Kinetics of forming the nitrogen oxides and other harmful substances in catalytic power plants

2004 ◽  
Vol 22 (1) ◽  
pp. 71
Author(s):  
F.A. Polyvoda ◽  
V.I. Kabakov
Keyword(s):  
Nitrogen Oxides ◽  
Power Plants ◽  
Harmful Substances ◽  
Kinetics Of ◽  
Catalytic Power

Modeling of a dry low nitrogen oxides burner using a three-dimensional computational fluid dynamics simulation

2021 ◽  
pp. 095440892110355
Author(s):  
Guodong Sun ◽  
Xuejing Duan ◽  
Bo Hao ◽  
Afshin Davarpanah
Keyword(s):  
Nitrogen Oxides ◽  
Greenhouse Gases ◽  
Power Plants ◽  
Three Dimensional ◽  
Control Policy ◽  
Dynamics Simulation ◽  
Weather Patterns ◽  
United Nations General ◽  
Fluent Software ◽  
Low Nitrogen

Nitrogen oxides are considered as one of the greenhouse gases. Among the most significant emission sources for this gas is a natural gas-fired power plant. The United Nations General assembly suggested in 1988 that human activities can negatively impact weather patterns, and thus they should be controlled. This control policy can improve the efficiency of final consumers such as power plants, cars, or other energy-intensive industries. In this paper, the existing strategies and explicitly making the dry low nitrogen oxides burner reduce greenhouse gases in power plants are explored. The geometry of the burner has been produced in a three-dimensional form in GAMBIT software, and the results of the simulation have been expressed through FLUENT software. Contours of pressure, temperature, and velocity of the fluid in the furnace are also derived. It is concluded that the dry low nitrogen oxides burners plan has a better result compared with other strategies.

scholarly journals STUDY OF THE OXIDATION PROCESS OF NITROGEN OXIDES BY OZONE

2021 ◽  
pp. 62-70
Author(s):  
I.A. Volchyn ◽  
O.M. Kolomiets ◽  
S.V. Mezin ◽  
A.O. Yasynetskyi
Keyword(s):  
Nitrogen Oxides ◽  
Conversion Efficiency ◽  
Power Plants ◽  
Oxidation Process ◽  
Thermal Power ◽  
Nitrogen Monoxide ◽  
Molar Ratio ◽  
Gas Temperature ◽  
Gas Treatment ◽  
Industrial Enterprises

The need to reduce emissions of pollutants, in particular nitrogen oxides, as required by regulations in Ukraine, requires the use of modern technologies and methods for waste gas treatment at industrial enterprises. This is especially true of thermal power plants, which are powerful sources of nitrogen oxide emissions. The technological part of the wet or semi-dry method of purification is the area for the oxidation of nitrogen oxides to obtain easily soluble compounds. The paper presents the results of a study of the process of ozone oxidation of nitrogen oxides in a chemical reactor. Data for the analysis of the process were obtained by performing physical experiments on a laboratory installation and related calculations on a mathematical model. Studies of the oxidation process have shown that the required amount of ozone depends not only on the content of nitrogen monoxide, but also on the content of nitrogen dioxide. The process of conversion of nitrogen monoxide to a satisfactory level occurs at the initial value of the molar ratio of ozone to nitrogen monoxide in the range of 1.5…2. The conversion efficiency of nitrogen monoxide reaches 90% at a gas temperature less than 100 °C. To achieve high conversion efficiency at gas temperatures above 100 °C, it is necessary to increase the initial ozone content when the molar ratio exceeds 2. The analysis shows that the conversion efficiency of nitric oxide largely depends on the residence time of the gas mixture in the reaction zone. Due to lack of time under certain conditions, the efficiency decreases by approximately 46%. To increase it, it is necessary to accelerate the rate of oxidation reactions due to better mixing of gases by turbulence of the flow in the oxidizing reactor. Bibl. 6, Fig. 6, Tab. 3.

scholarly journals Ensuring Requirements for Emissions of Harmful Substances of Diesel Engines

2020 ◽  
Vol 19 (4) ◽  
pp. 305-310
Author(s):  
G. M. Kuharonak ◽  
D. V. Kapskiy ◽  
V. I. Berezun
Keyword(s):  
Diesel Engine ◽  
Nitrogen Oxides ◽  
Fuel Consumption ◽  
Exhaust Gas Recirculation ◽  
Exhaust Gas ◽  
Average Temperature ◽  
Dispersed Particles ◽  
Harmful Substances ◽  
Gas Recirculation ◽  
Emissions Of Harmful Substances

The purpose of this work is to consider the requirements for emissions of harmful substances of diesel engines by selecting design and adjustment parameters that determine the organization of the workflow, and the exhaust gas cleaning system, taking into account the reduction of fuel consumption. Design elements and geometric characteristics of structures for a turbocharged diesel engine of Д-245 series produced by JSC HMC Minsk Motor Plant (4ЧН11/12.5) with a capacity of 90 kW equipped with an electronically controlled battery fuel injection have been developed: exhaust gas recirculation along the high pressure circuit, shape and dimensions of the combustion chamber, the number and angular arrangement of the nozzle openings in a nozzle atomizer, and inlet channels of the cylinder head. Methods for organizing a workflow are proposed that take into account the shape of the indicator diagrams and affect the emissions of nitrogen oxides and dispersed particles differently. Their implementation allows us to determine the boundary ranges of changes in the control parameters of the fuel supply and exhaust gas recirculation systems when determining the area of minimizing the specific effective fuel consumption and the range of studies for the environmental performance of a diesel engine. The paper presents results of the study on the ways to meet  the requirements for emissions of harmful substances, obtained by considering options for the organization of working processes, taking into account the reduction in specific effective fuel consumption, changes in the average temperature of the exhaust gases and diesel equipment. To evaluate these methods, the following indicators have been identified: changes in specific fuel consumption and average temperature of the toxicity cycle relative to the base cycle, the necessary degree of conversion of the purification system for dispersed particles and NOx. Recommendations are given on choosing a diesel engine to meet Stage 4 emission standards for nitrogen oxides and dispersed particles.

scholarly journals ЗМЕНШЕННЯ ВИКИДІВ СУДНОВОГО ДИЗЕЛЯ УТИЛІЗАЦІЄЮ ТЕПЛОТИ РЕЦИРКУЛЯЦІЙНИХ ГАЗІВ ЕЖЕКТОРНОЮ ХОЛОДИЛЬНОЮ МАШИНОЮ

2019 ◽  
pp. 20-24
Author(s):  
Максим Андрійович Пирисунько ◽  
Роман Миколайович Радченко ◽  
Андрій Адольфович Андреєв ◽  
Вікторія Сергіївна Корнієнко
Keyword(s):  
Nitrogen Oxides ◽  
Alternative Fuels ◽  
Exhaust Gas ◽  
Exhaust Gases ◽  
Harmful Emissions ◽  
Harmful Substances ◽  
Main Engine ◽  
Gas Recirculation ◽  
Refrigeration Machine ◽  
Emissions Of Harmful Substances

The problem of air basin pollution of the World Ocean with harmful emissions from the exhaust gases of marine diesel engines is primarily associated with the creation of highly efficient technologies for the neutralization of nitrogen oxides NOx on exhaust gases from a diesel engine. Emissions of harmful substances from the combustion of marine fuels are limited by international atmospheric protection programs and the requirements of the International Maritime Organization (IMO). The requirements relate to almost all groups of harmful emissions in marine engines and the more stringent of them are primarily related to nitrogen oxides NOx and sulfur oxides SOx. To reduce harmful emissions from exhaust gases into the environment, scientists and world engine leaders use and suggest various methods for reducing the content of harmful substances in exhaust gases. The implementation of new standards in the areas of further improvement of the working process, the use of alternative fuels, fuel, and air additives, as well as selective catalytic reduction systems do not preclude further development of scientific research in the field of exhaust gas cleaning. One of the promising ways in environmentalizing marine internal combustion engines is the neutralization of harmful substances in exhaust gases through particular gas recirculation (EGR-technology). However, the use of such techniques conflicts with the engine's energy efficiency. In the work presented, the scheme-design solution of the exhaust gas recirculation system with using the heat of recirculation gases by an ejector refrigeration machine for cooling the air at the intake of ship's main engine is proposed. The effect of using the heat of recirculation gases for cooling the air at the intake of the engine is analyzed taking into account the changing climatic conditions for a particular vessel's route line. It is shown that the use of an ejector refrigeration machine reduces the air temperature at the entrance of the main engine by 5…15 ° С, which reduces the specific fuel consumption. This reduces emissions of harmful substances when the engine is running with recirculation of gases.

Environmental indicators of modern land vehicles

2020 ◽  
Keyword(s):  
Control System ◽  
Nitrogen Oxides ◽  
Greenhouse Effect ◽  
Power Plants ◽  
Catalytic Converter ◽  
Exhaust System ◽  
Environmental Indicators ◽  
Solid Particles ◽  
Particulate Filter ◽  
Land Vehicles

Models and mechanisms for the formation of soot and nitrogen oxides during the combustion of hydrocarbon fuels of power plants of vehicles have been developed. Models of numerical modeling and calculation of solid particles, nitrogen oxides and urea of diesel engines are formulated. The potential for the formation of a greenhouse effect is briefly described. The regularity of the relationship between nitrogen oxides and soot was revealed. A schematic diagram of the oxidizing neutralizer and particulate filter of modern diesel is given. The diagram of the urea supply system and the urea atomization module in the engine exhaust system is given. The scheme of the control system for catalytic neutralization of nitrogen oxides is given. A comparative assessment of nitric oxide reductants is given. An assessment of the technical and environmental effectiveness of the system for reducing the toxicity and smoke content of modern engines is given. Keywords greenhouse effect, smokiness, solid particles, urea, soot, diesel, acetylene, soot filter, catalytic Converter, nitrogen oxides, models for calculating soot and nitrogen oxides, urea supply module, control system

scholarly journals Impact of Control Measures on Nitrogen Oxides, Sulfur Dioxide and Particulate Matter Emissions from Coal-Fired Power Plants in Anhui Province, China

Atmosphere ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 35 ◽  
Author(s):  
Haitao Dai ◽  
Dawei Ma ◽  
Renbin Zhu ◽  
Bowen Sun ◽  
Jun He
Keyword(s):  
Particulate Matter ◽  
Sulfur Dioxide ◽  
Nitrogen Oxides ◽  
River Basin ◽  
Power Plants ◽  
Air Pollutant ◽  
Control Measures ◽  
Pollutant Emissions ◽  
Huai River ◽  
The Impact

Anhui is one of the highest provincial emitters of air pollutants in China due to its large coal consumption in coal-fired plants. In this study, the total emissions of nitrogen oxides (NOx), sulfur dioxide (SO2) and particulate matter (PM) from coal-fired power plants in Anhui were investigated to assess the impact of control measures on the atmospheric emissions based upon continuous emission monitoring systems (CEMS). The total NOx, SO2 and PM emissions significantly decreased from 2013 to 2017 and they were estimated at 24.5 kt, 14.8 kt and 3.0 kt in 2017, respectively. The emission reductions of approximately 79.0%, 70.1% and 81.2% were achieved in 2017 compared with a 2013 baseline, respectively, due to the application of high-efficiency emission control measures, including the desulfurization, denitration and dust-removing devices and selective catalytic reduction (SCR). The NOx, SO2 and PM emission intensities were 0.125 g kWh−1, 0.076 g kWh−1 and 0.015 g kWh−1 in 2017, respectively, which were lower than the average of national coal-fired units. The coal-fired units with ≥600 MW generated 80.6% of the total electricity amount while they were estimated to account for 70.5% of total NOx, 70.1% of total SO2 and 71.9% of total PM. Their seasonal emissions showed a significant correlation to the power generation with the maximum correlation found in summer (July and August) and winter (January and December). The major regional contributors are the cities along the Huai River Basin and Yangtze River Basin, such as Huainan, Huaibei, Tongling, Maanshan and Wuhu, and the highest emission occurred in Huainan, accounting for approximately 26–40% of total emission from all the power plants. Our results indicated that the application of desulfurization, denitration and dust-removing devices has played an important role in controlling air pollutant emissions from coal-fired power plants.

To the Problem of Reducing the Amount of Harmful Emissions when Refining Silver

2018 ◽  
Vol 284 ◽  
pp. 877-881
Author(s):  
Sergey E. Polygalov ◽  
S.A. Mastugin ◽  
E.A. Shadrina
Keyword(s):  
Nitric Acid ◽  
Nitrogen Oxides ◽  
Dissolution Rate ◽  
Rotating Disk ◽  
Oxidation Potential ◽  
Solution Temperature ◽  
Harmful Emissions ◽  
Environmentally Friendly Process ◽  
Silver Dissolution ◽  
Kinetics Of

The work is devoted to the study of the possibilities of minimizing the release of nitrogen oxides during the dissolution of silver in nitric acid solutions during refining of the gold and silver alloy. Using a rotating disk, the maximum concentration of nitric acid is determined, at which the oxidation potential of the system is insufficient for the oxidation of silver. It has been established that at a temperature of 363 K and a concentration of HNO3 = 50 g/l, the dissolution rate of silver does not exceed 0.00022∙10-5 mol/(cm2∙s), and such conditions can be considered as background for an environmentally friendly process. To initiate dissolution, hydrogen peroxide was used as an alternative oxidizing agent. As a criterion for the rational use of the oxidant and the ecological purity of the process, the excess pressure over the solution was evaluated. The influence of the initial and current composition of the solution, temperature, and conditions of oxidant supply to the reactor on the kinetics of the target process was studied. It is shown that at a silver dissolution rate of 2.7∙10-6 mol/(cm2∙s), no release of nitrogen oxides was observed.

Kinetics of nitric oxide oxidation

2010 ◽  
Vol 64 (2) ◽  
Author(s):  
Kinga Skalska ◽  
Jacek Miller ◽  
Stanisław Ledakowicz
Keyword(s):  
Nitric Oxide ◽  
Nitrogen Oxides ◽  
Emission Reduction ◽  
Nox Emission ◽  
Solubility In Water ◽  
The Third ◽  
Emission Regulations ◽  
Global Concern ◽  
Removal Technologies ◽  
Kinetics Of

AbstractNitrogen oxides are nowadays a subject of global concern. Several types of nitrogen oxides exist in the environment: N2O, NO, NO2, N2O3, N2O4, N2O5. The abbreviation NOx usually relates to nitric oxide NO, nitrogen dioxide NO2, and nitrous oxide N2O. The first two are harmful pollutants for both environment and human health, whereas the third is one of the greenhouse gases. Implementation of stringent NOx emission regulations requires the development of new NOx removal technologies from exhaust gases. One of many proposals for NOx emission reduction is the application of an oxidizing agent which would transform NOx to higher nitrogen oxides with higher solubility in water. The main objective of the paper was to present the rate constant of nitric oxide oxidation, determined in our studies.

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