Emissions Of Harmful Substances Research Articles

THE IMPACT OF LOW-CARBON DEVELOPMENT ON MUNICIPAL UTILITIES (SYSTEMIC APPROACH)

Due to the growing awareness of climate change and the serious threats it poses to the planet, more and more attention is being paid to the transition to low-carbon development in all spheres of human activity. Municipal management is an important industry that directly affects the environmental condition of cities and towns, as well as energy consumption and greenhouse gas emissions. Despite various measures and initiatives to improve the state of public utilities, there are serious problems that make it difficult to effectively transition to low-carbon development. High levels of pollution: Utilities such as thermal power plants, waste treatment plants, and water supply systems continue to use large amounts of hydrocarbon fuels and technologies that result in significant emissions of greenhouse gases and other harmful substances. Also, many cities lack the necessary infrastructure and technologies for efficient waste collection and processing, efficient energy saving, and the use of renewable energy sources. Regarding the provision of adequate financing, most municipalities face limited financial resources, which makes it difficult to implement the latest environmental technologies and programs. Lack of community awareness and involvement is also an important factor. Many residents of cities and towns do not have sufficient awareness of the importance of low-carbon development and its positive impact on the environment, which makes it difficult to make environmentally-oriented decisions and implement changes in consumer behavior. In light of these problems, there is a need to create and implement complex strategies and measures to optimize the activities of the utility industry, aimed at increasing efficiency, reducing greenhouse gas emissions, developing renewable energy, modernizing infrastructure, and involving the public in active participation in environmental programs and projects. However, it should be taken into account that each city or village has its own characteristics and requirements, therefore the optimization of communal services should be carried out individually, taking into account the specifics of the local situation. Keywords: utilities, systems approach, low-carbon development, sustainable development, systems analysis.

Study on Energy Efficient Operation by ship's Trim Optimization based on Computational Fluid Dynamics

The prediction and optimization on resistance characteristics of marine vessels are getting important due to maritime environmental pollution, climate changes, impacts on human health near the coastal area and so on. Therefore, several methods were developed to reduce the fuel consumption of the vessel to improve the voyage performance. Among them, the trim optimization method is one of the popular methods to reduce the fuel consumption of ships. Trim optimization can be done by changing the trim by moving the cargo or ballast water and also can be applied on both new and existing ships. Moreover, this method needs not to change any structural arrangement or machinery of the vessels to apply it. Therefore, in this paper, this method was evaluated by using computational fluid dynamics with the help of commercial software Star-CCM+. Firstly, the numerical analysis of resistance data for KRISO Container Ship (KCS) in even keel were carried out and compared with experimental data from the model test to validate the results. After that, the optimum trim values for different service speeds were estimated using the calculated resistances. It is found that trim optimization at various speeds can be an effective and convenient way for vessels to decrease fuel consumption, emission of harmful substances and improve the energy efficiency by reducing the total drag force. Therefore, it could be one of the most practical ways to improve the environmental friendliness for both new and existing ships and also to fulfill the environmental related regulations.

OPERATING MODES OF MICRO-HYDROELECTRIC POWER PLANT WITH OUTPUT VOLTAGE STABILIZATION USING INVERTER CONTROL

Link for citation: Lukutin B.B., Shandarova E.B., Popov M. M. Operating modes of micro-hydroelectric power plant with output voltage stabilization using inverter control. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 8, рр. 51-58. In Rus. The relevance. The use of Russia's hydroelectric potential for electricity generation is one of the cleanest and environmentally friendly methods as it does not result in the emission of harmful substances and carbon dioxide into the atmosphere. Moreover, it is a reliable and efficient source of energy as water is a constant source of energy. Hydro turbines are used to convert the energy of water flow into electrical energy, which effectively ensures more reliable and stable production capacity for hydroelectric installations. However, micro-hydroelectric power plants have some drawbacks related to difficulties in ensuring the high quality of produced electricity of autonomous power supply systems. This is due to the fact that the load on the autonomous power supply system can vary not only in magnitude but also in nature, which makes it difficult to maintain a stable level of electricity production. The main goal of the research is to determine the ranges of variation of the output electrical parameters of a non-regulated hydrogenerator operating as part of an inverter-based micro-hydroelectric power station for rural domestic consumers. Additionally, the task is to formulate requirements for the hydrogenerator and power conversion devices in static and dynamic operating modes of the autonomous power supply system. Object: inverter-based micro-hydroelectric power station. Methods: simulation modeling, and programming in Matlab Simulink. Results. A simulation model of an electric power supply system with an inverter microelectric power station was developed. The structure of microelectric power station is proposed, as well as the ranges of voltage changes of the microelectric power station generator are obtained.

INCREASING THE EFFICIENCY OF HEAT PUMP USING CIRCULATING WATER OF POWER PLANTS

In the article analytical studies of the efficiency of heat pumps in the thermal schemes of thermal and nuclear power plants for centralized heating and hot water supply systems taking into account the climatic conditions of Ukraine have been carried out. This task meets the objectives of energy saving and reduces emissions of harmful substances into the environment. The main focus is on improving the efficiency of the heat pump power supply system, which integrates an alternative energy source. An analysis of the exergy parameters of heat pump cycles has been performed, which have made it possible to establish that the most efficient working fluid of the cycle is freon R152a, at which the highest heat pump conversion coefficient and the lowest compressor power indicator are achieved. Ways and methods leading to reduction to underproduction of the electricity by turbine of of power plant and to increasation of the efficiency of a steam turbine cycle are proposed. It is shown that the efficiency of the system is most affected by losses in the evaporator, so the efficiency of this element of the heat pump should be given the most attention when using the energy of circulating water. An additional aspect of the novelty of the proposed method lies in the possibility of further optimization of the technical and economic parameters of the power system. A methodology based on the use of the exergy method of analysis to substantiate the conditions for the rational use of heat pumps for power plants in the utilization of low-grade heat of circulating water for cooling the turbine condensers is proposed, which can be considered as innovative way. Results open the further prospects for the development of heat pump heat supplyhas been proposed.

Carbon Capture and Storage through Upcycling of Suberinic Acid Residues in Wood Composites Finishing

Finishing coatings used in the wood-based composite industry play a key role in the final appearance of the finished product. However, the use of such coatings is not only for aesthetic purposes, but also to protect the product against surface damage and moisture or to minimize the emission of harmful substances. The latter is an extremely important factor in terms of safety for both the manufacturer and the user, which is why the emissivity test is one of the most important tests conducted in this case. Carbon-rich materials, such as those remaining from the extraction of birch bark, can fulfill the role of minimizing the emission of harmful substances. In this article, an attempt to create coatings in the form of a film by combining a biopolymer with suberinic acid residues (SARs) was made. Two types of biopolymers were used, polylactide (PLA) and polycaprolactone (PCL), in various polymer–SAR ratios. Suberinic acid as a residue is a raw material that can potentially contribute positively to the fixing of CO2 from the atmosphere, which creates the possibility for further use. As part of this study, the obtained coatings were tested in terms of scratch resistance, relative hardness, cold liquids, total volatile organic compounds (TVOCs), formaldehyde emission, surface absorption, etc. Differences between the polymers used and the effect of the SAR additive on selected surface properties were demonstrated. The addition of carbon-rich SAR significantly improves gas barrier properties of the PLA- and PCL-based surface finishing materials. The relative hardness and scratch resistance also increased with rising SAR content. However, the increasing content of SAR filler acts as a limiter in the depth of penetration of the deposited surface finishing materials onto the wood surface. It is possible to state that this innovative approach regarding (1) the utilization of biopolymers as a matrix, instead of conventional, crude oil-based resins, and (2) the incorporation of post-processed carbon-rich waste lignocellulosic materials to produce the surface finishing and/or protective films has been confirmed.

Research and Development of the Oxy-Fuel Combustion Power Cycle for the Combined Production of Electricity and Hydrogen

Modern trends in improving environmental safety have determined the urgency in creating innovative technologies that allow the production of electricity and hydrogen without the emission of harmful substances. However, at the moment, there are not so many technical solutions offering the combined production of these useful products with a high degree of efficiency and environmental friendliness. The transition to oxy-fuel combustion power cycles for the co-production of electricity and hydrogen is a prospective way to decrease carbon dioxide emissions into the atmosphere from the energy sector. To achieve zero emissions, the semi-closed oxy-fuel combustion cycle is combined with a steam methane reformer, which has a high energy efficiency through reducing losses in the steam turbine condenser. The modeling methodology has been described in detail, including the approaches to defining the working fluid properties and mathematical models of the different steam methane reforming plants and the oxy-fuel combustion power plant. According to the results of the thermodynamic analysis of the steam methane reforming plant, it was found that an increase in the temperature from 850 to 1000 °C leads to a decrease in the mass flow fuel by 16.3% due to the shift towards a direct reaction. Moreover, the optimal temperature in the reformer lies in the range of 900–950 °C. A comparison of the energetic and ecological characteristics of various steam methane reformer units showed that the scheme with oxy-fuel combustion is better compared to the scheme with CO2 capture by absorption in monoethanolamine; the efficiency is 6.9% higher and emissions of carbon dioxide are 22 times lower. According to the results of the thermodynamic analysis of a novel oxy-fuel combustion power cycle, it was found that its performance varied regarding the range of electricity production (123.6–370 MW) and hydrogen production (0–10.8 kg/s). The efficiency of the oxy-fuel combustion power cycle varies in the range of 47.2–70.1%. Based on the results of the operation regimes analysis, the energy complex performance map has been developed, allowing identification of the efficiency and working fluid massflow by net power and produced hydrogen massflow.

Analysis of the potential of electro-waste as a source of hydrogen to power low-emission vehicle powertrains

The decarbonisation of transport is one of the key aspects in the context of environmental protection. These emissions are particularly noticeable in highly urbanised areas, where the possibility of dispersal of harmful substances is much lower. A way to improve emission factors is the introduction of hydrogen vehicles. Burning hydrogen in engines significantly reduces emissions of harmful substances into the atmosphere compared to the combustion of conventional fuels used today. Hydrogen can be obtained by gasifying waste in a steam atmosphere. Electronic waste is a special type of waste characterised by a high degree of commingling, which makes it difficult to treat. The volume of this type of waste is increasing year on year. As a result of this process, we are able to obtain syngas. This gas, after separation processes, can be a source of hydrogen, an energy carrier that could prove crucial in low-carbon energy or transport applications. This paper presents the results of the gasification of electronic waste, the composition of the syngas obtained in the process and an assessment of the potential of this waste treatment technology to power means of transport.

The use of plasma technologies to optimize fuel combustion processes and reduce emissions of harmful substances

The latest information technologies and 3D computer modeling methods were used to introduce new technology of plasma fuel ignition and stabilization of combustion processes. Numerical studies of the physicochemical processes occurring during the combustion of pulverized coal fuel flows in areas of real geometry (combustion chambers of thermal power plants) have been carried out. The main regularities of the influence of thermochemical plasma activation of pulverized coal flows on the process of fuel combustion in the combustion chambers of Kazakhstan boilers have been established. The conducted studies of the systems of thermochemical plasma activation of pulverized coal flows have shown the possibility and efficiency of their application at real thermal power facilities. This makes possible to solve both: economic problems (reducing the consumption of fuel oil) and environmental problems (reducing harmful dust and gas emissions from the combustion of low-grade coal fuels from Kazakhstan deposits). This will optimize the processes that occur during the combustion of energy fuel, reduce emissions of harmful substances into the atmosphere (carbon oxides, nitrogen oxides), create and implement in the future a new way to produce "clean" energy.

The current state and possible prospects for using liquefied natural gas tank containers

One of the ways to reduce emissions of harmful substances into the environment is considered in the paper. This way is connected with the transition from liquid and solid hydrocarbon fuels to liquefied natural gas, which is one of the reasons for the increase in gas fuel consumption with the observed growth in the last decade for its transportation in liquefied form in tank containers. The main countries owning tank containers are the USA, Germany and the UK. It is noted that tank containers are used for transportation and storage of liquefied gas in small volumes for end users; this method of transportation is mobile, since sea, rail and automobile transport can be used for this; storage of liquefied gas in tank containers does not require the construction of additional infrastructure. Further prospects of tank containers for liquefied natural gas are considered. The possibility of supplying gas by tank containers, especially for autonomous remote settlements and regions of the Russian Federation with a low population density, while in these regions the population needs gas for heating residential buildings, is discussed. The use of tank containers, due to its advantages, may have the potential for use in the Russian Federation. Thus, within the framework of the review study, the issues of the current state and prospects for the use of tank containers for LNG transportation are considered in detail. It is noted that the mobility and flexibility of transportation ensures storage without additional refrigeration systems for about three months, including that LNG tank containers are used for gas supply to sparsely populated and hard-to-reach points without connection to main gas pipelines, satisfaction of short-term peak gas consumption in winter, and use of gas as motor fuel for the various types of transport.

TEHNOLOŠKI NAPREDAK I KLIMATSKE PROMJENE – TEMA U OBRAZOVANJU INŽENJERA / TECHNOLOGICAL PROGRESS AND CLIMATE CHANGE – TOPIC IN ENGINEERING EDUCATION

At the beginning of the 21st century, environmental issues became leaders in all areas of human activity without competition. All other essential topics: health, food, energy, water, and air, are predominantly determined by environmental problems. Climate change is a result of excessive CO2 emissions due to the greenhouse effect, air pollution as a result of emissions of harmful substances by thermal power plants, chemical plants, heating boilers, individual furnaces, means of transport; pollution of drinking water, pollution and devastation of arable land, destruction of forests, pollution of rivers due to inadequate wastewater treatment, etc. are problems that require a radical change in man's attitude towards the environment, which leads to the need to reconsider and change the current way of doing business. The paper analyzes the impact of scientific achievements in electrical engineering on the accelerated industrial growth that has led to today's environmental problems. Industrial development is explored in phases (Industry 1.0, Industry 2.0, Industry 3.0, Industry 4.0) regarding the impact of radical changes in doing business. Since we are now in phase 4, the dominant topics are energy transition, energy efficiency, renewable energy sources, recycling, innovation, electric vehicles, networking, Internet of Things (IoT), artificial intelligence, and 5G. Although all the above topics are multidisciplinary, a significant share of electrical engineering is clear. Existing plans and programs in electrical engineering, whether based on the traditional model of education or in the process of innovation, are adapted to new technological trends. As a rule, little or no importance is attached to environmental issues. As one of the answers to the mentioned problem at the Faculty of Electrical Engineering, University of Sarajevo, a new course, “Sustainable Development” was included. The paper briefly describes the content of this course.

PRODUCTION ENVIRONMENTALLY FRIENDLY DIESEL FUEL BASED ON DEAROMATIZED DIESEL FRACTION AND BUTYL ESTERS OF FATTY ACIDS OF SUNFLOWER OIL

Currently, special attention is paid to the environmental performance of fuels, because, the ever-increasing quantity of transport leads to an increase in the emission of harmful substances into the atmosphere. In particular, for the introduction of environmentally friendly technologies for the production of diesel fuels, first of all, it is necessary to obtain diesel fuel with a low content of sulfur, nitrogen and polycyclic aromatic compounds, which requires the processes of hydrotreating, hydrocracking and hydrodearomatization are carried out, which require significant economic costs. The presented article considers an alternative process for reducing the content of harmful substances, in particular aromatic compounds in the composition of diesel fuel. The process of dearomatization of the diesel fraction was carried out using N-methylpyrrolidone as an extractant at a ratio of extractant : diesel fraction 2:1 for 6 hours. The physicochemical properties of the dearomatized diesel fraction have been studied. In the resulting dearomatized diesel fraction, the sulfur content decreased to 0.0220%, and the content of aromatic compounds to 0%, in addition, the fractional composition is facilitated, the density and viscosity decrease. In order to replenish the resource of diesel fuel, oxygen-containing additives were added to the dearomatized diesel fraction - butyl esters of fatty acids of sunflower oil in an quantity of 5-10%, and the physicochemical properties of the resulting compounds were studied. It was revealed that the addition of butyl esters of fatty acids of sunflower oil to the composition of the dearomatized diesel fraction favorably affects the quality indicators of the obtained compounds. So, there is an increase in the flash point by 6°C and the cetane number by 4-5 points, and the sulfur content decreases to 0.0198%. In addition, the diameter of the wear scar decreases by about 2 times and for a 5% compound it is 0.430 mm, and for a 10% compound it is 0.370 mm, which meets the modern requirements of the standard. Thus, obtaining environmentally friendly diesel fuel is possible by dearomatization of the diesel fraction with the subsequent addition of butyl esters of fatty acids of sunflower oil, which can be recommended as a multifunctional additive to diesel fuels.

ANALYSIS OF THE EFFECTIVENESS OF LABOR PROTECTION MEASURES (ON THE EXAMPLE OF THE AULSKY VODOVID UTILITY COMPANY)

Actions to improve working conditions, systematic monitoring of the level of harmful and dangerous factors of the working environment, assistance in reducing occupational injuries and occupational morbidity are accompanied not only by social but also by economic effect. The economic efficiency of the measures carried out depends on the ratio of improvement of working conditions (estimated in monetary terms) and the amount of expenses of the enterprise for labor protection. As a result, the period of professional activity of workers increases, labor productivity increases, costs associated with occupational injuries and occupational morbidity are reduced, expenditures on benefits and compensations are reduced. In some industries, some progress can be made in reducing morbidity by reducing the impact of harmful factors of production on workers in the workplace, for example, by limiting emissions of harmful substances or using personal protective equipment.

Modernization of the Taxation System for Harmful Substances Emissions Caused by Vehicles

"This article aims at identifying the main tendencies in changing the taxation process of vehicle owners concerning harmful emissions produced by vehicles. Theoretical framework: According to the statistical data of international ecological companies, the EU countries have to reduce emissions from transport by 90% by 2050. Accordingly, by this period, the EU countries plan to increase the use of zero-emission vehicles significantly. Just a few decades ago, no fiscal instruments were in place to force consumers to pay attention to the environmental friendliness of cars. When conducting the research, the authors used the analytical and bibliographic method to study the scientific literature on vehicle owners’ taxation regarding harmful substances emissions, as well as induction, deduction, analysis, information synthesis, systemic and structural, comparative, logical and linguistic methods, abstraction, idealization for data study and processing, and a questionnaire survey conducted by the authors of the study online to practically clarify the most critical issues related to the taxation of harmful substances emissions caused by vehicles. Today, EU countries have a variety of tax methods that influence consumer behavior when choosing a vehicle based on its environmental friendliness, as it causes a quarter of all EU emissions. More than 70 % of these are generated by cars. For this reason, it is now time to reform the vehicle taxation system, taking into account the emission level they produce. The research results identified the leading, most important theoretical aspects of the vehicle owners’ taxation issue related to harmful emissions. Also, the authors studied the opinion of scientists and executives of regional bodies of the State Tax Service on the critical aspects of this issue. Road, rail, and water transport remain the top environmental pollutants today."

Assessment of the state of the ecosystem of the Lipetsk region

The characteristics of the state of the ecosystem of the Lipetsk Region are presented on the basis of official statistical reporting by the Office of Rospotrebnadzor for the Lipetsk Region, the Lipetsk Center for Hydrometeorology and Environmental Monitoring - a branch of the Central Chernozem UGMS, the Department of Ecology and Natural Resources of the Lipetsk Region. Environmental problems of the Lipetsk region are associated with pollution of atmospheric air,drinking water, soil, and food products by toxic substances. Sources of environmental pollution are ferrous metallurgy, chemical industry, motor vehicles, agricultural production, including livestock. Anthropogenic anomalies of the habitat are becoming one of the main causes of veterinary problems in modern animal husbandry. The purpose of the study: to assess the state of the ecosystem of the territory of the Lipetsk region, including monitoring of surface watercourses in the area of the city of Lipetsk: the rivers Matyra, Voronezh, Lipovka and the Matyr reservoir. For the analysis of water sources for heavy metal contamination with an atomic absorption spectrometer with electrothermal authorization "MGA-1000". Sampling of natural water was carried out according to GOST 17.1.5.05-85. The volume of the sample taken was 250 ml, the filtrate was preserved with nitric acid. Statistical processing of analytical data was carried out by conventional methods.Up to 90% of emissions of harmful substances from stationary and mobile sources of pollution are accumulated by soil, from where toxins migrate into water and plants. The content of zinc slightly exceeded the maximum permissible level in 35% of the selected samples, %, manganese - in 32% and aluminum - in 34% of the selected samples. So the highest content of iron and lead was recorded in the river. Voronezh and in the region of Lipetsk, exceeding the MPC by 1.5 times. To a lesser extent, increases in MPC r. Matyr and Matyr-sky reservoir.

Natural gas as an alternative to liquid hydrocarbons on diesel-powered vessels

Alternative fuels are increasingly being used in internal combustion engines (ICE) for various purposes. The practice of using alternative fuels indicates that their physicochemical properties make significant adjustments to the way the internal combustion engine workflow is organized and have a very significant impact on the effective and environmental performance of the engine and the entire power plant as a whole. The main task of designing a power plant with an internal combustion engine running on synthesis gas is to provide the necessary power, minimum fuel consumption in various operating modes, as well as minimum emissions of harmful substances into the environment, depending on the composition of the synthesis gas. It should be noted that the specific heat of combustion of synthesis gas is lower compared to traditional grades of fuel (25...30 MJ/kg), this leads to a significant reduction in the power of the marine engine. It is this factor that determines the use of synthesis gas as an additive to traditional fuel. Analysis of the available results and modeling of the combustion processes of liquefied natural gas on ships will allow to predict and determine further ways to improve fuel efficiency, power indicators and ecology of engines running on ethanol with forced ignition.

The commitment of global cruise shipping companies to sustainable development

ABSTRACT The intensive development of the cruising market in the last decade has had an adverse impact on the natural environment of destinations visited. Cruise ships moored at the quays close to city centres make a significant nuisance for local communities; with their engines running they make vibrations and noise in the ports and pollute the air by generating smog, and their fuel combusted contaminates the port waters and the atmosphere. Thousands of passengers going on trips cause congestion and traffic jams, generate noise and produce litter in the cities. Global cruise shipping companies treat care of the environment seriously. On the one hand, this is enforced by restrictive international regulations, national but also local ones, depending on the area of operation. However, on the other, this results from corporations who care about their image, and develop internal strategies and sustainable development policies, in particular, to reduce the emissions of harmful substances into the atmosphere and the environment. This article aims to identify and assess actions taken by cruise shipping companies for sustainable development. The results of the research can provide cognitive material for entities involved in the coastal area sustainable development, including local authorities, port authorities and cruise line operators.

INFLUENCE OF FOULING OF HEAT-EXCHANGE SURFACES OF CONDENSERS OF STEAM TURBINES ON THE CARBON OXIDE EMISSIONS

According to the strategy of environmental development of Ukraine until 2030, in order to increase the Environmental Performance Index (EPI), it is planned to reduce the energy intensity of GDP. One of the most polluting industries is the thermal power industry, and therefore reducing the emission of harmful gases, in particular nitrogen dioxide, is an important environmental problem. The share of electricity production by thermal power plants and thermal power plants in the electric power complex is significant, which leads to environmental risks due to large emissions and discharges of harmful substances by these enterprises into the environment. The magnitude of such emissions depends on the efficiency of the circulating cooling systems, which affects the rational use of fuel and water resources and, accordingly, the state of the environment. Increasing the temperature of the exhaust steam by reducing heat transfer through the contaminated heat exchange surface increases the pressure in the condenser of steam turbines and reduces the power of the turbine, which increases fuel consumption and increases the amount of emissions of harmful substances. One of these emissions is nitrogen dioxide, which is a harmful toxic compound and is classified as a greenhouse gas. The Purpose of the work is to calculate oxide carbon emissions depending on the thickness of the deposited layer on the heat exchange surface of the condensers of steam turbines of TPP. The concept of a particle of harmful emissions associated with the emergence and growth of a layer of pollution of the heat exchange surface of the condensers of steam turbines of TPP, expressed in fractions of a unit, is introduced, and an analytical expression is obtained for this value. Based on the theories of fuel combustion, heat transfer, as well as the concept of a part of harmful emissions associated with the emergence and growth of a pollution layer, the dependence of the amount of harmful emissions associated with fuel combustion at TPPs on the thickness of the pollution layer of the heat exchange surface of steam turbine condensers is obtained. Keywords: environmental pollution, thermal power plants, carbon monoxide, heat exchange surfaces.

Environmental and Energy Efficiency of Plywood Production Waste Burning

A comprehensive assessment of the energy and environmental efficiency of using plywood production waste as an energy fuel in steam watertube boilers units with a staged combustion scheme has been carried out. The components of the heat balance and emission of harmful substances are determined. The thermal engineering and granulometric characteristics, as well as the elemental composition of the combustible fuel and the formed focal residues, have been studied. Specific surfaces, porosity of entrainment particles were determined and their microscopic studies were performed. Specific surfaces, porosity of entrainment particles were determined and their microscopic studies were performed. It is concluded that it is necessary to modernize the ash cleaning system, and in the future to reconstruct boilers with the installation of tilt-pushing grids when implementing a layer-vortex combustion scheme.

Thermodynamic Analysis of Semi-Closed Cycles with Oxy-Fuel Combustion and Carbon Dioxide-Steam Working Fluid

Reducing emissions of harmful substances during the production of electricity at thermal power plants is possible by the transition to semi-closed gas turbine cycles with oxy-fuel combustion and carbon dioxide-steam working fluid. Their main advantages compared with closed Rankine cycles with water vapor and open Brayton cycles with combustion products of the air-fuel mixture are the absence of the toxic substances formation danger and the effective separation of working fluid components based on the thermodynamic principle, which allows to subsequently dispose of high-purity carbon dioxide. This paper presents the results of the energy performance thermodynamic analysis of the most known oxy-fuel combustion power cycles with a carbon dioxide-steam working fluid. A technique for modeling thermal schemes of promising power units is described in detail, taking into account losses for cooling high-temperature carbon dioxide turbines, energy costs for the production and compression of oxygen, as well as compression of carbon dioxide before disposal. Based on the results of mathematical modeling, it was found that the net electrical efficiency for the semi-closed combined cycle with oxy-fuel combustion can reach 44.5% at a gas turbine inlet temperature of 1400°C, and 43.2% for the Allam cycle at 1100°C.

Smoke Formation during Combustion of Biofuel Blends in the Internal Combustion Compression Ignition Engine

The proposed changes to the legislation on diesel cars require intensification of work on the possibilities of reducing emissions of harmful substances into the atmosphere by these vehicles. The subject of experimental research included in the manuscript was the Skoda Octavia with a 1.9 TDI (turbocharged direct injection) compression ignition engine (type 1Z). Light absorption measurements of smokiness of the exhaust gases emitted after combustion of various biofuels (conventional diesel, pure hydrotreated vegetable oil, hydrotreated vegetable oil, biobutanol) and their blends with fossil diesel fuel were studied. The measured light absorption coefficient is the reciprocal of the thickness of the layer, after passing through which the light has a ten times lower intensity. Its unit is the reciprocal of the meter (1/m or m−1). The results obtained by means of a standard smokiness meter indicate that the use of biofuels or their blends, in general, reduces smoke formation.