Combustion Of Fuels Research Articles

Effects of Primary Energy Consumption and Alternative Energy Patents on CO2 Emissions in China

China’s significant carbon emissions have attracted global attention, and the country has committed to reaching a peak in carbon emissions before 2030 and achieving carbon neutrality by 2060. It is crucial to achieve this goal by effectively controlling the combustion of primary fuels and developing alternative energy technologies. The existing literature has studied the effects of primary energy consumption on CO2 emissions, alternative energy technology on CO2 emissions, and energy patents on CO2 emissions. However, there are few studies on the effects of the relationship between primary energy consumption and alternative energy technology patents. This study analyzes the effects of primary energy consumption and alternative energy patents on CO2 emission intensity and CO2 emissions per capita, and their relationship using canonical correlation analysis. Our results are as follows. First, CO2 emissions from natural gas and liquefied petroleum gas have positive effects (correlation coefficients of 0.102 and 0.275, respectively), while CO2 emissions from gasoline, fuel oil, diesel, and kerosene have negative effects on CO2 emission intensity (correlation coefficients of −0.767, −0.420, −0.138, and −0.035, respectively). Second, patents for devices for producing mechanical power from muscle energy have large positive effects on total CO2 emissions (correlation coefficient of 0.533). Finally, the more the patents utilize waste heat, geothermal energy, hydro energy, and wind energy, the higher the CO2 emissions from liquefied petroleum gas, gasoline, and crude oil, and the lower the CO2 emissions from diesel, which are conducive to controlling CO2 emissions. Therefore, energy policies will be more effective, improve the living environment, and promote sustainable development based on the CO2 emissions level from primary energy consumption and the control degree of CO2 emissions by alternative energy.

Improvement of Engine Combustion and Emission Characteristics by Fuel Property Modulation

The sustainability of diesel engines has come to the forefront of research with the growing global interest in reducing greenhouse gas emissions and improving energy efficiency. The aim of this paper is to support the goal of sustainable development by improving the volatile properties of diesel fuel to promote cleaner combustion in engines. In order to study the effect of diesel fuel volatility on spraying, combustion, and emission, the tests were carried out with the help of the constant volume chamber (CVC) test rig and an engine test rig, respectively. CVC test: A high-speed video camera recorded the spray characteristics of different volatile fuels in a constant-volume combustion bomb. The effects of different rail pressures and ambient back pressures on the spray characteristics were investigated. Engine test: The combustion and emission characteristics of different volatile diesel fuels under different load conditions (25%, 50%, 75%) were investigated in a four-stroke direct-injection diesel engine with the engine speed fixed at 2000 rpm. The test results show that as the rail pressure increases and the ambient pressure decreases, the spray characteristics of the fuels tend to increase; for the more volatile fuels, although reducing the spray tip penetration, the spray projected area and spray cone angle increase, which is conducive to improving the homogeneity of the fuel and air mixing in the cylinder. The improvement of fuel volatility can form more and better-quality mixtures within the ignition delay time (ID), resulting in a 1–2% increase in peak cylinder pressure and a 2–4% increase in peak heat release. For different loads, pre-injection heat release is generated to redefine the ID and combustion duration (CD). Improved fuel volatility effectively reduces carbon monoxide (CO) emissions by about 8–10% and hydrocarbon (HC) emissions by about 13–16%, but it increases nitrogen oxide (NOx) emissions by about 8–11%. Analyzing from the perspective of particulate matter (PM), combined with the aromatic content of volatile fuels, it is recommended to use fuels with moderate volatility and aromatic content under low load conditions, and at medium to large loads, the volatility of the fuel has less weight on particulates and more weight on aromatics, so it is desirable to use the fuel with the lowest volatility and lowest aromatic content of the fuel selected.

GLOBAL WARMING: A COMPREHENSIVE ANALYSIS OF CAUSES, IMPACTS, AND SOLUTIONS

Global warming is one of the most critical environmental challenges facing humanity today, characterized by a significant increase in Earth's average surface temperature due to human-induced greenhouse gas emissions. This paper provides a comprehensive examination of the primary anthropogenic causes of global warming, including industrialization, deforestation, and changes in land use patterns. The burning of fossil fuels—such as coal, oil, and natural gas—for energy production and transportation has led to a dramatic rise in carbon dioxide levels in the atmosphere. This surge in CO2 concentrations has intensified the greenhouse effect, trapping more heat within the Earth's atmosphere and contributing to the overall rise in global temperatures. In addition to carbon dioxide, other potent greenhouse gases like methane and nitrous oxide, released from agricultural practices and industrial processes, exacerbate the warming effect. The expansion of industrial agriculture has significantly increased methane emissions, while synthetic fertilizers contribute to higher levels of nitrous oxide. Deforestation driven by agricultural expansion and urban development further diminishes the Earth's capacity to absorb carbon dioxide, releasing stored carbon and altering local climate patterns. The impacts of global warming are extensive, affecting ecosystems, weather patterns, and human societies worldwide. Rising sea levels threaten coastal communities, while changing precipitation patterns lead to more frequent and severe droughts and floods. This paper also discusses the interconnected nature of these factors and their complex feedback systems that amplify global warming effects. To address this multifaceted challenge, the paper proposes a comprehensive approach that includes transitioning to renewable energy sources, enhancing energy efficiency across all sectors, implementing sustainable land use practices, and fostering international cooperation through policy initiatives such as the Paris Agreement. Understanding these intricate relationships is crucial for developing effective strategies to mitigate and adapt to the challenges posed by global warming, ensuring a sustainable future for generations to come.

Deactivation Mechanism of Spent TiO2-Based Selective Catalytic Reduction (SCR) Catalysts and State-of-the-Art Recycling Technologies.

Nitrogen oxides (NOx) make up a group of gases that are mainly formed during the combustion of fossil fuels at high temperatures. NOx contributes to environmental degradation by forming acid rain and enhancing global warming. Exposure to air with a high concentration of NOx can aggravate respiratory diseases, particularly asthma. The elimination of NOx in practical applications mainly proceeds through selective catalytic reduction (SCR) of NOx with NH3 to harmless N2 and H2O. One practical issue of the SCR process is the deactivation of TiO2-based SCR catalysts. In addition, growing numbers of spent SCR catalysts present a serious waste-management challenge for recyclers at end of life. It is therefore crucial to disclose the deactivation mechanism of the spent TiO2-based NH3-SCR catalysts and propose effective recycling technologies for waste valorization. Here we outline the catalyst deactivation pathways for TiO2-based SCR catalysts and critically review methods of improving the direct sustainability of spent catalysts, in areas such as direct regeneration and recovery of spent catalysts. Through this review, the challenges, solutions, and future strategies for handling spent SCR catalysts are clarified for future studies of application on an industrial scale.

Ovule and seed development of crop plants in response to climate change

The ovule is a plant structure that upon fertilization, transforms into a seed. Successful fertilization is required for optimum crop productivity and is strongly affected by environmental conditions including temperature and precipitation. Climate change refers to sustained changes in global or regional climate patterns over an extended period, typically decades to millions of years. These shifts can result from natural processes like volcanic eruptions and solar radiation fluctuations, but in recent times, human activities—especially the burning of fossil fuels, deforestation, and industrial emissions—have accelerated the pace and scale of climate change. Human-induced climate change impacts the agricultural sector mainly through global warming and altering weather patterns, both of which create conditions that challenge agricultural production and food security. With food demand projected to sharply increase by 2050, urgent action is needed to prevent the worst impacts of climate change on food security and allow time for agricultural production systems to adapt and become more resilient. Gaining insights into the female reproductive part of the flower and seed development under extreme environmental conditions is important to oversee plant evolution, agricultural productivity, and food security in the face of climate change. This review summarizes the current knowledge on plant reproductive development and the effects of temperature and water stress, soil salinity, elevated carbon dioxide, and ozone pollution on the female reproductive structure and development across grain legumes, cereal, oilseed, and horticultural crops. It identifies gaps in existing studies for potential future research and suggests suitable mitigation strategies for sustaining crop productivity in a changing climate.

Experimental and numerical investigations on NH3/H2 fueled combustion in the combustor with block for improved micro power generation

To advance the application of zero-carbon fuels in micro-combustion, enhance energy conversion, and reduce NOx emissions in NH3/H2-fueled micro-power generators, a micro-combustor with an insertion block is proposed and tested under various chamber configurations and operational conditions. Experimental and numerical tests are conducted in micro-combustors with varied block settings, burner dimensions, NH3 blended ratios (mN), and fuel flow rates (Vf). The results indicate that mN significantly impacts the generation and consumption of H, O, and OH radicals, as well as NO, affecting flame regime and heat transfer. Specifically, adding 5∼15% NH3 improves the operating performance of the burner, with the highest mean temperature achieved in combustor #24C3-0.4 at mN=15%. Block insertion alters flame characteristics and enhances gas-wall heat transfer, the combustor with thinner blocks at higher mN and thicker blocks at lower mN contributes to better thermal performance. Furthermore, combustors with thinner blocks exhibit lower NO emissions. The working performance of the micro-thermophotovoltaic system can be enhanced by selecting the appropriate burner length with block thickness W=0.4 mm and position Lb=7 mm based on Vf. The maximum electrical power of 3.7 W is achieved with a burner length of 28 mm for the system using InGaAsSb cells at Vf=1200 mL/min.

An experimental study on flame propagation and combustion characteristics of multiple emulsified diesel and biodiesel fuel droplets

To unravel the interaction mechanism between droplets that is relevant for practical liquid fueled burners, the flame propagation characteristics of multi-droplet of emulsified diesel and biodiesel (FAME) fuels were studied using a suspended line droplet array. It was found that when S/d0 ≤ 3 (ratio of droplet spacing to initial droplet diameter), the double droplets were ignited simultaneously and surrounded by a single flame, and as the droplet spacing increased, two independent flames were formed around each droplet. The highest flame propagation rate was attained at S/d0 = 3, which was attributed to the consistent values of flame standoff ratio limited by the dominant heat conduction and finite evaporating rate. The droplet interaction, such as oxygen competition effect, enhanced with smaller droplet distance, can result in the reduction in the droplet combustion rate and flame propagation rate; the latter one, however, showed an increasing trend when small droplet or the size non-uniformity of droplet cloud was considered. In addition, the child droplet ejected from the emulsified droplets showed three burning modes and was an important factor promoting the flame spread, and the results showed that compared with the FAME emulsified fuels, the child droplets in diesel cases were more prone to ignition, expanding the burning regime.

ENVIRONMENTAL AND HEALTH IMPACTS OF AGRICULTURAL WASTE COMBUSTION FOR BIOENERGY: A TOXICITY AND EMISSION REVIEW

This study examines the environmental and health impacts caused by the release of polycyclic aromatic hydrocarbons (PAHs) from the combustion of biomass and agricultural waste. Today, bioenergy plays a crucial role in global energy systems, accounting for 70 % of renewable energy consumption, 9.5 % of total primary energy supply, and 13 % of global gross final energy consumption. However, environmental pollution remains one of the greatest challenges of the 21st century, with serious implications for human health, biodiversity, and climate change. PAHs, released during the incomplete combustion of organic fuels, are particularly concerning due to their carcinogenic and mutagenic properties. This review aims to evaluate the emissions of PAHs during biomass combustion, with a focus on fuel types and combustion conditions. It synthesizes data from over 30 contemporary scientific sources, comprehensively analysing PAH formation and distribution in flue gases, and identifies the key factors influencing these emissions. The research reveals that PAH emissions vary significantly depending on the type of biomass, combustion conditions, and the control measures employed. Open burning of agricultural residues generates much higher PAH concentrations compared to controlled combustion in stoves or furnaces. The analysis assumes consistent data reporting across studies and acknowledges that real-world conditions may differ from laboratory settings, potentially affecting emission levels. The findings underscore the importance of implementing effective emission control strategies to reduce environmental and health risks, particularly in regions like Ukraine that rely heavily on biomass as an energy source. By addressing a critical gap in the literature, this review enhances understanding of the long-term impacts of bioenergy on environmental health and sustainability and advocates for updating Ukrainian regulatory legislation with modern methodological procedures.

An Efficient Numerical Model for Fast Simulation of the Combustion of Alternative Fuels in a Cement Rotary Kiln

An Efficient Numerical Model for Fast Simulation of the Combustion of Alternative Fuels in a Cement Rotary Kiln

ANALYSIS OF POLLUTANTS EMISSIONS IN THE CONDITIONS OF COMBUSTION OF ALTERNATIVE AND TRADITIONAL SOLID FUELS

The problem of pollutant emissions and the correlation of emission values with climate change is an extremely urgent task today. Climate change is causing glaciers to melt, which is causing water levels in reservoirs to rise. The issues of environmental pollution by the products of combustion of solid fuels are becoming more and more relevant. Among the pollutants that enter the air after the combustion of fuel in the furnaces of boiler units, there are also greenhouse gases that stimulate the greenhouse effect, causing climate change. The work determines emission indicators and emissions of pollutants into the atmospheric air. The task of the work is to identify and recommend the use of modern and effective methods for reducing emissions of pollutants into the atmosphere. The work uses analytical articles and sites that raise the problem of climate change. The work also shows the results of calculating pollutant emissions from combined heat and power boilers, carried out according to the recommendations of national guidelines. A high value of dust emission is typical for straw and flax fescue. In terms of nitrogen oxide emissions, wood waste has the highest values. Slightly lower values for the emission of carbon dioxide, methane, NMVOC are determined for wood waste. It is important to note that when gaseous fuels are burned, there will be no emissions of suspended particulate matter. It should also be noted that natural gas and wood waste do not contain sulfur-containing compounds, which ensures the absence of sulfur dioxide in flue gases when fuels are burned. However, when gases are burned, mercury compounds can be released in trace amounts. One of the options for solving the problem is the transition to alternative energy sources. The development of such sources is already underway, but their implementation in practice, unfortunately, is slow.

Identification of Mass Transfer Mechanisms inside an Industrial Electrochemical Cell for CO2 to Formate Conversion through 2D Transient Modeling

Since the dawn of the industrial revolution, the Earth's atmosphere has experienced a gradual increase in carbon dioxide (CO2) concentrations, leading to the trapping of solar energy and consequent global warming. This shift in climate dynamics carries significant consequences, including heightened levels of secondary pollutants in urban areas and an increase in the frequency and severity of natural disasters. To address these pressing environmental challenges, there is a widespread global inclination toward adopting sustainable technologies and reducing CO2 and other greenhouse gas emissions [1,2]. However, the primary source of CO2 emissions remain the combustion of fossil fuels, which is expected to persist as the dominant energy source for the foreseeable future. It is driven by extensive usage across various sectors, notably in the chemical industry and transportation. Despite growing awareness of the need to curb greenhouse gas emissions, transitioning to viable alternatives in these sectors presents formidable challenges. Factors such as entrenched infrastructure, economic dependencies, and technological barriers complicate the shift away from fossil fuels, highlighting the complexity of the transition toward sustainable solutions [1,3]. The emergence of CO2 electrolyzers, which can be powered by various energy sources including renewable options like solar power, can redefine the production of chemicals, reducing our reliance on fossil fuels in this sector and thereby mitigating CO2 emissions. This shift offers a promising solution to address global warming problems. These devices facilitate the conversion of CO2 into valuable chemicals through electrochemical processes, specifically the electrochemical CO2 Reduction Reaction (CO2RR), thus aiding emission reduction and integrating renewable energy into global infrastructure. However, scaling this technology to industrial levels reveals significant hurdles. Achieving consistent reaction rates across the whole cell's surface area, optimizing current distribution, and addressing challenges related to CO2 mass transfer are critical considerations. Among these challenges, maintaining electrochemical performance over time emerges as the most important factor. Industrial-scale implementation is further complicated by the inherent complexity of operational modes, expanded surface areas, and intricate flow paths. Consequently, adopting a model-based approach becomes paramount. Leveraging computational models allows for comprehensive analysis and optimization of large-scale CO2 electrolysis systems, helping to understand system dynamics and to refine pivotal components such as gas diffusion electrodes. Advancing CO2 electrolyzer technology holds significant importance for both academic research and industrial applications in the pursuit of sustainable energy solutions [4,5]. In this study, we present a two-dimensional transient-state multiphase Gas Diffusion Electrode (GDE) model, which describes mass and heat transfer, electrochemical kinetics, aqueous-phase reactions, and species concentrations within the total flowing electrolyte volume in the system over time. Our study focuses on the conversion of CO2 to formate due to its industrial significance and commercial viability. We provide experimental validation of the model using results obtained from an industrial cell, specifically the first industrial 1526 cm² electrochemical cell. This represents a significant advancement, with a 60-fold increase from the largest three-compartment electrolyzer reported to date [6]. Subsequently, we apply the model to predict the scalability of the GDE and assess the impact of key parameters on system performance. We observe that electrolyzers with greater heights exhibit significantly stronger reactions at the same current density. Moreover, the model effectively captures the pH time dependency at various points in the GDE and aids in identifying the stability and evolution of the chemical species composing the GDE. It also accurately represents variations in carbonate and bicarbonate production, as well as the decrease of hydroxide over time in the catholyte. Furthermore, in the context of stability, we numerically investigate the impact of catalyst degradation over time on system performance. [1] Konderla, Vojtěch. "Numerical modelling of a gas diffusion-based CO2 electrolyser with flowing catholyte." (2022). [3] Kibria, Md Golam, et al. "Electrochemical CO2 reduction into chemical feedstocks: from mechanistic electrocatalysis models to system design." Advanced Materials 31.31 (2019): 1807166. [3] Smith, Wilson A., et al. "Pathways to industrial-scale fuel out of thin air from CO2 electrolysis." Joule 3.8 (2019): 1822-1834. [4] Yang, Ziming, et al. "Modeling and upscaling analysis of gas diffusion electrode-based electrochemical carbon dioxide reduction systems." ACS Sustainable Chemistry & Engineering 9.1 (2020): 351-361. [5] Gawel, A., et al., Electrochemical CO2 reduction-the macroscopic world of electrode design, reactor concepts & economic aspects. IScience, 2022. [6] Fink, A.G., et al., Scale‐up of Electrochemical Flow Cell towards Industrial CO2 Reduction to Potassium Formate. ChemCatChem: p. e202300977. Figure 1

Reactivity of 2-hydroxyethylhydrazinium nitrate (HEHN) with atomic iridium on graphite

In order to develop chemical kinetics models for the ignition and combustion of ionic liquid-based fuels, identification of the elementary steps in the thermal and catalytic decomposition of components such as 2-hydroxyethylhydrazinium nitrate (HEHN) is needed but is currently not well understood. The first decomposition step in protic ionic liquids such as HEHN is typically the proton transfer from the cation to the anion, resulting in the formation of 2-hydroxyethylhydrazine (HEH) and HNO3. In this investigation, temperature-programmed desorption mass spectrometry (TPD-MS) and x-ray photoelectron spectroscopy (XPS) are used to investigate the heterogeneous catalytic decomposition of HEHN with iridium. HEHN is introduced onto a highly-oriented pyrolytic graphite (HOPG) substrate (approx. 100 monolayers (ML)) and mass-selected iridium atoms (0–10 % ML) are deposited on the HOPG surface. The products can be identified by their masses, and product distributions are monitored as a function of surface temperature and Ir coverage. Formation of product species on the bare HOPG versus on the HOPG with increasing Ir coverage (5, 10 % Ir) indicates that the presence of iridium enhances various reactions. XPS confirms the presence of iridium on the surface and indicates the possible chemical bonding states involved. The products and their possible elementary reaction mechanisms are discussed.

Advancements in Understanding Beryllium Contamination: Novel Insights Into Environmental Risk Assessment

ABSTRACTBeryllium (Be), a lightweight metal with significant industrial applications, poses notable environmental and health risks due to its toxicity and persistence, and widespread use, particularly in the mechanical, aerospace, and electronics sectors. It is commonly alloyed with other heavy metals to enhance material properties. The primary environmental pathways for Be release include emissions from coal and fossil fuels combustion, as well as the incineration of solid wastes. Once introduced into the natural environment, primarily Be associated with soil particles and sediments, particularly in terrestrial and aquatic ecosystems. This review examined the pathways through which Be enters the environment, including atmospheric deposition, industrial discharge, and leaching from natural geologic deposits. The paper highlights the bioavailability and mobility of Be in soil and water systems, emphasizing the geochemical and physical factors influencing its persistence and potential for bioaccumulation. Risk appraisal methodologies are evaluated, with a focus on human exposure routes, including inhalation of airborne particulates and ingestion of contaminated water and food. The toxicological impacts on human health are critically analyzed, detailing both acute and chronic effects, such as respiratory diseases and carcinogenicity. This review evaluates existing regulatory frameworks and remediation strategies, assessing their efficacy in mitigating environmental contamination and exposure to Be. By integrating interdisciplinary research, this paper provides an in‐depth understanding of the environmental behavior and toxicology of beryllium, offering insights that can inform robust policy frameworks and shape future research directions.

Comprehensive approach to static firing tests of micro gas turbine engines powered by liquid fuels

The paper presents test results on the combustion of liquid fuels in micro gas turbine engines (MGTE). A setup was designed and built to determine the following MGTE characteristics: thrust, inlet static pressure, compressor static pressure, compressor total pressure, combustor total pressure, turbine total pressure, turbine speed, and the air temperature at the inlet, inside the compressor, at the turbine outlet, and at the nozzle exit. Thermodynamic cycle analysis of MGTEs was performed in the operation mode providing the required thrust. Noise and vibration levels of the MGTE operation were measured using a noise and vibration analyzer. Concentrations of anthropogenic emissions (CO, CO2, NO, NO2, N2O, SO2, CH4, C3H8) were recorded using a set of sensors. The tests revealed consistent patterns in the variation of throttle characteristics, gas composition, noise, and vibration in different engine operation modes. The test results were processed to produce plots of the key MGTE characteristics. Recommendations were developed for testing new types of fuels in MGTEs.

Exploring Hydrogen–Diesel Dual Fuel Combustion in a Light-Duty Engine: A Numerical Investigation

Dual fuel combustion has gained attention as a cost-effective solution for reducing the pollutant emissions of internal combustion engines. The typical approach is combining a conventional high-reactivity fossil fuel (diesel fuel) with a sustainable low-reactivity fuel, such as bio-methane, ethanol, or green hydrogen. The last one is particularly interesting, as in theory it produces only water and NOx when it burns. However, integrating hydrogen into stock diesel engines is far from trivial due to a number of theoretical and practical challenges, mainly related to the control of combustion at different loads and speeds. The use of 3D-CFD simulation, supported by experimental data, appears to be the most effective way to address these issues. This study investigates the hydrogen-diesel dual fuel concept implemented with minimum modifications in a light-duty diesel engine (2.8 L, 4-cylinder, direct injection with common rail), considering two operating points representing typical partial and full load conditions for a light commercial vehicle or an industrial engine. The numerical analysis explores the effects of progressively replacing diesel fuel with hydrogen, up to 80% of the total energy input. The goal is to assess how this substitution affects engine performance and combustion characteristics. The results show that a moderate hydrogen substitution improves brake thermal efficiency, while higher substitution rates present quite a severe challenge. To address these issues, the diesel fuel injection strategy is optimized under dual fuel operation. The research findings are promising, but they also indicate that further investigations are needed at high hydrogen substitution rates in order to exploit the potential of the concept.

Flame Speed Measurements of Ammonia–Hydrogen Mixtures for Gas-Turbines

Abstract Recent findings from the U.S. Energy Information Administration project an increase in domestic fossil fuel consumption (e.g., petroleum and natural gas) and global greenhouse gas emissions through 2050 (Nalley, S., 2021, “International Energy Outlook 2021 (IEO2021),” IEO2021 Release, CSIS, Center for Strategic and International Studies, Washington, DC, Technical Presentation, pp. 2–12). Consequently, advanced combustion research aims to identify fuels to mitigate fossil fuel consumption while minimizing exhaust emissions. Ammonia (NH3) is one of these candidates, as it has historically been shown to provide high energy potential and zero-carbon emission (CO and CO2) (Hayakawa, A., Goto, T., Mimoto, R., Arakawa, Y., Kudo, T., and Kobayashi, H., 2015, “Laminar Burning Velocity and Markstein Length of Ammonia/Air Premixed Flames at Various Pressures,” Fuel, 159, pp. 98–106). As a hydrogen (H2) carrier, NH3 serves as a possible solution to the U.S. Department of Energy's Hydrogen Program Plan by providing efficient H2 storage and conservation capabilities (U.S. Department of Energy, 2020, “Department of Energy Hydrogen Program Plan,” U.S. Department of Energy, Washington, DC, Report No. DOE/EE-2128). As a result, applied turbine-combustion research of NH3 and H2 fuel has been conducted to identify combustion performance parameters that aid in the design of sustainable turbomachinery (Chiong, M.-C., Chong, C., Ng, J., Mashruk, S., Chong, W., Samiran, N., Mong, G., and Medina, A., 2021, “Advancements of Combustion Technologies in the Ammonia-Fuelled Engines,” Energy Convers. Manage., 244, p. 114460). One of these key combustion parameters is the laminar burning speed (LBS). While abundant literature exists on the combustion of NH3 and H2 fuels, there is not sufficient evidence in high-pressure environments to provide a comprehensive understanding of NH3 and H2 combustion phenomena in turbine-combustor settings. To advance the state of the knowledge, NH3 and H2 mixtures were ignited in a spherical chamber across a range of equivalence ratios at 296 K and 5 atm to understand their flame characteristics and LBS which was determined using a multizone constant volume method. The experimental conditions were selected according to primary turbine-combustor conditions, as much research is needed to support NH3–H2 applicability in turbomachinery for power generation. The effect of H2 addition to NH3 fuel was observed by comparing the LBS for various NH3–H2 mixture compositions. Experimental results revealed increased LBS values for H2 enriched NH3, with the maximum LBS occurring at stoichiometry. The experimental data were accurately predicted by the University of Central Florida (UCF) NH3–H2 mechanism developed for this investigation, while NUI 1.1 simulations overestimated recorded LBS data by a significant margin. This study demonstrates and quantifies the enhancing effect of H2 addition to NH3 fuels via LBS and strengthens the literature surrounding NH3–H2 combustion reactions for future work.

Geolocation of Fixed Emission Sources Produced by Artisan Brick Kilns in the Atmospheric Basin of the City of Juliaca, Peru

Objective: The study objective is to investigate the application of georeferencing systems to identify the geospatial location of fixed sources of atmospheric emissions produced by artisanal brickyards in the air basin of Juliaca city-Peru. Theoretical Framework: Previous studies have shown that artisanal brickyards are a significant source of air pollution in developing urban and on the outskirts. Emissions of fine particles, nitrogen oxides and other pollutants from the burning of traditional fuels, such as firewood and coal contribute to the degradation of air quality and can have adverse effects on human health and the environment. The georeferencing application and geospatial analysis techniques in the atmospheric pollution study have allowed a better understanding of the spatial distribution of emission sources and their impact on the environment. These tools are essential to identify and map the artisanal brickyard locations and to evaluate their contribution to air pollution in urban and on the outskirts. Method: The methodology adopted for this research includes data collection and compilation of existing information; georeferencing of brickyards through the use of geographic information systems (GIS); analysis of geospatial data for the identification of spatial patterns; preparation of thematic and spatial distribution maps; and the interpretation of results. Results and Discussion: The study results highlight the importance of locating the fixed sources of emissions produced by artisanal brick factories in the Juliaca air basin. This precise spatial identification provides a solid basis for the formulation of policies and mitigation strategies aimed at reducing air pollution in the region, in addition to representing fundamental data for the use and exploitation of GIS for environmental protection and modelling, among others. Research Implications: The results can be applied or influence practices in the environmental and forestry engineering field, the ICTs application, modelling and simulation, and territorial planning, among others. Originality/Value: This study contributes to the literature using georeferencing techniques for environmental modelling purposes. The relevance and value of this research are evident in obtaining georeferenced points for the estimation of emission factors for the predictive calculation of volumes, flows and dispersion of pollutants in an air basin.

Application of thermodynamic equilibrium modelling to predict slagging and fouling tendencies of bituminous coal and wheat straw blends

The combustion or co-combustion of biomass or alternative fuels is important in the energy sector because of the need to reduce the share of fossil fuels. This article is a continuation of previous studies on the behaviour of the mineral matter of selected fuels during the sintering processes. The blends of wheat straw biomass from Polish crops (WS) with bituminous coal from the Makoszowa mine (BC) were studied. The study included proximate and ultimate analysis and oxide analysis of ash blends with the following composition: 10wt% WS/90wt%BC, 25wt% WS/75wt%BC and 50wt% WS/50wt%BC. Based on the oxide content, a prediction (using FactSage 8.0 software) of the sintering process of the mixtures tested. The following parameters were determined: slag phase content, specific heat at constant pressure, and ash density. The fracture stresses tests were carried out using the mechanical test. Pressure tests were also performed using the pressure drop test method. The test results of all test methods used were compared with each other. On the basis of this comparison, a clear correlation was found between the sintering temperatures determined by the mechanical method and the pressure drop method and the physical properties of the ashes, such as density and heat capacity, as well as the chemical properties, i.e. the content of the slag phase. The results of the presented research are a valuable addition to the previous work of the authors. The goal of this work is to develop a precise and measurably simple method to determine the sintering temperature of ashes. This is an extremely important issue, especially in the case of the need to use a wide range of fuels in the energy industry.

Numerical Study of Complex Heat Transfer and Aerodynamics in a Tube Furnace with a Flat Fuel Combustion Mode

The object of the study is a tubular furnace for steam reforming of natural gas. The channel walls are formed by a refractory lining and a tubular screen with a known temperature. The chamber volume is filled with a selectively radiating, absorbing and weakly scattering medium of gaseous fuel combustion products. The research method is based on the numerical solution of a system of two-dimensional integro-differential equations of radiative gas dynamics, closed by a two-parameter model of turbulent convection. It is shown that when burners are located on the side walls of the radiation chamber, a significant restructuring of the heat flux distribution occurs. A decrease in the chamber width is accompanied by an increase in both radiant and convective heat fluxes to the tubular screen.

Changes in properties of thermal insulations under certain environmental effects

AbstractSaving energy and reducing greenhouse gas emissions is a priority for the construction sector. Heating of buildings requires the burning of fossil fuels, which can be significantly reduced by insulating the building envelope. Nowadays, the thermal insulation of buildings is essential. There are several important, well-known data about most thermal insulation materials, but there is only negligible information about the change of their properties under installation conditions or if they are already exposed to additional stresses due to structural failures and damages. This study aimed to examine the changes in properties of three common thermal insulation materials when installed in a flat roof or facade and exposed to excess moisture due to the damage of waterproofing or façade and/or when exposed to direct strong sunlight.