Nitrogen Oxides NOx Research Articles

Seasonal persistence of the nitrogen oxides production in Mexico City

AbstractThis study investigates the seasonal influence on the nitrogen oxide NOx pollution records at four monitoring sites in Mexico City from 2010 to 2018. The analysis employs the second-order structure function to examine the trends in NOx concentration fluctuations. The findings reveal that the fluctuations follow a power law pattern characterized by Hurst exponents, predominantly in the statistical persistence regime, with a scaling range spanning three orders of magnitude. Specifically, the autumn period exhibits fluctuations with an exponent of $$\overline{H}=0.72$$ H ¯ = 0.72 , indicating relatively smaller fluctuations compared to other seasons, but with the potential for NOx concentrations to surpass those in other periods. In contrast, for spring, summer, and winter, the fluctuations are characterized by exponents of$$\overline{H}=0.59$$ H ¯ = 0.59 ,$$\overline{H}=0.61$$ H ¯ = 0.61 , and$$\overline{H}=0.62$$ H ¯ = 0.62 , respectively, demonstrating greater fluctuations with lower NOx concentrations compared to autumn. These results are consistent with various studies conducted worldwide. Additionally, a negative correlation between NOx and ozone (O3) has been established during the winter season, as NOx and O3 fluctuations display persistent and anti-persistent behavior, respectively.

Air pollution and grouping of cities according to their environmental status

In the article, the ecological situation of the cities located in the Kura-Araz plain is analyzed. Our study area is the most populated and most important agricultural region in the country. The possibility of environmental pollution is also high in the area located on the east- west roads. In particular, the pollutants released into the atmosphere were analyzed and the results were determined. During the research, the atmospheric pollution in the cities during the historical period was studied using the mathematical-statistical method. Ecological zoning of cities was carried out using GIS technologies. The main source of air pollution in cities is cars, their number, and the use of outdated cars. Another reason is the important industrial cities located in the study area. Substances released into the air from industrial enterprises pollute the atmosphere of the cities. It was determined that the environmental situation is more intense in cities where large industrial enterprises are located. There are large, medium and small cities in the study area. The main polluting cities are the cities of Mingachevir and Shirvan, which belong to the group of large and medium cities because the most important industrial enterprises of the country are located here. Also, these cities are important power centers of the country. These cities differ from others in terms of population. At the same time, we have included the city of Yevlakh in the group of cities with an important role in atmospheric pollution. As a result of the analysis, ecological zoning of cities was carried out. At this time, 3 gradations were used. During this zoning, the pollution of the atmosphere was taken into account. The influence of carbon monoxide CO2, carbon oxides CHx, nitrogen oxides NOx and sulfur oxides SOx on atmospheric air in cities was analyzed. The main cause of pollution is the location at the intersection of highways. The location on the east-west roads has made the ecological situation in the cities even more tense. Especially in Mingachevir and Shirvan, the environmental situation is more intense.

Nitrogen fixation and H2O2 production by an atmospheric pressure plasma jet operated in He–H20–N2–O2 gas mixtures

AbstractAtmospheric pressure plasmas are widely used for nitrogen fixation processes to produce ammonia NH3 or nitrogen oxides NOx, including, for example, nitrite NO2− or nitrate NO3−. Small‐scale atmospheric pressure plasma jets (APPJs) can provide the production of these species on demand at the site of consumption. The species of interest are generated by the plasma and can be dissolved in liquids, for example, to use them. In this work, liquid treatments were performed by an APPJ operated in a He––– gas composition to investigate the influence of the gas composition on the production of hydrogen peroxide , and . A validation of two diagnostics showed that the spectrophotometric approach using ammonium metavanadate was interfered by other species when was added to the system. Thus, electrochemical sensing of was performed. The concentrations of and were measured by commercially available test kits based on the o‐phythalaldehyde method and the Griess reagent, respectively. At low admixtures, the dominant species was with a maximum concentration of 0.9 mM, while became dominant at admixtures of 0.5% and higher with concentrations of up to 1.5 mM. was also present in the system and could be measured at low concentrations of less than 0.2 mM in the liquid. By varying the treatment distance and the gas flow rate, insights into the transport phenomena of the species and their dissolution into the liquid could be gained. Low‐frequency pulsing of the radio frequency (RF) jet led to an accumulating effect on , a reduced production of and a switch from ‐dominated production to ‐dominated production.

Thermal Power Plant Pollution Monitoring and Control using Internet of Things

In our day-to-day life, environmental degradation and global warming are essential factors to consider. These problems were caused due to the contamination of water, air, and soil with the waste generated by industries. The pollutants level generated by the industries to be measured and controlled by central and state pollution control board. The air pollutants are the major cause for the deterioration. The existing pollutant monitoring system are complicated, inaccurate, unreliable, delayed intimation and less efficient. Hence in mettur thermal power plant, the internet of things-based pollutant gas monitoring system has been implemented. This system consists of numerous gas sensors, Arduino UNO controller, ESP8266 Wi-Fi module, ubidots server and alarm. The pollutants measured are carbon monoxide (CO), suspended particulate matters (SPM), sulphur oxides (Sox), nitrogen oxides (Nox) in air. When the pollutants level of industry is crossed the limit, the pollution control board has been intimated the exact location of the industry through internet. The pollution control board can automatically send alert SMS and email to the respective industry. This system is suitable for the recent technology industrial internet of things. The electrostatic precipitator has been installed for pollutant control. It is proved that the proposed system is a very good replacement for the conventional monitoring system done by the human. It is acted as user friendly interface for the operation of the system and is reliable. The system has attained improved pollutant control, increased stability, and consistency of the power plant and finally the safety of the employees working in the power plants and mine areas.

Problems and prospects of creating modern agricultural gas diesel engines: A literature review

In conditions of constant growth in the cost of traditional oil products and their shortage, the issue of using alternative fuels becomes urgent. The purpose of the article is to identify ways of using alternative types of fuel for the operation of diesel engines. Research methods – analysis and verification of data obtained from scientific publications, which are part of the world-famous scient metric databases, for the relevance of the subject of research. The research results reveal the advantages and disadvantages of dual-fuel engines operating on gaseous fuel with diesel fuel additive, the impact of this type of engine on emissions and toxicity of exhaust gases, in particular nitrogen oxides NOx. The application of the so-called gas nozzle and the cross-section of the holes of its nozzles are substantiated. It was analysed and established that the most economically expedient is the use of liquefied petroleum gas for the operation of diesel engines by implementing the gas-liquid cycle; it was found that the most promising for this is gas cylinder equipment of the so-called 4th generation. A retrospective analysis of studies of internal combustion engines with gas cylinder equipment showed an increase in motor resource when using gaseous fuels, as well as the negative side of using gaseous fuels, which consists in reduced power when converting carburettor engines, however, the use of these fuels for the operation of diesel engines completely eliminates this disadvantage. Based on the research analysis, the influence of the ignition dose, when the engine is operating on the gas-diesel cycle, on the performance at different loads was also established, and a recommendation was found to switch to the diesel cycle from the gas-diesel cycle at loads less than 30% of the nominal one. The optimal scheme for the implementation of the gas-diesel cycle, which is relevant and promising for more widespread energy and transport vehicles, has been substantiated and selected. Based on the analysed schemes, it was established that the scheme that can be taken as a basis for further research in this direction is the scheme of the DG-Flex BOSCH gas-diesel system. The practical value of the work lies in the justification of complex conversion with partial replacement of diesel fuel with liquefied petroleum gas as the most rational way of converting serial diesel engines into dual-fuel engines

Reducing the Harmful Exhaust Emissions from the Diesel Engine of the Tractor CASE JX75T by using the EFWP Filter at Different Engine Speeds

In this investigation, the influence of using the EFWP filter on the tractor exhaust emissions was determined. A Water and paper filter is a filter designed to operate as a filter for the exhaust for the reduction of the harmful gas (CO, CO2, NOx, and HC) emission from the engine of the tractor. Emissions experiments were carried out on CASE JX75T tractor at different engine speeds are 750, 1000, 1250, 1500, 1750, 2000, and 2250 rpm. All engine speed of the tractor underwent experimentation before the installation of the EFWP filter and after installation it. The noises and Bsfec also were measured when the two cases. Each engine speed was tested for approximately 20 minutes in two cases. The results showed a significant (P≤0.05) decreasing in carbon monoxide CO (51.40%), carbon dioxide CO2 (25%), nitrogen oxides NOx (43.43%) and hydrocarbons HC (60.98%) emissions and also, the noises reduced by 25.38% and there was no significant increase in the BSFC (5.34% only) after the EFWP filter was put in the tractor exhaust. The results also showed that increasing the engine speed from 750 to 2250 rpm led to significant increases in CO2, NOx, and HC emissions, while decreased the CO emission. Also, the increased by a percentage of 155.88 and 159.38 % in the case using the EFWP filter and without using it (the ordinary case) respectively. Using the EFWP filter reduced the noises not overridden internationally permitted standards (65 dB).

222Rn and its relation with meteorological conditions and gaseous pollutants in the outdoor environment of Qena City South of Egypt

In the outdoor environment of Qena city, located in southern Egypt, 222Rn concentrations were continuously measured from January 2015 to December 2015 using Alpha-Guard radon monitor, PQ 2000 PRO. Meteorological parameters (air temperature AT, relative humidity RH, and evaporation rate EV) and gaseous pollutants [ozone O3, nitrogen oxide NOx, and particulate matter that has a diameter of less than 10 µm (PM10)] data for the same period were collected from the meteorological station. This work aims to study the potential relationships between 222Rn and each of the meteorological parameters and gaseous pollutants. According to observational data, the yearly average concentrations of 222Rn were 19.35 ± 1.58 Bq/m3, 31.68 ± 1.97 µg/m3 for O3, 9.97 ± 2.27 µg/m3 for NOx, and 109.95 ± 6.48 µg/m3 for PM10. The concentration of 222Rn is positively correlated with relative humidity, nitrogen oxide, and particulate matter, whereas it is negatively correlated with air temperature, evaporation rate, and ozone. Descriptive statistical analysis revealed various distribution patterns for 222Rn, meteorological parameters, and gaseous pollutants.

Study of Air Pollution by NOx from Petrol Fuels at Four Stations in Dakar–Senegal by Determining Nitrogen Content

NOX emissions are a health hazard, and are increasingly regulated in cars. NOx also contributes to the formation of acid rain and the eutrophication of ecosystems. Nitrogen oxides are a family of molecules including nitrogen monoxide (NO) and nitrogen dioxide (NO2). These gases are formed in the engine during high-temperature fuel combustion, and play a role in the formation of fine particles in ambient air. In this article, the aim is to determine the nitrogen content of gasoline samples taken at four gasoline stations of the most representative groups in terms of distribution of light petroleum products in order to assess the environmental impact due to greenhouse gas emissions resulting from the use of gasoline by vehicles and to reduce the nitrogen content in the form of nitrogen oxides NOx. After an introduction, we presented the material and the method used, followed by the results of our analyses and a discussion of the results obtained before concluding.

Towards Cleaner Cities: An Analysis of the Impact of Bus Fleet Decomposition on PM and NOX Emissions Reduction in Sustainable Public Transport

The problem of poor air quality in urban areas has a negative impact on the health of residents. This is especially important during periods of smog. In Poland, as in other countries, the problem of poor air quality, especially during the winter season, is associated with a high concentration of particulate pollutants in ambient air (PM10, PM2.5). Sources of particulate emissions, in addition to solid-fuel boilers, include means of transportation, especially those equipped with diesel engines. In turn, during periods of strong sunshine (spring and summer), the problem of photochemical smog, whose precursors are nitrogen oxides NOX, arises in urban areas. Their main sources of emissions are internal combustion engines. Therefore, to improve air quality in urban areas, changes are being made in the transport sector, among which is upgrading the fleet of urban transport vehicles to low- or zero-emission vehicles, which are more environmentally friendly. In addition, measures that reduce the harmfulness of the transportation sector to air quality include the introduction of clean transportation zones, as well as park-and-ride (P&R) systems. The purpose of this article is to present the results in terms of PM10, PM2.5, and NOx emission reductions, implemented over a period of two years (2021–2022) in the area of the Rzeszow agglomeration, related to the modernization of the suburban bus fleet and the implementation of a P&R system for passenger cars. The results of the study were compared with the value of estimated emissions from coal-fired boilers used for residential heating and hot water, which also contribute to smog. Thanks to the implementation of the project, i.e., the replacement of 52 old buses with new buses of the Euro VI emission class and the construction of new P&R spaces, the total average annual reduction in emissions amounted to approximately 703.6 kg of PM10, approximately 692.7 kg of PM2.5, and a reduction of approximately 10.4 tons of NOX.

ПРО ЗАКОРДОННИЙ ДОСВІД ЗАСТОСУВАННЯ БЕНЗИНОВИХ СУМІШЕЙ ІЗ СЕРЕДНІМ ТА ВИСОКИМ УМІСТОМ ЕТАНОЛУ ЯК АВТОМОБІЛЬНОГО ПАЛЬНОГО (ОГЛЯД)

A retrospective look at the use of alcohol fuel for the propulsion of automotive machinery with internal combustion engines allows us to talk about a rather long world practice in this area. However, a serious interest in etha-nol as a motor fuel began to rise after the world oil crisis of 1973 and especially within the later decades. The field of application of ethanol in road transport is largely determined by its physical and chemical properties, many of which are broadly knowт; but even experts are less acquainted with some others. Recently, there has been a growing interest in the use of gasoline blends with medium and high ethanol content for motor vehicles, which has caused the need for serious research in this area. In particular, research and testing works are required to determine the influence of ethanol-gasoline blends use on motor vehicle systems and component’s durability, as well as environmental impacе of such fuels broad application. Overall, from the viewpoint of the practice on operating internal combustion engines and motor vehi-cles in general, which may be at least a temporary solution in the strategic development of road transport, the use of gasoline with rather high ethanol content may have its drawbacks. Therefore, in this article it is considered some pro-spects and problems in large-scale usage of motor fuel with medium and high ethanol content in a number of world countries. The regulatory and scientific-and-technological preconditions for the use of such automotive fuel are dis-cussed. Some results of research and tesings in a number of countries regarding the impact of using fuel with medium and high ethanol content on the durability of engines/wheeled vehicles and on the ambient air are also presented. The conclusion is that not only laboratory research, but more comprehensive road testing is required to define the real op-portunities and challenges in this area. Keywords: ethanol, gasoline blends, wheeled vehicle, internal combustion engine. hydrocarbons (HC), carbon monoxide (CO); nitrogen oxides (Nox); particulate matters (PM); thre-way catalytic converter; durability of vehicle’s components.

Particulate Matter and Gaseous Emissions from Yagya Fume in Open and Closed Door Environment

The practice of Yagya, a traditional Vedic ritual involving the combustion of specific materials, has significant therapeutic potential through its fume. We examined the Yagya fume for particulate matter (PM) and various gas levels. In the open-room environment (n= 40) PM1, PM2.5, and PM10 levels exceeded 1000 µg/m3. However, these levels returned to the baseline of 250 µg/m3 just after the Yagya. Carbon dioxide remained consistent, with median concentrations of 2000 ppm with or without Yagya. Carbon monoxide (CO) levels increased to 20 ppm during the Yagya but remained at 0.4 ppm after the Yagya, like normal air conditions. In the closed-room environment (n= 3), immediate increases in PM levels above 1000 µg/m3 were observed, which gradually decreased to 250 µg/m3 after around 15 hours of Yagya. CO2 and CO levels initially rose and decreased to normal levels after 6 to 7 hours. Nitrogen oxides NOx and Ozone exhibited slight increases during Yagya, while Sulfur Dioxide SO2 levels remained unchanged. We suggest that the high PM levels during Yagya are unique to the source, viz., medicinal wood, Ghee, and Hawan samagri (herbal mixture), necessitating further investigation.

MODERN TECHNOLOGIES FOR INCREASING THE ENERGY AND ENVIRONMENTAL EFFICIENCY OF ENERGY PRODUCTION

The problems of energy efficiency of energy production along with improving the environmental safety of enterprises are becoming increasingly relevant. One of the ways to solve these problems is the implemention of effective technologies, which include microflare incineration technology (MIT-technology) of gaseous fuels. The use of MIT- technology, in addition to a significant reduction in harmful emissions into the atmosphere, can simultaneously increase the energy efficiency of thermal power plants.
 A significant positive effect can also be achieved by using contact energy exchange plants. A striking example of such a gas-steam plant “Aquarius” the operation of which exceeds the efficiency of gas turbine plants by 10-12% with a simultaneous significant decrease in the concentration of toxic nitrogen oxides NOx and carbon monoxide CO in flue gases.

The Effect of Flue Gas Recirculation on CO, PM and NOx Emissions in Pellet Stove Combustion

Pellet stoves are popular appliances because they are an affordable technology and because the fuel is easy to store and to use. The increasing concern for environmental issues, however, requires a continuous effort to reduce pollutant levels in the atmosphere. This experimental work focuses on flue gas recirculation (FGR) as a possible way to improve combustion and decrease the emissions of carbon monoxide CO, particulate matter PM, and nitrogen oxides NOx in order to fulfill European and Italian emission requirements, for NOx in particular. A pellet stove has been tested in several experimental sessions with and without FGR. Pollutant emissions have been measured and analyzed in terms of statistical summaries and instantaneous trends. With FGR, the average CO and PM emissions were found to be 80% and 45% lower than the corresponding emissions without FGR. Results for PM are significant since FGR reduces emissions well below the most restrictive limits enforced in Italy. The analysis of instantaneous emissions in relation to excess air indicated that FGR can considerably reduce emissions, especially at the extremities of the oxygen O2 content range. Optimal ranges of excess air, in terms of O2 in flue gas, were identified for both the tested configurations, in which CO and PM emissions are minimized. The optimal range is 8–9% without FGR, and it decreases to 5–7% with FGR. Finally, a reduction in NOx emissions by about 11% has been observed in the configuration with FGR. Although this reduction seems modest as compared to CO and PM, it is important in that it lowers the emission level to the most severe limit in Italian regulations and indicates an improved FGR system as the solution for further reduction.

Effect of the Main Operating Variables on Efficiency of Treating Industrial Flue Gases Using Potash and Yellow Phosphorus

One of the main environmental threats is the gases from industrial process or other emissions activities, albeit they are several, all concern directed toward Nitrogen oxides NOX and Sulfur oxides SOX; because they may be a hazard for human and environment. The separation of nitrogen and sulfur oxides from waste gases is found to be affected by several operating parameters, this paper discusses some of them. The experiments were done on a bench-scale; 2900 ppm and 550 ppm , and using, (10) g , (0.5) g yellow phosphorus () at , with vigorous stirring for removal. The removal efficiency is monitored for different values of the emulsion temperature, yellow phosphorus () weight, and the emulsion stirring intensity. The removal efficiency isproportional to the emulsion’s temperature in the range ( 45 OC to 65 OC).The optimum temperature was, Nevertheless, the results revealed the removal efficiency is proportional to the phosphorus weight, that the efficiency of removal increases as the P4 content increases. Increasing stirring intensity will directly increase the removal percentage and the optimum stirring intensity is 1734 rpm.

Nano-gold decorated ZnO: An alternative photocatalyst promising for NOx degradation

This study compares the (nitrogen oxides) NOx photocatalytic degradation performance of the commercial bare semiconductors, titanium dioxide (TiO2 P25) and zinc oxide (ZnO), with that of the homemade gold (Au)-decorated semiconductors, Au/TiO2 and Au/ZnO (1 wt% Au). A plasmonic absorption band was observed at 550 nm for Au/TiO2 and around 700 nm for Au/ZnO. Aqueous dispersions based on these oxides were sprayed on mortar surfaces. The results revealed that Au/ZnO had a high NO degradation capability, comparable to that of TiO2 P25, and the best selectivity towards the formation of nitrates instead of NO2. The Au decoration clearly improved the photocatalytic response of ZnO, notably by avoiding the production of NO2. This positive effect was attributed to the better charge carrier separation and higher OH• production induced by the presence of Au. To the best of our knowledge, this was the first study on Au/ZnO used for NO photocatalytic degradation.

ВИЗНАЧЕННЯ ЗОВНІШНІХ ШВИДКІСНИХ ХАРАКТЕРИСТИК СИЛОВОГО ОБЛАДНАННЯ ДОРОЖНІХ МАШИН

The paper deals with the issue of determining the fuel efficiency and toxicity of exhaust gases of power equipment of road machines operating in traction modes, namely, plow and plow-brush snowplows based on a pneumatic wheeled tractor. The object of research is fuel efficiency and toxicity of exhaust gases of power equipment. The purpose of the study is to experimentally determine the external speed characteristics of a 4Ч11,0 / 12,5 diesel engine (D-240, D-241, D-242, D-243 families), namely: maximum power Ne, maximum torque Mк; hourly consumption of fuel Gпал and air Gпов, specific effective fuel consumption ge; concentrations of harmful substances in the exhaust gases: carbon monoxide CO, hydrocarbon compounds CmHn, nitrogen oxides NOx and opacity N of the exhaust gases. The paper presents the results of experimental studies to determine the energy performance (maximum power Ne and maximum torque Mк) of a diesel engine (4Ч11,0/12,5 (D-242)) of power equipment; fuel efficiency indicators (hourly fuel consumption Gпал and specific effective fuel consumption ge); hourly air consumption Gпов; concentrations of harmful substances in the exhaust gases: carbon monoxide CO, hydrocarbon compounds CmHn, nitrogen oxides NOx and opacity N of the exhaust gases. Which are obtained with the position of the fuel supply control, which corresponds to the maximum fuel supply from the diesel crankshaft speed. The above indicators were determined at standard diesel fuel supply settings. Based on the obtained external speed characteristics Ne, Mк, Gпал, ge, Gпов, CO, CmHn, NOx and N, mathematical (polynomial) dependencies were determined, which are described from the speed of the diesel crankshaft, and their adequacy was checked. The studies carried out made it possible to determine the main direction of increasing fuel efficiency and reducing emissions of harmful substances of a diesel engine.

IMPROVMENT OF ENVIRONMENTAL PERFORMANCE TWO-STROKE DIESEL DURING OPERATION

The development of world shipping is taking place in the context of ever-increasing requirements to reduce the concentrations of toxic components of gaseous combustion products of hydrocarbon fuels. Concentration limits for these substances are regulated in accordance with Appendix VI of the MARPOL 73/78 Convention. Among the controlled components of diesel exhaust gases, nitrogen oxides are the most dangerous for humans and environment. However, a decrease in the content of nitrogen oxides is inevitably associated with limitations on the maximum cycle temperature, that is, thermal efficiency, and hence with a deterioration in the fuel efficiency of the engine. At the moment, in order to reduce emissions of nitrogen oxides by large transport diesel engines, the most widely used is the recirculation of exhaust gases into the air receiver. A significant disadvantage of using this scheme is the need for cooling the exhaust gases and their additional purification, which leads to an increase in the weight and size characteristics of the system and to its rise in price. Therefore, to reduce its cost, it seems logical to combine exhaust gas recirculation with other ways to reduce nitrogen oxide emissions. For engines in operation, one of these methods is to change the angle of fuel injection. It can be assumed that the later the fuel is injected into the cylinder, the lower the temperature of the air charge will be and, accordingly, the lower the maximum combustion temperature, and hence the amount of nitrogen oxides. The calculation of nitrogen oxide emissions was simulated for the main engine MAN-B&W 7S50MC-C installed on the vessel "LILA SHANGHAI". Initially, the model created using the AVL-BOOST package was verified based on the available indexing results. After verification, the calculation of emissions of nitrogen oxides NOx was made with a variation in the angle of the start of fuel combustion at the nominal mode. The composition of the gases in the receiver was taken unchanged. As the fuel combustion start angle shifted further from the TDC, deterioration in fuel efficiency and a drop in cylinder power were observed, while reducing the mass of emitted nitrogen oxides NOx. However, it can be said that the environmental friendliness of an engine improves much faster than its fuel and power characteristics deteriorate. The above calculations show that for engines already in operation, changing the fuel injection angle makes it possible to reduce nitrogen oxide emissions. Therefore, this approach can be combined without much difficulty with other methods, thus reducing the cost of environmental improvement of the engine.

ENSURING THE ENVIRONMENTAL FRIENDLINESS OF MARINE DIESEL ENGINES OF SPECIALIZED SHIPS

Marine diesel engines (as the main component of a marine power plant) are sources of environmental pollution with exhaust gases, which include toxic components: carbon dioxide CO, hydrocarbons CnHm, soot C, sulfur oxides SOX, nitrogen oxides NOX [1-3]. Nitrogen oxides NOX occupy the first place among harmful emissions in almost all operating modes of diesel engines, regardless of their type, size and design features. Emission of nitrogen oxides with exhaust gases marine diesel engines is regulated by the requirements of Annex VI MARPOL. In accordance with the Tier-I, Tier-II, Tier-III standards (which apply to diesel engines of ships built after 2000, 2011 and 2016), the maximum amount of NOX in exhaust gases should not exceed the values determined by special expressions

Ignition and combustion characteristics of coal - water fuels based on coal & semi-coke

AnnotationThe article presents the results of experimental and theoretical studies of the ignition processes of coal- water fuel (CWF) drops made from coals of various degrees of metamorphism and coal semi-coke of these coals. It is shown that the preliminary torrefaction of coal leads to a significant improvement in environmental performance (50–60% reduction in flue gas concentrations of the main anthropogenic coal combustion products: nitrogen oxides NOx and sulfur SOx) of coal- water fuel combustion processes. This effect is most pronounced during the combustion of CWF based on lignite. Also, according to the results of the experiments, the ignition delay times of typical droplets (in the initial state), and then particles (after drying the near-surface fuel layer) of coal- water fuel s based on coals and coal semi-coke were established. It has been established that the ignition delay times of coal- water fuel particles based on pre-torrefied coals at relatively low ambient temperatures (Tg≤873 K) are on average 20% higher than when igniting CWF droplets based on natural coal. Under conditions of high-temperature heating, the ignition delay times of CWF particles made from natural coal and semi-coke differ insignificantly (no more than 2%).Based on the results of the experimental studies, a mathematical model of the ignition process of a coal- water fuel drop based on semi-coke was developed, which differs from the known ones in a relatively simple description of the most significant processes of thermal preparation and ignition, but at the same time retains a fairly high predictive potential. Using the previously developed method of quasi-stationary "thermal approximation" with the selection of an asymptotic estimate, an analytical solution is derived for the essentially nonlinear problem of coal- water fuel droplet ignition. ColloquiumAn analysis of modern political discourse shows that the information entropy associated with the problem of the anthropogenic impact of mankind on the planet's atmosphere as a result of the operation of energy facilities is constantly growing. At the same time, the constant growth of energy consumption in the world makes it necessary to introduce more and more new heat and power generating capacities. For a long time (the last 30 years) it was believed that the solution to all energy problems is the large-scale introduction of non-traditional renewable energy sources (solar batteries and wind power generators - RES) into the overall balance of energy generation. However, recent events in North America and Western Europe show that the potential for using renewable energy sources is significantly limited, and electricity generation from these renewable energy sources is still significantly unstable. In this regard, a new impetus for development is acquiring coal energy. However, the main problem of coal power engineering, the anthropogenic impact of thermal power plants on the planet's atmosphere, remains unresolved. This situation creates prerequisites for the development of new "clean" coal technologies with complete sequestration of anthropogenic emissions generated during coal combustion. This article presents the results of experimental and theoretical studies of the combustion processes of coal-water suspensions prepared from pre-torrefied coals. As a result of preliminary thermal (pyrolysis under conditions of high-temperature heating in an inert environment) preparation of coal, gaseous pyrolysis products are formed and removed into the external environment, a large proportion of which are hydrogen sulfide (the main source of sulfur oxides) and hydrocyanic acid (the main source of nitrogen oxides). After the preliminary pyrolysis of coal, a mixture of coke carbon and the mineral part of coal remains. When burning a coal-water suspension based on torrefied coal, only carbon dioxide and water vapor are formed. The latter can be relatively easily condensed and returned back to the power generation cycle (or disposed of). Accordingly, the combustion of CWF based on torrefied coal creates the prerequisites for the fundamental justification of the technology for environmentally friendly combustion of coal in the combustion chambers of gas turbine plants operating on the Allam cycle.

ESTIMATING STUDY FOR CALCULATING ELECTRICAL DIESEL GENERATORS EMISSIONS IN THE CENTER OF KUT CITY

Diesel generators which are used in the living quarters when electricity is cut off, is a significant source of emissions of polluted air.This paper presents an estimating study for emissions from electric diesel generators in the center of Kut city. This study includes statistics for the types of electric diesel generators, their power, fuel consumption and sites of these generators. Emissions are calculated by using modern methods which are used by U.S. Environmental Protection Agency and European Environmental Protection Agency, and also different sources of research. Two main methods are adopted in calculating the emissions; the first one considers the fuel consumption while the second considers the average rated power of these generators, load factor and operating hours. Calculations consider two seasons: winter and summer, also operating hours in the day and night are considered during summer.The estimating results show the emissions are nearly 25-68 ton from carbon monoxide CO, 189-515 ton from nitrogen oxides NOx, 10428-28335 ton from carbon dioxide CO2,8-21 ton from volatile organic compounds VOC,66-180 ton from sulfur oxides SOx and 23-64 ton from particulate matter PM.