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Emissions from internal combustion engines (ICEs) significantly impact the environment, leading continents worldwide to work towards reducing them. The industry is increasingly leaning towards electric powertrains. However, power plants still utilize ICEs as generators, contributing to global pollution. Consequently, ICE emissions are garnering international attention. Alternatives like the Homogeneous Charge Compression Ignition (HCCI) engine and biodiesel fuels are being explored. HCCI engines have not been extensively tested with Used Cooking Oil (UCO) biodiesel. This study investigates the performance and emissions of HCCI engines using UCO-based biodiesel. This study tested an air-cooled, single-cylinder, 4-stroke diesel engine operating at 3600 rpm with a displacement of 0.219 liters. The HCCI mode was activated during preheating and run at 2700 rpm under varying biodiesel blend percentages and intake temperatures. In HCCI mode, brake-specific fuel consumption (BSFC) increased, peaking at a 90°C intake temperature. Diesel fuel incylinder pressure reached a maximum of 81 bars at 90°C, decreasing to 79 bars at 70°C. The HCCI mode resulted in lower NOx, CO, and UHC emissions. Higher biodiesel blend ratios further reduced CO emissions. Raising the intake air temperature to 90°C lowered NOx emissions by 96.66%, from 150 ppm to 5 ppm. Using green energy sources as fuel in HCCI engines significantly reduced emissions in this study, suggesting their potential as a future fuel for advanced engines. [ABSTRACT FROM AUTHOR]

This article presents a novel approach to the analysis of heat release in a hydrogen-fueled internal combustion spark-ignition engine with exhaust gas recirculation (EGR). It also discusses aspects of thermodynamic analysis common to modeling and empirical analysis. This new approach concerns a novel method of calculating the specific heat ratio (cp/cv) and takes into account the reduction in the number of moles during combustion, which is characteristic of hydrogen combustion. This reduction in the number of moles was designated as a molar contraction. This is particularly crucial when calculating the average temperature during combustion. Subsequently, the outcomes of experimental tests, including the heat-release rate, the initial combustion phase (denoted CA0-10) and the main combustion phase (CA10-90), are presented. Furthermore, the impact of exhaust gas recirculation on the combustion process in the engine is also discussed. The efficacy of the proposed measures was validated by analyzing the heat-release rate and calculating the mean combustion temperature in the engine. The application of EGR in the range 0-40% resulted in a notable prolongation of both the initial and main combustion phases, which consequently influenced the mean combustion temperature. [ABSTRACT FROM AUTHOR]

This research aimed to analyze the possibility of installing an ultrasonic emitter in an already manufactured car and to prove the possibility of cleaning the exhaust gases of an internal combustion engine through the action of an ultrasonic wave due to coagulation and examining the optimal regimes of its work. The existing theoretical solution to describe the proposed process was analyzed. A Mercedes-Benz M-Class ML 270 CDI MT car with the OM 612 DE 27 LA Diesel engine was used for the experiment. An ultrasound generator and an ultrasound emitter were connected to the muffler. The stand was connected to the car via the inlet with a rubber hose that directs the exhaust gases out of the car. The crankshaft speed of the engine was changed in the range of 750 to 1250 rpm, which corresponds to urban conditions when cars are moving in heavy traffic jams. The content of CH, CO, CO2, and O2 in the exhaust gas of the vehicle was determined as a function of the crankshaft speed without ultrasonic exposure and with ultrasonic exposure at an ultrasound frequency of 25, 28, and 40 kHz. The results of the experiment showed that the introduction of an ultrasonic emitter into the muffler reduced the smoke content of the gas, increased the oxygen content, and reduced the amount of carbon dioxide in the exhaust gases. With an increase in the ratio between the ultrasonic frequency and the angular velocity of the engine crankshaft (f/ω), the smoke content of the gas also decreased. At the maximum values of ultrasonic frequency and angular velocity of the engine crankshaft selected in the experimental studies, the minimum value of the ratio of gas smoke indicators was achieved, and the degree of purification was 10–13%. Such results correspond to the condition of optimal operation of the ultrasonic muffler, where the ratio of gas to smoke values should tend to a minimum. These results confirm the potential of using ultrasound as a method for cleaning exhaust gases and underline the need for further research in this area. [ABSTRACT FROM AUTHOR]

Fuel injection systems significantly impact the combustion process and play a key role in reducing harmful exhaust emissions in internal combustion engines. For dual-fuel (DF) engines operating in gas mode, ignition of the main fuel is typically controlled by directly injected liquid pilot fuel. Liquid pilot fuel's initial penetration and total mass considerably impact exhaust emissions and combustion stability. We investigated the spray morphology of a multi-hole diesel fuel injector within a constant-volume spray chamber using high-speed shadowgraphy and Mie-scattering measurements. Two methodologies were employed. The first one utilized a nozzle equipped with a thimble structure to isolate a single plume. The second methodology known as plume-blocking, involved sealing the orifices of the multi-hole nozzle to generate a single-spray plume. Our findings revealed that the plume-blocking approach demonstrated greater penetration than the thimble-equipped nozzle. The rapid penetration of this method may restrict its applicability to single-spray studies. Sprays generated from this partially sealed nozzle exhibited noticeable disparities compared to an unblocked nozzle, whereas a nozzle equipped with a thimble produced similar outcomes to the standard nozzle. The orifices when sealed, modify the flow distribution within the sac volume, which consequently affects the spray characteristics. In summary, this research provides insights into the impacts of various plume isolation methods on spray morphology, thereby enhancing the understanding of spray behaviour in transient conditions by comparing plume variations and disturbances under various fuel pressure and ambient conditions. [ABSTRACT FROM AUTHOR]

Waste heat recovery from exhaust gas is one of the most convenient methods to save energy in internal combustion engine-driven vehicles. This paper aims to investigate a reduction in waste heat from the exhaust gas of an internal combustion engine of a serial Diesel–electric hybrid bus by recovering part of the heat and converting it into useful power with the help of a split-flow supercritical CO2 (sCO2) recompression Brayton cycle. It can recover 17.01 kW of the total 33.47 kW of waste heat contained in exhaust gas from a 151 kW internal combustion engine. The thermal efficiency of the cycle is 38.51%, and the net power of the cycle is 6.55 kW. The variation in the sCO2 temperature at the shutdown of the internal combustion engine is analyzed, and a slow drop followed by a sudden and then a slow drop is observed. After 80 s from stopping the engine, the temperature drops by (23–33)% depending on the tube thickness of the recovery heat exchanger. The performances (net power, thermal efficiency, and waste heat recovery efficiency) of the split-flow sCO2 recompression Brayton cycle are clearly superior to those of the steam Rankine cycle and the organic Rankine cycle (ORC) with cyclopentane as a working fluid. [ABSTRACT FROM AUTHOR]

Internal combustion engines produce about 10% of the world's greenhouse gas emissions. Electric vehicles generate 17-30% lower emissions than the internal combustion engines. However, the formers entail certain drawbacks, namely the few available charging stations, the high charging cost, and the limited battery life. The purpose of this paper is to propose the best suitable converter for the on-board charger, which will be able to decrease the charging cost by improving the power factor and the battery life span. This enhancement will be accomplished through the reduction of the charging current either at a very high or very low State of Charge (SOC). Isolated and non-isolated converter topologies were studied to identify the most suitable converter for the on-board charger that will be able to ameliorate the efficiency and the input power factor as well as control the charging current limits. A non-isolated buck converter with switched inductors is used for the power factor adjustment along with the current control approach to achieve a highly efficient on-board charger. Compared to the isolated converter with transformers, the non-isolated hybrid switched inductor buck converter has a wider current control range. MATLAB/Simulink output results were analyzed to validate the performance of the designed on-board charger with a non-isolated converter. [ABSTRACT FROM AUTHOR]

Three-way catalysts (TWCs) are widely used in vehicles to convert the exhaust emissions from internal combustion engines into less toxic pollutants. After around 8–10 years of use, the declining catalytic activity of TWCs causes them to need replacing, leading to the generation of substantial amounts of spent TWC material containing precious metals, including palladium. It has previously been reported that [NnBu4]2[Pd2I6] is obtained in high yield and purity from model TWC material using a simple, inexpensive and mild reaction based on tetrabutylammonium iodide in the presence of iodine. In this contribution, it is shown that, through a simple ligand exchange reaction, this dimeric recovery complex can be converted into PdI2(dppf) (dppf = 1,1′-bis(diphenylphosphino)ferrocene), which is a direct analogue of a commonly used catalyst, PdCl2(dppf). [NnBu4]2[Pd2I6] displayed high catalytic activity in the oxidative functionalisation of benzo[h]quinoline to 10-alkoxybenzo[h]quinoline and 8-methylquinoline to 8-(methoxymethyl)quinoline in the presence of an oxidant, PhI(OAc)2. Near-quantitative conversions to the desired product were obtained using a catalyst recovered from waste under milder conditions (50 °C, 1–2 mol% Pd loading) and shorter reaction times (2 h) than those typically used in the literature. The [NnBu4]2[Pd2I6] catalyst could also be recovered and re-used multiple times after the reaction, providing additional sustainability benefits. Both [NnBu4]2[Pd2I6] and PdI2(dppf) were also found to be active in Buchwald–Hartwig amination reactions, and their performance was optimised through a Design of Experiments (DoE) study. The optimised conditions for this waste-derived palladium catalyst (1–2 mol% Pd loading, 3–6 mol% of dppf) in a bioderived solvent, cyclopentyl methyl ether (CPME), offer a more sustainable approach to C-N bond formation than comparable amination protocols. [ABSTRACT FROM AUTHOR]

In recent years, biofuels have gained considerable prominence in response to growing concerns about resource scarcity and environmental pollution. Previous investigations have revealed that the appropriate blending of iso-propanol–butanol–ethanol (IBE) into diesel significantly improves both the c combustion efficiency and emission performance of internal combustion engines (ICEs). However, the combustion mechanism of IBE–diesel for the numerical studies of engines has not reached maturity. In this study, a skeletal IBE–diesel multi-component mechanism, comprising 157 species and 603 reactions, was constructed using the decoupling method. It was formulated by amalgamating the reduced fuel-related sub-mechanisms derived from diesel surrogates (n-dodecane, iso-cetane, iso-octane, toluene, and decalin) and n-butanol, along with the detailed core sub-mechanisms of C1, C2, C3, CO, and H2. The constructed mechanism is capable of better matching the physical and chemical properties of actual diesel fuel. Extensive validation, including ignition delay, laminar flame speed, a premixed flame species profile, and engine experimental data, confirms the reliability of the mechanism in engine numerical studies. Subsequent investigations reveal that as the IBE blend ratio and EGR rate increase, the ignition delay exhibits an increase, while the combustion duration experiences a decrease. Blending IBE into diesel, along with a specific EGR rate, proves effective in simultaneously reducing NOx and soot emissions. [ABSTRACT FROM AUTHOR]

Hydrogen may become a substitute for liquid fossil fuels, contributing to greenhouse gas emissions reductions in internal combustion engines. Numerical simulations play a critical role in the advancement of these engines, with laminar flame speed being the main input. Experimental data of hydrogen flame speed at elevated pressures are scarce, due to the instability of the flames. Nonetheless, stable hydrogen flames can be predicted using chemical kinetics models. Moreover, the injection of water into the hydrogen fuelled engine could offer several benefits to engine combustion and emission performance, as it modulates the laminar flame speed within the combustion chamber and this effect has not been completely understood. Currently, no correlation exists to predict the laminar flame speed of hydrogen-air combustion with water addition under lean mixture engine operating conditions. In this study, we have extended the newly developed laminar flame speed correlation of hydrogen-air combustion to account for the effects of water addition under engine relevant conditions by using chemical kinetic laminar flame speed values. The laminar flame speed correlation was derived for pressures from 10 to 70 bar, temperatures from 400 to 800 K, equivalence ratios from 0.35 to 1 and water addition by mole from 0 to 20%. The hydrogen laminar flame speed correlation was expressed using polynomial forms with reduced order and number of terms with optimized values of coefficients. Additionally, a new exponential term was proposed to the power term α of the laminar flame speed correlation to capture the coupled effects of pressure and temperature on laminar flame speeds under engine-relevant lean burn water-diluted operating conditions. • Water injection with hydrogen offers benefits for combustion and emission performance. • New correlation for predicting flame speed of hydrogen combustion with water addition. • Hydrogen laminar flame speed under engine relevant conditions using chemical kinetics. • New Hydrogen laminar flame speed correlations using reduced order polynomial form. • New term proposed to capture the coupled effects of pressure and temperature. [ABSTRACT FROM AUTHOR]

The object of research is the environmental parameters of a reciprocating engine when using a synthesis gas additive to the main fuel. The research is aimed at solving the problem of reducing the concentration of harmful components in the exhaust gases of an internal combustion engine by adding synthesis gas to the main fuel. Experimentally, the dependences of the effect of the addition of synthesis gas to ethanol on the change in the environmental performance of a piston engine with spark ignition were obtained. The positive effect of the addition of synthesis gas obtained by thermochemical conversion to ethanol in an amount of up to 5 % by weight on the environmental performance of a spark-ignition piston engine was established. Provided that the engine achieves the same effective power, the use of a synthesis gas additive to the main fuel made it possible to reduce the concentration of CO by 61.5 % and CH by 51.3 % in the exhaust gases. no more than 25–30 words The addition of synthesis gas contributed to the formation of radicals that activate oxidation chain reactions, and also made it possible to increase the normal combustion rate of the fuel-air mixture by 6.25 %. This ensures normal engine operation on a leaner fuel-air mixture (α=1.21) without deterioration of environmental, energy and economic performance. no more than 25-30 words The simultaneous reduction of the concentration of harmful components in the exhaust gases and engine efficiency can be achieved by using fuels with a wide concentration limit of ignition and high combustion rate in a lean mixture. The experimental data obtained can be used in the design or modernization of transport and stationary power plants with internal combustion engines as an approach to meet ever-increasing environmental standards. [ABSTRACT FROM AUTHOR]

In this article, the construction principle of rotary engine and sliding vane internal combustion engine is carefully analyzed, and the concept of micro‐rotary cam internal combustion engine is proposed by integrating and innovating on them. Overall design, theoretical analysis, and model making of miniature rotary cam internal combustion engine and its supporting system. The effects of different air intake modes and different ignition advance angles on the combustion and emission characteristics of internal combustion engines were studied. Through the study of the flow field, combustion and emission characteristics of small rotating internal combustion engines, it is found that the intake form has a great influence on the cylinder smoothness of rotating internal combustion engines. The vortex formed by the end cover inlet air in the middle of the combustion chamber can fully mix the fuel and air in the cylinder, and the mixture is evenly distributed in the combustion chamber to effectively promote the spread of flame. Compared with the surrounding air intake structure, the heat release should be increased by 4.3%, and the total amount of HC and CO generated was 26.8% and 15.7% less, respectively. By studying the turbulent kinetic energy, combustion heat release, peak temperature and pressure in the cylinder, fuel consumption rate and emission characteristics of small rotary internal combustion engine, it is found that when the ignition advance angle of the small rotating internal combustion engine is 5°, the peak pressure in the cylinder is increased by 2.3% compared with other schemes, the fuel consumption rate is high, and the combustion is more complete. In addition, in terms of emission characteristics, the amount of CO and HC generated when the ignition advance angle is 5° are reduced by 35% and 35.3%, respectively. [ABSTRACT FROM AUTHOR]

Electric vehicles (EVs) are crucial in mitigating global emissions by replacing internal combustion engines. The capacity of EV batteries, coupled with their charging infrastructure, offers the added advantage of supplying flexible demand capacity and providing demand response benefits to the power grid, which is essential as overall demand increases. EVs ready for vehicle-to-everything (V2X) applications and chargers that support them enhance this flexibility by allowing for varied storage applications. However, to fully harness these benefits, it is vital to consider EV drivers' charging habits and optimize the charging and discharging controls to minimize battery life impact. This study examines various V2X applications in North America and their effects on battery longevity, considering EV charging patterns. Additionally, it investigates advanced aging-aware optimization algorithms for managing bidirectional charging. [ABSTRACT FROM AUTHOR]

Energy is a fundamental necessity for man›s life in the digital world today. The rapid depletion of fossil fuel resources forces rigorous alternative fuel analysis. Petroleum diesel can better replace vegetable oils, edible or motored today. The rapid depletion of fossil fuel resources forces rigorous alternative fuel analysis. Petroleum diesel can better replace vegetable oils, edible or not. Karanja may be a possible supplier of diesel fuel for non-edible oil substitution. Current combustion surfaces for pistons, valves, and cylinders have been filled with ceramic materials, which make the engine totally adiabatic (LHR). The performance of a biodiesel-powered compressing ignition (CI) engine may be further boosted by utilising the engine›s heat effectively and increasing thermal efficiency. Exhaust Gas Recirculation (EGR) is actually one of the most important methods of limiting NOx emissions in internal combustion engines. Explore the output with and without exhaust gas recirculation on a retarded timing engine with diesel and karanja oil methyl ester (KOME). The LHR with a retarded timing engine yielded improved thermal brake efficiency (TBE), decreased HC, smoke, and CO emissions, while increasing KOME›s NOx in comparison with an uncoated engine. As the EGR rate grew, NOx and BTE were reduced marginally with increased HC, CO, and smoke. 24.1 g/kw-hour CO, 10.1 g/kw-hour NOx, and 0.55 g/kW-hour HC were registered at 20 percent of EGR. [ABSTRACT FROM AUTHOR]

This article titled "Heavy-Duty Transportation in 10 Charts" by Ahmet Kusoglu discusses the significance of freight movement in the transportation industry and its economic implications. It emphasizes that heavy-duty trucking is responsible for the majority of cargo transportation in the United States, carrying 72% of freight in terms of value and two-thirds in terms of weight. However, heavy-duty trucks also contribute significantly to energy consumption, greenhouse gas emissions, and air pollution. The article highlights the importance of reducing the environmental impact of heavy-duty trucks to protect public health, especially in underserved communities. It discusses the disparities in PM2.5 concentration among different economies and the negative health effects of these emissions. The article stresses the need to eliminate harmful pollutants from vehicle combustion, particularly heavy-duty trucks, in order to decarbonize the transportation sector. It also acknowledges the challenge of reducing emissions in the trucking industry, given the higher per-vehicle emissions from heavy trucks compared to passenger cars. The article concludes by emphasizing the importance of decarbonization in reducing emissions and the need for further analysis of the transportation sector, specifically heavy-duty trucks and freight movement. [Extracted from the article]

With the stricter emission regulations for internal combustion engines, electric vehicles, including electrically powered port tractors, have received increasing attention. However, currently, most of the filters used in electric vehicles are conventional membranes that only have the function of filtering particles and foreign objects. Therefore, in order to improve the above issues, the surface of commercial non-woven filter membranes was coated with Ag nanopowder nanofibers and AgNO3 nanofibers via electrospinning. At present, the comparative research on the antibacterial ability of Ag nanopowder and AgNO3 is still blank in the same research system, especially with the use of electrospun coating technology. The morphologies and structures of non-woven fabrics and electrospinning coated samples were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The characterization results indicate that both pure PVA and PVA composite fibers can be successfully coated on the surface of non-woven fabrics. The average diameter of all electrospun PVA composite fibers is distributed in the range of 470–700 nm. The PVA nanofibers with a low content of 1 wt% AgNO3 have good antibacterial properties against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), with clearance clear zones of inhibition of 26.00 mm and 17.30 mm, respectively. [ABSTRACT FROM AUTHOR]

In the light of the recent standards proposed by the European Union in terms of CO 2 emissions for the internal combustion engines, the attention is increasingly focused on e-fuels, among which the renewable-produced hydrogen. The present paper proposes a numerical methodology for 3D-CFD in-cylinder simulations of hydrogen-fuelled internal combustion engines. The proposed framework includes in-house developed models for ignition, knock and heat transfer and it is based on the G-equation combustion model. The predictive capabilities of the methodology are validated against experimental data on a single-cylinder naturally-aspirated diesel engine converted for spark-ignited hydrogen operation. Specifically, H 2 is direct injected thanks to two injectors installed on the cylinder head. Moreover, a spark plug is added and the compression ratio is lowered. The investigated conditions cover different revving speeds (from 1500 rpm to 3000 rpm) and equivalence ratios (0.4, 0.6 and 0.8). The satisfying agreement between numerical results and experimental counterparts paves the way to future studies (e.g. on emission modelling) and engine optimization. • Simplification of geometry of injectors preserved the accuracy of the results. • Mixture homogeneity in swirling flow field is influenced by injected amount of fuel. • Flamelet combustion model G equation is reliable for engine combustion simulation. • Wide range of operating conditions can be simulated with same numerical setup. [ABSTRACT FROM AUTHOR]

The addition of renewable fuel to hydrocarbon fuel mitigated the carbon monoxide, carbon dioxide and soot particle emissions of internal combustion engines. A comparative study of the ammonia and hydrogen effect on combustion and emission characteristics of n-hexadecane flames was executed at various flame conditions. The results showed that alternative fuels had a stronger impact on peak temperature at diffusion flame conditions rather than at premixed flame conditions. The premixed flame released carbon monoxide emission lower than the diffusion flames with/without additional fuels. The carbon monoxide emissions decreased highly with ammonia enrichment instead of hydrogen. At premixed and coflow diffusion flame conditions, the ammonia highly reduced carbon dioxide emission compared to hydrogen. Hydrogen addition reduced the nitrogen oxide emission, whereas it was increased by ammonia. The soot particle number density was reduced highly by hydrogen addition instead of ammonia at the premixed flow flame and diffusion coflow flame conditions. The impact of hydrogen on the reduction of soot mass concentration emissions was greater than that of ammonia at all combustion conditions. It is suggested that H 2 ≥ 70% should be mixed in n-hexadecane fuel because a higher burning velocity can be achieved with a higher emission reduction. A reduction in the emission of carbon-related species can be realized with a small reduction in burning velocity at NH 3 < 70%. • Comparative study of H 2 and NH 3 impact on n-Hexadecane flame. • Premixed flow flame and diffusion counterflow and coflow flames studied. • Combustion species along with PAH and NOx species were discussed. • Soot surface equations along with Moss-Brookes model were used. • Results suggest H 2 ≥ 70% and NH 3 ≤ 70% should be used in n-Hexadecane fuel. [ABSTRACT FROM AUTHOR]

This document provides a summary of various research articles related to biodiesel production, engine performance, and emissions. The articles cover topics such as the synthesis of biodiesel from turpentine tree oil, the effects of acetone as a fuel additive in diesel engines, and the impact of different biodiesel blends on combustion and emissions. The studies highlight the complex interactions between biodiesel, diesel fuel, and additives, and emphasize the need for further research to improve fuel and engine efficiencies. The articles also discuss the potential of biodiesel technology in reducing environmental impact. [Extracted from the article]

Polyoxymethylene dimethyl ether (PODE) and methanol are important low-carbon substitutable fuels for reducing carbon emissions in internal combustion engines. In the research, the impacts of methanol ratio, injection timing, and intake temperature on HCHO generation and emission were investigated using both engine tests and numerical simulations. Results suggest that an increase in methanol ratio suppresses auto-ignition tendency of PODE, leading to the increase of ignition delay period, pressure peak, and heat release rate peak inside the cylinder. The decrease in in-cylinder combustion temperature contributes to an increase in HCHO emission due to partial oxidation of methanol in the cylinder and exhaust pipe. While the injection timing is gradually postponed from −10 °CA ATDC to 2 °CA ATDC, in-cylinder high-temperature area decreases, the quantity of unburned methanol increases, but part of HCHO is converted to HCO due to H radical influence, resulting in 72% increased HCHO emission. With the increment of intake temperature, the oxidation and decomposition of in-cylinder methanol accelerate, leading to an improvement in combustion stability, more uniform temperature distribution, and a decrease in unburned methanol, which results in lower HCHO emission. When the intake temperature is rose from 30 to 60 °C, HCHO emission decreases by 11.2%. [ABSTRACT FROM AUTHOR]

In toxic substance detection devices based on ion mobility spectrometry with atmospheric pressure chemical ionization, hydrated ammonium (H2O)n is increasingly used as a reagent ion instead of the commonly used hydrated hydroxonium H3O+(H2O)n ion and ions preceding and accompanying its formation. The use of hydrated ammonium makes it possible to increase the specificity of devices in the presence of such problematic interferences as exhaust gases of internal combustion engines and motor fuel vapors. In this paper, the mechanism of increasing specificity in the presence of alkanes, significantly predominant in these interferences, is justified. In the absence of ammonia, which is used to produce hydrated ammonium, the chemical ionization of alkanes occurs as a result of fast exergonic reactions with ions preceding ( , , , H2O+ , and H3O+) and accompanying (NO+ and NO+(H2O)) the formation of hydrated hydroxonium. When ammonia is added, these ions react with it and are almost completely consumed in fast exergonic reactions. Thereby ammonia suppresses the chemical ionization of alkanes by precursor and accompanying ions. The direct chemical ionization of alkanes with the help of hydrated ammonium does not occur due to the endergonicity of the reactions and the almost complete shift of their equilibrium towards the formation of the initial reagents. As a result, the devices do not give false-positive signals when exposed to alkanes. In addition, the devices do not produce false-negative signals when analytes are detected in a mixture with alkanes, since hydrated ammonium is practically not consumed in reactions with alkanes. [ABSTRACT FROM AUTHOR]

The global proportion of eco-friendly vehicles continues to increase; however, regarding hybrid vehicles, the vehicle powertrains in most countries include internal combustion engines. Therefore, research on reducing the carbon emissions from internal combustion engines must be conducted. Carbon capture technology must be developed for e-fuel, which has recently attracted attention, to achieve carbon neutrality. In this study, a turbo compound system capable of recovering waste exhaust gas energy was selected as the most appropriate energy supply system to operate a mobile carbon capture system. The feasibility was reviewed by analyzing the turbo compound speed, pressure drop, power generation, etc., using a one-dimensional simulation method. The maximum power generation of the configured turbo compound system was approximately 9 kW, and approximately 1–3 kW of energy could be recovered under medium speed and load conditions, which are the optimal operating conditions for a test engine with the displacement of a 4 L. [ABSTRACT FROM AUTHOR]

Biodiesel is regarded as a clean fuel alternative to fossil diesel fuel for fewer pollutant emissions of internal combustion engines. The biodiesel type can be made from waste frying oil, thus it has to be done right. Waste vegetable oil can be provided for free or at a low cost by restaurants and food processors that often use frying oils. Animal fat is also available for free or for a nominal fee from grocery stores, restaurants, and butchers who use lots of fats in their cooking. The methyl ester of oleic acid methyl ester (OAME) biodiesel was produced from used vegetable oil using the transesterification process in order to compare the performance of the 67 kW KUBOTA tractor diesel engine when utilizing OAME and fossil diesel. OAME biofuel was used without being mixed. The engine's reliability metrics and important indicators, including the brake torque, indicated power, brake-specific fuel consumption (BSFC) and burn duration, were identified. Optimal implementation was met by fossil diesel and the tested characteristics were very close. The OAME biofuel performs better in terms of volumetric efficiency and duration of combustion than the conventional diesel. The decision to choose a specific biofuel that is produced from a particular source so largely hinges on its availability and economic feasibility wherever it is used. [ABSTRACT FROM AUTHOR]

Although their ease of transport, storage, and use makes hydrocarbon fuels dominant in commercial energy systems, the emission of harmful gases, including greenhouse gases, is a fatal disadvantage. Despite ongoing research to improve thermal efficiency and reduce the emissions of internal combustion engines using conventional hydrocarbon fuels, achieving net-zero carbon requires decarbonizing fuels rather than reducing the use of internal combustion engines. Hence, transitioning away from hydrocarbon fuels and evolving internal combustion engines into clean engines using carbon-free fuels, such as hydrogen, is necessary. This study designs a 2.0 L research engine and numerically analyzes its combustion characteristics and spray behavior by varying the spray angle and equivalence ratio. When comparing the turbulence kinetic energy at a 45-degree spray angle with that at 30 degrees and 60 degrees, on average, there was a difference of approximately 37.54 m2/s2 and 26.21 m2/s2, respectively. However, misfires occur in the lean condition. Although hydrogen has a wide flammability range, poor mixture formation under lean conditions can result in misfires. The 60-degree spray angle resulted in the highest combustion temperatures and pressures for all equivalence ratio conditions, consequently leading to the highest emissions of nitrogen oxides. Specifically, at a lambda value of 2.5, the 60-degree spray angle emitted approximately 29 ppm, 0 ppm, and 161 ppm of nitrogen oxides for each respective spray angle. [ABSTRACT FROM AUTHOR]

Currently, modern internal combustion engines are receiving great attention due to their efficiency, particularly in response to the increasing limits imposed by environmental and emission legislation. Sound emissions of internal combustion engines are mainly caused by three sources of noise: combustion, mechanical and aerodynamic flow. The secondary motion of the piston plays a crucial role in the analysis of performance, noise, vibration and reliability of internal combustion engine (ICE). In the presented article, a mathematical simulation model has been developed by using of the GT-Suite software to study the rotational and lateral motion of the piston (called secondary motion) as well as the piston slap in ICE. This model takes into account the effect of variation in the major geometric parameters of the skirt design, such as the piston pin offset (P.P.O) and the length of the skirt. Furthermore, a combined model that accounts for the interplay between the secondary dynamics of the piston and the dynamic fluid lubrication has been developed. This model utilizes a mixed lubrication approach for the purpose of simulation. The results of this simulation have demonstrated that the variations in length of the skirt and the P.P.O have a considerable effect on piston secondary motion and tribological performances, and that the lateral motion of the piston is significantly influenced by the piston side force, which plays a crucial role in this behavior. [ABSTRACT FROM AUTHOR]

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

Exergy is a thermodynamic concept that ponders the quality of energy. It evaluates the irreversibilities of a machine, demonstrating its capacity to perform work associated with energy conversion. This article focuses on directing public policies and vehicle development toward their most proper usage worldwide. In the urban mobility scenario, there is an obvious demand to decrease greenhouse gas (GHG) emissions. In addition, the internal combustion engine (ICE) experiences considerable energy losses through heat exchange through the radiator and exhaust flow gases, which are not considerable in battery electric vehicles (BEVs) since there are no exhaust gases subsequent to combustion, nor combustion itself. This work presents longitudinal dynamics simulations of passenger vehicles to understand the magnitude of exergy destruction in ICEVs and BEVs, considering the Brazilian and European Union electric energy mix. Overall, the method can be applied to any other country. The simulation and model parameters were configured to match production road vehicles commercialized in the Brazilian market based on different versions of the same model. Two vehicle dynamic duty cycles were used, one relating to urban usage and another to highway usage, resulting in an overall exergy efficiency of around 50–51% for BEVs considering the exergy destruction in power plants. In contrast, ICE has an average efficiency of 20% in the urban cycle and around 30% in the highway cycle. By comparing the overall equivalent CO2 emissions, it is possible to conclude that EVs in the European energy matrix produce more GHG than ICE vehicles running on ethanol in Brazil. Nevertheless, there are increasing uses of coal, natural gas, and oil thermal electric power plants, raising the question of how the transition may occur with a general increase in electrification since there is an increasing electric expenditure in all sectors of society, and the renewable energy plants may not meet all of the demand. [ABSTRACT FROM AUTHOR]

In recent years, there has been a rapid transition from internal combustion engines to hybrid and electric vehicles. It is an inevitable fact that the dominance of internal combustion engines in the market will continue for many years due to the charging and battery problems in these vehicles. Therefore, it is an important issue to improve the performance and emissions of internal combustion engines by making them work with alternative energy sources. In this study, hydrogen-diesel dual fuel mode was used in a dual-fuel compression ignition single cylinder engine with common rail fuel injection system and electronically controlled gas fuel system. The study was carried out at constant speed (1850 rpm), different load (3-4.5-6-7.5-9 Nm) and different hydrogen injector opening amounts (1.6-1.8-2.0 ms). The effects of hydrogen energy ratios obtained with different hydrogen injector opening amount on engine performance and emissions were examined. According to the results, it was determined that the in-cylinder pressure values increased at medium and high loads, and the specific energy consumption decreased. When the emission values were examined, it was determined that there was an increase in NO emissions and a significant decrease in other emissions. However, increasing the hydrogen energy ratio above 14% adversely affected engine performance and emissions. Schematic view of the experimental setup. [Display omitted] • In dual fuel mode, fuel systems must be electronically controlled. • Hydrogen energy rate up to 14%, positively affects performance and emissions. • In hydrogen-diesel dual fuel mode, all emissions are reduced except NO emissions. • Dual fuel mode increases cylinder pressure, reduces fuel consumption. [ABSTRACT FROM AUTHOR]

Zero carbon fuels can be used to reduce CO 2 emissions from internal combustion engines. Hydrogen is an important zero-carbon fuel that can be used as the primary fuel for spark ignition (SI) engines or in dual-fuel operation in compression ignition (CI) engines. The combustion properties of hydrogen often result in high combustion temperature which produces harmful nitrogen oxides (NO x) emissions. To reduce NO x and soot emissions from hydrogen fueled engines, an engine can be optimized using a hardware-in-the-loop (HIL) setup to reduce calibration efforts for the engine. In addition, optimal model based combustion control (MCC) can reduce engine-out emissions. Both of HIL and MCC techniques require fast and accurate NO x and soot emission models. The accuracy of a fast physics-based engine model with pre-mixed combustion is dependent on predicting the laminar flame speed (LFS). In this study, LFS is predicted using an artificial neural network (ANN) machine learning (ML) method. Then the LFS model and engine combustion model are validated for both an SI hydrogen engine and for a CI hydrogen-diesel engine. Next, black-box and gray-box soot and NO x emission models are developed for the hydrogen-diesel engine using ANN, support vector machine (SVM) and Gaussian process regression (GPR) methods with different feature-sets and compared with the a common one-dimensional physics-based NO x model. The developed gray-box emission models can predict NO x and soot emissions with an R test 2 value of higher than 0.99 which makes them suitable for engine HIL setups where accuracy is very important. On the other hand, the black-box emission models can predict NO x and soot emissions with R test 2 value higher than 0.95 with a run time thousands of times faster than the gray-box models. This makes the black-box models suitable for model-based real time hydrogen combustion control where limited computational power is available. • Model to predict combustion and performance of single and dual fuel hydrogen engines. • Gray box model to Predict NOx and soot emission of hydrogen engine with R2 test > 0.99. • Physical hydrogen engine models using embedded machine learning laminar flame speed. • Systematic machine learning method and input feature set study for emission models. • Experimental data for spark and compression ignition hydrogen fueled engines. [ABSTRACT FROM AUTHOR]

The main goal of the contemporary automotive industry is to improve efficiency and reduce harmful emissions of internal combustion engines. Approximately 25% of the total mechanical losses in engines are attributed to friction in the piston rings.Therefore, in all modern engines, a twin land oil control ring (TLOCR) is used due to its affordable cost and satisfactory performance in oil regulation under low workload conditions. In this work, a model for the oil control ring (TLOCR) was proposed, which takes into account ring elastic deformation. The TLOCR model was used to evaluate friction produced in piston ring assembly and the results were compared to the experiment data obtained from a single cylinder diesel engine. The model was based on correlation between the lubricating oil pressure and oil film thickness developed. The behavior of lubricant oil was investigated for different engine operational conditions and different tensions in the rings. Both experimental and numerical modeling data showed a good match, thereby validating the proposed model [ABSTRACT FROM AUTHOR]

A method of purification and utilization of internal combustion engine exhaust gases, due to the ultrasound impact on gases in a special storage tank, has been proposed. Large soot particles of gases due to coagulation are deposited on the bottom of the device and disposed of. The hypothesis of analogy of the gas concentration law and the ratio of soot particles during coagulation has been proven. The soot coagulation coefficient has been determined theoretically and experimentally. An experimental bench has been developed. The technique of assessing coagulation processes by the degree of gas transparency before and after exposure to ultrasound has been developed and used, as well as the technique of calculating equipment and options for designing the devices for ultrasonic purification of exhaust gases. [ABSTRACT FROM AUTHOR]

To further improve air quality in China, especially ozone and fine particulate matter (PM2.5), additional reductions of volatile organic compounds (VOCs) are needed. Evaporative emissions from internal combustion engines (ICE) and hybrid vehicles are known to be an important source of VOCs in urban cities, which can be efficiently reduced through the introduction of more stringent regulatory standards. The most stringent global standards for evaporative emissions are the U.S. Tier 3 light-duty vehicle standards. This study compares the evaporative emissions of light-duty ICE vehicles designed to China 6 and U.S. Tier 3 regulations for both China and U.S. test conditions. Data are analyzed from manufacturer testing of full vehicle evaporative emissions conducted in the laboratory following U.S. Tier 3 and China 6 certification test methods utilizing Sealed Housing for Evaporative Determination (SHED) chambers equipped with Flame Ionization Detection (FID) analyzers. Vehicles designed to U.S. Tier 3 standards are observed to have 64% lower diurnal and hot soak evaporative emissions and 98% lower canister bleed emissions relative to vehicles designed to China 6 standards. U.S. Tier 3, U.S. Tier 2, and China 6 light-duty evaporative emission certification values submitted by manufacturers are also compared. The average of all current U.S. Tier 3 certifications is, on average, 52.4% lower than the average of all China 6 certifications. The results from the testing and data analysis of five vehicles, with comparison to the certification data, suggest that the introduction of standards equivalent in stringency to U.S. Tier 3 in China can significantly reduce evaporative emissions relative to China 6. [ABSTRACT FROM AUTHOR]

This paper evaluates the potential of using biodiesel from Dunaliella tertiolecta in the internal combustion engine to reduce emissions and fuel consumption and increase power output. The high cost of microalgae biomass production, the low efficiency of converting biomass into biodiesel and the increase in NOx production and fuel consumption with the combination of biodiesel in high percentages are the problems of this issue. In this article, by using the new solar still desalination/parabolic trough collector/geothermal hybrid system to supply the required water and heat and to investigate the effect of the influencing factors, the efficiency of microalgae production and transesterification process's conversion efficiency were obtained as 1.04 g/L and 80.22%, respectively. The addition of biodiesel from 0% to 20% in the fuel decreased CO, SOx and HC emissions, but CO 2 and NOx emissions increased. Also, fuel consumption increased and engine output power decreased. The optimum point was found in order to emit the least emissions and reduce fuel consumption and increase the output power for the composition percentage of 11.5% biodiesel in the fuel. [Display omitted] [ABSTRACT FROM AUTHOR]

The need for reducing fossil fuel consumption and greenhouse gas (GHG) emissions in internal combustion engines has raised the opportunity for the use of renewable energy sources. For the progressive replacement of fossil fuels like diesel, those derived from the sustainable management of forest resources may be a good option. In Portugal, pine trees (pinus pinaster) are among the most widely cultivated tree species. Turpentine can be extracted from their sap without harming the tree. Turpentine is known to be a good fuel with a lower viscosity than regular diesel but with a comparable caloric value, boiling point and ignition characteristics, although it is not widely used as a compression ignition fuel. Moreover, recent research has highlighted the possibility of substantially increasing the turpentine yield through biotechnology, bringing it closer to economic viability. The present study investigates the performance, pollutant emissions and fuel consumption of a 1.6 L four-cylinder direct-injection diesel engine operating with several blends of commercial diesel fuel and turpentine obtained from pine trees. The aim of this study was to assess whether it would be possible to maintain or even improve the performance, fuel consumption and GHG and pollutant emissions (HC, NOx, CO and PM) of the engine with the partial incorporation of this biofuel. Turpentine blends of up to 30% in substitution of regular diesel fuel were tested. The main novelties of the present work are related to (i) the careful testing of a still-insufficiently studied fuel that could gain economical attractiveness with the recent developments in yield improvement through biotechnology and (ii) the tests conducted under fixed engine load positions typical of road and highway conditions. The addition of this biofuel only slightly impacted the engine performance parameters. However, a slightly positive effect was observed in terms of torque, with an increase of up to 7.9% at low load for the 15T85D mixture and 6.8% at high load being observed. Power registered an increase of 9% for the 15T85D mixture at low speed and an increase of 5% for the 30T70D mixture at high speed when compared to the reference fuel (commercial diesel fuel). While the efficiency and fossil GHG emissions were improved with the incorporation of turpentine, it had a mixed effect on polluting emissions such as unburned hydrocarbons (HC) and smoke (PM) and a negative effect on nitrogen oxides (NOx). NOx emissions increased by 30% for high loads and 20% for low loads, mainly as an indirect effect of the improvement in the engine performance and not so much as a consequence of the marginally higher oxygen content of turpentine relative to commercial diesel fuel. [ABSTRACT FROM AUTHOR]

The waste thermal energy of exhaust gases in internal combustion engines has a high energy potential that is usually untapped. Using technologies such as thermoelectric generators is one of the most promising strategies for recovering this waste heat. In the current research, an analysis of the electrical characteristics of a thermoelectric generator connected to the exhaust system of an internal combustion engine was carried out. The study was focused on the influence of operational conditions (external resistance, number of modules, mass flow, and exhaust gas temperature) on the electrical parameters. The results show that the increase in mass flow and exhaust gas temperature increases 97.44% and 104.95% in recovered power. Additionally, the increase in these operating parameters leads to a 14.04% and 19.05% increase in energy conversion efficiency. The increase in the number of thermoelectric modules allows for increasing the recovered power. However, it is necessary to properly evaluate the arrangement of the TEMs on the surface to avoid reductions in the TEG conversion efficiency. Overall, the thermoelectric generator allowed maximum output power of 56.62 W, equivalent to 2% of the engine output shaft power. This implies a reduction in the fuel injected into the engine. [ABSTRACT FROM AUTHOR]

The most effective way to reduce internal combustion engine emissions is to use a sustainable alternative fuel that contains oxygen molecules. Alternative fuels may be used to address a future global energy crisis. Different oxygenated alternative fuels have been investigated in internal combustion engines. Polyoxymethylene di-methylene ether (PODE), which contains 3–5 CH2O groups, is currently superior in the field of oxygenated fuels due to its physical and chemical properties. Furthermore, using PODE as a fuel does not necessitate any significant engine modifications. When compared to standard diesel fuel, the use of PODE results in near stoichiometric combustion with less hazardous exhaust gas. It also significantly reduces NOx emissions due to the lack of C-to-C bonds. Several articles in the literature were found on the manufacturing and application processes for the production of PODE. However, the current review focuses primarily on simplifying the various production technologies, the physical and chemical properties of PODEn and its advantages and disadvantages in ICEs, PODEn application in internal combustion engines and its characteristics, PODE spray analysis, and measurements of the fuel's physical and chemical characteristics. This review emphasizes the fact that PODE can be used as a sole fuel or in conjunction with fossil fuels and advanced combustion technologies. Because C-C bonds and higher oxygen molecules are not available, the trade-off relationship between nitrogen oxides and soot production is avoided when PODEn is used as a fuel, and combustion efficiency is significantly improved. [ABSTRACT FROM AUTHOR]

Harvesting residual thermal energy from exhaust gases with thermoelectric generators is one of the paths that are currently being explored to achieve more sustainable and environmentally friendly means of transport. In some cases, thermoelectric generators are installed in a by-pass configuration to regulate the mass flow entering the thermoelectric generator. Some manufacturers are using throttle valves with electromechanical actuators and electronic control in the exhaust pipe to improve techniques for active control of pollutant emissions in reciprocating internal combustion engines, such as the exhaust gas recirculation. The above-mentioned circumstances have motivated the approach of this work: computational fluid dynamics (CFD) modelling of the operation of a throttle valve used for establishing adequate exhaust backpressure conditions to achieve the low pressure exhaust gas recirculation in Euro 6 engines. The aim of this model is to understand the flow control process with these types of valves in order to incorporate them in an exhaust system that will include two thermoelectric generators used to convert residual thermal energy into electrical energy. This work presents a computational model of the flow through the throttle valve under different temperatures and mass flow rates of the exhaust gas with different closing positions. For all cases, the values of the pressure drop were obtained. In all cases studied, the level of agreement between the modelled and experimental results exceeds 90%. The developed model has helped to propose a correlation to estimate the mass flow rate of exhaust gas from easily measurable quantities. [ABSTRACT FROM AUTHOR]

Future options for addressing the depletion of fossil fuels and reducing pollution from internal combustion engines may include biofuel as an alternative fuel. This study aims to experimentally and statistically assess the effect of using diesel-biofuel blends on the emissions of a single-cylinder direct-injection engine. Using recycled olive oil, a chemical Tran’s esterification process was used to create biofuel. The experimental results were contrasted with those of a one-dimensional engine model for exhaust emissions and torque, which showed high agreement between test and numerical data. In order to comprehend the factors that affect the engine’s reaction to variations in fuel composition, the thermodynamic characteristics of the engine for various blends were also supplied. According to the investigation, a mixture with 20% of the volume fraction of oleic acid methyl ester olive-based biofuel and 80% of the volume fraction of pure diesel can be an effective fuel alternative for cleaner exhaust emissions while offering almost the same performance. [ABSTRACT FROM AUTHOR]

This paper investigates the design of a thermoelectric generator for exhaust gases from internal combustion engines. Experimentally validated CFD methodology was employed. Different issues are studied, such as the influence of the replacement of the exhaust pipe for the TEG, the recirculation produced, and the influence of fins. The results show that an enlarged inlet cone reduces the recirculation and the pressure drop of the TEG, but more heat is lost across the cone walls, reducing the heat available for the thermoelectric modules. Internal straight fins aligned with the flow achieved a 3% increase in heat transfer, did not significantly increase the pressure drop in this type of device, and reduced the effects on pressure of the recirculation, lowering the overall pressure drop by 10%. An energy production of 175.9 W with 16.2 W of pressure drop power losses resulted in a net energy production of 160.7 W. A comparison with a flat-type thermoelectric generator under the same hot source conditions is also provided. [ABSTRACT FROM AUTHOR]

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Carbon-based nanomaterials have excellent properties and can be used in fuels to reduce emissions and improve engine performance and fuel economy. Due to their unique thermal conductivity properties, nanoparticles are widely used in various ways. The current article analyzes research results on the influence of carbon nanoparticles on the working characteristics and emissions of internal combustion engines powered by diesel and biodiesel. Fuels were mixed with the nanomaterial CPL at different concentrations (50, 100, and 150 ppm). This article analyzes the influence of nanomaterial (carbon wafers) in diesel engines using diesel and biodiesel to reduce emissions and fuel consumption, evaluates the volume of nanomaterials as a fuel additive needed to improve emission performance, and investigates the problem of the practical application of nano-fuel (i.e., regarding dosage and stability). [ABSTRACT FROM AUTHOR]