluation of anthropogenic emissions of SO2 and NOx over China

    Science.gov (United States)

    Li, Meng; Klimont, Zbigniew; Zhang, Qiang; Martin, Randall V.; Zheng, Bo; Heyes, Chris; Cofala, Janusz; Zhang, Yuxuan; He, Kebin

    2018-03-01

    Bottom-up emission inventories provide primary understanding of sources of air pollution and essential input of chemical transport models. Focusing on SO2 and NOx, we conducted a comprehensive evaluation of two widely used anthropogenic emission inventories over China, ECLIPSE and MIX, to explore the potential sources of uncertainties and find clues to improve emission inventories. We first compared the activity rates and emission factors used in two inventories and investigated the reasons of differences and the impacts on emission estimates. We found that SO2 emission estimates are consistent between two inventories (with 1 % differences), while NOx emissions in ECLIPSE's estimates are 16 % lower than those of MIX. The FGD (flue-gas desulfurization) device penetration rate and removal efficiency, LNB (low-NOx burner) application rate and abatement efficiency in power plants, emission factors of industrial boilers and various vehicle types, and vehicle fleet need further verification. Diesel consumptions are quite uncertain in current inventories. Discrepancies at the sectorial and provincial levels are much higher than those of the national total. We then examined the impacts of different inventories on model performance by using the nested GEOS-Chem model. We finally derived top-down emissions by using the retrieved columns from the Ozone Monitoring Instrument (OMI) compared with the bottom-up estimates. High correlations were observed for SO2 between model results and OMI columns. For NOx, negative biases in bottom-up gridded emission inventories (-21 % for MIX, -39 % for ECLIPSE) were found compared to the satellite-based emissions. The emission trends from 2005 to 2010 estimated by two inventories were both consistent with satellite observations. The inventories appear to be fit for evaluation of the policies at an aggregated or national level; more work is needed in specific areas in order to improve the accuracy and robustness of outcomes at finer spatial

  8. Comparison and evaluation of anthropogenic emissions of SO2 and NOx over China

    Directory of Open Access Journals (Sweden)

    M. Li

    2018-03-01

    Full Text Available Bottom-up emission inventories provide primary understanding of sources of air pollution and essential input of chemical transport models. Focusing on SO2 and NOx, we conducted a comprehensive evaluation of two widely used anthropogenic emission inventories over China, ECLIPSE and MIX, to explore the potential sources of uncertainties and find clues to improve emission inventories. We first compared the activity rates and emission factors used in two inventories and investigated the reasons of differences and the impacts on emission estimates. We found that SO2 emission estimates are consistent between two inventories (with 1 % differences, while NOx emissions in ECLIPSE's estimates are 16 % lower than those of MIX. The FGD (flue-gas desulfurization device penetration rate and removal efficiency, LNB (low-NOx burner application rate and abatement efficiency in power plants, emission factors of industrial boilers and various vehicle types, and vehicle fleet need further verification. Diesel consumptions are quite uncertain in current inventories. Discrepancies at the sectorial and provincial levels are much higher than those of the national total. We then examined the impacts of different inventories on model performance by using the nested GEOS-Chem model. We finally derived top-down emissions by using the retrieved columns from the Ozone Monitoring Instrument (OMI compared with the bottom-up estimates. High correlations were observed for SO2 between model results and OMI columns. For NOx, negative biases in bottom-up gridded emission inventories (−21 % for MIX, −39 % for ECLIPSE were found compared to the satellite-based emissions. The emission trends from 2005 to 2010 estimated by two inventories were both consistent with satellite observations. The inventories appear to be fit for evaluation of the policies at an aggregated or national level; more work is needed in specific areas in order to improve the accuracy and robustness of

  9. Spatio-temporal variability in isotopic signatures of atmospheric NOx emissions from vehicles

    Science.gov (United States)

    Miller, D. J.; Wojtal, P.; O'Connor, M.; Clark, S.; Hastings, M. G.

    2015-12-01

    Atmospheric nitrogen oxides (NOx = NO + NO2) play key roles in atmospheric chemistry and radiative forcing. Their oxidation products, nitric acid or nitrate, have significant contributions to nitrogen (N) deposition, with implications for ecosystem health. On-road vehicle NOx sources currently dominate U.S. anthropogenic emission budgets, yet vehicle NOx emissions contributions to local and regional N deposition patterns are highly uncertain. NOx isotopic signatures offer a potentially valuable observational tool to trace source contributions to N deposition. We characterize the spatio-temporal variability of vehicle NOx emission isotopic signatures with a field and laboratory-verified technique for actively capturing NOx in solution to quantify the nitrogen isotopic composition (δ15N-NOx) to within ±1.5‰ (1σ) precision. We present a novel combination of on-road mobile and stationary urban δ15N-NOx measurements at minutes to hourly resolution along with NOx and CO2 concentration measurements. We evaluate spatial gradients of δ15N-NOx on U.S. Northeast and Midwest highways, including six urban metropolitan areas and rural interstate highways during summer and autumn. We also assess on-road diurnal δ15N-NOx variations over ~800 km driving distance in Providence, RI by targeting the upwind footprint of urban background measurements to distinguish background and source NOx. We observe on-road δ15N-NOx signatures range from -3 to -10‰ under different traffic conditions in the U.S. Northeast and Midwest. On-road δ15N-NOx daytime variations from -3 to -6‰ agree well with simultaneous urban background sampling in Providence, RI, suggesting that vehicles dominate NOx emissions in this region. We use these datasets to estimate the range of representative δ15N-NOx source signatures for U.S. vehicle fleet-integrated emission plumes. Our novel approach suggests that previously reported isotopic signatures for vehicle NOx are not necessarily representative. These

  10. 40 CFR 75.17 - Specific provisions for monitoring emissions from common, bypass, and multiple stacks for NOX...

    Science.gov (United States)

    2010-07-01

    ... emissions from common, bypass, and multiple stacks for NOX emission rate. 75.17 Section 75.17 Protection of..., and multiple stacks for NOX emission rate. Notwithstanding the provisions of paragraphs (a), (b), (c... this part to meet the monitoring and reporting requirements of a State or federal NOX mass emission...

  11. Evaluation of NOX emissions from TVA coal-fired power plants

    International Nuclear Information System (INIS)

    Jones, J.W.; Stamey-Hall, S.

    1991-01-01

    The paper gives results of a preliminary evaluation of nitrogen oxide (NOx) emissions from 11 Tennessee Valley Authority (TVA) coal-fired power plants. Current EPA AP-42 emission factors for NOx from coal-fired utility boilers do not account for variations either in these emissions as a function of generating unit load, or in designs of boilers of the same general type, particularly wall-fired boilers. The TVA has compiled short-term NOx emissions data from 30 units at 11 TVA coal-fired plants. These units include cyclone, cell burner, single wall, opposed wall, single tangential, and twin tangential boiler firing designs. Tests were conducted on 29 of the 30 units at high load; 18 were also tested at reduced load. NOx emissions rates were calculated for each test and compared to the calculated rate for each boiler type using AP-42. Preliminary analysis indicates that: (1) TVA cyclone-fired units emit more NOx than estimated using AP-42; (2) TVA cell burner units emit considerably more NOx than estimated; (3) most TVA single-wall-fired units emit slightly more NOx than estimated; (4) most TVA single-furnace tangentially fired units emit less NOx than estimated at high load, but the same as (or more than) estimated at reduced load; and (5) most TVA twin-furnace tangentially fired units, at high load, emit slightly more NOx than estimated using AP-42

  12. NOx Emissions Performance and Correlation Equations for a Multipoint LDI Injector

    Science.gov (United States)

    He, Zhuohui J.; Chang, Clarence T.; Follen, Caitlin E.

    2015-01-01

    Lean Direct Injection (LDI) is a combustor concept that reduces nitrogen oxides (NOx) emissions. This paper looks at a 3-zone multipoint LDI concept developed by Parker Hannifin Corporation. The concept was tested in a flame-tube test facility at NASA Glenn Research Center. Due to test facility limitations, such as inlet air temperature and pressure, the flame-tube test was not able to cover the full set of engine operation conditions. Three NOx correlation equations were developed based on assessing NOx emissions dependencies on inlet air pressure (P3), inlet air temperature (T3), and fuel air equivalence ratio (?) to estimate the NOx emissions at the unreachable high engine power conditions. As the results, the NOx emissions are found to be a strong function of combustion inlet air temperature and fuel air equivalence ratio but a weaker function of inlet air pressure. With these three equations, the NOx emissions performance of this injector concept is calculated as a 66% reduction relative to the ICAO CAEP-6 standard using a 55:1 pressure-ratio engine cycle. Uncertainty in the NOx emissions estimation increases as the extrapolation range departs from the experimental conditions. Since maximum inlet air pressure tested was less than 50% of the full power engine inlet air pressure, a future experiment at higher inlet air pressure conditions is needed to confirm the NOx emissions dependency on inlet air pressure.

  13. Continuous reduction of cyclic adsorbed and desorbed NO(x) in diesel emission using nonthermal plasma.

    Science.gov (United States)

    Kuwahara, Takuya; Nakaguchi, Harunobu; Kuroki, Tomoyuki; Okubo, Masaaki

    2016-05-05

    Considering the recent stringent regulations governing diesel NO(x) emission, an aftertreatment system for the reduction of NO(x) in the exhaust gas has been proposed and studied. The proposed system is a hybrid method combining nonthermal plasma and NOx adsorbent. The system does not require precious metal catalysts or harmful chemicals such as urea and ammonia. In the present system, NO(x) in diesel emission is treated by adsorption and desorption by adsorbent as well as nonthermal plasma reduction. In addition, the remaining NO(x) in the adsorbent is desorbed again in the supplied air by residual heat. The desorbed NO(x) in air recirculates into the intake of the engine, and this process, i.e., exhaust gas components' recirculation (EGCR) achieves NO(x) reduction. Alternate utilization of two adsorption chambers in the system can achieve high-efficiency NO(x) removal continuously. An experiment with a stationary diesel engine for electric power generation demonstrates an energy efficiency of 154 g(NO2)/kWh for NO(x) removal and continuous NO(x) reduction of 70.3%. Considering the regulation against diesel emission in Japan, i.e., the new regulation to be imposed on vehicles of 3.5-7.5 ton since 2016, the present aftertreatment system fulfills the requirement with only 1.0% of engine power. Copyright © 2016. Published by Elsevier B.V.

  14. Biodiesel unsaturation degree effects on diesel engine NOx emissions and cotton wick flame temperature

    Directory of Open Access Journals (Sweden)

    Abdullah Mohd Fareez Edzuan

    2017-01-01

    Full Text Available As compared with conventional diesel fuel, biodiesel has better lubricity and lower particulate matter (PM emissions however nitrogen oxides (NOx emissions generally increase in biodiesel-fuelled diesel engine. Strict regulation on NOx emissions is being implemented in current Euro 6 standard and it is expected to be tighter in next standard, thus increase of NOx cannot be accepted. In this study, biodiesel unsaturation degree effects on NOx emissions are investigated. Canola, palm and coconut oils are selected as the feedstock based on their unsaturation degree. Biodiesel blends of B20 were used to fuel a single cylinder diesel engine and exhaust emissions were sampled directly at exhaust tailpipe with a flue gas analyser. Biodiesel flame temperature was measured from a cotton wick burned in simple atmospheric conditions using a thermocouple. Fourier transform infrared (FTIR spectrometer was also used to identify the functional groups presence in the biodiesel blends. Oxygen content in biodiesel may promote complete combustion as the NOx emissions and flame temperatures were increased while the carbon monoxide (CO emissions were decreased for all biodiesel blends. It is interesting to note that the NOx emissions and flame temperatures were directly proportional with biodiesel unsaturation degree. It might be suggested that apart from excess oxygen and free radical formation, higher NOx emissions can also be caused by the elevated flame temperatures due to the presence of double bonds in unsaturated biodiesel.

  15. The challenge to NOx emission control for heavy-duty diesel vehicles in China

    Directory of Open Access Journals (Sweden)

    K. B. He

    2012-10-01

    Full Text Available China's new "Twelfth Five-Year Plan" set a target for total NOx emission reduction of 10% for the period of 2011–2015. Heavy-duty diesel vehicles (HDDVs have been considered a major contributor to NOx emissions in China. Beijing initiated a comprehensive vehicle test program in 2008. This program included a sub-task for measuring on-road emission profiles of hundreds of HDDVs using portable emission measurement systems (PEMS. The major finding is that neither the on-road distance-specific (g km−1 nor brake-specific (g kWh−1 NOx emission factors for diesel buses and heavy-duty diesel trucks improved in most cases as emission standards became more stringent. For example, the average NOx emission factors for Euro II, Euro III and Euro IV buses are 11.3 ± 3.3 g km−1, 12.5 ± 1.3 g km−1, and 11.8 ± 2.0 g km−1, respectively. No statistically significant difference in NOx emission factors was observed between Euro II and III buses. Even for Euro IV buses equipped with SCR systems, the NOx emission factors are similar to Euro III buses. The data regarding real-time engine performance of Euro IV buses suggest the engine certification cycles did not reflect their real-world operating conditions. These new on-road test results indicate that previous estimates of total NOx emissions for HDDV fleet may be significantly underestimated. The new estimate in total NOx emissions for the Beijing HDDV fleet in 2009 is 37.0 Gg, an increase of 45% compared to the previous study. Further, we estimate that the total NOx emissions for the national HDDV fleet in 2009 are approximately 4.0 Tg, higher by 1.0 Tg (equivalent to 18% of total NOx emissions for vehicle fleet in 2009 than that estimated in the official report. This would also result in 4% increase in estimation of national anthropogenic NOx emissions. More effective control measures (such as promotion of CNG buses and a new in-use compliance testing program are urged to secure the goal of total NOx

  16. Experimental Validation of a Virtual Engine-Out NOx Sensor for Diesel Emission Control

    NARCIS (Netherlands)

    Escobar Valdivieso, D.; Mentink, P.; Külah, S.; Forrai, A.; Willems, F.P.T.

    2017-01-01

    Motivated by automotive emissions legislations, a Virtual NOx sensor is developed. This virtual sensor consists of a real-time, phenomenological model that computes engine-out NOx by using the measured in-cylinder pressure signal from a single cylinder as its main input. The implementation is made

  17. Characterization of NOx emission in the suburbs of Tokyo based on simultaneous and real-time observations of atmospheric Ox and NOx

    Science.gov (United States)

    Matsumoto, J.

    2013-12-01

    Nitrogen oxides, NOx (NO, NO2), and volatile organic compounds, VOCs, are important as precursors of photochemical oxidants (tropospheric ozone, O3). To predict and control photochemical oxidants, NOx emission should be captured precisely. In addition, the ratio of NO2/NOx in the exhaust gas is also important as the initial balance between NO and NO2 in the atmosphere. Monitoring the NO2/NOx ratio in the exhaust gases is essential. Especially, the influence of the NOx emission on the real atmosphere should be explored. However, conversion reactions among NO, NO2 and O3 are typically in the time scale of minutes. The NO2/NOx ratio can change rapidly just after emission. Real-time observations of these compounds in the second time scale are essential. In view of photochemical oxidant, near emission sources of NO, ozone concentration can be easily perturbed by reaction with locally emitted NO. As an index of oxidant, the sum of O3 and NO2 (Ox = O3 + NO2) is useful. In this study, a simultaneous and real-time analyzer of atmospheric Ox and NOx has been developed utilizing the dual NO2 detectors based on laser-induced fluorescence technique (LIF), and characterization of NOx emission was explored through the observations of Ox and NOx in the suburbs of Tokyo. The dual LIF detectors consisted of one laser head, two LIF cells, and one common vacuum pump. As the Ox monitor, the excess NO was added to the sample and O3 was converted to NO2, and then the sum of O3 and NO2 in the sample was quantified at the 1st LIF cell. As the NOx monitor, the excess O3 was added to the sample and NO was converted to NO2, and then the sum of NO and NO2 in the sample was quantified at the 2nd LIF cell. Both the ';Ox' and ';NOx' channels in the dual LIF analyzer were simultaneously monitoring Ox and NOx in the sample air, respectively. The temporal resolution of observed data was 1 s. Typical conversion efficiencies of O3 and NO to NO2 were more than 0.98. The lower detection limits were 0

  18. Estimation of NOx emissions from NO2 hotspots in polluted background using satellite observations

    Science.gov (United States)

    Liu, Fei; Beirle, Steffen; Zhang, Qiang; Wagner, Thomas

    2015-04-01

    Satellite observations have been widely used to study NOx emissions from power plants and cities, which are major NOx sources with large impacts on human health and climate. The quantification of NOx emissions from measured column densities of NO2 requires information on the NOx lifetime, which is typically gained from atmospheric chemistry models. But some recent studies determined the NOx lifetime from the satellite observations as well by analyzing the downwind plume evolution; however, this approach was so far only applied for strong isolated 'point sources' located in clean background, like Riyadh in Saudi Arabia. Here we present a modified method for the quantification of NOx emissions and corresponding atmospheric lifetimes based on OMI observations of NO2, together with ECMWF wind fields, but without further model input, for hot spots located in polluted background. We use the observed NO2 patterns under calm wind conditions as proxy for the spatial patterns of NOx emissions; by this approach, even complex source distributions can be treated realistically. From the change of the spatial patterns of NO2 at larger wind speeds (separately for different wind directions), the effective atmospheric lifetime is fitted. Emissions are derived from integrated NO2 columns above background by division by the corresponding lifetime. NOx lifetimes and emissions are estimated for 19 power plants and 50 cities across China and the US. The derived lifetimes are 3.3 ± 1.2 hours on average with extreme values of 0.9 to 7.7 hours. The resulting very short lifetimes for mountainous sites have been found to be uncertain due to the potentially inaccurate ECMWF wind data in mountainous regions. The derived NOx emissions show overall good agreement with bottom-up inventories.

  19. Most effective combustion technologies for reducing Nox emissions in aero gas turbines

    Directory of Open Access Journals (Sweden)

    F Ommi

    2016-09-01

    Full Text Available The growth in air transportation volume has important global environmental impacts associated with the potential for climate change. Jet aircraft emissions are deposited directly into the upper atmosphere and some of them have a greater warming effect than gases emitted closer to the surface. One of the key issues that is addressed in virtually every aero gas turbine application is emissions, particularly Nox emissions. There are different technologies for nitrogen oxide emission control in aircraft gas turbines. In this paper, we have briefly reviewed the technologies with the greatest potential to reduce Nox emissions in aero engines.

  20. Decreasing emissions of NOx relative to CO2 in East Asia inferred from satellite observations

    Science.gov (United States)

    Reuter, M.; Buchwitz, M.; Hilboll, A.; Richter, A.; Schneising, O.; Hilker, M.; Heymann, J.; Bovensmann, H.; Burrows, J. P.

    2014-11-01

    At present, global CO2 emission inventories are mainly based on bottom-up estimates that rely, for example, on reported fossil fuel consumptions and fuel types. The associated uncertainties propagate into the CO2-to-NOx emission ratios that are used in pollution prediction and monitoring, as well as into biospheric carbon fluxes derived by inverse models. Here we analyse simultaneous and co-located satellite retrievals from SCIAMACHY (ref. ; SCanning Imaging Absorption SpectroMeter for Atmospheric CHartographY) of the column-average dry-air mole fraction of CO2 (refs , ) and NO2 (refs , , ) for the years 2003-2011 to provide a top-down estimate of trends in emissions and in the ratio between CO2 and NOx emissions. Our analysis shows that the CO2-to-NOx emission ratio has increased by 4.2 +/- 1.7% yr-1 in East Asia. In this region, we find a large positive trend of CO2 emissions (9.8 +/- 1.7% yr-1), which we largely attribute to the growing Chinese economy. This trend exceeds the positive trend of NOx emissions (5.8 +/- 0.9% yr-1). Our findings suggest that the recently installed and renewed technology in East Asia, such as power plants, transportation and so on, is cleaner in terms of NOx emissions than the old infrastructure, and roughly matches relative emission levels in North America and Europe.

  1. NOx Emission Trading in a European Context: Discussion of the Economic, Legal, and Cultural Aspects

    Directory of Open Access Journals (Sweden)

    Chris P.A. Dekkers

    2001-01-01

    Full Text Available Emission trading is a new instrument in environmental policy. It is an alien notion in most European countries and it is often viewed with hesitation. The paper discusses the economic, legal, and perhaps more importantly, the cultural aspects to consider when one tries to explore the prospects for trading emissions of NOX and other substances in Europe. Issues to be addressed are the present legal framework in Europe in relation to the national emission ceilings on NOX and other substances on the basis of relevant EU directives and UNECE protocols. The paper will discuss the extent to which the legal framework within the EU imposes constraints on the design of a national emission trading scheme, and what options are available to fit emission trading into that legislative structure. The NOX emission trading programme developed in the Netherlands will be used to demonstrate the various aspects in a European context.

  2. NOx emission trends over Chinese cities estimated from OMI observations during 2005 to 2015

    Directory of Open Access Journals (Sweden)

    F. Liu

    2017-08-01

    Full Text Available Satellite nitrogen dioxide (NO2 observations have been widely used to evaluate emission changes. To determine trends in nitrogen oxides (NOx emission over China, we used a method independent of chemical transport models to quantify the NOx emissions from 48 cities and seven power plants over China, on the basis of Ozone Monitoring Instrument (OMI NO2 observations from 2005 to 2015. We found that NOx emissions over 48 Chinese cities increased by 52 % from 2005 to 2011 and decreased by 21 % from 2011 to 2015. The decrease since 2011 could be mainly attributed to emission control measures in power sector; while cities with different dominant emission sources (i.e., power, industrial, and transportation sectors showed variable emission decline timelines that corresponded to the schedules for emission control in different sectors. The time series of the derived NOx emissions was consistent with the bottom-up emission inventories for all power plants (r = 0. 8 on average, but not for some cities (r = 0. 4 on average. The lack of consistency observed for cities was most probably due to the high uncertainty of bottom-up urban emissions used in this study, which were derived from downscaling the regional-based emission data to city level by using spatial distribution proxies.

  3. NOx emission trends over Chinese cities estimated from OMI observations during 2005 to 2015

    Science.gov (United States)

    Liu, Fei; Beirle, Steffen; Zhang, Qiang; van der A, Ronald J.; Zheng, Bo; Tong, Dan; He, Kebin

    2017-08-01

    Satellite nitrogen dioxide (NO2) observations have been widely used to evaluate emission changes. To determine trends in nitrogen oxides (NOx) emission over China, we used a method independent of chemical transport models to quantify the NOx emissions from 48 cities and seven power plants over China, on the basis of Ozone Monitoring Instrument (OMI) NO2 observations from 2005 to 2015. We found that NOx emissions over 48 Chinese cities increased by 52 % from 2005 to 2011 and decreased by 21 % from 2011 to 2015. The decrease since 2011 could be mainly attributed to emission control measures in power sector; while cities with different dominant emission sources (i.e., power, industrial, and transportation sectors) showed variable emission decline timelines that corresponded to the schedules for emission control in different sectors. The time series of the derived NOx emissions was consistent with the bottom-up emission inventories for all power plants (r = 0. 8 on average), but not for some cities (r = 0. 4 on average). The lack of consistency observed for cities was most probably due to the high uncertainty of bottom-up urban emissions used in this study, which were derived from downscaling the regional-based emission data to city level by using spatial distribution proxies.

  4. Evaluating NOx emission inventories for regulatory air quality modeling using satellite and air quality model data

    Science.gov (United States)

    Kemball-Cook, Susan; Yarwood, Greg; Johnson, Jeremiah; Dornblaser, Bright; Estes, Mark

    2015-09-01

    The purpose of this study was to assess the accuracy of NOx emissions in the Texas Commission on Environmental Quality's (TCEQ) State Implementation Plan (SIP) modeling inventories of the southeastern U.S. We used retrieved satellite tropospheric NO2 columns from the Ozone Monitoring Instrument (OMI) together with NO2 columns from the Comprehensive Air Quality Model with Extensions (CAMx) to make top-down NOx emissions estimates using the mass balance method. Two different top-down NOx emissions estimates were developed using the KNMI DOMINO v2.0 and NASA SP2 retrievals of OMI NO2 columns. Differences in the top-down NOx emissions estimates made with these two operational products derived from the same OMI radiance data were sufficiently large that they could not be used to constrain the TCEQ NOx emissions in the southeast. The fact that the two available operational NO2 column retrievals give such different top-down NOx emissions results is important because these retrievals are increasingly being used to diagnose air quality problems and to inform efforts to solve them. These results reflect the fact that NO2 column retrievals are a blend of measurements and modeled data and should be used with caution in analyses that will inform policy development. This study illustrates both benefits and challenges of using satellite NO2 data for air quality management applications. Comparison with OMI NO2 columns pointed the way toward improvements in the CAMx simulation of the upper troposphere, but further refinement of both regional air quality models and the NO2 column retrievals is needed before the mass balance and other emission inversion methods can be used to successfully constrain NOx emission inventories used in U.S. regulatory modeling.

  5. A smart and robust NOx emission evaluation tool for the environmental screening of heavy-duty vehicles

    NARCIS (Netherlands)

    Vermeulen, R.J.; Ligterink, N.E.; Vonk, W.A.; Baarbe, H.L.

    2012-01-01

    At the request of the Dutch Ministry of Infrastructure and Environment a smart measurement system was developed to judge the real world NOx emission of heavy-duty vehicles. The measurement system uses a NOx - O2 sensor for the measurement of the tail pipe concentration of NOx and to estimate the

  6. The present-day and future impact of NOx emissions from subsonic aircraft on the atmosphere in relation to the impact of NOx surface sources

    Directory of Open Access Journals (Sweden)

    G. J. M. Velders

    Full Text Available The effect of present-day and future NOx emissions from aircraft on the NOx and ozone concentrations in the atmosphere and the corresponding radiative forcing were studied using a three-dimensional chemistry transport model (CTM and a radiative model. The effects of the aircraft emissions were compared with the effects of the three most important anthropogenic NOx surface sources: road traffic, electricity generation and industrial combustion. From the model results, NOx emissions from aircraft are seen to cause an increase in the NOx and ozone concentrations in the upper troposphere and lower stratosphere, and a positive radiative forcing. For the reference year 1990, the aircraft emissions result in an increase in the NOx concentration at 250 hPa of about 20 ppt in January and 50 ppt in July over the eastern USA, the North Atlantic Flight Corridor and Western Europe, corresponding to a relative increase of about 50%. The maximum increase in the ozone concentrations due to the aircraft emissions is about 3-4 ppb in July over the northern mid-latitudes, corresponding to a relative increase of about 3-4%. The aircraft-induced ozone changes cause a global average radiative forcing of 0.025 W/m2 in July. According to the ANCAT projection for the year 2015, the aircraft NOx emissions in that year will be 90% higher than in the year 1990. As a consequence of this, the calculated NOx perturbation by aircraft emissions increases by about 90% between 1990 and 2015, and the ozone perturbation by about 50-70%. The global average radiative forcing due to the aircraft-induced ozone changes increases by about 50% between 1990 and 2015. In the year 2015, the effects of the aircraft emissions on the ozone burden and radiative forcing are clearly larger than the individual effects of the NOx surface sources. Taking chemical conversion in the aircraft plume into account in the CTM explicitly, by means of modified aircraft NOx emissions, a significant reduction

  7. The present-day and future impact of NOx emissions from subsonic aircraft on the atmosphere in relation to the impact of NOx surface sources

    Directory of Open Access Journals (Sweden)

    P. J. M. Valks

    1999-08-01

    Full Text Available The effect of present-day and future NOx emissions from aircraft on the NOx and ozone concentrations in the atmosphere and the corresponding radiative forcing were studied using a three-dimensional chemistry transport model (CTM and a radiative model. The effects of the aircraft emissions were compared with the effects of the three most important anthropogenic NOx surface sources: road traffic, electricity generation and industrial combustion. From the model results, NOx emissions from aircraft are seen to cause an increase in the NOx and ozone concentrations in the upper troposphere and lower stratosphere, and a positive radiative forcing. For the reference year 1990, the aircraft emissions result in an increase in the NOx concentration at 250 hPa of about 20 ppt in January and 50 ppt in July over the eastern USA, the North Atlantic Flight Corridor and Western Europe, corresponding to a relative increase of about 50%. The maximum increase in the ozone concentrations due to the aircraft emissions is about 3-4 ppb in July over the northern mid-latitudes, corresponding to a relative increase of about 3-4%. The aircraft-induced ozone changes cause a global average radiative forcing of 0.025 W/m2 in July. According to the ANCAT projection for the year 2015, the aircraft NOx emissions in that year will be 90% higher than in the year 1990. As a consequence of this, the calculated NOx perturbation by aircraft emissions increases by about 90% between 1990 and 2015, and the ozone perturbation by about 50-70%. The global average radiative forcing due to the aircraft-induced ozone changes increases by about 50% between 1990 and 2015. In the year 2015, the effects of the aircraft emissions on the ozone burden and radiative forcing are clearly larger than the individual effects of the NOx surface sources. Taking chemical conversion in the aircraft plume into account in the CTM explicitly, by means of modified aircraft NOx emissions, a significant reduction

  8. Influence of satellite-derived photolysis rates and NOx emissions on Texas ozone modeling

    Science.gov (United States)

    Tang, W.; Cohan, D. S.; Pour-Biazar, A.; Lamsal, L. N.; White, A. T.; Xiao, X.; Zhou, W.; Henderson, B. H.; Lash, B. F.

    2015-02-01

    Uncertain photolysis rates and emission inventory impair the accuracy of state-level ozone (O3) regulatory modeling. Past studies have separately used satellite-observed clouds to correct the model-predicted photolysis rates, or satellite-constrained top-down NOx emissions to identify and reduce uncertainties in bottom-up NOx emissions. However, the joint application of multiple satellite-derived model inputs to improve O3 state implementation plan (SIP) modeling has rarely been explored. In this study, Geostationary Operational Environmental Satellite (GOES) observations of clouds are applied to derive the photolysis rates, replacing those used in Texas SIP modeling. This changes modeled O3 concentrations by up to 80 ppb and improves O3 simulations by reducing modeled normalized mean bias (NMB) and normalized mean error (NME) by up to 0.1. A sector-based discrete Kalman filter (DKF) inversion approach is incorporated with the Comprehensive Air Quality Model with extensions (CAMx)-decoupled direct method (DDM) model to adjust Texas NOx emissions using a high-resolution Ozone Monitoring Instrument (OMI) NO2 product. The discrepancy between OMI and CAMx NO2 vertical column densities (VCDs) is further reduced by increasing modeled NOx lifetime and adding an artificial amount of NO2 in the upper troposphere. The region-based DKF inversion suggests increasing NOx emissions by 10-50% in most regions, deteriorating the model performance in predicting ground NO2 and O3, while the sector-based DKF inversion tends to scale down area and nonroad NOx emissions by 50%, leading to a 2-5 ppb decrease in ground 8 h O3 predictions. Model performance in simulating ground NO2 and O3 are improved using sector-based inversion-constrained NOx emissions, with 0.25 and 0.04 reductions in NMBs and 0.13 and 0.04 reductions in NMEs, respectively. Using both GOES-derived photolysis rates and OMI-constrained NOx emissions together reduces modeled NMB and NME by 0.05, increases the model

  9. Reducing NOx emissions from a biodiesel-fueled engine by use of low-temperature combustion.

    Science.gov (United States)

    Fang, Tiegang; Lin, Yuan-Chung; Foong, Tien Mun; Lee, Chia-Fon

    2008-12-01

    Biodiesel is popularly discussed in many countries due to increased environmental awareness and the limited supply of petroleum. One of the main factors impacting general replacement of diesel by biodiesel is NOx (nitrogen oxides) emissions. Previous studies have shown higher NOx emissions relative to petroleum diesel in traditional direct-injection (DI) diesel engines. In this study, effects of injection timing and different biodiesel blends are studied for low load [2 bar IMEP (indicated mean effective pressure)] conditions. The results show that maximum heat release rate can be reduced by retarding fuel injection. Ignition and peak heat release rate are both delayed for fuels containing more biodiesel. Retarding the injection to post-TDC (top dead center) lowers the peak heat release and flattens the heat release curve. It is observed that low-temperature combustion effectively reduces NOx emissions because less thermal NOx is formed. Although biodiesel combustion produces more NOx for both conventional and late-injection strategies, with the latter leading to a low-temperature combustion mode, the levels of NOx of B20 (20 vol % soy biodiesel and 80 vol % European low-sulfur diesel), B50, and B100 all with post-TDC injection are 68.1%, 66.7%, and 64.4%, respectively, lower than pure European low-sulfur diesel in the conventional injection scenario.

  10. On the Effects of NOx Emission Control and Drought on an Ozone-Polluted Ecosystem

    Science.gov (United States)

    Pusede, S.; Geddes, J.; Buysse, C. E.; Esperanza, A.; Najacht, E.; Anderson, J. F.; Bailey, C. B.; Munyan, J.

    2017-12-01

    Regulatory emission controls are typically designed to reduce ozone when ozone is highest. However, high ozone concentrations are often asynchronous with periods of the greatest ozone harm to plants and ecosystems, particularly during drought. Because ozone production chemistry is nonlinear, emissions reductions designed to be effective in polluted cities may have a range of effects on downwind ecosystems. Here, we investigate the influence of regional NOx emission controls on ozone pollution in Sequoia National Park (SNP). First, we show that steep declines in NOx throughout the region have had smaller impacts in SNP than in cities upwind, and that these reductions have been least effective at times of day and year when plants are most sensitive to ozone. Second, in recent years (2012-2015), California experienced the worst drought in recorded history. We present observational evidence of the ozone response in SNP to drought conditions, finding that the drought altered the chemical sensitivity of local ozone production to NOx emissions and, hence, the effectiveness of NOx emission controls. We show that drought impacts on the ozone sensitivity to NOx have persisted at least two years since the drought ended.

  11. Modelling the spatial distribution of SO2 and NO(x) emissions in Ireland

    NARCIS (Netherlands)

    Kluizenaar, Y.de; Aherne, J.; Farrell, E.P.

    2001-01-01

    The spatial distributions of sulphur dioxide (SO2) and nitrogen oxides (NO(x)) emissions are essential inputs to models of atmospheric transport and deposition. Information of this type is required for international negotiations on emission reduction through the critical load approach.

  12. Field test of available methods to measure remotely SOx and NOx emissions from ships

    NARCIS (Netherlands)

    Balzani Lööv, J.M.; Alfoldy, B.; Gast, L.F.L.; Hjorth, J.; Lagler, F.; Mellqvist, J.; Beecken, J.; Berg, N.; Duyzer, J.; Westrate, H.; Swart, D.P.J.; Berkhout, A.J.C.; Jalkanen, J.P.; Prata, A.J.; Van Der Hoff, G.R.; Borowiak, A.

    2014-01-01

    Methods for the determination of ship fuel sulphur content and NOx emission factors based on remote measurements have been compared in the harbour of Rotterdam and compared to direct stack emission measurements on the ferry Stena Hollandica. The methods were selected based on a review of the

  13. Differences in satellite-derived NOx emission factors between Eurasian and North American boreal forest fires

    Science.gov (United States)

    Schreier, S. F.; Richter, A.; Schepaschenko, D.; Shvidenko, A.; Hilboll, A.; Burrows, J. P.

    2015-11-01

    Current fire emission inventories apply universal emission factors (EFs) for the calculation of NOx emissions over large biomes such as boreal forest. However, recent satellite-based studies over tropical and subtropical regions have indicated spatio-temporal variations in EFs within specific biomes. In this study, satellite measurements of tropospheric NO2 vertical columns (TVC NO2) from the GOME-2 instrument and fire radiative power (FRP) from MODIS are used for the estimation of fire emission rates (FERs) of NOx over Eurasian and North American boreal forests. The retrieval of TVC NO2 is based on a stratospheric correction using simulated stratospheric NO2 instead of applying the reference sector method, which was used in a previous study. The model approach is more suitable for boreal latitudes. TVC NO2 and FRP are spatially aggregated to a 1° × 1° horizontal resolution and temporally averaged to monthly values. The conversion of the satellite-derived tropospheric NO2 columns into production rates of NOx from fire (Pf) is based on the NO2/NOx ratio as obtained from the MACC reanalysis data set and an assumed lifetime of NOx. A global land cover map is used to define boreal forests across these two regions in order to evaluate the FERs of NOx for this biome. The FERs of NOx, which are derived from the gradients of the linear relationship between Pf and FRP, are more than 30% lower for North American than for Eurasian boreal forest fires. We speculate that these discrepancies are mainly related to the variable nitrogen content in plant tissues, which is higher in deciduous forests dominating large parts in Eurasia. In order to compare the obtained values with EFs found in the literature, the FERs are converted into EFs. The satellite-based EFs of NOx are estimated at 0.83 and 0.61 g kg-1 for Eurasian and North American boreal forests, respectively, which is in good agreement with the value found in a recent emission factor compilation. However, recent fire

  14. Importance of soil NO emissions for the total atmospheric NOx budget of Saxony, Germany

    Science.gov (United States)

    Molina-Herrera, Saúl; Haas, Edwin; Grote, Rüdiger; Kiese, Ralf; Klatt, Steffen; Kraus, David; Kampffmeyer, Tatjana; Friedrich, Rainer; Andreae, Henning; Loubet, Benjamin; Ammann, Christof; Horváth, László; Larsen, Klaus; Gruening, Carsten; Frumau, Arnoud; Butterbach-Bahl, Klaus

    2017-03-01

    Soils are a significant source for the secondary greenhouse gas NO and assumed to be a significant source of tropospheric NOx in rural areas. Here we tested the LandscapeDNDC model for its capability to simulate magnitudes and dynamics of soil NO emissions for 22 sites differing in land use (arable, grassland and forest) and edaphic as well as climatic conditions. Overall, LandscapeDNDC simulated mean soil NO emissions agreed well with observations (r2 = 0.82). However, simulated day to day variations of NO did only agree weakly with high temporal resolution measurements, though agreement between simulations and measurements significantly increased if data were aggregated to weekly, monthly and seasonal time scales. The model reproduced NO emissions from high and low emitting sites, and responded to fertilization (mineral and organic) events with pulse emissions. After evaluation, we linked the LandscapeDNDC model to a GIS database holding spatially explicit data on climate, land use, soil and management to quantify the contribution of soil biogenic NO emissions to the total NOx budget for the State of Saxony, Germany. Our calculations show that soils of both agricultural and forest systems are significant sources and contribute to about 8% (uncertainty range: 6-13%) to the total annual tropospheric NOx budget for Saxony. However, the contributions of soil NO emission to total tropospheric NOx showed a high spatial variability and in some rural regions such as the Ore Mts., simulated soil NO emissions were by far more important than anthropogenic sources.

  15. Investigating the microbial community responsible for unusually high soil N2O and NOx emissions in the Colorado Desert

    Science.gov (United States)

    Eberwein, J. R.; Carey, C.; Aronson, E. L.; Jenerette, D.

    2016-12-01

    Although the importance of soil nitrogenous emissions are well accepted in terms of local and global ecological relevance, there remain considerable knowledge gaps concerning the mechanisms regulating production, particularly in arid systems. This study aimed to connect desert soil trace gas emissions of nitrous oxide (N2O) and nitrogen oxides (NOx) with compositional changes in the microbial community. We quantified real-time soil trace gas emissions at two sites in the Colorado Desert experiencing contrasting anthropogenic nitrogen (N) deposition loads (characterize the soil microbial community. N2O fluxes reached as high as 1200 ng N2O-N m-2 s-1, well above most published emissions, but returned to pre-wetting conditions within 12 hours. NOx emissions reached as high as 350 ng NOx-N m-2 s-1 and remained elevated past 24 hours post-wetting. Results from the 16S analysis indicate distinct differences in the microbial community composition between the high and low N deposition sites, with less than 50% of operational taxonomic units (OTUs) in common between sites. N addition had a significant effect on the soil microbial community at the low deposition site, but not at the high deposition site. Furthermore, significant shifts in the bacterial community occurred after wetting, with only one third of the community remaining constant between time points. These results suggest that gaseous N export, particularly N2O emission, is a greater form of nitrogen loss in this system than is currently assumed. Experimental N additions and anthropogenic N deposition show potential for shifting soil microbial community composition, with implications for soil N emissions. Furthermore, shifts in the microbial community can occur as quickly as 15 minutes post-wetting, representing a remarkable ability for soil microorganisms to recover from extreme water stress. As aridlands cover approximately one third of the Earth's land surface, understanding the mechanisms that contribute to

  16. Experimental Assessment of NOx Emissions from 73 Euro 6 Diesel Passenger Cars.

    Science.gov (United States)

    Yang, Liuhanzi; Franco, Vicente; Mock, Peter; Kolke, Reinhard; Zhang, Shaojun; Wu, Ye; German, John

    2015-12-15

    Controlling nitrogen oxides (NOx) emissions from diesel passenger cars during real-world driving is one of the major technical challenges facing diesel auto manufacturers. Three main technologies are available for this purpose: exhaust gas recirculation (EGR), lean-burn NOx traps (LNT), and selective catalytic reduction (SCR). Seventy-three Euro 6 diesel passenger cars (8 EGR only, 40 LNT, and 25 SCR) were tested on a chassis dynamometer over both the European type-approval cycle (NEDC, cold engine start) and the more realistic Worldwide harmonized light-duty test cycle (WLTC version 2.0, hot start) between 2012 and 2015. Most vehicles met the legislative limit of 0.08 g/km of NOx over NEDC (average emission factors by technology: EGR-only 0.07 g/km, LNT 0.04 g/km, and SCR 0.05 g/km), but the average emission factors rose dramatically over WLTC (EGR-only 0.17 g/km, LNT 0.21 g/km, and SCR 0.13 g/km). Five LNT-equipped vehicles exhibited very poor performance over the WLTC, emitting 7-15 times the regulated limit. These results illustrate how diesel NOx emissions are not properly controlled under the current, NEDC-based homologation framework. The upcoming real-driving emissions (RDE) regulation, which mandates an additional on-road emissions test for EU type approvals, could be a step in the right direction to address this problem.

  17. Impacts and mitigation of excess diesel-related NOx emissions in 11 major vehicle markets

    Science.gov (United States)

    Anenberg, Susan C.; Miller, Joshua; Minjares, Ray; Du, Li; Henze, Daven K.; Lacey, Forrest; Malley, Christopher S.; Emberson, Lisa; Franco, Vicente; Klimont, Zbigniew; Heyes, Chris

    2017-05-01

    Vehicle emissions contribute to fine particulate matter (PM2.5) and tropospheric ozone air pollution, affecting human health, crop yields and climate worldwide. On-road diesel vehicles produce approximately 20 per cent of global anthropogenic emissions of nitrogen oxides (NOx), which are key PM2.5 and ozone precursors. Regulated NOx emission limits in leading markets have been progressively tightened, but current diesel vehicles emit far more NOx under real-world operating conditions than during laboratory certification testing. Here we show that across 11 markets, representing approximately 80 per cent of global diesel vehicle sales, nearly one-third of on-road heavy-duty diesel vehicle emissions and over half of on-road light-duty diesel vehicle emissions are in excess of certification limits. These excess emissions (totalling 4.6 million tons) are associated with about 38,000 PM2.5- and ozone-related premature deaths globally in 2015, including about 10 per cent of all ozone-related premature deaths in the 28 European Union member states. Heavy-duty vehicles are the dominant contributor to excess diesel NOx emissions and associated health impacts in almost all regions. Adopting and enforcing next-generation standards (more stringent than Euro 6/VI) could nearly eliminate real-world diesel-related NOx emissions in these markets, avoiding approximately 174,000 global PM2.5- and ozone-related premature deaths in 2040. Most of these benefits can be achieved by implementing Euro VI standards where they have not yet been adopted for heavy-duty vehicles.

  18. NOx lifetimes and emissions of cities and power plants in polluted background estimated by satellite observations

    Directory of Open Access Journals (Sweden)

    F. Liu

    2016-04-01

    Full Text Available We present a new method to quantify NOx emissions and corresponding atmospheric lifetimes from OMI NO2 observations together with ECMWF wind fields without further model input for sources located in a polluted background. NO2 patterns under calm wind conditions are used as proxy for the spatial patterns of NOx emissions, and the effective atmospheric NOx lifetime is determined from the change of spatial patterns measured at larger wind speeds. Emissions are subsequently derived from the NO2 mass above the background, integrated around the source of interest. Lifetimes and emissions are estimated for 17 power plants and 53 cities located in non-mountainous regions across China and the USA. The derived lifetimes for the ozone season (May–September are 3.8 ± 1.0 h (mean ± standard deviation with a range of 1.8 to 7.5 h. The derived NOx emissions show generally good agreement with bottom-up inventories for power plants and cities. Regional inventory shows better agreement with top-down estimates for Chinese cities compared to global inventory, most likely due to different downscaling approaches adopted in the two inventories.

  19. Reduce NOx Emissions by Adsorber-Reduction Catalyst on Lean Burn Gasoline Engine

    Directory of Open Access Journals (Sweden)

    Dongpeng Yue

    2013-09-01

    Full Text Available The effect of a new catalyst system composed of traditional three way catalyst converter and adsorber-reduction catalysis converter on the emission characteristics and BSFC (Breake Specific Fuel Consumption- BSFCof a lean burn gasoline engine operated were investigated in this paper under different schemes of catalyst converter arrangement and different speeds and loads. The results show that the position of Three Way Catalyst is before the NOx adsorber Catalyst was the best scheme of catalyst converter arrangement. Which has the highest converter efficiency of reduction NOx emission in lean burn gasoline engine. The effects of speed on the exhaust emission and BSFC were also related to the ratio of lean burn time to rich burn time and the absolute value of both time of the adsorber-reduction catalyst converter. The load of the engine was the main influential factor to the exhaust emission characteristics and BSFC of lean burn gasoline engine, and the more load of the engine was, the more NOx emission , the less NOx conversion rate (CNOx and the better BSFC were.

  20. Growth in NOx emissions from power plants in China: bottom-up estimates and satellite observations

    Directory of Open Access Journals (Sweden)

    Y. Lei

    2012-05-01

    Full Text Available Using OMI (Ozone Monitoring Instrument tropospheric NO2 columns and a nested-grid 3-D global chemical transport model (GEOS-Chem, we investigated the growth in NOx emissions from coal-fired power plants and their contributions to the growth in NO2 columns in 2005–2007 in China. We first developed a unit-based power plant NOx emission inventory for 2005–2007 to support this investigation. The total capacities of coal-fired power generation have increased by 48.8% in 2005–2007, with 92.2% of the total capacity additions coming from generator units with size ≥300 MW. The annual NOx emissions from coal-fired power plants were estimated to be 8.11 Tg NO2 for 2005 and 9.58 Tg NO2 for 2007, respectively. The modeled summer average tropospheric NO2 columns were highly correlated (R2 = 0.79–0.82 with OMI measurements over grids dominated by power plant emissions, with only 7–14% low bias, lending support to the high accuracy of the unit-based power plant NOx emission inventory. The ratios of OMI-derived annual and summer average tropospheric NO2 columns between 2007 and 2005 indicated that most of the grids with significant NO2 increases were related to power plant construction activities. OMI had the capability to trace the changes of NOx emissions from individual large power plants in cases where there is less interference from other NOx sources. Scenario runs from GEOS-Chem model suggested that the new power plants contributed 18.5% and 10% to the annual average NO2 columns in 2007 in Inner Mongolia and North China, respectively. The massive new power plant NOx emissions significantly changed the local NO2 profiles, especially in less polluted areas. A sensitivity study found that changes of NO2 shape factors due to including new power plant emissions increased the summer average OMI tropospheric NO2 columns by 3.8–17.2% for six selected locations, indicating that the updated emission information could help to improve the satellite

  1. Growth in NOx emissions from power plants in China: bottom-up estimates and satellite observations

    Science.gov (United States)

    Wang, S. W.; Zhang, Q.; Streets, D. G.; He, K. B.; Martin, R. V.; Lamsal, L. N.; Chen, D.; Lei, Y.; Lu, Z.

    2012-05-01

    Using OMI (Ozone Monitoring Instrument) tropospheric NO2 columns and a nested-grid 3-D global chemical transport model (GEOS-Chem), we investigated the growth in NOx emissions from coal-fired power plants and their contributions to the growth in NO2 columns in 2005-2007 in China. We first developed a unit-based power plant NOx emission inventory for 2005-2007 to support this investigation. The total capacities of coal-fired power generation have increased by 48.8% in 2005-2007, with 92.2% of the total capacity additions coming from generator units with size ≥300 MW. The annual NOx emissions from coal-fired power plants were estimated to be 8.11 Tg NO2 for 2005 and 9.58 Tg NO2 for 2007, respectively. The modeled summer average tropospheric NO2 columns were highly correlated (R2 = 0.79-0.82) with OMI measurements over grids dominated by power plant emissions, with only 7-14% low bias, lending support to the high accuracy of the unit-based power plant NOx emission inventory. The ratios of OMI-derived annual and summer average tropospheric NO2 columns between 2007 and 2005 indicated that most of the grids with significant NO2 increases were related to power plant construction activities. OMI had the capability to trace the changes of NOx emissions from individual large power plants in cases where there is less interference from other NOx sources. Scenario runs from GEOS-Chem model suggested that the new power plants contributed 18.5% and 10% to the annual average NO2 columns in 2007 in Inner Mongolia and North China, respectively. The massive new power plant NOx emissions significantly changed the local NO2 profiles, especially in less polluted areas. A sensitivity study found that changes of NO2 shape factors due to including new power plant emissions increased the summer average OMI tropospheric NO2 columns by 3.8-17.2% for six selected locations, indicating that the updated emission information could help to improve the satellite retrievals.

  2. Comparison of wintertime CO to NOx ratios to MOVES and MOBILE6.2 on-road emissions inventories

    Science.gov (United States)

    Wallace, H. W.; Jobson, B. T.; Erickson, M. H.; McCoskey, J. K.; VanReken, T. M.; Lamb, B. K.; Vaughan, J. K.; Hardy, R. J.; Cole, J. L.; Strachan, S. M.; Zhang, W.

    2012-12-01

    The CO-to-NOx molar emission ratios from the US EPA vehicle emissions models MOVES and MOBILE6.2 were compared to urban wintertime measurements of CO and NOx. Measurements of CO, NOx, and volatile organic compounds were made at a regional air monitoring site in Boise, Idaho for 2 months from December 2008 to January 2009. The site is impacted by roadway emissions from a nearby busy urban arterial roads and highway. The measured CO-to-NOx ratio for morning rush hour periods was 4.2 ± 0.6. The average CO-to-NOx ratio during weekdays between the hours of 08:00 and 18:00 when vehicle miles travelled were highest was 5.2 ± 0.5. For this time period, MOVES yields an average hourly CO-to-NOx ratio of 9.1 compared to 20.2 for MOBILE6.2. Off-network emissions are a significant fraction of the CO and NOx emissions in MOVES, accounting for 65% of total CO emissions, and significantly increase the CO-to-NOx molar ratio. Observed ratios were more similar to the average hourly running emissions for urban roads determined by MOVES to be 4.3.

  3. Study of the NOx emissions during 'fluidised bed' combustion of Bulgarian lignite

    International Nuclear Information System (INIS)

    Bonev, B.; Totev, T.; Stanoev, Vl.; Velkova, A.; Barzilova, S.

    2003-01-01

    Based on the conducted experiment for lignite from 'Maritsa Iztok' fluidized bed combustion, an analysis is done of the impact of different fuel parameters (diameter of coal particles; bed temperature; ash content of the coal particles, oxygen content of the fluidized agent ) on NOx emissions

  4. Projection of SO2, NOx, NMVOC, particulate matter and black carbon emissions - 2015-2030

    DEFF Research Database (Denmark)

    Nielsen, Ole-Kenneth; Plejdrup, Marlene Schmidt; Hjelgaard, Katja Hossy

    This report contains a description of models and background data for projection of SO2, NOX, NMVOC, PM2.5 and black carbon for Denmark. The emissions are projected to 2030 using basic scenarios together with the expected results of a few individual policy measures. Official Danish forecasts...

  5. Quantifying emissions of NH3 and NOx from Agricultural Sources and Biomass Burning using SOF

    Science.gov (United States)

    Kille, N.; Volkamer, R. M.; Dix, B. K.

    2017-12-01

    Column measurements of trace gas absorption along the direct solar beam present a powerful yet underused approach to quantify emission fluxes from area sources. The University of Colorado Solar Occultation Flux (CU SOF) instrument (Kille et al., 2017, AMT, doi:10.5194/amt-10-373-2017) features a solar tracker that is self-positioning for use from mobile platforms that are in motion (Baidar et al., 2016, AMT, doi: 10.5194/amt-9-963-2016). This enables the use from research aircraft, as well as the deployment under broken cloud conditions, while making efficient use of aircraft time. First airborne SOF measurements have been demonstrated recently, and we discuss applications to study emissions from biomass burning using aircraft, and to study primary emissions of ammonia and nitrogen oxides (= NO + NO2) from area sources such as concentrated animal feeding operations (CAFO). SOF detects gases in the open atmosphere (no inlets), does not require access to the source, and provides results in units that can be directly compared with emission inventories. The method of emission quantification is relatively straightforward. During FRAPPE (Front Range Air Pollution and Photochemistry Experiment) in Colorado in 2014, we measured emission fluxes of NH3, and NOx from CAFO, quantifying the emissions from 61400 of the 535766 cattle in Weld County, CO (11.4% of the cattle population). We find that NH3 emissions from dairy and cattle farms are similar after normalization by the number of cattle, i.e., we find emission factors, EF, of 11.8 ± 2.0 gNH3/h/head for the studied CAFOs; these EFs are at the upper end of reported values. Results are compared to daytime NEI emissions for case study days. Furthermore, biologically active soils are found to be a strong source of NOx. The NOx sources account for 1.2% of the N-flux (i.e., NH3), and can be competitive with other NOx sources in Weld, CO. The added NOx is particularly relevant in remote regions, where O3 formation and oxidative

  6. Low modeled ozone production suggests underestimation of precursor emissions (especially NOx) in Europe

    Science.gov (United States)

    Oikonomakis, Emmanouil; Aksoyoglu, Sebnem; Ciarelli, Giancarlo; Baltensperger, Urs; Prévôt, André Stephan Henry

    2018-02-01

    High surface ozone concentrations, which usually occur when photochemical ozone production takes place, pose a great risk to human health and vegetation. Air quality models are often used by policy makers as tools for the development of ozone mitigation strategies. However, the modeled ozone production is often not or not enough evaluated in many ozone modeling studies. The focus of this work is to evaluate the modeled ozone production in Europe indirectly, with the use of the ozone-temperature correlation for the summer of 2010 and to analyze its sensitivity to precursor emissions and meteorology by using the regional air quality model, the Comprehensive Air Quality Model with Extensions (CAMx). The results show that the model significantly underestimates the observed high afternoon surface ozone mixing ratios (≥ 60 ppb) by 10-20 ppb and overestimates the lower ones (emissions, four scenarios were tested: (i) increased volatile organic compound (VOC) emissions by a factor of 1.5 and 2 for the anthropogenic and biogenic VOC emissions, respectively, (ii) increased nitrogen oxide (NOx) emissions by a factor of 2, (iii) a combination of the first two scenarios and (iv) increased traffic-only NOx emissions by a factor of 4. For southern, eastern, and central (except the Benelux area) Europe, doubling NOx emissions seems to be the most efficient scenario to reduce the underestimation of the observed high ozone mixing ratios without significant degradation of the model performance for the lower ozone mixing ratios. The model performance for ozone-temperature correlation is also better when NOx emissions are doubled. In the Benelux area, however, the third scenario (where both NOx and VOC emissions are increased) leads to a better model performance. Although increasing only the traffic NOx emissions by a factor of 4 gave very similar results to the doubling of all NOx emissions, the first scenario is more consistent with the uncertainties reported by other studies than

  7. Low modeled ozone production suggests underestimation of precursor emissions (especially NOx in Europe

    Directory of Open Access Journals (Sweden)

    E. Oikonomakis

    2018-02-01

    Full Text Available High surface ozone concentrations, which usually occur when photochemical ozone production takes place, pose a great risk to human health and vegetation. Air quality models are often used by policy makers as tools for the development of ozone mitigation strategies. However, the modeled ozone production is often not or not enough evaluated in many ozone modeling studies. The focus of this work is to evaluate the modeled ozone production in Europe indirectly, with the use of the ozone–temperature correlation for the summer of 2010 and to analyze its sensitivity to precursor emissions and meteorology by using the regional air quality model, the Comprehensive Air Quality Model with Extensions (CAMx. The results show that the model significantly underestimates the observed high afternoon surface ozone mixing ratios (≥  60 ppb by 10–20 ppb and overestimates the lower ones (<  40 ppb by 5–15 ppb, resulting in a misleading good agreement with the observations for average ozone. The model also underestimates the ozone–temperature regression slope by about a factor of 2 for most of the measurement stations. To investigate the impact of emissions, four scenarios were tested: (i increased volatile organic compound (VOC emissions by a factor of 1.5 and 2 for the anthropogenic and biogenic VOC emissions, respectively, (ii increased nitrogen oxide (NOx emissions by a factor of 2, (iii a combination of the first two scenarios and (iv increased traffic-only NOx emissions by a factor of 4. For southern, eastern, and central (except the Benelux area Europe, doubling NOx emissions seems to be the most efficient scenario to reduce the underestimation of the observed high ozone mixing ratios without significant degradation of the model performance for the lower ozone mixing ratios. The model performance for ozone–temperature correlation is also better when NOx emissions are doubled. In the Benelux area, however, the third scenario

  8. Application of an EGR system in a direct injection diesel engine to reduce NOx emissions

    Science.gov (United States)

    De Serio, D.; De Oliveira, A.; Sodré, J. R.

    2016-09-01

    This work presents the application of an exhaust gas recirculation (EGR) system in a direct injection diesel engine operating with diesel oil containing 7% biodiesel (B7). EGR rates of up to 10% were applied with the primary aim to reduce oxides of nitrogen (NOx) emissions. The experiments were conducted in a 44 kW diesel power generator to evaluate engine performance and emissions for different load settings. The use of EGR caused a peak pressure reduction during the combustion process and a decrease in thermal efficiency, mainly at high engine loads. A reduction of NOx emissions of up to 26% was achieved, though penalizing carbon monoxide (CO) and total hydrocarbons (THC) emissions.

  9. Evolution of NOx emissions in Europe with focus on road transport control measures

    Directory of Open Access Journals (Sweden)

    S. Reis

    2009-02-01

    Full Text Available European emission trends of nitrogen oxides since 1880 and up to present are presented here and are linked to the evolution of road transport emissions. Road transport has been the dominating source of NOx emissions since 1970, and contributes with 40% to the total emissions in 2005. Five trend regimes have been identified between 1880 and 2005. The first regime (1880–1950 is determined by a slow increase in fuel consumption all over Europe. The second regime (1950–1980 is characterized by a continued steep upward trend in liquid fuel use and by the introduction of the first regulations on road traffic emissions. Reduction in fuel consumption determines the emission trends in the third regime (1980–1990 that is also characterized by important differences between Eastern and Western Europe. Emissions from road traffic continue to grow in Western Europe in this period, and it is argued here that the reason for this continued NOx emission increase is related to early inefficient regulations for NOx in the transport sector. The fourth regime (1990–2000 involves a turning point for road traffic emissions, with a general decrease of emissions in Europe during that decade. It is in this period that we can identify the first emission reductions due to technological abatement in Western Europe. In the fifth regime (2000–2005, the economic recovery in Eastern Europe imposes increased emission from road traffic in this area. Western European emissions are on the other hand decoupled from the fuel consumption, and continue to decrease. The implementation of strict measures to control NOx emissions is demonstrated here to be a main reason for the continued Western European emission reductions. The results indicate that even though the effectiveness of European standards is hampered by a slow vehicle turnover, loopholes in the type-approval testing, and an increase in diesel consumption, the effect of such technical abatement measures is traceable

  10. Understanding Emissions in East Asia - The KORUS 2015 Emissions Inventory

    Science.gov (United States)

    Woo, J. H.; Kim, Y.; Park, R.; Choi, Y.; Simpson, I. J.; Emmons, L. K.; Streets, D. G.

    2017-12-01

    The air quality over Northeast Asia have been deteriorated for decades due to high population and energy use in the region. Despite of more stringent air pollution control policies by the governments, air quality over the region seems not been improved as much - even worse sometimes. The needs of more scientific understanding of inter-relationship among emissions, transport, chemistry over the region are much higher to effectively protect public health and ecosystems. Two aircraft filed campaigns targeting year 2016, MAPS-Seoul and KORUS-AQ, have been organized to study the air quality of over Korea and East Asia relating to chemical evolution, emission inventories, trans-boundary contribution, and satellite application. We developed a new East-Asia emissions inventory, named KORUS2015, based on NIER/KU-CREATE (Comprehensive Regional Emissions inventory for Atmospheric Transport Experiment), in support of the filed campaigns. For anthropogenic emissions, it has 54 fuel classes, 201 sub-sectors and 13 pollutants, including CO2, SO2, NOx, CO, NMVOC, NH3, PM10, and PM2.5. Since the KORUS2015 emissions framework was developed using the integrated climate and air quality assessment modeling framework (i.e. GAINS) and is fully connected with the comprehensive emission processing/modeling systems (i.e. SMOKE, KU-EPS, and MEGAN), it can be effectively used to support atmospheric field campaigns for science and policy. During the field campaigns, we are providing modeling emissions inventory to participating air quality models, such as CMAQ, WRF-Chem, CAMx, GEOS-Chem, MOZART, for forecasting and post-analysis modes. Based on initial assessment of those results, we are improving our emissions, such as VOC speciation, biogenic VOCs modeling. From the 2nditeration between emissions and modeling/measurement, further analysis results will be presented at the conference. Acknowledgements : This subject is supported by Korea Ministry of Environment as "Climate Change

  11. SELECTIVE CATALYTIC REDUCTION OF DIESEL ENGINE NOX EMISSIONS USING ETHANOL AS A REDUCTANT

    Energy Technology Data Exchange (ETDEWEB)

    (1)Kass, M; Thomas, J; Lewis, S; Storey, J; Domingo, N; Graves, R (2) Panov, A

    2003-08-24

    NOx emissions from a heavy-duty diesel engine were reduced by more than 90% and 80% utilizing a full-scale ethanol-SCR system for space velocities of 21000/h and 57000/h respectively. These results were achieved for catalyst temperatures between 360 and 400 C and for C1:NOx ratios of 4-6. The SCR process appears to rapidly convert ethanol to acetaldehyde, which subsequently slipped past the catalyst at appreciable levels at a space velocity of 57000/h. Ammonia and N2O were produced during conversion; the concentrations of each were higher for the low space velocity condition. However, the concentration of N2O did not exceed 10 ppm. In contrast to other catalyst technologies, NOx reduction appeared to be enhanced by initial catalyst aging, with the presumed mechanism being sulfate accumulation within the catalyst. A concept for utilizing ethanol (distilled from an E-diesel fuel) as the SCR reductant was demonstrated.

  12. Quantification of variability and uncertainty in lawn and garden equipment NOx and total hydrocarbon emission factors.

    Science.gov (United States)

    Frey, H Christopher; Bammi, Sachin

    2002-04-01

    Variability refers to real differences in emissions among multiple emission sources at any given time or over time for any individual emission source. Variability in emissions can be attributed to variation in fuel or feedstock composition, ambient temperature, design, maintenance, or operation. Uncertainty refers to lack of knowledge regarding the true value of emissions. Sources of uncertainty include small sample sizes, bias or imprecision in measurements, nonrepresentativeness, or lack of data. Quantitative methods for characterizing both variability and uncertainty are demonstrated and applied to case studies of emission factors for lawn and garden (L&G) equipment engines. Variability was quantified using empirical and parametric distributions. Bootstrap simulation was used to characterize confidence intervals for the fitted distributions. The 95% confidence intervals for the mean grams per brake horsepower/hour (g/hp-hr) emission factors for two-stroke engine total hydrocarbon (THC) and NOx emissions were from -30 to +41% and from -45 to +75%, respectively. The confidence intervals for four-stroke engines were from -33 to +46% for THCs and from -27 to +35% for NOx. These quantitative measures of uncertainty convey information regarding the quality of the emission factors and serve as a basis for calculation of uncertainty in emission inventories (EIs).

  13. Coupling of a NOx-trap and a DPF for emission reduction of a 6-cylinder HD engine; Verbindung eines NOx-Speicherkatalysators mit einem Diesel Partikel Filter zur Emissions-Reduzierung an einem 6 Zylinder Nfz Motor

    Energy Technology Data Exchange (ETDEWEB)

    Colliou, T.; Lavy, J.; Martin, B.; Dementhon, J.B. [IFP, Lyon (France); Pichon, G.; Chandes, K.; Pierron, L. [Renault Trucks., St Priest (France)

    2003-07-01

    To ensure overall optimization of engine performance (NOx, particulates, efficiency), the use of a NOx after-treatment system appears necessary to meet the European heavy duty vehicle EURO IV emissions standards. Among the identified means, the NOx-trap should offer efficiency comparable to that of reduction by urea, without having the same constraints. The trap works on the basis of the alternation of operating phases with a lean mixture during which NOx are stored and rich phases during which nitrates are destored and treated. The study has been performed on a RENAULT TRUCKS 6-cylinder 6,2 liters heavy-duty engine. A first investigation with a NOx-trap only has been carried out to evaluate and optimise the storage, destorage and reduction phases from the NOx conversion efficiency and fuel penalty trade-off. The equivalence ratio level, which affects the regeneration phase duration and efficiency, the fuel penalty and the temperature level of the NOx-trap have been shown as a key parameter. From the results obtained, high equivalence ratio regeneration (around 1.18) provides the best results. The necessity to run in rich condition, even for a short time, leads to an increase of particulate emission level and a DPF is therefore required. The different possible arrangements of the two after-treatment systems (NOx-trap and Catalysed DPF) have been evaluated in a second part of the study. The NOx-trap upstream the CDPF provides the best NOx / fuel penalty trade-off since it allows NOx slip reduction (reaction with the slipped reductants inside the CDPF) and do not disturb the rich pulses. For low NOx target, the requirement of NOx-trap regeneration frequency reduces the CRT effect efficiency. Thus, for these conditions, specific DPF regeneration strategies are required. The implementation of the CDPF upstream the NOx-trap can eliminate this drawback up to 1 g/kW.h NOx target without any CDPF loading process. Furthermore, the implementation of the CDPF upstream is

  14. Predictive NOx emission monitoring on board a passenger ferry

    International Nuclear Information System (INIS)

    Cooper, D.A.; Andreasson, K.

    1999-01-01

    NO x emissions from a medium speed diesel engine on board a servicing passenger ferry have been indirectly measured using a predictive emission monitoring system (PEMS) over a 1-yr period. Conventional NO x measurements were carried out with a continuous emission monitoring system (CEMS) at the start of the study to provide historical data for the empirical PEMS function. On three other occasions during the year the CEMS was also used to verify the PEMS and follow any changes in emission signature of the engine. The PEMS consisted of monitoring exhaust O 2 concentrations (in situ electrochemical probe), engine load, combustion air temperature and humidity, and barometric pressure. Practical experiences with the PEMS equipment were positive and measurement data were transferred to a land-based office by using a modem data communication system. The initial PEMS function (PEMS1) gave systematic differences of 1.1-6.9% of the calibration domain (0-1725 ppm) and a relative accuracy of 6.7% when compared with CEMS for whole journeys and varying load situations. Further improvements on the performance could be obtained by updating this function. The calculated yearly emission for a total engine running time of 4618 h was 316 t NO x ± 38 t and the average NO x emission corrected for ambient conditions 14.3 g kWh corr -1 . The exhaust profile of the engine in terms of NO x , CO and CO 2 emissions as determined by CEMS was similar for most of the year. Towards the end of the study period, a significantly lower NO x emission was detected which was probably caused by replacement of fuel injector nozzles. The study suggests that PEMS can be a viable option for continuous, long-term NO x measurements on board ships. (author)

  15. Radiative forcing from aircraft emissions of NOx: model calculations with CH4 surface flux boundary condition

    Directory of Open Access Journals (Sweden)

    Giovanni Pitari

    2017-12-01

    Full Text Available Two independent chemistry-transport models with troposphere-stratosphere coupling are used to quantify the different components of the radiative forcing (RF from aircraft emissions of NOx, i.e., the University of L'Aquila climate-chemistry model (ULAQ-CCM and the University of Oslo chemistry-transport model (Oslo-CTM3. The tropospheric NOx enhancement due to aircraft emissions produces a short-term O3 increase with a positive RF (+17.3 mW/m2 (as an average value of the two models. This is partly compensated by the CH4 decrease due to the OH enhancement (−9.4 mW/m2. The latter is a long-term response calculated using a surface CH4 flux boundary condition (FBC, with at least 50 years needed for the atmospheric CH4 to reach steady state. The radiative balance is also affected by the decreasing amount of CO2 produced at the end of the CH4 oxidation chain: an average CO2 accumulation change of −2.2 ppbv/yr is calculated on a 50 year time horizon (−1.6 mW/m2. The aviation perturbed amount of CH4 induces a long-term response of tropospheric O3 mostly due to less HO2 and CH3O2 being available for O3 production, compared with the reference case where a constant CH4 surface mixing ratio boundary condition is used (MBC (−3.9 mW/m2. The CH4 decrease induces a long-term response of stratospheric H2O (−1.4 mW/m2. The latter finally perturbs HOx and NOx in the stratosphere, with a more efficient NOx cycle for mid-stratospheric O3 depletion and a decreased O3 production from HO2+NO in the lower stratosphere. This produces a long-term stratospheric O3 loss, with a negative RF (−1.2 mW/m2, compared with the CH4 MBC case. Other contributions to the net NOx RF are those due to NO2 absorption of UV-A and aerosol perturbations (the latter calculated only in the ULAQ-CCM. These comprise: increasing sulfate due to more efficient oxidation of SO2, increasing inorganic and organic nitrates and the net aerosols indirect effect on warm clouds

  16. Reduction of NOx emissions in regenerative fossil fuel fired glass furnaces: a review of literature and experimental studies

    NARCIS (Netherlands)

    Beerkens, R.G.C.; Limpt, J.A.C. van

    2008-01-01

    The mechanism of nitrogen oxide (NOx) formation in combustion chambers of glass furnaces is briefly described. The most important parameters governing the NOx emissions of glass furnaces are discussed. Elimination or minimisation of conditions that cause the formation of nitrogen oxides in

  17. Low cost combustion tuning and fuel nozzles modification to reduce NOx emission in large coal-fired boilers

    Energy Technology Data Exchange (ETDEWEB)

    B. Chudnovsky; L. Levin; A. Talanker; E. Bar-Ziv; A. Vikhansky; A.F. Sarofim [Israel Electric Corporation (IEC), Haifa (Israel)

    2003-07-01

    This work focuses on low-cost combustion tuning to reduce NOx emission in coal-fired tangential boilers, testing the furnace in various operation modes. We have also experimented different coal nozzle types. The measurements were accompanied by computer simulations of the combustion process. We also used an on-line supervision system. The data obtained from 575 MW boilers show that with tuning and modified nozzles NOx was considerably reduced. The emission of NOx was reduced from 1200 to 570 mg/dNm{sup 3} at 6% O{sub 2} for South African coal at full load. At partial load NOx emission dropped from 1400 to 750-850 mg/dNm{sup 3} at 6% O{sub 2}. High volatile coal firing led to additional NOx reduction. A series of tests were performed with Colombian and Indonesian coals as well, dropping NOx emission to 400-450 mg/dNm{sup 3} at6% O{sub 2} at full load. Sootblowing optimization using the supervision system enabled us to further reduce NOx emission by approximately 10%. The boiler and unit performance was not influenced by any of the techniques used for NOx reduction. In such a manner, the results presented in this work clearly show that technological methods for reduction NOx are available and capable of obtaining the required NOx emission. We believe that the conclusions of the present study are general and may be applied to other utility boilers as well. 13 refs., 12 figs., 7 tabs.

  18. Factors Influencing Surface Emissions of CO and NOx From a Brazilian Savanna

    Science.gov (United States)

    Zepp, R. G.; Kisselle, K. W.; Burke, R. A.; Pinto, A. S.; Bustamante, M. M.

    2002-12-01

    Human activities in savannas such as biomass burning and land conversion influence soil and plant emissions of atmospheric carbon monoxide (CO) and NOx [nitric oxide (NO) plus nitrogen dioxide (NO2)]. Direct emissions of these gases from burning are a major global source. In addition, emissions of CO and NOX from soils and plant litter also provide a significant source of the gases. Here, we report field and laboratory investigations of the production of CO and NOx from soils and surface litter derived from two natural vegetation types in central Brazil, cerrado stricto sensu (20-50% canopy cover) and campo sujo (open scrubland). The field studies were conducted using opaque and transparent flux chambers to investigate the effects of illumination and heating of the land surface on the gas fluxes. These studies showed that both NOx and CO fluxes were elevated in the transparent chambers. The largest increases in NOx and CO fluxes were observed from recently burned surfaces, indicating that photochemical or temperature-sensitive precursors of the gases were produced in the surface residue by fire. Laboratory studies of the thermal production of CO from plant litter were species specific with activation energies ranging from 72 to 100 kJ mol-1. Activation energies for deciduous plant litter from the Brazilian sites were higher than those previously reported for African savanna grass litter. Other laboratory studies using simulated solar radiation demonstrated that removal of UV radiation by light filters strongly reduced CO fluxes, indicating that the observed enhancement of CO production under illumination was primarily due to photodegradation of the litter rather than enhanced thermal production.

  19. Comparisons of MOVES Light-duty Gasoline NOx Emission Rates with Real-world Measurements

    Science.gov (United States)

    Choi, D.; Sonntag, D.; Warila, J.

    2017-12-01

    Recent studies have shown differences between air quality model estimates and monitored values for nitrogen oxides. Several studies have suggested that the discrepancy between monitored and modeled values is due to an overestimation of NOx from mobile sources in EPA's emission inventory, particularly for light-duty gasoline vehicles. EPA's MOtor Vehicle Emission Simulator (MOVES) is an emission modeling system that estimates emissions for cars, trucks and other mobile sources at the national, county, and project level for criteria pollutants, greenhouse gases, and air toxics. Studies that directly measure vehicle emissions provide useful data for evaluating MOVES when the measurement conditions are properly accounted for in modeling. In this presentation, we show comparisons of MOVES2014 to thousands of real-world NOx emissions measurements from individual light-duty gasoline vehicles. The comparison studies include in-use vehicle emissions tests conducted on chassis dynamometer tests in support of Denver, Colorado's Vehicle Inspection & Maintenance Program and remote sensing data collected using road-side instruments in multiple locations and calendar years in the United States. In addition, we conduct comparisons of MOVES predictions to fleet-wide emissions measured from tunnels. We also present details on the methodology used to conduct the MOVES model runs in comparing to the independent data.

  20. Experimental Study on Relationship between NOx Emission and Fuel Consumption of a Diesel Engine

    Science.gov (United States)

    Ning, Ping; Liu, Chunjiang; Feng, Zhiqiang; Xia, Yijiang

    2018-01-01

    For YC6112 diesel engine assembled Delphl model single fuel pump electric controlled, in the premise of not changing its overall unit structure parameters of other systems, three different types of camshaft for single pumps, two kinds of fuel injectors, two types of superchargers and some phase shifting angle of different camshafts were chosen to match with the engine precisely, the experiments under thirteen kinds of working conditions for the engine with different matching were carried out, the change regulation between NOX emission and fuel consumption for the engine with different kinds of configurations was analyzed. The experiment results show the NOX emission and fuel consumption can be reduced greatly by configuring proper camshaft, fuel injectors and superchargers with YC6112 diesel engine.

  1. Reduction of NOx emissions when burning low heating value gas

    International Nuclear Information System (INIS)

    Gustafsson, R.; Oskarsson, J.; Waldheim, L.

    1993-09-01

    On the gasification of nitrogen-rich fuel the nitrogen from the fuel goes into the gas phase in the form of ammonia and hydrogen cyanide and also nitrogen containing tars. When the gas is combusted the nitrogen compounds are oxidized to a great extent to NO x and, therefore, high NO x emissions can be found on the combustion of low heating value gas produced from energy forest wood chips as is also the case with direct combustion of nitrogen rich fuels. An experimental study has been carried out where the important parameters for designing a combustion chamber for low heating value gases have been studied in order to obtain maximum reduction of NO x emissions. The effect of tar cracking using dolomite on these emissions and the effect of parameters such as the addition of steam has also been tested. The tests were carried out with energy forest wood chips with 0.3% nitrogen. The gasification was carried out in a pyrolysis reactor, operated to yield a low heating value gas, and which was coupled to a simplified gas turbine combustion chamber at atmospheric pressure. The results show that the main part of the nitrogen in the fuel is found as ammonia in the low heating value gas. With this type of gasification the conversion of fuel nitrogen to ammonia in the gas is equivalent to 500-600 mg/MJ, calculated as NO 2 . Only very low amounts of hydrogen cyanide have been noted and no nitrogen containing tar components have been found. No apparent effect of steam additions has been noted. On the other hand the distribution of air in the combustion chamber and residence time during the under stoichiometric conditions are of great importance for the NO x reduction. Depending on the air distribution the emissions of NO 2 varied between 100 and 250 mg/MJ, calculated as NO 2 . 23 refs, 11 figs, 2 tabs

  2. Emissions of CO2, CO, NOx, HC, PM, HFC-134a, N2O and CH4 from the global light duty vehicle fleet

    Directory of Open Access Journals (Sweden)

    Timothy J. Wallington

    2008-04-01

    Full Text Available Vehicles emit carbon dioxide (CO2, carbon monoxide (CO, nitrogen oxides (NOx, hydrocarbons (HC, particulate matter (PM, hydrofluorocarbon 134a (HFC-134a, methane (CH4, and nitrous oxide (N2O. An understanding of these emissions is needed in discussions of climate change and local air pollution issues. To facilitate such discussions an overview of past, present, and likely future emissions from light duty vehicles is presented. Emission control technologies have reduced the emissions of CO, VOCs, PM, HFC-134a, CH4, and N2O from modern vehicles to very low levels.

  3. Influence of Nox Emissions on Central Valley Fog Frequency and Persistence

    Science.gov (United States)

    Gray, E.; Baldocchi, D. D.; Goldstein, A. H.

    2016-12-01

    From 1930-1970, California's Central Valley (CV) radiation fog significantly increased, with locations such as Fresno seeing an 83% growth in fog frequency. However, in the last 30 years, researchers identified a 50% reduction in fog days (Baldocchi and Waller, 2014). The dominant hypotheses suggest that the decline in fog can be explained by rising temperatures associated with climate change or urban heat island effect. This assertion fails to explain the significant increase in CV fog midcentury. Here we instead assert that changes in air pollution, rather than climate, better explain this upward-then-downward temporal trend. As unregulated emissions increased NOx concentration from 1930-1970, it directly contributed to the formation of ammonium nitrate, the CV's dominate wintertime aerosol, which size range and hygroscopicity make efficient cloud condensation nuclei (CCN). Upon emission mitigation, NOx concentration declined rapidly, therefore reducing the CCN available for fog formation. Using over 75 years of meteorological measurements, we developed a detailed CV fog climatology. Additionally, we compiled a record of surface CV NOx concentration from 1963-Present as an indicator of subsequent secondary aerosol formation. We used this data to analyze the spatial and temporal correlation between fog frequency and mechanistic drivers of fog formation, including temperature, dewpoint, precipitation, wind speed, and aerosol concentration. In addition to the upward-then-downward temporal trend, CV fog frequency exhibits a pronounced north-south gradient, with fog consistently more frequent and persistent in southern latitudes than northern. Unlike temperature and wind speed records, precipitation and dewpoint trends exhibit a similar north-south spatial pattern. However, only NOx concentration adheres to both the upward-then-downward temporal trend and the north-south spatial distribution. Thus, we conclude that fog trends in the CV best correlate both temporally

  4. Characteristics and mechanism of NOx emission of hydrogen fueled internal combustion engine

    OpenAIRE

    Hairong ZHU; Zewei GENG; Qinggang LIU; Peiying PENG

    2017-01-01

    In order to deeply study the NOx formation mechanism of hydrogen fueled internal combustion engine (HICE), a hydrogen fueled internal combustion engine CFD simulation model including three-dimensional gridding coupling detailed chemical reaction mechanism is built based on CONVERGE software, and the combustion and emission characteristics of hydrogen fueled internal combustion engine under different loads are researched. The simulation result is consistent with the experimental data. The simu...

  5. Application of High Resolution Air-Borne Remote Sensing Observations for Monitoring NOx Emissions

    Science.gov (United States)

    Souri, A.; Choi, Y.; Pan, S.; Curci, G.; Janz, S. J.; Kowalewski, M. G.; Liu, J.; Herman, J. R.; Weinheimer, A. J.

    2017-12-01

    Nitrogen oxides (NOx=NO+NO2) are one of the air pollutants, responsible for the formation of tropospheric ozone, acid rain and particulate nitrate. The anthropogenic NOx emissions are commonly estimated based on bottom-up inventories which are complicated by many potential sources of error. One way to improve the emission inventories is to use relevant observations to constrain them. Fortunately, Nitrogen dioxide (NO2) is one of the most successful detected species from remote sensing. Although many studies have shown the capability of using space-borne remote sensing observations for monitoring emissions, the insufficient sample number and footprint of current measurements have introduced a burden to constrain emissions at fine scales. Promisingly, there are several air-borne sensors collected for NASA's campaigns providing high spatial resolution of NO2 columns. Here, we use the well-characterized NO2 columns from the Airborne Compact Atmospheric Mapper (ACAM) onboard NASA's B200 aircraft into a 1×1 km regional model to constrain anthropogenic NOx emissions in the Houston-Galveston-Brazoria area. Firstly, in order to incorporate the data, we convert the NO2 slant column densities to vertical ones using a joint of a radiative transfer model and the 1x1 km regional model constrained by P3-B aircraft measurements. After conducting an inverse modeling method using the Kalman filter, we find the ACAM observations are resourceful at mitigating the overprediction of model in reproducing NO2 on regular days. Moreover, the ACAM provides a unique opportunity to detect an anomaly in emissions leading to strong air quality degradation that is lacking in previous works. Our study provides convincing evidence that future geostationary satellites with high spatial and temporal resolutions will give us insights into uncertainties associated with the emissions at regional scales.

  6. NOx emissions from high swirl turbulent spray flames with highly oxygenated fuels

    KAUST Repository

    Bohon, Myles

    2013-01-01

    Combustion of fuels with fuel bound oxygen is of interest from both a practical and a fundamental viewpoint. While a great deal of work has been done studying the effect of oxygenated additives in diesel and gasoline engines, much less has been done examining combustion characteristics of fuels with extremely high mass fractions of fuel bound oxygen. This work presents an initial investigation into the very low NOx emissions resulting from the combustion of a model, high oxygen mass fraction fuel. Glycerol was chosen as a model fuel with a fuel bound oxygen mass fraction of 52%, and was compared with emissions measured from diesel combustion at similar conditions in a high swirl turbulent spray flame. This work has shown that high fuel bound oxygen mass fractions allow for combustion at low global equivalence ratios with comparable exhaust gas temperatures due to the significantly lower concentrations of diluting nitrogen. Despite similar exhaust gas temperatures, NOx emissions from glycerol combustion were up to an order of magnitude lower than those measured using diesel fuel. This is shown to be a result not of specific burner geometry, but rather is influenced by the presence of higher oxygen and lower nitrogen concentrations at the flame front inhibiting NOx production. © 2012 The Combustion Institute.

  7. Improved NOx emissions and combustion characteristics for a retrofitted down-fired 300-MWe utility boiler.

    Science.gov (United States)

    Li, Zhengqi; Ren, Feng; Chen, Zhichao; Liu, Guangkui; Xu, Zhenxing

    2010-05-15

    A new technique combining high boiler efficiency and low-NO(x) emissions was employed in a 300MWe down-fired boiler as an economical means to reduce NO(x) emissions in down-fired boilers burning low-volatile coals. Experiments were conducted on this boiler after the retrofit with measurements taken of gas temperature distributions along the primary air and coal mixture flows and in the furnace, furnace temperatures along the main axis and gas concentrations such as O(2), CO and NO(x) in the near-wall region. Data were compared with those obtained before the retrofit and verified that by applying the combined technique, gas temperature distributions in the furnace become more reasonable. Peak temperatures were lowered from the upper furnace to the lower furnace and flame stability was improved. Despite burning low-volatile coals, NO(x) emissions can be lowered by as much as 50% without increasing the levels of unburnt carbon in fly ash and reducing boiler thermal efficiency.

  8. Wintertime Overnight NOx Removal in a Southeastern United States Coal-fired Power Plant Plume: A Model for Understanding Winter NOx Processing and its Implications

    Science.gov (United States)

    Fibiger, Dorothy L.; McDuffie, Erin E.; Dubé, William P.; Aikin, Kenneth C.; Lopez-Hilfiker, Felipe D.; Lee, Ben H.; Green, Jaime R.; Fiddler, Marc N.; Holloway, John S.; Ebben, Carlena; Sparks, Tamara L.; Wooldridge, Paul; Weinheimer, Andrew J.; Montzka, Denise D.; Apel, Eric C.; Hornbrook, Rebecca S.; Hills, Alan J.; Blake, Nicola J.; DiGangi, Josh P.; Wolfe, Glenn M.; Bililign, Solomon; Cohen, Ronald C.; Thornton, Joel A.; Brown, Steven S.

    2018-01-01

    Nitric oxide (NO) is emitted in large quantities from coal-burning power plants. During the day, the plumes from these sources are efficiently mixed into the boundary layer, while at night, they may remain concentrated due to limited vertical mixing during which they undergo horizontal fanning. At night, the degree to which NO is converted to HNO3 and therefore unable to participate in next-day ozone (O3) formation depends on the mixing rate of the plume, the composition of power plant emissions, and the composition of the background atmosphere. In this study, we use observed plume intercepts from the Wintertime INvestigation of Transport, Emissions and Reactivity campaign to test sensitivity of overnight NOx removal to the N2O5 loss rate constant, plume mixing rate, background O3, and background levels of volatile organic compounds using a 2-D box model of power plant plume transport and chemistry. The factor that exerted the greatest control over NOx removal was the loss rate constant of N2O5. At the lowest observed N2O5 loss rate constant, no other combination of conditions converts more than 10% of the initial NOx to HNO3. The other factors did not influence NOx removal to the same degree.

  9. Top-down NOX Emissions of European Cities Derived from Modelled and Spaceborne Tropospheric NO2 Columns

    Science.gov (United States)

    Verstraeten, W. W.; Boersma, K. F.; Douros, J.; Williams, J. E.; Eskes, H.; Delcloo, A. W.

    2017-12-01

    High nitrogen oxides (NOX = NO + NO2) concentrations near the surface impact humans and ecosystems badly and play a key role in tropospheric chemistry. NO2 is an important precursor of tropospheric ozone (O3) which in turn affects the production of the hydroxyl radical controlling the chemical lifetime of key atmospheric pollutants and reactive greenhouse gases. Combustion from industrial, traffic and household activities in large and densely populated urban areas result in high NOX emissions. Accurate mapping of these emissions is essential but hard to do since reported emissions factors may differ from real-time emissions in order of magnitude. Modelled NO2 levels and lifetimes also have large associated uncertainties and overestimation in the chemical lifetime which may mask missing NOX chemistry in current chemistry transport models (CTM's). The simultaneously estimation of both the NO2 lifetime and as well as the concentrations by applying the Exponentially Modified Gaussian (EMG) method on tropospheric NO2 columns lines densities should improve the surface NOX emission estimates. Here we evaluate if the EMG methodology applied on the tropospheric NO2 columns simulated by the LOTOS-EUROS (Long Term Ozone Simulation-European Ozone Simulation) CTM can reproduce the NOX emissions used as model input. First we process both the modelled tropospheric NO2 columns for the period April-September 2013 for 21 selected European urban areas under windy conditions (averaged vertical wind speeds between surface and 500 m from ECMWF > 2 m s-1) as well as the accompanying OMI (Ozone Monitoring Instrument) data providing us with real-time observation-based estimates of midday NO2 columns. Then we compare the top-down derived surface NOX emissions with the 2011 MACC-III emission inventory, used in the CTM as input to simulate the NO2 columns. For cities where NOX emissions can be assumed as originating from one large source good agreement is found between the top-down derived

  10. Lightning NOx emissions over the USA constrained by TES ozone observations and the GEOS-Chem model

    Directory of Open Access Journals (Sweden)

    K. E. Pickering

    2010-01-01

    Full Text Available Improved estimates of NOx from lightning sources are required to understand tropospheric NOx and ozone distributions, the oxidising capacity of the troposphere and corresponding feedbacks between chemistry and climate change. In this paper, we report new satellite ozone observations from the Tropospheric Emission Spectrometer (TES instrument that can be used to test and constrain the parameterization of the lightning source of NOx in global models. Using the National Lightning Detection (NLDN and the Long Range Lightning Detection Network (LRLDN data as well as the HYPSLIT transport and dispersion model, we show that TES provides direct observations of ozone enhanced layers downwind of convective events over the USA in July 2006. We find that the GEOS-Chem global chemistry-transport model with a parameterization based on cloud top height, scaled regionally and monthly to OTD/LIS (Optical Transient Detector/Lightning Imaging Sensor climatology, captures the ozone enhancements seen by TES. We show that the model's ability to reproduce the location of the enhancements is due to the fact that this model reproduces the pattern of the convective events occurrence on a daily basis during the summer of 2006 over the USA, even though it does not well represent the relative distribution of lightning intensities. However, this model with a value of 6 Tg N/yr for the lightning source (i.e.: with a mean production of 260 moles NO/Flash over the USA in summer underestimates the intensities of the ozone enhancements seen by TES. By imposing a production of 520 moles NO/Flash for lightning occurring in midlatitudes, which better agrees with the values proposed by the most recent studies, we decrease the bias between TES and GEOS-Chem ozone over the USA in July 2006 by 40%. However, our conclusion on the strength of the lightning source of NOx is limited by the fact that the contribution from the stratosphere is underestimated in the GEOS-Chem simulations.

  11. Inversion of CO and NOx emissions using the adjoint of the IMAGES model

    Directory of Open Access Journals (Sweden)

    J.-F. Müller

    2005-01-01

    Full Text Available We use ground-based observations of CO mixing ratios and vertical column abundances together with tropospheric NO2 columns from the GOME satellite instrument as constraints for improving the global annual emission estimates of CO and NOx for the year 1997. The agreement between concentrations calculated by the global 3-dimensional CTM IMAGES and the observations is optimized using the adjoint modelling technique, which allows to invert for CO and NOx fluxes simultaneously, taking their chemical interactions into account. Our analysis quantifies a total of 39 flux parameters, comprising anthropogenic and biomass burning sources over large continental regions, soil and lightning emissions of NOx, biogenic emissions of CO and non-methane hydrocarbons, as well as the deposition velocities of both CO and NOx. Comparison between observed, prior and optimized CO mixing ratios at NOAA/CMDL sites shows that the inversion performs well at the northern mid- and high latitudes, and that it is less efficient in the Southern Hemisphere, as expected due to the scarsity of measurements over this part of the globe. The inversion, moreover, brings the model much closer to the measured NO2 columns over all regions. Sensitivity tests show that anthropogenic sources exhibit weak sensitivity to changes of the a priori errors associated to the bottom-up inventory, whereas biomass burning sources are subject to a strong variability. Our best estimate for the 1997 global top-down CO source amounts to 2760 Tg CO. Anthropogenic emissions increase by 28%, in agreement with previous inverse modelling studies, suggesting that the present bottom-up inventories underestimate the anthropogenic CO emissions in the Northern Hemisphere. The magnitude of the optimized NOx global source decreases by 14% with respect to the prior, and amounts to 42.1 Tg N, out of which 22.8 Tg N are due to anthropogenic sources. The NOx emissions increase over Tropical regions, whereas they decrease

  12. Air Pollution Inequality and Its Sources in SO2 and NOX Emissions among Chinese Provinces from 2006 to 2015

    Directory of Open Access Journals (Sweden)

    Mohaddeseh Azimi

    2018-01-01

    Full Text Available This paper investigates inequality in SO2 and NOX emissions, by observing their extraordinary levels and uneven distribution in China during the period of the 11th and 12th Five-Year Plans (FYPs, 2006–2015. This provincial and regional analysis utilizing the Theil index and Kaya factors help us to find the trajectory of inequality and its primary sources. Based on our analysis, we conclude the driving factors behind emissions inequalities are as follows. There are four economic factors of per capita SO2 emission: SO2 emission intensity of coal consumption, coal intensity of power generation, power intensity of GDP, and per capita GDP. Additionally, there are four urban development factors of per capita NOX emission: NOX emission intensity of gasoline consumption, proportion of gasoline vehicles, vehicle use in urban population, and urbanization rate. The SO2 emission results represent an increase of 6% in overall inequality where the inequality of power intensity of GDP is the main contributor. In terms of NOX emission, the 3% growth in total inequality is related to the high effect of NOX emission intensity of gasoline consumption. We also examine the effect of other factors affecting the trajectory of inequalities. To apply these results in practice, we compare the 11th and 12th FYPs and give some policy suggestions.

  13. NOx emissions and combustibility characteristics of coal blends

    Energy Technology Data Exchange (ETDEWEB)

    Rubiera, F.; Arenillas, A.; Arias, B.; Pis, J.J. [CSIC, Instituto Nacional del Carbon, Oviedo (Spain). Dept. of Energy and Environment

    2001-07-01

    In this work, a series of coals with different origin and rank were blended and several aspects of the resultant blends were studied. This included determination of the grindability of individual coals and blends by means of the Hardgrove Grindability Index (HGI), and temperature programmed combustion test, which were carried out in a thermogravimetric analyser (TG) coupled to a quadruple mass spectrometer (MS) for evolved gas analysis. Special attention was paid to the combustibility parameters and the NO emissions during blends combustion. It was found that while some coal blends present interaction between the individual coals, others do not. This behaviour was assumed to be due to the differences in coal structure and functional groups composition. 18 refs., 11 figs., 2 tabs.

  14. Present status and trends in SO2 and NOx emission control regulations in Europe

    International Nuclear Information System (INIS)

    Ellison, W.

    1987-01-01

    1983 West German legislation (GFAVO) calls for retrofitting by 1988 of FGD facilities of a minimum of 85% sulfur dioxide (SO2) removal efficiency, with stack emission no greater than 400 milligrams (mg) per normal cubic meter (Nm 3 ) of flue gas, for new and existing boilers greater than approximately 110 megawatts i.e. MW(e), size. As of 1986, more than 100 FGD systems with greater than 40,000 MW(e) aggregate capacity have been purchased in West Germany alone. 1983 West German legislation requires by 1993 the retrofit addition of approximately 400 more FGD installations aggregating approximately 25,000 MW(e) of capacity on boilers in the size range 35 to 110 MW(e). Stringent West German SO2 legislation in 1983 was followed in 1984 by enactment of very strict new nitrogen oxides (NOx) limits calling for emissions of no more than 200 mg NOx, measured as nitrogen dioxide, NO2, per Nm 3 , approximately 0.16 lb NO2 per million Btu heat input, for existing and new boilers greater than 110 MW(e), size. As of 1986 approximately 50 high-efficiency commercial systems aggregating more than 10,000 MW(e) capacity, most for retrofit addition, have been purchased in West Germany alone, and approximately 30,000 MW(e) of additional NOx removal capacity will be required to be retrofitted by deadlines during the period 1988 to 1990. For comparative purposes a brief description is given of regulations in North America for control of SO2 and NOx emissions from large coal-fired boilers

  15. Global Partitioning of NOx Sources Using Satellite Observations: Relative Roles of Fossil Fuel Combustion, Biomass Burning and Soil Emissions

    Science.gov (United States)

    Jaegle, Lyatt; Steinberger, Linda; Martin, Randall V.; Chance, Kelly

    2005-01-01

    This document contains the following abstract for the paper "Global partitioning of NOx sources using satellite observations: Relative roles of fossil fuel combustion, biomass burning and soil emissions." Satellite observations have been used to provide important new information about emissions of nitrogen oxides. Nitrogen oxides (NOx) are significant in atmospheric chemistry, having a role in ozone air pollution, acid deposition and climate change. We know that human activities have led to a three- to six-fold increase in NOx emissions since pre-industrial times, and that there are three main surface sources of NOx: fuel combustion, large-scale fires, and microbial soil processes. How each of these sources contributes to the total NOx emissions is subject to some doubt, however. The problem is that current NOx emission inventories rely on bottom-up approaches, compiling large quantities of statistical information from diverse sources such as fuel and land use, agricultural data, and estimates of burned areas. This results in inherently large uncertainties. To overcome this, Lyatt Jaegle and colleagues from the University of Washington, USA, used new satellite observations from the Global Ozone Monitoring Experiment (GOME) instrument. As the spatial and seasonal distribution of each of the sources of NOx can be clearly mapped from space, the team could provide independent topdown constraints on the individual strengths of NOx sources, and thus help resolve discrepancies in existing inventories. Jaegle's analysis of the satellite observations, presented at the recent Faraday Discussion on "Atmospheric Chemistry", shows that fuel combustion dominates emissions at northern mid-latitudes, while fires are a significant source in the Tropics. Additionally, she discovered a larger than expected role for soil emissions, especially over agricultural regions with heavy fertilizer use. Additional information is included in the original extended abstract.

  16. City-level variations in NOx emissions derived from hourly monitoring data in Chicago

    Science.gov (United States)

    de Foy, Benjamin

    2018-03-01

    Control on emissions of nitrogen oxides (NOx) in the United States of America have led to reductions in concentrations in urban areas by up to a factor of two in the last decade. The Air Quality System monitoring network provides surface measurements of concentrations at hourly resolution over multiple years, revealing variations at the annual, seasonal, day of week and diurnal time scales. A multiple linear regression model was used to estimate the temporal profiles in the NOx concentrations as well as the impact of meteorology, ozone concentrations, and boundary layer heights. The model is applied to data from 2005 to 2016 available at 6 sites in Chicago, Illinois. Results confirm the 50% decrease in NOx over the length of the time series. The weekend effect is found to be stronger in more commercial areas, with 32% reductions on Saturdays and 45% on Sundays and holidays; and weaker in more residential areas with 20% reductions on Saturdays and 30% reductions on Sundays. Weekday diurnal profiles follow a double hump with emission peaks during the morning and afternoon rush hours, but only a shallow drop during the middle day. Difference in profiles from the 6 sites suggest that there are different emission profiles within the urban area. Diurnal profiles on Saturdays have less variation throughout the day and more emissions in the evening. Sundays are very different from both weekdays and Saturdays with a gradual increase until the early evening. The results suggest that in addition to vehicle type and vehicle miles traveled, vehicle speed and congestion must be taken into account to correctly quantify morning rush hour emissions and the weekend effect.

  17. Public health impacts of excess NOx emissions from Volkswagen diesel passenger vehicles in Germany

    Science.gov (United States)

    Chossière, Guillaume P.; Malina, Robert; Ashok, Akshay; Dedoussi, Irene C.; Eastham, Sebastian D.; Speth, Raymond L.; Barrett, Steven R. H.

    2017-03-01

    In September 2015, the Volkswagen Group (VW) admitted the use of ‘defeat devices’ designed to lower emissions measured during VW vehicle testing for regulatory purposes. Globally, 11 million cars sold between 2008 and 2015 are affected, including about 2.6 million in Germany. On-road emissions tests have yielded mean on-road NOx emissions for these cars of 0.85 g km-1, over four times the applicable European limit of 0.18 g km-1. This study estimates the human health impacts and costs associated with excess emissions from VW cars driven in Germany. A distribution of on-road emissions factors is derived from existing measurements and combined with sales data and a vehicle fleet model to estimate total excess NOx emissions. These emissions are distributed on a 25 by 28 km grid covering Europe, using the German Federal Environmental Protection Agency’s (UBA) estimate of the spatial distribution of NOx emissions from passenger cars in Germany. We use the GEOS-Chem chemistry-transport model to predict the corresponding increase in population exposure to fine particulate matter and ozone in the European Union, Switzerland, and Norway, and a set of concentration-response functions to estimate mortality outcomes in terms of early deaths and of life-years lost. Integrated over the sales period (2008-2015), we estimate median mortality impacts from VW excess emissions in Germany to be 1200 premature deaths in Europe, corresponding to 13 000 life-years lost and 1.9 billion EUR in costs associated with life-years lost. Approximately 60% of mortality costs occur outside Germany. For the current fleet, we estimate that if on-road emissions for all affected VW vehicles in Germany are reduced to the applicable European emission standard by the end of 2017, this would avert 29 000 life-years lost and 4.1 billion 2015 EUR in health costs (median estimates) relative to a counterfactual case with no recall.

  18. Experimental investigation on NOx emission characteristics of a new solid fuel made from sewage sludge mixed with coal in combustion.

    Science.gov (United States)

    Zhai, Yunbo; Zhu, Lu; Chen, Hongmei; Xu, Bibo; Li, Caiting; Zeng, Guangming

    2015-02-01

    In this article, a new briquette fuel (SC), which was produced by the mixture of coal fines (25.9%), sewage sludge (60.6%), lignin (4.5%), tannic acid (4.5%) and elemental silicon (4.5%), was provided. Then, in a high temperature electric resistance tubular furnace, the total emissions of NO2 and NO, effects of combustion temperature, air flow rate and heating rate on NOx (NO, NO2) emissions of SC were studied during the combustion of SC; furthermore, effects of additives on hardness were also analysed, and the X-ray photoelectron spectroscopy was applied to investigate the reduced NOx emission mechanism. The research results showed that, compared with the characteristics of briquette fuel (SC0) produced only by the mixture of coal and sewage sludge (the ratio of coal to sewage sludge was the same as that of SC), the Meyer hardness of SC was 12.6% higher than that of SC0 and the emissions of NOx were 27.83% less than that of SC0 under the same combustion conditions. The NOx emissions of SC decreased with the adding of heating rate and increased with the rise of air flow rate. When the temperature was below 1000 °C, the emissions of NOx increased with the elevated temperature, however, further temperature extension will result in a decreasing in emissions of NOx. Furthermore, the X-ray photoelectron spectroscopy results proposed that the possible mechanism for the reduction of NOx emissions was nitrogen and silicon in SC to form the compounds of silicon and nitrogen at high temperatures. © The Author(s) 2015.

  19. The CO/NOx emissions of swirled, strongly pulsed jet diffusion flames

    KAUST Repository

    Liao, Ying-Hao

    2014-05-28

    The CO and NOx exhaust emissions of swirled, strongly pulsed, turbulent jet diffusion flames were studied experimentally in a coflow swirl combustor. Measurements of emissions were performed on the combustor centerline using standard emission analyzers combined with an aspirated sampling probe located downstream of the visible flame tip. The highest levels of CO emissions are generally found for compact, isolated flame puffs, which is consistent with the quenching due to rapid dilution with excess air. The imposition of swirl generally results in a decrease in CO levels by up to a factor of 2.5, suggesting more rapid and compete fuel/air mixing by imposing swirl in the coflow stream. The levels of NO emissions for most cases are generally below the steady-flame value. The NO levels become comparable to the steady-flame value for sufficiently short jet-off times. The swirled coflow air can, in some cases, increase the NO emissions due to a longer combustion residence time due to the flow recirculation within the swirl-induced recirculation zone. Scaling relations, when taking into account the impact of air dilution over an injection cycle on the flame length, reveal a strong correlation between the CO emissions and the global residence time. However, the NO emissions do not successfully correlate with the global residence time. For some specific cases, a compact flame with a simultaneous decrease in both CO and NO emissions compared to the steady flames was observed. © Copyright © Taylor & Francis Group, LLC.

  20. Emissions and transport of NOx over East Asia diagnosed by satellite and in-situ observations and chemical transport model results

    Science.gov (United States)

    Lee, H.; Kim, S.; Brioude, J.; Cooper, O. R.; Frost, G. J.; Trainer, M.; Kim, C.

    2012-12-01

    Nitrogen dioxide (NO2) columns observed from space have been useful in detecting the increase of NOx emissions over East Asia in accordance with rapid growth in its economy. In addition to emissions, transport can be an important factor to determine the observed satellite NO2 columns in this region. Satellite tropospheric NO2 columns showed maximum in winter and minimum in summer over the high emission areas in China, as lifetime of NO2 decreases with increase of sunlight. However, secondary peaks in the satellite NO2 columns were found in spring in both Korea and Japan, which may be influenced by transport of NOx within East Asia. Surface in-situ observations confirm the findings from the satellite measurements. The large-scale distribution of satellite NO2 columns over East Asia and the Pacific Ocean showed that the locations of NO2 column maxima coincided with wind convergence zones that change with seasons. In spring, the convergence zone is located over 30-40°N, leading to the most efficient transport of the emissions from southern China to downwind areas including Korea, Japan, and western coastal regions of the United States. We employed a Lagrangian particle dispersion model to identify the sources of the observed springtime maximum NO2. In order to understand chemical processing during the transport and quantify the roles of emissions and transport in local NOx budgets, we will also present the results from a regional chemical transport model.

  1. Eagle Ford Shale BTEX and NOx concentrations are dominated by oil and gas industry emissions

    Science.gov (United States)

    Schade, G. W.; Roest, G. S.

    2017-12-01

    US shale oil and gas exploration has been identified as a major source of greenhouse gases and non-methane hydrocarbon (NMHC) emissions to the atmosphere. Here, we present a detailed analysis of 2015 air quality data acquired by the Texas Commission on Environmental Quality (TCEQ) at an air quality monitoring station in Karnes County, TX, central to Texas' Eagle Ford shale area. Data include time series of hourly measured NMHCs, nitrogen oxides (NOx), and hydrogen sulfide (H2S) alongside meteorological measurements. The monitor was located in Karnes City, and thus affected by various anthropogenic emissions, including traffic and oil and gas exploration sources. Highest mixing ratios measured in 2015 included nearly 1 ppm ethane, 0.8 ppm propane, alongside 4 ppb benzene. A least-squares minimization non-negative matrix factorization (NMF) analysis, tested with prior data analyzed using standard PMF-2 software, showed six major emission sources: an evaporative and fugitive source, a flaring source, a traffic source, an oil field source, a diesel source, and an industrial manufacturing source, together accounting for more than 95% of data set variability, and interpreted using NMHC composition and meteorological data. Factor scores strongly suggest that NOx emissions are dominated by flaring and associated sources, such as diesel compressor engines, likely at midstream facilities, while traffic in this rural area is a minor NOx source. The results support, but exceed existing 2012 emission inventories estimating that local traffic emitted seven times fewer NOx than oil and gas exploration sources in the county. Sources of air toxics such as the BTEX compounds are also dominated by oil and gas exploration sources, but are more equally distributed between the associated factors. Benzene abundance is only 20-40% associated with traffic sources, and may thus be 2.5-5 times higher now than prior to the shale boom in this area. Although the monitor was located relatively

  2. Assessment and Mitigation of NOx emission within a street canyon and tunnel portal micro environment

    Science.gov (United States)

    Uhrner, Ulrich; Reifeltshammer, Rafael

    2017-04-01

    Substantial breeches of the NO2 annual mean have been recorded at an air quality station located in a busy road in a German city. The daily traffic volume is about 26 000 vehicles a day and the share of heavy duty vehicles is small due to a heavy traffic driving ban. Critical is that traffic from the 540 m long city tunnel bends into the road and that there are tall buildings located at both sides of the road. 9 additional measurements with passive samplers indicate that the air quality limit value is exceeded from the tunnel portal towards the next major intersection (approximately 500 m). The objective of this study is to compute emissions from open roads versus tunnel portal emissions and to analyse their effect upon local air quality within this complex urban micro environment. The aim of this project was to evaluate the impact of tunnel ventilation and traffic reductions measures. A base case was computed using sophisticated flow and dispersion modelling, accounting for the impact of buildings and the effect of the sunken road and tunnel jet. NOx to NO2 conversion was computed using a Romberg type approach and good results were obtained for NO2 annual means compared with measurements. The effect of tunnel emissions and emissions from open roads was analysed respectively. The NOx/NO2 concentration pattern revealed that the portal area is affected by the portal emissions about 60 m in driving direction. However, kerbside concentrations are dominated only within 30 m in driving direction. At the air quality station at 150 m distance from the portal, 75 % of the NOx concentrations can be attributed to open roads and the rest is mainly attributable to urban background. A zero portal emission scenario resulted in significant improvement within the immediate vicinity of the portal. Due to the strong impact of open roads a 50 % traffic reduction scenario affecting tunnel and open roads emissions was computed. Although reductions of up to -25 µg/m3 may result

  3. Design and testing of an independently controlled urea SCR retrofit system for the reduction of NOx emissions from marine diesels.

    Science.gov (United States)

    Johnson, Derek R; Bedick, Clinton R; Clark, Nigel N; McKain, David L

    2009-05-15

    Diesel engine emissions for on-road, stationary and marine applications are regulated in the United States via standards set by the Environmental Protection Agency (EPA). A major component of diesel exhaust that is difficult to reduce is nitrogen oxides (NOx). Selective catalytic reduction (SCR) has been in use for many years for stationary applications, including external combustion boilers, and is promising for NOx abatement as a retrofit for mobile applications where diesel compression ignition engines are used. The research presented in this paper is the first phase of a program focused on the reduction of NOx by use of a stand-alone urea injection system, applicable to marine diesel engines typical of work boats (e.g., tugs). Most current urea SCR systems communicate with engine controls to predict NOx emissions based on signals such as torque and engine speed, however many marine engines in use still employ mechanical injection technology and lack electronic communication abilities. The system developed and discussed in this paper controls NOx emissions independentof engine operating parameters and measures NOx and exhaust flow using the following exhaust sensor inputs: absolute pressure, differential pressure, temperature, and NOx concentration. These sensor inputs were integrated into an independent controller and open loop architecture to estimate the necessary amount of urea needed, and the controller uses pulse width modulation (PWM) to power an automotive fuel injector for airless urea delivery. The system was tested in a transient test cell on a 350 hp engine certified at 4 g/bhp-hr of NOx, with a goal of reducing the engine out NOx levels by 50%. NOx reduction capabilities of 41-67% were shown on the non road transient cycle (NRTC) and ICOMIA E5 steady state cycles with system optimization during testing to minimize the dilute ammonia slip to cycle averages of 5-7 ppm. The goal of 50% reduction of NOx can be achieved dependent upon cycle. Further

  4. Exhaust particle and NOx emission performance of an SCR heavy duty truck operating in real-world conditions

    Science.gov (United States)

    Saari, Sampo; Karjalainen, Panu; Ntziachristos, Leonidas; Pirjola, Liisa; Matilainen, Pekka; Keskinen, Jorma; Rönkkö, Topi

    2016-02-01

    Particle and NOx emissions of an SCR equipped HDD truck were studied in real-world driving conditions using the "Sniffer" mobile laboratory. Real-time CO2 measurement enables emission factor calculation for NOx and particles. In this study, we compared three different emission factor calculation methods and characterised their suitability for real-world chasing experiments. The particle number emission was bimodal and dominated by the nucleation mode particles (diameter below 23 nm) having emission factor up to 1 × 1015 #/kgfuel whereas emission factor for soot (diameter above 23 nm that is consistent with the PMP standard) was typically 1 × 1014 #/kgfuel. The effect of thermodenuder on the exhaust particles indicated that the nucleation particles consisted mainly of volatile compounds, but sometimes there also existed a non-volatile core. The nucleation mode particles are not controlled by current regulations in Europe. However, these particles consistently form under atmospheric dilution in the plume of the truck and constitute a health risk for the human population that is exposed to those. Average NOx emission was 3.55 g/kWh during the test, whereas the Euro IV emission limit over transient testing is 3.5 g NOx/kWh. The on-road emission performance of the vehicle was very close to the expected levels, confirming the successful operation of the SCR system of the tested vehicle. Heavy driving conditions such as uphill driving increased both the NOx and particle number emission factors whereas the emission factor for soot particle number remains rather constant.

  5. In-use NOx emissions from model year 2010 and 2011 heavy-duty diesel engines equipped with aftertreatment devices.

    Science.gov (United States)

    Misra, Chandan; Collins, John F; Herner, Jorn D; Sax, Todd; Krishnamurthy, Mohan; Sobieralski, Wayne; Burntizki, Mark; Chernich, Don

    2013-07-16

    The California Air Resources Board (ARB) undertook this study to characterize the in-use emissions of model year (MY) 2010 or newer diesel engines. Emissions from four trucks: one equipped with an exhaust gas recirculation (EGR) and three equipped with EGR and a selective catalytic reduction (SCR) device were measured on two different routes with three different payloads using a portable emissions measurement system (PEMS) in the Sacramento area. Results indicated that brake-specific NOx emissions for the truck equipped only with an EGR were independent of the driving conditions. Results also showed that for typical highway driving conditions, the SCR technology is proving to be effective in controlling NOx emissions. However, under operations where the SCR's do not reach minimum operating temperature, like cold starts and some low load/slow speed driving conditions, NOx emissions are still elevated. The study indicated that strategies used to maintain exhaust temperature above a certain threshold, which are used in some of the newer SCRs, have the potential to control NOx emissions during certain low-load/slow speed driving conditions.

  6. New fuel air control strategy for reducing NOx emissions from corner-fired utility boilers at medium-low loads

    DEFF Research Database (Denmark)

    Zhao, Sinan; Fang, Qingyan; Yin, Chungen

    2017-01-01

    Due to the rapidly growing renewable power, the fossil fuel power plants have to be increasingly operated under large and rapid load change conditions, which can induce various challenges. This work aims to reduce NOx emissions of large-scale corner-fired boilers operated at medium–low loads....... The combustion characteristics and NOx emissions from a 1000 MWe corner-fired tower boiler under different loads are investigated experimentally and numerically. A new control strategy for the annular fuel air is proposed and implemented in the boiler, in which the secondary air admitted to the furnace through...... of the selective catalytic reduction (SCR) system by about 20% at medium–low loads, compared to those based on the original control. The new control strategy has also been successfully applied to two other corner-fired boilers to achieve a significant NOx emission reduction at partial loads. In all three...

  7. Equivalent Consumption Minimization Strategy for the Control of Real Driving NOx Emissions of a Diesel Hybrid Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Tobias Nüesch

    2014-05-01

    Full Text Available Motivated by the fact that the real driving NOx emissions (RDE of conventional diesel vehicles can exceed the legislation norms by far, a concept for the control of RDE with a diesel parallel hybrid electric vehicle (HEV is proposed. By extending the well-known equivalent consumption minimization strategy (ECMS, the power split degree of freedom is used to control the NOx emissions and the battery state of charge (SOC simultaneously. Through an appropriate formulation of the problem, the feedback control is shown to be separable into two dependent PI controllers. By hardware-in-the-loop (HIL experiments, as well as by simulations, the proposed method is shown to minimize the fuel consumption while tracking a given reference trajectory for both the NOx emissions and the battery SOC.

  8. THERMODYNAMIC MODELLING OF A PISTONS ENGINE: CALCULATION OF THE NOX EMISSIONS

    Directory of Open Access Journals (Sweden)

    N. Mahfoudi

    2015-07-01

    Full Text Available The internal combustion engines are under development remarkable these last decades, but they represent, currently, a very important source of polluting gas emissions. The nitrogen oxides (NOx form part of these polluting emissions, and have a harmful effect on human health, as well as the environment.Considering the complexity of the process of formation of the latter, many numerical simulations were developed, our work, allows the calculation of the nitrogen oxide rate (NO in exhaust gases, starting from the developed equations of the chemical kinetics, while being based on the thermal mechanism of Zeldovich. Simulation is carried out for a gasoline engine, and the results obtained show that: the maximum of NO concentrations corresponds to an equivalent ratio of 0,9. For leaner or richer equivalence ratios, concentration decreased. The NO concentrations depend of various parameters (spark timing angle, combustion duration, and engine speed.

  9. Overall evaluation of combustion and NO(x) emissions for a down-fired 600 MW(e) supercritical boiler with multiple injection and multiple staging.

    Science.gov (United States)

    Kuang, Min; Li, Zhengqi; Liu, Chunlong; Zhu, Qunyi

    2013-05-07

    To achieve significant reductions in NOx emissions and to eliminate strongly asymmetric combustion found in down-fired boilers, a deep-air-staging combustion technology was trialed in a down-fired 600 MWe supercritical utility boiler. By performing industrial-sized measurements taken of gas temperatures and species concentrations in the near wing-wall region, carbon in fly ash and NOx emissions at various settings, effects of overfire air (OFA) and staged-air damper openings on combustion characteristics, and NOx emissions within the furnace were experimentally determined. With increasing the OFA damper opening, both fluctuations in NOx emissions and carbon in fly ash were initially slightly over OFA damper openings of 0-40% but then lengthened dramatically in openings of 40-70% (i.e., NOx emissions reduced sharply accompanied by an apparent increase in carbon in fly ash). Decreasing the staged-air declination angle clearly increased the combustible loss but slightly influenced NOx emissions. In comparison with OFA, the staged-air influence on combustion and NOx emissions was clearly weaker. Only at a high OFA damper opening of 50%, the staged-air effect was relatively clear, i.e., enlarging the staged-air damper opening decreased carbon in fly ash and slightly raised NOx emissions. By sharply opening the OFA damper to deepen the air-staging conditions, although NOx emissions could finally reduce to 503 mg/m(3) at 6% O2 (i.e., an ultralow NOx level for down-fired furnaces), carbon in fly ash jumped sharply to 15.10%. For economical and environment-friendly boiler operations, an optimal damper opening combination (i.e., 60%, 50%, and 50% for secondary air, staged-air, and OFA damper openings, respectively) was recommended for the furnace, at which carbon in fly ash and NOx emissions attained levels of about 10% and 850 mg/m(3) at 6% O2, respectively.

  10. A new modeling approach for assessing the contribution of industrial and traffic emissions to ambient NOx concentrations

    Science.gov (United States)

    Chen, Shimon; Yuval; Broday, David M.

    2018-01-01

    The Optimized Dispersion Model (ODM) is uniquely capable of incorporating emission estimates, ambient air quality monitoring data and meteorology to provide reliable high-resolution (in both time and space) air quality estimates using non-linear regression. However, it was so far not capable of describing the effects of emissions from elevated sources. We formulated an additional term to extend the ODM such that these sources can be accounted for, and implemented it in modeling the fine spatiotemporal patterns of ambient NOx concentrations over the coastal plain of Israel. The diurnal and seasonal variation in the contribution of industry to the ambient NOx is presented, as well as its spatial features. Although industrial stacks are responsible for 88% of the NOx emissions in the study area, their contribution to ambient NOx levels is generally about 2% with a maximal upper bound of 27%. Meteorology has a major role in this source allocation, with the highest impact of industry in the summer months, when the wind is blowing inland past the coastal stacks and vertical mixing is substantial. The new Optimized Dispersion Model (ODM) out-performs both Inverse-Distance-Weighing (IDW) interpolation and a previous ODM version in predicting ambient NOx concentrations. The performance of the new model is thoroughly assessed.

  11. Public Health Impacts of Excess NOX Emissions from Volkswagen Diesel Passenger Vehicles: a comparison between Germany and the United States

    Science.gov (United States)

    Chossiere, G.; Barrett, S. R. H.; Malina, R.; Dedoussi, I. C.; Eastham, S. D.; Ashok, A.

    2016-12-01

    In September 2015, the Volkswagen Group admitted the use of an illegal emissions control system that activates during vehicle testing for regulatory purposes. Globally, 11 million diesel cars sold between 2008 and 2015 are affected, including about 2.6 million in Germany and 480,000 in the United States. On-road tests suggest that NOx emissions for these cars amount to 0.85 g/km on average, over four times the applicable European limit of 0.18 g/km and more than 20 times the corresponding EPA standard. This study quantifies and compares the human health impacts and costs associated with excess emissions from VW cars driven in Germany and in the United States. A distribution of emissions factors built from existing on-road measurements is combined with sales data and a vehicle fleet model to estimate total excess NOx emissions in each country. In Europe, we used the GEOS-Chem chemistry-transport model to predict the increase in population exposure to fine particulate matter and ozone due to the excess NOx emissions in Germany. The corresponding quantities in the US case were obtained using an adjoint-based air pollution model derived from the GEOS-Chem model. A set of concentration-response functions allowed us to estimate mortality outcomes in terms of early deaths in the US and in Europe. Integrated over the sales period (2008 - 2015), we estimate median mortality impacts from VW excess emissions in Germany to be 1,100 (95% CI: 0 to 3,000) early deaths in Europe, corresponding to 3.9 billion EUR (95% CI: 0 to 10 billion) in associated costs. Another 59 (95% CI: 10 to 150) early deaths is expected in the US as a result of excess emissions released in the country, corresponding to 450 million USD in social costs. We find that excess NOx emissions in Europe have 5 times greater health impacts per kilogram than those in the US due to the higher population density and more NOx-sensitive background conditions in Europe. The gas ratios in the two regions support this

  12. Effect of steam injection on nox emissions and performance of a single cylinder diesel engine fuelled with soy methyl ester

    Directory of Open Access Journals (Sweden)

    Manickam Madhavan V.

    2017-01-01

    Full Text Available Biodiesel attracts most of the researchers and automotive industries in recent years as an alternative fuel for diesel engines, because of its better lubricity property, higher cetane number, and less greenhouse gas emissions. The use of bio diesel leads to reduction in hydro carbons, carbon monoxide, and particulate matter, but increase in NOx emissions. Increase in biodiesel blends in standard diesel leads to increase in NOx emission. In this study, an attempt is made to reduce the NOx emis-sions of a diesel engine fueled with pure soy methyl ester (B100 with low pressure steam injection. Experiments were carried out and studied for both standard diesel and pure biodiesel of soy methyl ester with steam injection ratio of 5, 10, and 15% on mass ratio basis of air in the inlet manifold. The present study has shown that around 30% reduction in NOx can be achieved for the steam injection rate of 10% and considerable reduction for all other steam injection rates when compared to standard diesel and B100. It is also observed that steam injection having signifi-cant impact on reduction of other emissions such as HC, CO, and CO2. The study also noted marginal improvement in the engine brake power, brake thermal effi-ciency and reduction in specific fuel consumption at part loads and minor increase during peak load operation for the low pressure steam injection on B100.

  13. Reduction of NOx and particulate emissions from coal-fired boilers by modification of coal nozzles and combustion tuning

    Energy Technology Data Exchange (ETDEWEB)

    Chudnovsky, B.; Talanker, A.; Mugenstein, A.; Shpon, G.; Vikhansky, A.; Elperin, T.; Bar-Ziv, E.; Bockelie, M.; Eddings, E.; Sarofim, A.F. [Israel Electric Corporation, Haifa (Israel). Engineering Division

    2001-07-01

    In the present paper two issues are discussed: the effect of the burner replacement on boiler performance and NOx emissions and the effect of the burner replacement on performance and efficiency of electrostatic precipitators (ESP). We also have experimented with different coal types and found the coals that together with combustion tuning met commonly accepted emission limits for NOx (less than 600 mg/dNm{sup 3}) and levels of carbon in fly ash (LOI) (approximately 5-6%) for existing boilers without low NOx burners. Our measurements were accompanied by computer simulations of the combustion of the combustion process in the boiler. Special attention was paid to detailed simulation of the flow and ignition in the near-burner zone. 7 refs., 12 figs., 5 tabs.

  14. Atmospheric pollution reduction effect and regional predicament: An empirical analysis based on the Chinese provincial NOx emissions.

    Science.gov (United States)

    Ding, Lei; Liu, Chao; Chen, Kunlun; Huang, Yalin; Diao, Beidi

    2017-07-01

    Atmospheric pollution emissions have become a matter of public concern in recent years. However, most of the existing researches on NOx pollution are from the natural science and technology perspective, few studies have been conducted from an economic point, and regional differences have not been given adequate attention. This paper adopts provincial panel data from 2006 to 2013 and the LMDI model to analyze the key driving factors and regional dilemmas of NOx emissions. The results show that significant regional disparities still exit on NO x emissions and its reduction effect 27 provinces didn't accomplish their corresponding reduction targets. Economic development factor is the dominating driving factor of NO x emissions during the study period, while energy efficiency and technology improvement factors offset total NO x emissions in the majority of provinces. In addition, the industrial structure factor plays a more significant role in reducing the NO x emissions after 2011. Therefore, the government should consider all these factors as well as regional heterogeneity in developing appropriate pollution mitigating policies. It's necessary to change NOx emissions control attitude from original key areas control to divided-zone control, not only attaches great importance to the reduction of the original key areas, but also emphasizes the new potential hotspots with high NO x emissions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Co-controlling CO2 and NOx emission in China's cement industry: An optimal development pathway study

    Directory of Open Access Journals (Sweden)

    Xiang-Zhao Feng

    2018-03-01

    Full Text Available It is of important practical significance to reduce NOx emission and CO2 emission in China's cement industry. This paper firstly identifies key factors that influence China's future cement demand, and then uses the Gompertz model to project China's future cement demand and production. Furthermore, the multi-pollutant abatement planning model (MAP was developed based on the TIMES model to analyze the co-benefits of CO2 and NOx control in China's cement industry. During modeling analysis, three scenarios such as basic as usual scenario (BAU, moderately low carbon scenario (MLC, and radically low carbon scenario (RLC, were built according to different policy constraints and emission control goals. Moreover, the benefits of co-controlling NOx and CO2 emission in China's cement industry have been estimated. Finally, this paper proposes a cost-efficient, green, and low carbon development roadmap for the Chinese cement sector, and puts forwards countermeasures as follows: first, different ministries should enhance communication and coordination about how to promote the co-control of NOx and CO2 in cement industry. Second, co-control technology list should be issued timely for cement industry, and the R&D investment on new technologies and demonstration projects should be increased. Third, the phase-out of old cement capacity needs to be continued at policy level. Fourth, it is important to scientifically evaluate the relevant environmental impact and adverse motivation of ammonia production by NOx removal requirement in cement industry. Keywords: Cement industry, CO2 abatement, NOx reduction, Co-benefit analysis

  16. Cleaning up the air: effectiveness of air quality policy for SO2 and NOx emissions in China

    Science.gov (United States)

    van der A, Ronald J.; Mijling, Bas; Ding, Jieying; Elissavet Koukouli, Maria; Liu, Fei; Li, Qing; Mao, Huiqin; Theys, Nicolas

    2017-02-01

    Air quality observations by satellite instruments are global and have a regular temporal resolution, which makes them very useful in studying long-term trends in atmospheric species. To monitor air quality trends in China for the period 2005-2015, we derive SO2 columns and NOx emissions on a provincial level with improved accuracy. To put these trends into perspective they are compared with public data on energy consumption and the environmental policies of China. We distinguish the effect of air quality regulations from economic growth by comparing them relatively to fossil fuel consumption. Pollutant levels, per unit of fossil fuel, are used to assess the effectiveness of air quality regulations. We note that the desulfurization regulations enforced in 2005-2006 only had a significant effect in the years 2008-2009, when a much stricter control of the actual use of the installations began. For national NOx emissions a distinct decreasing trend is only visible from 2012 onwards, but the emission peak year differs from province to province. Unlike SO2, emissions of NOx are highly related to traffic. Furthermore, regulations for NOx emissions are partly decided on a provincial level. The last 3 years show a reduction both in SO2 and NOx emissions per fossil fuel unit, since the authorities have implemented several new environmental regulations. Despite an increasing fossil fuel consumption and a growing transport sector, the effects of air quality policy in China are clearly visible. Without the air quality regulations the concentration of SO2 would be about 2.5 times higher and the NO2 concentrations would be at least 25 % higher than they are today in China.

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

    Science.gov (United States)

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

    2012-11-20

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

  18. Performance of High Temperature Air Combustion Boiler with Low NOx Emission

    Science.gov (United States)

    Kobayashi, Hiromichi; Ito, Yoshihito; Tsuruta, Naoki; Yoshikawa, Kunio

    Thermal performance in the experiments and three-dimensional numerical simulations for a high temperature air combustion boiler where fuel can be efficiently combusted by high temperature preheated air (800°C-1000°C) is examined. The boiler can burn not only natural gas but also low calorific gas (e. g. full gasification gas obtained from coal or wastes). In the boiler, four regenerative burners are installed. This boiler has new features that not only air but also gasification gas is heated up to 900°C, and combination of burners is switched every 15 seconds where two burners are used as inlets of fuel and air and the other two burners are used as outlets of exhaust gas. Natural gas and syngas obtained from coal are burned. The NOx emission for each fuel is less than 50ppm. The heat transfer of three-dimensional calculation is predicted higher than that of experiment.

  19. Trend analysis of urban NO2 concentrations and the importance of direct NO2 emissions versus ozone/NOx equilibrium

    NARCIS (Netherlands)

    Keuken, M.; Roemer, M.; Elshout, S. van den

    2009-01-01

    The annual air quality standard of NO2 is often exceeded in urban areas near heavy traffic locations. Despite significant decrease of NOx emissions in 1986-2005 in the industrial and harbour area near Rotterdam, NO2 concentrations at the urban background remain at the same level since the end of the

  20. Method for the control of NOx emissions in long-range space travel

    Science.gov (United States)

    Xu, X. H.; Shi, Y.; Liu, S. H.; Wang, H. P.; Chang, S. G.; Fisher, J. W.; Pisharody, S.; Moran, M.; Wignarajah, K.

    2003-01-01

    The wheat straw, an inedible biomass that can be continuously produced in a space vehicle has been used to produce activated carbon for effective control of NOx emissions from the incineration of wastes. The optimal carbonization temperature of wheat straw was found to be around 600 degrees C when a burnoff of 67% was observed. The BET surface area of the activated carbon produced from the wheat straw reached as high as 300 m2/g. The presence of oxygen in flue gas is essential for effective adsorption of NO by activated carbon. On the contrary, water vapor inhibits the adsorption efficiency of NO. Consequently, water vapor in flue gas should be removed by drying agents before adsorption to ensure high NO adsorption efficiency. All of the NO in the flue gas was removed for more than 2 h by the activated carbons when 10% oxygen was present and the ratio of carbon weight to the flue gas flow rate (W/F) was 30 g min/L, with a contact time of 10.2 s. All of NO was reduced to N2 by the activated carbon at 450 degrees C with a W/F ratio of 15 g min/L and a contact time of 5.1 s. Reduction of the adsorbed NO also regenerated the activated carbon, and the regenerated activated carbon exhibited an improved NO adsorption efficiency. However, the reduction of the adsorbed NO resulted in a loss of carbon which was determined to be about 0.99% of the activated carbon per cycle of regeneration. The sufficiency of the amount of wheat straw in providing the activated carbon based on a six-person crew, such as the mission planned for Mars, has been determined. This novel approach for the control of NOx emissions is sustainable in a closed system such as the case in space travel. It is simple to operate and is functional under microgravity environment.

  1. Impact of passenger car NOX emissions on urban NO2 pollution - Scenario analysis for 8 European cities

    Science.gov (United States)

    Degraeuwe, Bart; Thunis, Philippe; Clappier, Alain; Weiss, Martin; Lefebvre, Wouter; Janssen, Stijn; Vranckx, Stijn

    2017-12-01

    Residents of large European cities are exposed to NO2 concentrations that often exceed the established air quality standards. Diesel cars have been identified as a major contributor to this situation; yet, it remains unclear to which levels the NOX emissions of diesel cars have to decrease to effectively mitigate urban NO2 pollution across Europe. Here, we take a continental perspective and model urban NO2 pollution in a generic street canyon of 8 major European cities for various NOX emission scenarios. We find that a reduction in the on-road NOX emissions of diesel cars to the Euro 6 level can in general decrease the regional and urban NO2 concentrations and thereby the frequency of exceedances of the NO2 air quality standard. High NO2 fractions in the NOX emissions of diesel cars tend to increase the urban NO2 concentrations only in proximity of intense road traffic typically found on artery roads in large cities like Paris and London. In cities with a low share of diesel cars in the vehicle fleet such as Athens or a high contribution from the NO2 background to the urban NO2 pollution such as Krakow, measures addressing heavy-duty vehicles, and the manufacturing, energy, and mining industry are necessary to decrease urban air pollution. We regard our model results as robust albeit subject to uncertainty resulting from the application of a generic street layout. With small modifications in the input parameters, our model could be used to assess the impact of NOX emissions from road transport on NO2 air pollution in any European city.

  2. On-road assessment of light duty vehicles in Delhi city: Emission factors of CO, CO2 and NOX

    Science.gov (United States)

    Jaiprakash; Habib, Gazala

    2018-02-01

    This study presents the technology based emission factors of gaseous pollutants (CO, CO2, and NOX) measured during on-road operation of nine passenger cars of diesel, gasoline, and compressed natural gas (CNG). The emissions from two 3-wheelers, and three 2-wheelers were measured by putting the vehicles on jacks and operating them according to Modified Indian Driving Cycle (MIDC) at no load condition. The emission factors observed in the present work were significantly higher than values reported from dynamometer study by Automotive Research Association of India (ARAI). Low CO (0.34 ± 0.08 g km-1) and high NOX (1.0 ± 0.4 g km-1) emission factors were observed for diesel passenger cars, oppositely high CO (2.2 ± 2.6 g km-1) and low NOX (1.0 ± 1.6 g km-1) emission factors were seen for gasoline powered cars. The after-treatment technology in diesel vehicles was effective in CO reduction. While the use of turbocharger in diesel vehicles to generate high combustion temperature and pressure produces more NOx, probably which may not be effectively controlled by after-treatment device. The after-treatment devices in gasoline powered Post-2010, Post-2005 vehicles can be acclaimed for reduced CO emissions compared to Post-2000 vehicles. This work presents a limited data set of emission factors from on-road operations of light duty vehicles, this limitation can be improved by further measurements of emissions from similar vehicles.

  3. Efficiency Analysis of Technological Methods for Reduction of NOx Emissions while Burning Hydrocarbon Fuels in Heat and Power Plants

    Directory of Open Access Journals (Sweden)

    S. M. Kabishov

    2013-01-01

    Full Text Available The paper contains a comparative efficiency analysis pertaining to application of existing technological methods for suppression of nitric oxide formation in heating boilers of heat generators. A special attention has been given to investigation of NOx  emission reduction while burning hydrocarbon fuel with the help of oxygen-enriched air. The calculations have demonstrated that while enriching oxidizer with the help of oxygen up to 50 % (by volume it is possible to reduce volume of NOx formation (while burning fuel unit by 21 %.

  4. Monthly top-down NOx emissions for China (2005-2012): A hybrid inversion method and trend analysis

    Science.gov (United States)

    Qu, Zhen; Henze, Daven K.; Capps, Shannon L.; Wang, Yi; Xu, Xiaoguang; Wang, Jun; Keller, Martin

    2017-04-01

    We develop an approach combining mass balance and four-dimensional variational (4D-Var) methods to facilitate inversion of decadal-scale total nitrogen oxides (NOx = NO + NO2) emissions. In 7 year pseudo-observation tests, hybrid posterior emissions have smaller normalized mean square error (NMSE) than that of mass balance when compared to true emissions in most cases and perform slightly better in detecting NOx emission magnitudes and trends. Using this hybrid method, OMI NO2 satellite observations and the GEOS-Chem chemical transport model, we find more than 30% increases of emissions over most of East China at the 0.5° × 0.667° grid cell level, leading to a 16% growth of emissions over all of China from 2005 to 2012, whereas emissions in several urban centers have decreased by 10-26% in the same period. From 2010 to 2012, a decline is found in the North China Plain, Hubei Province, and Pearl River Delta area, coinciding with China's enforcement of its twelfth "Five Year Plan." Changes in individual grid cell may be different from changes over the entire city or province, as exemplified by opposite trends in Beijing versus the Mentougou district of Beijing from 2005 to 2012. Also, NO2 columns do not necessarily have the same trend as NOx emissions due to their nonlinear response to emissions and the influence of meteorology, the latter alone which can cause up to 30% interannual changes in NO2 columns. Compared to recent bottom-up inventories, hybrid posterior emissions have the same seasonality, smaller emissions, and emission growth rate at the national scale.

  5. In-Use NOx Emissions from Diesel and Liquefied Natural Gas Refuse Trucks Equipped with SCR and TWC, Respectively.

    Science.gov (United States)

    Misra, Chandan; Ruehl, Chris; Collins, John; Chernich, Don; Herner, Jorn

    2017-06-20

    The California Air Resources Board (ARB) and the City of Sacramento undertook this study to characterize the in-use emissions from model year (MY) 2010 or newer diesel, liquefied natural gas (LNG), and hydraulic hybrid diesel engines during real-world refuse truck operation. Emissions from five trucks, two diesels equipped with selective catalytic reduction (SCR), two LNG's equipped with three-way catalyst (TWC), and one hydraulic hybrid diesel equipped with SCR, were measured using a portable emissions measurement system (PEMS) in the Sacramento area. Results showed that the brake-specific NOx emissions for the LNG trucks equipped with the TWC catalyst were lowest of all the technologies tested. Results also showed that the brake specific NOx emissions from the conventional diesel engines were significantly higher despite the exhaust temperature being high enough for proper SCR function. Like diesel engines, the brake specific NOx emissions from the hydraulic hybrid diesel also exceeded certification although this can be explained on the basis of the temperature profile. Future studies are warranted to establish whether the below average SCR performance observed in this study is a systemic issue or is it a problem specifically observed during this work.

  6. An experimental study on effect of coke ratio on SO2 and NOx emissions in sintering process

    Science.gov (United States)

    Wang, Hui; Zhang, Pu; Yang, Jingling

    2018-02-01

    By using the sinter cup experiment, the effects of different coke ratios of 0%, 25%, 50%, 75%, and 100% on the formation and total emissions of SO2 and NOx in the sintering process were studied with the Testo350 flue gas analyzer. The experimental results show that the emissions of SO2 and NOx are closely related to sintering process. With the increase of the coke proportion, the sintering temperature changes and the maximum peak time appears earlier. SO2 concentration has a bimodal distribution and NOx concentration has a triple peak. Besides, the both maximum peaks appear at the end of sintering. In addition, due to the increasing of the S and N contents in the fuel with the coke ratios from 0% to 100%, the amounts of SO2 and NOx emissions are raised respectively at 10.82 mg, 11.42 mg, 13.84 mg, 13.69 mg, 20.36 mg and 3.11 mg, 3.39 mg, 4.44 mg, 4.31 mg, 6.16 mg.

  7. Shifting primary energy source and NOx emission location with plug-in hybrid vehicles

    Science.gov (United States)

    Karman, Deniz

    2011-06-01

    Plug-in hybrid vehicles (PHEVs) present an interesting technological opportunity for using non-fossil primary energy in light duty passenger vehicles, with the associated potential for reducing air pollutant and greenhouse gas emissions, to the extent that the electric power grid is fed by non-fossil sources. This perspective, accompanying the article by Thompson et al (2011) in this issue, will touch on two other studies that are directly related: the Argonne study (Elgowainy et al 2010) and a PhD thesis from Utrecht (van Vliet 2010). Thompson et al (2011) have examined air quality effects in a case where the grid is predominantly fossil fed. They estimate a reduction of 7.42 tons/day of NOx from motor vehicles as a result of substituting electric VMTs for 20% of the light duty gasoline vehicle miles traveled. To estimate the impact of this reduction on air quality they also consider the increases in NOx emissions due to the increased load on electricity generating units. The NOx emission increases are estimated as 4.0, 5.5 and 6.3 tons for the Convenience, Battery and Night charging scenarios respectively. The net reductions are thus in the 1.1-3.4 tons/day range. The air quality modelling results presented show that the air quality impact from a ground-level ozone perspective is favorable overall, and while the effect is stronger in some localities, the difference between the three scenarios is small. This is quite significant and suggests that localization of the NOx emissions to point sources has a more pronounced effect than the absolute reductions achieved. Furthermore it demonstrates that localization of NOx emissions to electricity generating units by using PHEVs in vehicle traffic has beneficial effects for air quality not only by minimizing direct human exposure to motor vehicle emissions, but also due to reduced exposure to secondary pollutants (i.e. ozone). In an electric power grid with a smaller share of fossil fired generating units, the beneficial

  8. Effects of daily, high spatial resolution a priori profiles of satellite-derived NOx emissions

    Science.gov (United States)

    Laughner, J.; Zare, A.; Cohen, R. C.

    2016-12-01

    The current generation of space-borne NO2 column observations provides a powerful method of constraining NOx emissions due to the spatial resolution and global coverage afforded by the Ozone Monitoring Instrument (OMI). The greater resolution available in next generation instruments such as TROPOMI and the capabilities of geosynchronous platforms TEMPO, Sentinel-4, and GEMS will provide even greater capabilities in this regard, but we must apply lessons learned from the current generation of retrieval algorithms to make the best use of these instruments. Here, we focus on the effect of the resolution of the a priori NO2 profiles used in the retrieval algorithms. We show that for an OMI retrieval, using daily high-resolution a priori profiles results in changes in the retrieved VCDs up to 40% when compared to a retrieval using monthly average profiles at the same resolution. Further, comparing a retrieval with daily high spatial resolution a priori profiles to a more standard one, we show that emissions derived increase by 100% when using the optimized retrieval.

  9. Emission factors of air pollutants from CNG-gasoline bi-fuel vehicles: Part II. CO, HC and NOx.

    Science.gov (United States)

    Huang, Xiaoyan; Wang, Yang; Xing, Zhenyu; Du, Ke

    2016-09-15

    The estimation of emission factors (EFs) is the basis of accurate emission inventory. However, the EFs of air pollutants for motor vehicles vary under different operating conditions, which will cause uncertainty in developing emission inventory. Natural gas (NG), considered as a "cleaner" fuel than gasoline, is increasingly being used to reduce combustion emissions. However, information is scarce about how much emission reduction can be achieved by motor vehicles burning NG (NGVs) under real road driving conditions, which is necessary for evaluating the environmental benefits for NGVs. Here, online, in situ measurements of the emissions from nine bi-fuel vehicles were conducted under different operating conditions on the real road. A comparative study was performed for the EFs of black carbon (BC), carbon monoxide (CO), hydrocarbons (HCs) and nitrogen oxides (NOx) for each operating condition when the vehicles using gasoline and compressed NG (CNG) as fuel. BC EFs were reported in part I. The part II in this paper series reports the influence of operating conditions and fuel types on the EFs of CO, HC and NOx. Fuel-based EFs of CO showed good correlations with speed when burning CNG and gasoline. The correlation between fuel-based HC EFs and speed was relatively weak whether burning CNG or gasoline. The fuel-based NOx EFs moderately correlated with speed when burning CNG, but weakly correlated with gasoline. As for HC, the mileage-based EFs of gasoline vehicles are 2.39-12.59 times higher than those of CNG vehicles. The mileage-based NOx EFs of CNG vehicles are slightly higher than those of gasoline vehicles. These results would facilitate a detailed analysis of the environmental benefits for replacing gasoline with CNG in light duty vehicles. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Simulations of NOx Emissions from Low Emissions Discrete Jet Injector Combustor Tests

    Science.gov (United States)

    Ajmani, Kumud; Breisacher, Kevin

    2014-01-01

    An experimental and computational study was conducted to evaluate the performance and emissions characteristics of a candidate Lean Direct Injection (LDI) combustor configuration with a mix of simplex and airblast injectors. The National Combustion Code (NCC) was used to predict the experimentally measured EINOx emissions for test conditions representing low power, medium power, and high-power engine cycle conditions. Of the six cases modeled with the NCC using a reduced-kinetics finite-rate mechanism and lagrangian spray modeling, reasonable predictions of combustor exit temperature and EINOx were obtained at two high-power cycle conditions.

  11. Numerical investigation on the flow, combustion, and NOX emission characteristics in a 660 MWe tangential firing ultra-supercritical boiler

    Directory of Open Access Journals (Sweden)

    Wenjing Sun

    2016-02-01

    Full Text Available A three-dimensional numerical simulation was carried out to study the pulverized-coal combustion process in a tangentially fired ultra-supercritical boiler. The realizable k-ε model for gas coupled with discrete phase model for coal particles, P-1 radiation model for radiation, two-competing-rates model for devolatilization, and kinetics/diffusion-limited model for combustion process are considered. The characteristics of the flow field, particle motion, temperature distribution, species components, and NOx emissions were numerically investigated. The good agreement of the measurements and predictions implies that the applied simulation models are appropriate for modeling commercial-scale coal boilers. It is found that an ideal turbulent flow and particle trajectory can be observed in this unconventional pulverized-coal furnace. With the application of over-fire air and additional air, lean-oxygen combustion takes place near the burner sets region and higher temperature at furnace exit is acquired for better heat transfer. Within the limits of secondary air, more steady combustion process is achieved as well as the reduction of NOx. Furthermore, the influences of the secondary air, over-fire air, and additional air on the NOx emissions are obtained. The numerical results reveal that NOx formation attenuates with the decrease in the secondary air ratio (γ2nd and the ratio of the additional air to the over-fire air (γAA/γOFA was within the limits.

  12. Outstanding low temperature HC-SCR of NOx over platinum-group catalysts supported on mesoporous materials expecting diesel-auto emission regulation

    International Nuclear Information System (INIS)

    Komatsu, Tamikuni; Tomokuni, Keizou; Yamada, Issaku

    2006-01-01

    Outstanding low temperature HC-SCR of NOx over platinum-group catalysts supported on mesoporous materials, which does not rely on the conventional NOx-absorption-reduction-catalysts, is presented for the purpose of de-NOx of diesel-auto emissions. The established catalysts basically consist of mesoporous silica or metal-substituted mesoporous silicates for supports and platinum for active species, which is operated under lean- and rich-conditions. The new catalysts are very active at 150-200 o C and free from difficult problems of SOx-deactivation and hydrothermal ageing of the NOx-absorption-reduction catalyst. (author)

  13. Allocating emissions to 4 km and 1 km horizontal spatial resolutions and its impact on simulated NOx and O3 in Houston, TX

    Science.gov (United States)

    Pan, Shuai; Choi, Yunsoo; Roy, Anirban; Jeon, Wonbae

    2017-09-01

    A WRF-SMOKE-CMAQ air quality modeling system was used to investigate the impact of horizontal spatial resolution on simulated nitrogen oxides (NOx) and ozone (O3) in the Greater Houston area (a non-attainment area for O3). We employed an approach recommended by the United States Environmental Protection Agency to allocate county-based emissions to model grid cells in 1 km and 4 km horizontal grid resolutions. The CMAQ Integrated Process Rate analyses showed a substantial difference in emissions contributions between 1 and 4 km grids but similar NOx and O3 concentrations over urban and industrial locations. For example, the peak NOx emissions at an industrial and urban site differed by a factor of 20 for the 1 km and 8 for the 4 km grid, but simulated NOx concentrations changed only by a factor of 1.2 in both cases. Hence, due to the interplay of the atmospheric processes, we cannot expect a similar level of reduction of the gas-phase air pollutants as the reduction of emissions. Both simulations reproduced the variability of NASA P-3B aircraft measurements of NOy and O3 in the lower atmosphere (from 90 m to 4.5 km). Both simulations provided similar reasonable predictions at surface, while 1 km case depicted more detailed features of emissions and concentrations in heavily polluted areas, such as highways, airports, and industrial regions, which are useful in understanding the major causes of O3 pollution in such regions, and to quantify transport of O3 to populated communities in urban areas. The Integrated Reaction Rate analyses indicated a distinctive difference of chemistry processes between the model surface layer and upper layers, implying that correcting the meteorological conditions at the surface may not help to enhance the O3 predictions. The model-observation O3 bias in our studies (e.g., large over-prediction during the nighttime or along Gulf of Mexico coastline), were due to uncertainties in meteorology, chemistry or other processes. Horizontal grid

  14. Apparatus and method for burning a lean, premixed fuel/air mixture with low NOx emission

    Science.gov (United States)

    Kostiuk, Larry W.; Cheng, Robert K.

    1996-01-01

    An apparatus for enabling a burner to stably burn a lean fuel/air mixture. The burner directs the lean fuel/air mixture in a stream. The apparatus comprises an annular flame stabilizer; and a device for mounting the flame stabilizer in the fuel/air mixture stream. The burner may include a body having an internal bore, in which case, the annular flame stabilizer is shaped to conform to the cross-sectional shape of the bore, is spaced from the bore by a distance greater than about 0.5 mm, and the mounting device mounts the flame stabilizer in the bore. An apparatus for burning a gaseous fuel with low NOx emissions comprises a device for premixing air with the fuel to provide a lean fuel/air mixture; a nozzle having an internal bore through which the lean fuel/air mixture passes in a stream; and a flame stabilizer mounted in the stream of the lean fuel/air mixture. The flame stabilizer may be mounted in the internal bore, in which case, it is shaped and is spaced from the bore as just described. In a method of burning a lean fuel/air mixture, a lean fuel/air mixture is provided, and is directed in a stream; an annular eddy is created in the stream of the lean fuel/air mixture; and the lean fuel/air mixture is ignited at the eddy.

  15. The use of rice hulls for sustainable control of NOx emissions in deep space missions

    Energy Technology Data Exchange (ETDEWEB)

    Xu, X.H.; Shi, Y.; Chang, S.G.; Fisher, J.W.; Pisharody, S.; Moran, M.J.; Wignarajah, K.

    2001-12-21

    The use of the activated carbon produced from rice hulls to control NOx emissions for the future deep space missions has been demonstrated. The optimal carbonization temperature range was found to be between 600 C and 750 C. The burnoff of 61.8% was found at 700 C in pyrolysis and 750 C in activation. The BET surface area of the activated carbon from rice hulls was determined to be 172 m{sup 2}/g when prepared at 700 C. The presence of oxygen in flue gas is essential for effective adsorption of NO by the activated carbon. On the contrary, water vapor inhibits the adsorption efficiency of NO. Consequently, water vapor in flue gas should be removed by drying agents before adsorption to ensure high NO adsorption efficiency. All of NO in the flue gas was removed for more than one and a half hours when 10% oxygen was present and using a ratio of the carbon weight to the flue gas flow rate (W/F) of 15.4 g-min/L. The reduction of the adsorbed NO to form N{sub 2} can be effectively accomplished under anaerobic conditions at 550 C. For NO saturated activated carbon, the loss of carbon mass was determined to be about 0.16% of the activated carbon per cycle of regeneration. The reduction of the adsorbed NO also regenerates the activated carbon. The regenerated activated carbon exhibits improved NO adsorption efficiency.

  16. Impact of excess NOx emissions from diesel cars on air quality, public health and eutrophication in Europe

    Science.gov (United States)

    Jonson, J. E.; Borken-Kleefeld, J.; Simpson, D.; Nyíri, A.; Posch, M.; Heyes, C.

    2017-09-01

    Diesel cars have been emitting four to seven times more NOx in on-road driving than in type approval tests. These ‘excess emissions’ are a consequence of deliberate design of the vehicle’s after-treatment system, as investigations during the ‘Dieselgate’ scandal have revealed. Here we calculate health and environmental impacts of these excess NOx emissions in all European countries for the year 2013. We use national emissions reported officially under the UNECE Convention for Long-range Transport of Atmospheric Pollutants and employ the EMEP MSC-W Chemistry Transport Model and the GAINS Integrated Assessment Model to determine atmospheric concentrations and resulting impacts. We compare with impacts from hypothetical emissions where light duty diesel vehicles are assumed to emit only as much as their respective type approval limit value or as little as petrol cars of the same age. Excess NO2 concentrations can also have direct health impacts, but these overlap with the impacts from particulate matter (PM) and are not included here. We estimate that almost 10 000 premature deaths from PM2.5 and ozone in the adult population (age >30 years) can be attributed to the NOx emissions from diesel cars and light commercial vehicles in EU28 plus Norway and Switzerland in 2013. About 50% of these could have been avoided if diesel limits had been achieved also in on-road driving; and had diesel cars emitted as little NOx as petrol cars, 80% of these premature deaths could have been avoided. Ecosystem eutrophication impacts (critical load exceedances) from the same diesel vehicles would also have been reduced at similar rates as for the health effects.

  17. Final Technical Report on Investigation of Selective Non-Catalytic Processes for In-Situ Reduction of NOx and CO Emissions from Marine Gas Turbines and Diesel Engines

    National Research Council Canada - National Science Library

    Bowman, Craig

    1997-01-01

    .... These observations suggest the possibility of utilizing SNCR for reducing NO(x) emissions from marine gas turbines and Diesel engines by direct injection of a reductant species into the combustion chamber, possibly as a fuel...

  18. Effect of B20 and Low Aromatic Diesel on Transit Bus NOx Emissions Over Driving Cycles with a Range of Kinetic Intensity

    Energy Technology Data Exchange (ETDEWEB)

    Lammert, M. P.; McCormick, R. L.; Sindler, P.; Williams, A.

    2012-10-01

    Oxides of nitrogen (NOx) emissions for transit buses for up to five different fuels and three standard transit duty cycles were compared to establish whether there is a real-world biodiesel NOx increase for transit bus duty cycles and engine calibrations. Six buses representing the majority of the current national transit fleet and including hybrid and selective catalyst reduction systems were tested on a heavy-duty chassis dynamometer with certification diesel, certification B20 blend, low aromatic (California Air Resources Board) diesel, low aromatic B20 blend, and B100 fuels over the Manhattan, Orange County and UDDS test cycles. Engine emissions certification level had the dominant effect on NOx; kinetic intensity was the secondary driving factor. The biodiesel effect on NOx emissions was not statistically significant for most buses and duty cycles for blends with certification diesel, except for a 2008 model year bus. CARB fuel had many more instances of a statistically significant effect of reducing NOx. SCR systems proved effective at reducing NOx to near the detection limit on all duty cycles and fuels, including B100. While offering a fuel economy benefit, a hybrid system significantly increased NOx emissions over a same year bus with a conventional drivetrain and the same engine.

  19. Influence of enhanced Asian NOx emissions on ozone in the upper troposphere and lower stratosphere in chemistry–climate model simulations

    Directory of Open Access Journals (Sweden)

    C. Roy

    2017-01-01

    78.5 mW m−2 respectively. These elevated NOx emissions produce significant warming over the Tibetan Plateau and increase precipitation over India due to a strengthening of the monsoon Hadley circulation. However, increase in NOx emissions over India by 73 % (similar to the observed increase over China results in large ozone production over the Indo-Gangetic Plain and Tibetan Plateau. The higher ozone concentrations, in turn, induce a reversed monsoon Hadley circulation and negative precipitation anomalies over India. The associated subsidence suppresses vertical transport of NOx and ozone into the ASM anticyclone.

  20. Signal Control for Reducing Vehicle NOx and CO2 Emissions Based on Prediction of Arrival Traffic Flows at Intersections

    Science.gov (United States)

    Oda, Toshihiko

    Nitrogen oxide (NOx) and carbon dioxide (CO2) emissions from vehicles have been increasing every year because of the growing number of vehicles, and they cause serious environmental problems such as air pollution and global warming. To alleviate these problems, this paper proposes a new traffic signal control method for reducing vehicle NOx and CO2 emissions on arterial roads. To this end, we first model the amount of vehicle emissions as a function of the traffic delay and the number of stops at intersections. This step is necessary because it is difficult to obtain the amount of emissions directly using traffic control systems. Second, we introduce a signal control model in which the control parameters are continuously updated on the basis of predictions of arrival traffic flows at intersections. The signal timings are calculated in such a manner so as to minimize the weighted sum of the two emissions, which depend on the traffic flow. To evaluate the validity of this method, simulation experiments are carried out on an arterial road. The experiments show that the proposed method significantly outperforms existing methods in reducing both the emissions and travel time.

  1. Estimates of global biomass burning emissions for reactive greenhouse gases (CO, NMHCs, and NOx) and CO2

    Science.gov (United States)

    Jain, Atul K.; Tao, Zhining; Yang, Xiaojuan; Gillespie, Conor

    2006-03-01

    Open fire biomass burning and domestic biofuel burning (e.g., cooking, heating, and charcoal making) algorithms have been incorporated into a terrestrial ecosystem model to estimate CO2 and key reactive GHGs (CO, NOx, and NMHCs) emissions for the year 2000. The emissions are calculated over the globe at a 0.5° × 0.5° spatial resolution using tree density imagery, and two separate sets of data each for global area burned and land clearing for croplands, along with biofuel consumption rate data. The estimated global and annual total dry matter (DM) burned due to open fire biomass burning ranges between 5221 and 7346 Tg DM/yr, whereas the resultant emissions ranges are 6564-9093 Tg CO2/yr, 438-568 Tg CO/yr, 11-16 Tg NOx/yr (as NO), and 29-40 Tg NMHCs/yr. The results indicate that land use changes for cropland is one of the major sources of biomass burning, which amounts to 25-27% (CO2), 25 -28% (CO), 20-23% (NO), and 28-30% (NMHCs) of the total open fire biomass burning emissions of these gases. Estimated DM burned associated with domestic biofuel burning is 3,114 Tg DM/yr, and resultant emissions are 4825 Tg CO2/yr, 243 Tg CO/yr, 3 Tg NOx/yr, and 23 Tg NMHCs/yr. Total emissions from biomass burning are highest in tropical regions (Asia, America, and Africa), where we identify important contributions from primary forest cutting for croplands and domestic biofuel burning.

  2. Recent increases in nitrogen oxide (NOx) emissions from coal-fired electric generating units equipped with selective catalytic reduction.

    Science.gov (United States)

    McNevin, Thomas F

    2016-01-01

    The most effective control technology available for the reduction of oxides of nitrogen (NOx) from coal-fired boilers is selective catalytic reduction (SCR). Installation of SCR on coal-fired electric generating units (EGUs) has grown substantially since the onset of the U.S. Environmental Protection Agency's (EPA) first cap and trade program for oxides of nitrogen in 1999, the Ozone Transport Commission (OTC) NOx Budget Program. Installations have increased from 6 units present in 1998 in the states that encompass the current Cross-State Air Pollution Rule (CSAPR) ozone season program to 250 in 2014. In recent years, however, the degree of usage of installed SCR technology has been dropping significantly at individual plants. Average seasonal NOx emission rates increased substantially during the Clean Air Interstate Rule (CAIR) program. These increases coincided with a collapse in the cost of CAIR allowances, which declined to less than the cost of the reagent required to operate installed SCR equipment, and was accompanied by a 77% decline in delivered natural gas prices from their peak in June of 2008 to April 2012, which in turn coincided with a 390% increase in shale gas production between 2008 and 2012. These years also witnessed a decline in national electric generation which, after peaking in 2007, declined through 2013 at an annualized rate of -0.3%. Scaling back the use of installed SCR on coal-fired plants has resulted in the release of over 290,000 tons of avoidable NOx during the past five ozone seasons in the states that participated in the CAIR program. To function as designed, a cap and trade program must maintain allowance costs that function as a disincentive for the release of the air pollutants that the program seeks to control. If the principle incentive for reducing NOx emissions is the avoidance of allowance costs, emissions may be expected to increase if costs fall below a critical value, in the absence of additional state or federal

  3. Reducing diesel NOx and PM emissions of diesel buses and trucks.

    Science.gov (United States)

    2008-07-01

    The objective of the present investigation was development of a high efficiency : selective catalytic reduction (SCR) system for reducing diesel nitrogen oxides (NOx) and : particulate matters of diesel trucks. The investigation was divided into two ...

  4. Effects of various intake valve timings and spark timings on combustion, cyclic THC and NOX emissions during cold start phase with idle operation in CVVT engine

    International Nuclear Information System (INIS)

    Choi, Kwan Hee; Lee, Hyung Min; Hwang, In Goo; Myung, Cha Lee; Park, Sim Soo

    2008-01-01

    In a gasoline SI engine, valve events and spark timings put forth a major influence on overall efficiency, fuel economy, and exhaust emissions. Residual gases controlled by the valve overlap can be used to reduce NOx emissions and the spark retardation technique can be used to improve raw THC emissions and catalyst light-off performance during the cold start phase. This paper investigated the behaviors of the engine and its combustion characteristics with various intake valve timings and spark timings during the fast idle condition and cold start. And cyclic THC and NOx emissions were measured at the exhaust port and their formation mechanisms were examined with fast response gas analyzers. As a result, THCs and NOx were reduced by 35% and 23% with optimizing valve overlap and spark advance during the cold transient start phase. Consequently, the valve events and ignition timings were found to significantly affect combustion phenomena and cold-start emissions

  5. NOx Emission in Iron and Steel Production: A Review of Control Measures for Safe and Eco-Friendly Environment

    Directory of Open Access Journals (Sweden)

    U. A. Mukhtar

    2017-12-01

    Full Text Available Iron and steel manufacturing involved preparation of raw materials through processes such as sintering, pelletizing and coke making. During these processes, pollutants such as Sulphur (iv oxides (SO2 Carbon II oxides (CO, Nitrogen oxides (NOX, Volatile organic compounds (VOC and Particulate matter (PM etc. are emitted. The present work is aimed at describing some mitigation technologies of controlling emissions in iron and steel production. The processes involved in the production of iron and steel using Blast Furnace (BF and Basic Oxygen Furnace (BOF has been described. The mitigation technologies of controlling emissions were analyzed and discussed with environmental impacts based on the economical and technical factors. In this work, the data presented is based on existing reviews. The combination of low NOX burner (LNB and Selective catalytic reduction (SCR is capable of reducing emission for up to 90% and above. Emissions of other pollutants into the atmosphere as a result of ammonia slip, formation of acids and other gases are harmful to the environment and causes damage to the SCR systems. Installation and operation cost are the major impacts of the SCR technology in the process of iron and steel production.

  6. Decreasing NOx of a Low-Speed Two-Stroke Marine Diesel Engine by Using In-Cylinder Emission Control Measures

    Directory of Open Access Journals (Sweden)

    Liyan Feng

    2016-04-01

    Full Text Available The authors applied one-dimensional (1-D simulation and 3-D Computational Fluid Dynamics (CFD simulation to evaluate the potential of in-cylinder control methods on a low-speed 2-stroke marine engine to reach the International Maritime Organization (IMO Tier 3 NOx emissions standards. Reducing the combustion temperature is an important in-cylinder measure to decrease NOx emissions of marine diesel engines. Miller-cycle and Exhaust Gas Recirculation (EGR are effective methods to reduce the maximum combustion temperature and accordingly decrease NOx emissions. The authors’ calculation results indicate that with a combination of 2-stage turbocharging, a mild Miller-cycle and 10% EGR rate, the NOx emissions can be decreased by 48% without the increased Specific Fuel Oil Consumption (SFOC penalties; with a medium Miller-cycle and 10% EGR, NOx can be decreased by 56% with a slight increase of SFOC; with a medium Miller-cycle and 20% EGR, NOx can be decreased by 77% and meet IMO Tier 3 standards, but with the high price of a considerable increase of SFOC. The first two schemes are promising to meet IMO Tier 3 standards with good fuel economy if other techniques are combined.

  7. Reduction on NOx emissions on urban areas by changing specific vehicle fleets: effects on NO2 and O3 concentration

    Science.gov (United States)

    Goncalves, M.; Jimenez, P.; Baldasano, J.

    2007-12-01

    The largest amount of NOx emissions in urban areas comes from on-road traffic, which is the largest contributor to urban air pollution (Colvile et al., 2001). Currently different strategies are being tested in order to reduce its effects; many of them oriented to the reduction of the unitary vehicles emissions, by alternative fuels use (such as biofuels, natural gas or hydrogen) or introduction of new technologies (such as hybrid electric vehicles or fuel cells). Atmospheric modelling permits to predict their consequences on tropospheric chemistry (Vautard et al., 2007). Hence, this work assesses the changes on NO2 and O3 concentrations when substituting a 10 per cent of the urban private cars fleets by petrol hybrid electric cars (HEC) or by natural gas cars (NGC) in Madrid and Barcelona urban areas (Spain). These two cities are selected in order to highlight the different patterns of pollutants transport (inland vs. coastal city) and the different responses to emissions reductions. The results focus on a typical summertime episode of air pollution, by means of the Eulerian air quality model ARW- WRF/HERMES/CMAQ, applied with high resolution (1-hr, 1km2) since of the complexity of both areas under study. The detailed emissions scenarios are implemented in the HERMES traffic emissions module, based on the Copert III-EEA/EMEP-CORINAIR (Nztiachristos and Samaras, 2000) methodology. The HEC introduction reduces NOx emissions from on-road traffic in a 10.8 per cent and 8.2 per cent; and the NGC introduction in a 10.3 per cent and 7.8 per cent, for Madrid and Barcelona areas, respectively. The scenarios also affect the NMVOCs reduction (ranging from -3.1 to -6.9 per cent), influencing the tropospheric photochemistry through the NOx/NMVOCs ratio. The abatement of the NO photooxidation but also to the reduction on primary NO2 involves a decrease on NO2 levels centred on urban areas. For example, the NO2 24-hr average concentration in downtown areas reduces up to 8 per

  8. Biogenic nitrogen oxide emissions from soils ─ impact on NOx and ozone over West Africa during AMMA (African Monsoon Multidisciplinary Experiment: modelling study

    Directory of Open Access Journals (Sweden)

    J.-P. Chaboureau

    2008-05-01

    Full Text Available Nitrogen oxide biogenic emissions from soils are driven by soil and environmental parameters. The relationship between these parameters and NO fluxes is highly non linear. A new algorithm, based on a neural network calculation, is used to reproduce the NO biogenic emissions linked to precipitations in the Sahel on the 6 August 2006 during the AMMA campaign. This algorithm has been coupled in the surface scheme of a coupled chemistry dynamics model (MesoNH Chemistry to estimate the impact of the NO emissions on NOx and O3 formation in the lower troposphere for this particular episode. Four different simulations on the same domain and at the same period are compared: one with anthropogenic emissions only, one with soil NO emissions from a static inventory, at low time and space resolution, one with NO emissions from neural network, and one with NO from neural network plus lightning NOx. The influence of NOx from lightning is limited to the upper troposphere. The NO emission from soils calculated with neural network responds to changes in soil moisture giving enhanced emissions over the wetted soil, as observed by aircraft measurements after the passing of a convective system. The subsequent enhancement of NOx and ozone is limited to the lowest layers of the atmosphere in modelling, whereas measurements show higher concentrations above 1000 m. The neural network algorithm, applied in the Sahel region for one particular day of the wet season, allows an immediate response of fluxes to environmental parameters, unlike static emission inventories. Stewart et al (2008 is a companion paper to this one which looks at NOx and ozone concentrations in the boundary layer as measured on a research aircraft, examines how they vary with respect to the soil moisture, as indicated by surface temperature anomalies, and deduces NOx fluxes. In this current paper the model-derived results are compared to the observations and calculated fluxes presented by Stewart et

  9. A control-oriented real-time semi-empirical model for the prediction of NOx emissions in diesel engines

    International Nuclear Information System (INIS)

    D’Ambrosio, Stefano; Finesso, Roberto; Fu, Lezhong; Mittica, Antonio; Spessa, Ezio

    2014-01-01

    Highlights: • New semi-empirical correlation to predict NOx emissions in diesel engines. • Based on a real-time three-zone diagnostic combustion model. • The model is of fast application, and is therefore suitable for control-oriented applications. - Abstract: The present work describes the development of a fast control-oriented semi-empirical model that is capable of predicting NOx emissions in diesel engines under steady state and transient conditions. The model takes into account the maximum in-cylinder burned gas temperature of the main injection, the ambient gas-to-fuel ratio, the mass of injected fuel, the engine speed and the injection pressure. The evaluation of the temperature of the burned gas is based on a three-zone real-time diagnostic thermodynamic model that has recently been developed by the authors. Two correlations have also been developed in the present study, in order to evaluate the maximum burned gas temperature during the main combustion phase (derived from the three-zone diagnostic model) on the basis of significant engine parameters. The model has been tuned and applied to two diesel engines that feature different injection systems of the indirect acting piezoelectric, direct acting piezoelectric and solenoid type, respectively, over a wide range of steady-state operating conditions. The model has also been validated in transient operation conditions, over the urban and extra-urban phases of an NEDC. It has been shown that the proposed approach is capable of improving the predictive capability of NOx emissions, compared to previous approaches, and is characterized by a very low computational effort, as it is based on a single-equation correlation. It is therefore suitable for real-time applications, and could also be integrated in the engine control unit for closed-loop or feed-forward control tasks

  10. Quantifying Emission Controls of CO and NOx During the Victory Day Military Parade through Inverse Modelling with Ensemble Kalman Filter

    Science.gov (United States)

    Wu, H.; Tang, X.; Wang, Z.

    2016-12-01

    During the China Victory Day Parade in 2015, temporary emission control measures were conducted over Beijing and surrounding regions to guarantee the air quality of Beijing. This offers a great opportunity to explore the ability and limitations of the top-down emission estimation. In this study, we employed an ensemble Kalman filter (EnKF) in coupling with a Nested Air Quality Prediction Modeling System (NAQPMS) to establish a high temporal and spatial resolution emission inversion estimation scheme. The scheme enables to assimilated more than 400 surface observations of carbon monoxide (CO) and nitrogen dioxides (NO2) into a 5km×5km resolution model to inversely adjust the a priori emission inventory based on the Multi-resolution Emission Inventory for China (MEIC) for the base year of 2010. Fifty ensemble members and an offline hourly inverse analysis were employed during the four-week inverse period. Results suggested that the inverse estimation scheme significantly reduced the biases in the a prior emission inventory. Therefore, a new emission inventory was obtained and served as the base to compare with the inverse emission inventory during the China Victory Day Parade. Comparison between the new base emission inventory and the inverse emission inventory during the China Victory Day Parade revealed the temporal and spatial characters of the emission control measures over Beijing and surrounding areas. Significant emission reductions were found in Beijing-Tianjin-Hebei and surrounding areas. Meanwhile, NOx showed more reductions in areas around Beijing due to more rigorous vehicle control. This study highlighted the advantages and limitations of the EnKF-based emission estimation scheme. The uncertainties related to observation network, sampling strategy, and meteorological errors were also discussed.

  11. Unusually high soil nitrogen oxide emissions influence air quality in a high-temperature agricultural region.

    Science.gov (United States)

    Oikawa, P Y; Ge, C; Wang, J; Eberwein, J R; Liang, L L; Allsman, L A; Grantz, D A; Jenerette, G D

    2015-11-10

    Fertilized soils have large potential for production of soil nitrogen oxide (NOx=NO+NO2), however these emissions are difficult to predict in high-temperature environments. Understanding these emissions may improve air quality modelling as NOx contributes to formation of tropospheric ozone (O3), a powerful air pollutant. Here we identify the environmental and management factors that regulate soil NOx emissions in a high-temperature agricultural region of California. We also investigate whether soil NOx emissions are capable of influencing regional air quality. We report some of the highest soil NOx emissions ever observed. Emissions vary nonlinearly with fertilization, temperature and soil moisture. We find that a regional air chemistry model often underestimates soil NOx emissions and NOx at the surface and in the troposphere. Adjusting the model to match NOx observations leads to elevated tropospheric O3. Our results suggest management can greatly reduce soil NOx emissions, thereby improving air quality.

  12. NOx, FINE PARTICLE AND TOXIC METAL EMISSIONS FROM THE COMBUSTION OF SEWAGE SLUDGE/COAL MIXTURES: A SYSTEMATIC ASSESSMENT

    Energy Technology Data Exchange (ETDEWEB)

    Jost O.L. Wendt

    2002-08-15

    This research project focuses on pollutants from the combustion of mixtures of dried municipal sewage sludge (MSS) and coal. The objective is to determine the relationship between (1) fraction sludge in the sludge/coal mixture, and (2) combustion conditions on (a) NOx concentrations in the exhaust, (b) the size segregated fine and ultra-fine particle composition in the exhaust, and (c) the partitioning of toxic metals between vapor and condenses phases, within the process. The proposed study will be conducted in concert with an existing ongoing research on toxic metal partitioning mechanisms for very well characterized pulverized coals alone. Both high NOx and low NOx combustion conditions will be investigated (unstaged and staged combustion). Tradeoffs between CO2 control, NOx control, and inorganic fine particle and toxic metal emissions will be determined. Previous research has yielded data on trace metal partitioning for MSS by itself, with natural gas assist, for coal plus MSS combustion together, and for coal alone. We have re-evaluated the inhalation health effects of ash aerosol from combustion of MSS both by itself and also together with coal. We have concluded that ash from the co-combustion of MSS and coal is very much worse from an inhalation health point of view, than ash from either MSS by itself or coal by itself. The reason is that ZnO is not the ''bad actor'' as had been suspected before, but the culprit is, rather, sulfated Zn. The MSS supplies the Zn and the coal supplies the sulfur, and so it is the combination of coal and MSS that makes that process environmentally bad. If MSS is to be burned, it should be burned without coal, in the absence of sulfur.

  13. Simultaneous reduction of NOx, N{sub 2}O, SO{sub 2} emissions from a fluidized bed coal combustor using alternative bed material

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, T.; Asazuma, J.; Shinkai, M.; Matsunaga, S.; Yamagiwa, K.; Fujiwara, N. [Niigata University, Niigata (Japan). Dept. of Chemistry & Chemical Engienering

    2003-07-01

    A kind of porous alumina was employed as bed material of bubbling fluidized bed coal combustion instead of non-porous silica sand. The effect of the bed material on emissions of N{sub 2}O and NOx was evaluated using a bench-scale combustor. The present porous alumina suppressed N{sub 2}O emission. This result is explained by the catalytic activity of porous alumina to decompose N{sub 2}O. In addition, NOx emission with porous bed material was nearly the same as or lower than that for the sand bed. Thus the decrease in N{sub 2}O without increasing NOx was attained. A modification of desulfurization by limestone was proposed. Fine limestone particles were employed as sorbent in order to conduct SO{sub 2} capture in the freeboard. By employing fine particles, the contact between volatile matter and limestone, which is known to increase the emission of NOx, was avoided. Thus the increase in NOx emission during limestone feed was avoided.

  14. Top-down NOX emissions over European cities from LOTOS-EUROS simulated and OMI observed tropospheric NO2 columns using the Exponentially Modified Gaussian approach

    Science.gov (United States)

    Verstraeten, Willem W.; Folkert Boersma, K.; Douros, John; Williams, Jason E.; Eskes, Henk H.; Delcloo, Andy

    2017-04-01

    High nitrogen oxides concentrations at the surface (NOX = NO + NO2) impact humans and ecosystem badly and play a key role in tropospheric chemistry. Surface NOX emissions drive major processes in regional and global chemistry transport models (CTM). NOX contributes to the formation of acid rain, act as aerosol precursors and is an important trace gas for the formation of tropospheric ozone (O3). Via tropospheric O3, NOX indirectly affects the production of the hydroxyl radical which controls the chemical lifetime of key atmospheric pollutants and reactive greenhouse gases. High NOX emissions are mainly observed in polluted regions produced by anthropogenic combustion from industrial, traffic and household activities typically observed in large and densely populated urban areas. Accurate NOX inventories are essential, but state-of the- art emission databases may vary substantially and uncertainties are high since reported emissions factors may differ in order of magnitude and more. To date, the modelled NO2 concentrations and lifetimes have large associated uncertainties due to the highly non-linear small-scale chemistry that occurs in urban areas and uncertainties in the reaction rate data, missing nitrogen (N) species and volatile organic compounds (VOC) emissions, and incomplete knowledge of nitrogen oxides chemistry. Any overestimation in the chemical lifetime may mask missing NOX chemistry in current CTM's. By simultaneously estimating both the NO2 lifetime and concentrations, for instance by using the Exponentially Modified Gaussian (EMG), a better surface NOX emission flux estimate can be obtained. Here we evaluate if the EMG methodology can reproduce the emissions input from the tropospheric NO2 columns simulated by the LOTOS-EUROS (Long Term Ozone Simulation-European Ozone Simulation) CTM model. We apply the EMG methodology on LOTOS-EUROS simulated tropospheric NO2 columns for the period April-September 2013 for 21 selected European urban areas under windy

  15. Seasonal variability of NOx emissions over east China constrained by satellite observations: Implications for combustion and microbial sources

    Science.gov (United States)

    Wang, Yuxuan; McElroy, Michael B.; Martin, Randall V.; Streets, David G.; Zhang, Qiang; Fu, Tung-May

    2007-03-01

    Observations of tropospheric column densities of NO2 obtained from the Global Ozone Monitoring Experiment (GOME) for a 3-year period (1997, 1998, and 2000) are used to derive average seasonal variations in surface emissions of NOx from east China (100-123°E, 20-42°N). The retrieval allows for zonal variations in the contribution of the stratosphere to the NO2 column and removes a bias of ±10% on the seasonality of retrieved columns introduced by cloud screening. The top-down inventory is constructed using an inversion approach with a global 3-D chemical transport model (GEOS-Chem) and combined subsequently with the a priori inventory to develop an a posteriori inventory. The contribution of background NO2 arising from nonsurface sources (lightning) and long-range transport of emissions originating outside of east China is accounted for in the inversion. The a posteriori estimate of overall emissions for east China, 4.66 Tg N/yr (±30% uncertainty), is 33% higher than the a priori value and is shown to improve agreement with surface measurements of nitrate wet deposition and concentrations of NOy observed in China. On the basis of multiple constraints on the spatial and seasonal variations of combustion and microbial processes, the a posteriori inventory is partitioned among emissions from biomass burning, fuel combustion, and microbial activity (or soil emissions). Emission of NOx from biomass burning in east China is estimated as 0.08 TgN/yr ± 50% in the a posteriori inventory, increased by about a factor of 2 from the a priori estimate. The resulting a posteriori inventory for fuel combustion (3.72 TgN/yr ± 32%) is about 15% higher than the a priori and exhibits a distinct maximum in winter, in contrast to the weak seasonality indicated in the a priori inventory. The a posteriori value for the microbial source of NOx (0.85 TgN/yr ± 40%) is about a factor of 3 higher than the a priori value, amounting to 23% of combustion sources for east China and

  16. Modeling the impact of in-cylinder combustion parameters of DI engines on soot and NOx emissions at rated EGR levels using ANN approach

    International Nuclear Information System (INIS)

    Taghavifar, Hamid; Taghavifar, Hadi; Mardani, Aref; Mohebbi, Arash

    2014-01-01

    Highlights: • Effect of in-cylinder combustion parameters on soot and NOx emissions at rated EGR levels was studied. • ANN model was adopted to predict the emissions under the effect of combustion parameters. • A trainlm ANN with 5-19-17-2 structure denoted MSE equal to 0.0004627 as outperforming model. • Increment of EGR reduced the emissions where the equivalence ratio had contradictory effect. - Abstract: This study examines the effect of in-cylinder combustion parameters on soot and NOx emissions at rated EGR levels by using the data obtained from the CFD implemented code. The obtained data were subsequently used to construct an artificial neural network (ANN) model to predict the soot and NOx productions. To this aim, at three different engine speeds of 2000, 3000 and 4000 rpm, heat release rate, equivalence ratio, turbulence kinetic energy and temperature varied to obtain the relevant soot and NOx data at three EGR levels of 0.2, 0.3 and 0.4. It was discovered that wherein the application of higher EGR rates reduced the NOx as a result of mixture dilution, equivalence ratio increment makes soot production to be increased as well as NOx emission. It was also found that the application of higher EGR from 20% to 40% decreased soot mass fraction in the combustion chamber. Increment of EGR reduced the emissions where the equivalence ratio had contradictory effect on the produced emissions. Various ANN topological configurations and training algorithms were incorporated to yield the optimal solution to the modeling problem applying statistical criteria. Among the four adopted training algorithms of trainlm, trainscg, trainrp, and traingdx, the training function of Levenberg–Marquardt (trainlm) with topological structure of 5-19-17-2 denoted MSE equal to 0.0004627

  17. Structure, Stability and Emissions of Lean Direct Injection Combustion, including a Novel Multi-Point LDI System for NOx Reduction

    Science.gov (United States)

    Villalva Gomez, Rodrigo

    Experimental research on Lean Direct Injection (LDI) combustors for gas turbine applications is presented. LDI combustion is an alternative to lean premixed combustion which has the potential of equivalent reduction of oxides of nitrogen (NOx) emissions and of peak combustor exit temperatures, but without some drawbacks of premixed combustors, such as flashback and autoignition. Simultaneous observations of the velocity field and reaction zone of an LDI swirl-stabilized combustor with a mixing tube at atmospheric conditions, with the goal of studying the flame stabilization mechanism, are shown. The flame was consistently anchored at the shear layer formed by the high-speed reactants exiting the mixing tube and the low speed recirculation region. Individual image analysis of the location of the tip of the recirculation zone and tip of the reaction region confirmed previously observed trends, but showed that calculation of the distance between these two points for corresponding image pairs yields results no different than when calculated from random image pairs. This most likely indicates a lag in the anchoring of the flame to changes in the recirculation zone, coupled with significant stochastic variation. An alternate LDI approach, multi-point LDI (MLDI), is also tested experimentally. A single large fuel nozzle is replaced by multiple small fuel nozzles to improve atomization and reduce the total volume of the high-temperature, low velocity recirculation zones, reducing NOx formation. The combustor researched employs a novel staged approach to allow good performance across a wide range of conditions by using a combination of nozzle types optimized to various power settings. The combustor has three independent fuel circuits referenced as pilot, intermediate, and outer. Emissions measurements, OH* chemiluminescence imaging, and thermoacoustic instability studies were run in a pressurized combustion facility at pressures from 2.0 to 5.3 bar. Combustor performance

  18. Experimental and theoretical analysis of effects of N2, O2 and Ar in excess air on combustion and NOx emissions of a turbocharged NG engine

    International Nuclear Information System (INIS)

    Li, Weifeng; Liu, Zhongchang; Wang, Zhongshu; Xu, Yun; Wang, Jiankun

    2015-01-01

    Highlights: • We defined 7 effects of excess air and quantitative indicators on NOx emissions. • Contributions of N 2 , O 2 and Ar on the thermal effect are separately 85%, 14% and 1%. • Contributions of N 2 and Ar on the dilution effect are 98.8% and 1.2%, respectively. • The high level of N 2 in air is the main reason why NOx emissions decrease with λ. - Abstract: This paper presents the effects of N 2 , O 2 and Ar in excess air on combustion and NOx emissions of a natural gas spark-ignition engine. Based on Arrhenius Law and Zeldovich Mechanism, seven different kinds of effects were defined as well as their quantitative indicators. Excess air and N 2 were separately added into the intake charge with fuel remaining unchanged in a 6-cylinder turbocharged natural gas engine. The results show that the essential reason why NOx emissions vary with increasing excess air ratio (λ) is that the oxidation effect of O 2 varies with the in-cylinder temperature, which is controlled by the thermal effect of excess air. The contributions of N 2 , O 2 and Ar on the thermal effect are 82.6–86.1%, 13.3–16.7% and 0.6–0.7%, respectively. The chemical effect of O 2 is fully offset by the dilution effect of N 2 and Ar. The contributions of N 2 and Ar on the dilution effect are 98.31% and 1.69%, respectively. The increase of NOx emissions caused by O 2 is found to be increased first and then decreased with increasing λ. From the view of the composition of air, the high level of N 2 is the main reason why NOx emissions decrease significantly with increasing λ

  19. Impact of the 2008 Global Recession on air quality over the United States: Implications for surface ozone levels from changes in NOx emissions

    Science.gov (United States)

    Tong, Daniel; Pan, Li; Chen, Weiwei; Lamsal, Lok; Lee, Pius; Tang, Youhua; Kim, Hyuncheol; Kondragunta, Shobha; Stajner, Ivanka

    2016-09-01

    Satellite and ground observations detected large variability in nitrogen oxides (NOx) during the 2008 economic recession, but the impact of the recession on air quality has not been quantified. This study combines observed NOx trends and a regional chemical transport model to quantify the impact of the recession on surface ozone (O3) levels over the continental United States. The impact is quantified by simulating O3 concentrations under two emission scenarios: business-as-usual (BAU) and recession. In the BAU case, the emission projection from the Cross-State Air Pollution Rule is used to estimate the "would-be" NOx emission level in 2011. In the recession case, the actual NO2 trends observed from Air Quality System ground monitors and the Ozone Monitoring Instrument on the Aura satellite are used to obtain "realistic" changes in NOx emissions. The model prediction with the recession effect agrees better with ground O3 observations over time and space than the prediction with the BAU emission. The results show that the recession caused a 1-2 ppbv decrease in surface O3 concentration over the eastern United States, a slight increase (0.5-1 ppbv) over the Rocky Mountain region, and mixed changes in the Pacific West. The gain in air quality benefits during the recession, however, could be quickly offset by the much slower emission reduction rate during the post-recession period.

  20. Impact of the 2008 Global Recession on Air Quality over the United States: Implications for Surface Ozone Levels from Changes in NOx Emissions

    Science.gov (United States)

    Tong, Daniel; Pan, Li; Chen, Weiwei; Lamsal, Lok; Lee, Pius; Tang, Youhua; Kim, Hyuncheol; Kondragunta, Shobha; Stajner, Ivanka

    2016-01-01

    Satellite and ground observations detected large variability in nitrogen oxides (NOx) during the 2008 economic recession, but the impact of the recession on air quality has not been quantified. This study combines observed NOx trends and a regional chemical transport model to quantify the impact of the recession on surface ozone (O3) levels over the continental United States. The impact is quantified by simulating O3 concentrations under two emission scenarios: business-as-usual (BAU) and recession. In the BAU case, the emission projection from the Cross-State Air Pollution Rule is used to estimate the would-be NOx emission level in 2011. In the recession case, the actual NO2 trends observed from Air Quality System ground monitors and the Ozone Monitoring Instrument on the Aura satellite are used to obtain realistic changes in NOx emissions. The model prediction with the recession effect agrees better with ground O3 observations over time and space than the prediction with the BAU emission. The results show that the recession caused a 12ppbv decrease in surface O3 concentration over the eastern United States, a slight increase (0.51ppbv) over the Rocky Mountain region, and mixed changes in the Pacific West. The gain in air quality benefits during the recession, however, could be quickly offset by the much slower emission reduction rate during the post-recession period.

  1. The empirical relationship between satellite-derived tropospheric NO2 and fire radiative power and possible implications for fire emission rates of NOx

    Science.gov (United States)

    Schreier, Stefan F.; Richter, Andreas; Kaiser, Johannes W.; Schepaschenko, Dmitry; Shvidenko, Anatoly; Hilboll, Andreas; Burrows, John P.

    2014-05-01

    Vegetation fires across the globe have various impacts on Earth systems such as the atmosphere and biosphere. Every year, large quantities of biomass in different ecosystems are burned, either started by lightning strikes or caused by humans. Consequently, a considerable amount of trace gases (e.g. NOx) and aerosols is released into the atmosphere. As nitrogen oxides (NOx) affect atmospheric chemistry, air quality, and climate, a quantification of the total emissions is needed. Although several approaches have been developed for the estimation of NOx emissions from fires, they still suffer from large uncertainties. We present a simple statistical approach to estimate fire emission rates (FERs) of NOx based on the linear relationship between satellite-observed tropospheric NO2 vertical columns (TVC NO2) and fire radiative power (FRP). While the great advantage of the method is the spatial coverage of FERs and the application to various biomes and regions, the uncertainties in the two retrieved parameters can lead to uncertainties in the FERs. In general, the approach performs well for the tropical and subtropical regions where both the number and the spatial extent of vegetation fires are rather large throughout the fire season. However, due to the smaller number of fires and the patchy spatial occurrence, the estimation of FERs is more complicated in the boreal regions. Nevertheless, it is possible to derive FERs for some characteristic regions in the North American and Eurasian part of the boreal forest biome. The estimated FERs of NOx for the dominating types of vegetation burned are lowest for open shrublands, savannas, and boreal forest (0.28-1.03 g NOx s-1 MW-1) and highest for croplands and woody savannas (0.82-1.56 g NOx s-1 MW-1). Interestingly, there are large regional discrepancies of up to 40 % observed for evergreen broadleaf forest and boreal forest. Possible explanations for these regional discrepancies are discussed.

  2. Urban eddy covariance measurements reveal significant missing NOx emissions in Central Europe.

    Science.gov (United States)

    Karl, T; Graus, M; Striednig, M; Lamprecht, C; Hammerle, A; Wohlfahrt, G; Held, A; von der Heyden, L; Deventer, M J; Krismer, A; Haun, C; Feichter, R; Lee, J

    2017-05-30

    Nitrogen oxide (NO x ) pollution is emerging as a primary environmental concern across Europe. While some large European metropolitan areas are already in breach of EU safety limits for NO 2 , this phenomenon does not seem to be only restricted to large industrialized areas anymore. Many smaller scale populated agglomerations including their surrounding rural areas are seeing frequent NO 2 concentration violations. The question of a quantitative understanding of different NO x emission sources is therefore of immanent relevance for climate and air chemistry models as well as air pollution management and health. Here we report simultaneous eddy covariance flux measurements of NO x , CO 2 , CO and non methane volatile organic compound tracers in a city that might be considered representative for Central Europe and the greater Alpine region. Our data show that NO x fluxes are largely at variance with modelled emission projections, suggesting an appreciable underestimation of the traffic related atmospheric NO x input in Europe, comparable to the weekend-weekday effect, which locally changes ozone production rates by 40%.

  3. NOx trade. Case studies

    International Nuclear Information System (INIS)

    Jantzen, J.

    2002-01-01

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

  4. Plume Evolution and NOx Lifetime in the Denver Metropolitan Area

    Science.gov (United States)

    Ebben, C. J.; Sparks, T.; Wooldridge, P. J.; Cohen, R. C.

    2016-12-01

    NOx (NOx≡NO+NO2) is abundant in urban areas due to its emission via combustion processes. As NOx is transported away from cities, it undergoes photochemical oxidation to produce a variety of nitrogen oxide products, including peroxynitrates (PNs), alkyl nitrates (ANs), and nitric acid (HNO3). These species have different loss mechanisms and lifetimes, meaning that ongoing nitrogen oxide chemistry may differ greatly in the near- and far-field of cities. Understanding the evolution of NOx and NOy (NOy≡NOx+PNs+ANs+HNO3+…) - including the relative balance between NOx oxidation products and their overall concentrations - as air masses are transported away from cities is imperative to constraining the lifetime of NOx and understanding how air quality regulations aimed at lowering NOx emissions might impact air quality in the near- and far-field of urban areas. We have used observations from the Front Range Air Pollution and Photochemistry Experiment (FRAPPÉ) to investigate the evolution of NOx in air masses originating from the Denver urban area, and our results are contrasted with examples from other cities.

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

    International Nuclear Information System (INIS)

    Anjuman, S.; Tahira, S.; Hizbullah, K.; Hizbullah, K.

    2011-01-01

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

  6. Reduction of NOx emission in tangential fired - furnace by changing the, mode of operation

    International Nuclear Information System (INIS)

    Chudnovsky, B.; Talanker, A.; Levin, L.; Kahana, S

    1998-01-01

    The present work analyses tile results of tests on 575 MW units with tangential firing furnace arrangement in sub-stoichiometric combustion. Tangential firing provides good conditions for implementing sub-stoichiometric combustion owing to the delivery scheme of pulverized coal and air. The furnace was tested in several different modes of operation (Over Fire Air, Bunkers Out Of Service, Excess air, Tilt etc.) to achieve low cost NOx reduction. Actual performance data are presented based on experiments made on lEC's boiler in M.D. 'B' power station

  7. Combustion and NOx emission characteristics with respect to staged-air damper opening in a 600 MWe down-fired pulverized-coal furnace under deep-air-staging conditions.

    Science.gov (United States)

    Kuang, Min; Li, Zhengqi; Wang, Zhihua; Jing, Xinjing; Liu, Chunlong; Zhu, Qunyi; Ling, Zhongqian

    2014-01-01

    Deep-air-staging combustion conditions, widely used in tangential-fired and wall-arranged furnaces to significantly reduce NOx emissions, are premature up to now in down-fired furnaces that are designed especially for industry firing low-volatile coals such as anthracite and lean coal. To uncover combustion and NOx emission characteristics under deep-air-staging conditions within a newly operated 600 MWe down-fired furnace and simultaneously understand the staged-air effect on the furnace performance, full-load industrial-size measurements taken of gas temperatures and species concentrations in the furnace, CO and NOx emissions in flue gas, and carbon in fly ash were performed at various staged-air damper openings of 10%, 20%, 30%, and 50%. Increasing the staged-air damper opening, gas temperatures along the flame travel (before the flame penetrating the staged-air zone) increased initially but then decreased, while those in the staged-air zone and the upper part of the hopper continuously decreased and increased, respectively. On opening the staged-air damper to further deepen the air-staging conditions, O2 content initially decreased but then increased in both two near-wall regions affected by secondary air and staged air, respectively, whereas CO content in both two regions initially increased but then decreased. In contrast to the conventional understanding about the effects of deep-air-staging conditions, here increasing the staged-air damper opening to deepen the air-staging conditions essentially decreased the exhaust gas temperature and carbon in fly ash and simultaneously increased both NOx emissions and boiler efficiency. In light of apparently low NOx emissions and high carbon in fly ash (i.e., 696-878 mg/m(3) at 6% O2 and 9.81-13.05%, respectively) developing in the down-fired furnace under the present deep-air-staging conditions, further adjustments such as enlarging the staged-air declination angle to prolong pulverized-coal residence times in the

  8. EVALUATION OF EMISSION OF CO, NO AND NOX IN EXHAUST OF DIESEL ENGINE FUELED WITH FUEL ADDITIVED

    Directory of Open Access Journals (Sweden)

    Gilson Rodrigo de Miranda

    2011-01-01

    Full Text Available Air pollution has emerged as major global problems. In the last decade, the development of new engines, the use of different forms of treatment of exhaust gases and the increase in fuel quality were used to reduce pollutants (regulated or not. Among the various developments to reduce emissions, the use of oxygenated additives to diesel and paraffin is a quick and effective measure to reduce pollutants. In this work we studied the influence of oxygenated compounds (diethyl ether (DEE, 1-dodecanol (DOD, 2-methoxy-acetate (MEA and terc-butanol (TERC and paraffin (heptane (HEPT and n- hexadecane (CET added to diesel in order to improve the quality of CO, NO and NOx in the exhaust of diesel engine, single cylinder. The fuels used in the studies are formulations of diesel reference, here named S10, which contains low sulfur (

  9. Influence of Operating Conditions and Coal Properties on NOx and N2O Emissions in Pressurized Fluidized Bed Combustion of Subbituminous Coals

    Czech Academy of Sciences Publication Activity Database

    Svoboda, Karel; Pohořelý, Michael

    2004-01-01

    Roč. 83, 7-8 (2004), s. 1095-1103 ISSN 0016-2361 R&D Projects: GA AV ČR IAA4072801 Institutional research plan: CEZ:AV0Z4072921 Keywords : NOx and N2O emissions * combustion Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.368, year: 2004

  10. Using hydroponic biomass to regulate NOx emissions in long range space travel

    Energy Technology Data Exchange (ETDEWEB)

    Xu, X.H.; Shi, Y.; Chang, S.G.; Fisher, J.; Pisharody, S.; Moran, M.; Wignarajah, K.

    2002-02-01

    The incineration of wastes is one of the most promising reclamation technologies being developed for life support in long range space travel. However, incineration in a closed environment will build up hazardous NOx if not regulated. A technology that can remove NOx under microgravity conditions without the need of expendables is required. Activated carbon prepared from inedible wheat straw and sweet potato stalk that were grown under hydroponic conditions has been demonstrated to be able to adsorb NO and reduce it to N{sub 2}. The high mineral content in the activated carbon prepared from hydroponic biomass prohibits high surface area production and results in inferior NO adsorption capacity. The removal of mineral from the carbon circumvents the aforementioned negative effect. The optimal production conditions to obtain maximum yield and surface area for the activated carbon have been determined. A parametric study on the NO removal efficiency by the activated carbon has been done. The presence of oxygen in flue gas is essential for effective adsorption of NO by the activated carbon. On the contrary, water vapor inhibits the adsorption efficiency of NO. The NO adsorption capacity and the duration before it exceeds the Space Maximum Allowable Concentration were determined. After the adsorption of NO, the activated carbon can be regenerated for reuse by heating the carbon bed under anaerobic conditions to above 500 C, when the adsorbed NO is reduced to N{sub 2}. The regenerated activated carbon exhibits improved NO adsorption efficiency. However, regeneration had burned off a small percentage of the activated carbon.

  11. Control and reduction of NOx emissions on light hydrocarbons combustion in fluidized bed combustors: a technological prospection surveys; Controle e reducao de emissoes de NOx durante queima de hidrocarbonetos leves em combustores a leito fluidizado: um estudo de prospeccao tecnologica

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Douglas Alves; Winter, Eduardo [Instituto Nacional da Propriedade Industrial (INPI), Rio de Janeiro, RJ (Brazil)

    2008-07-01

    The present paper aims a technological prospecting study of the main technological agents involved in industrial light hydrocarbons combustion process. More specifically, the work approaches technologies applied to nitrogen oxides emissions control and reduction. Nitrogen oxides are typically known as 'NOx' (NO, N{sub 2}O, NO{sub 2}). 'NOx' are byproducts from fuel burning in combustion systems, including also in fluidized bed combustion systems. The technological prospecting study employed 'technology foresight' as tool for evaluating the technological perspectives of the thermal generation, basis on environment protection. Such technological perspectives of the thermal generation were evaluated through invention patent documents. The query methodology for obtaining of patent documents employed a free patent base, known as ESPACENET. Additionally, the documents obtained were evaluated, considering beyond the countries and the publication dates, technological perspectives employed to 'NOx' emissions control and reduction. It is very important to highlight around 70% of the industrial technological information are just found in invention patent documents. (author)

  12. Modeling the regional impact of ship emissions on NOx and ozone levels over the Eastern Atlantic and Western Europe using ship plume parameterization

    Directory of Open Access Journals (Sweden)

    P. Pisoft

    2010-07-01

    Full Text Available In general, regional and global chemistry transport models apply instantaneous mixing of emissions into the model's finest resolved scale. In case of a concentrated source, this could result in erroneous calculation of the evolution of both primary and secondary chemical species. Several studies discussed this issue in connection with emissions from ships and aircraft. In this study, we present an approach to deal with the non-linear effects during dispersion of NOx emissions from ships. It represents an adaptation of the original approach developed for aircraft NOx emissions, which uses an exhaust tracer to trace the amount of the emitted species in the plume and applies an effective reaction rate for the ozone production/destruction during the plume's dilution into the background air. In accordance with previous studies examining the impact of international shipping on the composition of the troposphere, we found that the contribution of ship induced surface NOx to the total reaches 90% over remote ocean and makes 10–30% near coastal regions. Due to ship emissions, surface ozone increases by up to 4–6 ppbv making 10% contribution to the surface ozone budget. When applying the ship plume parameterization, we show that the large scale NOx decreases and the ship NOx contribution is reduced by up to 20–25%. A similar decrease was found in the case of O3. The plume parameterization suppressed the ship induced ozone production by 15–30% over large areas of the studied region. To evaluate the presented parameterization, nitrogen monoxide measurements over the English Channel were compared with modeled values and it was found that after activating the parameterization the model accuracy increases.

  13. Advancing Understanding of Emissions from Oil and Natural ...

    Science.gov (United States)

    Executive Summary Environmentally responsible development of oil and gas assets requires well-developed emissions inventories and measurement techniques to verify emissions and the effectiveness of control strategies. To accurately model the oil and gas sector impacts on air quality, it is critical to have accurate activity data, emission factors and chemical speciation profiles for volatile organic compounds (VOCs) and nitrogen oxides (NOx). This report describes a U.S. Environmental Protection Agency (EPA) Office of Research and Development (ORD) Region 8 Regional Applied Research Effort (RARE) effort executed in Fiscal Year (FY) 2014 to FY 2016 that aimed to improve information on upstream oil and production emissions and identify areas where future work is needed. The project involved both field activities and data analysis and synthesis work with emphasis on product-related VOC emissions from well pads. In oil and gas basins with significant condensate and oil production, VOC emissions from well pads primarily arise from the separation of gas and liquid products and the storage process, with the control of emissions usually accomplished by enclosed combustion devices (ECDs), such as flares. Fugitive emissions of VOCs can originate from leaks and from potentially ineffective control systems. In the case of ECDs, byproducts of incomplete combustion may produce more highly reactive ozone precursor species. For both compliance and scientific purposes, the abili

  14. Antioxidant (A-tocopherol acetate) effect on oxidation stability and NOx emission reduction in methyl ester of Annona oil operated diesel engine

    Science.gov (United States)

    Senthil, R.; Silambarasan, R.; Pranesh, G.

    2017-05-01

    There is a major drawback while using biodiesel as a alternate fuel for compression ignition diesel engine due to lower heating value, higher viscosity, higher density and higher oxides of nitrogen emission. To minimize these drawbacks, fuel additives can contribute towards engine performance and exhaust emission reduction either directly or indirectly. In this current work, the test was conducted to investigate the effect of antioxidant additive (A-tocopherol acetate) on oxidation stability and NOx emission in a of Annona methyl ester oil (MEAO) fueled diesel engine. The A-tocopherol acetate is mixed in different concentrations such as 0.01, 0.02, 0.03 and 0.04% with 100% by vol MEAO. It is concluded that the antioxidant additive very effective in increasing the oxidation stability and in controlling the NOx emission. Further, the addition of antioxidant additive is slight increase the HC, CO and smoke emissions. Hence, A-tocopherol acetate is very effective in controlling the NOx emission with MEAO operated diesel engine without any major modification.

  15. Influence of the overfire air ratio on the NO(x) emission and combustion characteristics of a down-fired 300-MW(e) utility boiler.

    Science.gov (United States)

    Ren, Feng; Li, Zhengqi; Chen, Zhichao; Fan, Subo; Liu, Guangkui

    2010-08-15

    Down-fired boilers used to burn low-volatile coals have high NO(x) emissions. To find a way of solving this problem, an overfire air (OFA) system was introduced on a 300 MW(e) down-fired boiler. Full-scale experiments were performed on this retrofitted boiler to explore the influence of the OFA ratio (the mass flux ratio of OFA to the total combustion air) on the combustion and NO(x) emission characteristics in the furnace. Measurements were taken of gas temperature distributions along the primary air and coal mixture flows, average gas temperatures along the furnace height, concentrations of gases such as O(2), CO, and NO(x) in the near-wall region and carbon content in the fly ash. Data were compared for five different OFA ratios. The results show that as the OFA ratio increases from 12% to 35%, the NO(x) emission decreases from 1308 to 966 mg/Nm(3) (at 6% O(2) dry) and the carbon content in the fly ash increases from 6.53% to 15.86%. Considering both the environmental and economic effect, 25% was chosen as the optimized OFA ratio.

  16. Improving combustion characteristics and NO(x) emissions of a down-fired 350 MW(e) utility boiler with multiple injection and multiple staging.

    Science.gov (United States)

    Kuang, Min; Li, Zhengqi; Xu, Shantian; Zhu, Qunyi

    2011-04-15

    Within a Mitsui Babcock Energy Limited down-fired pulverized-coal 350 MW(e) utility boiler, in situ experiments were performed, with measurements taken of gas temperatures in the burner and near the right-wall regions, and of gas concentrations (O(2) and NO) from the near-wall region. Large combustion differences between zones near the front and rear walls and particularly high NO(x) emissions were found in the boiler. With focus on minimizing these problems, a new technology based on multiple-injection and multiple-staging has been developed. Combustion improvements and NO(x) reductions were validated by investigating three aspects. First, numerical simulations of the pulverized-coal combustion process and NO(x) emissions were compared in both the original and new technologies. Good agreement was found between simulations and in situ measurements with the original technology. Second, with the new technology, gas temperature and concentration distributions were found to be symmetric near the front and rear walls. A relatively low-temperature and high-oxygen-concentration zone formed in the near-wall region that helps mitigate slagging in the lower furnace. Third, NO(x) emissions were found to have decreased by as much as 50%, yielding a slight decrease in the levels of unburnt carbon in the fly ash.

  17. Systematic Field Study of NO(x) Emission Control Methods for Utility Boilers.

    Science.gov (United States)

    Bartok, William; And Others

    A utility boiler field test program was conducted. The objectives were to determine new or improved NO (x) emission factors by fossil fuel type and boiler design, and to assess the scope of applicability of combustion modification techniques for controlling NO (x) emissions from such installations. A statistically designed test program was…

  18. Development and Application of a Virtual NOx Sensor for Robust Heavy Duty Diesel Engine Emission Control

    NARCIS (Netherlands)

    Mentink, P.; Seykens, X.; Escobar Valdivieso, D.

    2017-01-01

    To meet future emission targets, it becomes increasingly important to optimize the synergy between engine and aftertreatment system. By using an integrated control approach minimal fluid (fuel and DEF) consumption is targeted within the constraints of emission legislation during real-world

  19. Reduction of amine and biological antioxidants on NOx emissions powered by mango seed biodiesel

    Directory of Open Access Journals (Sweden)

    Velmurugan Kolanjiappan

    2017-01-01

    Full Text Available Este estudio analiza la influencia de la amina y algunos antioxidantes biológicos en la reducción de las emisiones de NOx en un motor diesel alimentado con B100 (100% volumen de éster metílico de semillas de mango y B20 (20% en volumen de semillas de mango y 80% en volumen de mezcla de combustible diesel, Se probaron tres antioxidantes de amina, p-fenilendiamina (PPD, etilendiamina (EDA y N, N’-difenil-1,4-fenilendiamina (DPPD y tres antioxidantes biológicos, diclorometano (DCM, acetato de alfa-tocoferol ( α -T y ácido L-ascórbico (L-asc.acid en un motor diesel kirloskar de cuatro tiempos refrigerado por agua, 5,9 KW de potencia. Hay cinco concentraciones usadas en la mezcla antioxidante de mezclas de biodiesel. Es decir, 0,005% -m, 0,010% -m, 0,025% -m, 0,05% -m y 0,1%, valores en los cuales %-m corresponde a la concentración molar empleada en la mezcla antioxidante. Los resultados muestran que la reducción consiguiente de NOx podría ser adquirida por la adhesión de aditivo antioxidante DPPD con la concentración de 0,025% de combustible B20 en un 15,4% y combustible B100 en un 39%. El aditivo DPPD aumentó las emisiones de CO más de 7,42% para el combustible B100 y 6,44% para el combustible B20. El DCM antioxidante biológico exhibe 0,235 g/kWh para combustible B100 y 0,297 g/kWh para combustible B20. Se ha comprobado que la emisión de humo ha aumentado con la adición de antioxidantes. Un ligero incremento en la eficiencia térmica del freno (0,91% se logra con la adición de antioxidantes a plena carga. Los resultados experimentales se comparan con el análisis de varianza y el resultado es simplemente el mismo que el de la experimentación.

  20. Computational intelligence approach for NOx emissions minimization in a coal-fired utility boiler

    International Nuclear Information System (INIS)

    Zhou Hao; Zheng Ligang; Cen Kefa

    2010-01-01

    The current work presented a computational intelligence approach used for minimizing NO x emissions in a 300 MW dual-furnaces coal-fired utility boiler. The fundamental idea behind this work included NO x emissions characteristics modeling and NO x emissions optimization. First, an objective function aiming at estimating NO x emissions characteristics from nineteen operating parameters of the studied boiler was represented by a support vector regression (SVR) model. Second, four levels of primary air velocities (PA) and six levels of secondary air velocities (SA) were regulated by using particle swarm optimization (PSO) so as to achieve low NO x emissions combustion. To reduce the time demanding, a more flexible stopping condition was used to improve the computational efficiency without the loss of the quality of the optimization results. The results showed that the proposed approach provided an effective way to reduce NO x emissions from 399.7 ppm to 269.3 ppm, which was much better than a genetic algorithm (GA) based method and was slightly better than an ant colony optimization (ACO) based approach reported in the earlier work. The main advantage of PSO was that the computational cost, typical of less than 25 s under a PC system, is much less than those required for ACO. This meant the proposed approach would be more applicable to online and real-time applications for NO x emissions minimization in actual power plant boilers.

  1. Multi-lateral emission trading: lessons from inter-state NOx control in the United States

    International Nuclear Information System (INIS)

    Farrell, A.

    2001-01-01

    Marketable emission permit mechanisms are increasingly proposed as efficient means of managing environmental pollution problems such as greenhouse gas emissions. Existing examples of emissions trading in the literature have so far been limited to domestic efforts put in place through the action of a national legislature, which has no parallel in international politics. This paper examines two efforts to establish multi-lateral emissions trading for nitrogen oxides among various states with the US. One, the Ozone Transport Commission's NO x Budget program is a success. The other, the Ozone Transport Assessment Group and the federal government's subsequent NO x SIP Call has not resulted in a multi-lateral emissions control program, let alone an efficient, market-based one. Due to the relative similarities of the states (compared to highly heterogeneous nations of the world) these are ''best case'' examples, and explaining the vast differences in outcomes will help explain the potential and the challenges in developing an international emission trading program to control greenhouse gas emissions. (author)

  2. NOx emission calculations for bulk carriers by using engine power probabilities as weighting factors.

    Science.gov (United States)

    Cheng, Chih-Wen; Hua, Jian; Hwang, Daw-Shang

    2017-10-01

    An important marine pollution issue identified by the International Maritime Organization (IMO) is NO x emissions; however, the stipulated method for determining the NO x certification value does not reflect the actual high emission factors of slow-speed two-stroke diesel engines over long-term slow steaming. In this study, an accurate method is presented for calculating the NO x emission factors and total amount of NO x emissions by using the actual power probabilities of the diesel engines in four types of bulk carriers. The proposed method is suitable for all types and purposes of diesel engines, is not restricted to any operating modes, and is highly accurate. Moreover, it is recommended that the IMO-stipulated certification value calculation method be modified accordingly to genuinely reduce the amount of NO x emissions. The successful achievement of this level of reduction will help improve the air quality, especially in coastal and port areas, and the health of local residents. As per the IMO, the NO x emission certification value of marine diesel engines having a rated power over 130 kW must be obtained using specified weighting factor (WF)-based calculation. However, this calculation fails to represent the current actual situation. Effective emission reductions of 6.91% (at sea) and 31.9% (in ports) were achieved using a mathematical model of power probability functions. Thus, we strongly recommend amending the certification value of NO x Technical Code 2008 (NTC 2008) by removing the WF constraints, such that the NO x emissions of diesel engines is lower than the Tier-limits at any load level to obtain genuine NO x emission reductions.

  3. Modelling NOX concentrations through CFD-RANS in an urban hot-spot using high resolution traffic emissions and meteorology from a mesoscale model

    Science.gov (United States)

    Sanchez, Beatriz; Santiago, Jose Luis; Martilli, Alberto; Martin, Fernando; Borge, Rafael; Quaassdorff, Christina; de la Paz, David

    2017-08-01

    Air quality management requires more detailed studies about air pollution at urban and local scale over long periods of time. This work focuses on obtaining the spatial distribution of NOx concentration averaged over several days in a heavily trafficked urban area in Madrid (Spain) using a computational fluid dynamics (CFD) model. A methodology based on weighted average of CFD simulations is applied computing the time evolution of NOx dispersion as a sequence of steady-state scenarios taking into account the actual atmospheric conditions. The inputs of emissions are estimated from the traffic emission model and the meteorological information used is derived from a mesoscale model. Finally, the computed concentration map correlates well with 72 passive samplers deployed in the research area. This work reveals the potential of using urban mesoscale simulations together with detailed traffic emissions so as to provide accurate maps of pollutant concentration at microscale using CFD simulations.

  4. Real-world NOx emissions of Euro V and Euro VI heavy duty vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Vermeulen, R.; Dekker, H.; Vonk, W.

    2012-04-15

    TNO regularly performs measurements to determine the in-service performance and durability with respect to the pollutant emissions of heavy-duty vehicles under representative driving conditions. The 2011 measurement programme yields new insights regarding the emission performance of the upcoming Euro VI technology for heavy-duty vehicles, mandatory as of 31 December 2013 and, together with the results from earlier performed programmes, leads to conclusions on the emission performance of past and present generations of heavy-duty vehicles (Euro V, EEV)

  5. Optimization under variability and uncertainty: a case study for NOx emissions control for a gasification system.

    Science.gov (United States)

    Chen, Jianjun; Frey, H Christopher

    2004-12-15

    Methods for optimization of process technologies considering the distinction between variability and uncertainty are developed and applied to case studies of NOx control for Integrated Gasification Combined Cycle systems. Existing methods of stochastic optimization (SO) and stochastic programming (SP) are demonstrated. A comparison of SO and SP results provides the value of collecting additional information to reduce uncertainty. For example, an expected annual benefit of 240,000 dollars is estimated if uncertainty can be reduced before a final design is chosen. SO and SP are typically applied to uncertainty. However, when applied to variability, the benefit of dynamic process control is obtained. For example, an annual savings of 1 million dollars could be achieved if the system is adjusted to changes in process conditions. When variability and uncertainty are treated distinctively, a coupled stochastic optimization and programming method and a two-dimensional stochastic programming method are demonstrated via a case study. For the case study, the mean annual benefit of dynamic process control is estimated to be 700,000 dollars, with a 95% confidence range of 500,000 dollars to 940,000 dollars. These methods are expected to be of greatest utility for problems involving a large commitment of resources, for which small differences in designs can produce large cost savings.

  6. A technical and economic assessment of fuel oil hydrotreating technology for steam power plant SO2 and NOx emissions control

    Directory of Open Access Journals (Sweden)

    peiman pourmoghaddam

    2016-12-01

    Full Text Available This work presents a simulation approach to the design and economic evaluation of fuel oil hydrotreating processes for the control of SO2 and NOx emission in an Iranian steam power plant. The percent of fuel oil desulphurization was estimated from the SO2 emissions standards for power plants. Based on two different scenarios according to (I European and (II Iranian standards, the design and simulation of hydrodesulphurization reactors, separation, heat recovery, and amine gas sweetening sections were performed and an economic assessment of the plant was investigated for each scenario. The results indicated the following: the cost price of each barrel of low sulfur fuel oil produced in such plants was estimated at  4.24 US$ for scenario (I and 3.17 US$ for scenario (II; the levelized cost of desulfurization in power production was estimated at 0.618 c/kWh for (I and 0.463 c/kWh for (II; and the social cost savings of replacing every barrel of low sulfur fuel oil instead of one barrel of high sulfur fuel oil were estimated at 26.7 US$ for (I and 13.6 US$ (II.

  7. Response of terrestrial N2O and NOx emissions to abrupt climate change

    International Nuclear Information System (INIS)

    Pfeiffer, Mirjam; Kaplan, Jed O

    2010-01-01

    Being a potent greenhouse gas, N 2 O emitted by the terrestrial biosphere during abrupt climate change events could have amplified externally forced warming. To investigate this possibility, we tested the sensitivity of terrestrial N 2 O emissions to an abrupt warming event by applying the ARVE-DGVM in combination with a novel scheme for process-based simulation of terrestrial N 2 O and NO x emissions at the Gerzensee site in Switzerland. In this study, we aim to quantify the magnitude of change in emissions for the abrupt climate change event that occurred at the transition from Oldest Dryas to Boel-ling during the last deglaciation. Using high-resolution multiproxy records obtained from the Gerzensee that cover the Late Glacial, we apply a prescribed vegetation change derived from the pollen record and temperature and precipitation reconstructions derived from δ 18 O in lake sediments. Changes in soil temperature and moisture are simulated by the ARVE-DGVM using the reconstructed paleoclimate as a driver. Our results show a pronounced increase in mean annual N 2 O and NO x emissions for the transition (by factor 2.55 and 1.97, respectively), with highest amounts generally being emitted during summer. Our findings suggest that summertime emissions are limited by soil moisture, while temperature controls emissions during winter. For the time between 14670 and 14620 cal. years BP, our simulated N 2 O emissions show increase rates as high as 1% per year, indicating that local reactions of emissions to changing climate could have been considerably faster than the atmospheric concentration changes observed in polar ice.

  8. Impacts and mitigation of excess diesel-related NOx emissions in 11 major vehicle markets.

    Science.gov (United States)

    Anenberg, Susan C; Miller, Joshua; Minjares, Ray; Du, Li; Henze, Daven K; Lacey, Forrest; Malley, Christopher S; Emberson, Lisa; Franco, Vicente; Klimont, Zbigniew; Heyes, Chris

    2017-05-25

    Vehicle emissions contribute to fine particulate matter (PM 2.5 ) and tropospheric ozone air pollution, affecting human health, crop yields and climate worldwide. On-road diesel vehicles produce approximately 20 per cent of global anthropogenic emissions of nitrogen oxides (NO x ), which are key PM 2.5 and ozone precursors. Regulated NO x emission limits in leading markets have been progressively tightened, but current diesel vehicles emit far more NO x under real-world operating conditions than during laboratory certification testing. Here we show that across 11 markets, representing approximately 80 per cent of global diesel vehicle sales, nearly one-third of on-road heavy-duty diesel vehicle emissions and over half of on-road light-duty diesel vehicle emissions are in excess of certification limits. These excess emissions (totalling 4.6 million tons) are associated with about 38,000 PM 2.5 - and ozone-related premature deaths globally in 2015, including about 10 per cent of all ozone-related premature deaths in the 28 European Union member states. Heavy-duty vehicles are the dominant contributor to excess diesel NO x emissions and associated health impacts in almost all regions. Adopting and enforcing next-generation standards (more stringent than Euro 6/VI) could nearly eliminate real-world diesel-related NO x emissions in these markets, avoiding approximately 174,000 global PM 2.5 - and ozone-related premature deaths in 2040. Most of these benefits can be achieved by implementing Euro VI standards where they have not yet been adopted for heavy-duty vehicles.

  9. NOx emissions from large point sources: variability in ozone production, resulting health damages and economic costs

    International Nuclear Information System (INIS)

    Mauzerall, D.L.; Namsoug Kim

    2005-01-01

    We present a proof-of-concept analysis of the measurement of the health damage of ozone (O 3 ) produced from nitrogen oxides (NO x =NO+NO 2 ) emitted by individual large point sources in the eastern United States. We use a regional atmospheric model of the eastern United States, the Comprehensive Air quality Model with Extensions (CAMx), to quantify the variable impact that a fixed quantity of NO x emitted from individual sources can have on the downwind concentration of surface O 3 , depending on temperature and local biogenic hydrocarbon emissions. We also examine the dependence of resulting O 3 -related health damages on the size of the exposed population. The investigation is relevant to the increasingly widely used 'cap and trade' approach to NO x regulation, which presumes that shifts of emission over time and space, holding the total fixed over the course of the summer O 3 season, will have minimal effect on the environmental outcome. By contrast, we show that a shift of a unit of NO x emissions from one place or time to another could result in large changes in resulting health effects due to O 3 formation and exposure. We indicate how the type of modeling carried out here might be used to attach externality-correcting prices to emissions. Charging emitters fees that are commensurate with the damage caused by their NO x emissions would create an incentive for emitters to reduce emissions at times and in locations where they cause the largest damage. (author)

  10. Car MAX-DOAS measurements around entire cities: quantification of NOx emissions from the cities of Mannheim and Ludwigshafen (Germany

    Directory of Open Access Journals (Sweden)

    U. Platt

    2010-06-01

    Full Text Available We present car Multi-Axis (MAX- DOAS observations of tropospheric NO2 carried out on circles around the cities of Mannheim and Ludwigshafen (Germany on 24 August 2006. Together with information on wind speed and direction, the total emissions of the encircled source(s are quantified from these measurements. In contrast to recent similar studies based on zenith scattered sun light (elevation angle of 90°, we use a MAX-DOAS instrument mounted on a car, which observes scattered sun light under different elevation angles (here 45°, and 90°. Compared to simple zenith sky observations, MAX-DOAS observations have higher sensitivity and reduced uncertainty, and avoid systematic offsets in the determination of the vertically integrated trace gas concentration. The determination of the absolute value of the integrated tropospheric trace gas concentrations is especially important for the calculation of absolute trace gas fluxes through arbitrary transects. However, even if emission sources are completely surrounded, systematic offsets in the measured vertically integrated trace gas concentration can lead to errors in the determined total emissions, especially for observations around extended areas. In this study we discuss and quantify different error sources. In most cases, the largest error source is the variability and imperfect knowledge of the wind field. In addition – depending on the trace species observed - also chemical transformations between the emission sources and the measurement location have to be considered. For that purpose we use local observations within the encircled area to quantify and/or correct these errors. From our observations we derive a total NOx emission from the Mannheim/Ludwigshafen area of (7.4±1.8×1024 molec/sec, which if assumed to be constant throughout the year would correspond to a total emission of 17 830±4340 t/yr (calculated with the mass of NO2 t/yr, consistent with existing emission estimates. From our

  11. A Spatial Panel Data Analysis of Economic Growth, Urbanization, and NOx Emissions in China

    Directory of Open Access Journals (Sweden)

    Xiangyu Ge

    2018-04-01

    Full Text Available Is nitrogen oxides emissions spatially correlated in a Chinese context? What is the relationship between nitrogen oxides emission levels and fast-growing economy/urbanization? More importantly, what environmental preservation and economic developing policies should China’s central and local governments take to mitigate the overall nitrogen oxides emissions and prevent severe air pollution at the provincial level in specific locations and their neighboring areas? The present study aims to tackle these issues. This is the first research that simultaneously studies the nexus between nitrogen oxides emissions and economic development/urbanization, with the application of a spatial panel data technique. Our empirical findings suggest that spatial dependence of nitrogen oxides emissions distribution exists at the provincial level. Through the investigation of the existence of an environmental Kuznets curve (EKC embedded within the Stochastic Impacts by Regression on Population, Affluence, and Technology (STIRPAT framework, we conclude something interesting: an inverse N-shaped EKC describes both the income-nitrogen oxides nexus and the urbanization-nitrogen oxides nexus. Some well-directed policy advice is provided to reduce nitrogen oxides in the future. Moreover, these results contribute to the literature on development and pollution.

  12. Multi Response Optimization of NOx Emission of a Stationary Diesel Engine Fuelled with Crude Rice Bran Oil Methyl Ester Optimisation à réponses multiples de l’émission de NOx d’un moteur Diesel stationnaire alimenté par de l’ester méthylique d’huile de riz brut

    OpenAIRE

    Saravanan S.; Nagarajan G.; Sampath S.

    2012-01-01

    In the present work, an attempt was made to reduce the NOx emission of crude rice bran oil methyl ester without any considerable increase in smoke density, when used as a fuel in a stationary CI engine. Three factors namely, fuel injection timing, Exhaust Gas Recirculation (EGR) and fuel injection pressure were chosen and their combined effect in controlling the NOx emission of a stationary Diesel engine fuelled with crude rice bran oil methyl ester was investigated. Three levels were chosen ...

  13. An overview of emissions of SO2 and NOx and the long-range transport of oxidized sulfur and nitrogen pollutants in East Asia.

    Science.gov (United States)

    Qu, Yu; An, Junling; He, Youjiang; Zheng, Jun

    2016-06-01

    The long-range transport of oxidized sulfur (sulfur dioxide (SO2) and sulfate) and oxidized nitrogen (nitrogen oxides (NOx) and nitrate) in East Asia is an area of increasing scientific interest and political concern. This paper reviews various published papers, including ground- and satellite-based observations and numerical simulations. The aim is to assess the status of the anthropogenic emissions of SO2 and NOx and the long-range transport of oxidized S and N pollutants over source and downwind region. China has dominated the emissions of SO2 and NOx in East Asia and urgently needs to strengthen the control of their emissions, especially NOx emissions. Oxidized S and N pollutants emitted from China are transported to Korea and Japan, due to persistent westerly winds, in winter and spring. However, the total contributions of China to S and N pollutants across Korea and Japan were not found to be dominant over longer time scales (e.g., a year). The source-receptor relationships for oxidized S and N pollutants in East Asia varied widely among the different studies. This is because: (1) the nonlinear effects of atmospheric chemistry and deposition processes were not well considered, when calculating the source-receptor relationships; (2) different meteorological and emission data inputs and solution schemes for key physical and chemical processes were used; and (3) different temporal and spatial scales were employed. Therefore, simulations using the same input fields and similar model configurations would be of benefit, to further evaluate the source-receptor relationships of the oxidized S and N pollutants. Copyright © 2016. Published by Elsevier B.V.

  14. Experimental Study of Effect of EGR Rates on NOx and Smoke Emission of LHR Diesel Engine Fueled with Blends of Diesel and Neem Biodiesel

    Science.gov (United States)

    Modi, Ashishkumar Jashvantlal; Gosai, Dipak Chimangiri; Solanki, Chandresh Maheshchandra

    2017-10-01

    Energy conservation and efficiency have been the quest of engineers concerned with internal combustion engine. Theoretically, if the heat rejected could be reduced, then the thermal efficiency would be improved, at least up to the limit set by the second law of thermodynamics. For current work a ceramic coated twin cylinder water-cooled diesel engine using blends of diesel and Neem biodiesel as fuel was evaluated for its performance and exhaust emissions. Multi cylinder vertical water cooled self-governed diesel engine, piston, top surface of cylinder head and liners were fully coated with partially stabilized zirconia as ceramic material attaining an adiabatic condition. Previous studies have reported that combustion of Neem biodiesel emitted higher NOx, while hydrocarbon and smoke emissions were lower than conventional diesel fuel. Exhaust gas recirculation (EGR) is one of the techniques being used to reduce NOx emission from diesel engines; because it decreases both flame temperature and oxygen concentration in the combustion chamber. The stationary diesel engine was run in laboratory at a high load condition (85% of maximum load), fixed speed (2000 rpm) and various EGR rates of 5-40% (with 5% increment). Various measurements like fuel flow, exhaust temperature, exhaust emission measurement and exhaust smoke test were carried out. The results indicate improved fuel economy and reduced pollution levels for the low heat rejection (LHR) engine. The results showed that, at 5% EGR with TB10, both NOx and smoke opacity were reduced by 26 and 15%, respectively. Furthermore, TB20 along with 10% EGR was also able to reduce both NOx and smoke emission by 34 and 30%, respectively compared to diesel fuel without EGR.

  15. Common Rail Direct Injection Mode of CI Engine Operation with Different Injection Strategies - A Method to Reduce Smoke and NOx Emissions Simultaneously

    Directory of Open Access Journals (Sweden)

    S. V. Khandal

    2018-03-01

    Full Text Available Compression ignition (CI engines are most efficient and robust prime movers used in transportation, power generation applications but suffer from the problems of higher level of exhaust smoke and NOx tailpipe emissions with increased use of fossil fuels. Alternative fuel that replaces diesel and at the same time that result in lower smoke and NOx emissions is presently needed. Therefore the main aim of this experimental study is to lower the smoke and NOx emissions and to use non edible oils that replace the diesel. For this locally available honge biodiesel (BHO and cotton seed biodiesel (BCO were selected as alternative fuels to power CI engine operated in common rail direct injection (CRDI mode. In the first part, optimum fuel injection timing (IT and injection pressure (IP for maximum engine brake thermal efficiency (BTE was obtained. In the second part, performance, combustion and emission characteristics of the CRDI engine was studied with two different fuel injectors having 6 and 7 holes each having 0.2 mm orifice diameter. The CRDI engine results obtained were compared with the baseline date reported. The combustion chamber (CC used for the study was toroidal re-entrant (TRCC. The experimental tests showed that BHO and BCO fuelled CRDI engine showed overall improved performance with 7 hole injector when engine was operated at optimized fuel IT of 10° before top dead centre (bTDC and IP of 900 bar. The smoke emission reduced by 20% to 26% and NOx reduced by 16% to 20% in diesel and biodiesel powered CRDI engine as compared to conventional CI mode besides replacing diesel by biodiesel fuel (BDF.

  16. Experimental Study of Effect of EGR Rates on NOx and Smoke Emission of LHR Diesel Engine Fueled with Blends of Diesel and Neem Biodiesel

    Science.gov (United States)

    Modi, Ashishkumar Jashvantlal; Gosai, Dipak Chimangiri; Solanki, Chandresh Maheshchandra

    2018-04-01

    Energy conservation and efficiency have been the quest of engineers concerned with internal combustion engine. Theoretically, if the heat rejected could be reduced, then the thermal efficiency would be improved, at least up to the limit set by the second law of thermodynamics. For current work a ceramic coated twin cylinder water-cooled diesel engine using blends of diesel and Neem biodiesel as fuel was evaluated for its performance and exhaust emissions. Multi cylinder vertical water cooled self-governed diesel engine, piston, top surface of cylinder head and liners were fully coated with partially stabilized zirconia as ceramic material attaining an adiabatic condition. Previous studies have reported that combustion of Neem biodiesel emitted higher NOx, while hydrocarbon and smoke emissions were lower than conventional diesel fuel. Exhaust gas recirculation (EGR) is one of the techniques being used to reduce NOx emission from diesel engines; because it decreases both flame temperature and oxygen concentration in the combustion chamber. The stationary diesel engine was run in laboratory at a high load condition (85% of maximum load), fixed speed (2000 rpm) and various EGR rates of 5-40% (with 5% increment). Various measurements like fuel flow, exhaust temperature, exhaust emission measurement and exhaust smoke test were carried out. The results indicate improved fuel economy and reduced pollution levels for the low heat rejection (LHR) engine. The results showed that, at 5% EGR with TB10, both NOx and smoke opacity were reduced by 26 and 15%, respectively. Furthermore, TB20 along with 10% EGR was also able to reduce both NOx and smoke emission by 34 and 30%, respectively compared to diesel fuel without EGR.

  17. 40 CFR 76.7 - Revised NOX emission limitations for Group 1, Phase II boilers.

    Science.gov (United States)

    2010-07-01

    ... Group 1, Phase II boilers. 76.7 Section 76.7 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... emission limitations for Group 1, Phase II boilers. (a) Beginning January 1, 2000, the owner or operator of a Group 1, Phase II coal-fired utility unit with a tangentially fired boiler or a dry bottom wall...

  18. Modeling analysis of urea direct injection on the NOx emission reduction of biodiesel fueled diesel engines

    International Nuclear Information System (INIS)

    An, H.; Yang, W.M.; Li, J.; Zhou, D.Z.

    2015-01-01

    Highlights: • The effects of urea direct injection on NO x emissions reduction was investigated. • Aqueous urea solution was proposed to be injected after the fuel injection process. • The optimized injection strategy achieved a reduction efficiency of 58%. • There were no severe impacts on the CO emissions and BSFC. - Abstract: In this paper, a numerical simulation study was conducted to explore the possibility of an alternative approach: direct aqueous urea solution injection on the reduction of NO x emissions of a biodiesel fueled diesel engine. Simulation studies were performed using the 3D CFD simulation software KIVA4 coupled with CHEMKIN II code for pure biodiesel combustion under realistic engine operating conditions of 2400 rpm and 100% load. The chemical behaviors of the NO x formation and urea/NO x interaction processes were modeled by a modified extended Zeldovich mechanism and urea/NO interaction sub-mechanism. To ensure an efficient NO x reduction process, various aqueous urea injection strategies in terms of post injection timing, injection angle, and injection rate and urea mass fraction were carefully examined. The simulation results revealed that among all the four post injection timings (10 °ATDC, 15 °ATDC, 20 °ATDC and 25 °ATDC) that were evaluated, 15 °ATDC post injection timing consistently demonstrated a lower NO emission level. The orientation of the aqueous urea injection was also shown to play a critical role in determining the NO x removal efficiency, and 50 degrees injection angle was determined to be the optimal injection orientation which gave the most NO x reduction. In addition, both the urea/water ratio and aqueous urea injection rate demonstrated important roles which affected the thermal decomposition of urea into ammonia and the subsequent NO x removal process, and it was suggested that 50% urea mass fraction and 40% injection rate presented the lowest NO emission levels. At last, with the optimized injection

  19. FIELD EVALUATION OF LOW-EMISSION COAL BURNER TECHNOLOGY ON UTILITY BOILERS VOLUME II. SECOND GENERATION LOW-NOX BURNERS

    Science.gov (United States)

    The report describes tests to evaluate the performance characteristics of three Second Generation Low-NOx burner designs: the Dual Register burner (DRB), the Babcock-Hitachi NOx Reducing (HNR) burner, and the XCL burner. The three represent a progression in development based on t...

  20. Aerosol and NOx emission factors and submicron particle number size distributions in two road tunnels with different traffic regimes

    Directory of Open Access Journals (Sweden)

    D. Imhof

    2006-01-01

    Full Text Available Measurements of aerosol particle number size distributions (18–700 nm, mass concentrations (PM2.5 and PM10 and NOx were performed in the Plabutsch tunnel, Austria, and in the Kingsway tunnel, United Kingdom. These two tunnels show different characteristics regarding the roadway gradient, the composition of the vehicle fleet and the traffic frequency. The submicron particle size distributions contained a soot mode in the diameter range D=80–100 nm and a nucleation mode in the range of D=20–40 nm. In the Kingsway tunnel with a significantly lower particle number and volume concentration level than in the Plabutsch tunnel, a clear diurnal variation of nucleation and soot mode particles correlated to the traffic density was observed. In the Plabutsch tunnel, soot mode particles also revealed a diurnal variation, whereas no substantial variation was found for the nucleation mode particles. During the night a higher number concentration of nucleation mode particles were measured than soot mode particles and vice versa during the day. In this tunnel with very high soot emissions during daytime due to the heavy-duty vehicle (HDV share of 18% and another 40% of diesel driven light-duty vehicles (LDV semivolatile species condense on the pre-existing soot surface area rather than forming new particles by homogeneous nucleation. With the low concentration of soot mode particles in the Kingsway tunnel, also the nucleation mode particles exhibit a diurnal variation. From the measured parameters real-world traffic emission factors were estimated for the whole vehicle fleet as well as differentiated into the two categories LDV and HDV. In the particle size range D=18–700 nm, each vehicle of the mixed fleet emits (1.50±0.08×1014 particles km-1 (Plabutsch and (1.26±0.10×1014 particles km-1 (Kingsway, while particle volume emission factors of 0.209±0.008 cm3 km-1 and 0.036±0.004 cm3 km-1, respectively, were obtained. PM1 emission factors of 104±4 mg

  1. Integrated Dry NOx/SO2 Emissions Control System, A DOE Assessment

    Energy Technology Data Exchange (ETDEWEB)

    National Energy Technology Laboratory

    2001-10-01

    The goal of the U.S. Department of Energy's (DOE) Clean Coal Technology (CCT) Program is to furnish the energy marketplace with a number of advanced, more efficient, and environmentally responsible coal utilization technologies through demonstration projects. These projects seek to establish the commercial feasibility of the most promising advanced coal technologies that have developed beyond the proof-of-concept stage. This document serves as a DOE post-project assessment (PPA) of a project selected in CCT Round III, the Integrated Dry NO{sub x}/SO{sub 2} Emissions Control System (IDECS), as described in a Report to Congress (U.S. Department of Energy 1991). The desire to reduce emissions of nitrogen oxides (NO, nitric oxide, and NO{sub 2}, nitrogen dioxide, collectively referred to as NO{sub x}) and sulfur dioxide (SO{sub 2}) by up to 70 percent at a minimum capital expenditure, while limiting waste production to dry solids that can be handled by conventional ash-removal equipment, prompted Public Service Company of Colorado (PSCC) to submit the proposal for the IDECS project. In March 1991, PSCC entered into a cooperative agreement with DOE to conduct the study. The project was sited at PSCC's Arapahoe Steam Electric Generating Station in Denver, Colorado. The purpose of this CCT project was to demonstrate the reduction of NO{sub x} and SO{sub 2} emissions by installing a combination of existing and emerging technologies, which were expected to work synergistically to reduce emissions. The technologies were low-NO{sub x} burners (LNBS), overfire air (OFA), and selective noncatalytic reduction (SNCR) for NO{sub x} reduction; and dry sorbent injection (DSI), both with and without flue-gas humidification (FGH), for SO{sub 2} reduction. DOE provided 50 percent of the total project funding of $26.2 million.

  2. A new scaling methodology for NO(x) emissions performance of gas burners and furnaces

    Science.gov (United States)

    Hsieh, Tse-Chih

    1997-11-01

    A general burner and furnace scaling methodology is presented, together with the resulting scaling model for NOsb{x} emissions performance of a broad class of swirl-stabilized industrial gas burners. The model is based on results from a set of novel burner scaling experiments on a generic gas burner and furnace design at five different scales having near-uniform geometric, aerodynamic, and thermal similarity and uniform measurement protocols. These provide the first NOsb{x} scaling data over the range of thermal scales from 30 kW to 12 MW, including input-output measurements as well as detailed in-flame measurements of NO, NOsb{x}, CO, Osb2, unburned hydrocarbons, temperature, and velocities at each scale. The in-flame measurements allow identification of key sources of NOsb{x} production. The underlying physics of these NOsb{x} sources lead to scaling laws for their respective contributions to the overall NOsb{x} emissions performance. It is found that the relative importance of each source depends on the burner scale and operating conditions. Simple furnace residence time scaling is shown to be largely irrelevant, with NOsb{x} emissions instead being largely controlled by scaling of the near-burner region. The scalings for these NOsb{x} sources are combined in a comprehensive scaling model for NOsb{x} emission performance. Results from the scaling model show good agreement with experimental data at all burner scales and over the entire range of turndown, staging, preheat, and excess air dilution, with correlations generally exceeding 90%. The scaling model permits design trade-off assessments for a broad class of burners and furnaces, and allows performance of full industrial scale burners and furnaces of this type to be inferred from results of small scale tests.

  3. Reduction of NOx Emission of a Diesel Engine with a Multiple Injection Pump by SCR Catalytic Converter

    Directory of Open Access Journals (Sweden)

    Vít Marek

    2016-01-01

    Full Text Available This paper deals with reduction of NOx-emission of a diesel engine with multiple injection pump by SCR catalytic converter. Main aim of the measurement was the detection of SCR catalyst converter efficiency. Tests were realized at the Research and Development workplace of Zetor Tractor a.s. Used engine was equipped with a multiple injection pump with electromagnetic regulator of a fuel charge. During the experiment selective catalytic reduction and diesel particulate filter were used as an after treatment of harmful pollutants reduction. Testing cycle of the eight-point test was chosen and Non-Road Steady Cycle (NRSC was maintained according to 97/68/EC directive. Results confirmed the dependencies between temperatures of SCR catalyst and exhaust gases and the volume of exhaust gases on efficiency of SCR catalyst. During the operation load of the engine, selective catalytic reduction reached efficiency over 90 %. Used after treatment system is suitable for reduction of harmful pollutants according to the Tier 4f norm.

  4. Effects of various meteorological conditions and spatial emission resolutions on the ozone concentration & ROG/NOx limitation in the Milan area (I)

    Science.gov (United States)

    Bärtsch-Ritter, N.; Keller, J.; Dommen, J.; Prévát, A. S. H.

    2003-02-01

    The three-dimensional photochemical model UAM-V is used to investigate the effects of various meteorological conditions and of the coarseness of emission inventories on the ozone concentration and ROG/NOx limitation of the ozone production in the Po Basin in the northern part of Italy. As a base case, the high ozone episode with up to 200 ppb on 13 May 1998 was modelled and previously thoroughly evaluated with measurements gained during a large field experiment. The performed variations in meteorology are applied to mixing height, air temperature, specific humidity and wind speed. Three coarser emission inventories are obtained by resampling from 3×3 km2 up to 54×54 km2 emission grids. The model results show that changes in meteorological input files have the largest effect on peak ozone. In the modelled ozone plume a slope of 10.1 ppb ozone/°C and in Milan of 2.8 ppb ozone/°C were found. The net ozone formation in northern Italy is more strongly temperature than humidity dependent, while the humidity is very important for the ROG/NOx limitation of the ozone production. For each of the meteorological variations (e.g. doubling the mixing height), the modelled ozone plume remains ROG limited for this case. A strong change towards NOx sensitivity in the ROG limited areas is only found if much coarser emission inventories were applied. Increasing ROG limited areas with increasing wind speed are found, because the ROG limited ozone chemistry induced by point sources is spread over a larger area. Simulations without point sources tend to increase the NOx limited areas.

  5. Full Useful Life (120,000 miles) Exhaust Emission Performance of a NOx Adsorber and Diesel Particle Filter Equipped Passenger Car and Medium-duty Engine in Conjunction with Ultra Low Sulfur Fuel (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Thornton, M.; Tatur, M.; Tomazic, D.; Weber, P.; Webb, C.

    2005-08-25

    Discusses the full useful life exhaust emission performance of a NOx (nitrogen oxides) adsorber and diesel particle filter equipped light-duty and medium-duty engine using ultra low sulfur diesel fuel.

  6. A FUEL-RICH PRECOMBUSTOR. FIELD EVALUATION OF LOW-EMISSION COAL BURNER TECHNOLOGY ON UTILITY BOILERS - VOLUME IV. ALTERNATE CON- CEPTS FOR SOX, NOX, AND PARTICULATE EMISSIONS CONTROL FROM

    Science.gov (United States)

    The report gives results a study of the use of precombustors for the simultaneous control of S02, NOx, and ash emissions from coal combustion. In Phase 1, exploratory testing was conducted on a small pilot scale--293 kW (million Btu/hr)-pulverized-coal-fired precombustor to ident...

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

    Energy Technology Data Exchange (ETDEWEB)

    Nick Degenstein; Minish Shah; Doughlas Louie

    2012-05-01

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

  8. Preliminary performance and operating results from the integrated dry NOx/SO2 emissions control system

    International Nuclear Information System (INIS)

    Hunt, T.; Schott, G.; Smith, R.; Muzio, L.; Jones, D.; Mali E.; Arrigoni, T.

    1993-01-01

    The Integrated Dry NO x /SO 2 Emissions Control System was installed at Public Service Company of Colorado's Arapaho 4 generating station in 1992 in cooperation with the U.S. Department of Energy (DOE) and and the Electric Power Research Institute (EPRI). This full scale 100 MWe demonstration combines low-NO x burners, overfire air, and selective noncatalytic reduction (SNCR) for NO x control and dry sorbent injection with humidification for SO 2 control. Operation and testing of the Integrated Dry NO x /SO 2 Emissions Control System began in August 1992 and will continue through mid 1994. Preliminary results of the NO x control technologies show that the original system goal of 70% NO x removal has been easily met and that NO x removals of up to 80% are possible at full load with the combustion and SNCR systems. Testing of the dry sorbent injection system with low sulfur coal began in April 1993 using a calcium-based reagent. A maximum SO 2 removal of 40% has been achieved with duct injection of commercial calcium hydroxide and humidification to a 25 degrees F approach to saturation. Sodium-based dry sorbent injection is expected to achieved up to a 70% SO 2 reduction

  9. Radiation processes for the control of NOx/SO2 emissions

    International Nuclear Information System (INIS)

    Dickson, L.W.; Singh, A.

    1988-01-01

    This report provides a brief review of the use of radiation for the treatment of flue gases and identifies areas for additional research. Two different radiation-based processes have been developed for the removal of nitrogen oxides and sulphur dioxide from the flue gases of coal-fired boilers. In the technique developed by the Ebara Corporation and Japan Atomic Energy Research Institute, ammonia is injected prior to the irradiation step to enhance the process efficiency and to yield a solid ammonium sulphate - ammonium nitrate product that may be used as a fertilizer. The process developed by the Research-Cottrell Corporation uses electron-beam irradiation downstream of a lime spray dryer to remove nitrogen oxides and to enhance the sulphur dioxide removal efficiency. Both of these processes require large quantities of electron-beam power and are currently expected to be more expensive than other available sulphur dioxide emission control technologies. Present emission control regulations in North America do not require the high degree of nitrogen oxide removal provided by the radiation-based processes. Research into the radiolytic oxidation of nitrogen oxides and sulphur dioxide, the radiolytic oxidation of NO x /SO 2 on solid sorbents, and the radiolytic oxidation of NO x /SO 2 in electric fields may lead to the development of more economical radiation treatment processes for flue gases. 44 refs

  10. Towards Understanding Methane Emissions from Abandoned Wells

    Science.gov (United States)

    Reconciliation of large-scale top-down methane measurements and bottom-up inventories requires complete accounting of source types. Methane emissions from abandoned oil and gas wells is an area of uncertainty. This presentation reviews progress to characterize the potential inv...

  11. 40 CFR 75.71 - Specific provisions for monitoring NOX and heat input for the purpose of calculating NOX mass...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Specific provisions for monitoring NOX and heat input for the purpose of calculating NOX mass emissions. 75.71 Section 75.71 Protection of... MONITORING NOX Mass Emissions Provisions § 75.71 Specific provisions for monitoring NOX and heat input for...

  12. Experimental and numerical investigations of the dry-low-NOx hydrogen micromix combustion chamber of an industrial gas turbine

    Directory of Open Access Journals (Sweden)

    A. Haj Ayed

    2015-09-01

    The study reveals great potential for the successful application of numerical flow simulation to predict flame structure and NOx emission level of micromix hydrogen combustion, help understanding the flow phenomena related with the micromixing, reaction zone and NOx formation and support further optimization of the burner performance.

  13. Limitations of ozone data assimilation with adjustment of NOx emissions: mixed effects on NO2 forecasts over Beijing and surrounding areas

    Directory of Open Access Journals (Sweden)

    X. Tang

    2016-05-01

    Full Text Available This study investigates a cross-variable ozone data assimilation (DA method based on an ensemble Kalman filter (EnKF that has been used in the companion study to improve ozone forecasts over Beijing and surrounding areas. The main purpose is to delve into the impacts of the cross-variable adjustment of nitrogen oxide (NOx emissions on the nitrogen dioxide (NO2 forecasts over this region during the 2008 Beijing Olympic Games. A mixed effect on the NO2 forecasts was observed through application of the cross-variable assimilation approach in the real-data assimilation (RDA experiments. The method improved the NO2 forecasts over almost half of the urban sites with reductions of the root mean square errors (RMSEs by 15–36 % in contrast to big increases of the RMSEs over other urban stations by 56–239 %. Over the urban stations with negative DA impacts, improvement of the NO2 forecasts (with 7 % reduction of the RMSEs was noticed at night and in the morning versus significant deterioration during daytime (with 190 % increase of the RMSEs, suggesting that the negative data assimilation impacts mainly occurred during daytime. Ideal-data assimilation (IDA experiments with a box model and the same cross-variable assimilation method confirmed the mixed effects found in the RDA experiments. In the same way, NOx emission estimation was improved at night and in the morning even under large biases in the prior emission, while it deteriorated during daytime (except for the case of minor errors in the prior emission. The mixed effects observed in the cross-variable data assimilation, i.e., positive data assimilation impacts on NO2 forecasts over some urban sites, negative data assimilation impacts over the other urban sites, and weak data assimilation impacts over suburban sites, highlighted the limitations of the EnKF under strong nonlinear relationships between chemical variables. Under strong nonlinearity between daytime ozone concentrations and

  14. Assessment of the Potential to Reduce Emissions from Road Transportation, Notably NOx, Through the Use of Alternative Vehicles and Fuels in the Great Smoky Mountains Region; TOPICAL

    International Nuclear Information System (INIS)

    Sheffield, J.

    2001-01-01

    Air pollution is a serious problem in the region of the Great Smoky Mountains. The U.S. Environmental Protection Agency (EPA) may designate non-attainment areas by 2003 for ozone. Pollutants include nitrogen oxides (NOx), sulfur dioxide (SO(sub 2)), carbon monoxide (CO), volatile organic compounds (VOCs), lead, and particulate matter (PM), which are health hazards, damage the environment, and limit visibility. The main contributors to this pollution are industry, transportation, and utilities. Reductions from all contributors are needed to correct this problem. While improvements are projected in each sector over the next decades, the May 2000 Interim Report issued by the Southern Appalachian Mountains Initiative (SAMI) suggests that the percentage of NOx emissions from transportation may increase. The conclusions are: (1) It is essential to consider the entire fuel cycle in assessing the benefits, or disadvantages, of an alternative fuel option, i.e., feedstock and fuel production, in addition to vehicle operation; (2) Many improvements to the energy efficiency of a particular vehicle and engine combination will also reduce emissions by reducing fuel use, e.g., engine efficiency, reduced weight, drag and tire friction, and regenerative braking; (3) In reducing emissions it will be important to install the infrastructure to provide the improved fuels, support the maintenance of advanced vehicles, and provide emissions testing of both local vehicles and those from out of state; (4) Public transit systems using lower emission vehicles can play an important role in reducing emissions per passenger mile by carrying passengers more efficiently, particularly in congested areas. However, analysis is required for each situation; (5) Any reduction in emissions will be welcome, but the problems of air pollution in our region will not be solved by a few modest improvements. Substantial reductions in emissions of key pollutants are required both in East Tennessee and in

  15. DEVELOPMENT OF A VALIDATED MODEL FOR USE IN MINIMIZING NOx EMISSIONS AND MAXIMIZING CARBON UTILIZATION WHEN CO-FIRING BIOMASS WITH COAL

    Energy Technology Data Exchange (ETDEWEB)

    Larry G. Felix; P. Vann Bush; Stephen Niksa

    2003-04-30

    In full-scale boilers, the effect of biomass cofiring on NO{sub x} and unburned carbon (UBC) emissions has been found to be site-specific. Few sets of field data are comparable and no consistent database of information exists upon which cofiring fuel choice or injection system design can be based to assure that NOX emissions will be minimized and UBC be reduced. This report presents the results of a comprehensive project that generated an extensive set of pilot-scale test data that were used to validate a new predictive model for the cofiring of biomass and coal. All testing was performed at the 3.6 MMBtu/hr (1.75 MW{sub t}) Southern Company Services/Southern Research Institute Combustion Research Facility where a variety of burner configurations, coals, biomasses, and biomass injection schemes were utilized to generate a database of consistent, scalable, experimental results (422 separate test conditions). This database was then used to validate a new model for predicting NO{sub x} and UBC emissions from the cofiring of biomass and coal. This model is based on an Advanced Post-Processing (APP) technique that generates an equivalent network of idealized reactor elements from a conventional CFD simulation. The APP reactor network is a computational environment that allows for the incorporation of all relevant chemical reaction mechanisms and provides a new tool to quantify NOx and UBC emissions for any cofired combination of coal and biomass.

  16. Estimation of the Paris NOx emissions from mobile MAX-DOAS observations and CHIMERE model simulations during the MEGAPOLI campaign using the closed integral method

    Science.gov (United States)

    Shaiganfar, Reza; Beirle, Steffen; Denier van der Gon, Hugo; Jonkers, Sander; Kuenen, Jeroen; Petetin, Herve; Zhang, Qijie; Beekmann, Matthias; Wagner, Thomas

    2017-06-01

    We determined NOx emissions from Paris in summer 2009 and winter 2009/2010 by applying the closed integral method (CIM) to a large set of car multi-axis differential optical absorption spectroscopy (MAX-DOAS) measurements performed within the framework of the MEGAPOLI project (http://megapoli.dmi.dk/). MAX-DOAS measurements of the tropospheric NO2 vertical column density (VCD) were performed in large circles around Paris. From the combination of the observed NO2 VCDs with wind fields, the NO2 influx into and the outflux from the encircled area was determined. The difference between the influx and outflux represents the total emission. Compared to previous applications of the CIM, the large number of measurements during the MEGAPOLI campaign allowed the investigation of important aspects of the CIM. In particular, the applicability of the CIM under various atmospheric conditions could be tested. Another important advantage of the measurements during MEGAPOLI is that simultaneous atmospheric model simulations with a high spatial resolution (3 × 3 km2) are available for all days. Based on these model data, it was possible to test the consistency of the CIM and to derive information about favourable or non-favourable conditions for the application of the CIM. We found that in most situations the uncertainties and the variability in the wind data dominate the total error budget, which typically ranges between 30 and 50 %. Also, measurement gaps and uncertainties in the partitioning ratio between NO and NO2 are important error sources. Based on a consistency check, we deduced a set of criteria on whether measurement conditions are suitable or not for the application of the CIM. We also developed a method for the calculation of the total error budget of the derived NOx emissions. Typical errors are between ±30 and ±50 % for individual days (with one full circle around Paris). From the application of the CIM to car MAX-DOAS observations we derive daily average NOx

  17. Estimation of the Paris NOx emissions from mobile MAX-DOAS observations and CHIMERE model simulations during the MEGAPOLI campaign using the closed integral method

    Directory of Open Access Journals (Sweden)

    R. Shaiganfar

    2017-06-01

    Full Text Available We determined NOx emissions from Paris in summer 2009 and winter 2009/2010 by applying the closed integral method (CIM to a large set of car multi-axis differential optical absorption spectroscopy (MAX-DOAS measurements performed within the framework of the MEGAPOLI project (http://megapoli.dmi.dk/. MAX-DOAS measurements of the tropospheric NO2 vertical column density (VCD were performed in large circles around Paris. From the combination of the observed NO2 VCDs with wind fields, the NO2 influx into and the outflux from the encircled area was determined. The difference between the influx and outflux represents the total emission. Compared to previous applications of the CIM, the large number of measurements during the MEGAPOLI campaign allowed the investigation of important aspects of the CIM. In particular, the applicability of the CIM under various atmospheric conditions could be tested. Another important advantage of the measurements during MEGAPOLI is that simultaneous atmospheric model simulations with a high spatial resolution (3 × 3 km2 are available for all days. Based on these model data, it was possible to test the consistency of the CIM and to derive information about favourable or non-favourable conditions for the application of the CIM. We found that in most situations the uncertainties and the variability in the wind data dominate the total error budget, which typically ranges between 30 and 50 %. Also, measurement gaps and uncertainties in the partitioning ratio between NO and NO2 are important error sources. Based on a consistency check, we deduced a set of criteria on whether measurement conditions are suitable or not for the application of the CIM. We also developed a method for the calculation of the total error budget of the derived NOx emissions. Typical errors are between ±30 and ±50 % for individual days (with one full circle around Paris. From the application of the CIM to car MAX-DOAS observations we derive

  18. A method for evaluating spatially-resolved NOx emissions using Kalman filter inversion, direct sensitivities, and space-based NO2 observations

    Directory of Open Access Journals (Sweden)

    R. V. Martin

    2008-09-01

    Full Text Available An inverse modeling method was developed and tested for identifying possible biases in emission inventories using satellite observations. The relationships between emission inputs and modeled ambient concentrations were estimated using sensitivities calculated with the decoupled direct method in three dimensions (DDM-3D implemented within the framework of the Community Multiscale Air Quality (CMAQ regional model. As a case study to test the approach, the method was applied to regional ground-level NOx emissions in the southeastern United States as constrained by observations of NO2 column densities derived from the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY satellite instrument. A controlled "pseudodata" scenario with a known solution was used to establish that the methodology can achieve the correct solution, and the approach was then applied to a summer 2004 period where the satellite data are available. The results indicate that emissions biases differ in urban and rural areas of the southeast. The method suggested slight downward (less than 10% adjustment to urban emissions, while rural region results were found to be highly sensitive to NOx processes in the upper troposphere. As such, the bias in the rural areas is likely not solely due to biases in the ground-level emissions. It was found that CMAQ was unable to predict the significant level of NO2 in the upper troposphere that was observed during the NASA Intercontinental Chemical Transport Experiment (INTEX measurement campaign. The best correlation between satellite observations and modeled NO2 column densities, as well as comparison to ground-level observations of NO2, was obtained by performing the inverse while accounting for the significant presence of NO2 in the upper troposphere not captured by the regional model.

  19. North European Understanding of Zero Energy/Emission Buildings

    DEFF Research Database (Denmark)

    Marszal, Anna Joanna; Bourrelle, J. S.; Nieminen, J.

    2010-01-01

    countries are still to adopt a national definition for these types of buildings. This results often in more than one understanding of ZEBs in each country. This study provides a concise source of information on the north European understanding of zero energy/emission buildings. It puts forward a number......The worldwide CO2 emission mitigation efforts, the growing energy resource shortage and the fact that buildings are responsible for a large share of the world’s primary energy use drives research towards new building concepts, in particular Zero Energy/Emission Buildings (ZEBs). Unfortunately......, the lack of a common understanding for this new type of building results in most countries to have their own, unique approaches. This paper presents the northern (Danish, Finish, Norwegian and Swedish) understanding of ZEBs and gathers together information related to ZEBs in these countries. Generally, we...

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

    Energy Technology Data Exchange (ETDEWEB)

    Zanfir, Monica; Solunke, Rahul; Shah, Minish

    2012-06-01

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

  1. North European Understanding of Zero Energy/Emission Buildings

    DEFF Research Database (Denmark)

    Marszal, Anna Joanna; Bourrelle, Julien S.; Nieminen, Jyri

    2010-01-01

    countries are still to adopt a national definition for these types of buildings. This results often in more than one understanding of ZEBs in each country. This study provides a concise source of information on the north European understanding of zero energy/emission buildings. It puts forward a number......The worldwide CO2 emission mitigation efforts, the growing energy resource shortage and the fact that buildings are responsible for a large share of the world’s primary energy use drives research towards new building concepts, in particular Zero Energy/Emission Buildings (ZEBs). Unfortunately...... may observe a correlation between the zero energy/emission building approach adopted by a country and this particular country’s utility grid characteristics. Moreover, it is to be noted that the ZEB concept is not well defined at the national level in northern Europe and that all of the participating...

  2. Effectiveness of low emission zones: large scale analysis of changes in environmental NO2, NO and NOx concentrations in 17 German cities.

    Directory of Open Access Journals (Sweden)

    Peter Morfeld

    Full Text Available Low Emission Zones (LEZs are areas where the most polluting vehicles are restricted from entering. The effectiveness of LEZs to lower ambient exposures is under debate. This study focused on LEZs that restricted cars of Euro 1 standard without appropriate retrofitting systems from entering and estimated LEZ effects on NO2, NO, and NOx ( = NO2+NO.Continuous half-hour and diffuse sampler 4-week average NO2, NO, and NOx concentrations measured inside and outside LEZs in 17 German cities of 6 federal states (2005-2009 were analysed as matched quadruplets (two pairs of simultaneously measured index values inside LEZ and reference values outside LEZ, one pair measured before and one after introducing LEZs with time differences that equal multiples of 364 days by multiple linear and log-linear fixed-effects regression modelling (covariables: e.g., wind velocity, amount of precipitation, height of inversion base, school holidays, truck-free periods. Additionally, the continuous half-hour data was collapsed into 4-week averages and pooled with the diffuse sampler data to perform joint analysis.More than 3,000,000 quadruplets of continuous measurements (half-hour averages were identified at 38 index and 45 reference stations. Pooling with diffuse sampler data from 15 index and 10 reference stations lead to more than 4,000 quadruplets for joint analyses of 4-week averages. Mean LEZ effects on NO2, NO, and NOx concentrations (reductions were estimated to be at most -2 µg/m(3 (or -4%. The 4-week averages of NO2 concentrations at index stations after LEZ introduction were 55 µg/m(3 (median and mean values or 82 µg/m(3 (95th percentile.This is the first study investigating comprehensively the effectiveness of LEZs to reduce NO2, NO, and NOx concentrations controlling for most relevant potential confounders. Our analyses indicate that there is a statistically significant, but rather small reduction of NO2, NO, and NOx concentrations associated with LEZs.

  3. The impact of particulate matter (PM and nitric oxides (NOx on human health and an analysis of selected sources accounting for their emission in Poland

    Directory of Open Access Journals (Sweden)

    Jakub Krzeszowiak

    2016-10-01

    Full Text Available Introduction and objective: This paper is concerned with the harmful impact of nitric oxides (NOx and particulate matter (PM on humans. The objective was to determine which source of emission is the most urgent in terms of its reduction.Abbreviated description of the state of knowledge: In published epidemiological studies multiple notifications indicating the harmful impact of particulate matter on human health can be found. The harmful impact is underscored by the increase in the number of hospitalisations owing to diseases of respiratory and cardio-vascular systems, as well as by the rise in general fatality rate. The analysis of the PM impact on the human body is prompted by the fact that its detrimental effects are not clearly defined. Additionally, nitric oxides contribute to the increased number of exacerbations of respiratory disease and are a factor increasing susceptibility to development of local inflammation. Conclusions: The following study is meant to show that the air pollution which derives from vehicles (NOx and PM has a significant impact on human health. This applies particularly to residents of cities and big towns. This issue has gained special importance in Poland. According to the data from the Central Statistical Office, the increasing number of vehicles in use and their age lead to increased emission of the pollutants considered.

  4. A CONTROL-ORIENTED REAL-TIME SEMI-EMPIRICAL MODEL FOR THE PREDICTION OF NOX EMISSIONS IN DIESEL ENGINES

    OpenAIRE

    Fu, Lezhong

    2016-01-01

    Nowadays motor vehicle population increases rapidly, and it and this leads to serious energy and environmental problems. Hence, the environment and energy issues are becoming more and more important around the world. Many potential technologies have been presented and researched in universities, institutes and companies. Diesel engines are employed in Europe widely due to high thermal efficiency. The PCCI combustion concept has the potential of simultaneously reducing both NOx and particulate...

  5. 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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    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.

  6. Effects on NOx and SO2 Emissions during Co-Firing of Coal With Woody Biomass in Air Staging and Reburning

    Directory of Open Access Journals (Sweden)

    Nihad Hodžić

    2018-02-01

    Full Text Available Co-firing coal with different types of biomass is increasingly being applied in thermal power plants in Europe. The main motive for the use of biomass as the second fuel in coal-fired power plants is the reduction of CO2 emissions, and related financial benefits in accordance with the relevant international regulations and agreements. Likewise, the application of primary measures in the combustion chamber, which also includes air staging and/or reburning, results in a significant reduction in emission of polluting components of flue gases, in particular NOx emissions. In addition to being efficient and their application to new and future thermoblocks is practically unavoidable, their application and existing conventional combustion chamber does not require significant constructional interventions and is therefore relatively inexpensive. In this work results of experimental research of co-firing coals from Middle Bosnian basin with waste woody biomass are presented. Previously formed fuel test matrix is subjected to pulverized combustion under various temperatures and various technical and technological conditions. First of all it refers to the different mass ratio of fuel components in the mixture, the overall coefficient of excess air and to the application of air staging and/or reburning. Analysis of the emissions of components of the flue gases are presented and discussed. The impact of fuel composition and process temperature on the values of the emissions of components of the flue gas is determined. Additionally, it is shown that other primary measures in the combustion chamber are resulting in more or less positive effects in terms of reducing emissions of certain components of the flue gases into the environment. Thus, for example, the emission of NOx of 989 mg/ measured in conventional combustion, with the simultaneous application of air staging and reburning is reduced to 782 mg/, or by about 21%. The effects of the primary measures

  7. Nox NADPH oxidases and the endoplasmic reticulum.

    Science.gov (United States)

    Laurindo, Francisco R M; Araujo, Thaís L S; Abrahão, Thalita B

    2014-06-10

    Understanding isoform- and context-specific subcellular Nox reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase compartmentalization allows relevant functional inferences. This review addresses the interplay between Nox NADPH oxidases and the endoplasmic reticulum (ER), an increasingly evident player in redox pathophysiology given its role in redox protein folding and stress responses. Catalytic/regulatory transmembrane subunits are synthesized in the ER and their processing includes folding, N-glycosylation, heme insertion, p22phox heterodimerization, as shown for phagocyte Nox2. Dual oxidase (Duox) maturation also involves the regulation by ER-resident Duoxa2. The ER is the activation site for some isoforms, typically Nox4, but potentially other isoforms. Such location influences redox/Nox-mediated calcium signaling regulation via ER targets, such as sarcoendoplasmic reticulum calcium ATPase (SERCA). Growing evidence suggests that Noxes are integral signaling elements of the unfolded protein response during ER stress, with Nox4 playing a dual prosurvival/proapoptotic role in this setting, whereas Nox2 enhances proapoptotic signaling. ER chaperones such as protein disulfide isomerase (PDI) closely interact with Noxes. PDI supports growth factor-dependent Nox1 activation and mRNA expression, as well as migration in smooth muscle cells, and PDI overexpression induces acute spontaneous Nox activation. Mechanisms of PDI effects include possible support of complex formation and RhoGTPase activation. In phagocytes, PDI supports phagocytosis, Nox activation, and redox-dependent interactions with p47phox. Together, the results implicate PDI as possible Nox organizer. We propose that convergence between Noxes and ER may have evolutive roots given ER-related functional contexts, which paved Nox evolution, namely calcium signaling and pathogen killing. Overall, the interplay between Noxes and the ER may provide relevant insights in Nox-related (patho)physiology.

  8. Effects of Turbulence on Flame Structure and NOx Emission of Turbulent Jet Non-Premixed Flames in High-Temperature Air Combustion

    Science.gov (United States)

    Kobayashi, Hideaki; Oono, Ken; Cho, Eun-Seong; Hagiwara, Hirokazu; Ogami, Yasuhiro; Niioka, Takashi

    Turbulent jet non-premixed flame under the conditions of High Temperature Air Combustion (HiCOT) was investigated. Air diluted with nitrogen was preheated up to about 1300K. Propane was injected through a fuel tube parallel to the preheated airflow. LDV measurement of turbulence, CH-PLIF for reaction zone visualization, and NOx concentration measurements in the burnt gas were performed and the relations between these characteristics were examined. Results showed that turbulence intensity generated by perforated plate installed upstream of the fuel tube was high at high-temperature airflow due to high velocity compared with that at room temperature airflow when the flow rate was controlled to keep the excess air ratio constant regardless of preheating. The reaction zone represented by the CH-PLIF images still had a thin structure even in the HiCOT condition of oxygen concentration of 8vol.%. The flow turbulence in the combustion duct played a significant role in decreasing NOx emission. Due to turbulence, flame was broken and a bubble-like flame structure was generated, especially in the lifted flame cases, implying that the burning fuel lumps flow a considerable distance in air with a low oxygen concentration and generate uniform heat release profiles in HiCOT furnaces.

  9. Evaluation of NOx emission uncertainties based on car-MAX-DOAS observations and CHIMERE model simulations during the MEGAPOLI campaigns in Paris in Summer 2009 and Winter 2009/10

    Science.gov (United States)

    Shaiganfar, Reza; Petetin, Herve; Beirle, Steffen; Beekmann, Matthias; Wagner, Thomas

    2016-04-01

    Within the European project MEGAPOLI we performed two extensive car-MAX-DOAS campaigns around Paris in August 2009 and January/February 2010. The car-MAX-DOAS observations are conducted on circles with different radii around the city with the aim to quantify the NOx emissions from the area inside the circles. The method is based on the combination of the retrieved tropospheric NO2 column densities with wind fields. In this way the influx and the outflux can be calculated; the difference of both represents emissions from the encircled area. Since the car-MAX-DOAS observations are only sensitive to NO2, the derived NO2 emissions have to be upscaled to the total NOx (NO + NO2) emissions from megacity. Also corrections for the rather short lifetime of NOx have to be applied. In our study we investigate the uncertainty of the method with respect to different measurement parameters and wind conditions. For that purpose we make use of model simulations from the regional CHIMERE model. First we sample the modelled NO2 fields at the exact locations and times of the car-MAX-DOAS measurements. Second, we apply the method for the determination of the NOx emissions to this sampled model data. Third, we compare the derived emissions to the input emissions used in the model simulations. From the comparison we identify critical parameters for the application of our method and develop a method for the determination of the uncertainty of the derived emissions. Largest errors are found for situations with low wind speed and/or high variability of the wind speed or direction during the period of the measurements. Also gaps or road segments close to the citiy center cause larger errors. Finally, we apply the method to the car-MAX-DOAS observations and compare the derived emissions to existing emission inventories.

  10. Measurement of ethylene emission from Japanese red pine (Pinus densiflora) under field conditions in NOx-polluted areas

    International Nuclear Information System (INIS)

    Kume, A.; Nakatani, N.; Tsuboi, N.; Nakane, K.; Sakurai, N.; Nakagawa, N.; Sakugawa, H.

    2001-01-01

    Emission of ethylene from the needles of Japanese red pine, Pinus densiflora, was measured in air-polluted areas in Hiroshima, Japan. We applied a suitable protocol to determine the rate of ethylene emission from the excised needles. The influence of excision of needles on ethylene emission was not detected during the first 4 h of incubation at 20degC. Ethylene emissions were low in the unpolluted (Clean) areas regardless of the altitude or season. The emission of stress ethylene increased with the atmospheric NO 2 concentration, suggesting that atmospheric NO x or related substances induced the higher ethylene emission in the polluted areas (near urban and industrial areas). In all cases, 1-year-old needles emitted significantly larger amounts of ethylene than the current needles. Ethylene emission did not increase evenly in the polluted areas, but the frequency of trees emitting high ethylene increased. Therefore, threshold rates for the baseline ethylene emission were proposed. (Author)

  11. A Pilot-Scale Evaluation of a New Technology to Control NO(x) Emissions from Boilers at KSC: Hydrogen Peroxide Injection into Boiler Flue Gases Followed by Wet Scrubbing of Acid Gases

    Science.gov (United States)

    Cooper, C. David

    1997-01-01

    Emissions of nitrogen oxides NO(x) are a significant problem in the United States. NO(x) are formed in any combustion process, therefore it is not surprising that NO(x) are emitted from the boilers at KSC. Research at UCF has shown (in the laboratory) that injecting H2O2 into hot simulated flue gases can oxidize the NO and NO2 to their acid gas forms, HNO2 and HNO3, respectively. These acid gases are much more water soluble than their counterparts, and theoretically can be removed easily by wet scrubbing. This technology was of interest to NASA, both for their boilers at KSC, and for their combustion sources elsewhere. However, it was necessary to field test the technology and to provide pilot-scale data to aid in design of full-scale facilities. Hence this project was initiated in May of 1996.

  12. Experimental investigation of urea injection parameters influence on NOx emissions from blended biodiesel-fueled diesel engines.

    Science.gov (United States)

    Mehregan, Mina; Moghiman, Mohammad

    2018-02-01

    The present work submits an investigation about the effect of urea injection parameters on NO x emissions from a four-stroke four-cylinder diesel engine fueled with B20 blended biodiesel. An L 9 (3 4 ) Taguchi orthogonal array was used to design the test plan. The results reveal that increasing urea concentration leads to lower NO x emissions. Urea flow rate increment has the same influence on NO x emission. The same result is obtained by an increase in spray angle. Also, according to the analysis of variance (ANOVA), urea concentration and then urea flow rate are the most effective design parameters on NO x emissions, while spray angle and mixing length have less influence on this pollutant emission. Finally, since the result of confirmation test is in good agreement with the predicted value based on the Taguchi technique, the predictive capability of this method in the present study could be deduced.

  13. Ammonia-Free NOx Control System

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-03-31

    Research is being conducted under United States Department of Energy (DOE) Contract DE-FC26-03NT41865 to develop a new technology to achieve very low levels of NOx emissions from pulverized coal fired boiler systems by employing a novel system level integration between the PC combustion process and the catalytic NOx reduction with CO present in the combustion flue gas. The combustor design and operating conditions will be optimized to achieve atypical flue gas conditions. This approach will not only suppress NOx generation during combustion but also further reduce NOx over a downstream catalytic reactor that does not require addition of an external reductant, such as ammonia.

  14. Ammonia-Free NOx Control System

    Energy Technology Data Exchange (ETDEWEB)

    Song Wu; Zhen Fan; Andrew H. Seltzer

    2005-06-30

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

  15. Real world CO2 and NOx emissions from 149 Euro 5 and 6 diesel, gasoline and hybrid passenger cars.

    Science.gov (United States)

    O'Driscoll, Rosalind; Stettler, Marc E J; Molden, Nick; Oxley, Tim; ApSimon, Helen M

    2018-04-15

    In this study CO 2 and NO x emissions from 149 Euro 5 and 6 diesel, gasoline and hybrid passenger cars were compared using a Portable Emissions Measurement System (PEMS). The models sampled accounted for 56% of all passenger cars sold in Europe in 2016. We found gasoline vehicles had CO 2 emissions 13-66% higher than diesel. During urban driving, the average CO 2 emission factor was 210.5 (sd. 47) gkm -1 for gasoline and 170.2 (sd. 34) gkm -1 for diesel. Half the gasoline vehicles tested were Gasoline Direct Injection (GDI). Euro 6 GDI engines created by excessive NO x emissions from modern diesel vehicles. Replacing diesel with gasoline would incur a substantial CO 2 penalty, however greater uptake of hybrid vehicles would likely reduce both CO 2 and NO x emissions. Discrimination of vehicles on the basis of Euro standard is arbitrary and incentives should promote vehicles with the lowest real-world emissions of both NO x and CO 2 . Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Comparison of emission inventory and ambient concentration ratios of CO, NMOG, and NOx in California South Coast Air Basin

    International Nuclear Information System (INIS)

    Fujita, E.M.; Croes, B.E.; Bennett, C.L.; Lawson, D.R.; Lurmann, F.W.; Main, H.H.

    1992-01-01

    In the present study, the author performed a top-down validation of the reactive organic gas and carbon monoxide emission inventories for California's South Coast Air Basin by comparing speciation profiles for nonmethane organic gases (NMOG) and ratios of CO/NO x and NMOG/NO x derived from early-morning (0700 to 0800) ambient measurements taken during the 1987 Southern California Air Quality Study with the corresponding ratios and speciation profiles derived from day-specific, hourly, gridded emission inventories. Twenty separate comparisons were considered for each ratio, each representing a different combination of season, emission category, and spatial and temporal averaging of emissions. It was determined that the most appropriate comparison in summer was ambient pollutant ratios with ratios derived from morning on-road motrovehicle emission inventories, and in the fall, ambient ratios with ratios derived from overnight on-road motor vehicle emission inventories with some contribution from overnight stationary-source NO x emission inventories. From these comparisons, the ambient CO/CO x and NMOG/NO x ratios are about 1.5 and 2 to 2.5 times higher, respectively, than the corresponding inventory ratios. On the assumption that inventories of NO x emissions are reasonably correct, these results indicate that on-road motor vehicle CO and NMOG emissions are significantly underestimated. Comparisons of measured CO, NMOG, and NO x concentrations and CO/NO x and NMOG/NO x ratios with air quality model predictions obtained by the California Air Resources Board show similar differences

  17. ASSESSMENT OF CONTROL TECHNOLOGIES FOR REDUCING EMISSIONS OF SO2 AND NOX FROM EXISTING COAL-FIRED UTILITY BOILERS

    Science.gov (United States)

    The report reviews information and estimated costs on 15 emissioncontrol technology categories applicable to existing coal-fired electric utility boilers. he categories include passive controls such as least emission dispatching, conventional processes, and emerging technologies ...

  18. Possibilities of Simultaneous In-Cylinder Reduction of Soot and NOx Emissions for Diesel Engines with Direct Injection

    OpenAIRE

    Wagner, U.; Eckert, P.; Spicher, U.

    2008-01-01

    Up to now, diesel engines with direct fuel injection are the propulsion systems with the highest efficiency for mobile applications. Future targets in reducing CO2 -emissions with regard to global warming effects can be met with the help of these engines. A major disadvantage of diesel engines is the high soot and nitrogen oxide emissions which cannot be reduced completely with only engine measures today. The present paper describes two different possibilities for the sim...

  19. Fuel-based inventory of NOx and SO2 emissions from motor vehicles in the Hiroshima Prefecture, Japan

    International Nuclear Information System (INIS)

    Nurrohim, Agus; Sakugawa, Hiroshi

    2005-01-01

    In order to attain the 2010 target of reducing national greenhouse gases by 6% to the 1990 level, with reference to the Kyoto Protocol, the Government of Japan has planned and implemented some measures, as well as related policies. This paper discusses the possible impact of these measures on the nitrogen-oxide and sulfur-dioxide emissions from road vehicles in the Hiroshima Prefecture (ca. 3 million population). The number of road vehicles based on vehicle and fuel types in the Hiroshima Prefecture for 1990-2000 are presented, as well as projections for the years 2005 and 2010 using the Gompertz model. Three scenarios were developed to assess the emissions, referring to the possible achievement of related measures and policies as well as new vehicle technologies. Prediction results show that nitrogen-oxide emissions may be decreased from 14.7 kton in 1990 to 9.3 kton in 2010 if Japanese energy-policy and new vehicle developments are successfully implemented. If they are less successfully implemented, the emissions will decrease slightly to 14 kton, in which the decrease of emissions was mostly from gasoline vehicle. The emission of sulfur dioxide was projected to decrease from 1.2 kton in 1990 to within the range 0.45-0.49 kton by 2010, as a result of measures to reduce sulfur content in diesel oil

  20. Consequences of increased NOx emission to air during the handling of gas from the Haltenbanken Soer at Kaarstoe

    International Nuclear Information System (INIS)

    Guerreiro, Cristina

    1998-11-01

    This report discusses the consequences of increasing the emission to air of nitrogen oxides if landing facilities for North-Sea gas is developed at Kaarstoe, Norway. Three alternatives are considered. The pollution from such a facility comes in addition to the existing plant at Kaarstoe, the Aasgard terminal and the planned gas power station. The report considers concentrations in air, deposition to ground, impact on acidification of surface water and the impact of the natural environment. Concentrations in air have been calculated. The assessment of the deposition of nitrogen oxides to ground, the assessment of acidification of surface water and the assessment of the impact on flora and fauna are based on a consequence analysis for a gas power station at Kaarstoe. The influence of the development of the Kaarstoe plant on the local environment is largely determined by the amount of emissions and the tallness of the chimney. The regional impact is not very dependent on the emission conditions and the global impact is independent of the emission conditions and, to some extent, of the emission site

  1. Agriculture is a major source of NOx pollution in California

    Science.gov (United States)

    Almaraz, Maya; Bai, Edith; Wang, Chao; Trousdell, Justin; Conley, Stephen; Faloona, Ian; Houlton, Benjamin Z.

    2018-01-01

    Nitrogen oxides (NOx = NO + NO2) are a primary component of air pollution—a leading cause of premature death in humans and biodiversity declines worldwide. Although regulatory policies in California have successfully limited transportation sources of NOx pollution, several of the United States’ worst–air quality districts remain in rural regions of the state. Site-based findings suggest that NOx emissions from California’s agricultural soils could contribute to air quality issues; however, a statewide estimate is hitherto lacking. We show that agricultural soils are a dominant source of NOx pollution in California, with especially high soil NOx emissions from the state’s Central Valley region. We base our conclusion on two independent approaches: (i) a bottom-up spatial model of soil NOx emissions and (ii) top-down airborne observations of atmospheric NOx concentrations over the San Joaquin Valley. These approaches point to a large, overlooked NOx source from cropland soil, which is estimated to increase the NOx budget by 20 to 51%. These estimates are consistent with previous studies of point-scale measurements of NOx emissions from the soil. Our results highlight opportunities to limit NOx emissions from agriculture by investing in management practices that will bring co-benefits to the economy, ecosystems, and human health in rural areas of California. PMID:29399630

  2. NOx reduction and N2O emissions in a diesel engine exhaust using Fe-zeolite and vanadium based SCR catalysts

    International Nuclear Information System (INIS)

    Cho, Chong Pyo; Pyo, Young Dug; Jang, Jin Young; Kim, Gang Chul; Shin, Young Jin

    2017-01-01

    Highlights: • NO x reduction and N 2 O emission of urea-SCR catalysts with the oxidation precatalysts were investigated. • Fe-zeolite and V-based catalysts were noticeably affected by the NO 2 /NOx ratio. • Remarkable N 2 O formation was observed only for the Fe-zeolite catalyst. - Abstract: Among various approaches used to comply with strict diesel engine exhaust regulations, there is increasing interest in urea based selective catalytic reduction (SCR) as a NO x reduction technology, due to its high reduction and excellent fuel efficiencies. NO x reduction by SCR catalysts is affected by variations in the NO 2 /NO x ratio, caused by oxidation catalysts such as the diesel oxidation catalyst (DOC) and diesel particulate filter (DPF) installed in diesel engines. Recently, it has been reported that the greenhouse gas (GHG) variant N 2 O, which is a by-product of the NO x conversion process in the after-treatment system, will be subject to regulation. Using a real diesel engine installed with DOC and DPF, the NO x reduction and N 2 O emission performances of commonly used Fe-zeolite and V 2 O 5 -WO 3 /TiO 2 catalysts were investigated under various operating conditions. The exhaust of the diesel engine used in this study had a NO 2 /NO x ratio of over 50% for temperatures below 400 °C due to the oxidation catalysts, while the NO 2 /NO x ratio was significantly lower for temperatures above 400 °C. Under such conditions, it was found that the Fe-zeolite and V 2 O 5 -WO 3 /TiO 2 catalysts were noticeably affected by the NO 2 /NOx ratio and exhaust temperature. Although both catalysts showed satisfactory NO conversions, the V 2 O 5 -WO 3 /TiO 2 catalyst showed decreasing NO 2 conversion rates between 250 °C and 320 °C. The V 2 O 5 -WO 3 /TiO 2 catalyst exhibited NH 3 slip relatively frequently because of its low NH 3 storage capacity. For the Fe-zeolite catalyst, a significant increase in the amount of generated N 2 O was observed for high NO x conversion

  3. Co-benefits? Not always: Quantifying the negative effect of a CO2-reducing car taxation policy on NOx emissions

    International Nuclear Information System (INIS)

    Leinert, Stephan; Daly, Hannah; Hyde, Bernard; Gallachóir, Brian Ó

    2013-01-01

    With the current focus of policy action on climate change mitigation, it is important to investigate possible negative side effects of climate change policies on air pollutants. A 34% increase in CO 2 emissions from private cars in Ireland over the period 2000–2008 prompted a change in private car taxation in 2008 to incentivise the purchase of lower CO 2 emitting cars. The impact has been successful and the measure has accelerated the dieselisation of the car fleet. This however, raises an important question, namely how does the dieselisation of the car fleet affect NO x emissions? This paper combines two models to address this question, a car stock model to generate activity data (future composition and activity of Ireland's car stock) and the COPERT model to quantify the NO x emissions generated in the period 2008–2020. Previous analysis shows that the CO 2 taxation policy measure is anticipated to deliver a 7% reduction in private car related CO 2 emissions in 2020 compared with a baseline pre-tax scenario. The results here show that NO x emissions decrease in all scenarios, but a lesser degree of reduction is achieved due to dieselisation, with NO x emissions in the post-tax scenario 28% higher than the pre-tax scenario in 2020. - Highlights: • Irish car tax changed in 2008 to a CO 2 -graduated system. • Change successfully reduced the CO 2 intensity of new cars through dieselization. • However, this has negative consequences for air pollution. • Bottom-up model analyses pre-tax and post-tax NO x to 2020 using COPERT. • NO x projected to be 28% higher in 2020 compared with pre-tax scenario

  4. Portable nitrous oxide sensor for understanding agricultural and soil emissions

    Energy Technology Data Exchange (ETDEWEB)

    Stanton, Alan [Southwest Sciences, Inc., Santa Fe, NM (United States); Zondlo, Mark [Princeton Univ., NJ (United States); Gomez, Anthony [Southwest Sciences, Inc., Santa Fe, NM (United States); Pan, Da [Princeton Univ., NJ (United States)

    2017-02-27

    Nitrous oxide (N2O) is the third most important greenhouse gas (GHG,) with an atmospheric lifetime of ~114 years and a global warming impact ~300 times greater than that of carbon dioxide. The main cause of nitrous oxide’s atmospheric increase is anthropogenic emissions, and over 80% of the current global anthropogenic flux is related to agriculture, including associated land-use change. An accurate assessment of N2O emissions from agriculture is vital not only for understanding the global N2O balance and its impact on climate but also for designing crop systems with lower GHG emissions. Such assessments are currently hampered by the lack of instrumentation and methodologies to measure ecosystem-level fluxes at appropriate spatial and temporal scales. Southwest Sciences and Princeton University are developing and testing new open-path eddy covariance instrumentation for continuous and fast (10 Hz) measurement of nitrous oxide emissions. An important advance, now being implemented, is the use of new mid-infrared laser sources that enable the development of exceptionally low power (<10 W) compact instrumentation that can be used even in remote sites lacking in power. The instrumentation will transform the ability to measure and understand ecosystem-level nitrous oxide fluxes. The Phase II results included successful extended field testing of prototype flux instruments, based on quantum cascade lasers, in collaboration with Michigan State University. Results of these tests demonstrated a flux detection limit of 5 µg m-2 s-1 and showed excellent agreement and correlation with measurements using chamber techniques. Initial tests of an instrument using an interband cascade laser (ICL) were performed, verifying that an order of magnitude reduction in instrument power requirements can be realized. These results point toward future improvements and testing leading to introduction of a commercial open path instrument for N2O flux measurements that is truly portable and

  5. Biomass Suspension Combustion: Effect of Two-Stage Combustion on NOx Emissions in a Laboratory-Scale Swirl Burner

    DEFF Research Database (Denmark)

    Lin, Weigang; Jensen, Peter Arendt; Jensen, Anker Degn

    2009-01-01

    A systematic study was performed in a suspension fired 20 kW laboratory-scale swirl burner test rig for combustion of biomass and co-combustion of natural gas and biomass. The main focus is put on the effect of two-stage combustion on the NO emission, as well as its effect on the incomplete combu...

  6. Role of fuel additives on reduction of NOX emission from a diesel engine powered by camphor oil biofuel

    KAUST Repository

    Subramanian, Thiyagarajan

    2018-03-21

    The present study intends to explore the effect of the addition of fuel additives with camphor oil (CMO) on the characteristics of a twin-cylinder compression ignition (CI) engine. The lower viscosity and boiling point of CMO when compared to diesel could improve the fuel atomization, evaporation, and air/fuel mixing process. However, the lower cetane index of CMO limits its use as a drop in fuel for diesel in CI engine. In general, NO emission increases for less viscous and low cetane (LVLC) fuels due to pronounced premixed combustion phase. To improve the ignition characteristics and decrease NO emissions, fuel additives such as diglyme (DGE)—a cetane enhancer, cumene (CU)—an antioxidant, and eugenol (EU) and acetone (A)—bio-additives, are added 10% by volume with CMO. The engine used for the experimentation is a twin-cylinder tractor engine that runs at a constant speed of 1500 rpm. The engine was operated with diesel initially to attain warm-up condition, which facilitates the operation of neat CMO. At full load condition, brake thermal efficiency (BTE) for CMO is higher (29.6%) than that of diesel (28.1%), while NO emission is increased by 9.4%. With DGE10 (10% DGE + 90% CMO), the ignition characteristics of CMO are improved and BTE is increased to 31.7% at full load condition. With EU10 (10% EU + 90% CMO) and A10 (10% A + 90% CMO), NO emission is decreased by 24.6 and 17.8% when compared to diesel, while BTE is comparable to diesel. While HC and CO emission decreased for DGE10 and CU10, they increased for EU10 and A10 when compared to baseline diesel and CMO.

  7. Role of fuel additives on reduction of NOX emission from a diesel engine powered by camphor oil biofuel.

    Science.gov (United States)

    Subramanian, Thiyagarajan; Varuvel, Edwin Geo; Ganapathy, Saravanan; Vedharaj, S; Vallinayagam, R

    2018-03-21

    The present study intends to explore the effect of the addition of fuel additives with camphor oil (CMO) on the characteristics of a twin-cylinder compression ignition (CI) engine. The lower viscosity and boiling point of CMO when compared to diesel could improve the fuel atomization, evaporation, and air/fuel mixing process. However, the lower cetane index of CMO limits its use as a drop in fuel for diesel in CI engine. In general, NO X emission increases for less viscous and low cetane (LVLC) fuels due to pronounced premixed combustion phase. To improve the ignition characteristics and decrease NO X emissions, fuel additives such as diglyme (DGE)-a cetane enhancer, cumene (CU)-an antioxidant, and eugenol (EU) and acetone (A)-bio-additives, are added 10% by volume with CMO. The engine used for the experimentation is a twin-cylinder tractor engine that runs at a constant speed of 1500 rpm. The engine was operated with diesel initially to attain warm-up condition, which facilitates the operation of neat CMO. At full load condition, brake thermal efficiency (BTE) for CMO is higher (29.6%) than that of diesel (28.1%), while NO X emission is increased by 9.4%. With DGE10 (10% DGE + 90% CMO), the ignition characteristics of CMO are improved and BTE is increased to 31.7% at full load condition. With EU10 (10% EU + 90% CMO) and A10 (10% A + 90% CMO), NO X emission is decreased by 24.6 and 17.8% when compared to diesel, while BTE is comparable to diesel. While HC and CO emission decreased for DGE10 and CU10, they increased for EU10 and A10 when compared to baseline diesel and CMO.

  8. Development and improvement of historical emission inventory in Asia

    Science.gov (United States)

    Kurokawa, J. I.; Yumimoto, K.; Itahashi, S.; Maki, T.; Nagashima, T.; Ohara, T.

    2016-12-01

    Due to the rapid growth of economy and population, Asia becomes the largest emitter regions of air pollutants and greenhouse gases in the world. To tackle this problem, it is essential to understand the current status and past trend and to estimate effectiveness of mitigation measures using monitoring data, air quality and climate models, and emission inventories. We developed a historical emission inventory in Asia for 1950-2010 base on Regional Emission Inventory in ASia (REAS) version 2. In these 6 decades, emissions of all species in Asia showed remarkable increases. Recently, the largest emitter country in Asia is China. However, in 1960s, Japan is the largest emitter country for SO2 till about 1970 and NOx till about 1980, respectively. We surveyed effectiveness of abatement measures on NOx emissions in Japan and China. In Japan, the largest effective mitigation measure is regulation for motor vehicles. In 2010, reduced amounts of NOx emissions were estimated to be 2.7 time larger than actual emissions. For China, until 2010, the most effective mitigation measure is low-NOx burner installed in power plants. Regulation of motor vehicles also assumed to reduce NOx emissions from road transport by 40% compared to those without regulations in 2010. We roughly expanded the period of NOx emissions in China and Japan till 2012 and trend between 2008 and 2012 were compared with top-down emissions estimated using inverse modeling technique and satellite observations. Compared to top-down emissions, trends of the bottom-up emissions in China (Japan) overestimated increased (decreased) ratios in 2008-2012. For China, our emissions seem to underestimate the penetration rates of FGD for NOx installed in power plants. On the other hand, decreased rates of NOx emission factors for road vehicles in Japan might be overestimated in our emissions. These differences will be reconsidered to update our bottom-up emission inventory.

  9. Basic understanding of the lanthanide related upconversion emissions

    Science.gov (United States)

    Dong, Hao; Sun, Ling-Dong; Yan, Chun-Hua

    2013-06-01

    With abundant energy levels of 4f electron configurations, trivalent lanthanide ions (Ln3+) are endowed with unique and fascinating luminescent properties. Inheriting the native transition behaviour of the lanthanide ions, Ln3+ based nanomaterials have aroused great interest for a wide range of applications, including lighting and displays, optical fibers and amplifiers, responsive luminescent stains for biomedical analysis, in vivo and in vitro imaging, and enhancement for silicon solar cell devices. It should be noted that the application depends completely on the corresponding luminescent behaviour. To deepen the understanding of the luminescent mechanism is important for the developing of the field and the design of new Ln3+ based luminescent materials toward applications. In this review, we focused mainly on the recent developments on upconversion (UC) emission studies. Firstly, the emphasis was put on the introduction of basic luminescent properties of Ln3+ with f-f transitions, and then the corresponding mechanisms and properties of UC emission were discussed in detail, the potential researches with respect to UC mechanisms and properties were finally outlined.

  10. DEVELOPMENT OF A VALIDATED MODEL FOR USE IN MINIMIZING NOx EMISSIONS AND MAXIMIZING CARBON UTILIZATION WHEN CO-FIRING BIOMASS WITH COAL

    Energy Technology Data Exchange (ETDEWEB)

    Larry G. Felix; P. Vann Bush

    2002-10-26

    This is the eighth Quarterly Technical Report for DOE Cooperative Agreement No. DE-FC26-00NT40895. A statement of the project objectives is included in the Introduction of this report. The final biomass co-firing test burn was conducted during this quarter. In this test (Test 14), up to 20% by weight dry switchgrass was comilled with Jim Walters No.7 mine coal and injected through the single-register burner. Jim Walters No.7 coal is a low-volatility, low-sulfur ({approx}0.7% S) Eastern bituminous coal. The results of this test are presented in this quarterly report. Progress has continued to be made in implementing a modeling approach to combine reaction times and temperature distributions from computational fluid dynamic models of the pilot-scale combustion furnace with char burnout and chemical reaction kinetics to predict NO{sub x} emissions and unburned carbon levels in the furnace exhaust. The REI Configurable Fireside Simulator (CFS) is now in regular use. Presently, the CFS is being used to generate CFD calculations for completed tests with Powder River Basin coal and low-volatility (Jim Walters No.7 Mine) coal. Niksa Energy Associates will use the results of these CFD simulations to complete their validation of the NOx/LOI predictive model. Work has started on the project final report.

  11. Decreased NOx emissions by use of selective catalytic reduction on a gas turbine in the food-processing sector; Reduction des emissions de NOx par l'application de la reduction catalytique selective a une turbine a gaz dans le secteur de l'agro-alimentaire

    Energy Technology Data Exchange (ETDEWEB)

    Van Esch, F.A.J. [Cerestar Benelux B.V., Sas van Gent (Netherlands)

    2001-07-01

    Cerestar is a company of Eridania Beghin-Say, and manufactures starches and starch derivatives. Its activities are controlled from Paris, France, with sales offices and production facilities located throughout the world. Eridania Beghin-Say is one of the leading companies in the processing of agricultural raw materials into food products such as sugar, starch and derivatives of starch, oils, vegetable proteins and lecithin, consumer products and animal feed. The largest Cerestar plant in Europe is located in Sas van Gent, The Netherlands. Different starches, starch derivatives and glucoses are produced from the raw materials corn and wheat. Cerestar has own cogeneration plants for the production of steam and electricity. This year, the capacity of the plant was doubled, by the construction of a new wheat plant. Together with the wheat plant, a third cogeneration plant was built, with NOx emissions much below the legal limits. (authors)

  12. Sustained Low Temperature NOx Reduction

    Energy Technology Data Exchange (ETDEWEB)

    Zha, Yuhui

    2017-04-05

    Increasing regulatory, environmental, and customer pressure in recent years led to substantial improvements in the fuel efficiency of diesel engines, including the remarkable breakthroughs demonstrated through the Super Truck program supported by the U.S. Department of Energy (DOE). On the other hand, these improvements have translated into a reduction of exhaust gas temperatures, thus further complicating the task of controlling NOx emissions, especially in low power duty cycles. The need for improved NOx conversion over these low temperature duty cycles is also observed as requirements tighten with in-use emissions testing. Sustained NOx reduction at low temperatures, especially in the 150-200oC range, shares some similarities with the more commonly discussed cold-start challenge, however poses a number of additional and distinct technical problems. In this project we set a bold target of achieving and maintaining a 90% NOx conversion at the SCR catalyst inlet temperature of 150oC. The project is intended to push the boundaries of the existing technologies, while staying within the realm of realistic future practical implementation. In order to meet the resulting challenges at the levels of catalyst fundamentals, system components, and system integration, Cummins has partnered with the DOE, Johnson Matthey, and Pacific Northwest National Lab and initiated the Sustained Low-Temperature NOx Reduction program at the beginning of 2015. Through this collaboration, we are exploring catalyst formulations and catalyst architectures with enhanced catalytic activity at 150°C; opportunities to approach the desirable ratio of NO and NO2 in the SCR feed gas; options for robust low-temperature reductant delivery; and the requirements for overall system integration. The program is expected to deliver an on-engine demonstration of the technical solution and an assessment of its commercial potential. In the SAE meeting, we will share the initial performance data on engine to

  13. Control of SO2 and NOx emissions from fossil fuel-fired power plants: Research and practice of TPRI

    International Nuclear Information System (INIS)

    Ming-Chuan Zhang.

    1993-01-01

    The generation of electric power in China has been dominated by coal for many years. By the end of 1990, total installed generating capacity reached 135 GW, of which fossil fuel-fired plants accounted for 74 percent. The total electricity generated reached 615 TWh, with fossil fuels accounting for 80.5 percent. About 276 million tons of raw coal are consumed in these fossil fuel-burning units per year, accounting for about 25 percent of the total output of the country. According to the government, by the year 2000, the total installed capacity of Chinese power systems should be at least 240 GW, of which fossil fuels will account for about 77 percent. The coal required for power generation will increase to about 530 million tons per year, accounting for about 38 percent of the total coal output. So, it is obvious that coal consumed in coal-fired power plants occupies a very important place in the national fuel balance. The current environmental protection standards, which are based on ground-level concentrations of pollutants, do not effectively lead to the control of pollution emission concentrations or total SO 2 emissions. Due to the practical limitations of the Chinese economy, there is a limited capability to introduce advanced sulfur emission control technologies. Thus, except for the two 360 MW units imported from Japan for the Luohuang Power Plant in Shichuan province, all the other fossil fuel-fired units have not yet adopted any kind of SO 2 removal measures. The Luohuang units are equipped with Mitsubishi limestone flue gas desulfurization systems. Because of the lack of effective pollution control technologies, large areas of the country have been seriously polluted by SO 2 , and some of them even by acid rain

  14. A novel least squares support vector machine ensemble model for NOx emission prediction of a coal-fired boiler

    International Nuclear Information System (INIS)

    Lv, You; Liu, Jizhen; Yang, Tingting; Zeng, Deliang

    2013-01-01

    Real operation data of power plants are inclined to be concentrated in some local areas because of the operators’ habits and control system design. In this paper, a novel least squares support vector machine (LSSVM)-based ensemble learning paradigm is proposed to predict NO x emission of a coal-fired boiler using real operation data. In view of the plant data characteristics, a soft fuzzy c-means cluster algorithm is proposed to decompose the original data and guarantee the diversity of individual learners. Subsequently the base LSSVM is trained in each individual subset to solve the subtask. Finally, partial least squares (PLS) is applied as the combination strategy to eliminate the collinear and redundant information of the base learners. Considering that the fuzzy membership also has an effect on the ensemble output, the membership degree is added as one of the variables of the combiner. The single LSSVM and other ensemble models using different decomposition and combination strategies are also established to make a comparison. The result shows that the new soft FCM-LSSVM-PLS ensemble method can predict NO x emission accurately. Besides, because of the divide and conquer frame, the total time consumed in the searching the parameters and training also decreases evidently. - Highlights: • A novel LSSVM ensemble model to predict NO x emissions is presented. • LSSVM is used as the base learner and PLS is employed as the combiner. • The model is applied to process data from a 660 MW coal-fired boiler. • The generalization ability of the model is enhanced. • The time consuming in training and searching the parameters decreases sharply

  15. 40 CFR 1065.670 - NOX intake-air humidity and temperature corrections.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false NOX intake-air humidity and... NOX intake-air humidity and temperature corrections. See the standard-setting part to determine if you may correct NOX emissions for the effects of intake-air humidity or temperature. Use the NOX intake...

  16. A methodology for the economic assessment of material damage caused by SO2 and NOx emissions in Europe

    International Nuclear Information System (INIS)

    Mayerhofer, P.; Weltschev, M.; Trukenmueller, A.; Friedrich, R.

    1995-01-01

    Damage to materials causes high economic losses in Europe. A large part of this damage can be attributed to the emissions caused by the energy and the transport sector. In the paper, the procedure for the economic assessment of material damages caused by SO 2 and NO x emissions in Europe is described. Model and data requirements are outlined, and gaps and uncertainties of the quantification are discussed. Two types of results are presented. First, the marginal (additional) costs of damage to material caused by an additional power plant are assessed. The analysis covers plants with different technologies. Results for the fossil power plants are in the range of 0.0062 to 0.12 mECU/kWh. In addition, the total economic material damage due to the present air pollution was assessed. It is in the range of 2.9 to 5.3 x 10 9 ECU/year. However, the analysis has many uncertainties. Most noteworthy are the material inventories and partially the damage functions and input data. 15 refs., 1 fig., 1 tab

  17. Effects of NOx and SO2 on the secondary organic aerosol formation from photooxidation of α-pinene and limonene

    Science.gov (United States)

    Zhao, Defeng; Schmitt, Sebastian H.; Wang, Mingjin; Acir, Ismail-Hakki; Tillmann, Ralf; Tan, Zhaofeng; Novelli, Anna; Fuchs, Hendrik; Pullinen, Iida; Wegener, Robert; Rohrer, Franz; Wildt, Jürgen; Kiendler-Scharr, Astrid; Wahner, Andreas; Mentel, Thomas F.

    2018-02-01

    Anthropogenic emissions such as NOx and SO2 influence the biogenic secondary organic aerosol (SOA) formation, but detailed mechanisms and effects are still elusive. We studied the effects of NOx and SO2 on the SOA formation from the photooxidation of α-pinene and limonene at ambient relevant NOx and SO2 concentrations (NOx: biogenic volatile organic compounds (VOCs) with anthropogenic emissions.

  18. Application of commercial sensor manufacturing methods for NOx/NH3 mixed potential sensors for emissions control

    Energy Technology Data Exchange (ETDEWEB)

    Brosha, Eric L [Los Alamos National Laboratory; Mukundan, Rangachary [Los Alamos National Laboratory; Nelson, Mark A [Los Alamos National Laboratory; Sekhar, Praveen [Los Alamos National Laboratory; Williamson, Todd [Los Alamos National Laboratory; Garzon, Fernando H [Los Alamos National Laboratory

    2009-01-01

    The purpose of this research effort is to develop a low cost on-board Nitrogen Oxide (NO{sub x})/Ammonia (NH{sub 3}) sensor that can not only be used for emissions control but has the potential to improve efficiency through better monitoring of the combustion process and feedback control in both vehicle and stationary systems. Over the past decade, Los AJamos National Laboratory (LANL) has developed a unique class of electrochemical gas sensors for the detection of carbon monoxide, hydrocarbons, hydrogen and nitrogen oxides. These sensors are based on the mixed-potential phenomenon and are a modification of the existing automotive lambda (oxygen) sensor and have the potential to meet the stringent sensitivity, selectivity and stability requirements of an on-board emissions/engine control sensor system. The current state of the art LANL technology is based on the stabilization of the electrochemical interfaces and relies on an externally heated, hand-made, tape cast device. We are now poised to apply our patented sensing principles in a mass production sensor platform that is more suitable for real world engine-out testing such as on dynamometers for vehicle applications and for exhaust-out testing in heavy boilers/SCR systems in power plants. In this present work, our goal is to advance towards commercialization of this technology by packaging the unique LANL sensor design in a standard automotive sensor-type platform. This work is being performed with the help of a leading US technical ceramics firm, utilizing commercial manufacturing techniques. Initial tape cast platforms with screen printed metal oxide and Pt sensor electrodes have shown promising results but also clearly show the need for us to optimize the electrode and electrolyte compositions/morphologies and interfaces of these devices in order to demonstrate a sensitive, selective, and stable NO{sub x} sensor. Our previous methods and routes to preparing stable and reproducible mixed potential sensors

  19. NOx, FINE PARTICLE AND TOXIC METAL EMISSIONS FROM THE COMBUSTION OF SEWAGE SLUDGE/COAL MIXTURES: A SYSTEMATIC ASSESSMENT

    Energy Technology Data Exchange (ETDEWEB)

    Jost O.L. Wendt

    2001-05-04

    This research project focuses on pollutants from the combustion of mixtures of dried municipal sewage sludge (MSS) and coal. The objective is to determine the relationship between (1) fraction sludge in the sludge/coal mixture, and (2) combustion conditions on (a) NO{sub x} concentrations in the exhaust, (b) the size segregated fine and ultra-fine particle composition in the exhaust, and (c) the partitioning of toxic metals between vapor and condenses phases, within the process. To this end we shall use an existing 17kW downflow laboratory combustor, available with coal and sludge feed capabilities. The proposed study will be conducted in concert with an existing ongoing research on toxic metal partitioning mechanisms for very well characterized pulverized coals alone. Both high NO{sub x} and low NO{sub x} combustion conditions will be investigated (unstaged and staged combustion). The proposed work uses existing analytical and experimental facilities and draws on 20 years of research on NO{sub x} and fine particles that has been funded by DOE in this laboratory. Four barrels of dried sewage sludge are currently in the laboratory. Insofar as possible pertinent mechanisms will be elucidated. Tradeoffs between CO{sub 2} control, NO{sub x} control, and inorganic fine particle and toxic metal emissions will be determined.

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

    Directory of Open Access Journals (Sweden)

    Rankovic N.

    2013-09-01

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

  1. Influence of staged-air on airflow, combustion characteristics and NO(x) emissions of a down-fired pulverized-coal 300 MW(e) utility boiler with direct flow split burners.

    Science.gov (United States)

    Li, Zhengqi; Kuang, Min; Zhang, Jia; Han, Yunfeng; Zhu, Qunyi; Yang, Lianjie; Kong, Weiguang

    2010-02-01

    Cold airflow experiments were conducted to investigate the aerodynamic field in a small-scale furnace of a down-fired pulverized-coal 300 MW(e) utility boiler arranged with direct flow split burners enriched by cyclones. By increasing the staged-air ratio, a deflected flow field appeared in the lower furnace; larger staged-air ratios produced larger deflections. Industrial-sized experiments on a full-scale boiler were also performed at different staged-air damper openings with measurements taken of gas temperatures in the burner region and near the right-side wall, wall heat fluxes, and gas components (O(2), CO, and NO(x)) in the near-wall region. Combustion was unstable at staged-air damper openings below 30%. For openings of 30% and 40%, late ignition of the pulverized coal developed and large differences arose in gas temperatures and heat fluxes between the regions near the front and rear walls. In conjunction, carbon content in the fly ash was high and boiler efficiency was low with high NO(x) emission above 1200 mg/m(3) (at 6% O(2) dry). For fully open dampers, differences in gas temperatures and heat fluxes, carbon in fly ash and NO(x) emission decreased yielding an increase in boiler efficiency. The optimal setting is fully open staged-air dampers.

  2. Xonon combustion system, 2,5 p.p.m NOx for gas turbines; Le processus de combustion Xonon limite les emissions des turbines a gaz a 2,5 p.p.m

    Energy Technology Data Exchange (ETDEWEB)

    Solt, Ch. [Catalytica Energy Systems Inc., California (United States)

    2001-07-01

    A gas turbine operates by compressing incoming air, combining it with fuel, and combusting the mixture. The combustion process releases the fuel's energy, forming hot gases that power the turbine. In conventional combustion systems, a flame is used to combust the fuel. The temperature required to sustain a stable flame is significantly higher than the temperature at which the gas turbine is designed to operate. This excessive temperature causes the nitrogen and oxygen in the air to react, forming nitrogen oxides (NOx), a major contributor to air pollution. We have developed Xonon{sup TM} Cool Combustion, a catalytic technology that combusts fuel flamelessly. This process releases the same amount of energy as flame-based combustion systems but at a lower temperature. Importantly, this lower temperature is below the threshold at which NOx is formed. The Xonon combustion system is the only operating catalytic combustion system demonstrated to achieve near-zero emissions. The Xonon combustion system is a pollution prevention technology that has been proven to limit emissions of NOx to less than 2.5 parts per million (ppm) without compromising the performance of the gas turbine engine. (author)

  3. NOx, FINE PARTICLE AND TOXIC METAL EMISSIONS FROM THE COMBUSTION OF SEWAGE SLUDGE/COAL MIXTURES: A SYSTEMATIC ASSESSMENT

    Energy Technology Data Exchange (ETDEWEB)

    Jost O.L. Wendt

    2002-02-05

    This research project focuses on pollutants from the combustion of mixtures of dried municipal sewage sludge (MSS) and coal. The objective is to determine the relationship between (1) fraction sludge in the sludge/coal mixture, and (2) combustion conditions on (a) NO{sub x} concentrations in the exhaust, (b) the size segregated fine and ultra-fine particle composition in the exhaust, and (c) the partitioning of toxic metals between vapor and condenses phases, within the process. To this end work is progress using an existing 17kW downflow laboratory combustor, available with coal and sludge feed capabilities. The proposed study will be conducted in concert with an existing ongoing research on toxic metal partitioning mechanisms for very well characterized pulverized coals alone. Both high NO{sub x} and low NO{sub x} combustion conditions will be investigated (unstaged and staged combustion). The proposed work uses existing analytical and experimental facilities and draws on 20 years of research on NO{sub x} and fine particles that has been funded by DOE in this laboratory. Four barrels of dried sewage sludge are currently in the laboratory. Insofar as possible pertinent mechanisms will be elucidated. Tradeoffs between CO{sub 2} control, NO{sub x} control, and inorganic fine particle and toxic metal emissions will be determined. Progress in the Sixth Quarter (January 1, 2002 through March 31, 2002) was slow because of slagging problems in the combustor. These required the combustor to be rebuilt, a job that is not yet complete. A paper describing our results heretofore has been accepted by the Journal Environmental Science and Technology.

  4. ASCR{trademark}: lower NOx removal costs without sacrificing performance

    Energy Technology Data Exchange (ETDEWEB)

    Bible, S.; Rummenhohl, V.; Siebeking, M.; Thomas, R.; Triece, C. [Fuel Tech (United States)

    2011-05-15

    With recent regulatory initiatives, the new Industrial Emissions Directive in Europe, and new rules being proposed by EPA in the USA, the question for power plants is now whether they will be required to reduce NOx emissions in the future to stay in operation, but when. What is needed is a low-capital-cost but high-performance NOx removal technology. 7 figs.

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

    NARCIS (Netherlands)

    Maas, van der P.M.F.

    2005-01-01

    The emission of nitrogen oxides (NOx) to the atmosphere is a major environmental problem. To abate NOx emissions from industrial flue gases, to date, mainly chemical processes like selective catalytic reduction (SCR) are applied. All these processes require high temperatures (>300 °C) and

  6. Influência do combustível (diesel e biodiesel e das características da frota de veículos do transporte coletivo de Curitiba, Paraná, nas emissões de NOx

    Directory of Open Access Journals (Sweden)

    Wellington Ferreira Ribas

    Full Text Available RESUMO: O sistema de transporte coletivo da cidade de Curitiba, no Paraná, é reconhecido pelas suas soluções inovadoras e modelo para o Brasil. Neste trabalho foi analisada a influência do combustível (diesel e biodiesel e das condições da frota de veículos do transporte coletivo de Curitiba nas emissões de NOx, e essa é uma iniciativa pioneira. Foram selecionados 188 veículos (9,7% do total com motores de 7 a 12 L, denominados B7R, B10M, B12M e B215RH, e foram realizadas medições de NO e NO2 na saída dos escapamentos. Com relação ao tipo de combustível, as emissões de NO e NO2 para o biodiesel (B100 foram, respectivamente, 37 e 26% superiores aos valores observados com o combustível diesel (S10. Comparando motores B12M com até 3 e 10 anos de operação, as emissões médias de NOx foram próximas de 40% maior. Assim, foi possível observar que os veículos a biodiesel tiveram maior emissão de NOx quando comparados com veículos a diesel, em condições similares de operação e tempo de uso do motor. Entretanto, embora o uso de biodiesel traga vantagens ambientais, como energia renovável, novas tecnologias e dispositivos devem ser desenvolvidos para controlar emissões de NO e NO2 em motores que utilizam esse tipo de combustível. Para trabalhos futuros, os autores recomendam testes em dinamômetro, para simular emissões de NOx em motores a diesel e biodiesel em diferentes condições de carga e regime de rotação do motor.

  7. SELECTIVE NOx RECIRCULATION FOR STATIONARY LEAN-BURN NATURAL GAS ENGINES

    Energy Technology Data Exchange (ETDEWEB)

    Nigel Clark; Gregory Thompson; Richard Atkinson; Chamila Tissera; Matt Swartz; Emre Tatli; Ramprabhu Vellaisamy

    2005-01-01

    The research program conducted at the West Virginia University Engine and Emissions Research Laboratory (EERL) is working towards the verification and optimization of an approach to remove nitric oxides from the exhaust gas of lean burn natural gas engines. This project was sponsored by the US Department of Energy, National Energy Technology Laboratory (NETL) under contract number: DE-FC26-02NT41608. Selective NOx Recirculation (SNR) involves three main steps. First, NOx is adsorbed from the exhaust stream, followed by periodic desorption from the aftertreatment medium. Finally the desorbed NOx is passed back into the intake air stream and fed into the engine, where a percentage of the NOx is decomposed. This reporting period focuses on the NOx decomposition capability in the combustion process. Although researchers have demonstrated NOx reduction with SNR in other contexts, the proposed program is needed to further understand the process as it applies to lean burn natural gas engines. SNR is in support of the Department of Energy goal of enabling future use of environmentally acceptable reciprocating natural gas engines through NOx reduction under 0.1 g/bhp-hr. The study of decomposition of oxides of nitrogen (NOx) during combustion in the cylinder was conducted on a 1993 Cummins L10G 240 hp lean burn natural gas engine. The engine was operated at different air/fuel ratios, and at a speed of 800 rpm to mimic a larger bore engine. A full scale dilution tunnel and analyzers capable of measuring NOx, CO{sub 2}, CO, HC concentrations were used to characterize the exhaust gas. Commercially available nitric oxide (NO) was used to mimic the NOx stream from the desorption process through a mass flow controller and an injection nozzle. The same quantity of NOx was injected into the intake and exhaust line of the engine for 20 seconds at various steady state engine operating points. NOx decomposition rates were obtained by averaging the peak values at each set point minus

  8. Effect of exhaust gases of Exhaust Gas Recirculation (EGR) coupling lean-burn gasoline engine on NOx purification of Lean NOx trap (LNT)

    Science.gov (United States)

    Liu, Lei; Li, Zhijun; Liu, Shiyu; Shen, Boxi

    2017-03-01

    Based on pervious experimental research on the application of Exhaust Gas Recirculation (EGR) and Lean NOx Trap (LNT) with its effects on NOx emission control and secondary development of CHEMKIN software, an integrated NOx purification chemical kinetics mechanism including NOx adsorption, NOx desorption and NOx reduction process of LNT was created based on actual exhaust gases of the lean-burn gasoline engine. The effect of exhaust gases on NOx deterioration of LNT was investigated by modifying H2, O2 and overlap phase in mechanism of NOx desorption and NOx reduction process. Research found that the inlet temperature of LNT around 300 °C possesses the best NOx adsorption performance compared with 200 °C and 400 °C. Pt plays an import role in the process of NOx adsorption and NOx reduction. The reductive capability order of complex compound between Pt, and H2, CO and HC is Pt-H2>Pt-CO>Pt-C3H6. Both CO2 and H2O(g) could deteriorate NOx purification of LNT. The deterioration caused by H2O(g) is not significant as CO2 but harder to be regenerated. O2 could be beneficial to the NOx adsorption process, but it also could weaken the reductive atmosphere in the process of NOx desorption and NOx reduction.

  9. Updated analysis of Denmark's possibilities of reducing NO{sub X} emissions; En opdateret analyse af Danmarks muligheder for at reducere emissionerne af NOx

    Energy Technology Data Exchange (ETDEWEB)

    COWI A/S, Kgs. Lyngby (Denmark)

    2009-07-01

    where assumptions are changed to show their influence on the results. The analysis show that the measures are robust to changes in interest rates and in the prices of electricity, gas and oil. However, if the investments are carried out at lower costs, four more measures would give a welfare-economic surplus. If the damage costs of emissions are lowered, fewer measures will give a welfare-economic surplus. Compared to the analysis from 2006, fewer measures will now give a welfareeconomic surplus, due to a lower damage cost of emissions. However better controls for gas engines at combined heat and power plants (CHP) and replacement to low-NOx burners at light oil fuel kettles in industry do still give a welfare-economic surplus. Moreover, replacement to low-NO{sub x} burners at light oil fuel kettles in CHP is now also a cost effective measure. Besides, their might be a potential for cost effective NO{sub x} reductions by optimising SNCR in waste incineration installations. (author)

  10. DEVELOPING A BETTER UNDERSTANDING OF REAL-WORLD AUTOMOBILE EMISSIONS

    Science.gov (United States)

    Emission inventories are needed by EPA for air dispersion modeling, regional strategy development, regulation setting, air toxics risk assessment, and trend tracking. Therefore, it is extremely important that inventories be accurate and be updated frequently. The development an...

  11. Understanding aerospace composite components' supply chain carbon emissions

    OpenAIRE

    Chua, Mang Hann; Smyth, Beatrice M.; Murphy, Adrian; Butterfield, Joseph

    2015-01-01

    This paper examines a large structural component and its supply chain. The component is representative of that used in the production of civil transport aircraft and is manufactured from carbon fibre epoxy resin prepreg, using traditional hand layup and autoclave cure. Life cycle assessment (LCA) is used to predict the component’s production carbon emissions. The results determine the distribution of carbon emissions within the supply chain, identifying the dominant production processes as ca...

  12. NOx Solutions for Biodiesel: Final Report; Report 6 in a Series of 6

    Energy Technology Data Exchange (ETDEWEB)

    McCormick, R. L.; Alvarez, J. R.; Graboski, M. S.

    2003-02-01

    A number of studies have shown substantial particulate matter (PM) reductions for biodiesel, but also a significant increase in nitrogen oxides (NOx) emissions. This study examines a number of approaches for NOx reduction from biodiesel.

  13. OXYGEN ENHANCED COMBUSTION FOR NOx CONTROL

    Energy Technology Data Exchange (ETDEWEB)

    David R. Thompson; Lawrence E. Bool; Jack C. Chen

    2004-04-01

    Conventional wisdom says adding oxygen to a combustion system enhances product throughput, system efficiency, and, unless special care is taken, increases NOx emissions. This increase in NOx emissions is typically due to elevated flame temperatures associated with oxygen use leading to added thermal NOx formation. Innovative low flame temperature oxy-fuel burner designs have been developed and commercialized to minimize both thermal and fuel NOx formation for gas and oil fired industrial furnaces. To be effective these systems require close to 100% oxy-fuel combustion and the cost of oxygen is paid for by fuel savings and other benefits. For applications to coal-fired utility boilers at the current cost of oxygen, however, it is not economically feasible to use 100% oxygen for NOx control. In spite of this conventional wisdom, Praxair and its team members, in partnership with the US Department of Energy National Energy Technology Laboratory, have developed a novel way to use oxygen to reduce NOx emissions without resorting to complete oxy-fuel conversion. In this concept oxygen is added to the combustion process to enhance operation of a low NOx combustion system. Only a small fraction of combustion air is replaced with oxygen in the process. By selectively adding oxygen to a low NOx combustion system it is possible to reduce NOx emissions from nitrogen-containing fuels, including pulverized coal, while improving combustion characteristics such as unburned carbon. A combination of experimental work and modeling was used to define how well oxygen enhanced combustion could reduce NOx emissions. The results of this work suggest that small amounts of oxygen replacement can reduce the NOx emissions as compared to the air-alone system. NOx emissions significantly below 0.15 lbs/MMBtu were measured. Oxygen addition was also shown to reduce carbon in ash. Comparison of the costs of using oxygen for NOx control against competing technologies, such as SCR, show that this

  14. The influence of snow grain size and impurities on the vertical profiles of actinic flux and associated NOx emissions on the Antarctic and Greenland ice sheets

    Directory of Open Access Journals (Sweden)

    M. C. Zatko

    2013-04-01

    Full Text Available We use observations of the absorption properties of black carbon and non-black carbon impurities in near-surface snow collected near the research stations at South Pole and Dome C, Antarctica, and Summit, Greenland, combined with a snowpack actinic flux parameterization to estimate the vertical profile and e-folding depth of ultraviolet/near-visible (UV/near-vis actinic flux in the snowpack at each location. We have developed a simple and broadly applicable parameterization to calculate depth and wavelength dependent snowpack actinic flux that can be easily integrated into large-scale (e.g., 3-D models of the atmosphere. The calculated e-folding depths of actinic flux at 305 nm, the peak wavelength of nitrate photolysis in the snowpack, are 8–12 cm near the stations and 15–31 cm away (>11 km from the stations. We find that the e-folding depth is strongly dependent on impurity content and wavelength in the UV/near-vis region, which explains the relatively shallow e-folding depths near stations where local activities lead to higher snow impurity levels. We calculate the lifetime of NOx in the snowpack interstitial air produced by photolysis of snowpack nitrate against wind pumping (τwind pumping from the snowpack, and compare this to the calculated lifetime of NOx against chemical conversion to HNO3 (τchemical to determine whether the NOx produced at a given depth can escape from the snowpack to the overlying atmosphere. Comparison of τwind pumping and τchemical suggests efficient escape of photoproduced NOx in the snowpack to the overlying atmosphere throughout most of the photochemically active zone. Calculated vertical actinic flux profiles and observed snowpack nitrate concentrations are used to estimate the potential flux of NOx from the snowpack. Calculated NOx fluxes of 4.4 × 108–3.8 × 109 molecules cm−2 s−1 in remote polar locations and 3.2–8.2 × 108 molecules cm−2 s−1 near polar stations for January at Dome C and

  15. Decadal-scale joint inversion of NOx and SO2 using a hybrid 4D-Var / mass balance approach

    Science.gov (United States)

    Qu, Z.; Henze, D. K.; Capps, S.; Wang, Y.; Xu, X.; Wang, J.; Keller, M.

    2016-12-01

    Quantifying the emissions of nitrogen oxides (NOx) and sulfur dioxide (SO2) is important for improving our understanding of acid rain, formation of aerosols, and human health problems. Traditional top-down estimates have provided valuable constraints for NOx and SO2 emission inventories in China, but are either time-consuming (e.g., 4D-Var) or only crudely represent the influence of atmospheric transport and chemistry (e.g., mass balance). We develop an approach combining mass balance and an adjoint-based four-dimensional variational (4D-Var) methods that facilitates decadal-scale emission inversions. This hybrid inversion is first evaluated with a single species inversion using NO2 pseudo observations. In a set of seven-year pseudo observation test, hybrid posterior NOx emissions have smaller normalized mean square error (by 54% to 94%) than that of mass balance when compared to true emissions in most cases, and have slightly better performance in detecting emissions magnitudes and trends. Using this hybrid method, NO2 observations from the Ozone Monitoring Instrument (OMI), and the GEOS-Chem chemical transport model, we have derived monthly top-down NOx emissions for China from 2005 to 2012. Our posterior emissions have the same seasonality as recent bottom-up inventories, and smaller emissions (by 13.4% to 23.5%) as well as emission growth rate (by 0.6% to 4.1%). The hybrid method is further implemented for long-term joint inversion of NOx and SO2 emissions in China using combined observations of OMI NO2 and SO2 column densities. A 4D-Var inversion is first performed to optimize NOx and SO2 emissions in the base year using GEOS-Chem adjoint. Mass balance scaling factor is then applied to these posterior to improve their inter-annual variation. Overall, these studies augment the utility of remote sensing data for evaluating emission control strategies and mitigating the impact of NOx and SO2 on human health and the environment.

  16. Nox and renal disease.

    Science.gov (United States)

    Holterman, Chet E; Read, Naomi C; Kennedy, Chris R J

    2015-04-01

    Since the first demonstration of Nox enzyme expression in the kidney in the early 1990s and the subsequent identification of Nox4, or RENOX, a decade later, it has become apparent that the Nox family of reactive oxygen species (ROS) generating enzymes plays an integral role in the normal physiological function of the kidney. As our knowledge of Nox expression patterns and functions in various structures and specialized cell types within the kidney grows, so does the realization that Nox-derived oxidative stress contributes significantly to a wide variety of renal pathologies through their ability to modify lipids and proteins, damage DNA and activate transcriptional programmes. Diverse studies demonstrate key roles for Nox-derived ROS in kidney fibrosis, particularly in settings of chronic renal disease such as diabetic nephropathy. As the most abundant Nox family member in the kidney, much emphasis has been placed on the role of Nox4 in this setting. However, an ever growing body of work continues to uncover key roles for other Nox family members, not only in diabetic kidney disease, but in a diverse array of renal pathological conditions. The objective of the present review is to highlight the latest novel developments in renal Nox biology with an emphasis not only on diabetic nephropathy but many of the other renal disease contexts where oxidative stress is implicated.

  17. The Effect of Air Preheat at Atmospheric Pressure on the Formation of NO(x) in the Quick-Mix Sections of an Axially Staged Combustor

    Science.gov (United States)

    Vardakas, M. A.; Leong, M. Y.; Brouwer, J.; Samuelsen, G. S.; Holdeman, J. D.

    1999-01-01

    The Rich-burn/Quick-mix/Lean-burn (RQL) combustor concept has been proposed to minimize the formation of nitrogen oxides (NO(x)) in gas turbine systems. The success of this combustor strategy is dependent upon the efficiency of the mixing section bridging the fuel-rich and fuel-lean stages. Note that although these results were obtained from an experiment designed to study an RQL mixer, the link between mixing and NOx signatures is considerably broader than this application, in that the need to understand this link exists in most advanced combustors. The experiment reported herein was designed to study the effects of inlet air temperature on NO(x) formation in a mixing section. The results indicate that NO(x) emission is increased for all preheated cases compared to non-preheated cases. When comparing the various mixing modules, the affect of jet penetration is important, as this determines where NO(x) concentrations peak, and affects overall NO(x) production. Although jet air comprises 70 percent of the total airflow, the impact that jet air preheat has on overall NO(x) emissions is small compared to preheating both main and jet air flow.

  18. Ammonia-Free NOx Control System

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-09-30

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

  19. Ammonia-Free NOx Control System

    Energy Technology Data Exchange (ETDEWEB)

    Song Wu; Zhen Fan; Andrew H. Seltzer

    2005-09-30

    Research is being conducted under United States Department of Energy (DOE) Contract DEFC26-03NT41865 to develop a new technology to achieve very low levels of NOx emissions from pulverized coal fired boiler systems by employing a novel system level integration between the PC combustion process and the catalytic NOx reduction with CO present in the combustion flue gas. The combustor design and operating conditions will be optimized to achieve atypical flue gas conditions. This approach will not only suppress NOx generation during combustion but also further reduce NOx over a downstream catalytic reactor that does not require addition of an external reductant, such as ammonia. This report describes the work performed during the July 1 to September 30, 2005 time period.

  20. Ammonia-Free NOx Control System

    Energy Technology Data Exchange (ETDEWEB)

    Song Wu; Zhen Fan; Richard G. Herman

    2004-12-31

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

  1. NOx processing on Solar gas turbines; Turbines, traitement des nox sur les turbines a gaz solar

    Energy Technology Data Exchange (ETDEWEB)

    Chausse, X. [Spie Trindel, 95 - Cergy (France). Service TAG

    1997-12-31

    The Solar Company, in cooperation with Tuma Turbomach, has developed the SoLoNOx combustion system with a dry, lean, premixed compound, allowing for reduced NOx and CO emission levels (respectively 42 ppmv and 50 ppmv at 15 pc O{sub 2}). The combustor size is larger than a conventional combustor in order to maintain combustion efficiency and reduce carbon monoxide levels. Leaner combustion occurs at lower temperatures which produce less nitrogen oxides but require more volume to complete the combustion process. New developments should allow for a further reduction of NOx level at 25 ppmv

  2. DESIGN REPORT: LOW-NOX BURNERS FOR PACKAGE BOILERS

    Science.gov (United States)

    The report describes a low-NOx burner design, presented for residual-oil-fired industrial boilers and boilers cofiring conventional fuels and nitrated hazardous wastes. The burner offers lower NOx emission levels for these applications than conventional commercial burners. The bu...

  3. Understanding the origin of Paris Agreement emission uncertainties

    Science.gov (United States)

    Rogelj, Joeri; Fricko, Oliver; Meinshausen, Malte; Krey, Volker; Zilliacus, Johanna J. J.; Riahi, Keywan

    2017-06-01

    The UN Paris Agreement puts in place a legally binding mechanism to increase mitigation action over time. Countries put forward pledges called nationally determined contributions (NDC) whose impact is assessed in global stocktaking exercises. Subsequently, actions can then be strengthened in light of the Paris climate objective: limiting global mean temperature increase to well below 2 °C and pursuing efforts to limit it further to 1.5 °C. However, pledged actions are currently described ambiguously and this complicates the global stocktaking exercise. Here, we systematically explore possible interpretations of NDC assumptions, and show that this results in estimated emissions for 2030 ranging from 47 to 63 GtCO2e yr-1. We show that this uncertainty has critical implications for the feasibility and cost to limit warming well below 2 °C and further to 1.5 °C. Countries are currently working towards clarifying the modalities of future NDCs. We identify salient avenues to reduce the overall uncertainty by about 10 percentage points through simple, technical clarifications regarding energy accounting rules. Remaining uncertainties depend to a large extent on politically valid choices about how NDCs are expressed, and therefore raise the importance of a thorough and robust process that keeps track of where emissions are heading over time.

  4. Nitrogen stable isotope composition (δ15N) of vehicle-emitted NOx.

    Science.gov (United States)

    Walters, Wendell W; Goodwin, Stanford R; Michalski, Greg

    2015-02-17

    The nitrogen stable isotope ratio of NOx (δ(15)N-NOx) has been proposed as a regional indicator for NOx source partitioning; however, knowledge of δ(15)N values from various NOx emission sources is limited. This study presents a detailed analysis of δ(15)N-NOx emitted from vehicle exhaust, the largest source of anthropogenic NOx. To accomplish this, NOx was collected from 26 different vehicles, including gasoline and diesel-powered engines, using a modification of a NOx collection method used by the United States Environmental Protection Agency, and δ(15)N-NOx was analyzed. The vehicles sampled in this study emitted δ(15)N-NOx values ranging from -19.1 to 9.8‰ that negatively correlated with the emitted NOx concentrations (8.5 to 286 ppm) and vehicle run time because of kinetic isotope fractionation effects associated with the catalytic reduction of NOx. A model for determining the mass-weighted δ(15)N-NOx from vehicle exhaust was constructed on the basis of average commute times, and the model estimates an average value of -2.5 ± 1.5‰, with slight regional variations. As technology improvements in catalytic converters reduce cold-start emissions in the future, it is likely to increase current δ(15)N-NOx values emitted from vehicles.

  5. 40 CFR 1043.50 - Approval of methods to meet Tier 1 retrofit NOX standards.

    Science.gov (United States)

    2010-07-01

    ... retrofit NOX standards. 1043.50 Section 1043.50 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF NOX, SOX, AND PM EMISSIONS FROM MARINE ENGINES AND VESSELS SUBJECT TO THE MARPOL PROTOCOL § 1043.50 Approval of methods to meet Tier 1 retrofit NOX standards...

  6. Enhanced Combustion Low NOx Pulverized Coal Burner

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-06-30

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

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

    OpenAIRE

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

    2011-01-01

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

  8. Measurement of NOx fluxes from a tall tower in Beijing

    Science.gov (United States)

    Squires, Freya; Dunmore, Rachel; Lewis, Alastair; Vaughan, Adam; Mullinger, Neil; Nemitz, Eiko; Wild, Oliver; Zhang, Qiang; Hamilton, Jacqueline; Lee, James; Fu, Pingqing

    2017-04-01

    Nitrogen Oxides (NOx, the sum of nitrogen monoxide (NO) and nitrogen dioxide (NO2)) are significant anthropogenic pollutants emitted from most combustion processes. NOx is a precursor species to the formation of O3 and secondary aerosols and, in high concentrations, NO2 can have adverse effects on human health through action as a respiratory irritant. For these reasons, there has been increased focus on improving NOx emissions inventories, typically developed using 'bottom-up' estimates of emissions from their sources, which are used to predict current and future air quality and to guide abatement strategy. Recent studies have shown a discrepancy between NOx inventories and measured NOx emissions for UK cities, highlighting the limitations of bottom-up emissions inventories and the importance of accurate measurement data to improve the estimates. Similarly, inventories in China are associated with large uncertainties and are rapidly changing with time in response to economic development and new environmental regulation. Here, we present data collected as part of the Air Pollutants in Beijing (AIRPOLL-Beijing) campaign from an urban site located at the Institute of Atmospheric Physics, Chinese Academy of Sciences (IAP, CAS) (39˚ 58'28"N, 116˚ 22'16"E) in central Beijing. NOx concentrations were measured using a state-of-the-art chemiluminescence instrument, sampling from an inlet at 100 metres on a meteorological tower. Measurements at 5 Hz coupled with wind vector data measured by a sonic anemometer located at the same height as the inlet allowed NOx emission fluxes to be calculated using the eddy covariance method. Measurements were made during the period 11/11/2016 - 10/12/2016 and compared to existing emission estimates from The Multi-resolution Emission Inventory for China (MEIC) inventory. It is anticipated that this work will be used to evaluate the accuracy of emissions inventories for Beijing, to develop improved emissions estimates and thus provide

  9. Federal NOx Budget Trading Program and CAIR NOx and SO2 Trading Programs (40 CFR Part 97)

    Science.gov (United States)

    This part establishes general provisions and the applicability, permitting, allowance, excess emissions, monitoring, and opt-in provisions for the federal NOx Budget Trading Program as a means of mitigating interstate transport of ozone and nitrogen oxides

  10. Advanced combustor design concept to control NOx and air toxics

    Energy Technology Data Exchange (ETDEWEB)

    Eddings, E.G.; Pershing, D.W.; Molina, A.; Sarofim, A.F.; Spinti, J.P.; Veranth, J.

    1999-03-29

    Direct coal combustion needs to be a primary energy source for the electric utility industry and for heavy manufacturing during the next several decades because of the availability and economic advantage of coal relative to other fuels and because of the time required to produce major market penetration in the energy field. However, the major obstacle to coal utilization is a set of ever-tightening environmental regulations at both the federal and local level. It is, therefore, critical that fundamental research be conducted to support the development of low-emission, high-efficiency pulverized coal power systems. The objective of this program was to develop fundamental understanding regarding the impact of fuel and combustion changes on NOx formation, carbon burnout and air toxic emissions from pulverized coal (pc) combustion. During pc combustion, nitrogen in the coal can be oxidized to form nitrogen oxides (NO{sub x}). The 1990 Clean Air Act Amendments established much stricter NO{sub x} emissions limits for new and existing coal-fired plants, so there has been renewed interest in the processes by which NO{sub x} forms in pc flames. One of the least understood aspects of NO{sub x} formation from pc combustion is the process by which char-N (nitrogen remaining in the char after devolatilization) forms either NO{sub x} or N{sub 2}, and the development of a fundamental understanding of this process was a major focus of this research. The overall objective of this program was to improve the ability of combustion system designers and boiler manufacturers to build high efficiency, low emission pulverized coal systems by improving the design tools available to the industry. The specific program goals were to: Use laboratory experiments and modeling to develop fundamental understanding for a new submodel for char nitrogen oxidation (a critical piece usually neglected in most NOx models.); Use existing bench scale facilities to investigate alternative schemes to

  11. Low NOx combustion technologies for high-temperature natural gas combustion

    International Nuclear Information System (INIS)

    Flamme, Michael

    1999-01-01

    Because of the high process temperature which is required for some processes like glass melting and the high temperature to which the combustion air is preheated, NOx emission are extremely high. Even at these high temperatures, NOx emissions could be reduced drastically by using advanced combustion techniques such as staged combustion or flame-less oxidation, as experimental work has shown. In the case of oxy-fuel combustion, the NOx emission are also very high if conventional burners are used. The new combustion techniques achieve similar NOx reductions. (author)

  12. Analysis of NOx Budget Trading Program Units Brought into the CAIR NOx Ozone Season Trading Program

    Science.gov (United States)

    EPA analyzed the effect of having the large non-EGU units in the NBP and the CAIR NOX ozone season trading program and evaluated whether or not emissions from this group of units were reduced as a result of their inclusion in those trading programs.

  13. NOX Activation by Subunit Interaction and Underlying Mechanisms in Disease.

    Science.gov (United States)

    Rastogi, Radhika; Geng, Xiaokun; Li, Fengwu; Ding, Yuchuan

    2016-01-01

    Nicotinamide adenine dinucleotide phosphate (NAPDH) oxidase (NOX) is an enzyme complex with the sole function of producing superoxide anion and reactive oxygen species (ROS) at the expense of NADPH. Vital to the immune system as well as cellular signaling, NOX is also involved in the pathologies of a wide variety of disease states. Particularly, it is an integral player in many neurological diseases, including stroke, TBI, and neurodegenerative diseases. Pathologically, NOX produces an excessive amount of ROS that exceed the body's antioxidant ability to neutralize them, leading to oxidative stress and aberrant signaling. This prevalence makes it an attractive therapeutic target and as such, NOX inhibitors have been studied and developed to counter NOX's deleterious effects. However, recent studies of NOX have created a better understanding of the NOX complex. Comprised of independent cytosolic subunits, p47- phox , p67- phox , p40- phox and Rac , and membrane subunits, gp91- phox and p22- phox , the NOX complex requires a unique activation process through subunit interaction. Of these subunits, p47- phox plays the most important role in activation, binding and translocating the cytosolic subunits to the membrane and anchoring to p22- phox to organize the complex for NOX activation and function. Moreover, these interactions, particularly that between p47- phox and p22- phox , are dependent on phosphorylation initiated by upstream processes involving protein kinase C (PKC). This review will look at these interactions between subunits and with PKC. It will focus on the interaction involving p47- phox with p22- phox , key in bringing the cytosolic subunits to the membrane. Furthermore, the implication of these interactions as a target for NOX inhibitors such as apocynin will be discussed as a potential avenue for further investigation, in order to develop more specific NOX inhibitors based on the inhibition of NOX assembly and activation.

  14. Avaliação da emissão de co, no e nox na exaustão de motor diesel abastecido com combustível aditivado

    Directory of Open Access Journals (Sweden)

    Gilson Rodrigo de Miranda

    2011-01-01

    Full Text Available A poluição atmosférica tem emergido como um dos maiores problemas globais. Na última década, o desenvolvimento de novos motores, o uso de diferentes formas de tratamento dos gases na exaustão e o aumento na qualidade dos combustíveis foram medidas utilizadas na redução de poluentes (regulamentados ou não. Entre os vários desenvolvimentos para reduzir as emissões, a aplicação de aditivos oxigenados e parafínicos ao óleo diesel é uma medida que vem se mostrando efetiva e rápida para a redução dos poluentes emitidos. Neste trabalho estudou-se a influência de compostos oxigenados (Dietil Eter (DEE, 1-Dodecanol (DOD, Acetato de 2-Metoxietila (MEA e Terc-butanol (TERC e parafínicos (Heptano (HEPT e n-Hexadecano (CET adicionados ao óleo diesel com o intuito de melhorar a qualidade das emissões de CO, NO e NOx na exaustão de motor diesel, monocilíndrico. Os combustíveis utilizados nos estudos são formulações do óleo diesel de referência, nomeado aqui S10, que contém baixo teor de enxofre (Abstract Air pollution has emerged as major global problems. In the last decade, the development of new engines, the use of different forms of treatment of exhaust gases and the increase in fuel quality were used to reduce pollutants (regulated or not. Among the various developments to reduce emissions, the use of oxygenated additives to diesel and paraffin is a quick and effective measure to reduce pollutants. In this work we studied the influence of oxygenated compounds (diethyl ether (DEE, 1-dodecanol (DOD, 2-methoxy-acetate (MEA and terc-butanol (TERC and paraffin (heptane (HEPT and n- hexadecane (CET added to diesel in order to improve the quality of CO, NO and NOx in the exhaust of diesel engine, single cylinder. The fuels used in the studies are formulations of diesel reference, here named S10, which contains low sulfur (

  15. State of the art of NOx mitigation technologies and their effect on the performance and emission characteristics of biodiesel-fueled Compression Ignition engines

    International Nuclear Information System (INIS)

    Palash, S.M.; Masjuki, H.H.; Kalam, M.A.; Masum, B.M.; Sanjid, A.; Abedin, M.J.

    2013-01-01

    Highlights: • Different NO x reduction technologies are discussed along with their implementation. • EGR rate up to 25% is feasible considering engine performance and other emissions. • ITR technology reduces NO x fairly but increases other emissions, it also reduces performance. • LTC reduces NO x and PM emissions simultaneously but increases HC and CO emissions. • Water injection and emulsion reduce NO x (up to 38%) and PM but increases HC and CO emissions. - Abstract: Biodiesel fuels have the potential to become a reliable substitute for diesel which is used moderately to meet the current energy demands. This fuel can be produced from new or used vegetable oils, non-edible sources and animal fats, which are non-toxic, biodegradable and renewable. In spite of the many advantages of using biodiesel, most of the researchers have reported that they produce higher NO x emissions compared to diesel, which is a deterrent to the market expansion of these fuels. In this study, the different paths to reduce NO x emissions from diesel engines by applying several technologies, such as using additives into fuel, exhaust gas recirculation (EGR), water injection (WI), emulsion technology (ET), injection timing retardation (ITR), simultaneous technology (ST) and low temperature combustion (LTC) mode are reviewed briefly. The impacts of different NO x mitigation technologies on biodiesel-fueled diesel engine performance and emissions are also analyzed critically and different methods of their implementation are shown. This paper also provides a comparison of different NO x mitigation technologies based on previous articles related to this topic. From this comparative study, it was found that the average reduction of NO x emissions by using additives, EGR, WI and ET, ITR, ST and LTC are in the ranges 4–45%, 26–84%, 10–38%, 9.77–37%, 22–95% and 66–93% respectively, compared to biodiesel combustion without applying technologies. However, the average reduction

  16. THE DETERMINATION THE POLLUTION EMISSIONS OF SO2, NOX, CO, CO2 AND O2 FROM THE CHANNELS OF BURNT GAS ON BOILER OF 420 T/H - STEAM, IN THE SIGHT APPLICATION PROCEEDING TO REDUCE OF THESE

    Directory of Open Access Journals (Sweden)

    Valentin Nedeff

    2007-03-01

    Full Text Available The work present the results obtained after dynamic analyze the pollution emissions of SO2, NOx, CO, CO2 and O2 on evacuation channels of burnt gas on boiler of 420 t/h steam, having right the basic combustible the lignite, and auxiliary combustible the fuel oil and the natural gas. The values of pollution emission was analyze beside the admissible maxims values required by European legislation for Romania in the year 2005. The conclusion elaborated it adverted to: the values of oxides azoth, carry they frame in the limits provide in Environmental Authorization, under 60 mg/Nmc on 6% oxygen, the concentration values of SO2 which was bigger in report with one authorized comprised between 3500-3900 mg/Nmc confronted by 3400 mg/Nm. For integration in the foresee Government Decision 541/2003 aren't sufficient just proceeding of below reduce SO2, must take and another measures such as: get the fuel with quantity of sulphur 0.5% and with a content of ash below 35%.

  17. 77 FR 28375 - Adequacy Status of the Submitted 2008 and 2022 VOC and NOX

    Science.gov (United States)

    2012-05-14

    ... ENVIRONMENTAL PROTECTION AGENCY [EPA-R01-OAR-2012-0290; A-1-FRL-9672-6] Adequacy Status of the Submitted 2008 and 2022 VOC and NOX Motor Vehicle Emissions Budgets for Transportation Conformity Purposes... following table: Adequate Motor Vehicle Emissions Budgets VOC (tons per NOX (tons per summer day) summer day...

  18. Developing a Method for Resolving NOx Emission Inventory Biases Using Discrete Kalman Filter Inversion, Direct Sensitivities, and Satellite-Based Columns

    Science.gov (United States)

    An inverse method was developed to integrate satellite observations of atmospheric pollutant column concentrations and direct sensitivities predicted by a regional air quality model in order to discern biases in the emissions of the pollutant precursors.

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

    Science.gov (United States)

    Kundu, Krishna P.; Nguyen, H. 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.

  20. Evaluation of reported NOx emission trends between 2005 and 2013 by assimilation of OMI-NO2 data into LOTOS-EUROS

    Science.gov (United States)

    Schaap, Martijn; Segers, Arjo; Curier, Lyana; Timmermans, Renske

    2016-04-01

    Consistent and long time series of remotely sensed trace gas levels may provide a useful tool to estimate surface emissions and emission trends. We use the OMI-NO2 product in conjunction with the LOTOS-EUROS CTM to estimate European emission trends through correction of the OMI-time series for meteorological variability as well as through assimilation using an ensemble kalman filter system (EnKF). The chemistry transport model captures a large fraction of the variability in NO2 columns at a synoptic timescale, although a seasonal signal in the bias between the modeled and retrieved column data remains. Prior to the assimilation, the OMI-NO2 data have been analyzed to establish the spatially variable temporal and spatial correlation lengths, required for the settings in the EnKF system. The assimilation run for 2005-2013 was performed using constant 2005 emissions to be able to quantify the emission change. The assimilation reduces the model-observation differences considerably. Significant negative trends of 2-3 % per year (as compared to 2005) were found in highly industrialized areas across Western Europe. The assimilation system also identifies the areas with major emission reductions in e.g. northern Spain as identified in earlier studies. Comparison of the trends derived from the assimilation and the data itself shows a high level of agreement, both the trends found in this way are smaller than those reported.

  1. Dynamic Management of NOx and SO2 Emissions in the Texas and Mid-Atlantic Electric Power Systems and Implications for Air Quality.

    Science.gov (United States)

    McDonald-Buller, Elena; Kimura, Yosuke; Craig, Michael; McGaughey, Gary; Allen, David; Webster, Mort

    2016-02-02

    Cap and trade programs have historically been designed to achieve annual or seasonal reductions in emissions of nitrogen oxides and sulfur dioxide from power plants. Emissions reductions may not be temporally coincident with meteorological conditions conducive to the formation of peak ozone and fine particulate matter concentrations. Integrated power system and air quality modeling methods were developed to evaluate time-differentiated emissions price signals on high ozone days in the Mid-Atlantic portion of the Pennsylvania-New Jersey-Maryland (PJM) Interconnection and Electric Reliability Council of Texas (ERCOT) grids. Sufficient flexibility exists in the two grids with marked differences in demand and fuel generation mix to accommodate time-differentiated emissions pricing alone or in combination with a season-wide program. System-wide emissions reductions and production costs from time-differentiated pricing are shown to be competitive with those of a season-wide program on high ozone days and would be more cost-effective if the primary policy goal was to target emissions reductions on these days. Time-differentiated pricing layered as a complement to the Cross-State Air Pollution Rule had particularly pronounced benefits for the Mid-Atlantic PJM system that relies heavily on coal-fired generation. Time-differentiated pricing aimed at reducing ozone concentrations had particulate matter reduction co-benefits, but if particulate matter reductions are the primary objective, other approaches to time-differentiated pricing may lead to greater benefits.

  2. GHG Emissions, Economic Growth and Urbanization: A Spatial Approach

    Directory of Open Access Journals (Sweden)

    Li Li

    2016-05-01

    Full Text Available To gain a greater understanding of the spatial spillover effect of greenhouse gas emissions and their influencing factors, this paper provides a spatial analysis of four gas pollutants (CO2 emissions, SO2 emissions, NOx emissions, and dust emissions. Focusing on China, the paper also explores whether the four gas pollutants are influenced by the emissions of neighboring regions and other possible sources. The paper uses a global spatial autocorrelation analysis, local spatial association analysis and spatial lag model for empirical work. The results suggest that CO2, SO2, and NOx emissions show significant positive results for both the spatial correlation and space cluster effect in provincial space distribution.CO2 and NOx emissions have a significant positive spillover effect, while the SO2 emissions’ spatial spillover effect is positive but not significant. Economic growth and urbanization are the key determinants of CO2, dust, and NOx emissions, while energy efficiency and industrialization do not appear to play a role. This raises questions about the method of examining the spatial relationship between gas pollution, economic growth and urbanization in the future.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-06-30

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

  4. Ozone production and its sensitivity to NOx and VOCs: results from the DISCOVER-AQ field experiment, Houston 2013

    Directory of Open Access Journals (Sweden)

    G. M. Mazzuca

    2016-11-01

    Full Text Available An observation-constrained box model based on the Carbon Bond mechanism, version 5 (CB05, was used to study photochemical processes along the NASA P-3B flight track and spirals over eight surface sites during the September 2013 Houston, Texas deployment of the NASA Deriving Information on Surface Conditions from COlumn and VERtically Resolved Observations Relevant to Air Quality (DISCOVER-AQ campaign. Data from this campaign provided an opportunity to examine and improve our understanding of atmospheric photochemical oxidation processes related to the formation of secondary air pollutants such as ozone (O3. O3 production and its sensitivity to NOx and volatile organic compounds (VOCs were calculated at different locations and times of day. Ozone production efficiency (OPE, defined as the ratio of the ozone production rate to the NOx oxidation rate, was calculated using the observations and the simulation results of the box and Community Multiscale Air Quality (CMAQ models. Correlations of these results with other parameters, such as radical sources and NOx mixing ratio, were also evaluated. It was generally found that O3 production tends to be more VOC-sensitive in the morning along with high ozone production rates, suggesting that control of VOCs may be an effective way to control O3 in Houston. In the afternoon, O3 production was found to be mainly NOx-sensitive with some exceptions. O3 production near major emissions sources such as Deer Park was mostly VOC-sensitive for the entire day, other urban areas near Moody Tower and Channelview were VOC-sensitive or in the transition regime, and areas farther from downtown Houston such as Smith Point and Conroe were mostly NOx-sensitive for the entire day. It was also found that the control of NOx emissions has reduced O3 concentrations over Houston but has led to larger OPE values. The results from this work strengthen our understanding of O3 production; they indicate that controlling NOx

  5. Impacts of NOx reducing antioxidant additive on performance and emissions of a multi-cylinder diesel engine fueled with Jatropha biodiesel blends

    International Nuclear Information System (INIS)

    Palash, S.M.; Kalam, M.A.; Masjuki, H.H.; Arbab, M.I.; Masum, B.M.; Sanjid, A.

    2014-01-01

    Highlights: • Environmental benefits of JB blends were found but adverse impact on NO x . • Addition of 0.15% (m) DPPD in JB20, average reduction in NO up to 16.54%. • In some cases, engine power is reduced with DPPD additive. • Emissions of HC and CO for JB blends with DPPD were lower compared to diesel. • Addition of DPPD in JB blends reduction of EGT was found. - Abstract: Energy requirements are increasing rapidly due to fast industrialization and the increased number of vehicles on the road. The use of biodiesel in diesel engines instead of diesel results in the proven reduction of harmful exhaust emissions. However, most researchers have reported that they produce higher NO x emissions compared to diesel, which is a deterrent to the expansion of the market for these fuels. Several proposed pathways try to account for NO x formation during the combustion process. Among them, the Fenimore mechanism explains that fuel radicals formed during the combustion process react with nitrogen from the air to form NO x . It could be proposed that if these radical reactions could be terminated, the NO x formation rate for biodiesel combustion would decrease. An experimental study was conducted on a four-cylinder diesel engine to evaluate the performance and emission characteristics of Jatropha biodiesel blends (JB5, JB10, JB15 and JB20) with and without the addition of N,N′-diphenyl-1,4-phenylenediamine (DPPD) antioxidant. For each tested fuel, the engine performance and emissions were measured at engine speeds 1000–4000 rpm at an interval of 500 rpm under the full throttle condition. The results showed that this antioxidant additive could reduce NO x emissions significantly with a slight penalty in terms of engine power and Brake Specific Fuel Consumption (BSFC) as well as CO and HC emissions. However, when compared to diesel combustion, the emissions of HC and CO with the addition of the DPPD additive were found to be nearly the same or lower. By the

  6. Fleet average NOx emission performance of 2007 model year light-duty vehicles, light-duty trucks and medium-duty passenger vehicles

    International Nuclear Information System (INIS)

    2009-09-01

    This report summarized the regulatory requirements related to nitrous oxide (NO x ) fleet averaging for light-duty vehicles, light-duty trucks, and medium-duty passenger vehicles under the On-Road Vehicle and Engine Emission Regulations. The regulations introduced more stringent national emission standards for on-road vehicles and engines and include technical standards that establish maximum limits on vehicle exhaust emissions. The fleet average NO x emission performance of individual companies and the overall Canadian fleet for 2007 was summarized, and the effectiveness of the Canadian fleet average NO x emission program was evaluated in relation to its environmental performance objectives. A total of 22 companies submitted reports for 294 test groups comprising 1,599,051 vehicles of the 2007 model year. The average NO x value for the entire LDV/LLDT fleet was 0.06897630 grams per mile. The average value for the HLDT/MDPV fleet was 0.160668 grams per mile. NO x values for both overall fleets remained better than the corresponding fleet average NO x standards, and were consistent with the environmental performance objectives of the regulations. 9 tabs., 3 figs.

  7. Fleet average NOx emission performance of 2004 model year light-duty vehicles, light-duty trucks and medium-duty passenger vehicles

    International Nuclear Information System (INIS)

    2006-05-01

    The On-Road Vehicle and Engine Emission Regulations came into effect on January 1, 2004. The regulations introduced more stringent national emission standards for on-road vehicles and engines, and also required that companies submit reports containing information concerning the company's fleets. This report presented a summary of the regulatory requirements relating to nitric oxide (NO x ) fleet average emissions for light-duty vehicles, light-duty trucks, and medium-duty passenger vehicles under the new regulations. The effectiveness of the Canadian fleet average NO x emission program at achieving environmental performance objectives was also evaluated. A summary of the fleet average NO x emission performance of individual companies was presented, as well as the overall Canadian fleet average of the 2004 model year based on data submitted by companies in their end of model year reports. A total of 21 companies submitted reports covering 2004 model year vehicles in 10 test groups, comprising 1,350,719 vehicles of the 2004 model year manufactured or imported for the purpose of sale in Canada. The average NO x value for the entire Canadian LDV/LDT fleet was 0.2016463 grams per mile. The average NO x values for the entire Canadian HLDT/MDPV fleet was 0.321976 grams per mile. It was concluded that the NO x values for both fleets were consistent with the environmental performance objectives of the regulations for the 2004 model year. 9 tabs

  8. Method for reduction of the NOX emissions in marine auxiliary diesel engine using the fuel mixtures containing biodiesel using HCCI combustion.

    Science.gov (United States)

    Puškár, Michal; Kopas, Melichar; Puškár, Dušan; Lumnitzer, Ján; Faltinová, Eva

    2018-02-01

    The marine auxiliary diesel engines installed in the large transoceanic ships are used in order to generate the electricity but at the same time these engines are able to produce a significant amount of the harmful exhaust gas emissions. Therefore the International Maritime Organisation (IMO) concluded an agreement, which has to control generating of gaseous emissions in maritime transport. From this reason started to be used some of the alternative fuels in this branch. There was performed a study, which investigated emissions of the auxiliary marine diesel engine during application of the experimental fuels. The different testing fuels were created using the ratios 0%, 50%, 80% and 100% between the biodiesel and the ULSDF (Ultra Low Sulphur Diesel Fuel). The experimental measurements were performed at the different engine loading levels and various engine speeds in order to investigate an influence of the mixed fuels on the engine operational characteristics. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Achieving New Source Performance Standards (NSPS) Emission Standards Through Integration of Low-NOx Burners with an Optimization Plan for Boiler Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Wayne Penrod

    2006-12-31

    The objective of this project was to demonstrate the use of an Integrated Combustion Optimization System to achieve NO{sub X} emission levels in the range of 0.15 to 0.22 lb/MMBtu while simultaneously enabling increased power output. The project plan consisted of the integration of low-NO{sub X} burners and advanced overfire air technology with various process measurement and control devices on the Holcomb Station Unit 1 boiler. The plan included the use of sophisticated neural networks or other artificial intelligence technologies and complex software to optimize several operating parameters, including NO{sub X} emissions, boiler efficiency, and CO emissions. The program was set up in three phases. In Phase I, the boiler was equipped with sensors that can be used to monitor furnace conditions and coal flow to permit improvements in boiler operation. In Phase II, the boiler was equipped with burner modifications designed to reduce NO{sub X} emissions and automated coal flow dampers to permit on-line fuel balancing. In Phase III, the boiler was to be equipped with an overfire air system to permit deep reductions in NO{sub X} emissions. Integration of the overfire air system with the improvements made in Phases I and II would permit optimization of boiler performance, output, and emissions. This report summarizes the overall results from Phases I and II of the project. A significant amount of data was collected from the combustion sensors, coal flow monitoring equipment, and other existing boiler instrumentation to monitor performance of the burner modifications and the coal flow balancing equipment.

  10. Gaseous nitrous acid (HONO) and nitrogen oxides (NOx) emission from gasoline and diesel vehicles under real-world driving test cycles.

    Science.gov (United States)

    Trinh, Ha T; Imanishi, Katsuma; Morikawa, Tazuko; Hagino, Hiroyuki; Takenaka, Norimichi

    2017-04-01

    Reactive nitrogen species emission from the exhausts of gasoline and diesel vehicles, including nitrogen oxides (NO x ) and nitrous acid (HONO), contributes as a significant source of photochemical oxidant precursors in the ambient air. Multiple laboratory and on-road exhaust measurements have been performed to estimate the NO x emission factors from various vehicles and their contribution to atmospheric pollution. Meanwhile, HONO emission from vehicle exhaust has been under-measured despite the fact that HONO can contribute up to 60% of the total hydroxyl budget during daytime and its formation pathway is not fully understood. A profound traffic-induced HONO to NO x ratio of 0.8%, established by Kurtenbach et al. since 2001, has been widely applied in various simulation studies and possibly linked to under-estimation of HONO mixing ratios and OH radical budget in the morning. The HONO/NO x ratios from direct traffic emission have become debatable when it lacks measurements for direct HONO emission from vehicles upon the fast-changing emission reduction technology. Several recent studies have reported updated values for this ratio. This study has reported the measurement of HONO and NO x emission as well as the estimation of exhaust-induced HONO/NO x ratios from gasoline and diesel vehicles using different chassis dynamometer tests under various real-world driving cycles. For the tested gasoline vehicle, which was equipped with three-way catalyst after-treatment device, HONO/NO x ratios ranged from 0 to 0.95 % with very low average HONO concentrations. For the tested diesel vehicle equipped with diesel particulate active reduction device, HONO/NO x ratios varied from 0.16 to 1.00 %. The HONO/NO x ratios in diesel exhaust were inversely proportional to the average speeds of the tested vehicles. Photolysis of HONO is a dominant source of morning OH radicals. Conventional traffic-induced HONO/NO x ratio of 0.8% has possibly linked to underestimation of the total HONO

  11. Detecting and understanding extragalactic Lyman α emission using 3D spectroscopy

    OpenAIRE

    Herenz, Edmund Christian (Master of Science)

    2016-01-01

    In this thesis we use integral-field spectroscopy to detect and understand of Lyman α (Lyα) emission from high-redshift galaxies. Intrinsically the Lyα emission at λ = 1216 Å is the strongest recombination line from galaxies. It arises from the 2p → 1s transition in hydrogen. In star-forming galaxies the line is powered by ionisation of the interstellar gas by hot O- and B- stars. Galaxies with star-formation rates of 1 - 10 Msol/year are expected to have Lyα luminosities of 42 dex - 4...

  12. Integrated powertrain control to meet future CO2 and Euro-6 emissions targets for a diesel hybrid with SCR-deNOx system

    NARCIS (Netherlands)

    Willems, F.P.T.; Foster, D.L.

    2009-01-01

    A new concept is introduced to optimize the performance of the entire powertrain: Integrated Powertrain Control (IPC). In this concept, the synergy between engine, driveline and aftertreatment system is exploited by integrated energy and emission management. As a result, fuel efficiency and

  13. NOx emissions and thermal efficiencies of small scale biomass-fuelled combustion plant with reference to process industries in a developing country

    International Nuclear Information System (INIS)

    Tariq, A.S.; Purvis, M.R.I.

    1996-01-01

    Solid biomass materials are an important industrial fuel in many developing countries and also show good potential for usage in Europe within a future mix of renewable energy resources. The sustainable use of wood fuels for combustion relies on operation of plant with acceptable thermal efficiency. There is a clear link between plant efficiency and environmental impacts due to air pollution and deforestation. To supplement a somewhat sparse literature on thermal efficiencies and nitrogen oxide emissions from biomass-fuelled plants in developing countries, this paper presents results for tests carried out on 14 combustion units obtained during field trials in Sri Lanka. The plants tested comprised steam boilers and process air heaters. Biomass fuels included: rubber-wood, fuelwood from natural forests; coconut shells; rice husks; and sugar can bagasse. Average NO x (NO and NO 2 ) emissions for the plants were found to be 47 gNO 2 GJ -1 with 18% conversion of fuel nitrogen. The former value is the range of NO x emission values quoted for combustion of coal in grate-fired systems; some oil-fired systems and systems operating on natural gas, but is less than the emission levels for the combustion of pulverized fuel and heavy fuel oil. This value is significantly within current European standards for NO x emission from large combustion plants. Average thermal efficiency of the plants was found to be 50%. Observations made on operational practices demonstrated that there is considerable scope for the improvement of this thermal efficiency value by plant supervisor training, drying of fuelwood and the use of simple instruments for monitoring plant performance. (Author)

  14. Effects of NOX Storage Component on Ammonia Formation in TWC for Passive SCR NOX Control in Lean Gasoline Engines

    Energy Technology Data Exchange (ETDEWEB)

    Prikhodko, Vitaly Y. [ORNL; Pihl, Josh A. [ORNL; Toops, Todd J. [ORNL; Parks, II, James E. [ORNL

    2018-04-01

    A prototype three-way catalyst (TWC) with NOX storage component was evaluated for ammonia (NH3) generation on a 2.0-liter BMW lean burn gasoline direct injection engine as a component in a passive ammonia selective catalytic reduction (SCR) system. The passive NH3 SCR system is a potential approach for controlling nitrogen oxides (NOX) emissions from lean burn gasoline engines. In this system, NH3 is generated over a close-coupled TWC during periodic slightly-rich engine operation and subsequently stored on an underfloor SCR catalyst. Upon switching to lean, NOX passes through the TWC and is reduced by the stored NH3 on the SCR catalyst. Adding a NOX storage component to a TWC provides two benefits in the context of a passive SCR system: (1) enabling longer lean operation by storing NOX upstream and preserving NH3 inventory on the downstream SCR catalyst; and (2) increasing the quantity and rate of NH3 production during rich operation. Since the fuel penalty associated with passive SCR NOX control depends on the fraction of time that the engine is running rich rather than lean, both benefits (longer lean times and shorter rich times achieved via improved NH3 production) will decrease the passive SCR fuel penalty. However, these benefits are primarily realized at low to moderate temperatures (300-500 °C), where the NOX storage component is able to store NOX, with little to no benefit at higher temperatures (>500 °C), where NOX storage is no longer effective. This study discusses engine parameters and control strategies affecting the NH3 generation over a TWC with NOX storage component.

  15. Expected ozone benefits of reducing nitrogen oxide (NOx) emissions from coal-fired electricity generating units in the eastern United States.

    Science.gov (United States)

    Vinciguerra, Timothy; Bull, Emily; Canty, Timothy; He, Hao; Zalewsky, Eric; Woodman, Michael; Aburn, George; Ehrman, Sheryl; Dickerson, Russell R

    2017-03-01

    On hot summer days in the eastern United States, electricity demand rises, mainly because of increased use of air conditioning. Power plants must provide this additional energy, emitting additional pollutants when meteorological conditions are primed for poor air quality. To evaluate the impact of summertime NO x emissions from coal-fired electricity generating units (EGUs) on surface ozone formation, we performed a series of sensitivity modeling forecast scenarios utilizing EPA 2018 version 6.0 emissions (2011 base year) and CMAQ v5.0.2. Coal-fired EGU NO x emissions were adjusted to match the lowest NO x rates observed during the ozone seasons (April 1-October 31) of 2005-2012 (Scenario A), where ozone decreased by 3-4 ppb in affected areas. When compared to the highest emissions rates during the same time period (Scenario B), ozone increased ∼4-7 ppb. NO x emission rates adjusted to match the observed rates from 2011 (Scenario C) increased ozone by ∼4-5 ppb. Finally in Scenario D, the impact of additional NO x reductions was determined by assuming installation of selective catalytic reduction (SCR) controls on all units lacking postcombustion controls; this decreased ozone by an additional 2-4 ppb relative to Scenario A. Following the announcement of a stricter 8-hour ozone standard, this analysis outlines a strategy that would help bring coastal areas in the mid-Atlantic region closer to attainment, and would also provide profound benefits for upwind states where most of the regional EGU NO x originates, even if additional capital investments are not made (Scenario A). With the 8-hr maximum ozone National Ambient Air Quality Standard (NAAQS) decreasing from 75 to 70 ppb, modeling results indicate that use of postcombustion controls on coal-fired power plants in 2018 could help keep regions in attainment. By operating already existing nitrogen oxide (NO x ) removal devices to their full potential, ozone could be significantly curtailed, achieving ozone

  16. Influence of polymethyl acrylate additive on the formation of particulate matter and NOX emission of a biodiesel-diesel-fueled engine.

    Science.gov (United States)

    Monirul, Islam Mohammad; Masjuki, Haji Hassan; Kalam, Mohammad Abdul; Zulkifli, Nurin Wahidah Mohd; Shancita, Islam

    2017-08-01

    The aim of this study is to investigate the effect of the polymethyl acrylate (PMA) additive on the formation of particulate matter (PM) and nitrogen oxide (NO X ) emission from a diesel coconut and/or Calophyllum inophyllum biodiesel-fueled engine. The physicochemical properties of 20% of coconut and/or C. inophyllum biodiesel-diesel blend (B20), 0.03 wt% of PMA with B20 (B20P), and diesel fuel were measured and compared to ASTM D6751, D7467, and EN 14214 standard. The test results showed that the addition of PMA additive with B20 significantly improves the cold-flow properties such as pour point (PP), cloud point (CP), and cold filter plugging point (CFPP). The addition of PMA additives reduced the engine's brake-specific energy consumption of all tested fuels. Engine emission results showed that the additive-added fuel reduce PM concentration than B20 and diesel, whereas the PM size and NO X emission both increased than B20 fuel and baseline diesel fuel. Also, the effect of adding PMA into B20 reduced Carbon (C), Aluminum (Al), Potassium (K), and volatile materials in the soot, whereas it increased Oxygen (O), Fluorine (F), Zinc (Zn), Barium (Ba), Chlorine (Cl), Sodium (Na), and fixed carbon. The scanning electron microscope (SEM) results for B20P showed the lower agglomeration than B20 and diesel fuel. Therefore, B20P fuel can be used as an alternative to diesel fuel in diesel engines to lower the harmful emissions without compromising the fuel quality.

  17. Impacts of Combined Cooling, Heating and Power Systems, and Rainwater Harvesting on Water Demand, Carbon Dioxide, and NOx Emissions for Atlanta.

    Science.gov (United States)

    James, Jean-Ann; Sung, Sangwoo; Jeong, Hyunju; Broesicke, Osvaldo A; French, Steven P; Li, Duo; Crittenden, John C

    2018-01-02

    The purpose of this study is to explore the potential water, CO 2 and NO x emission, and cost savings that the deployment of decentralized water and energy technologies within two urban growth scenarios can achieve. We assess the effectiveness of urban growth, technological, and political strategies to reduce these burdens in the 13-county Atlanta metropolitan region. The urban growth between 2005 and 2030 was modeled for a business as usual (BAU) scenario and a more compact growth (MCG) scenario. We considered combined cooling, heating and power (CCHP) systems using microturbines for our decentralized energy technology and rooftop rainwater harvesting and low flow fixtures for the decentralized water technologies. Decentralized water and energy technologies had more of an impact in reducing the CO 2 and NO x emissions and water withdrawal and consumption than an MCG growth scenario (which does not consider energy for transit). Decentralized energy can reduce the CO 2 and NO x emissions by 8% and 63%, respectively. Decentralized energy and water technologies can reduce the water withdrawal and consumption in the MCG scenario by 49% and 50% respectively. Installing CCHP systems on both the existing and new building stocks with a net metering policy could reduce the CO 2 , NO x , and water consumption by 50%, 90%, and 75% respectively.

  18. Nitrous oxide emissions from soils: how well do we understand the processes and their controls?

    Science.gov (United States)

    Butterbach-Bahl, Klaus; Baggs, Elizabeth M.; Dannenmann, Michael; Kiese, Ralf; Zechmeister-Boltenstern, Sophie

    2013-01-01

    Although it is well established that soils are the dominating source for atmospheric nitrous oxide (N2O), we are still struggling to fully understand the complexity of the underlying microbial production and consumption processes and the links to biotic (e.g. inter- and intraspecies competition, food webs, plant–microbe interaction) and abiotic (e.g. soil climate, physics and chemistry) factors. Recent work shows that a better understanding of the composition and diversity of the microbial community across a variety of soils in different climates and under different land use, as well as plant–microbe interactions in the rhizosphere, may provide a key to better understand the variability of N2O fluxes at the soil–atmosphere interface. Moreover, recent insights into the regulation of the reduction of N2O to dinitrogen (N2) have increased our understanding of N2O exchange. This improved process understanding, building on the increased use of isotope tracing techniques and metagenomics, needs to go along with improvements in measurement techniques for N2O (and N2) emission in order to obtain robust field and laboratory datasets for different ecosystem types. Advances in both fields are currently used to improve process descriptions in biogeochemical models, which may eventually be used not only to test our current process understanding from the microsite to the field level, but also used as tools for up-scaling emissions to landscapes and regions and to explore feedbacks of soil N2O emissions to changes in environmental conditions, land management and land use. PMID:23713120

  19. Using Satellite Remote Sensing and Modelling for Insights into N02 Air Pollution and NO2 Emissions

    Science.gov (United States)

    Lamsal, L. N.; Martin, R. V.; Krotkov, N. A.; Bucsela, E. J.; Celarier, E. A.; vanDonkelaar, A.; Parrish, D.

    2012-01-01

    Nitrogen oxides (NO(x)) are key actors in air quality and climate change. Satellite remote sensing of tropospheric NO2 has developed rapidly with enhanced spatial and temporal resolution since initial observations in 1995. We have developed an improved algorithm and retrieved tropospheric NO2 columns from Ozone Monitoring Instrument. Column observations of tropospheric NO2 from the nadir-viewing satellite sensors contain large contributions from the boundary layer due to strong enhancement of NO2 in the boundary layer. We infer ground-level NO2 concentrations from the OMI satellite instrument which demonstrate significant agreement with in-situ surface measurements. We examine how NO2 columns measured by satellite, ground-level NO2 derived from satellite, and NO(x) emissions obtained from bottom-up inventories relate to world's urban population. We perform inverse modeling analysis of NO2 measurements from OMI to estimate "top-down" surface NO(x) emissions, which are used to evaluate and improve "bottom-up" emission inventories. We use NO2 column observations from OMI and the relationship between NO2 columns and NO(x) emissions from a GEOS-Chem model simulation to estimate the annual change in bottom-up NO(x) emissions. The emission updates offer an improved estimate of NO(x) that are critical to our understanding of air quality, acid deposition, and climate change.

  20. Effect of the air-fuel mixing on the NOx yield in a low-emission gas-turbine plant combustor

    Science.gov (United States)

    Vasil'ev, V. D.; Bulysova, L. A.; Berne, A. L.

    2016-04-01

    The article deals with construction of a simplified model of inhibition of nitric oxides formed in the combustors of the gas-turbine plants (GTPs) operating on natural gas. A combustor in which premixed, lean air-fuel mixtures are burnt is studied theoretically and experimentally. The research was carried out using a full-scale combustor that had parameters characteristic of modern GTPs. The article presents the results computed by the FlowVision software and the results of the experiments carried out on the test bench of the All-Russia Thermal Engineering Institute. The calculations and the tests were conducted under the following conditions: a flow rate of approximately 4.6 kg/s, a pressure to 450 kPa, an air temperature at the combustor inlet of approximately 400°C, the outlet temperature t 3 ≤ 1200°C, and natural gas as the fuel. The comparison of the simulated parameters with the experimental results underlies the constructed correlation dependence of the experimental NO x emission on the calculated parameter of nonuniform fuel concentration at the premixing zone outlet. The postulate about a weak dependence of the emission of NO x formed upon combustion of a perfectly mixed air-fuel mixture—when the methane concentration in air is constant at any point of the air-fuel mixture, i.e., constant in the mixture bulk—on the pressure in the combustor has been experimentally proven. The correctness and the practicability of the stationary mathematical model of the mixing process used to assess the NO x emission by the calculated amount of the air-fuel mixture generated in the premixing zone has been validated. This eliminates some difficulties that arise in the course of calculation of combustion and formation of NO x .

  1. Emission Characteristics of Gas-Fired Boilers based on Category-Specific Emission Factor from Field Measurements in Beijing, China

    Science.gov (United States)

    Itahashi, S.; Yan, X.; Song, G.; Yan, J.; Xue, Y.

    2017-12-01

    Gas-fired boilers will become the main stationary sources of NOx in Beijing. However, the knowledge of gas-fired boilers in Beijing is limited. In the present study, the emission characteristics of NOx, SO2, and CO from gas-fired boilers in Beijing were established using category-specific emission factors (EFs) from field measurements. In order to obtain category-specific EFs, boilers were classified through influence analysis. Factors such as combustion mode, boiler type, and installed capacity were considered critical for establishing EFs because they play significant roles in pollutant formation. The EFs for NOx, CO, and SO2 ranged from 1.42-6.86 g m-3, 0.05-0.67 g m-3 and 0.03-0.48 g m-3. The emissions of NOx, SO2, and CO for gas-fired boilers in Beijing were 11121 t, 468 t, and 222 t in 2014, respectively. The emissions were spatially allocated into grid cells with a resolution of 1 km × 1 km, and the results indicated that top emitters were in central Beijing. The uncertainties were quantified using a Monte Carlo simulation. The results indicated high uncertainties in CO (-157% to 154%) and SO2 (-127% to 182%) emissions, and relatively low uncertainties (-34% to 34%) in NOx emission. Furthermore, approximately 61.2% and 96.8% of the monitored chamber combustion boilers (CCBs) met the standard limits for NOx and SO2, respectively. Concerning NOx, low-NOx burners and NOx emission control measures are urgently needed for implementing of stricter standards. Adopting terminal control measures is unnecessary for SO2, although its concentration occasionally exceeds standard limits, because reduction of its concentration can be achieved thorough control of the sulfur content of natural gas at a stable low level. Furthermore, the atmospheric combustion boilers (ACBs) should be substituted with CCBs, because ACBs have a higher emission despite lower gross installed capacity. The results of this study will enable in understanding and controlling emissions from gas

  2. Economic feasibility of hydrogen enrichment for reducing NOx emissions from landfill gas power generation alternatives: A comparison of the levelized cost of electricity with present strategies

    International Nuclear Information System (INIS)

    Kornbluth, Kurt; Greenwood, Jason; Jordan, Eddie; McCaffrey, Zach; Erickson, Paul A.

    2012-01-01

    Based on recent research showing that hydrogen enrichment can lower NO x emissions from landfill gas combustion below future NO x emission control standards imposed by both federal and California state regulations, an investigation was performed to compare the levelized cost of electricity of this technology with other options. In this cost study, a lean-burn reciprocating engine with no after-treatment was the baseline case to compare six other landfill gas-to-energy projects. These cases include a lean burn engine with selective catalytic reduction after treatment, a lean-burn microturbine, and four variations on an ultra-lean-burn engine utilizing hydrogen enrichment with each case using a different method of hydrogen production. Only hydrogen enrichment with an in-stream autothermal fuel reformer was shown to be potentially cost-competitive with current strategies for reaching the NO x reduction target in IC engines. - Highlights: ► Levelized cost of electricity for hydrogen enriched combustion was compared. ► Various ultra-lean-burn engines and microturbines with hydrogen were analyzed. ► Combustion with an autothermal fuel reformer was potentially cost-competitive.

  3. Towards Ideal NOx and CO2 Emission Control Technology for Bio-Oils Combustion Energy System Using a Plasma-Chemical Hybrid Process

    International Nuclear Information System (INIS)

    Okubo, M; Fujishima, H; Yamato, Y; Kuroki, T; Tanaka, A; Otsuka, K

    2013-01-01

    A pilot-scale low-emission boiler system consisting of a bio-fuel boiler and plasma-chemical hybrid NO x removal system is investigated. This system can achieve carbon neutrality because the bio-fuel boiler uses waste vegetable oil as one of the fuels. The plasma-chemical hybrid NO x removal system has two processes: NO oxidation by ozone produced from plasma ozonizers and NO 2 removal using a Na 2 SO 3 chemical scrubber. Test demonstrations of the system are carried out for mixed oils (mixture of A-heavy oil and waste vegetable oil). Stable combustion is achieved for the mixed oil (20 – 50% waste vegetable oil). Properties of flue gas—e.g., O 2 , CO 2 and NO x —when firing mixed oils are nearly the same as those when firing heavy oil for an average flue gas flow rate of 1000 Nm 3 /h. NO x concentrations at the boiler outlet are 90 – 95 ppm. Furthermore, during a 300-min continuous operation when firing 20% mixed oil, NO x removal efficiency of more than 90% (less than 10 ppm NO x emission) is confirmed. In addition, the CO 2 reduction when heavy oil is replaced with waste vegetable oil is estimated. The system comparison is described between the plasma-chemical hybrid NO x removal and the conventional technology.

  4. Environmental Assessment for the Commercial Demonstration of the Low NOx Burner/Separated Over-Fire Air (LNB/SOFA) Integration System Emission Reduction Technology, Finney County, Kansas

    Energy Technology Data Exchange (ETDEWEB)

    n/a

    2003-03-11

    The U.S. Department of Energy (DOE) proposes to provide partial funding to the Sunflower Electric Power Corporation (Sunflower), to demonstrate the commercial application of Low-NO{sub x} Burner/Separated Over-Fire Air (LNB/SOFA) integration system to achieve NO{sub x} emission reduction to the level of 0.15 to 0.22 pounds per million British thermal units (lb/MM Btu). The proposed project station is Sunflower's 360 MW coal-fired generation station, Holcomb Unit No. 1 (Holcomb Station). The station, fueled by coal from Wyoming's Powder River Basin, is located near Garden City, in Finney County, Kansas. The period of performance is expected to last approximately 2 years. The Holcomb Station, Sunflower LNB/SOFA integrated system would be modified in three distinct phases to demonstrate the synergistic effect of layering NO{sub x} control technologies. Once modified, the station would demonstrate that a unit equipped with an existing low-NO{sub x} burner system can be retrofitted with a new separated over-fire air (SOFA) system, coal flow measurement and control, and enhanced combustion monitoring to achieve about 45 percent reduction in nitrogen oxides (NO{sub x}) emissions. The proposed project would demonstrate a technology alternative to Selective Catalytic Reduction (SCR) systems. While SCR does generally achieve high reductions in NO{sub x} emissions (from about 0.8 lb/MM to 0.12 lb/MM Btu), it does so at higher capital and operating cost, requires the extensive use of critical construction labor, requires longer periods of unit outage for deployment, and generally requires longer periods of time to complete shakedown and full-scale operation. Cost of the proposed project technology would be on the order of 15-25 percent of that for SCR, with consequential benefits derived from reductions in construction manpower requirements and periods of power outages. This proposed technology demonstration would generally be applicable to boilers using opposed

  5. Multiphase catalysts for selective reduction of NOx with hydrocarbons

    International Nuclear Information System (INIS)

    Maisuls, S.E.

    2000-01-01

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

  6. Emissões de CO2, NOX e N2O em solos sob diferentes cultivos na região do cerrado

    OpenAIRE

    Fernandes, Êrika Barretto

    2008-01-01

    O objetivo desse estudo foi avaliar as emissões de CO2, NO e N2O em Latossolos sob diferentes sistemas de cultivo em plantio direto na região do Cerrado. Os resultados são apresentados em três capítulos. O Capítulo 1 refere-se ao estudo dos efeitos de doses crescentes de fertilizante nitrogenado nos fluxos de gases traço ao longo do ciclo de cultivo de milho de sequeiro (nov.2004 a abr.2005). O experimento foi desenvolvido na Fazenda Dois J1 (município de Rio Verde, Goiás) em blocos ao acaso,...

  7. DEVELOPMENT OF A VALIDATED MODEL FOR USE IN MINIMIZING NOx EMISSIONS AND MAXIMIZING CARBON UTILIZATION WHEN CO-FIRING BIOMASS WITH COAL

    Energy Technology Data Exchange (ETDEWEB)

    Larry G. Felix; P. Vann Bush

    2002-04-30

    This is the sixth Quarterly Technical Report for DOE Cooperative Agreement No. DE-FC26-00NT40895. A statement of the project objectives is included in the Introduction of this report. Two additional biomass co-firing test burns were conducted during this quarter. In the first test (Test 10), up to 20% by weight dry hardwood sawdust and switchgrass was compiled with Galatia coal and injected through the dual-register burner. Galatia coal is a medium-sulfur Illinois Basin coal ({approx}1.0% S). The dual-register burner is a generic low-NO{sub x} burner that incorporates two independent wind boxes. In the second test (Test 11), regular ({approx}70% passing 200 mesh) and finely ground ({approx}90% passing 200 mesh) Pratt Seam coal was injected through the single-register burner to determine if coal grind affects NO{sub x} and unburned carbon emissions. The results of these tests are presented in this quarterly report. Significant progress has been made in implementing a modeling approach to combine reaction times and temperature distributions from computational fluid dynamic models of the pilot-scale combustion furnace with char burnout and chemical reaction kinetics to predict NO{sub x} emissions and unburned carbon levels in the furnace exhaust. No additional results of CFD modeling have been received as delivery of the Configurable Fireside Simulator is expected during the next quarter. Preparations are under way for continued pilot-scale combustion experiments with the single-register burner and a low-volatility bituminous coal. Some delays have been experienced in the acquisition and processing of biomass. Finally, a project review was held at the offices of Southern Research in Birmingham, on February 27, 2002.

  8. DEVELOPMENT OF A VALIDATED MODEL FOR USE IN MINIMIZING NOx EMISSIONS AND MAXIMIZING CARBON UTILIZATION WHEN CO-FIRING BIOMASS WITH COAL

    International Nuclear Information System (INIS)

    Larry G. Felix; P. Vann Bush

    2002-01-01

    This is the sixth Quarterly Technical Report for DOE Cooperative Agreement No. DE-FC26-00NT40895. A statement of the project objectives is included in the Introduction of this report. Two additional biomass co-firing test burns were conducted during this quarter. In the first test (Test 10), up to 20% by weight dry hardwood sawdust and switchgrass was compiled with Galatia coal and injected through the dual-register burner. Galatia coal is a medium-sulfur Illinois Basin coal ((approx)1.0% S). The dual-register burner is a generic low-NO(sub x) burner that incorporates two independent wind boxes. In the second test (Test 11), regular ((approx)70% passing 200 mesh) and finely ground ((approx)90% passing 200 mesh) Pratt Seam coal was injected through the single-register burner to determine if coal grind affects NO(sub x) and unburned carbon emissions. The results of these tests are presented in this quarterly report. Significant progress has been made in implementing a modeling approach to combine reaction times and temperature distributions from computational fluid dynamic models of the pilot-scale combustion furnace with char burnout and chemical reaction kinetics to predict NO(sub x) emissions and unburned carbon levels in the furnace exhaust. No additional results of CFD modeling have been received as delivery of the Configurable Fireside Simulator is expected during the next quarter. Preparations are under way for continued pilot-scale combustion experiments with the single-register burner and a low-volatility bituminous coal. Some delays have been experienced in the acquisition and processing of biomass. Finally, a project review was held at the offices of Southern Research in Birmingham, on February 27, 2002

  9. Biofuels, vehicle emissions, and urban air quality.

    Science.gov (United States)

    Wallington, Timothy J; Anderson, James E; Kurtz, Eric M; Tennison, Paul J

    2016-07-18

    Increased biofuel content in automotive fuels impacts vehicle tailpipe emissions via two mechanisms: fuel chemistry and engine calibration. Fuel chemistry effects are generally well recognized, while engine calibration effects are not. It is important that investigations of the impact of biofuels on vehicle emissions consider the impact of engine calibration effects and are conducted using vehicles designed to operate using such fuels. We report the results of emission measurements from a Ford F-350 fueled with either fossil diesel or a biodiesel surrogate (butyl nonanoate) and demonstrate the critical influence of engine calibration on NOx emissions. Using the production calibration the emissions of NOx were higher with the biodiesel fuel. Using an adjusted calibration (maintaining equivalent exhaust oxygen concentration to that of the fossil diesel at the same conditions by adjusting injected fuel quantities) the emissions of NOx were unchanged, or lower, with biodiesel fuel. For ethanol, a review of the literature data addressing the impact of ethanol blend levels (E0-E85) on emissions from gasoline light-duty vehicles in the U.S. is presented. The available data suggest that emissions of NOx, non-methane hydrocarbons, particulate matter (PM), and mobile source air toxics (compounds known, or suspected, to cause serious health impacts) from modern gasoline and diesel vehicles are not adversely affected by increased biofuel content over the range for which the vehicles are designed to operate. Future increases in biofuel content when accomplished in concert with changes in engine design and calibration for new vehicles should not result in problematic increases in emissions impacting urban air quality and may in fact facilitate future required emissions reductions. A systems perspective (fuel and vehicle) is needed to fully understand, and optimize, the benefits of biofuels when blended into gasoline and diesel.

  10. Evolution and application of a pseudo-multi-zone model for the prediction of NOx emissions from large-scale diesel engines at various operating conditions

    International Nuclear Information System (INIS)

    Savva, Nicholas S.; Hountalas, Dimitrios T.

    2014-01-01

    Highlights: • Development of a simplified simulation model for NO x formation during combustion. • Application of the proposed model on large-scale two and four-stroke diesel engines. • Experimental data from stationary and ship main and auxiliary engines were used. • The model captures the trend of NO x as engine power and fuel injection timing varies. • The model is recommended for research and practical use in maritime and power industry. - Abstract: Emissions regulations for heavy-duty diesel units used in maritime and power generation applications have become very strict the last years. Hence, the industry is enforced to limit specific gaseous and particulate emissions (NO x , SO x , CO x , PM and HC) depending on the regulations. Among numerous methods, simulation models are extensively used to support the development of techniques used for the control of emitted pollutants. This is very important for large-scale engines due to the extremely high cost of the experimental investigation resulting from the size of the engines and the test equipment involved. Beyond this, simulation models can also be used to support NO x monitoring, since on-board verification techniques are to become mandatory for the marine industry in the near future. Last but not least, simulation models can also be used for model-based control applications to support the operation of both in-cylinder and after-treatment techniques. Currently, the major controlled pollutant for both marine and stationary applications is NO x . For this reason, in the present work, authors focus on the development and application of a simplified NO x model with special emphasis on its ability to predict the effect of operating conditions on NO x for both two and four-stroke diesel engines. To accomplish this, an existing well validated simplified NO x model has been modified to enhance its physical background and applied on 16 different large-scale diesel engines utilizing 18 different sets of

  11. LOW NOX BURNER DEVELOPMENT

    Energy Technology Data Exchange (ETDEWEB)

    KRISHNA,C.R.; BUTCHER,T.

    2004-09-30

    The objective of the task is to develop concepts for ultra low NOx burners. One approach that has been tested previously uses internal recirculation of hot gases and the objective was to how to implement variable recirculation rates during burner operation. The second approach was to use fuel oil aerosolization (vaporization) and combustion in a porous medium in a manner similar to gas-fired radiant burners. This task is trying the second approach with the use of a somewhat novel, prototype system for aerosolization of the liquid fuel.

  12. DEVELOPMENT OF A VALIDATED MODEL FOR USE IN MINIMIZING NOx EMISSIONS AND MAXIMIZING CARBON UTILIZATION WHEN CO-FIRING BIOMASS WITH COAL

    Energy Technology Data Exchange (ETDEWEB)

    Larry G. Felix; P. Vann Bush

    2002-01-31

    This is the fifth Quarterly Technical Report for DOE Cooperative Agreement No. DE-FC26-00NT40895. A statement of the project objectives is included in the Introduction of this report. One additional biomass co-firing test burn was conducted during this quarter. In this test (Test 9), up to 20% by weight dry hardwood sawdust and switchgrass was injected through the center of the single-register burner with Jacobs Ranch coal. Jacobs Ranch coal is a low-sulfur Powder River Basin coal ({approx} 0.5% S). The results from Test 9 as well as for Test 8 (conducted late last quarter) are presented in this quarterly report. Significant progress has been made in implementing a modeling approach to combine reaction times and temperature distributions from computational fluid dynamic models of the pilot-scale combustion furnace with char burnout and chemical reaction kinetics to predict NO{sub x} emissions and unburned carbon levels in the furnace exhaust. Additional results of CFD modeling efforts have been received and preparations are under way for continued pilot-scale combustion experiments with the dual-register burner. Finally, a project review was held at NETL in Pittsburgh, on November 13, 2001.

  13. Nitrogen isotopes as indicators of NOx source contributions to atmospheric nitrate deposition across the midwestern and northeastern United States

    Science.gov (United States)

    Elliott, E.M.; Kendall, C.; Wankel, Scott D.; Burns, Douglas A.; Boyer, E.W.; Harlin, K.; Bain, D.J.; Butler, T.J.

    2007-01-01

    Global inputs of NOx are dominated by fossil fuel combustion from both stationary and vehicular sources and far exceed natural NOx sources. However, elucidating NOx sources to any given location remains a difficult challenge, despite the need for this information to develop sound regulatory and mitigation strategies. We present results from a regional-scale study of nitrogen isotopes (??15N) in wet nitrate deposition across 33 sites in the midwestern and northeastern U.S. We demonstrate that spatial variations in ??15N are strongly correlated with NOx emissions from surrounding stationary sources and additionally that ??15N is more strongly correlated with surrounding stationary source NOx emissions than pH, SO 42-, or NO3- concentrations. Although emission inventories indicate that vehicle emissions are the dominant NOx source in the eastern U.S., our results suggest that wet NO 3- deposition at sites in this study is strongly associated with NOx emissions from stationary sources. This suggests that large areas of the landscape potentially receive atmospheric NOy deposition inputs in excess of what one would infer from existing monitoring data alone. Moreover, we determined that spatial patterns in ??15N values are a robust indicator of stationary NOx contributions to wet NO3- deposition and hence a valuable complement to existing tools for assessing relationships between NO 3- deposition, regional emission inventories, and for evaluating progress toward NOx reduction goals. ?? 2007 American Chemical Society.

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

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  15. Measurement of nitrogen oxides (NOx) measurements in the Upper Troposphere and Lowermost Stratosphere within IAGOS - Instrument Performance and First Results

    Science.gov (United States)

    Berkes, Florian; Houben, Norbert; Pätz, Hans-Werner; Berg, Marcel; Blomel, Torben; Rupsch, Günther; Tappertzhofen, Marlon; Volz-Thomas, Andreas; Petzold, Andreas

    2016-04-01

    NOx (sum of NO and NO2) play a central role in atmospheric chemistry related to ozone and oxidation capacity (OH and NO3 radicals). The most important sources of NOx in the upper troposphere are lightning, transport from the boundary layer (combustion processes, from biomass burning, agriculture, and industry) and aircraft emissions. Measurements of NOx in the upper troposphere and lower stratosphere (UTLS) are rare but important for understanding the local photochemistry and for the assessment of the impact of aircraft on the budgets of greenhouse gases such as ozone and methane, and for validation of satellite observations of NO2. The European Research Infrastructure IAGOS (In-service Aircraft for a Global Observing System) operates on a global-scale monitoring system for atmospheric temperature, trace gases, aerosols and clouds in the UTLS at high spatial resolution by passenger aircrafts. The IAGOS NOx instrument is designed for the autonomous measurement of nitrogen oxides in the atmosphere. The measurement principle is based on the well-established chemiluminescence technique. For installation on commercial aircraft and for long deployment periods, the instrument is designed with one chemiluminescence channel and operably on a low measurement flow. Hence, measurements of NO and NO2 are made sequentially every 50 s. We present the instrument performance and first results from more than 200 flights in May to November 2015 over the North Atlantic. We focus on night time observations and discuss the occurrence and distribution of NO2 within the UTLS region.

  16. DEVELOPMENT OF A VALIDATED MODEL FOR USE IN MINIMIZING NOx EMISSIONS AND MAXIMIZING CARBON UTILIZATION WHEN CO-FIRING BIOMASS WITH COAL

    Energy Technology Data Exchange (ETDEWEB)

    Larry G. Felix; P. Vann Bush

    2002-07-01

    This is the seventh Quarterly Technical Report for DOE Cooperative Agreement No. DE-FC26-00NT40895. A statement of the project objectives is included in the Introduction of this report. Two additional biomass co-firing test burns were conducted during this quarter. In the first test (Test 12), up to 20% by weight dry hardwood sawdust and switchgrass was comilled with Galatia coal and injected through the single-register burner. Liquid ammonia was intermittently added to the primary air stream to increase fuel-bound nitrogen and simulate cofiring with chicken litter. Galatia coal is a medium-sulfur ({approx} 1.2% S), high chlorine ({approx}0.5%) Illinois Basin coal. In the second test (Test 13), up to 20% by weight dry hardwood sawdust and switchgrass was comilled with Jim Walters No.7 mine coal and injected through the single-register burner. Jim Walters No.7 coal is a low-volatility, low-sulfur ({approx} 0.7% S) Eastern bituminous coal. The results of these tests are presented in this quarterly report. Progress has continued to be made in implementing a modeling approach to combine reaction times and temperature distributions from computational fluid dynamic models of the pilot-scale combustion furnace with char burnout and chemical reaction kinetics to predict NO{sub x} emissions and unburned carbon levels in the furnace exhaust. The Configurable Fireside Simulator has been delivered from REI, Inc. and is being tested with exiting CFD solutions. Preparations are under way for a final pilot-scale combustion experiment using the single-register burner fired with comilled mixtures of Jim Walters No.7 low-volatility bituminous coal and switchgrass. Because of the delayed delivery of the Configurable Fireside Simulator, it is planned to ask for a no-cost time extension for the project until the end of this calendar year. Finally, a paper describing this project that included preliminary results from the first four cofiring tests was presented at the 12th European

  17. Dielectric and Radiative Properties of Sea Foam at Microwave Frequencies: Conceptual Understanding of Foam Emissivity

    Directory of Open Access Journals (Sweden)

    Peter W. Gaiser

    2012-04-01

    Full Text Available Foam fraction can be retrieved from space-based microwave radiometric data at frequencies from 1 to 37 GHz. The retrievals require modeling of ocean surface emissivity fully covered with sea foam. To model foam emissivity well, knowledge of foam properties, both mechanical and dielectric, is necessary because these control the radiative processes in foam. We present a physical description of foam dielectric properties obtained from the foam dielectric constant including foam skin depth; foam impedance; wavelength variations in foam thickness, roughness of foam layer interfaces with air and seawater; and foam scattering parameters such as size parameter, and refraction index. Using these, we analyze the scattering, absorption, reflection and transmission in foam and gain insights into why volume scattering in foam is weak; why the main absorption losses are confined to the wet portion of the foam; how the foam impedance matching provides the transmission of electromagnetic radiation in foam and maximizes the absorption; and what is the potential for surface scattering at the foam layers boundaries. We put all these elements together and offer a conceptual understanding for the high, black-body-like emissivity of foam floating on the sea surface. We also consider possible scattering regimes in foam.

  18. On-road emission characteristics of CNG-fueled bi-fuel taxis

    Science.gov (United States)

    Yao, Zhiliang; Cao, Xinyue; Shen, Xianbao; Zhang, Yingzhi; Wang, Xintong; He, Kebin

    2014-09-01

    To alleviate air pollution and lessen the petroleum demand from the motor vehicle sector in China, natural gas vehicles (NGVs) have been rapidly developed over the last several years. However, the understanding of the real-world emissions of NGVs is very limited. In this study, the emissions from 20 compressed-natural-gas-fueled bi-fuel taxis were measured using a portable emission measurement system (PEMS) under actual driving conditions in Yichang, China. The emission characteristics of the tested vehicles were analyzed, revealing that the average CO2, CO, HC and NOx emissions from the tested compressed-natural-gas (CNG) taxis under urban driving conditions were 1.6, 4.0, 2.0 and 0.98 times those under highway road conditions, respectively. The CO, HC and NOx emissions from Euro 3 CNG vehicles were approximately 40%, 55% and 44% lower than those from Euro 2 vehicles, respectively. Compared with the values for light-duty gasoline vehicles reported in the literature, the CO2 and CO emissions from the tested CNG taxis were clearly lower; however, significant increases in the HC and NOx emissions were observed. Finally, we normalized the emissions under the actual driving cycles of the entire test route to the New European Driving Cycle (NEDC)-based emissions using a VSP modes method developed by North Carolina State University. The simulated NEDC-based CO emissions from the tested CNG taxis were better than the corresponding emissions standards, whereas the simulated NEDC-based HC and NOx emissions greatly exceeded the standards. Thus, more attention should be paid to the emissions from CNG vehicles. As for the CNG-fueled bi-fuel taxis currently in use, the department of environmental protection should strengthen their inspection and supervision to reduce the emissions from these vehicles. The results of this study will be helpful in understanding and controlling emissions from CNG-fueled bi-fuel vehicles in China.

  19. Reduction of nitrogen oxides (NOx) by superalkalis

    Science.gov (United States)

    Srivastava, Ambrish Kumar

    2018-03-01

    NOx are major air pollutants, having negative impact on environment and consequently, human health. We propose here the single-electron reduction of NOx (x = 1, 2) using superalkalis. We study the interaction of NOx with FLi2, OLi3 and NLi4 superalkalis using density functional and single-point CCSD(T) calculations, which lead to stable superalkali-NOx ionic complexes with negatively charged NOx. This clearly reveals that the NOx can successfully be reduced to NOx- anion due to electron transfer from superalkalis. It has been also noticed that the size of superalkalis plays a crucial in the single-electron reduction of NOx.

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

    Science.gov (United States)

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

    2015-12-01

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

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

    Directory of Open Access Journals (Sweden)

    Lambeth J David

    2007-07-01

    canonical motifs, the B-loop, TM6-FAD, VXGPFG-motif, and extreme C-terminal regions were identified as important for Nox activity, as verified by mutational analysis. The presence of these non-canonical, but highly conserved regions suggests that all Nox/Duox may possess a common biological function remained in a long history of Nox/Duox evolution. Conclusion This report provides the first comprehensive analysis of the evolution and conserved functions of Nox and Duox family members, including identification of conserved amino acid residues. These results provide a guide for future structure-function studies and for understanding the evolution of biological functions of these enzymes.

  2. 40 CFR 60.4340 - How do I demonstrate continuous compliance for NOX if I do not use water or steam injection?

    Science.gov (United States)

    2010-07-01

    ... compliance for NOX if I do not use water or steam injection? 60.4340 Section 60.4340 Protection of....4340 How do I demonstrate continuous compliance for NOX if I do not use water or steam injection? (a) If you are not using water or steam injection to control NOX emissions, you must perform annual...

  3. Regulation of denitrification at the cellular level: a clue to the understanding of N2O emissions from soils

    Science.gov (United States)

    Bakken, Lars R.; Bergaust, Linda; Liu, Binbin; Frostegård, Åsa

    2012-01-01

    Denitrifying prokaryotes use NOx as terminal electron acceptors in response to oxygen depletion. The process emits a mixture of NO, N2O and N2, depending on the relative activity of the enzymes catalysing the stepwise reduction of NO3− to N2O and finally to N2. Cultured denitrifying prokaryotes show characteristic transient accumulation of NO2−, NO and N2O during transition from oxic to anoxic respiration, when tested under standardized conditions, but this character appears unrelated to phylogeny. Thus, although the denitrifying community of soils may differ in their propensity to emit N2O, it may be difficult to predict such characteristics by analysis of the community composition. A common feature of strains tested in our laboratory is that the relative amounts of N2O produced (N2O/(N2+N2O) product ratio) is correlated with acidity, apparently owing to interference with the assembly of the enzyme N2O reductase. The same phenomenon was demonstrated for soils and microbial communities extracted from soils. Liming could be a way to reduce N2O emissions, but needs verification by field experiments. More sophisticated ways to reduce emissions may emerge in the future as we learn more about the regulation of denitrification at the cellular level. PMID:22451108

  4. 40 CFR 76.12 - Phase I NOX compliance extension.

    Science.gov (United States)

    2010-07-01

    ....12 Section 76.12 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... reliability problems are due substantially to NOX emission control system installation and availability; or... outage. (iii) Fuel and energy balance summaries and power and other consumption requirements (including...

  5. NOX5 in Human Spermatozoa

    Science.gov (United States)

    Musset, Boris; Clark, Robert A.; DeCoursey, Thomas E.; Petheo, Gabor L.; Geiszt, Miklos; Chen, Yumin; Cornell, John E.; Eddy, Carlton A.; Brzyski, Robert G.; El Jamali, Amina

    2012-01-01

    Physiological and pathological processes in spermatozoa involve the production of reactive oxygen species (ROS), but the identity of the ROS-producing enzyme system(s) remains a matter of speculation. We provide the first evidence that NOX5 NADPH oxidase is expressed and functions in human spermatozoa. Immunofluorescence microscopy detected NOX5 protein in both the flagella/neck region and the acrosome. Functionally, spermatozoa exposed to calcium ionophore, phorbol ester, or H2O2 exhibited superoxide anion production, which was blocked by addition of superoxide dismutase, a Ca2+ chelator, or inhibitors of either flavoprotein oxidases (diphenylene iododonium) or NOX enzymes (GKT136901). Consistent with our previous overexpression studies, we found that H2O2-induced superoxide production by primary sperm cells was mediated by the non-receptor tyrosine kinase c-Abl. Moreover, the HV1 proton channel, which was recently implicated in spermatozoa motility, was required for optimal superoxide production by spermatozoa. Immunoprecipitation experiments suggested an interaction among NOX5, c-Abl, and HV1. H2O2 treatment increased the proportion of motile sperm in a NOX5-dependent manner. Statistical analyses showed a pH-dependent correlation between superoxide production and enhanced sperm motility. Collectively, our findings show that NOX5 is a major source of ROS in human spermatozoa and indicate a role for NOX5-dependent ROS generation in human spermatozoa motility. PMID:22291013

  6. Low Temperature DeNOx Technologies for Power and Waste Incineration Plants

    DEFF Research Database (Denmark)

    Jakobsen, Peter Westergaard

    drawn particular interest over the past decade is biomass and municipal waste. While the CO2 emissions are decreased by a transition to these fuels, other problems are caused by it. Potassium present in many of the alternative fuels lead to severe deactivation of the catalyst used for NOx abatement......Formation of NOx is inevitable during high temperature combustion processes in air. NOx is of increasing environmental concern due to its participation in detrimental photochemical reactions, which lead to ozone layer depletion. NOx emissions also cause acid rain, contributes to smog formation...... and induces respiratory diseases in humans. There is no doubt that anthropogenic effects are contributing to the global climate change. The largest contributor to anthropogenic greenhouse gas emissions is CO2. been of great interest as a method to decrease global CO2 emissions. Some of the fuels that have...

  7. The NOx Budget Trading Program: A Collaborative, Innovative Approach to Solving a Regional Air Pollution Problem

    Science.gov (United States)

    This article examines the development and implementation of the NOx Budget Trading Program (NBP) and the lessons the Environmental Protection Agency has learned from this seasonal emissions cap-and-trade program.

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

    International Nuclear Information System (INIS)

    Mannan, M.A.

    2009-01-01

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

  9. Improvement study for the dry-low-NOx hydrogen micromix combustion technology

    OpenAIRE

    A. Haj Ayed; K. Kusterer; H.H.-W. Funke; J. Keinz; C. Striegan; D. Bohn

    2015-01-01

    The dry-low-NOx (DLN) micromix combustion principle is developed for the low emission combustion of hydrogen in an industrial gas turbine APU GTCP 36-300. The further decrease of NOx emissions along a wider operation range with pure hydrogen supports the introduction of the micromix technology to industrial applications. Experimental and numerical studies show the successful advance of the DLN micromix combustion to extended DLN operation range. The impact of the hydrogen fuel properties on t...

  10. 40 CFR 97.12 - Changing NOX authorized account representative and alternate NOX authorized account...

    Science.gov (United States)

    2010-07-01

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

  11. The selectivity of Vibrio cholerae H-NOX for gaseous ligands follows the "sliding scale rule" hypothesis. Ligand interactions with both ferrous and ferric Vc H-NOX.

    Science.gov (United States)

    Wu, Gang; Liu, Wen; Berka, Vladimir; Tsai, Ah-lim

    2013-12-31

    Vc H-NOX (or VCA0720) is an H-NOX (heme-nitric oxide and oxygen binding) protein from facultative aerobic bacterium Vibrio cholerae. It shares significant sequence homology with soluble guanylyl cyclase (sGC), a NO sensor protein commonly found in animals. Similar to sGC, Vc H-NOX binds strongly to NO and CO with affinities of 0.27 nM and 0.77 μM, respectively, but weakly to O2. When positioned on a "sliding scale" plot [Tsai, A.-l., et al. (2012) Biochemistry 51, 172-186], the line connecting log K(D)(NO) and log K(D)(CO) of Vc H-NOX can almost be superimposed with that of Ns H-NOX. Therefore, the measured affinities and kinetic parameters of gaseous ligands to Vc H-NOX provide more evidence to validate the "sliding scale rule" hypothesis. Like sGC, Vc H-NOX binds NO in multiple steps, forming first a six-coordinate heme-NO complex at a rate of 1.1 × 10(9) M(-1) s(-1), and then converts to a five-coordinate heme-NO complex at a rate that is also dependent on NO concentration. Although the formation of oxyferrous Vc H-NOX cannot be detected at a normal atmospheric oxygen level, ferrous Vc H-NOX is oxidized to the ferric form at a rate of 0.06 s(-1) when mixed with O2. Ferric Vc H-NOX exists as a mixture of high- and low-spin states and is influenced by binding to different ligands. Characterization of both ferric and ferrous Vc H-NOX and their complexes with various ligands lays the foundation for understanding the possible dual roles in gas and redox sensing of Vc H-NOX.

  12. Regulation of Nox enzymes expression in vascular pathophysiology: Focusing on transcription factors and epigenetic mechanisms.

    Science.gov (United States)

    Manea, Simona-Adriana; Constantin, Alina; Manda, Gina; Sasson, Shlomo; Manea, Adrian

    2015-08-01

    NADPH oxidases (Nox) represent a family of hetero-oligomeric enzymes whose exclusive biological function is the generation of reactive oxygen species (ROS). Nox-derived ROS are essential modulators of signal transduction pathways that control key physiological activities such as cell growth, proliferation, migration, differentiation, and apoptosis, immune responses, and biochemical pathways. Enhanced formation of Nox-derived ROS, which is generally associated with the up-regulation of different Nox subtypes, has been established in various pathologies, namely cardiovascular diseases, diabetes, obesity, cancer, and neurodegeneration. The detrimental effects of Nox-derived ROS are related to alterations in cell signalling and/or direct irreversible oxidative damage of nucleic acids, proteins, carbohydrates, and lipids. Thus, understanding of transcriptional regulation mechanisms of Nox enzymes have been extensively investigated in an attempt to find ways to counteract the excessive formation of Nox-derived ROS in various pathological states. Despite the numerous existing data, the molecular pathways responsible for Nox up-regulation are not completely understood. This review article summarizes some of the recent advances and concepts related to the regulation of Nox expression in the vascular pathophysiology. It highlights the role of transcription factors and epigenetic mechanisms in this process. Identification of the signalling molecules involved in Nox up-regulation, which is associated with the onset and development of cardiovascular dysfunction may contribute to the development of novel strategies for the treatment of cardiovascular diseases. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  13. Biosphere-Atmosphere Exchange of NOx and O3 in Central Amazon

    Science.gov (United States)

    Wiedemann, K. T.; Swofsy, S. C.; Munger, J. W.; Saleska, S. R.; Rizzo, L. V.; Silva Campos, K.

    2017-12-01

    The primary source of atmospheric OH is the photolysis of O3 in the presence of water vapor. NOx gases are the main precursors of O3 and OH. In NOx-rich environments that have both high humidity and high solar radiation, OH concentrations are enhanced, making tropical forests dominant in global oxidation of long lived gases. The Amazon rain forest has a unique combination of vegetation with diverse characteristics, climate, and a dynamic land use, factors that altogether govern the emission and fate of trace gases, particle formation and atmospheric chemistry. Understanding the interactions among the mechanisms that govern local precursor emissions will lead to a better description of the local atmospheric chemistry and its global impacts. As part of the GoAmazon project, an array of complementary measurements was conducted in a research site in central Amazon, near Santarem (PA, Brazil), inside the Tapajos National Forest. The research site is surrounded by intact rain forest in a 6km radius, and a 45m canopy. The 67m tower was assembled in the site in 2001 for flux measurements (CO2 and H2O). In mid 2014 additional instrumentation were added, measuring NOx, O3, CH4, and SO2 fluxes and profiles. The low concentrations of SO2 (up to 0.1ppb during the peak of the dry season), and a small vertical gradient, suggest the predominance of biogenic sources. O3 show no significant seasonality between the daytime and nighttime vertical profiles, but occasional nighttime high concentrations for levels below canopy were observed. Hourly ozone fluxes suggest a production of O3 under canopy. NO soil emissions are indicated by concentrations in the ppb range for lower profile levels, decreasing to a few hundreds ppt above the canopy, and emission rates of NO from Amazonian soils may be higher than expected from earlier measurements. Daytime data indicate that not all of this NOx escapes to the atmosphere, however. Fluxes of NO average 133x109 molec cm-2 s-1, a factor of 4 higher

  14. NOx Effects on Photochemical Aging of Urban Wet Particles

    Science.gov (United States)

    Lim, Y. B.; Seo, J.; Kim, J. Y.; Turpin, B. J.

    2017-12-01

    Aqueous chemistry in aerosol liquid water (ALW) has been considered an important pathway of particle formation, which is expected to improve current models; however, little is known about NOx effects on aqueous chemistry in wet urban particulate matter (PM). Here we show photochemical aging of wet aerosols at modest urban conditions conducted in a smog chamber and provide atmospheric evidence of these chamber reactions. At high relative humidity, HNO3, the main sink of photochemistry of NOx, initiates water uptake into aerosols and ALW in turn facilitates aqueous chemistry. The hygroscopic growth was significant, and aqueous chemistry led to mainly non-radical products, such as organonitrates and oligomers. This multiphase chemistry contributes to particle aging during a haze event in Seoul, a megacity in East Asia. PM2.5 at Seoul, a downwind site at high NOx conditions, and reference PM2.5 at Deokjeok Island, an upwind site that has no emission source, during winter including the haze period were analyzed. Chemical components of Seoul haze particles can be explained by photochemical aging of transported particles in the presence of NOx. East Asian megacities including Seoul suffer from high concentration particles, yet the formation is poorly understood. Our finding of chemical aging and secondary formation highlights the importance of multiphase reactions, including gas-phase photochemistry at high NOx and aqueous chemistry in ALW, which need to be incorporated into air quality models to improve predictions for public health.

  15. The NOx Budget. Market-based control of tropospheric ozone in the northeastern United States

    International Nuclear Information System (INIS)

    Farrell, Alex; Carter, Robert; Raufer, Roger

    1999-01-01

    The NOx Budget is a marketable emissions allowance system currently being adopted by states in the Northeastern US to reduce tropospheric ozone concentrations to healthful levels in a cost-effective manner. Oxides of nitrogen (NOx) are currently regulated within the existing Command and Control (CAC) framework. The introduction of a market-based approach will further reduce emissions, but will not resolve all regulatory uncertainties. These implementation concerns are identified and discussed. Cost savings and emissions reductions patterns which will arise under several different scenarios are determined through the use of a dynamic, relaxed mixed-integer linear programming model of the NOx allowance market. Like other market-based pollution control programs, the NOx Budget is found to be more efficient than CAC options. Restrictions on the market designed to address perceived flaws are found to be expensive but ineffectual

  16. NOX Modifiers-Just a Step Away from Application in the Therapy of Airway Inflammation?

    Science.gov (United States)

    Wieczfinska, Joanna; Sokolowska, Milena; Pawliczak, Rafal

    2015-08-10

    NADPH oxidase (NOX) enzymes, which are widely expressed in different airway cell types, not only contribute to the maintenance of physiological processes in the airways but also participate in the pathogenesis of many acute and chronic diseases. Therefore, the understanding of NOX isoform regulation, expression, and the manner of their potent inhibition might lead to effective therapeutic approaches. The study of the role of NADPH oxidases family in airway physiology and pathophysiology should be considered as a work in progress. While key questions still remain unresolved, there is significant progress in terms of our understanding of NOX importance in airway diseases as well as a more efficient way of using NOX modifiers in human settings. Agents that modify the activity of NADPH enzyme components would be considered useful tools in the treatment of various airway diseases. Nevertheless, profound knowledge of airway pathology, as well as the mechanisms of NOX regulation is needed to develop potent but safe NOX modifiers. Many compounds seem to be promising candidates for development into useful therapeutic agents, but their clinical potential is yet to be demonstrated. Further analysis of basic mechanisms in human settings, high-throughput compound scanning, clinical trials with new and existing molecules, and the development of new drug delivery approaches are the main directions of future studies on NOX modifiers. In this article, we discuss the current knowledge with regard to NOX isoform expression and regulation in airway inflammatory diseases as well as the aptitudes and therapeutic potential of NOX modifiers.

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

    Science.gov (United States)

    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.

  18. Understanding the nature of methane emission from rice ecosystems as basis of mitigation strategies

    Energy Technology Data Exchange (ETDEWEB)

    Buendia, L.V.; Neue, H.U.; Wassmann, R. [International Rice Research Institute, Laguna (Philippines)] [and others

    1996-12-31

    Methane is considered as an important Greenhouse gas and rice fields are one of the major atmospheric methane sources. The paper aims to develop sampling strategies and formulate mitigation options based on diel (day and night) and seasonal pattern of methane emission. The study was conducted in 4 countries to measure methane flux using an automatic closed chamber system. A 24-hour bihourly methane emissions were continuously obtained during the whole growing season. Daily and seasonal pattern of methane fluxes from different rice ecosystems were evaluated. Diel pattern of methane emission from irrigated rice fields, in all sites, displayed similar pattern from planting to flowering. Fluxes at 0600, 1200, and 1800 h were important components of the total diel flux. A proposed sampling frequency to accurately estimate methane emission within the growing season was designed based on the magnitude of daily flux variation. Total methane emission from different ecosystems follow the order: deepwater rice > irrigated rice > rainfed rice. Application of pig manure increased total emission by 10 times of that without manure. Green manure application increased emission by 49% of that applied only with inorganic fertilizer. Removal of floodwater at 10 DAP and 35 DAP, within a period of 4 days, inhibited production and emission of methane. The level of variation in daily methane emission and seasonal emission pattern provides useful information for accurate determination of methane fluxes. Characterization of seasonal emission pattern as to ecologies, fertilizer amendments, and water management gives an idea of where to focus mitigation strategies for sustainable rice production.

  19. Application of the NOx Reaction Model for Development of Low-NOx Combustion Technology for Pulverized Coals by Using the Gas Phase Stoichiometric Ratio Index

    Directory of Open Access Journals (Sweden)

    Kenji Yamamoto

    2011-03-01

    Full Text Available We previously proposed the gas phase stoichiometric ratio (SRgas as an index to evaluate NOx concentration in fuel-rich flames. The SRgas index was defined as the amount of fuel required for stoichiometric combustion/amount of gasified fuel, where the amount of gasified fuel was the amount of fuel which had been released to the gas phase by pyrolysis, oxidation and gasification reactions. In the present study we found that SRgas was a good index to consider the gas phase reaction mechanism in fuel-rich pulverized coal flames. When SRgas < 1.0, NOx concentration was strongly influenced by the SRgas value. NOx concentration was also calculated by using a reaction model. The model was verified for various coals, particle diameters, reaction times, and initial oxygen concentrations. The most important reactions were gas phase NOx reduction reactions by hydrocarbons. The hydrocarbon concentration was estimated based on SRgas. We also investigated the ratio as an index to develop a new low-NOx combustion technology for pulverized coals. We examined the relation between local SRgas distribution in the fuel-rich region in the low-NOx flame and NOx emissions at the furnace exit, by varying burner structures. The relationship between local SRgas value and local NOx concentration was also examined. When a low-NOx type burner was used, the value of SRgas in the flame was readily decreased. When the local SRgas value was the same, it was difficult to influence the local NOx concentration by changing the burner structure. For staged combustion, the most important item was to design the burner structure and arrangement so that SRgas could be lowered as much as possible just before mixing with staged air.

  20. Modeling of NOx Destruction Options for INEEL Sodium-Bearing Waste Vitrification

    Energy Technology Data Exchange (ETDEWEB)

    Wood, Richard Arthur

    2001-09-01

    Off-gas NOx concentrations in the range of 1-5 mol% are expected as a result of the proposed vitrification of sodium-bearing waste at the Idaho National Engineering and Environmental Laboratory. An existing kinetic model for staged combustion (originally developed for NOx abatement from the calcination process) was updated for application to vitrification offgas. In addition, two new kinetic models were developed to assess the feasibility of using selective non-catalytic reduction (SNCR) or high-temperature alone for NOx abatement. Each of the models was developed using the Chemkin code. Results indicate that SNCR is a viable option, reducing NOx levels to below 1000 ppmv. In addition, SNCR may be capable of simultaneously reducing CO emissions to below 100 ppmv. Results for using high-temperature alone were not as promising, indicating that a minimum NOx concentration of 3950 ppmv is achievable at 3344°F.

  1. Exploring the Production of NOx by Lightning and Its Impact on Tropospheric Ozone

    Science.gov (United States)

    Gillani, Noor; Koshak, William; Biazar, Arastoo; Doty, Kevin; Mahon, Robert; Newchurch, Michael; Byun, Daewon; Emmons, Louisa

    2006-01-01

    Our quantitative understanding of free tropospheric (FT) chemistry is quite poor. State-of-the-art regional air quality models (e.g., US EPA's CMAQ) perform very poorly in simulating FT chemistry, with Uniform ozone around 70 ppb throughout the FT in summer, while ozonesonde data show much higher levels of ozone and much spatial-temporal structure. Such models completely neglect lightning-NOx (LNOx) emissions (the most significant source of NOx in the FT), and also contain large uncertainties in the specifications of intercontinental transport, stratosphere-troposphere exchange (STE) and PBLFT exchange (PFTE). Global air chemistry models include LNOx, but in very crude fashion, with the frequency and distribution of lightning being based on modeled cloud parameters (hence large uncertainty), lightning energetics being assumed to be constant for all flashes (literature value, while in reality there is at least a two-orders of magnitude variability from flash-to-flash), and the production of NOx in the surrounding heated air, per Joule of heating, being assumed to be constant also (literature value, while in fact it is a non-linear function of the dissipated heat and local air density, p). This situation is commonly blamed on paucity of pertinent observational data, but for the USA, there is now a wealth of surface- and satellite-based data of lightning available to permit much improved observation-based estimation of LNOx emissions. In the FT, such NOx has a long residence time, and also the ozone production efficiency from NOx there is considerably higher than in the PBL. It is, therefore, of critical importance in FT chemistry. This paper will describe the approach and data products of an ongoing NSSTC project aimed at a much-improved quantification of not only LNOx production on the scale of continental USA based on local and regional lightning observations, but also of intercontinental transport, STE and PFTE, all in upgraded simulations of tropospheric

  2. Technical assessment of NOx generation from vitrification process of spent ion-exchange resin

    International Nuclear Information System (INIS)

    Park, S. C.; Yang, K. H.; Kim, H. S.; Lu, C. S.; Lee, K. H.; Hwnag, T. W.; Shin, S. W.

    2001-01-01

    When the radioactive spent ion-exchange resin is being treated in vitrification system, due to the nitrogen in the anion exchange resin media and the nitrogen in air inleaked to the system, the nitrogen oxide (NOx) is generated from both glass melter and the second combustion chamber among the unit-processes in the vitrification plant. The NOx is very hazardous to environment and to human health the emission limit of NOx is regulated very severely. In this study, the NOx generation characteristics are technically analyzed based on the demonstration-test resultes conducted recently by burning simulated spent resin. When burning 30kg/h of simulated resin in CCM under 50% of excess the theoretically needed, the NOx was measured as between 3000 ∼ 3500ppm after 1h of transient test period. And when only the propane is burning in PCC without resin burning in CCM, the concentration of NOx exceeded the detectable limit(4000 ppm) of PGA. The former and the latter were considered as the fuel NOx and the thermal NOx respectively

  3. 40 CFR 86.1861-04 - How do the Tier 2 and interim non-Tier 2 NOX averaging, banking and trading programs work?

    Science.gov (United States)

    2010-07-01

    ... average NOX emissions exceeds the 0.07 g/mile standard must complete the calculation at paragraph (b) of... NOX emissions is less than or equal to the 0.07 g/mile standard must complete the calculation in.... Credits are earned on the last day of the model year. Before trading or carrying over credits to the next...

  4. Emissions from Plug-in Hybrid Electric Vehicle (PHEV) During Real World Driving Under Various Weather Conditions

    Science.gov (United States)

    2018-02-02

    Exposure to particulate matter (PM) and pollutant gas (NOx) is associated with increased cardiopulmonary morbidity and mortality. Mobile source emissions contribute to PM and NOx emissions significantly in urban areas. Hybrid Electric Vehicles (HEVs)...

  5. Final Rule for Control of Air Pollution from Aircraft and Aircraft Engines: Emission Standards and Test Procedures

    Science.gov (United States)

    EPA is amending the existing emission standards for oxides of nitrogen (NOx) for new commercial aircraft engines. These standards are equivalent to the NOx emission standards of the United Nations International Civil Aviation Organization (ICAO).

  6. 40 CFR 52.2237 - NOX RACT and NOX conformity exemption.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false NOX RACT and NOX conformity exemption... PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Tennessee § 52.2237 NOX RACT and NOX conformity exemption. Approval. EPA is approving the section 182(f) oxides of nitrogen...

  7. 40 CFR 97.188 - CAIR NOX allowance allocations to CAIR NOX opt-in units.

    Science.gov (United States)

    2010-07-01

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

  8. 40 CFR 96.52 - NOX Allowance Tracking System responsibilities of NOX authorized account representative.

    Science.gov (United States)

    2010-07-01

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

  9. 40 CFR 96.188 - CAIR NOX allowance allocations to CAIR NOX opt-in units.

    Science.gov (United States)

    2010-07-01

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

  10. Understanding the issues around quantifying GHG emissions in the financial sector

    International Nuclear Information System (INIS)

    Jacono, Caline; Poivet, Romain; Havette, Didier; Maille, Catherine; Jaubert, Nathalie; Grandjean, Alain; Cottenceau, Jean-Baptiste; Finidori, Esther; Le Teno, Helene; Cochard, Eric; Sanchez, Thomas; Michaux, Elisabeth; Courcier, Jerome; Marie Lapalle; Guez, Herve; Mia, Ladislas; Agnes Guiral; Martinez, Emmanuel; Rose, Antoine; Breton, Herve; Meyssonier, Guillaume; Arndt, Matthew; Saichs, Nancy; Desfosses, Philippe; Bonnet, Olivier; Rouchon, Jean-Philippe; Smart, Lauren; Lenoel, Benjamin; Dupre, Stanislas; Chenet, Hugues; Lavaud, Patricia; Laviale, Michel; Lucas-Leclin, Valery; Bernasconi, Maxime; Merlin, Alexis; Delettang, Catherine; Gerardi, Anne

    2016-01-01

    In the face of climate change, the financial sector shows a need to have access to methods and tools for quantifying GHG emissions. This guide proposes to address multiple needs of financial institutions (Investment banks, insurers, retail bank, commercial bank, asset managers...) in terms of financed emissions quantification. It meets two objectives: Make formal methodological recommendations for financial institutions about their operating related emissions, and propose methodological recommendations to quantify financed emissions (Scop3 - Poste 15 'Investments'). The guide is divided in three parts. Volume 1 gives background, identifies sectorial challenges related to climate change and offers an overview of the main existing quantification methods and tools. Volume 2 offers practical and operational guidance for estimating emissions from organisation's back-office functions into the financial sector. Volume 3 (through case studies) offers methodological information to quantify the financed emissions through a 'top-down' approach, with an 'excel' tool to calculate emission factors related to this method

  11. NOx Pollution Analysis for a Sulfur Recovery Unit Thermal Reactor

    Science.gov (United States)

    Yeh, Chun-Lang

    2017-12-01

    A sulfur recovery unit (SRU) thermal reactor is the most important equipment in a sulfur plant. It is negatively affected by high temperature operations. In this paper, NOx emissions from the SRU thermal reactors are simulated. Both the prototype thermal reactor and its modifications, including changing fuel mass fraction, changing inlet air quantity, changing inlet oxygen mole fraction, and changing burner geometry, are analyzed to investigate their influences on NOx emissions. In respect of the fuel mass fraction, the simulation results show that the highest NO emission occurs at a zone 1 fuel mass fraction of 0.375, around which the reactor maximum temperature and the zone 1 average temperature reach maximum values. Concerning the inlet air quantity, the highest NO emission occurs when the inlet air quantity is 2.4 times the designed inlet air quantity. This is very close to the inlet air quantity at which the maximum average temperature occurs. Regarding the inlet oxygen mole fraction, the NO emission increases as the inlet oxygen mole fraction increases. With regard to the burner geometry, the NO emission increases as the clearance of the burner acid gas tip increases. In addition, the NO emission increases as the swirling strength increases.

  12. Selective NOx Recirculation for Stationary Lean-Burn Natural Gas Engines

    Energy Technology Data Exchange (ETDEWEB)

    Nigel N. Clark

    2006-12-31

    Nitric oxide (NO) and nitrogen dioxide (NO2) generated by internal combustion (IC) engines are implicated in adverse environmental and health effects. Even though lean-burn natural gas engines have traditionally emitted lower oxides of nitrogen (NOx) emissions compared to their diesel counterparts, natural gas engines are being further challenged to reduce NOx emissions to 0.1 g/bhp-hr. The Selective NOx Recirculation (SNR) approach for NOx reduction involves cooling the engine exhaust gas and then adsorbing the NOx from the exhaust stream, followed by the periodic desorption of NOx. By sending the desorbed NOx back into the intake and through the engine, a percentage of the NOx can be decomposed during the combustion process. SNR technology has the support of the Department of Energy (DOE), under the Advanced Reciprocating Engine Systems (ARES) program to reduce NOx emissions to under 0.1 g/bhp-hr from stationary natural gas engines by 2010. The NO decomposition phenomenon was studied using two Cummins L10G natural gas fueled spark-ignited (SI) engines in three experimental campaigns. It was observed that the air/fuel ratio ({lambda}), injected NO quantity, added exhaust gas recirculation (EGR) percentage, and engine operating points affected NOx decomposition rates within the engine. Chemical kinetic model predictions using the software package CHEMKIN were performed to relate the experimental data with established rate and equilibrium models. The model was used to predict NO decomposition during lean-burn, stoichiometric burn, and slightly rich-burn cases with added EGR. NOx decomposition rates were estimated from the model to be from 35 to 42% for the lean-burn cases and from 50 to 70% for the rich-burn cases. The modeling results provided an insight as to how to maximize NOx decomposition rates for the experimental engine. Results from this experiment along with chemical kinetic modeling solutions prompted the investigation of rich-burn operating conditions

  13. Ecodriving and carbon footprinting : understanding how public education can reduce greenhouse gas emissions and fuel use.

    Science.gov (United States)

    2012-04-01

    Ecodriving is a collection of changes to driving behavior and vehicle maintenance designed to impact fuel consumption and greenhouse gas (GHG) emissions in existing vehicles. Because of its promise to improve fuel economy within the existing fleet, e...

  14. Dielectric and Radiative Properties of Sea Foam at Microwave Frequencies: Conceptual Understanding of Foam Emissivity

    OpenAIRE

    Peter W. Gaiser; Magdalena D. Anguelova

    2012-01-01

    Foam fraction can be retrieved from space-based microwave radiometric data at frequencies from 1 to 37 GHz. The retrievals require modeling of ocean surface emissivity fully covered with sea foam. To model foam emissivity well, knowledge of foam properties, both mechanical and dielectric, is necessary because these control the radiative processes in foam. We present a physical description of foam dielectric properties obtained from the foam dielectric constant including foam skin depth; foam ...

  15. NOx cycle and the tropospheric ozone isotope anomaly: an experimental investigation

    Science.gov (United States)

    Michalski, G.; Bhattacharya, S. K.; Girsch, G.

    2014-05-01

    The oxygen isotope composition of nitrogen oxides (NOx) in the atmosphere is a useful tool for understanding the oxidation of NOx into nitric acid / nitrate in the atmosphere. A set of experiments was conducted to examine change in isotopic composition of NOx due to NOx-O2-O3 photochemical cycling. At low NOx / O2 mixing ratios, NOx became progressively and nearly equally enriched in 17O and 18O over time until it reached a steady state with Δ17O values of 39.3 ± 1.9‰ and δ18O values of 84.2 ± 4‰, relative to the isotopic composition of the initial O2 gas. As the mixing ratios were increased, the isotopic enrichments were suppressed by isotopic exchange between O atoms, O2, and NOx. A kinetic model was developed to simulate the observed data and it showed that the isotope effects occurring during O3 formation play a dominant role in controlling NOx isotopes and, in addition, secondary kinetic isotope effects or isotope exchange reactions are also important during NOx cycling. The data and model were consistent with previous studies which showed that the NO + O3 reactions occur mainly via the transfer of the terminal atoms of O3. The model predicts that under tropospheric concentrations of NOx and O3, the timescale of NOx-O3 isotopic equilibrium ranges from hours (for ppbv NOx / O2 mixing ratios) to days (for pptv mixing ratios) and yields steady state Δ17O and δ18O values of 45‰ and 117‰ respectively (relative to Vienna Standard Mean Ocean Water (VSMOW)) in both cases. Under atmospheric conditions when O3 has high concentrations, the equilibrium between NOx and O3 should occur rapidly (h) but this equilibrium cannot be reached during polar winters and/or nights if the NOx conversion to HNO3 is faster. The experimentally derived rate coefficients can be used to model the major NOx-O3 isotopologue reactions at various pressures and in isotope modeling of tropospheric nitrate.

  16. The simultaneous emission of two nucleons, an understanding and new predictions

    International Nuclear Information System (INIS)

    Chavez L, E.; Barron, P.L.; Hernandez de la P, L.; Huerta H, A.; Ibanes S, A.; Macias P, R.; Moreno, E.; Hernandez de la P, L.; Huerta H, A.; Ibanes S, A.; Liang, J.F.; Macias P, R.; Moreno, E.; Ortiz, M.E.; Murillo, G.; Policroniades, R.; Varela, A; Beene, J.R.; Galindo U, A.; Gomez del Campo, J.; Gross, C.J.; Halbert, M.L.; Paul, S.D; Stracener, D.W.; Shapira, D.; Varner, R.L.

    2002-01-01

    After a long standing search of over 40 years, the simultaneous emission of two protons was discovered. An excited state in a light nuclei ( 18 Ne), not a ground state, was identified as the first state to have such decay property. In this work, we review that discovery, discuss the concept of simultaneity and propose a simple analysis in terms of the shell structure of the nuclei involved. The analysis is generalized to all closed shells up to 48 Ca. It is predicted that no other nuclear state near closed shells, can decay by a pure simultaneous emission of two protons. The same analysis applied to the case of the simultaneous emission of two neutrons yielded the prediction of two sets of states in 14 C and 18 0 with such property. (Author)

  17. NOx cycle and tropospheric ozone isotope anomaly: an experimental investigation

    Science.gov (United States)

    Michalski, G.; Bhattacharya, S. K.; Girsch, G.

    2013-04-01

    The oxygen isotope composition of nitrogen oxides (NOx) in the atmosphere may be a useful tool for understanding the oxidation of NOx into nitric acid/nitrate in the atmosphere. A set of experiments were conducted to examine changes in isotopic composition of NOx due to O3-NOx photochemical cycling. At low NO2/O2 mixing ratios, NO2 becomes progressively and nearly equally enriched in 17O and 18O over time until it reaches a steady state with Δ17O values of 40.6 ± 1.9‰ and δ18O values of 84.2 ± 4‰, relative to the isotopic composition of the O2 gas. As the mixing ratio increases, isotopic exchange between O atoms and O2 and NOx suppresses the isotopic enrichments. A kinetic model simulating the observed data shows that the isotope effects during ozone formation play a more dominant role compared to kinetic isotope effects during NO oxidation or exchange of NO2. The model results are consistent with the data when the NO + O3 reaction occurs mainly via the transfer of the terminal atom of O3. The model predicts that under tropospheric concentrations of the three reactants, the timescale of NOx isotopic equilibrium ranges from hours (ppbv mixing ratios) to days/weeks (pptv) and yields steady state Δ17O and δ18O values of 46‰ and 115‰ respectively with respect to Vienna Standard Mean Ocean Water. Interpretation of tropospheric nitrate isotope data can now be done with the derived rate coefficients of the major isotopologue reactions at various pressures.

  18. Nox family NADPH oxidases in mechano-transduction: mechanisms and consequences.

    Science.gov (United States)

    Brandes, Ralf P; Weissmann, Norbert; Schröder, Katrin

    2014-02-20

    The majority of cells in a multi-cellular organism are continuously exposed to ever-changing physical forces. Mechano-transduction links these events to appropriate reactions of the cells involving stimulation of signaling cascades, reorganization of the cytoskeleton and alteration of gene expression. Mechano-transduction alters the cellular redox balance and the formation of reactive oxygen species (ROS). Nicotine amide adenine dinucleotide reduced form (NADPH) oxidases of the Nox family are prominent ROS generators and thus, contribute to this stress-induced ROS formation. Different types and patterns of mechano-stress lead to Nox-dependent ROS formation and Nox-mediated ROS formation contributes to cellular responses and adaptation to physical forces. Thereby, Nox enzymes can mediate vascular protection during physiological mechano-stress. Despite this, over-activation and induction of Nox enzymes and a subsequent substantial increase in ROS formation also promotes oxidative stress in pathological situations like disturbed blood flow or extensive stretch. Individual protein targets of Nox-mediated redox-signaling will be identified to better understand the specificity of Nox-dependent ROS signaling in mechano-transduction. Nox-inhibitors will be tested to reduce cellular activation in response to mechano-stimuli.

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

    International Nuclear Information System (INIS)

    Mahmood, A.; Javed, M.T.; Irfan, N.; Hamid, A. and K.; Waheed, K.

    2009-01-01

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

  20. COST-EFFECTIVE CONTROL OF NOx WITH INTEGRATED ULTRA LOW-NOx BURNERS AND SNCR

    Energy Technology Data Exchange (ETDEWEB)

    Hamid Farzan; Jennifer Sivy; Alan Sayre; John Boyle

    2003-07-01

    Under sponsorship of the Department of Energy's National Energy Technology Laboratory (NETL), McDermott Technology, Inc. (MTI), the Babcock & Wilcox Company (B&W), and Fuel Tech teamed together to investigate an integrated solution for NOx control. The system was comprised of B&W's DRB-4Z{trademark} low-NO{sub x} pulverized coal (PC) burner technology and Fuel Tech's NO{sub x}OUT{reg_sign}, a urea-based selective non-catalytic reduction (SNCR) technology. The technology's emission target is achieving 0.15 lb NO{sub x}/10{sup 6} Btu for full-scale boilers. Development of the low-NOx burner technology has been a focus in B&W's combustion program. The DRB-4Z{trademark} burner (see Figure 1.1) is B&W's newest low-NO{sub x} burner capable of achieving very low NO{sub x}. The burner is designed to reduce NO{sub x} by diverting air away from the core of the flame, which reduces local stoichiometry during coal devolatilization and, thereby, reduces initial NO{sub x} formation. Figure 1.2 shows the historical NO{sub x} emission levels from different B&W burners. Figure 1.2 shows that based on three large-scale commercial installations of the DRB-4Z{trademark} burners in combination with OFA ports, using Western subbituminous coal, the NO{sub x} emissions ranged from 0.16 to 0.18 lb/10{sup 6} Btu. It appears that with continuing research and development the Ozone Transport Rule (OTR) emission level of 0.15 lb NO{sub x}/10{sup 6} Btu is within the reach of combustion modification techniques for boilers using western U.S. subbituminous coals. Although NO{sub x} emissions from the DRB-4Z{trademark} burner are nearing OTR emission level with subbituminous coals, the utility boiler owners that use bituminous coals can still benefit from the addition of an SNCR and/or SCR system in order to comply with the stringent NO{sub x} emission levels facing them.

  1. CO2 emissions from developing countries: Better understanding the role of energy in the long term

    International Nuclear Information System (INIS)

    Sathaye, J.; Goldman, N.

    1991-07-01

    Recent years have witnessed a growing recognition of the link between emissions of carbon dioxide (CO 2 ) and changes in the global climate. of all anthropogenic activities, energy production and use generate the single largest portion of these greenhouse gases. Although developing countries currently account for a small share of global carbon emissions, their contribution is increasing rapidly. Due to the rapid expansion of energy demand in these nations, the developing world's share in global modern energy use rose from 16 to 27 percent between 1970 and 1990. If the growth rates observed over the past 20 years persist, energy demand in developing nations will surpass that in the countries of the Organization for Economic Cooperation and Development (OECD) early in the 21st century. The study seeks to examine the forces that galvanize the growth of energy use and carbon emissions, to assess the likely future levels of energy and CO 2 in selected developing nations and to identify opportunities for restraining this growth. The purpose of this report is to provide the quantitative information needed to develop effective policy options, not to identify the options themselves. A combined study was carried out for the countries of the Gulf Cooperation Council (Bahrain, Kuwait, Oman, Qatar, Saudi Arabia and the United Arab Emirates)

  2. Understanding the side effects of emission trading: implications for waste management.

    Science.gov (United States)

    Braschel, Nina; Posch, Alfred; Pierer, Magdalena

    2014-01-01

    The trading of emission allowances is an important market instrument in climate policy. However, the inclusion of certain branches of industry in the trading system not only provides incentives for emission reduction, it also entails unwanted side effects. Thus, the objective of the present study is to identify such side effects-positive and negative-by examining the potential impact of waste management inclusion in the European Union Emissions Trading Scheme (EU ETS). Desk research was supplemented with qualitative and quantitative empirical analysis (based on expert interviews and a questionnaire) in order to analyse the related perceptions and expectations of actors and stakeholders. The impact of waste management inclusion in the EU ETS is analysed in terms of the following three areas: (i) costs and cost pass-through, (ii), competitiveness and market position, and (iii) carbon leakage. Concerning expectations in the area of costs, both the interviewed experts and the practitioners surveyed thought that costs were likely to increase or that they could be passed on to customers. However, experts and practitioners differed with respect to the possibility of carbon leakage. Clearly, increased knowledge of the possible impact arising from inclusion of the waste sector in the EU ETS would enable managers to become more proactive and to manage waste streams and treatment options more economically.

  3. CO2 emissions from developing countries: Better understanding the role of energy in the long term

    International Nuclear Information System (INIS)

    Sathaye, J.; Goldman, N.

    1991-07-01

    Recent years have witnessed a growing recognition of the link between emissions of carbon dioxide (CO 2 ) and changes in the global climate. Of all anthropogenic activities, energy production and use generate the single largest portion of these greenhouse gases. Although developing countries currently account for a small share of global carbon emissions, their contribution is increasing rapidly. Due to the rapid expansion of energy demand in these nations, the developing world's share in global modern energy use rose from 16 to 27 percent between 1970 and 1990. If the growth rates observed over the past 20 years persist, energy demand in developing nations will surpass that in the countries of the Organization for Economic Cooperation and Development (OECD) early in the 21st century. The study seeks to examine the forces that galvanize the growth of energy use and carbon emissions, to assess the likely future levels of energy and Co 2 in selected developing nations and to identify opportunities for restraining this growth. The purpose of this report is to provide the quantitative information needed to develop effective policy options, not to identify the options themselves. These individual studies were conducted for China, India, Indonesia and South Korea in Asia

  4. CO2 emissions from developing countries: Better understanding the role of Energy in the long term

    International Nuclear Information System (INIS)

    Ketoff, A.; Sathaye, J.; Goldman, N.

    1991-07-01

    Recent years have witnessed a growing recognition of the link between emissions of carbon dioxide (CO 2 ) and changes in the global climate. Of all anthropogenic activities, energy production and use generate the single largest portion of these greenhouse gases. Although developing countries currently account for a small share of global carbon emissions, their contribution is increasing rapidly. Due to the rapid expansion of energy demand in these nations, the developing world's share in global modern energy use rose from 16 to 27 percent between 1970 and 1990. If the growth rates observed over the past 20 years persist energy demand in developing will surpass that in the countries of the Organization for Economic Cooperation and Development (OECD) early in the 21st century. The study seeks to examine the forces that galvanize the growth of energy use and carbon emissions, to assess the likely future levels of energy and CO 2 in selected developing nations and to identify opportunities for restraining this growth. The purpose of this report is to provide the quantitative information needed to develop effective policy options, not to identify the options themselves. These individual studies were conducted fro Argentina, Brazil, Mexico and Venezuela in Latin America

  5. On the Response of Ozone to Temperature at Low NOx Concentrations

    Science.gov (United States)

    Romer, P.; Duffey, K.; Wooldridge, P. J.; Brune, W. H.; Miller, D. O.; Feiner, P. A.; Zhang, L.; Goldstein, A. H.; Olson, K. F.; Misztal, P. K.; De Gouw, J. A.; Koss, A.; Edgerton, E. S.; Cohen, R. C.

    2016-12-01

    The relationship between ozone and temperature is an important tool for predicting how concentrations of ozone are likely to change as a function of climate and of precursor emissions. This relationship and the mechanisms that control it under low-NOx conditions remain poorly understood, especially in forested areas with high concentrations of biogenic volatile organic compounds. Here we combine detailed in-situ measurements from the 2013 Southern Oxidant and Aerosol Study (SOAS) in rural Alabama with long-term observations from the same location to assess the response of O3 to temperature at low NOx and to evaluate the chemical mechanisms that contribute to this response. We find that the response of local ozone production to temperature is controlled by temperature dependent changes in NOx chemistry. We analyze how the mechanisms that control this response vary with the concentration of NOx and compare the observed relationship between ozone concentration and temperature to the calculated changes in local ozone production.

  6. 40 CFR 97.82 - NOX authorized account representative.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false NOX authorized account representative... PROGRAMS (CONTINUED) FEDERAL NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS Individual Unit Opt-ins. § 97.82 NOX authorized account representative. A unit for which an application for a NOX...

  7. 40 CFR 97.50 - NOX Allowance Tracking System accounts.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false NOX Allowance Tracking System accounts... PROGRAMS (CONTINUED) FEDERAL NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS NOX Allowance Tracking System § 97.50 NOX Allowance Tracking System accounts. (a) Nature and function of compliance...

  8. 40 CFR 96.50 - NOX Allowance Tracking System accounts.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false NOX Allowance Tracking System accounts... PROGRAMS (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS FOR STATE IMPLEMENTATION PLANS NOX Allowance Tracking System § 96.50 NOX Allowance Tracking System accounts. (a) Nature and...

  9. Formaldehyde Production From Isoprene Oxidation Across NOx Regimes

    Science.gov (United States)

    Wolfe, G. M.; Kaiser, J.; Hanisco, T. F.; Keutsch, F. N.; de Gouw, J. A.; Gilman, J. B.; Graus, M.; Hatch, C. D.; Holloway, J.; Horowitz, L. W.; hide

    2016-01-01

    The chemical link between isoprene and formaldehyde (HCHO) is a strong, non-linear function of NOx (= NO + NO2). This relationship is a linchpin for top-down isoprene emission inventory verification from orbital HCHO column observations. It is also a benchmark for overall photochemical mechanism performance with regard to VOC oxidation. Using a comprehensive suite of airborne in situ observations over the southeast US, we quantify HCHO production across the urban-rural spectrum. Analysis of isoprene and its major first-generation oxidation products allows us to define both a prompt yield of HCHO (molecules of HCHO produced per molecule of freshly emitted isoprene) and the background HCHO mixing ratio (from oxidation of longer-lived hydrocarbons). Over the range of observed NOx values (roughly 0.1 - 2 ppbv), the prompt yield increases by a factor of 3 (from 0.3 to 0.9 ppbv ppbv(exp. -10), while background HCHO increases by a factor of 2 (from 1.6 to 3.3 ppbv). We apply the same method to evaluate the performance of both a global chemical transport model (AM3) and a measurement-constrained 0-D steady-state box model. Both models reproduce the NOx dependence of the prompt HCHO yield, illustrating that models with updated isoprene oxidation mechanisms can adequately capture the link between HCHO and recent isoprene emissions. On the other hand, both models underestimate background HCHO mixing ratios, suggesting missing HCHO precursors, inadequate representation of later-generation isoprene degradation and/or underestimated hydroxyl radical concentrations. Detailed process rates from the box model simulation demonstrate a 3-fold increase in HCHO production across the range of observed NOx values, driven by a 100% increase in OH and a 40% increase in branching of organic peroxy radical reactions to produce HCHO.

  10. Urban GHG emissions and resource flows: Methods for understanding the complex functioning of cities

    International Nuclear Information System (INIS)

    Yetano Roche, María

    2015-01-01

    This paper sums up the recent developments in concepts and methods being used to measure the impacts of cities on environmental sustainability. It differentiates between a dominant trend in research literature that concentrates on the accounting and allocation of greenhouse gas (GHG) emissions and energy use to cities, and a re-emergence of studies focusing on the direct and indirect urban material and resource flows. The availability of reliable data and standard protocols is greater in the GHG accounting field and continues to grow rapidly

  11. Towards a better understanding of hard photon emission in intermediate energy heavy ion collisions

    Energy Technology Data Exchange (ETDEWEB)

    Alba, R.; Maiolino, C.; Agodi, C.; Del Zoppo, A.; Coniglione, R.; Milazzo, P.M.; Sapienza, P.; Bellia, G.; Bruno, M.; Colonna, M.; Colonna, N.; D' Agostino, M.; Fiandri, M.L.; Finocchiaro, P.; Gramegna, F.; Iori, I.; Loukachine, K.; Margagliotti, G.V.; Mastinu, P.F.; Migneco, E.; Moroni, A.; Piattelli, P.; Rui, R.; Santonocito, D.; Tonetto, F.; Vannini, G

    1999-07-26

    High energy photon spectra have been measured in several {sup 58}Ni induced reactions at 30A MeV incident energy. A two source analysis of the data has been performed using a two exponential parameterization of the associated gamma spectra. The relative intensity of the two components has been deduced as a function of the total mass of the interacting system and of the impact parameter. To attempt a characterization of the emission sources, correlations between photons and IMF's have been measured for the first time.

  12. Towards a better understanding of hard photon emission in intermediate energy heavy ion collisions

    Science.gov (United States)

    Alba, R.; Maiolino, C.; Agodi, C.; Del Zoppo, A.; Coniglione, R.; Milazzo, P. M.; Sapienza, P.; Bellia, G.; Bruno, M.; Colonna, M.; Colonna, N.; D'Agostino, M.; Fiandri, M. L.; Finocchiaro, P.; Gramegna, F.; Iori, I.; Loukachine, K.; Margagliotti, G. V.; Mastinu, P. F.; Migneco, E.; Moroni, A.; Piattelli, P.; Rui, R.; Santonocito, D.; Tonetto, F.; Vannini, G.

    High energy photon spectra have been measured in several 58Ni induced reactions at 30A MeV incident energy. A two source analysis of the data has been performed using a two exponential parameterization of the associated gamma spectra. The relative intensity of the two components has been deduced as a function of the total mass of the interacting system and of the impact parameter. To attempt a characterization of the emission sources, correlations between photons and IMF's have been measured for the first time.

  13. Towards a better understanding of hard photon emission in intermediate energy heavy ion collisions

    International Nuclear Information System (INIS)

    Alba, R.; Maiolino, C.; Agodi, C.; Del Zoppo, A.; Coniglione, R.; Milazzo, P.M.; Sapienza, P.; Bellia, G.; Bruno, M.; Colonna, M.; Colonna, N.; D'Agostino, M.; Fiandri, M.L.; Finocchiaro, P.; Gramegna, F.; Iori, I.; Loukachine, K.; Margagliotti, G.V.; Mastinu, P.F.; Migneco, E.; Moroni, A.; Piattelli, P.; Rui, R.; Santonocito, D.; Tonetto, F.; Vannini, G.

    1999-01-01

    High energy photon spectra have been measured in several 58 Ni induced reactions at 30A MeV incident energy. A two source analysis of the data has been performed using a two exponential parameterization of the associated gamma spectra. The relative intensity of the two components has been deduced as a function of the total mass of the interacting system and of the impact parameter. To attempt a characterization of the emission sources, correlations between photons and IMF's have been measured for the first time

  14. Regional Marginal Abatement Cost Curves for NOx

    Data.gov (United States)

    U.S. Environmental Protection Agency — Data underlying the figures included in the manuscript "Marginal abatement cost curve for NOx incorporating controls, renewable electricity, energy efficiency and...

  15. Nox-4 and progressive kidney disease.

    Science.gov (United States)

    Thallas-Bonke, Vicki; Jandeleit-Dahm, Karin A M; Cooper, Mark E

    2015-01-01

    Nox-4 is a member of the NADPH oxidase (Nox) family of enzymes implicated in reactive oxygen species generation. Nox-4 is distributed in many tissues; however, its physiological functions remain poorly understood. In contrast to other Nox isoforms, it is unique in that it produces large amounts of hydrogen peroxide constitutively and does not require other cytosolic oxidase components for its activation. This review highlights the recent developments in Nox-4 research and progressive kidney disease as well as the potential of new Nox-4 inhibitors to reduce renal damage. Recently, Nox-4 was shown to be implicated in kidney diseases such as diabetic nephropathy. Nox-4 has been identified as playing a role in damage to the kidney induced by hyperglycaemia and other major pathways of renal damage, including advanced glycation end-products, the renin-angiotensin system, TGF-β and protein kinase C. The role of Nox-4 as a target for renoprotection remains controversial, although recent positive preclinical data have stimulated increased interest in inhibiting the enzyme in clinical trials of renal disease.

  16. DEVELOPMENT AND DEMONSTRATION OF NOVEL LOW-NOx BURNERS IN THE STEEL INDUSTRY

    Energy Technology Data Exchange (ETDEWEB)

    Cygan, David

    2006-12-28

    Gas Technology Institute (GTI), together with Hamworthy Peabody Combustion Incorporated (formerly Peabody Engineering Corporation), the University of Utah, and Far West Electrochemical have developed and demonstrated an innovative combustion system suitable for natural gas and coke-oven gas firing within the steel industry. The combustion system is a simple, low-cost, energy-efficient burner that can reduce NOx by more than 75%. The U.S. steel industry needs to address NOx control at its steelmaking facilities. A significant part of NOx emissions comes from gas-fired boilers. In steel plants, byproduct gases – blast furnace gas (BFG) and coke-oven gas (COG) – are widely used together with natural gas to fire furnaces and boilers. In steel plants, natural gas can be fired together with BFG and COG, but, typically, the addition of natural gas raises NOx emissions, which can already be high because of residual fuel-bound nitrogen in COG. The Project Team has applied its expertise in low-NOx burners to lower NOx levels for these applications by combining advanced burner geometry and combustion staging with control strategies tailored to mixtures of natural gas and byproduct fuel gases. These methods reduce all varieties of NOx – thermal NOx produced by high flame temperatures, prompt NOx produced by complex chain reactions involving radical hydrocarbon species and NOx from fuel-bound nitrogen compounds such as ammonia found in COG. The Project Team has expanded GTI’s highly successful low-NOx forced internal recirculation (FIR) burner, previously developed for natural gas-fired boilers, into facilities that utilize BFG and COG. For natural gas firing, these burners have been shown to reduce NOx emissions from typical uncontrolled levels of 80-100 vppm to single-digit levels (9 vppm). This is done without the energy efficiency penalties incurred by alternative NOx control methods, such as external flue gas recirculation (FGR), water injection, and selective non

  17. Understanding gold-thiolate cluster emission from self-assembled monolayers upon kiloelectronvolt ion bombardment.

    Science.gov (United States)

    Arezki, B; Delcorte, A; Garrison, B J; Bertrand, P

    2006-04-06

    This article focuses on the emission of organometallic clusters upon kiloelectronvolt ion bombardment of self-assembled monolayers. It is particularly relevant for the elucidation of the physical processes underlying secondary ion mass spectrometry (SIMS). The experimental system, an overlayer of octanethiols on gold, was modeled by classical molecular dynamics, using a hydrocarbon potential involving bonding and nonbonding interactions (AIREBO). To validate the model, the calculated mass and energy distributions of sputtered atoms and molecules were compared to experimental data. Our key finding concerns the emission mechanism of large clusters of the form MxAuy up to M6Au5 (where M is the thiolate molecule), which were not observed under sub-kiloelectronvolt projectile bombardment. Statistically, they are predominantly formed in high-yield events, where many atoms, fragments, and (supra)molecular species are desorbed from the surface. From the microscopic viewpoint, these high-yield events mostly stem from the confinement of the projectile and recoil atom energies in a finite microvolume of the sample surface. As a result of the high local energy density, molecular aggregates desorb from an overheated liquidlike region surrounding the impact point of the projectile.

  18. 40 CFR 97.52 - NOX Allowance Tracking System responsibilities of NOX authorized account representative.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false NOX Allowance Tracking System responsibilities of NOX authorized account representative. 97.52 Section 97.52 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) FEDERAL NOX BUDGET TRADING PROGRAM AND CAIR...

  19. a Comprehensive Study of the Milan Urban Plume: Gas Phase, Aerosols and ROG/NOx-SENSITIVITY

    Science.gov (United States)

    Dommen, J.; Bärtsch-Ritter, N.; Andreani-Aksoyoglu, S.; Keller, J.; Prevot, A. S. H.

    2003-04-01

    Three-dimensional photochemical models were used to investigate the temporal and spatial dynamics of the photooxidant and aerosol production in the highly polluted Milan area (Italy). A simulation of the 13 May, 1998 event is presented, when peak ozone levels of 190 ppb were measured in the urban plume. The model base case is able to reproduce the ozone concentration in the center of the plume but more peroxide is formed than in the adjacent areas in contradiction to observation. This can be interpreted as a tendency of the model towards a stronger NOx sensitivity compared to observation. The emission inventory was modified based on experimental evidence. Ozone levels did not differ much between the base case simulation and those with a modified emission inventory, while peroxide formation and NOx concentrations in the urban plume did. That lead to a better agreement with measurements. Based on this measurement-model comparison we studied the ROG/NOx sensitivity of the ozone production in this area. We also investigated the effects of various meteorological conditions and the resolution of the emission inventory on the ozone mixing ratio and the ROG/NOx sensitivity. It was found, that the net ozone formation in northern Italy depends stronger on temperature than humidity, while the humidity is more important for the ROG/NOx sensitivity of the ozone production. NOx sensitive areas increase only if much coarser emission inventories were used. Higher wind speeds increased ROG sensitive areas. The influence of strong point emission source was also investigated. The study was then extended to the calculation of secondary aerosol species such as particulate nitrate, ammonium, sulfate, and SOC (secondary organic carbon) for the particle sizes below 2.5 µm. The comparison between model results and observations will be presented and discussed.

  20. Nox1 oxidase suppresses influenza a virus-induced lung inflammation and oxidative stress.

    Directory of Open Access Journals (Sweden)

    Stavros Selemidis

    Full Text Available Influenza A virus infection is an ongoing clinical problem and thus, there is an urgent need to understand the mechanisms that regulate the lung inflammation in order to unravel novel generic pharmacological strategies. Evidence indicates that the Nox2-containing NADPH oxidase enzyme promotes influenza A virus-induced lung oxidative stress, inflammation and dysfunction via ROS generation. In addition, lung epithelial and endothelial cells express the Nox1 isoform of NADPH oxidase, placing this enzyme at key sites to regulate influenza A virus-induced lung inflammation. The aim of this study was to investigate whether Nox1 oxidase regulates the inflammatory response and the oxidative stress to influenza infection in vivo in mice. Male WT and Nox1-deficient (Nox1(-/y mice were infected with the moderately pathogenic HkX-31 (H3N2, 1×10(4 PFU influenza A virus for analysis of bodyweight, airways inflammation, oxidative stress, viral titre, lung histopathology, and cytokine/chemokine expression at 3 and 7 days post infection. HkX-31 virus infection of Nox1(-/y mice resulted in significantly greater: loss of bodyweight (Day 3; BALF neutrophilia, peri-bronchial, peri-vascular and alveolar inflammation; Nox2-dependent inflammatory cell ROS production and peri-bronchial, epithelial and endothelial oxidative stress. The expression of pro-inflammatory cytokines including CCL2, CCL3, CXCL2, IL-1β, IL-6, GM-CSF and TNF-α was higher in Nox1(-/y lungs compared to WT mice at Day 3, however, the expression of CCL2, CCL3, CXCL2, IFN-γ and the anti-inflammatory cytokine IL-10 were lower in lungs of Nox1(-/y mice vs. WT mice at Day 7. Lung viral titre, and airways infiltration of active CD8(+ and CD4(+ T lymphocytes, and of Tregs were similar between WT and Nox1(-/y mice. In conclusion, Nox1 oxidase suppresses influenza A virus induced lung inflammation and oxidative stress in mice particularly at the early phases of the infection. Nox1 and Nox2 oxidases appear

  1. Evaluation of Gas Reburning & Low NOx Burners on a Wall Fired Boiler Performance and Economics Report Gas Reburning-Low NOx Burner System Cherokee Station Unit 3 Public Service Company of Colorado

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    1998-07-01

    Under the U.S. Department of Energy's Clean Coal Technology Program (Round 3), a project was completed to demonstrate control of boiler NOX emissions and to a lesser degree, due to coal replacement, SO2 emissions. The project involved combining Gas Reburning with Low NOX Burners (GR-LNB) on a coal-fired electric utility boiler to determine if high levels of NOX reduction (70%) could be achieved. Sponsors of the project included the U.S. Department of Energy, the Gas Research Institute, Public Service Company of Colorado, Colorado Interstate Gas, Electric Power Research Institute, and the Energy and Environmental Research Corporation. The GR-LNB demonstration was performed on Public Service Company of Colorado's (PSCO) Cherokee Unit #3, located in Denver, Colorado. This unit is a 172 MW~ wall-fired boiler that uses Colorado Bituminous, low-sulfur coal. It had a baseline NOX emission level of 0.73 lb/106 Btu using conventional burners. Low NOX burners are designed to yield lower NOX emissions than conventional burners. However, the NOX control achieved with this technique is limited to 30-50%. Also, with LNBs, CO emissions can increase to above acceptable standards. Gas Reburning (GR) is designed to reduce NOX in the flue gas by staged fuel combustion. This technology involves the introduction of natural gas into the hot furnace flue gas stream. When combined, GR and LNBs minimize NOX emissions and maintain acceptable levels of CO emissions. A comprehensive test program was completed, operating over a wide range of boiler conditions. Over 4,000 hours of operation were achieved, providing substantial data. Measurements were taken to quantify reductions in NOX emissions, the impact on boiler equipment and operability and factors influencing costs. The GR-LNB technology achieved good NOX emission reductions and the goals of the project were achieved. Although the performance of the low NOX burners (supplied by others) was less than expected, a NOX reduction of

  2. Understanding the primary emissions and secondary formation of gaseous organic acids in the oil sands region of Alberta, Canada

    Directory of Open Access Journals (Sweden)

    J. Liggio

    2017-07-01

    little contributions from biogenic VOC precursors. The model results, together with an examination of the carbon mass balance between the organic acids formed and the primary VOCs emitted from oil sands operations, suggest the existence of significant missing secondary sources and precursor emissions related to oil sands and/or an incomplete mechanistic and quantitative understanding of how they are processed in the atmosphere.

  3. Understanding the primary emissions and secondary formation of gaseous organic acids in the oil sands region of Alberta, Canada

    Science.gov (United States)

    Liggio, John; Moussa, Samar G.; Wentzell, Jeremy; Darlington, Andrea; Liu, Peter; Leithead, Amy; Hayden, Katherine; O'Brien, Jason; Mittermeier, Richard L.; Staebler, Ralf; Wolde, Mengistu; Li, Shao-Meng

    2017-07-01

    results, together with an examination of the carbon mass balance between the organic acids formed and the primary VOCs emitted from oil sands operations, suggest the existence of significant missing secondary sources and precursor emissions related to oil sands and/or an incomplete mechanistic and quantitative understanding of how they are processed in the atmosphere.

  4. Biological NOx removal by denitrification process in a jet-loop bioreactor: system performance and model development.

    Science.gov (United States)

    Durmazpinar, Serdar; Ilhan, Nalan; Demir, Gonca; Insel, Güçlü; Dizge, Nadir; Ergenekon, Pinar; Erhan, Elif; Keskinler, Bülent

    2014-01-01

    Nitrogen monoxide (NO) and nitrogen dioxide referred as NOx are one of the most important air pollutants in the atmosphere. Biological NOx removal technologies have been developing to reach a cost-effective control method for upcoming stringent NOx emission standards. The BioDeNOx system was seen as a promising biological NOx control technology which is composed of two reactors, one for absorbing of NO in an aqueous Fe(II)EDTA2- solution and the other for subsequent reduction to N2 gas in a biological reactor by the denitrification process. In this study, instead of two discrete reactors, only one jet-loop bioreactor (JLBR) was utilized as both absorption and denitrification unit and no chelate-forming chemicals were added. In other words, the advantage of better mass transfer conditions of jet bioreactor was used instead of Fe(II)EDTA2-. The process was named as Jet-BioDeNOx. The JLBR was operated for the removal of NOx from air streams containing 500-3000 ppm NOx and the results showed that the removal efficiency was between 81% and 94%. The air to liquid flow ratio (Q(G)/Q(RAS)) varied in the range of 0.07-0.12. Mathematical modelling of the system demonstrated that the removal efficiency strongly depends on this ratio. The high mass transfer conditions prevailed in the reactor provided a competitive advantage on removing NO gas without any requirement of chelating chemicals.

  5. Understanding the impact of recent advances in isoprene photooxidation on simulations of regional air quality

    Directory of Open Access Journals (Sweden)

    Y. Xie

    2013-08-01

    Full Text Available The CMAQ (Community Multiscale Air Quality us model in combination with observations for INTEX-NA/ICARTT (Intercontinental Chemical Transport Experiment–North America/International Consortium for Atmospheric Research on Transport and Transformation 2004 are used to evaluate recent advances in isoprene oxidation chemistry and provide constraints on isoprene nitrate yields, isoprene nitrate lifetimes, and NOx recycling rates. We incorporate recent advances in isoprene oxidation chemistry into the SAPRC-07 chemical mechanism within the US EPA (United States Environmental Protection Agency CMAQ model. The results show improved model performance for a range of species compared against aircraft observations from the INTEX-NA/ICARTT 2004 field campaign. We further investigate the key processes in isoprene nitrate chemistry and evaluate the impact of uncertainties in the isoprene nitrate yield, NOx (NOx = NO + NO2 recycling efficiency, dry deposition velocity, and RO2 + HO2 reaction rates. We focus our examination on the southeastern United States, which is impacted by both abundant isoprene emissions and high levels of anthropogenic pollutants. We find that NOx concentrations increase by 4–9% as a result of reduced removal by isoprene nitrate chemistry. O3 increases by 2 ppbv as a result of changes in NOx. OH concentrations increase by 30%, which can be primarily attributed to greater HOx production. We find that the model can capture observed total alkyl and multifunctional nitrates (∑ANs and their relationship with O3 by assuming either an isoprene nitrate yield of 6% and daytime lifetime of 6 hours or a yield of 12% and lifetime of 4 h. Uncertainties in the isoprene nitrates can impact ozone production by 10% and OH concentrations by 6%. The uncertainties in NOx recycling efficiency appear to have larger effects than uncertainties in isoprene nitrate yield and dry deposition velocity. Further progress depends on improved understanding of

  6. From a Better Understanding of GRB Prompt Emission to a New Type of Standard Candles?

    Science.gov (United States)

    Guiriec, Sylvain

    2016-07-01

    Recent results revealed the simultaneous existence of multiple components in the prompt emission of gamma-ray bursts (GRBs) leading to a unified spectro-temporal model for the broadband spectrum from the optical regime up to higher gamma rays. Unexpectedly, we discovered a relation intrinsic to one specific component of this model: its luminosity is strongly and tightly correlated to its spectral break energy. This new luminosity-hardness relation has the same index for all GRBs when fitted to a power law. In addition, this relation seems to have the same normalization for all GRBs; therefore, this is a promising and physically motivated tool that may establish GRBs as cosmological standard candles. During this presentation, I will introduce this new relation, which might eventually be used to (i) estimate GRB distances, (ii) to support searches for gravitational waves and cosmic high-energy neutrinos, and (iii) constrain the cosmological parameters. I will give a few examples of GRB redshift estimates using this relation and I will show why this new result cannot solely be explain by instrumental selection effects and/or measurement/analysis biases.

  7. Understanding the differing governance of EU emissions trading and renewable: feedback mechanisms and policy entrepreneurs

    Energy Technology Data Exchange (ETDEWEB)

    Boasson, Elin Lerum; Wettestad, Joergen

    2010-04-15

    This paper presents a comparative study of two central EU climate policies: the revised Emissions Trading System (ETS), and the revised Renewable Energy Directive (RES). Both were originally developed in the early 2000s and revised policies were adopted in December 2008. While the ETS from 2013 on will have a quite centralized and market-streamlined design, the revised RES stands forward as a more decentralized and technology-focused policy. Differing institutional feed-back mechanisms and related roles of policy entrepreneurs can shed considerable light on these policy differences. Due to member states' cautiousness and contrary to the preferences of the Commission, the initial ETS was designed as a rather decentralized and 'politicized' market system, creating a malfunctioning institutional dynamic. In the revision process, the Commission skillfully highlighted this ineffective dynamic to win support for a much more centralized and market-streamlined approach. In the case of RES, national technology-specific support schemes and the strong links between the renewable industry and member states promoted the converse outcome: decentralization and technology development. Members of the European Parliament utilized these mechanisms through policy networking, while the Commission successfully used developments within the global climate regime to induce some degree of centralization. (Author)

  8. Understanding and mitigating the challenge of bioaerosol emissions from urban community composting

    Science.gov (United States)

    Pankhurst, L. J.; Akeel, U.; Hewson, C.; Maduka, I.; Pham, P.; Saragossi, J.; Taylor, J.; Lai, K. M.

    2011-01-01

    Within the UK, local and regional government drives to reduce the quantity of waste being sent to landfill have led to an increase in small-scale composting schemes, instigated by local councils and not-for-profit organisations. The composting process relies upon the proliferation of microorganisms, leading to their emission into the ambient environment. In this investigative study, total bacteria and Aspergillus fumigatus emitted from a small-scale composting facility in central London were measured in different spatial and temporal dimensions. Bioaerosols did not disperse in concentrations significantly higher than those measured at 'background' locations, where maximum geometric mean was 55 × 10 2 Colony Forming Units (CFU) per m -3. Concentrations on-site and at the nearest potential receptor were comparable to those found at commercial facilities, reaching 25 × 10 4 and 29 × 10 3 CFU m -3 for total bacteria and A. fumigatus respectively. The room housing the facility was contaminated by moulds; likely to result from high relative humidity of the air (consistently above 80% during this study), building material, and the generation of organic dust. The complex diurnal meteorological variations of urban environments are likely to influence bioaerosol dispersal, and consequent exposure risk for sensitive receptors. Site planning tools including Geographical Information Systems (GIS) mapping with buffer zones around schools and hospitals, and use of computerised models for the design of rooms housing urban composting facilities are proposed as methods for reducing the risk of occupational and off-site receptor exposure.

  9. Marginal abatement cost curves for NOx that account for ...

    Science.gov (United States)

    A marginal abatement cost curve (MACC) traces out the relationship between the quantity of pollution abated and the marginal cost of abating each additional unit. In the context of air quality management, MACCs typically are developed by sorting end-of-pipe controls by their respective cost effectiveness. Alternative measures, such as renewable electricity, energy efficiency, and fuel switching (RE/EE/FS), are not considered as it is difficult to quantify their abatement potential. In this paper, we demonstrate the use of an energy system model to develop a MACC for nitrogen oxides (NOx) that incorporates both end-of-pipe controls and these alternative measures. We decompose the MACC by sector, and evaluate the cost-effectiveness of RE/EE/FS relative to end-of-pipe controls. RE/EE/FS are shown to produce considerable emission reductions after end-of-pipe controls have been exhausted. Furthermore, some RE/EE/FS are shown to be cost-competitive with end-of-pipe controls. Demonstrate how the MARKAL energy system model can be used to evaluate the potential role of renewable electricity, energy efficiency and fuel switching (RE/EE/FS) in achieving NOx reductions. For this particular analysis, we show that RE/EE/FSs are able to increase the quantity of NOx reductions available for a particular marginal cost (ranging from $5k per ton to $40k per ton) by approximately 50%.

  10. Flexible NO(x) abatement from power plants in the eastern United States.

    Science.gov (United States)

    Sun, Lin; Webster, Mort; McGaughey, Gary; McDonald-Buller, Elena C; Thompson, Tammy; Prinn, Ronald; Ellerman, A Denny; Allen, David T

    2012-05-15

    Emission controls that provide incentives for maximizing reductions in emissions of ozone precursors on days when ozone concentrations are highest have the potential to be cost-effective ozone management strategies. Conventional prescriptive emissions controls or cap-and-trade programs consider all emissions similarly regardless of when they occur, despite the fact that contributions to ozone formation may vary. In contrast, a time-differentiated approach targets emissions reductions on forecasted high ozone days without imposition of additional costs on lower ozone days. This work examines simulations of such dynamic air quality management strategies for NO(x) emissions from electric generating units. Results from a model of day-specific NO(x) pricing applied to the Pennsylvania-New Jersey-Maryland (PJM) portion of the northeastern U.S. electrical grid demonstrate (i) that sufficient flexibility in electricity generation is available to allow power production to be switched from high to low NO(x) emitting facilities, (ii) that the emission price required to induce EGUs to change their strategies for power generation are competitive with other control costs, (iii) that dispatching strategies, which can change the spatial and temporal distribution of emissions, lead to ozone concentration reductions comparable to other control technologies, and (iv) that air quality forecasting is sufficiently accurate to allow EGUs to adapt their power generation strategies.

  11. Sulfate-nitrate-ammonium aerosols over China: response to 2000–2015 emission changes of sulfur dioxide, nitrogen oxides, and ammonia

    Directory of Open Access Journals (Sweden)

    Y. Wang

    2013-03-01

    Full Text Available We use a chemical transport model to examine the change of sulfate-nitrate-ammonium (SNA aerosols over China due to anthropogenic emission changes of their precursors (SO2, NOx and NH3 from 2000 to 2015. From 2000 to 2006, annual mean SNA concentrations increased by about 60% over China as a result of the 60% and 80% increases in SO2 and NOx emissions. During this period, sulfate is the dominant component of SNA over South China (SC and Sichuan Basin (SCB, while nitrate and sulfate contribute equally over North China (NC. Based on emission reduction targets in the 12th (2011–2015 Five-Year Plan (FYP, China's total SO2 and NOx emissions are projected to change by −16% and +16% from 2006 to 2015, respectively. The amount of NH3 emissions in 2015 is uncertain, given the lack of sufficient information on the past and present levels of NH3 emissions in China. With no change in NH3 emissions, SNA mass concentrations in 2015 will decrease over SCB and SC compared to their 2006 levels, but increase over NC where the magnitude of nitrate increase exceeds that of sulfate reduction. This suggests that the SO2 emission reduction target set by the 12th FYP, although effective in reducing SNA over SC and SCB, will not be successful over NC, for which NOx emission control needs to be strengthened. If NH3 emissions are allowed to keep their recent growth rate and increase by +16% from 2006 to 2015, the benefit of SO2 reduction will be completely offset over all of China due to the significant increase of nitrate, demonstrating the critical role of NH3 in regulating nitrate. The effective strategy to control SNA and hence PM2.5 pollution over China should thus be based on improving understanding of current NH3 emissions and putting more emphasis on controlling NH3 emissions in the future.

  12. Measurement of NOx and CO Fluxes from a Tall Tower in Beijing.

    Science.gov (United States)

    Squires, F. A.; Drysdale, W. S.; Hamilton, J.; Lee, J. D.; Vaughan, A. R.; Wild, O.; Mullinger, N.; Nemitz, E.; Metzger, S.; Zhang, Q.

    2017-12-01

    China's air quality problems are well publicised; in 2010, 1.2 million premature deaths were attributed to outdoor air pollution in China. One of the major air quality issues is high concentrations of nitrogen oxides (NOx). China is the largest NOx emitter, contributing an estimated 18 % to global NOx emissions. Beijing itself is reported to have NO2 concentrations 42 % higher than the annual national standard. Given the high levels of pollution, increased focus has been placed on improving emissions estimates which are typically developed using a `bottom-up' approach where emissions are predicted from their sources. Emission inventories in China have large uncertainties and are rapidly changing with time in response to economic development, environmental regulation and new technologies. In fact, China is the largest contributor to the uncertainty in the source and the magnitude of air pollutants in air quality models. Recent studies have shown a discrepancy between NOx inventories and measured NOx emissions for UK cities, highlighting the limitations of bottom-up emissions inventories and the importance of accurate measurement data to improve the estimates. 5 Hz measurements of NOx and CO concentration were made as part of the Air Pollutants in Beijing (AIRPOLL-Beijing) project during two field campaigns in Nov-Dec 2016 and May-June 2017. Sampling took place from an inlet co-located with a sonic anemometer at 102 m on a meteorological tower in central Beijing. Analysis of the covariance between vertical wind speed and concentration enabled the calculation of emission flux, with an estimated footprint of between 2 - 5 km from the tower (which typically included some major ring roads and expressways). Fluxes were quantified using the continuous wavelet transformation (CWT) method, which enabled one minute resolved fluxes to be calculated. These data were compared to existing emissions estimates from the Multi-resolution Emission Inventory for China (MEIC). It is

  13. Direct plasma NOx reduction using single surface dielectric barrier discharge

    DEFF Research Database (Denmark)

    Kroushawi, Feisal; Stamate, Eugen

    2014-01-01

    NOx reduction using direct atmospheric barrier discharge in air-NO mixture at different voltages and flow rates is inversigated. Reduction rate of 80% is achieved at 3.18 W/cm2 power density and gas mixture of 20 slm air and 0.006 slm NO. The ozone for NO reduction is produced by a honeycomb...... structured DBD with a total surface of 12.56 cm2. The reduction process is investigated by FTIR spectroscopy, chemiluminsecence, mass spectrometry and optical emission spectroscopy....

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

    Directory of Open Access Journals (Sweden)

    Asif Muhammad

    2015-01-01

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

  15. 78 FR 54962 - Approval and Promulgation of Air Quality Implementation Plans; Connecticut; NOX

    Science.gov (United States)

    2013-09-09

    ... ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 52 [EPA-R01-OAR-2012-0198; A-1-FRL-9900-63-Region1] Approval and Promulgation of Air Quality Implementation Plans; Connecticut; NOX Emission Trading Orders as Single Source SIP Revisions AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY...

  16. Numerical modeling of nitrogen oxide emission and experimental verification

    Directory of Open Access Journals (Sweden)

    Szecowka Lech

    2003-12-01

    Full Text Available The results of nitrogen reduction in combustion process with application of primary method are presented in paper. The reduction of NOx emission, by the recirculation of combustion gasses, staging of fuel and of air was investigated, and than the reduction of NOx emission by simultaneous usage of the mentioned above primary method with pulsatory disturbances.The investigations contain numerical modeling of NOx reduction and experimental verification of obtained numerical calculation results.

  17. Advanced Petroleum-Based Fuels - Diesel Emissions Project (APBF-DEC): 2,000-Hour Performance of a NOx Adsorber Catalyst and Diesel Particle Filter System for a Medium-Duty, Pick-Up Diesel Engine Platform; Final Report

    Energy Technology Data Exchange (ETDEWEB)

    2007-03-01

    Presents the results of a 2,000-hour test of an emissions control system consisting of a nitrogen oxides adsorber catalyst in combination with a diesel particle filter, advanced fuels, and advanced engine controls in an SUV/pick-up truck vehicle platform.

  18. Chemical reactions in combustion of peat and biomass in two fluidized-bed boilers, CFB (25 MW) and BFB (25 MW) at Oestersund. The effect on SO2- and NOx-emissions by operating conditions and type of fuel

    International Nuclear Information System (INIS)

    Nordin, A.

    1991-03-01

    Most of the air pollutants are emitted from different combustion processes and much work is therefore needed to reduce these emissions. The processes are however extremely complex and to be able to study them, fundamental chemical and physical principles have to be taken into account. The aim of the present work has been to show the importance of equilibrium chemistry to improve the knowledge of specific combustion problems as well as the processes as a whole. This will also increase the possibilities to reduce the pollutants. The measured values from two combustion units (CFB and BFB, 25 MW) show good agreement with the corresponding calculated equilibrium values. The following are some of the more important results obtained: - By co-firing peat with biomass, the total SO 2 emissions can be reduced. The effects of variations in temperature and oxygen level on the SO 2 emissions are also reported; - The NO x emission levels agree well with the equilibrium levels, that is they increase with temperature and oxygen levels. Therefore, the amount of nitrogen in the fuel has shown to have insignificant effect in these experiments; - Initial levels of N 2 O are effectively reduced by high temperatures (> 950 deg Centigrade). (Orig.). ( 36 refs., 26 figs., 18 tabs.)

  19. Recombinant Nox4 cytosolic domain produced by a cell or cell-free base systems exhibits constitutive diaphorase activity

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Minh Vu Chuong, E-mail: mvchuong@yahoo.fr [GREPI AGIM FRE 3405 CNRS-UJF, Universite Joseph Fourier, Grenoble (France); Zhang, Leilei [GREPI AGIM FRE 3405 CNRS-UJF, Universite Joseph Fourier, Grenoble (France); Lhomme, Stanislas; Mouz, Nicolas [PX' Therapeutics, MINATEC/Batiment de Haute Technologie, Grenoble (France); Lenormand, Jean-Luc [HumProTher Laboratory, TheReX/TIMC-IMAG UMR 5525 CNRS UJF, Universite Joseph Fourier, UFR de Medecine, Domaine de la Merci, 38706 La Tronche (France); Lardy, Bernard; Morel, Francoise [GREPI AGIM FRE 3405 CNRS-UJF, Universite Joseph Fourier, Grenoble (France)

    2012-03-16

    Highlights: Black-Right-Pointing-Pointer A comparison of two bacterial cell and cell-free protein expression systems is presented. Black-Right-Pointing-Pointer Soluble and active truncated Nox4 proteins are produced. Black-Right-Pointing-Pointer Nox4 has a constitutive diaphorase activity which is independent of cytosolic factors. Black-Right-Pointing-Pointer Isoform Nox4B is unable to initiate the first electronic transfer step. Black-Right-Pointing-Pointer Findings contribute to the understanding of the mechanism of Nox4 oxidase activity. -- Abstract: The membrane protein NADPH (nicotinamide adenine dinucleotide phosphate) oxidase Nox4 constitutively generates reactive oxygen species differing from other NADPH oxidases activity, particularly in Nox2 which needs a stimulus to be active. Although the precise mechanism of production of reactive oxygen species by Nox2 is well characterized, the electronic transfer throughout Nox4 remains unclear. Our study aims to investigate the initial electronic transfer step (diaphorase activity) of the cytosolic tail of Nox4. For this purpose, we developed two different approaches to produce soluble and active truncated Nox4 proteins. We synthesized soluble recombinant proteins either by in vitro translation or by bacteria induction. While proteins obtained by bacteria induction demonstrate an activity of 4.4 {+-} 1.7 nmol/min/nmol when measured against iodonitro tetrazolium chloride and 20.5 {+-} 2.8 nmol/min/nmol with cytochrome c, the soluble proteins produced by cell-free expression system exhibit a diaphorase activity with a turn-over of 26 {+-} 2.6 nmol/min/nmol when measured against iodonitro tetrazolium chloride and 48 {+-} 20.2 nmol/min/nmol with cytochrome c. Furthermore, the activity of the soluble proteins is constitutive and does not need any stimulus. We also show that the cytosolic tail of the isoform Nox4B lacking the first NADPH binding site is unable to demonstrate any diaphorase activity pointing out the

  20. 40 CFR 96.82 - NOX authorized account representative.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false NOX authorized account representative... PROGRAMS (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS FOR STATE IMPLEMENTATION PLANS Individual Unit Opt-ins § 96.82 NOX authorized account representative. A unit for which an...

  1. Uncertainties in emission estimates of greenhouse gases and air pollutants in China and India and their impacts on regional air quality

    Science.gov (United States)

    Saikawa, E.; Trail, M.; Young, C. L.; Zhong, M.; Avramov, A.; Kim, H.; Wu, Q.; Janssens-Maenhout, G. G. A.; Kurokawa, J. I.; Klimont, Z.; Wagner, F.; Naik, V.; Horowitz, L. W.; Zhao, Y.; Nagpure, A.; Gurjar, B.; Zhang, Q.

    2017-12-01

    Greenhouse gas and air pollutant precursor emissions have been increasing rapidly in both China and India, resulting in local to regional scale effects on air quality. Modelers use emission inventories to represent the temporal and spatial distribution of impacts of air pollutant emissions on regional and global air quality. However, large uncertainties exist in emission inventories. Quantification of uncertainties in emission estimates is essential to better understand the linkages among emissions, air quality, climate, and health. We use Monte Carlo methods to assess the uncertainties of the existing carbon dioxide (CO2), carbon monoxide (CO), sulfur dioxide (SO2), nitrogen oxides (NOx), and particulate matter (PM) emission estimates for both China and India. We focus on the period between 2000 and 2008. In addition to national totals, we also analyze emissions from four source sectors, including industry, transport, power, and residential. We also assess differences in the existing emission estimates within each of the subnational regions. We find large disagreements among the existing inventories at disaggregated levels. We further assess the impact of these differences in emissions on air quality using a chemical transport model. More efforts are needed to constrain emissions, especially in the Indo-Gangetic Plains and in the East and Central regions of China, where large differences across emission inventories result in concomitant large differences in the simulated concentrations of PM and ozone. Our study also highlights the importance of constraining SO2, NOx, and NH3 emissions for secondary PM concentrations over China and India.

  2. 40 CFR 96.388 - CAIR NOX Ozone Season allowance allocations to CAIR NOX Ozone Season opt-in units.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false CAIR NOX Ozone Season allowance allocations to CAIR NOX Ozone Season opt-in units. 96.388 Section 96.388 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND...

  3. 40 CFR 96.12 - Changing the NOX authorized account representative and the alternate NOX authorized account...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Changing the NOX authorized account representative and the alternate NOX authorized account representative; changes in the owners and operators. 96... (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS FOR STATE IMPLEMENTATION PLANS...

  4. A numerical study on extinction and NOx formation in nonpremixed flames with syngas fuel

    KAUST Repository

    Chun, Kangwoo

    2011-11-01

    The flame structure, extinction, and NOx emission characteristics of syngas/air nonpremixed flames, have been investigated numerically. The extinction stretch rate increased with the increase in the hydrogen proportion in the syngas and with lower fuel dilution and higher initial temperature. It also increased with pressure, except for the case of highly diluted fuel at high pressure. The maximum temperature and the emission index of nitric oxides (EINOx) also increased in aforementioned conditions. The EINOx decreased with stretch rate in general, while the decreasing rate was found to be somewhat different between the cases of N2 and CO2 dilutions. The reaction paths of NOx formation were analyzed and represented as NO reaction path diagram. The increase in N radical resulted in larger NOx production at high initial temperature and pressure. As the pressure increases, EINOx increases slower due to the third-body recombination. The thermal NO mechanism is weakened for high dilution cases and non-thermal mechanisms prevail. The combustion conditions achieving higher extinction stretch rate can be lead to more NOx emission, therefore that the selection of optimum operation range is needed in syngas combustion. © 2011 The Korean Society of Mechanical Engineers and Springer-Verlag Berlin Heidelberg.

  5. Photochemical modeling in California with two chemical mechanisms: model intercomparison and response to emission reductions.

    Science.gov (United States)

    Cai, Chenxia; Kelly, James T; Avise, Jeremy C; Kaduwela, Ajith P; Stockwell, William R

    2011-05-01

    An updated version of the Statewide Air Pollution Research Center (SAPRC) chemical mechanism (SAPRC07C) was implemented into the Community Multiscale Air Quality (CMAQ) version 4.6. CMAQ simulations using SAPRC07C and the previously released version, SAPRC99, were performed and compared for an episode during July-August, 2000. Ozone (O3) predictions of the SAPRC07C simulation are generally lower than those of the SAPRC99 simulation in the key areas of central and southern California, especially in areas where modeled concentrations are greater than the federal 8-hr O3 standard of 75 parts per billion (ppb) and/or when the volatile organic compound (VOC)/nitrogen oxides (NOx) ratio is less than 13. The relative changes of ozone production efficiency (OPE) against the VOC/NOx ratio at 46 sites indicate that the OPE is reduced in SAPRC07C compared with SAPRC99 at most sites by as much as approximately 22%. The SAPRC99 and SAPRC07C mechanisms respond similarly to 20% reductions in anthropogenic VOC emissions. The response of the mechanisms to 20% NOx emissions reductions can be grouped into three cases. In case 1, in which both mechanisms show a decrease in daily maximum 8-hr O3 concentration with decreasing NOx emissions, the O3 decrease in SAPRC07C is smaller. In case 2, in which both mechanisms show an increase in O3 with decreasing NOx emissions, the O3 increase is larger in SAPRC07C. In case 3, SAPRC07C simulates an increase in O3 in response to reduced NOx emissions whereas SAPRC99 simulates a decrease in O3 for the same region. As a result, the areas where NOx controls would be disbeneficial are spatially expanded in SAPRC07C. Although the results presented here are valuable for understanding differences in predictions and model response for SAPRC99 and SAPRC07C, the study did not evaluate the impact of mechanism differences in the context of the U.S. Environmental Protection Agency's guidance for using numerical models in demonstrating air quality attainment

  6. NOx, Soot, and Fuel Consumption Predictions under Transient Operating Cycle for Common Rail High Power Density Diesel Engines

    Directory of Open Access Journals (Sweden)

    N. H. Walke

    2016-01-01

    Full Text Available Diesel engine is presently facing the challenge of controlling NOx and soot emissions on transient cycles, to meet stricter emission norms and to control emissions during field operations. Development of a simulation tool for NOx and soot emissions prediction on transient operating cycles has become the most important objective, which can significantly reduce the experimentation time and cost required for tuning these emissions. Hence, in this work, a 0D comprehensive predictive model has been formulated with selection and coupling of appropriate combustion and emissions models to engine cycle models. Selected combustion and emissions models are further modified to improve their prediction accuracy in the full operating zone. Responses of the combustion and emissions models have been validated for load and “start of injection” changes. Model predicted transient fuel consumption, air handling system parameters, and NOx and soot emissions are in good agreement with measured data on a turbocharged high power density common rail engine for the “nonroad transient cycle” (NRTC. It can be concluded that 0D models can be used for prediction of transient emissions on modern engines. How the formulated approach can also be extended to transient emissions prediction for other applications and fuels is also discussed.

  7. Estimating nitrogen oxides emissions at city scale in China with a nightlight remote sensing model.

    Science.gov (United States)

    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

  8. E. Plasma Catalysis for NOx Reduction from Light-Duty Diesel Vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Barlow, Stephan E.; Ebeling, Ana C.; Maupin, Gary D.; Balmer, M Lou; Panov, Alexander G.; Peden, Charles HF; Tonkyn, Russell G.; Epping, Kathy; Hoard, John W.; Cho, Byong; Schmieg, Steven J.; Brooks, David; Nunn, Steven; Davis, Patrick

    2001-11-19

    In this program, we have been developing a novel plasma/catalyst technology for the remediation of NOx under lean (excess oxygen) conditions, specifically for compression ignition direct injection (CIDI) diesel engines that have significant fuel economy benefits over conventional stoichiometric gasoline engines. Our previous work has shown that a non-thermal plasma in combination with an appropriate catalyst can provide NOx emission reduction efficiency of 60-80% using a simulated diesel exhaust. Based on these levels of NOx reduction obtained in the lab, a simple model was developed in this program last year that allows for the estimation of the fuel economy penalty that would be incurred by operating a plasma/catalyst system. Results obtained from this model suggest that a 5% fuel economy penalty is achievable with the then current state-of-the-art catalyst materials and plasma reactor designs.

  9. Modeling lightning-NOx chemistry on a sub-grid scale in a global chemical transport model

    Directory of Open Access Journals (Sweden)

    A. Gressent

    2016-05-01

    Full Text Available For the first time, a plume-in-grid approach is implemented in a chemical transport model (CTM to parameterize the effects of the nonlinear reactions occurring within high concentrated NOx plumes from lightning NOx emissions (LNOx in the upper troposphere. It is characterized by a set of parameters including the plume lifetime, the effective reaction rate constant related to NOx–O3 chemical interactions, and the fractions of NOx conversion into HNO3 within the plume. Parameter estimates were made using the Dynamical Simple Model of Atmospheric Chemical Complexity (DSMACC box model, simple plume dispersion simulations, and the 3-D Meso-NH (non-hydrostatic mesoscale atmospheric model. In order to assess the impact of the LNOx plume approach on the NOx and O3 distributions on a large scale, simulations for the year 2006 were performed using the GEOS-Chem global model with a horizontal resolution of 2° × 2.5°. The implementation of the LNOx parameterization implies an NOx and O3 decrease on a large scale over the region characterized by a strong lightning activity (up to 25 and 8 %, respectively, over central Africa in July and a relative increase downwind of LNOx emissions (up to 18 and 2 % for NOx and O3, respectively, in July. The calculated variability in NOx and O3 mixing ratios around the mean value according to the known uncertainties in the parameter estimates is at a maximum over continental tropical regions with ΔNOx [−33.1, +29.7] ppt and ΔO3 [−1.56, +2.16] ppb, in January, and ΔNOx [−14.3, +21] ppt and ΔO3 [−1.18, +1.93] ppb, in July, mainly depending on the determination of the diffusion properties of the atmosphere and the initial NO mixing ratio injected by lightning. This approach allows us (i to reproduce a more realistic lightning NOx chemistry leading to better NOx and O3 distributions on the large scale and (ii to focus on other improvements to reduce remaining uncertainties from processes

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

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

  11. CO2 , NOx and SOx removal from flue gas via microalgae cultivation: a critical review.

    Science.gov (United States)

    Yen, Hong-Wei; Ho, Shih-Hsin; Chen, Chun-Yen; Chang, Jo-Shu

    2015-06-01

    Flue gas refers to the gas emitting from the combustion processes, and it contains CO2 , NOx , SOx and other potentially hazardous compounds. Due to the increasing concerns of CO2 emissions and environmental pollution, the cleaning process of flue gas has attracted much attention. Using microalgae to clean up flue gas via photosynthesis is considered a promising CO2 mitigation process for flue gas. However, the impurities in the flue gas may inhibit microalgal growth, leading to a lower microalgae-based CO2 fixation rate. The inhibition effects of SOx that contribute to the low pH could be alleviated by maintaining a stable pH level, while NOx can be utilized as a nitrogen source to promote microalgae growth when it dissolves and is oxidized in the culture medium. The yielded microalgal biomass from fixing flue gas CO2 and utilizing NOx and SOx as nutrients would become suitable feedstock to produce biofuels and bio-based chemicals. In addition to the removal of SOx , NOx and CO2 , using microalgae to remove heavy metals from flue gas is also quite attractive. In conclusion, the use of microalgae for simultaneous removal of CO2 , SOx and NOx from flue gas is an environmentally benign process and represents an ideal platform for CO2 reutilization. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Development of METHANE de-NOX Reburn Process for Wood Waste and Biomass Fired Stoker Boilers - Final Report - METHANE de-NOX Reburn Technology Manual

    Energy Technology Data Exchange (ETDEWEB)

    J. Rabovitser; B. Bryan; S. Wohadlo; S. Nester; J. Vaught; M. Tartan (Gas Technology Institute); R. Glickert (ESA Environmental Solutions)

    2007-12-31

    The overall objective of this project was to demonstrate the effectiveness of the METHANE de-NOX® (MdN) Reburn process in the Forest Products Industry (FPI) to provide more efficient use of wood and sludge waste (biosolids) combustion for both energy generation and emissions reduction (specifically from nitrogen oxides (NOx)) and to promote the transfer of the technology to the wide range of wood waste-fired stoker boilers populating the FPI. This document, MdN Reburn Commercial Technology Manual, was prepared to be a resource to promote technology transfer and commercialization activities of MdN in the industry and to assist potential users understand its application and installation requirements. The Manual includes a compilation of MdN commercial design data from four different stoker boiler designs that were baseline tested as part of the development effort. Design information in the Manual include boiler CFD model studies, process design protocols, engineering data sheets and commercial installation drawings. Each design package is unique and implemented in a manner to meet specific mill requirements.

  13. Improvement study for the dry-low-NOx hydrogen micromix combustion technology

    Directory of Open Access Journals (Sweden)

    A. Haj Ayed

    2015-09-01

    Full Text Available The dry-low-NOx (DLN micromix combustion principle is developed for the low emission combustion of hydroge