scholarly journals Numerical simulation of nitrogen oxide formation in dust furnaces

2022 ◽  
pp. 23-33
Author(s):  
Bulbul Ongar ◽  
Hristo Beloev ◽  
Iliya Iliev ◽  
Assem Ibrasheva ◽  
Anara Yegzekova
Keyword(s):  
Air Pollution ◽  
Nitrogen Oxides ◽  
Nitrogen Oxide ◽  
Power Plants ◽  
Coal Dust ◽  
Thermal Power ◽  
Initial Section ◽  
Anthropogenic Sources ◽  
Sulphur Compounds ◽  
Coal Particles

Even though natural sources of air pollution account for over 50 % of sulphur compounds, 93 % of nitrogen oxide which are the most dangerous artificial anthropogenic sources of air pollution and primarily associated with the combustion of fossil fuel. Coal-fired thermal power plants and industrial fuel-burning plants that emit large quantities of nitrogen oxides (NО and NО2), solids (ash, dust, soot), as well as carbon oxides, aldehydes, organic acids into the atmosphere pollute the environment in majority. In the present work, a mathematical model and a scheme for calculating the formation of nitrogen oxide has been developed. Also, the dependence of the rate of release of fuel nitrogen from coal particles at the initial stage of gasification and content of volatiles has been obtained. The main regularities of the formation of NOx at the initial section of the flame in the ignition zone of the swirl burner flame during the combustion of Ekibastuz coal have been revealed. Modern environmental requirements for the modernization of existing and the creation of new heat and power facilities determine the exceptional relevance of the development of effective methods and constructions to reduce emissions of nitrogen oxides, sulfur oxides and ash to 200, 300, and 100 mg/nm3 at a=1.4. The dust consumption in all experiments was kept constant and amounted to 0.042 g/s, as well as with the results of calculating the thermal decomposition of the Ekibastuz coal dust, the recombination of atomic nitrogen into nitrogen molecules, and the kinetics of the formation of fuel nitric oxide. It was found that despite the presence of oxygen in Ekibastuz coal for gases Odaf=11.8 % in an inert atmosphere, nitrogen oxides are not formed

scholarly journals Methods for reducing nitrogen oxide emissions in steam generators of thermal power plants

2021 ◽  
Vol 81 (1) ◽  
pp. 111-116
Author(s):  
A. Plevako ◽  
Keyword(s):  
Nitrogen Oxides ◽  
Nitrogen Oxide ◽  
Steam Generator ◽  
Power Plants ◽  
Thermal Power ◽  
Environmental Safety ◽  
Flue Gases ◽  
Thermal Power Plants ◽  
Steam Generators ◽  
Nitrogen Oxide Emissions

Main problem: Ensuring environmental safety of thermal power plants by reducing emissions of harmful substances, in particular nitrogen oxides. When all types of fossil fuel, including solid fuel, are burned, nitrogen oxides are formed in the boilers of TPPs. The sources of their formation are air nitrogen and nitrogen- containing components of the organic matter of the fuel. As you know, they adversely affect the health of humans, plants and animals. Therefore, it became necessary to consider and analyze methods to reduce these emissions. Purpose: To review and analyze various ways to reduce nitrogen oxide emissions and propose a new scheme for reducing these emissions by recirculating flue gases. Methods: This is achieved due to the fact that in the known method for purifying the flue gases of steam generators from nitrogen oxides by lowering the temperature in the furnace of the steam generator by supplying flue gases with a temperature below the temperature in the furnace of the steam generator, it is proposed that the flue gases be fed into the furnace of the steam generator after ash cleaning. At the same time, as a result of the supply of recirculated gas cooled after filtering and passing through the main smoke exhauster into the combustion chamber, having a temperature of 110-170 °C, in comparison with the initial version, a greater decrease in temperature in the furnace of the steam generator occurs, which in turn leads to a decrease in the flue gases of oxides nitrogen, since the chemical reaction of their formation goes with the absorption of heat. Results and their importance: The technical result at the proposed method of cleaning from nitrogen oxides is to reduce the consumption of electricity by eliminating the collateral wear of the recirculation gas duct, due to the cleaning of time gases from ash (a requirement of the rules of technical operation of PTE).

Features of antibodies against benzo[a]pyrene formation in workers of coal mines and thermal power plants

2019 ◽  
pp. 9-14
Author(s):  
Ye. G. Polenok ◽  
S. A. Mun ◽  
L. A. Gordeeva ◽  
A. A. Glushkov ◽  
M. V. Kostyanko ◽  
...  
Keyword(s):  
Power Plant ◽  
Thermal Power Plant ◽  
Power Plants ◽  
Reference Group ◽  
Coal Dust ◽  
Thermal Power ◽  
Coal Mines ◽  
Serum Levels ◽  
Thermal Power Plants ◽  
Immune Reactions

Introduction.Coal dust and coal fi ring products contain large amounts of carcinogenic chemicals (specifically benz[a]pyrene) that are different in influence on workers of coal mines and thermal power plants. Specific immune reactions to benz[a]pyrene therefore in these categories of workers can have specific features.Objective.To reveal features of antibodies specifi c to benz[a]pyrene formation in workers of coal mines and thermal power plants.Materials and methods.The study covered A and G class antibodies against benz[a]pyrene (IgA-Bp and IgG-Bp) in serum of 705 males: 213 donors of Kemerovo blood transfusion center (group 1, reference); 293 miners(group 2) and 199 thermal power plant workers (group 3). Benz[a]pyrene conjugate with bovine serum albumin as an adsorbed antigen was subjected to immune-enzyme assay.Results.IgA-Bp levels in the miners (Me = 2.7) did not differ from those in the reference group (Me = 2.9), but in the thermal power plant workers (Me = 3.7) were reliably higher than those in healthy men and in the miners (p<0.0001). Levels of IgG-Bp in the miners (Me = 5.0) appeared to be lower than those in the reference group (Me = 6.4; (p = 0.05). IgG-Bb level in the thermal power plantworkers (Me = 7.4) exceeded the parameters in the healthy donors and the miners (p<0.0001). Non-industrial factors (age and smoking) appeared tohave no influence on specific immune reactions against benz[a]pyrene in the miners and the thermal power plant workers.Conclusions.Specific immune reactions against benz[a]pyrene in the miners and the thermal power plant workers are characterized by peculiarities: the miners demonstrate lower levels of class A serum antibodies to benz[a]pyrene; the thermal power plant workers present increased serum levels of class G antibodies to benz[a]pyrene. These peculiarities result from only the occupational features, but do not depend on such factors as age, smoking and length of service at hazardous production. It is expedient to study specific immune reactions to benz[a]pyrene in workers of coal mines and thermal power plants, to evaluate individual oncologic risk and if malignancies occur.

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 Improving the reliability, as well as energy and environmental efficiency of gas cleaning systems at TPP

2019 ◽  
Vol 11 (4) ◽  
pp. 288-293 ◽  
Author(s):  
A. T. Zamalieva ◽  
M. G. Ziganshin
Keyword(s):  
Power Plants ◽  
Stokes Equations ◽  
Coal Dust ◽  
Thermal Power ◽  
Primary Energy ◽  
Navier Stokes ◽  
Thermal Power Plants ◽  
Industrial Emissions ◽  
Gas Treatment ◽  
Gas Cleaning

Energy is the basic sector of the economy and the largest consumer of primary energy resources of any country, which is why the development of world energy is accompanied by global pressure on the environment. The issues are considered of reducing the atmospheric impact of emissions of thermal power plants, improving the reliability and working life of their units, systems, and plants as a whole. The principles are presented of development and improvement of technologies for processing industrial emissions of thermal power plants, the neutralization of which is currently relevant on a regional and global scale. Analysis is carried out of existing methods of cyclone and filtration treatment. An improved design of a cyclone filter is proposed, which allows to increase the reliability of gas turbine and steam-gas units of TPP, while ensuring the efficiency of separation of the suspended part of the flow at the gas treatment point (GTP) of TPP. Similar devices can also be used to increase the degree of cleaning atmospheric emissions released by the TPP coal dust preparation and flue gas systems at coal generation from fi ne particles of PM10 and PM2,5 classes (coal dust and ash), owing to reduction of the size of caught particles from average values for cyclones and wet scrubbers of the order of 5–10 μm to 0.5 μm. The design of the cyclone filter is improved as a result of research of cyclone filtration by methods of Computational Fluid Dynamics (CFD). A system of Reynolds-averaged equations of a single-phase Navier-Stokes flow is used for mathematical modeling of motion in the cyclone filter. To determine the efficiency of separation of the suspended part of the flow in the cyclone filter, the Rercomplex is used obtained by reducing a set comprising the Navier-Stokes equations and the equation of particle motion based on Newton's law to a dimensionless form. Numerical characteristics of the suspension sedimentation from a multiphase flow in a cyclone separator of specified dimensions are found by means of the Rercomplex. The results of bench tests of the proposed design of the cyclone filter are given. 

scholarly journals The issue of improving the efficiency of nitrogen oxide neutralization systems in diesel internal combustion engines

2021 ◽  
Vol 1 (2) ◽  
pp. 101-112
Author(s):  
A.V. Shabanov ◽  
◽  
D.V. Kondratiev ◽  
V.K. Vanin ◽  
A.Yu. Dunin ◽  
...  
Keyword(s):  
Nitrogen Oxides ◽  
Internal Combustion Engine ◽  
Power Plants ◽  
Internal Combustion Engines ◽  
High Efficiency ◽  
Combustion Engine ◽  
Thermal Power ◽  
Internal Combustion ◽  
Urea Solution ◽  
Exhaust Gas

The most effective method of reducing nitrogen oxides in diesel exhaust gas is selective purifica-tion by the SCR-NH3 method. The method uses ammonia released during thermolysis and hydroly-sis of a urea solution when it is injected through a nozzle into a neutralizer. This method has a rela-tively low efficiency of cleaning the exhaust gas from nitrogen oxides. The main factor hindering the achievement of high efficiency of the NOx neutralization system is the insufficiently high tem-perature during the implementation of this process. The article analyzes various ways to increase the efficiency of the neutralization process and proposes a new method for neutralizing NOx by using urea injection into the cylinders of the inter-nal combustion engine at the expansion stroke in a diesel internal combustion engine. Efficiency can be achieved due to a higher exhaust gas temperature in the cylinder of the internal combustion engine and an increase in the time of the process of thermolysis and hydrolysis of urea. The kinetics of the decomposition of nitrogen oxides, the process of NH3 oxidation, and the cal-culation of temperature conditions in the cylinder of a diesel internal combustion engine at the ex-haust cycle are considered. The experience of neutralization of NOx contained in the flue gases of thermal power plants, where NOx purification takes place at high temperatures without the use of a catalyst, is analyzed. It is shown that the modernization of the SCR-NH3 process, due to the injection of urea at the exhaust stroke in a diesel internal combustion engine, will simplify the existing method of NOx neutralization and at the same time obtain additional advantages for a modern high-speed engine

scholarly journals CORRELATION ANALYSIS OF SATELLITE DATA ON CARBON DIOXIDE EMISSIONS AND VEGETATION INDEXES IN THE TERRITORY OF DONBASS

2020 ◽  
Vol 2 (5) ◽  
pp. 104-110
Author(s):  
F.V. Nedopekin ◽  
◽  
N.S. Shestavin ◽  
V.V. Yurchenko ◽  
◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Satellite Data ◽  
Carbon Dioxide Emissions ◽  
Power Plants ◽  
Near Infrared ◽  
Thermal Power ◽  
Anthropogenic Sources ◽  
The Black Sea ◽  
Control Points ◽  
Vegetation Indexes

Using the Emissions Database for Global Atmospheric Research satellite data on the annual global carbon dioxide emissions, their distributions in the Donbass were obtained for the period from 2013 to 2018, indicating their main anthropogenic sources: large cities, thermal power plants and metallurgical plants. Control points were selected near and far from the largest sources of carbon dioxide emissions and, with the help of the resources of the Shared Use Center, systems for archiving, processing and analysis of satellite data of the Institute of Space Research of the Russian Academy of Sciences, the average annual vegetation indexes in the territory of Donbass and at control points for the same period of time were determined. A comparison was made of the reflection intensities in the near infrared and red regions of the spectrum, as well as the normalized relative vegetation indexes at these control points. It is indicated that there is no direct correlation between the values of vegetation indexes and the concentration of carbon dioxide in a given period of time. A sharp decrease in the volume of biomass was noted in a number of control points due to the appearance of signs of drought in the Black Sea region, as well as a significant increase in wild vegetation in the conflict zone in the eastern regions of Donbass.

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