scholarly journals Indoor Nitrogen Oxides

10.5772/16819 ◽  
2011 ◽  
Author(s):  
Silvia Vilcekova
Keyword(s):  
Nitrogen Oxides

WET BURNING – THE MODERN TREND IN ENVIRONMENTAL BENIGN FUEL COMBUSTION AND IN SOLUTION TO THE PROBLEM OF SUSTAINABLE DEVELOPMENT OF THE POWER GENERATION

2018 ◽  
pp. 96-117 ◽  
Author(s):  
B. S. Soroka
Keyword(s):  
Numerical Simulation ◽  
Nitrogen Oxides ◽  
Chemical Kinetics ◽  
Fuel Combustion ◽  
Transport Processes ◽  
Cfd Modeling ◽  
Furnace Chamber ◽  
Modern Trend ◽  
Atmospheric Air ◽  
No Formation

The article considers the role and place of water and water vapor in combustion processes with the purpose of reduction the effluents of nitrogen oxides and carbon oxide. We have carried out the complex of theoretical and computational researches on reduction of harmful nitrogen and carbon oxides by gas fuel combustion in dependence on humidity of atmospheric air by two approaches: CFD modeling with attraction of DRM 19 chemical kinetics mechanism of combustion for 19 components along with Bowman’s mechanism used as “postprocessor” to determine the [NO] concentration; different thermodynamic models of predicting the nitrogen oxides NO formation. The numerical simulation of the transport processes for momentum, mass and heat being solved simultaneously in the united equations’ system with the chemical kinetics equations in frame of GRI methane combustion mechanism and NO formation calculated afterwards as “postprocessor” allow calculating the absolute actual [CO] and [NO] concentrations in dependence on combustion operative conditions and on design of furnace facilities. Prediction in frame of thermodynamic equilibrium state for combustion products ensures only evaluation of the relative value of [NO] concentration by wet combustion the gas with humid air regarding that in case of dry air – oxidant. We have developed the methodology and have revealed the results of numerical simulation of impact of the relative humidity of atmospheric air on harmful gases formation. Range of relative air humidity under calculations of atmospheric air under impact on [NO] and [CO] concentrations at the furnace chamber exit makes φ = 0 – 100%. The results of CFD modeling have been verified both by author’s experimental data and due comparing with the trends stated in world literature. We have carried out the complex of the experimental investigations regarding atmospheric air humidification impact on flame structure and environmental characteristics at natural gas combustion with premixed flame formation in open air. The article also proposes the methodology for evaluation of the nitrogen oxides formation in dependence on moisture content of burning mixture. The results of measurements have been used for verification the calculation data. Coincidence of relative change the NO (NOx) yield due humidification the combustion air revealed by means of CFD prediction has confirmed the qualitative and the quantitative correspondence of physical and chemical kinetics mechanisms and the CFD modeling procedures with the processes to be studied. A sharp, more than an order of reduction in NO emissions and simultaneously approximately a two-fold decrease in the CO concentration during combustion of the methane-air mixture under conditions of humidification of the combustion air to a saturation state at a temperature of 325 K.

Considerations on Ambient Levels of Ozone Concentrations and Relationship with NOx in an Urban Environment

2017 ◽  
Vol 68 (4) ◽  
pp. 824-829
Author(s):  
Cornel Ianache ◽  
Laurentiu Predescu ◽  
Mirela Predescu ◽  
Dumitru Dumitru
Keyword(s):  
Nitrogen Oxides ◽  
Urban Areas ◽  
Road Traffic ◽  
Temporal Distribution ◽  
Ground Level ◽  
Distinct Pattern ◽  
Weekend Effect ◽  
Monitoring Site ◽  
Ground Level Ozone ◽  
Ozone Concentrations

The serious air pollution problem has determined public concerns, worldwide. One of the main challenges for countries all over the world is caused by the elevated levels of ground-level ozone (O3) concentrations and its anthropogenic precursors. Ploiesti city, as one of the major urban area of Romania, is facing the same situation. This research aims to investigate spatial and temporal distribution characteristics of O3 in relationship with nitrogen oxides (NOx) using statistical analysis methods. Hourly O3 and NOx measurements were collected during 2014 year in Ploiesti. The results obtained showed that the ozone spatial distribution was non-normal for each month in 2014. The diurnal cycle of ground-level ozone concentrations showed a mid-day peak, while NOx diurnal variations presented 2 daily peaks, one in the morning (7:00 a.m.) and one in the afternoon (between 5:00 and 7:00 p.m.). In addition, it was observed a distinct pattern of weekly variations for O3 and NOx. Like in many other urban areas, the results indicated the presence of the �ozone weekend effect� in Ploiesti during the 2014 year, ozone concentrations being slightly higher on weekends compared to weekdays. For the same monitoring site, the nitrogen oxides were less prevalent on Saturdays and Sundays, probably due to reducing of road traffic and other pollution-generating activities on weekends than during the week.

Formation and destruction of nitrogen oxides in coal combustion: Sixth quarterly report, April 1, 1989--June 30, 1989

1989 ◽  
Author(s):  
Wei-Yin Chen ◽  
T. W. Lester ◽  
L. M. Babcock ◽  
T. E. Burch ◽  
F. R. Tillman
Keyword(s):  
Nitrogen Oxides ◽  
Coal Combustion

scholarly journals Research Progress on Photocatalytic/Photoelectrocatalytic Oxidation of Nitrogen Oxides

2021 ◽  
Author(s):  
Shuangjun Li ◽  
Linglong Chen ◽  
Zhong Ma ◽  
Guisheng Li ◽  
Dieqing Zhang
Keyword(s):  
Nitrogen Oxides ◽  
Photocatalytic Oxidation ◽  
Research Progress ◽  
Future Directions ◽  
Inorganic Semiconductors ◽  
Photoelectrocatalytic Oxidation ◽  
Low Concentrations ◽  
Photocatalytic System ◽  
Metal Organic ◽  
Oxidation Of No

AbstractThe emission of nitrogen oxides (NOx) increases year by year, causing serious problems to our livelihoods. The photocatalytic oxidation of NOx has attracted more attention recently because of its efficient removal of NOx, especially for low concentrations of NOx. In this review, the mechanism of the photocatalytic oxidation of NOx is described. Then, the recent progress on the development of photocatalysts is reviewed according to the categories of inorganic semiconductors, bismuth-based compounds, nitrogen carbide polymer, and metal organic frameworks (MOFs). In addition, the photoelectrocatalytic oxidation of NOx, a method involving the application of an external voltage on the photocatalytic system to further increase the removal efficiency of NOx, and its progress are summarized. Finally, we outline the remaining challenges and provide our perspectives on the future directions for the photocatalytic oxidation of NOx.

Air quality and synergistic health effects of ozone and nitrogen oxides in response to China’s integrated air quality control policies during 2015–2019

Chemosphere ◽  
2021 ◽  
Vol 268 ◽  
pp. 129385
Author(s):  
Xuguo Zhang ◽  
Jimmy C.H. Fung ◽  
Alexis K.H. Lau ◽  
Md Shakhaoat Hossain ◽  
Peter K.K. Louie ◽  
...  
Keyword(s):  
Quality Control ◽  
Air Quality ◽  
Nitrogen Oxides ◽  
Health Effects ◽  
Control Policies ◽  
Air Quality Control
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