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A considerable number of Combined Heat and Power (CHP) systems continue to depend on fossil fuels like oil and natural gas, contributing to significant environmental pollution and the release of greenhouse gases. Two V-gutter flame holder prototypes (P1 and P2) with the same expansion angle, fueled with pure hydrogen (100% H2) or hydrogen–methane mixtures (60% H2 + 40% CH4, 80% H2 + 20% CH4), intended for use in cogeneration applications, have been designed, manufactured, and tested. Throughout the tests, the concentrations of CO2, CO, and NO in the flue gas were monitored, and particle image velocimetry (PIV) measurements were performed. The CO, CO2, respectively, and NO emissions gradually decreased as the percentage of H2 in the fuel mixture increased. The NO emissions were significantly lower in the case of prototype P2 in comparison with prototype P1 in all measurement points for all used fuel mixtures. The shortest recirculation zone was observed for P1, where the axial velocity reaches a negative peak of approximately 12 m/s at roughly 50 mm downstream of the edge of the flame holder, and the recirculation region spans about 90 mm. In comparison, the P2 prototype has a length of the recirculation region span of about 100 mm with a negative peak of approximately 14 m/s. The data reveal high gradients in flow velocity near the flow separation point, which gradually smooth out with increasing downstream distance. Despite their similar design, P2 consistently performs better across all measured velocity components. This improvement can be attributed to the larger fuel injection holes, which enhance fuel–air mixing and combustion stability. Additionally, the presence of side walls directing the flow around the flame stabilizer further aids in maintaining a stable combustion process. [ABSTRACT FROM AUTHOR]

A new afterburner installation is proposed, fueled with pure hydrogen (100%H2) or hydrogen–methane mixtures (60% H2 + 40% CH4, 80% H2 + 20% CH4) for use in cogeneration applications. Two prototypes (P1 and P2) with the same expansion angle (45 degrees) were developed and tested. P1 was manufactured by the classic method and P2 by additive manufacturing. Both prototypes were manufactured from Inconel 625. During the tests, analysis of flue gas (CO2, CO, and NO concentration), PIV measurements, and noise measurements were conducted. The flue gas analysis emphasizes that the behavior of the two tested prototypes was very similar. For all three fuels used, the CO2 concentration levels were slightly lower in the case of the additive-manufactured prototype P2. The CO concentration levels were significantly higher in the case of the additive-manufactured prototype P2 when 60% H2/40% CH4 and 80% H2/20% CH4 mixtures were used as fuel. When pure H2 was used as fuel, the measured data suggest that no additional CO was produced during the combustion process, and the level of CO was similar to that from the Garrett micro gas turbine in all five measuring points. The NO emissions gradually decreased as the percentage of H2 in the fuel mixture increased. The NO concentration was significantly lower in the case of the additive-manufactured prototype (P2) in comparison with the classic manufactured prototype (P1). Examining the data obtained from the PIV measurements of the flow within the mixing region shows that the highest axial velocity component value on the centerline was measured for the P1 prototype. The acoustic measurements showed that a higher H2 concentration led to a reduction in noise of approximately 1.5 dB for both afterburner prototypes. The outcomes reveal that the examined V-gutter flame holder prototype flow was smooth, without any perpendicular oscillations, without chaotic motions or turbulent oscillations to the flow direction, across all tested conditions, keeping constant thermal power. [ABSTRACT FROM AUTHOR]

The paper presents the energy consumption and emissions of pollutants in the exhausts during the take-off operation mission of a Short Take-Off and Landing (STOL) aircraft equipped with a traditional and hybrid propulsion system. This research is part of the contemporary trend of research aimed at reducing the impact of aviation on the natural environment. The analyzed propulsion system consists of turbine engines and electric motors cooperating with them. In this work, on the basis of data from flight tests, the energy requirement for the aircraft to perform the intended mission was determined. On this basis, fuel consumption and the corresponding pollutant emissions were determined for an aircraft with a traditional power unit. For comparison, an aircraft with a hybrid propulsion system with the same mass as an aircraft with a traditional propulsion system was used. Then, energy consumption, fuel consumption and emission of CO2, CO, NOx, VOC, PM10 and PM2.5 were obtained for both aircraft variants. The most important results of the conducted research include a reduction in CO2 emissions by 23% and NOx emissions by 46% in the case of the hybrid propulsion. This indicates potential benefits of using hybrid propulsion in aviation. [ABSTRACT FROM AUTHOR]

A considerable number of Combined Heat and Power (CHP) systems continue to depend on fossil fuels like oil and natural gas, contributing to significant environmental pollution and the release of greenhouse gases. Two V-gutter flame holder prototypes (P1 and P2) with the same expansion angle, fueled with pure hydrogen (100% H2) or hydrogen–methane mixtures (60% H2 + 40% CH4, 80% H2 + 20% CH4), intended for use in cogeneration applications, have been designed, manufactured, and tested. Throughout the tests, the concentrations of CO2, CO, and NO in the flue gas were monitored, and particle image velocimetry (PIV) measurements were performed. The CO, CO2, respectively, and NO emissions gradually decreased as the percentage of H2 in the fuel mixture increased. The NO emissions were significantly lower in the case of prototype P2 in comparison with prototype P1 in all measurement points for all used fuel mixtures. The shortest recirculation zone was observed for P1, where the axial velocity reaches a negative peak of approximately 12 m/s at roughly 50 mm downstream of the edge of the flame holder, and the recirculation region spans about 90 mm. In comparison, the P2 prototype has a length of the recirculation region span of about 100 mm with a negative peak of approximately 14 m/s. The data reveal high gradients in flow velocity near the flow separation point, which gradually smooth out with increasing downstream distance. Despite their similar design, P2 consistently performs better across all measured velocity components. This improvement can be attributed to the larger fuel injection holes, which enhance fuel–air mixing and combustion stability. Additionally, the presence of side walls directing the flow around the flame stabilizer further aids in maintaining a stable combustion process.

A new afterburner installation is proposed, fueled with pure hydrogen (100%H2) or hydrogen–methane mixtures (60% H2 + 40% CH4, 80% H2 + 20% CH4) for use in cogeneration applications. Two prototypes (P1 and P2) with the same expansion angle (45 degrees) were developed and tested. P1 was manufactured by the classic method and P2 by additive manufacturing. Both prototypes were manufactured from Inconel 625. During the tests, analysis of flue gas (CO2, CO, and NO concentration), PIV measurements, and noise measurements were conducted. The flue gas analysis emphasizes that the behavior of the two tested prototypes was very similar. For all three fuels used, the CO2 concentration levels were slightly lower in the case of the additive-manufactured prototype P2. The CO concentration levels were significantly higher in the case of the additive-manufactured prototype P2 when 60% H2/40% CH4 and 80% H2/20% CH4 mixtures were used as fuel. When pure H2 was used as fuel, the measured data suggest that no additional CO was produced during the combustion process, and the level of CO was similar to that from the Garrett micro gas turbine in all five measuring points. The NO emissions gradually decreased as the percentage of H2 in the fuel mixture increased. The NO concentration was significantly lower in the case of the additive-manufactured prototype (P2) in comparison with the classic manufactured prototype (P1). Examining the data obtained from the PIV measurements of the flow within the mixing region shows that the highest axial velocity component value on the centerline was measured for the P1 prototype. The acoustic measurements showed that a higher H2 concentration led to a reduction in noise of approximately 1.5 dB for both afterburner prototypes. The outcomes reveal that the examined V-gutter flame holder prototype flow was smooth, without any perpendicular oscillations, without chaotic motions or turbulent oscillations to the flow direction, across all tested conditions, keeping constant thermal power.

This paper conducts emissions and fuel consumption collaborative test of heavy-duty gasoline vehicle, which based on cold start with chassis dynamometer, the data analysis uses cold and hot coefficient weighting to evaluate the results. The research shows that the cold start has a great influence on the pollutants and CO2 emissions, which is mainly reflected in the 86.1% higher THC, 98.2% higher NOX, 65.0% higher CO and 34.8% higher CO2 of cold start cycle emissions compared with the hot start cycle emissions. The cold and heat weighted evaluation method can not only assessmen cold start cycle emissions, but also reasonably reflect the impact degree of cold start factors on emissions. The fuel consumption of cold start is 7.2% higher than that of hot start, the cold and heat weighted fuel consumption compared to the average fuel consumption of hot state is 1.0% higher. Therefore, it is necessary to add collaborative testing of emissions and fuel consumption of heavy-duty gasoline vehicles during cold start in the next phase of the standard

Waste tires have potential to be used for generation of fuel via thermal degradation because of their non-biodegradable nature. Nevertheless, the formation of various pollutants such as sulfur-based and nitrogen-based are inevitable due to presence of nitrogen and sulfur containing compounds during waste tires production. The main purpose was to examine the effect of variating heating rates on pollutants release because heating rate is an important parameter which influences the pollutants releasing profile. Moreover, Ar and CO 2 as reaction medium were used to identify their behavior for restraining the PAHs in gas phase. The present study investigates the influence of heating rates and carrier gas environment (Argon and CO 2) to reduce the pollutants emission. Thermogravimetry-Mass Spectrum coupled with Fourier transform infrared spectrometer was used to evaluate the thermal degradation and pollutants formation. The major degradation of waste tires occurred between 300 and 500 ℃. The sulfur-based (H 2 S, CS 2 , COS, SO 2, and CH 3 SH), nitrogen-based (NH 3 , HNCO, NO, and HCN) and 9 series of PAHs pollutants were detected. The higher heating rates promoted the pollutants emission. The degradation of compounds having sulfur content formed -SH radials and -SH helped in further release of sulfur based-pollutants. The NH 3 releasing profile started after 200 ℃ and released till around 800 ℃ for 30 ⁰C/min and 40 ⁰C/min but its emission was very low after 600 ⁰C for heating rates 5 ⁰C/min, 10 ⁰C/min, and 20 ⁰C/min. The aromatic compounds fraction was more at higher heating rate due to short residence time for pyrolytic products to go through secondary reaction. The 5 ℃/min and 10 ℃/min were considered favorable heating rates in terms of achieving lowest activation energy in both gas environments. The thermodynamic parameters analysis suggested that waste tires pyrolysis was non-spontaneous and endothermic reaction as well as feedstocks showed potential to be utilized for waste conversion. • Higher heating rates favor the formation of aromatic compounds. • Activation energy lowest at 5&10 °C/min heating rates for both gas environment. • Waste tires pyrolysis was non-spontaneous and endothermic reaction. • Heating rates affect PAHs release in Ar; 10 ℃/min shows lowest PAHs intensity. • CO2 vs Ar: Similar PAHs trends at 10 ℃/min optimal; PAHs peaks increase above 500 ℃ [ABSTRACT FROM AUTHOR]

The emissions of pollutants by waste-to-energy power plants, which contain more toxic substances owing to the complicated composition of municipal solid waste (MSW), such as NOx, SO2, HCl, HF, particulate matter, and heavy metals, has attracted increasing attention worldwide. To effectively control the pollutants, a flue gas cleaning system is indispensable in the operation of MSW incineration power plants. In this study, the flue gas cleaning system in a waste-to-energy power plant with flue gas recirculation (FGR) was evaluated. The concentrations of various pollutants were measured and compared with the standards at home and abroad. The results indicated that NOx emission can be effectively reduced by FGR, and that the emission concentration of NOx may meet the national emission standards only by adopting FGR. However, the emission levels of HCl and PM exceeded the limits in legislative standards; therefore, operation optimization or retrofit of a deacidification system and bag filter were proposed to comply with the international standards and near-zero-emissions goal. [ABSTRACT FROM AUTHOR]

In order to reduce pollutant emission from substation fires into the soil environment, developing technology to remove pollutants in soil after substation fires is necessary. Among the soil remediation technologies, thermal desorption has been proven to be an effective soil remediation method. In this paper, the effects of thermal desorption temperature and atmosphere on the releasing characteristics of pollutants in the soil polluted by waste oil in the accident oil pool in the substation were examined. The results showed that when the thermal desorption temperature was 500 °C, a large number of macromolecular organics decompose from the solid phase and change into long-chain alkanes and macromolecular acids under pure N2 atmosphere. When the thermal desorption temperature was higher than 500 °C the pollutants in the soil were further decomposed into small molecular organics. In addition, the organics were transformed to CO2, SO2, NOx, and CO under 20% O2/N2 atmosphere when the temperature was above 500 °C. [ABSTRACT FROM AUTHOR]

As a typical industrial city, Linyi has suffered severe atmospheric pollution in recent years. Meanwhile, a high incidence of respiratory and circulatory diseases has been observed in Linyi. The relationship between air pollutants and the prevalence of respiratory and circulatory system diseases in Linyi is still unclear, and therefore, there is an urgent need to assess the human health risks associated with air pollutants. In this study, the number of outpatient visits and spatial distribution of respiratory and circulatory diseases were first investigated. To clarify the correlation between diseases and air pollutant emissions, the residential intake fraction (IF) of air pollutants was calculated. The results showed that circulatory and respiratory diseases accounted for 62.32% of the total causes of death in 2015. The incidence of respiratory diseases was high in the winter, and outpatient visits were observed for more males (60.9%) than females (39.1%). The spatial distribution suggested that outpatient visits for respiratory and circulatory diseases were concentrated in the main urban area of Linyi, including the Hedong District, Lanshan District, and Luozhuang District, and especially at the junction of these three areas. After calculating the IF combined with the characteristics of pollution sources, meteorological conditions, and population data, a high IF value was concentrated in urban and suburban areas, which was consistent with the high incidence of diseases. Moreover, high R values and a significant correlation (R > 0.6, p < 0.05) between outpatient visits and residential IF of air pollutants imply similar spatial distributions of outpatient visits and IF value of residents. The spatial similarity of air pollution and outpatient visits suggested that future air pollution control policies should better reflect the health risks of spatial hotspots. This study can provide a potentially important reference for environmental management and air pollution-related health interventions. [ABSTRACT FROM AUTHOR]

Environmental quality is strongly coupling with the result of emissions reduction in most countries, while emissions reduction is influenced by the diversity of control policies, engineering facilities and development patterns. Further, local in which technical or policy that concern the control of target emissions will impact other pollutants emission. In China, the emissions of both CO2 and other pollutants increased substantially during the past decades. With the development of emissions reduction, it promoted a considerable risk of emissions spillovers caused by the present mechanism. In this study, we assessed the contributions of emissions spillovers to emission reductions by applying a more comprehensive indicator of pollutants, pollutant discharge fee (PDF), at the national, regional and provincial levels. The results shown positive and significant mutual effect between the PDF and CO2 emissions. That is, CO2 emission is significantly related with the process of other pollutants emissions reduction. Additionally, the positive correlation indicated further increases with the Five-Year Plan (FYP) cycle. Emissions spillovers have become an urgent risk for China. With the performance change, emissions reduction and environmental governance should heighten integration. Regional-level and provincial authorities must reconsider the matched emissions sustainability responsibilities and policies to avoid emissions spillovers and achieve meaningful emission controls. The study therefore suggested that a hierarchy of emission reductions, in the hope to promote emission reductions, improve environmental quality and contribute greenhouse gas reductions.

Abstract This paper reports numerical investigation on combustion characteristics, NO and CO emission for the optimization and simulation of gas instantaneous water heater operation with partial premixed combustion. A 3D model in real dimensions is performed using Computational Fluid Dynamics (CFD) to simulate the gas instantaneous water heater, including burner, combustion zone and heat exchanger. Comparisons between numerical and experimental results show that the simulation can predict flow field, temperature field, NO and CO concentration fields in the gas water heater with acceptable accuracy. The effects of fire holes distribution primary air coefficient, air ratio on NO and CO emission are all investigated. [ABSTRACT FROM AUTHOR]

Agriculture is responsible for considerable environmental impact. Much of the impact is related to mechanisation and, in particular, to tractor emissions. Agricultural tractor manufacturers have been forced to adhere to increasingly stringent limits on engine exhaust gas emissions in recent decades. Among the most recent technical solutions to reduce pollutant emissions are included Exhaust Gas Recirculation (EGR) and Selective Catalytic Reduction (SCR), both of which involve critical issues, such as the increase in specific fuel consumption (EGR) or the consumption of a urea solution (SCR). Only a few studies have focused on the environmental consequences related to the application of these solutions to operational agricultural tractors to date. This study employed the life cycle assessment approach to evaluate the environmental impact of ploughing conducted with two very similar tractors, the first being equipped with EGR and the second with SCR. More in details, considering a full set of environmental indicators, the environmental impact of ploughing carried out with the tractor equipped with the EGR is compared with the ones carried out with the tractor equipped with SRC. The results show that the SCR-equipped tractor reduced all the impact categories affected by NO X and particulate matter emissions (from −59% for acidification to −73% for marine eutrophication). However, the influence on Climate Change was much lower (−3%), mainly for the increase of Freshwater Eutrophication (due to the consumption of urea solution in the SCR, as well as to the consumption of tractor, and metal depletion for the higher mass of the tractor). Highlights • Tractors must adhere to stringent limits on engine exhaust gas emissions. • Exhaust Gas Recirculation (EGR) was compared to Selective Catalytic Reduction (SCR). • The environmental consequences related to these solutions were evaluated using LCA. • SCR-equipped tractor reduces the impacts affected by NO X and PM emissions. • EGR-equipped tractor reduces freshwater eutrophication and metal depletion. [ABSTRACT FROM AUTHOR]

Now a days gas turbines are widely used in the transportation and energy industry. According to Combustion of fossil fuels in these engine, environmental concerns have increased due to production of nitrogen oxides and carbon monoxide. Various methods have been offered to reduce the emission of pollutants. One of these methods is adding steam or water to the combustion chamber to reduce the flame temperature. Different methods can be applied to add steam to the combustion chamber, in this study, the steam is added to the diffuser and premixed with air into the combustion chamber. Steam addition influences the combustion process inside the combustion chamber, which should be considered during the combustion chamber design process. Therefore, a model for the conceptual design of the chamber geometry and the effect of adding steam on it will be presented. For this purpose, the data from an actual combustion chamber will be used to compare results of geometry design by using this model and to study the influence of steam on the chamber geometry. To investigate the combustion chamber performance, the chemical reactor network method for combustion modeling will be used. First, with this procedure an annular conventional combustion chamber will be modeled without steam addition and the results of this method will be compared with the actual data of this combustor. Then the effect of adding steam on the performance will be investigated. The study will show adding steam is an effective way to reduce the flame temperature and emission of pollutants. [ABSTRACT FROM AUTHOR]

This paper presents possible variants of reducing the heat loss in an existing heating network made from single pre-insulated pipes located in central Europe. In order to achieve this aim, simulations were carried out for five different variants related to the modification of the network operation temperature, replacement of a single network with a double pre-insulated one, and changes in the cross-section geometry of the thermal insulation of the double heating network from circular to egg-shaped. The proposed egg-shaped thermal insulation was obtained by modifying the shape of the Cassini oval, in that the supply pipe has a greater insulation thickness compared to the return pipe. The larger insulation field in the supply pipe contributed to reducing the heat flux density around the supply line and, as a result, to significantly reducing heat loss. The egg-shaped thermal insulation described in the publication in a mathematical formula can be used in practice. This work compares the heat losses for the presented variants and determines the ecological effect. Heat losses were determined using the boundary element method (BEM), using a proprietary computer program written as part of the VIPSKILLS 2016-1-PL01-KA203-026152 project Erasmus+.

This paper presents the analysis of the heat conduction of pre-insulated double ducts and the optimization of the shape of thermal insulation by applying an elliptical shape. The shape of the cross-section of the thermal insulation is significantly affected by the thermal efficiency of double pre-insulated networks. The thickness of the insulation from the external side of the supply and return pipes affects the heat losses of the double pre-insulated pipes, while the distance between the supply and return pipes influences the heat flux exchanged between these ducts. An assumed elliptical shape with a ratio of the major axis to the minor half axis of an ellipse equaling 1.93 was compared to thermal circular insulation with the same cross-sectional area. All calculations were made using the boundary element method (BEM) using a proprietary computer program written in Fortran as part of the VIPSKILLS project.

This study investigates the effects on engine performance and exhaust emissions using carbon coated aluminium (Al@C) nanoparticles as additives in palm oil methyl ester biodiesel. The nanoparticles were blended with the biodiesel fuel in the mass fractions of 30 ppm under ultrasonic mixing. A series of experimental tests have been conducted using a heavy-duty diesel engine test bench provided by Cummins. The influences of three kinds of biofuel, including biodiesel, biodiesel with ethanol, and biodiesel with ethanol and nanoparticles, have been studied in detail. The results show clearly that adding Al@C nanoparticles can reduce brake specific fuel consumption (BSFC) remarkably with average of 10%. NOx and CO emission reduce significantly in nanoparticles fuel blends cases at about 12% and 9% respectively, comparing with neat biodiesel. However, total hydrocarbon compounds (THC) emission and emitted particle numbers increase with adding nanoparticles. [ABSTRACT FROM AUTHOR]

In order to assess the performances of the domestic heating boilers with a CE mark, a wood pellets fired condensing boiler has been purchased and installed in the Laboratory for tests. The objective of the study was not only to check the announced performances, but mainly to investigate the influence of the different parameters affecting the functioning of the boiler, the thermal efficiency and the pollutants (NO x and CO) emission being aimed at. Tests have been performed to study the influence of the cycling frequency of the burner functioning, the overall excess air, the return water temperature, and the output power of the boiler. As announced by the manufacturer, the tested boiler fulfils the requirements of the Blue Angel Label, but the recommended value for the excess air (1.2) can be reduced to a value of about 0.4 without excessive emission of CO. The boiler could perform better if the ON period of the cycle of the burner is increased, even better if the OFF period is suppressed. The NO x are mainly formed from the nitrogen content of the pellets and their emission can only be reduced by a lower nitrogen content of the pellets than the limit stated in the standard. Random peaks observed in the evolution of CO, the boiler being operating in steady state regime, are attributed to the combustion process of pellets which is a non-continuous process by nature. [ABSTRACT FROM AUTHOR]

In this work, the results coming from the schedule optimization of a residential natural gas-fired CHP system operating according to a novel heat-driven operation strategy, based on the possibility to dump part of the thermal energy produced by the CHP system, are compared with the ones relative to the case in which the CHP system operates following a heat-driven strategy allowing load partialization. The effects of the variation of the size of the thermal energy storage system on the optimization results are also investigated. The simulation of the two different operation strategies has been realized using a numerical code written in Matlab environment, and a heuristic algorithm has been used for the economic optimization of the operation relative to both the implemented strategies. From the economic point of view, results show that the difference between the best CHP system configuration in the case with heat dumping and the one relative to the case with load partialization is minimal, with the latter presenting a slightly higher economic performance. Moreover, conditions in which heat dumping could yield higher economic performances than load partialization are also presented in this work. As concerns pollutants emissions, results show that the impact of load partialization on a local scale is much higher, with CO emissions that can be up to three times the ones relative to conventional systems for the separate generation of electricity and heat. [ABSTRACT FROM AUTHOR]

The influence of co-combustion of bituminous coal and pickling sludge on SO 2 , NO x , HF, HCl and PCDD/Fs emissions was studied in a drop tube furnace. To simulate the combustion condition of suspension firing boilers, the experiment was performed at 1100–1400 °C with the share of sludge in the feed ranging from 0 to 10% by weight. The combustion characteristics of coal and of blended fuels were studied by TG analysis. The results showed that the average combustion efficiency of co-combustion of bituminous coal and pickling sludge in the drop tube furnace is larger than 99%. SO 2 , NO x and HCl emissions had an increasing tendency with the temperature rising, but HF emissions were not sensitive to temperature. SO 2 and HF emissions had a rising trend with increasing share of sludge, while NO x and HCl emissions had an opposite trend. No obvious effect of temperature and the share of sludge on the total TEQ of PCDD/Fs was found, and the emissions of the seventeen congeners were basically stable under different experimental conditions. TG results showed that the combustion characteristics of coal and blended fuels were basically the same. XRD results showed that the ash composition changed significantly with the addition of sludge. Compared to the national standard, when co-combusting of bituminous coal and pickling sludge in commercial power plant, desulphurization and denitrification equipment, activated carbon injection and baghouse should be provided. [ABSTRACT FROM AUTHOR]

The importance of energy-efficient power generation that effectively utilizes the available fossil fuels is increasing due to the gradual decline in fossil fuel reserves. Furthermore, concern about global warming has led to rapid growth in renewable energy and energy storage technologies. This trend is encouraging power utilities to effectively exploit the use of renewable energy resources (RESs) and energy storage facilities (ESFs) for power supply systems. In this regards, trigeneration in the presence of RESs and ESFs can play an important role for efficient and clean power dispatch. This paper discusses the optimum power dispatch using a hybrid power plant consisting of trigeneration-based thermal plants, RES-based plants, and energy storage facilities. Mathematical modeling of such a dispatch problem is formulated and the analysis is carried out using MATLAB simulations. Results show that considerable reduction in fuel utilization and pollutants emission can be achieved using such hybrid plants by using the optimum power dispatch proposed here. [ABSTRACT FROM AUTHOR]

An analysis of statistical data has shown that most Russia's cities with unfavorable ecological conditions refer to the Siberian Federal District. This is due to considerable amounts of atmospheric emissions from large industrial enterprises with imperfect equipment and technologies as well as to the unfavorable conditions of diffusion of dust and gas emissions. Attention is given to the role of nonferrous metallurgy, including aluminum smelting, in environmental impairment. It is shown that the pollutant emissions not only pollute the atmosphere, but also when returning to land surface, they alter the soil-geochemical habitat conditions for vegetation and animals and lower the quality of human life. The shifting of aluminum smelters to Siberia and the construction of major plants pose a threat of impairment in the ecological situation over a significant part of the territory, which is illustrated with the impact of pollutants from several aluminum smelters. Thus, in spite of the fact that the aluminum smelters of Khakassia are provided with up-to-date equipment, their 30-year-long operation has led to formation of a technogenic geochemical anomaly with an area of about 80 km, containing 0.05 to 0.2% of the total amount of fluorine in the 0-15 cm topsoil, and water-soluble fluorine from 1 (10 mg/kg) to 3 MAC. The investigations show that the Soderberg method when used to obtain aluminum in large amounts (0.8-1 mln. t per year) is not as ecologically safe as advertised. It is therefore necessary to perfect the technologies used or to decrease the amount of aluminum produced. [ABSTRACT FROM AUTHOR]

In the industry, resistance welding has always been regarded as the process without significant adverse effect on the work environment. The research literature of the last years dealing with investigations into fume and chemical factors of resistance welding was the only reason that has directed the attention of specialists on working safety to the amount and type of pollutants emitted during this process. The article presents research, conducted at Instytut Spawalnictwa in Gliwice, into the emission of pollutants generated during spot resistance welding of steel plates with various protective coatings. The article demonstrates the research station and methodology of determination of total fume, carbon monoxide, nitrogen oxides and organic matters. The examination of fume and gas emission was conducted during resistance welding of electrolytic and hot-dip coated plates, covered with zinc, zinc-iron alloy, aluminium with the admixture of silicon as well as zinc-epoxy double layer coatings. The comparative analysis of the research results was aimed at the determining the impact of coating type and welding current on emission of fumes and gases during resistance welding of plates with different thickness. [ABSTRACT FROM AUTHOR]

Overall pollutants emission from impinging premixed and diffusion flames were measured by investigating its dependence on burner-plate separation distance, fraction of hydrogen in the biogas-hydrogen mixture, Reynolds number and equivalence ratio. Results show that premixed flame is cleaner with both low CO and NO x emissions than diffusion flame, either under open or impingement conditions. Impinging flame emits more CO while less NO x than the corresponding open flame. For both premixed and diffusion flames, CO emission firstly increases at separation distance of H < 15 mm and then decreases at H > 15 mm. While NO x emission monotonically increases with H . NO x emission also increases with fraction of hydrogen, equivalence ratio and Reynolds number, due to its dependence on both temperature and volume of the flame. The lowest CO emission occurs at the slightly rich condition at equivalence ratio of 1.2. This low CO emitting behavior is favorable for cooking applications, where slightly fuel rich flames are adopted. [ABSTRACT FROM AUTHOR]

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This work deals with the effects of the heat dumping on the operation of four residential micro-CHP (combined heat and power) systems, each composed of a prime mover producing electricity and heat, a thermal energy storage system and an auxiliary boiler. The micro-CHP systems differ from one another on the prime mover, while the same multi-apartment housing situated in Italy has been considered as user. Four natural gas fueled commercial prime movers have been considered, two internal combustion engines and two microturbines, characterized by different electric and thermal powers. For each micro-CHP system, two heat-driven operation strategies, one with heat dumping and one without have been implemented by means of a home-made numerical code developed in Matlab environment, and in both the cases the economic optimization of the operation has been performed using the pattern search algorithm. For each analyzed case, the results are reported in terms of prime mover operating hours, thermal and electrical energy production, natural gas consumption, primary energy and economic savings with respect to separate generation of electricity and heat, and pollutants emission. The results of an economic analysis are also reported. The effects of the variation of the maximum capacity of the thermal energy storage system, and of the auxiliary boiler efficiency on the optimization results are analyzed, and the results relative to the two different operation strategies are compared and discussed. The major result of this study is that, for all the analyzed micro-CHP systems, an optimized application of heat dumping in the micro-CHP system operation permit to considerably reduce the size of the thermal energy storage system with respect to the heat-driven operation strategy without heat dumping. [ABSTRACT FROM AUTHOR]

Abstract: Diesel particulate filters are a standard technology used in diesel engines in order to comply with actual and forthcoming regulations, regarding soot emissions and particulate matter in exhaust gases. In recent years, pre-turbo aftertreatment response has been investigated as opposed to the traditional aftertreatment location downstream from the turbine but just regarding engine performance. Previous studies do not deal in detail with gaseous and particle emission analysis in a pre-turbo aftertreatment configuration. This paper focuses on these topics. The gaseous and particle emissions have been assessed in a 4-cylinder, light-duty diesel EURO 4 engine typically used in European passenger car vehicles. Different steady-state operating points have been considered in order to extend the study over a wide range of operating conditions. Additionally, the New European Driving Cycle has been performed with the aim of reaching a comprehensive understanding of the aftertreatment dynamic response in terms of pollutant emissions. An increase in the amount of NO2 converted from NO and a reduction in emitted CO have been found at low load steady-state operating conditions with pre-turbo aftertreatment placement. In driving cycle conditions, a shift from nucleation to accumulation mode particles have been found, being the filtration efficiency scarcely affected. [Copyright &y& Elsevier]

The main technological operations for producing the sinter used for preparing the hot metal in the furnace are: preparation and transport of raw materials used for producing the sinter (transport, storage, crushing, sorting ore and coke); sintering the raw materials during the sintering tape preparation (cooling, smashing, sorting) and transport of the sinter.

Abstract: The methane enrichment with hydrogen amounts can improve environmental and mechanical performances of an ICE (internal combustion engine). The paper presents data resulting by the experimental campaign carried out over 42 days on a demo commercial CHP (combined heat and power) (60 kWel) fuelled with hydrogen enriched methane blends. The tests have been carried out at partial load 55 kWel with hydrogen percentages of 0%, 5% and 8%. In order to evaluate the CHP energy consumption and environmental performance, the analysis was conducted for 336 h, using a continuous flue gas analyzer and two mass flow metres for hydrogen and methane. The aim of this paper is to demonstrate how the use of the hydrogen enrichment in a CHP plant represents a valid alternative to the same commercial energy systems, regarding the CO and CO2 emissions avoidance. The data analysis shows that modifying engine settings and increasing hydrogen amount significant energy effects occur. Consequently, the CHP fuelled with mixtures provides a lower thermal power, penalizing the heat recovery efficiency. The energy losses are due to unrecovered heat which is wasted like sensible heat to the stack. This alternative feeding system was developed in order to assess the energy penalty related to this carbon avoidance technique. [Copyright &y& Elsevier]

Discharges and emissions in the coal mining process have a strong effect both on the environment and on human health. This problem is usually be a negative one and has only been recognized qualitatively, due to the lack of effective quantitative methods. Based on emergy theory and accounting methodology, a set of quantitative methods for accounting the environmental support due to pollutants emissions was first introduced. Then impacts on environment and effects on human health were quantified using the unified units. The results indicated that water pollutants caused more impacts on the environment than air pollutants did, i.e., more environmental contributions are needed to dilute and absorb water pollutants. The occupation of land caused by coal mining gangue waste stacking has led to a huge loss of environmental services over the years. Moreover, the potential damage on the human condition health caused by CO through climate change cannot be ignored. Finally, the impacts of mining activities on environmental and human health in unified units are shown to provide a quantitative insight into the disadvantage of coal mining. The comparable results of the method indicate the different influence of various pollutants and the contribution of 'natural capital' directly. This work is a part of ongoing thermodynamic input-output analysis and life cycle analysis of coal mining systems (which are in process.) [ABSTRACT FROM AUTHOR]

Large-Eddy Simulation (LES), coupled with the Conditional Moment Closure (CMC) sub-grid model and the GRI3 detailed chemical mechanism, are used to explore the structure of the Delft III piloted turbulent non-premixed flame. The use of a quite refined multi-dimensional CMC grid and the detailed chemistry, together with the capability of LES to follow local fluctuations of the scalar dissipation, allow the prediction of localised extinctions and re-ignitions in locations consistent with experiment. The statistics of velocity, mixture fraction, temperature, mass fractions of the major species and of OH are overall in good agreement with experimental data. Carbon monoxide is captured very well, but NO is overpredicted, perhaps due to inherent limitations of the GRI3 scheme to capture NO emissions. [ABSTRACT FROM AUTHOR]

Present study provides the comprehensive investigation on the different characteristics of MILD oxygen-enriched and oxy-methane combustion such as heat transfer, ignition delay, flame color, flame structure, emissions of CO and NO x (as air pollutants) by the adding of CO 2 to the oxidizer. The MILD furnace of the University of Lisbon is modeled using the standard k-ε turbulence model and detailed chemical mechanism of GRI2.11. Original, extended and new optimized EDC ("EDC2020") models are applied for the turbulence-chemistry interaction modeling. Additionally, a perfectly stirred reactor (PSR) analysis alongside with CFD simulation is used for better understanding the combustion process. The results indicate that by replacing of CO 2 with N 2 , emission of visible light is reduced significantly and maximum temperature drops noticeably until flame reaches to nozzle shape section of furnace. Moreover, it is found that MILD oxygen-enriched and oxy-methane combustion have regarded advantages than MILD methane-air combustion involving enhancing the temperature uniformity about 10–15%, more distributed reaction zone and a significant reduction of NO x emission. CO emission shows different behavior and is unchanged under MILD oxygen-enriched regime while it increases from 11 ppm in MILD methane-air to 140 ppm in MILD oxy-methane with injection of 90% CO 2 mass fraction. • Increasing temperature uniformity by replacement of N 2 with CO 2 in the oxidizer. • Reduction of visible light emission by moving to the flameless oxy-fuel combustion. • Improving the efficiency of furnace under the flameless oxy-fuel combustion mode. • Increasing of CO 2 in the oxidizer is desirable in terms of NO x emissions. • Growth of ignition delay time under MILD oxygen-enriched and oxy-fuel combustion. [ABSTRACT FROM AUTHOR]

• Primary gaseous and PM emissions in combustion of Bulgarian biomass in fluidized bed. • Effects of fuel particle mass, temperature, excess of oxygen and biomass type. • NO was formed mainly from fuel bound N, with highest emissions in biomass containing kernel or cereal. • Submicron PM was dominant and highly affected by the availability of volatile matter and the ash composition. • PM measured in char combustion was significantly reduced, reflecting the lack of volatiles. The present work aimed at investigating the effect of several operating parameters on the experimentally measured primary gaseous products and particulate matter (PM), as well as on the reaction rate and the total conversion, obtained during single particle combustion of biomass in fluidized bed conditions. In focus were the following operating parameters: initial mass of the fuel particle (ranging between 0.1 and 0.5 g), oxygen partial pressure (from 5 to 21 kPa), bed temperature (between 700 and 900 °C) and biomass type. The experiment was carried out at atmospheric pressure, using five different types of solid biofuels. The primary carbon conversion products were carbon dioxide (CO 2) and carbon monooxide (CO). The fuel bound nitrogen was converted mainly to nitrogen monooxide (NO). However, biomass having higher nitrogen content showed lower nitrogen conversion to NO, but higher absolute NO emissions. Particulates of submicron size, with unimodal size distribution, were the dominant fraction of particulate emissions for all fuels. The mass normalized PM concentration was reduced by three orders of magnitude during char combustion, thus supporting the hypothesis that PM formation is highly affected by the availability of volatile matter and the ash composition. [ABSTRACT FROM AUTHOR]

The paper presents an analysis of heat loss and reductions of annual emissions of air pollutants of a quadruple pre-insulated heating network by comparing this solution with the existing pre-insulated network consisting of four pre-insulated single pipes and the variant consisting of two twin pipe pre-insulated. For calculations, an existing heating network located in central Poland was adopted, where heat is transported for heating purposes of buildings and domestic hot water with circulation of domestic hot water through four separate pre-insulated underground pipes. The idea of the construction of four pre-insulated pipes presented in the paper consists in the location of four steel pipes in a common round thermal insulation, which perform the role of heat transport for heating purposes in multi-family buildings (supply and return) and two pipes transporting hot water (a pipe with domestic hot water with circulation). In Poland, heating pipes used in multi-family housing have a larger diameter compared to domestic hot water pipes, which is why standard twin pipe heating pipes have been used in the construction of four pre-insulated networks, in which the domestic hot water pipe has been added to the thermal insulation and circulation of domestic hot water. In order to determine heat losses, a simplified two-dimensional model of conductive heat transfer was developed using Fortran to create a computer program. The results of numerical simulations show that the use of twin pipes for the construction of pre-insulated quadruple networks has contributed to a significant reduction in heat loss in relation to the existing single pre-insulated network (up to 57.1%), while reducing the thermal insulation field of the cross-section of the pre-insulated pipe by 21.4%. [ABSTRACT FROM AUTHOR]

This paper presents possible variants of reducing the heat loss in an existing heating network made from single pre-insulated pipes located in central Europe. In order to achieve this aim, simulations were carried out for five different variants related to the modification of the network operation temperature, replacement of a single network with a double pre-insulated one, and changes in the cross-section geometry of the thermal insulation of the double heating network from circular to egg-shaped. The proposed egg-shaped thermal insulation was obtained by modifying the shape of the Cassini oval, in that the supply pipe has a greater insulation thickness compared to the return pipe. The larger insulation field in the supply pipe contributed to reducing the heat flux density around the supply line and, as a result, to significantly reducing heat loss. The egg-shaped thermal insulation described in the publication in a mathematical formula can be used in practice. This work compares the heat losses for the presented variants and determines the ecological effect. Heat losses were determined using the boundary element method (BEM), using a proprietary computer program written as part of the VIPSKILLS 2016-1-PL01-KA203-026152 project Erasmus+. [ABSTRACT FROM AUTHOR]

This paper presents the analysis of the heat conduction of pre-insulated double ducts and the optimization of the shape of thermal insulation by applying an elliptical shape. The shape of the cross-section of the thermal insulation is significantly affected by the thermal efficiency of double pre-insulated networks. The thickness of the insulation from the external side of the supply and return pipes affects the heat losses of the double pre-insulated pipes, while the distance between the supply and return pipes influences the heat flux exchanged between these ducts. An assumed elliptical shape with a ratio of the major axis to the minor half axis of an ellipse equaling 1.93 was compared to thermal circular insulation with the same cross-sectional area. All calculations were made using the boundary element method (BEM) using a proprietary computer program written in Fortran as part of the VIPSKILLS project. [ABSTRACT FROM AUTHOR]

The relationship between economic growth and environmental pollution has long been a controversial topic. However, simply the detection of the existence of environmental Kuznets curve (EKC) is not enough to understand how economic growth induced environmental pollution. This study investigated the path and mechanism of the effect of economic growth on the emission of two types of environmental pollutants, that is, industrial smoke and dust and sulfur dioxide, by using a structural equation model and a sample of 283 prefecture-level cities in China in 2005 and 2015. The research results show that economic growth exerted both direct and indirect effects on the emission of the two environmental pollutants. In addition to a direct impact through the economic scale effect, economic growth also indirectly impacted the two environmental pollutants emissions through three mediators, that is, industrial structure, technological innovations and environmental regulations. For different pollutants, the effect paths of economic growth on their emission showed both similarities and differences. First, with regards to industrial smoke and dust emissions and sulfur dioxide emissions, the effects of economic growth on the amount of these two emissions through environmental regulations and the industrial structure were negative inhibitory effects and positive promoting effects, respectively. This means that in prefectural-level cities in China, environmental regulation factors have produced some effects in reducing the emissions of these two pollutants while the industrial structure (level of industrialization) can increase the emissions of these two pollutants. However, the effect strength of these two paths shows a gradual weakening. Second, these two paths differ in effect strength and its changes. The positive promoting effects of the industrial structure on pollutant emission are significantly higher than the inhibitory effects of environmental regulation. In addition, our study also found that the direct impact path of economic growth on environmental pollution also passed significance testing, particularly in 2015. This shows that other reasons affect pollutant emission, such as system factors, spatial migration of industries and so forth. [ABSTRACT FROM AUTHOR]