Equilibria of the Reactions Between Nitrogen Oxides and the Sodium Carbonate

1994 ◽  
Vol 59 (3) ◽  
pp. 517-527
Author(s):  
Emerich Erdös ◽  
Karel Mocek
Keyword(s):  
Carbon Dioxide ◽  
Nitrogen Oxides ◽  
Nitrogen Dioxide ◽  
Sodium Carbonate ◽  
Nitrogen Monoxide ◽  
Point Of View ◽  
General Analysis ◽  
Gaseous Nitrogen ◽  
Chemical Equilibria ◽  
Partial Pressures

A general analysis of chemical equilibria in a system consisting of the gaseous nitrogen monoxide, nitrogen dioxide, carbon dioxide, oxygen and of the solid sodium carbonate is carried out with respect to the equilibrium partial pressures of nitrogen oxides. The pertaining equations are derived for three regions of existence of the above system. The results are represented graphically and discussed from the point of view of removing the nitrogen oxides from the waste gases.

Equilibria of Reactions Between Nitrogen Oxides and Calcium Hydroxide

1995 ◽  
Vol 60 (5) ◽  
pp. 751-762
Author(s):  
Emerich Erdös ◽  
Karel Mocek
Keyword(s):  
Carbon Dioxide ◽  
Water Vapor ◽  
Calcium Carbonate ◽  
Nitrogen Oxides ◽  
Calcium Hydroxide ◽  
Nitrogen Monoxide ◽  
Equilibrium Equations ◽  
Gaseous Nitrogen ◽  
Chemical Equilibria ◽  
Partial Pressures

A general analysis of chemical equilibria in a system consisting of the gaseous nitrogen monoxide, nitrogen dioxide, water vapor, carbon dioxide, oxygen, and the solid calcium hydroxide is carried out with respect to the equilibrium partial pressures of nitrogen oxides. The conditions are defined, under which the calcium hydroxide is transformed to the calcium carbonate. The corresponding equilibrium equations are derived for all nine regions of existence of described system. The results are illustrated graphically and discussed from the point of removing the nitrogen oxides from waste gases.

Reactivity of Nitrogen Oxides Towards Sodium Carbonate and Hydrogencarbonate Based Solid Sorbents

1996 ◽  
Vol 61 (12) ◽  
pp. 1709-1714
Author(s):  
Erich Lippert ◽  
Pavel Bach ◽  
Květoslava Stejskalová ◽  
Emerich Erdös ◽  
Karel Mocek
Keyword(s):  
Carbon Dioxide ◽  
Water Vapor ◽  
Nitrogen Oxides ◽  
Nitrogen Dioxide ◽  
Sodium Carbonate ◽  
Nitrogen Monoxide ◽  
Reaction Products ◽  
Solid Sorbents ◽  
Lower Reactivity ◽  
Technological Interest

The reactivity of nitrogen oxides towards sodium carbonate and hydrogencarbonate based solids was measured within a range of variables which is of technological interest. The reactivity is significant at lower temperatures only and is not affected by the presence of carbon dioxide or oxygen. Water vapor acts as a catalyst. Nitrogen dioxide is more reactive than nitrogen monoxide. The reactivity of the solid depends substantially on its origin and way of preparation. As compared with SO2 or HCl, nitrogen oxides exhibit a lower reactivity, presumably because the solid is blocked by the reaction products.

scholarly journals Air pollution by nitrogen oxides in Sarajevo from 2005 to 2010

2013 ◽  
Vol 3 (3) ◽  
pp. 250-254
Author(s):  
Suad Habeš ◽  
Zarema Obradović ◽  
Aida Ridžal ◽  
Asmir Aldžić
Keyword(s):  
Air Pollution ◽  
Nitrogen Oxides ◽  
Positive Result ◽  
Nitrogen Dioxide ◽  
Total Concentration ◽  
Nitrogen Monoxide ◽  
Atmospheric Conditions ◽  
Measuring Point ◽  
Limit Values ◽  
Research Show

Introduction: Air pollution occurs when the concentration of certain substances (pollutants) reaches a size which causes its toxicity, or in other words, begins to cause harm to human health, fl ora and wildlife.Methods: Measurements were performed in the period from 2005 to 2010, at the measuring point Bjelave-Sarajevo by the method of Griess-Saltzmann. It encompasses the following parameters: NO, NO2, NOx, measured concentrations of pollutants in the atmosphere reduced to normal atmospheric conditions of 293 K (Kelvin) and pressure of 101.3 kPa (kilopascal).Results: NO concentration in the period from 2005 to 2008 was above the permitted value, but the results of research in the period between 2009 and 2010, have shown that there was a decrease in NO concentration in the atmosphere. Measurements show that the concentration of this pollutant is currently declining, which is a positive result compared to the pollution of the atmosphere by nitrogen monoxide. Furthermore, the results of the research showed that the concentration of NO2 for the period of 2005 to 2010, is in the limited values, and that has a decreasing trend, which is also a positive result compared to the pollution of the atmosphere by nitrogen dioxide. Related to the total concentration of NOx in the atmosphere, the results of the research show that their representation corresponds to the limit values existing in the Rulebook on limit values for air quality.Conclusion: The results of the research for the pollution of the atmosphere by nitrogen oxides in the investigated area show that the amount of nitrogen oxides in the atmosphere is in constant decline.

scholarly journals Low-Speed Marine Diesel Engine Modeling for NOx Prediction in Exhaust Gases

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4442
Author(s):  
Branko Lalić ◽  
Andrijana Poljak ◽  
Gojmir Radica ◽  
Antonija Mišura
Keyword(s):  
Diesel Engine ◽  
Nitrogen Oxides ◽  
Nitrogen Dioxide ◽  
Nitrogen Oxide ◽  
Fuel Consumption ◽  
Compression Ratio ◽  
Fuel Injection ◽  
Nitrogen Monoxide ◽  
Exhaust Emissions ◽  
Injection Timing

Knowing the process of generating exhaust emissions and the determination of influential parameters are important factors in improving two-stroke slow-speed marine engines, particularly for further reductions in fuel consumption and stringent regulations on the limitation of nitrogen oxide emissions. In this article, a model of a marine low-speed two-stroke diesel engine has been developed. Experimental and numerical analyses of the nitrogen monoxide formations were carried out. When measuring the concentration of nitrogen oxides in the exhaust emissions, the amount of nitrogen dioxide (NO2) is usually measured, because nitrogen monoxide is very unstable, and due to the large amount of oxygen in the exhaust gases, it is rapidly converted into nitrogen dioxide and its amount is included in the total emission of nitrogen oxides. In this paper, the most significant parameters for the formation of nitrogen monoxide have been determined. Model validation was performed based on measured combustion pressures, engine power, and concentrations of nitrogen oxides at 50% and 75% of maximum continuous engine load. The possibilities of fuel consumption optimization and reduction in nitrogen monoxide emissions by correcting the injection timing and changing the compression ratio were examined. An engine model was developed, based on measured combustion pressures and scavenging air flow, to be used on board by marine engineers for rapid analyses and determining changes in the concentration of nitrogen oxides in exhaust emissions. The amount of nitrogen oxide in exhaust emissions is influenced by the relevant features described in this paper: fuel injection timing and engine compression ratio. The presented methodology provides a basis for further research about the simultaneous impact of changing the injection timing and compression ratio, exhaust valve opening and closing times, as well as the impact of multiple fuel injection to reduce consumption and maintain exhaust emissions within the permissible limits.

scholarly journals Mechanism of the oxidation of nitric oxide with oxygen

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Józef Głowiński ◽  
Józef Hoffmann ◽  
Marcin Wilk
Keyword(s):  
Nitric Oxide ◽  
Nitrogen Oxides ◽  
Nitrogen Dioxide ◽  
Gas Phase ◽  
Oxidation Reaction ◽  
Nitrogen Monoxide ◽  
Fast Reactions

Abstract Very fast reactions of forming higher nitrogen oxides set out an equilibrium framework for the course of the reaction of nitrogen monoxide oxidation. The slow course of reaction of nitrogen monoxide with oxygen permanently violates the created equilibria. In particular, the equilibrium of the oxidation reaction of nitrogen monoxide with nitrogen dioxide. The contribution of this reaction to the transformation of nitrogen monoxide in the conditions of nitrogen trioxide removal from the gas phase was estimated.

Intercomparison of nitrogen monoxide and nitrogen dioxide measurements in the atmosphere simulation chamber SAPHIR during the MetNO2 campaign

2020 ◽  
Author(s):  
Robert Wegener ◽  
Keyword(s):  
Nitrogen Oxides ◽  
Nitrogen Dioxide ◽  
Gas Phase ◽  
Nitrogen Monoxide ◽  
Ambient Air ◽  
Alkyl Nitrates ◽  
Dinitrogen Pentoxide ◽  
Laser Absorption ◽  
Calibration Techniques ◽  
Atmosphere Simulation Chamber

<p>Nitrogen dioxide (NO<sub>2</sub>) and nitrogen monoxide (NO) govern the photochemical processes in the troposphere. Although nitrogen oxides have been measured for decades, their quantification remains challenging. The MetNO2 (Metrology for Nitrogen Dioxide) project of the European Metrology Programme for Innovation and Research (EMPIR) aims to improve the accuracy of NO<sub>2</sub> measurements.</p><p>In total 15 instruments were intercompared at the World Calibration Centre for nitrogen oxides (WCC-NOx) in Jülich in autumn 2019 within the project. In addition to chemiluminescence detectors (CLD), the instruments encompassed Quantum Cascade Laser Absorption Spectrometers (QCLAS), Iterative CAvity-enhanced Differential optical absorption spectrometers (ICAD) and Cavity Attenuated Phase Shift (CAPS) spectrometers.</p><p>During the campaign, air from a gas phase titration unit, air from the environmental chamber SAPHIR or outside air was provided to the instruments via a common inlet line. The participants calibrated their instruments prior and after the campaign with their own calibration procedures. During the campaign, the common inlet line was used for daily calibration to compare standards, calibration techniques and sensitivity drifts of the instruments. NO<sub>2</sub> for calibration was provided either by gas phase titration from NO, from permeation tubes or from gas mixtures produced within the MetNO2 project.</p><p>It was observed that measurements by chemiluminescence or CAPS instruments are prone to interferences from humidity and ozone. However, in most cases data can be corrected. Alkyl nitrates and reactive alkenes were also observed to cause interferences in some instruments, while isobutyl nitrite was found to be photolyzed by photolytic converters.</p><p>Finally, measurements in ambient air were compared. The nitrogen oxide observations were accompanied with measurements of hydroxyl radical (OH) reactivity and reactive nitrogen species as nitrous acid (HONO), dinitrogen pentoxide (N<sub>2</sub>O<sub>5</sub>), and chloryl nitrate (ClNO<sub>2</sub>). Detailed results of the intercomparison will be presented.</p>

Effects of the Gas Phase Composition and Genesis of the Active Sodium Carbonate on Its Reactivity Towards Gaseous Mixture SO2 + NOx

1997 ◽  
Vol 62 (3) ◽  
pp. 387-391
Author(s):  
Květoslava Stejskalová ◽  
Pavel Bach ◽  
Erich Lippert ◽  
Karel Mocek
Keyword(s):  
Carbon Dioxide ◽  
Gas Phase ◽  
Sodium Carbonate ◽  
Flow Reactor ◽  
Fixed Bed ◽  
Gaseous Mixture ◽  
Solid Substance ◽  
Integral Conditions ◽  
Active Sodium ◽  
Partial Pressures

The reactivity of the solid active sodium carbonate towards gaseous mixture SO2 + NOx has been measured in the dependence on oxygen and carbon dioxide contents and on genesis of the solid substance. The fixed bed flow reactor working under integral conditions has been used. It was found that the reactivity of the active sodium carbonate of the 1st generation towards gaseous mixture SO2 + NOx is higher than the reactivity of the active sodium carbonate of the 2nd generation. In the temperature range of 130-180 °C the partial pressures of oxygen and carbon dioxide have no decisive influence on the reactivity of the active sodium carbonate of the 1st generation.

scholarly journals Alternative Exhaust Emission Factors from Vehicles in On-Road Driving Tests

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3487
Author(s):  
Wojciech Gis ◽  
Maciej Gis ◽  
Jacek Pielecha ◽  
Kinga Skobiej
Keyword(s):  
Carbon Dioxide ◽  
Nitrogen Oxides ◽  
Particle Number ◽  
Exhaust Emission ◽  
The European Union ◽  
Environmental Aspects ◽  
Vehicle Category ◽  
Urban Rural ◽  
European Union Legislation ◽  
Do So

On-road driving tests are performed to determine the emission of harmful exhaust compounds from vehicles. These primarily include carbon dioxide, nitrogen oxides, and particle number. However, there is a lack of indicators that combine the first three substances that are the most important in assessing the environmental aspects of vehicles. The purpose of this article is to indicate the possibility of assessing emissions in real driving conditions from light-duty and heavy-duty vehicles of different categories. In order to do so, a portable emissions measurement system (PEMS) and an instrument for measuring the particle number were used. The tests were carried out on routes designed to comply with the requirements and regulations laid down in the European Union legislation. On-road emissions of carbon dioxide, nitrogen oxides and particle number have been determined. Factors have been determined as the multiplication of these compounds for each vehicle category in three phases of the test: urban, rural, and motorway. A new way of assessing emissions from vehicles using new factors has been proposed.

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