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Biogas is produced from organic materials, typically containing methane (CH 4) with content varying between 50% and 70%, and carbon dioxide (CO 2) ranging from 30% to 50%. It may also include hydrogen (H 2) with appropriate source material. Biogas is commonly utilized for power or heat generation in combined heat and power systems. The Homogeneous Charge Compression Ignition (HCCI) engine is well-suited for this purpose due to its efficient and rapid combustion process, with a lean air-fuel mixture. However, to limit the high pressure rise rate resulting from simultaneous premixed combustion in the engine cylinder, the combustion process must be controlled. The dilution inherent to this combustion mode helps in limiting the maximum cylinder temperature, and so the nitrogen oxides emissions. Moreover, particulate emissions can be lower than with diesel engine due to the homogeneous charge. Nonetheless, hydrocarbon (HC) and carbon monoxide (CO) levels are greater than those observed with spark ignition (SI) combustion. Additionally, high intake temperatures are needed to operate HCCI engines, depending on compression ratio, intake pressure, fuel type, and equivalence ratio. This paper focuses on an experimental study involving a modified diesel engine initially built for passenger vehicles, adapted to run in HCCI mode. Different fuel mixtures containing methane, hydrogen, and carbon dioxide with a fixed equivalence ratio of 0.4 were tested to reproduce an innovative biogas composition naturally containing hydrogen. The intake temperature and pressure were set according to the fuel mixtures to properly phase the combustion onset. A combustion analysis has been conducted to determine the effect of fuel composition on the combustion process. For each fuel type, the optimal intake pressure and temperature for achieving best combustion timing were identified, resulting in a peak indicated efficiency of 40% and specific NOx emissions as low as 0.1 g/kWh. Results show the effect of both CH 4 /H 2 ratios and CO 2 content as well as intake conditions on the load (IMEP), efficiencies, engine stress (i.e. pressure gradient) and emissions. [Display omitted] • Hydrogen reduces intake temperature and pressure requirements for HCCI combustion. • Maximum in-cylinder pressure is highly sensitive to intake temperature and pressure. • Findings indicated excellent combustion stability and Indicated efficiency of 40%. • Fuels containing CO 2 showed very low NOx emissions. [ABSTRACT FROM AUTHOR]

The article analyzes the environmental costs of Diesel Multiple Unit and Diesel Railcars operated in Poland. It consisted in determining the annual cost of gases and particulate matter emitted into the ambient air by the analyzed rolling stock. For this purpose, tests were carried out on the emission of harmful exhaust gases from a railbus equipped with the most commonly used drive system. The vehicle had two identical compression ignition engines meeting the Stage IIIB standard with a displacement of 12.8 dm3. Maximum power of the engine was 390 kW at a rotational speed of 1800 rpm and a maximum torque of 2200 Nm at 1300 rpm. In order to measure harmful exhaust compounds, tests were carried out in real operating conditions using Portable Emission Measurement System (PEMS) equipment. The tests carried out in track conditions showed that the rail vehicle did not meet the approval limits for nitrogen oxides (real value -- 2.43 g/kWh, emission standard -- 2.0 g/kWh). However, it should be remembered that the limit values are established in stationary tests and not in actual operating conditions. In the next stage, the annual emissions of rail buses operating in Poland were estimated. For this purpose, data from the Office of Rail Transport on the number of vehicles registered in the country and the average distance traveled by the vehicles were used. The data obtained indicate that the vast majority (over 98%) of environmental costs are costs related to carbon dioxide emitted into the atmosphere. [ABSTRACT FROM AUTHOR]

This study examined the impact of varying concentrations of ammonia-borane (AB) in gasoline on engine performance and emissions across different load conditions. Four fuel formulations were tested: pure gasoline (G100) and gasoline blends containing 10%, 15%, and 20% AB (AB10, AB15, AB20). Increased AB concentration resulted in higher brake-specific fuel consumption (BSFC). While exhaust gas temperatures were highest with G100 (730.9 °C at full load), the AB blends, particularly AB20, exhibited lower temperatures, with a maximum reduction of 13.8%. The AB20 blend demonstrated elevated BSFC and increased oxygen (O₂) emissions but significantly reduced carbon monoxide (CO) emissions, with up to an 88.2% decrease at full load. Nitrogen oxide (NO x) emissions were generally lower for all AB blends. The highest NO x value was measured with G100 fuel at full load, while the lowest NO x value was measured with AB10 fuel. Under these conditions, a 23% decrease in NO x value was observed with AB10 fuel compared to G100. The engine's thermal efficiency decreased with AB blends at all load levels compared to pure gasoline. Thermal efficiency decrease of 13.76%, 22.32%, and 30.88% occurred for AB10, AB15 and AB20, respectively compared to G100.Overall, incorporating AB in gasoline reduced thermal efficiency and led to a notable decrease in NO x , hydrocarbons (HC), and CO emissions. [Display omitted] • Alcohol-gasoline blend fuels AB10, AB15 and AB20 were created. • All blended fuels were tested in a single cylinder gasoline engine. • AB blends show higher brake specific fuel consumption (BSFC) values compared to pure gasoline. • AB10, AB15 and AB20 showed lower thermal efficiency compared to G100 at all engine loads. • AB blends reduced harmful emissions such as CO, HC and NOx. [ABSTRACT FROM AUTHOR]

Liquid e-fuels such as methanol represent a possible solution to emission-neutral drivetrains. Reduced emissions from the combustion process increase the influence of cylinder wall interaction of the fuel spray and the influence of the fuel ingress into the lubricating oil. Combining emission analysis methods and optical measurements allows a deeper understanding of the processes around the piston assembly group and cylinder wall. This paper aims to increase the understanding of the processes resulting from fuel spray and cylinder wall interaction. Emission measurements from a single-cylinder SI research engine were gathered across multiple operating parameters. Optical measurements were taken at similar operating points using an optically accessible engine. A laser-induced fluorescence (LIF) setup with dyed fuel was used for the optical measurements. This paper focuses on thermodynamic steady state measurements at 2000 rpm, varying loads between 3 and 11 bar IMEP, and corresponding optical measurements at 11 bar IMEP. The measurements of both engines were correlated, and a more profound understanding of the processes involved and their influence on emission behavior was derived. Measurements showed a lower particle emission behavior with a tendency of a higher PN10 to PN23 ratio and higher formic acid emissions using methanol fuel compared to gasoline. A higher wall film interaction with methanol could be visualized, and possible effects were correlated to the exhaust emission measurements. Tests with two start of injection timings (SOI) of 430° crank angle (CA) after fired top dead center, as used for gasoline operation, and 550°CA as an optimized SOI for methanol operation were compared. A correlation between the results from the thermodynamic engine and the optically accessible engine was demonstrated. The optical measurements showed lower penetration depths for the optimized SOI and lower fuel spray-to-piston interaction. The thermodynamic measurements have shown higher efficiencies and fewer emissions for the optimized SOI. [ABSTRACT FROM AUTHOR]

The study delves into how vehicle engine characteristics impact the release of air pollutants from various vehicle fleets in Lagos, Nigeria. It involved the direct measurement of emissions from the exhaust pipes of 88 vehicles using gas analyzers. The vehicle fleets encompassed motorcycles, tricycles, private cars, minibuses, large buses, and trucks. A statistical analysis was conducted on carbon monoxide (CO) and nitrogen oxide (NOx) emissions to develop a model equation based on vehicle type, engine type, vehicle age, and purchase status. Results indicate that personal cars and minibuses predominantly emit CO from gasoline engines, whereas large buses and trucks significantly contribute to NOx emissions from diesel engines. Further scrutiny revealed that 66% of the vehicles examined were over 10 years old, resulting in a 65% increase in emission levels. Approximately 60% of gasoline and 75% of diesel vehicles exceeded the permissible emission limits, leading to air quality deterioration and heightened health risks. The study underscores the risks associated with ageing vehicles and different engine types, emphasizing the imperative for a gradual transition to low-carbon or electric vehicles in developing African cities to combat air pollution and mitigate health hazards. [ABSTRACT FROM AUTHOR]

In modern society where fossil fuel prices are increasing and environmental issues are becoming more severe, biodiesel, as a new type of clean fuel, is receiving increasing attention. Biodiesel has the advantages of renewability, environmental friendliness, and good fuel properties, demonstrating broad application prospects. However, the use of biodiesel also faces some challenges, such as higher density and kinematic viscosity, lower calorific value, etc. The application of nanoparticles in biodiesel engines helps to achieve the goal of clean fuel. In terms of fuel characteristics, nanoparticles increase the calorific value, cetane value, and flash point of the fuel, improving combustion efficiency and safety, but increasing density may affect combustion. The use of nanoparticles can promote micro explosions and secondary atomization of fuel, improve combustion characteristics, and increase cylinder pressure, heat release rate, and brake thermal efficiency while reducing fuel consumption. Nanoparticles reduce HC and CO emissions, improve combustion through higher oxygen and reaction area, and reduce incomplete combustion products. On the contrary, nanoparticles also increase CO2 emissions because better combustion conditions promote oxidation reactions. For NOX emissions, some nanoparticles lower the combustion temperature to reduce emissions, while others increase emissions. Comparison shows that all nanoparticles offer varying degrees of improvement in engine performance and emissions, but the improvement provided by TiO2 nanoparticles is significantly better than that of other nanoparticles. In the future, the synergistic effect of multiple nanoparticles should be explored to further improve performance and reduce emissions, achieving effects that cannot be achieved by a single nanoparticle. [ABSTRACT FROM AUTHOR]

The hydrogen-diesel dual-fuel mode is an efficient way of lowering exhaust emissions from compression-ignition engines. Along with exhaust emissions, mechanical vibration and noise emissions are also problems for these engines. In dual fuel mode, it is possible to reduce all emissions by using the appropriate injection strategy. In this study, different injection strategies were used in an engine with an ECU-controlled liquid and gas fuel system. In experiments, constant load (5 Nm), constant speed (1850 rpm), constant hydrogen energy ratio (12%), 4 different hydrogen injection pressures (1, 1.5, 2.0, and 2.5 Bar), and 5 different hydrogen injection starts (25, 35, 45, 55, and 65 °CA aTDC) were performed. In the study, exhaust, mechanical vibration, and noise emissions were recorded and analysed. When a few of the study's data were looked at, it was determined that CO 2 emissions decreased by 33.4% and PM emissions by 40.7% at 25 °CA aTDC injection start and 2.5 bar injection pressure. Under the same experimental conditions, NO emissions increased by 8.7%, mechanical vibration emissions increased by 19.9%, and noise emissions increased by 2 dBA. [Display omitted] • H 2 -diesel dual fuel use is effective in reducing CO, CO 2 and soot emissions. • In dual fuel mode, H 2 increased NO, mechanical vibration, and noise emissions. • Increasing the injection timing in dual fuel mode reduces emissions. • H 2 injection being lower than 25 °CA aTDC risks combustion safety. [ABSTRACT FROM AUTHOR]

The environmental and air pollution brought about by the increasing energy consumption has increased the interest in the use of renewable energy sources in the transportation sector, where internal combustion engines are used, which is responsible for a large part of the exhaust emissions. Alcohol fuels have been evaluated as renewable energy sources for utilising in internal combustion engines and they are reported to have lowering exhaust emissions and costs. This study analyses four monohydric aliphatic alcohol fuels (methanol, ethanol, propanol and butanol) by reviewing the available literature to represent their applicability as an alternative fuel in internal combustion engines. In the study, researches on the directly use of acetone–butanol–ethanol and isopropanol–butanol–ethanol as alcohol fuel were also examined because the production of butanol by acetone–butanol–ethanol and isopropanol–butanol–ethanol distillation is costly, and isopropanol–butanol–ethanol is more preferred due to the corrosive feature of acetone. The higher fuel consumption of alcohol fuels than fossil fuels was the most common result, with reductions in NOx and smoke emissions except for isopropanol–butanol–ethanol, which had higher NOx emissions. It has been reported that less carbon and high oxygen content, low cetane number and high latent heat of alcohol fuels are responsible for the above results. The increase in thermal efficiency with the use of acetone–butanol–ethanol and isopropanol–butanol–ethanol in contrast to other alcohol fuels was a notable result. A comparison among the alcohol fuels showed that methanol was more effective than ethanol in reducing CO, unburned HC and smoke emissions while isopropanol–butanol–ethanol demonstrated high NOx emissions. A simultaneous reduction of NOx and Smoke emissions, which was commonly reported for most of alcohol fuels, makes a significant contribution to the development of internal combustion engines. This study gains importance in terms of comparing the individual effects of the use of alcohol fuels on exhaust emissions and better understanding the current status of these fuels. [ABSTRACT FROM AUTHOR]

The transportation sector is responsible for about 16% of worldwide greenhouse gas emissions. Despite efforts for a sensible reduction by means of new technologies' development, the average age of a vehicle fleet is 12.3 years in the European Union. In light of this, actions aiming at improving the efficiency of circulating vehicles can prove effective in the short to mid-term. Introducing performance packages in standard fuels could allow a reduction in the CO2 emissions of whole vehicle fleets without any modification to powertrain. Such a kind of additive is generally used in premium fuels; deposit control additives can reduce or control the deposits at intake valves and at nozzle holes with benefits for the fuel efficiency and exhaust emissions. Further improvements in combustion phasing can be achieved with cetane/octane improver. This paper aims to assess the influence of two performance packages on the exhaust emissions and fuel consumption of five vehicles set to be as representative as possible of circulating Italian passenger cars and light commercial fleet vehicles (LCVs). Based on the literature datasets, three Euro 4 vehicles were selected with a mileage representative of each single vehicle class: two passenger cars (one spark ignition and one diesel) and an LCV. Further, two diesel Euro 6 vehicles, a passenger car and an LCV, were tested to investigate the effect of fuel additives on the combustion of vehicles compliant with current homologation regulation. Exhaust emissions and fuel consumption were experimentally estimated on a chassis dynamometer over a worldwide harmonized light vehicles test cycle (WLTC) in a climate-controlled laboratory. Each vehicle was preliminarily tested when running with base fuel, then a 3000 km clean-up stage was performed using the additive package. Finally, WLTC tests were repeated. Results demonstrated the efficiency of the performance packages with a reduction between 1.2% (diesel Euro 6 passenger car) and 8.1% (diesel Euro 4 passenger car) in fuel consumption. Similar trends were found for CO2 emissions. Further, a sensible reduction in THCs, CO and PM was found for each vehicle class. [ABSTRACT FROM AUTHOR]

The development of compression ignition combustion engines is focused on meeting many challenges, mainly related to growing ecological requirements. Currently, however, due to technological barriers, meeting them is very difficult and requires the use of additional exhaust gas treatment systems. The use of injection of a diesel and gas solution seems to be very promising. The article presents the results of engine tests involving the use of a solution of diesel fuel and dimethyl ether. The tests were performed on a single-cylinder research engine equipped with a common rail fuel system. The obtained results suggest that the use of the solution has a positive effect on the process of creating the fuel-air mixture, resulting in a reduction in the concentration of HC and CO while increasing the share of NOx, suggesting an improvement in the combustion process, as evidenced by the limiting injection dose. [ABSTRACT FROM AUTHOR]

This study focuses on investigating the significant impacts of speed breakers on various parameters, including travel time delays, vehicle speeds, fuel consumption, pavement maintenance costs, and vehicular exhaust emissions. Field data was collected and analyzed to assess the effects of different types of traffic calming measures on these parameters. The findings provide valuable insights into the implications of speed breakers on road safety, environmental pollution, and overall road infrastructure management. The results reveal that the implementation of speed humps, speed bumps, and triple bumps effectively slows down vehicles, as evidenced by considerable reductions in the 85th percentile speeds. The reduction percentages were 41.65% for speed humps, 73.52% for speed bumps, and 86.27% for triple bumps. This indicates the effectiveness of these traffic calming measures in improving road safety by reducing vehicle speeds. However, the presence of speed breakers also leads to increased travel time delays. On average, traversing stretches with speed humps, speed bumps, and triple bumps resulted in delays of 9.31, 16.42, and 29.51 seconds, respectively. While the individual delay times may appear relatively short, the cumulative effect of multiple speed obstacles along a road needs to be considered. Another significant impact observed is the increased fuel consumption associated with speed breakers. The study found that for every 100 km of travel, motorcycles and passenger cars consumed approximately 12.07 km and 27.37 km of additional fuel, respectively, when the density of speed breakers was 1.33/km. This translates to a fuel consumption increase of 13.73% for motorcycles and 37.74% for passenger cars. Furthermore, the presence of speed humps was found to contribute to pavement deterioration, as indicated by decreased Pavement Condition Index (PCI) values. The study also revealed that sections with speed humps incurred significantly higher maintenance costs compared to sections without speed humps. The increase in maintenance cost ranged from 100 to 264% across different road sections, with higher traffic volumes leading to greater cost escalation. Additionally, the study confirms that lower vehicle speeds, particularly between 0-15 km/hr, are associated with higher emissions of pollutants, including carbon monoxide (CO) and other pollutants. This highlights the environmental implications of speed breakers and their contribution to urban air pollution. [ABSTRACT FROM AUTHOR]

Particle emissions from marine activities next to gaseous emissions have attracted increasing attention in recent years, whether in the form of black carbon for its contribution to global warming or as fine particulate matter posing a threat to human health. Coastal areas are particularly affected by this. Hence, there is a great need for shipping to explore alternative fuels that both reduce greenhouse gas emissions, as anticipated through IMO, and also have the potential to reduce particle emissions significantly. This paper presents a comparative study of the particulate emissions of two novel synthetic/biofuels (GTL and HVO), which might, in part, substitute traditionally used distillate liquid fuels (e.g., MDO). HFO particulate emissions, in combination with an EGCS, formed the baseline. The main emphasis was laid on particle concentration (PN) and particulate matter (PM) emissions, combining gravimetric and particle number measurements. Measurements were conducted on a 0.72 MW research engine at different loads (25%, 50%, and 75%). The results show that novel fuels produce slightly fewer emissions than diesel fuel. Results also exhibit a clear trend that particle formation decreases as engine load increases. The EGCS only moderately reduces particle emissions for all complaint fuels, which is related to the formation of very fine particles, especially at high engine loads. [ABSTRACT FROM AUTHOR]

This article examines the impact of on-road vehicle emissions on mortality rates in Perth, Australia. Using a particle modeling framework, the study found that long-term exposure to vehicle pollution is responsible for 66 premature deaths annually in Perth, costing an estimated AUD 150 million each year. The study emphasizes the need for reducing air pollution from traffic to improve public health, but acknowledges the limitations of current emissions inventories and calls for further research to accurately assess emissions factors in an Australian context. The article also discusses the importance of public health policies promoting lower emission vehicles and the potential health benefits for Australian city dwellers. It references other studies on the mortality burden of vehicle emissions and the effects of wood heater pollution. Overall, the article provides valuable information on the current state of vehicle emissions and their implications for public health. [Extracted from the article]

Biodiesel has emerged as a compelling substitute for conventional diesel fuel, providing a sustainable and eco-friendly choice for fueling compression ignition engines. This comprehensive study investigates the influence of biodiesel, specifically derived from sunflower oil, through the esterification method, on crucial engine performance parameters and environmental effects. The study examines the impact of varying engine torque on the performance of a single-cylinder, four-stroke compression ignition engine, encompassing parameters such as brake thermal efficiency (BTE) and brake specific fuel consumption (BSFC), as well as exhaust emissions, including unburned hydrocarbons (HC), carbon monoxide (CO), and nitrogen oxides (NOx). Four distinct biodiesel blends (B10, B20, B30, B40) with varying sunflower oil content are systematically compared to pure diesel (B0). The engine operates at a consistent speed of 1700 rpm, while the torque undergoes controlled adjustments from 0 to 10 Nm. Subsequently, this study explores the application of an alternating model tree (AMT) machine learning algorithm to establish relationships between independent factors, specifically torque and biodiesel volume (%vol), and dependent variables, including BTE, BSFC, CO, and NOx in a combustion engine. Additionally, the study employs a multi-objective ameliorative whale optimization algorithm (AWOA) to optimize the model's output. The objective is to identify optimal values for torque and%vol that maximize engine performance (BTE) while minimizing engine emissions (CO and NOx) and reducing fuel consumption (BSFC). The optimization process yields noteworthy results, with AWOA achieving peak BTE at 29.714 %, BSFC at 0.262 kg.kWh-1, and NOx emissions at 992 ppm at torque 7.3 N.m and 13% vol. In contrast, particle swarm optimization (PSO) secured the minimum CO level at 0.123 %, with torque set at 7.6 N.m and 26% vol. The AMT models demonstrate high prediction accuracy, with coefficient of determination (R2) values exceeding 0.98.

The purpose of this study is to investigate the performance, in-cylinder combustion, and emissions of the MTE660E heavy-duty diesel engine using 3D CFD simulation. The CFD simulation model based on AVL FIRE software was developed to numerically investigate the performance, in-cylinder combustion, and emissions of the MTE660E engine. The AVL model was validated against empirical data. The 6-cylinder MTE660E engine was operated under a constant excess air ratio of 1.75 and at 1600 rpm engine speed. The geometry and lattice design of the MTE660E engine were simulated to provide a computationally efficient approach. The AVL model was validated against experimental data and the error between the measured and calculated value of combustion characteristics and emissions was acceptable (R2> 90 %), error

The gathering effect of trucks at freight terminals and the high emission characteristics of trucks themselves lead to long-term truck queues and serious environmental pollution problems at freight terminals. Repeated stopping and following trucks aggravate the environmental pollution in the terminal. This paper proposes a scheme to plan truck parking spaces during waiting for trucks to enter the freight terminal in order to reduce the repeated stopping of trucks and to quantify the environmental benefits of truck parking spaces in the process. The truck admission process was simulated using the Visual Simulator (VISSIM). The simulation output provided vehicle operating data that was converted into operating mode distribution data using the Python calculation module. Then, the model parameters, including the operating mode distribution, were entered into the Motor Vehicle Emission Simulator (MOVES) to calculate the simulation scenario. Gangchen Logistics Park, for example, statistics of the park's 10 months of freight data, the design of freight volume gradually increased by 11 groups of admission simulation experiments, the simulation learned that the park queuing significant, more than 90% probability of queuing, queuing up to a maximum of 203 vehicles, the average queue of 61 vehicles. Then according to the actual road conditions in the park, add a parking lot in the VISSIM simulation. Signal sensing is realized by calling the COM interface of VISSIM through Python to guide the vehicles to park in order and enter the park. Eleven sets of simulation control experiments after designing and planning parking spaces are designed to calculate the pollutant emissions for each simulation scenario separately. The analysis of the emission measurement results shows that the emissions of CO, HC, NOX, and PM10 can be reduced by 1.90%, 7.90%, 9.42%, and 10.55% at the average level of the park's cargo volume. At the park's maximum cargo volume, it is possible to reduce HC, NOX, and PM10 emissions by about one-third. Truck parking space in the truck waiting to drive into the freight terminal process has obvious environmental benefits, queuing significant freight terminals should be reasonably planned truck parking spaces to reduce the freight terminal exhaust emissions pollution.

In this study, waste biomass-derived biogas was employed as the main fuel while the biodiesel-diesel blend was used as pilot fuel. This paper describes the development of a Decision Tree and Response Surface methodology-based statistical framework for prediction modeling and optimization. The compression ratio, fuel injection time, fuel injection pressure, and biogas flow rate were employed as controllable inputs, and brake thermal efficiency, peak combustion pressure, and exhaust emission were selected as responses. The experimental data for model development was gathered for the development of prediction models and optimization. The decision tree-based models were robust with almost negligible mean squared errors and R2 values of more than 0.9487 for all models. Response surface methodology-based optimized engine parameters were validated with the following results compression ratio was 17.9, fuel injection pressure was 225 bar, fuel injection timing was 26.3-degree crank angle after top dead center, and the biogas flow rate was 0.85 kg/h. Validation results were within 5 % of the model-optimized results. The prognostic models for all control factors were developed with decision tree-based machine learning with high predictive efficiency and low errors.

The rapid increase in the number of motorized vehicles has resulted in the depletion of the availability of fossil-based fuel oil. Bioethanol from sugarcane molasses waste is an alternative that can be applied to vehicles with the condition that it has 99.95% ethanol fuel grade. The study used a bioethanol sample fuel blend BE10 (Bioethanol 10%+90% Pertalite), and then conducted property testing and Gas Chromatography Mass Spectrometry (GCMS) to observe the compound structure of the fuel. Modification of the ignition timing forward 2o (+2) was done by reprogramming the Engine Control Module (ECM). The addition of up to 20% bioethanol to pertalite increased the octane number from 90 to 93.1. However, the heating value decreased from 42.5 to 39.18 MJ/kg. In the GC-MS test, the number of compounds in the fuel increased to 52 and 51 compounds, respectively. The highest improvement in engine performance of all parameters using bioethanol and advance ignition was sample (BE10+2). The thermal efficiency was 6.16%. Thus, the use of bioethanol fuel blends and ignition timing modifications can be applied to vehicles to get good performance and be more environmentally friendly.

Abstract Positive pressure ventilators (PPV) used by 97.7% of officers of the National Fire Service in Poland, are characterized by work that is not in line with the expectations of the firefighters. In order to improve the technical and operational features of these devices, a survey was conducted among 25,000 eligible firefighters, identifying the application of these devices, problems in use and expected development directions. A total of 682 officers voluntarily completed the survey. Based on their findings, it was determined that ventilators are most often used to smoke out buildings after or during a fire. Mentioned problems when using these devices were mainly noise (78.2%), exhaust emissions (68.5%), and impediments to mobility through the device’s relatively heavy weight (40.2%). Other inconveniences were mentioned by less than 20% of firefighters. Polish firefighters expect the development of these devices mainly in terms of the above-mentioned features (noise reduction (81.7%) and reduction of the weight and size of the ventilators (about 50%)). Other expectations relate to the improvement of smoke removal in buildings: increasing the efficiency of smoke removal (46.4%) and efficiency regarding the rate of smoke removal in a building by increasing the size of the incoming airflow from the building’s surroundings (33.2%). About 15% of firefighters expect changes in the operation of the ventilator itself, that is, an increase in the effective operating time (electric ventilators) and an increase in the device’s uptime. The aim of the article is to identify the issues encountered during the operation and to indicate the expected direction of development for PPV by users. This information can be used by engineers to initiate new development work on these devices.

The study delves into how vehicle engine characteristics impact the release of air pollutants from various vehicle fleets in Lagos, Nigeria. It involved the direct measurement of emissions from the exhaust pipes of 88 vehicles using gas analyzers. The vehicle fleets encompassed motorcycles, tricycles, private cars, minibuses, large buses, and trucks. A statistical analysis was conducted on carbon monoxide (CO) and nitrogen oxide (NOx) emissions to develop a model equation based on vehicle type, engine type, vehicle age, and purchase status. Results indicate that personal cars and minibuses predominantly emit CO from gasoline engines, whereas large buses and trucks significantly contribute to NOx emissions from diesel engines. Further scrutiny revealed that 66% of the vehicles examined were over 10 years old, resulting in a 65% increase in emission levels. Approximately 60% of gasoline and 75% of diesel vehicles exceeded the permissible emission limits, leading to air quality deterioration and heightened health risks. The study underscores the risks associated with ageing vehicles and different engine types, emphasizing the imperative for a gradual transition to low-carbon or electric vehicles in developing African cities to combat air pollution and mitigate health hazards.

Positive pressure ventilators (PPV) used by 97.7% of officers of the National Fire Service in Poland, are characterized by work that is not in line with the expectations of the firefighters. In order to improve the technical and operational features of these devices, a survey was conducted among 25,000 eligible firefighters, identifying the application of these devices, problems in use and expected development directions. A total of 682 officers voluntarily completed the survey. Based on their findings, it was determined that ventilators are most often used to smoke out buildings after or during a fire. Mentioned problems when using these devices were mainly noise (78.2%), exhaust emissions (68.5%), and impediments to mobility through the device's relatively heavy weight (40.2%). Other inconveniences were mentioned by less than 20% of firefighters. Polish firefighters expect the development of these devices mainly in terms of the above-mentioned features (noise reduction (81.7%) and reduction of the weight and size of the ventilators (about 50%)). Other expectations relate to the improvement of smoke removal in buildings: increasing the efficiency of smoke removal (46.4%) and efficiency regarding the rate of smoke removal in a building by increasing the size of the incoming airflow from the building's surroundings (33.2%). About 15% of firefighters expect changes in the operation of the ventilator itself, that is, an increase in the effective operating time (electric ventilators) and an increase in the device's uptime. The aim of the article is to identify the issues encountered during the operation and to indicate the expected direction of development for PPV by users. This information can be used by engineers to initiate new development work on these devices. [ABSTRACT FROM AUTHOR]

Biodiesel is a promising alternative fuel, but it has drawbacks. This research aims to diminish the NOx dilemma for diesel and biodiesel by utilizing straight-run naphtha as an additive. It has a low carbon footprint of production from light distilled crude oil without any requirement for the thermal cracking process. The diesel was blended with naphtha at percentages of 5%, 10%, and 15% that abbreviated by N5, N10, and N15, respectively. The biodiesel/diesel blend was mixed with the same naphtha concentrations forming the blends B30N5, B30N10, and B30N15, respectively. Experiments were applied on a single-cylinder engine at 2,000 rpm and different loads. The findings revealed that N15 declined the brake specific fuel consumption (bsfc) at most loads relative to neat diesel. Contrarily, biodiesel blends reflected a spiking trend of bsfc at tested loads. Notably, the NOx emissions declined with N15 blend at high loads relative to neat diesel. The blends B30N15 and B30N10 reduced NOx at high loads compared to the diesel/biodiesel blend. The straight-run naphtha was found to be a promising additive because the balanced composition of the iso-paraffins and n-paraffins. Hence, it dominated the ignition tendency and reduced NOx emissions due to its cooling effect. [ABSTRACT FROM AUTHOR]

This article presents the impact of vehicle traffic intensity and the closure of access roads for wheeled vehicles to selected schools in Warsaw at selected hours of the day on changes in air quality. This study focused primarily on analyses related to the pollutant typical of road traffic, i.e., nitrogen dioxide, but also took into account PM10 and PM2.5 concentrations, which are some of the key factors determining the quality of atmospheric air, the sustainability of human beings, and sustainable development. Some kinds of relationships were found between vehicle traffic intensity and air pollutant concentrations, in particular—nitrogen dioxide. Analyses of the pollutant concentrations in the periods before and after the introduction of restrictions on vehicle traffic on working days indicate that, in the case of two of the schools during the morning traffic rush hours, significantly lower NO2 concentrations were observed in the period after the introduction of road traffic restrictions, compared with the period before they were introduced. NO2 concentrations during the morning peak hours (on working days) after introducing restrictions were more than 30% lower than the concentrations recorded during the same hours in the period before introducing restrictions. [ABSTRACT FROM AUTHOR]

It is important to reduce the negative environmental effects of non-road diesel engines, which are increasingly used in many facilities and machines, without loss of performance. Biodiesel is used as an alternative to fossil-based diesel fuels to eliminate these effects and ensure sustainability in energy. This study focused on the optimization of the operating parameters of a non-road diesel engine operating with a waste frying oil biodiesel mixture at 50% load. Pure biodiesel, 1-heptanol, different injection advances and pressures were determined as input parameters for optimization. The tests were designed according to Taguchi's L16 orthogonal array. ANOVA analysis was performed to determine the importance of input parameters on engine performance and exhaust emissions. Optimization was made based on the highest brake thermal efficiency (BTE) in addition to the lowest values of brake-specific fuel consumption (BSFC), brake-specific hydrocarbon (BSHC), brake-specific nitrogen oxide (BSNOx) and smoke emissions. In the optimization carried out according to the response surface methodology (RSM), the optimum combinations to obtain the best engine characteristics were determined as 17.27% 1-heptanol, a 226-bar injection pressure, 27 CAD injection advance and B75. These optimization results were verified by engine experiments within the recommended error range. [ABSTRACT FROM AUTHOR]

Hydrogen, as a zero-emission fuel, makes it possible to build a piston combustion engine that can be qualified as a drive for a "Zero Emission Vehicles", in terms of CO2 emissions. Thus, a hydrogen-powered piston combustion engine may be a future transitional technology for powertrains, especially in trucks and off-road vehicles, competitive with both electric drives and fuel cells. The article presents a multi-directional analysis of the prospects for the development and dissemination of hydrogen-powered internal combustion piston engines in motor vehicles. The current interest of the automotive industry in hydrogen-powered internal combustion engines, the current state of their development and the challenges that need to be overcome were presented. Various conditions that will determine their future in Europe were also indicated. [ABSTRACT FROM AUTHOR]

This article shows the effect of the addition of effective microorganisms and silver on the exhaust gas composition and fuel consumption. Exhaust emission standards are becoming increasingly stringent, which makes it difficult for engine manufacturers to meet them. For this reason, intensive work is underway to use alternative propulsion systems on ships, and for diesel engines, alternative fuels. Among other things, this applies to mixtures of petroleum-based fuels with vegetable oils and their esters. Unfortunately, their use, due to their physicochemical properties, can negatively affect the performance of the engine and the wear of its components. Therefore, the aim of this study was to see how additives of effective microorganisms in the form of ceramic liquid and tubes, and a silver solution and colloidal silver would affect some engine parameters, including the exhaust gas composition and fuel consumption. The authors are not aware of the results of previous research on this issue. The tests were carried out on a diesel engine for four types of green additives at concentrations of 2% and 5%, at different ranges of its load. The additives added to the diesel fuel were characterised, and the test stand was presented, along with the parameters of the tested fuel. The effect of additives on selected engine parameters, including fuel consumption, was presented. The characteristics of hourly fuel consumption and selected components of the exhaust gas, including nitrogen oxides, carbon monoxide and carbon dioxide as a function of the concentration of ecological additives are shown and analysed. It was found that the most beneficial additive that had a positive effect on the exhaust gas composition and fuel consumption was a silver solution in a 2% concentration. There was a decrease of up to 4% in the NOx content of the exhaust gas, a decrease in carbon monoxide of more than 28%, a decrease in carbon dioxide of 4.6% and a decrease in fuel consumption of around 3% was achieved under the tested conditions. The use of these additives is an innovative solution that has a positive impact on reducing the emissions of harmful compounds into the atmosphere. In further research, it will be necessary to study the effect of this additive on the combustion process in the engine and the wear of its components, as well as to confirm the results obtained in real operating conditions. [ABSTRACT FROM AUTHOR]

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This study focuses on the detailed analysis of exhaust emissions from multi-point fuel injection (MPFI) engines by manipulating the injection parameters through a programmable electronic control unit. In addition, tests are carried out using different generations of catalytic converters and checking that their working temperature is correct using a thermographic camera, verifying operation, to evaluate their effect on emission reduction. Detailed comparisons of the results between these configurations will allow the identification of the combination that reduces emissions the most without compromising engine efficiency and performance. This research aims to promote a more sustainable approach in the automotive sector by properly configuring systems, but also by demonstrating the technical robustness of their application in vehicles. It has also helped to verify that varying injection and ignition parameters help to fine-tune fuel injection, resulting in efficient combustion. Combining this variation with catalytic converters has further reduced exhaust pollutants. [ABSTRACT FROM AUTHOR]

To provide technical and economical solutions regarding management of plastic waste, which is constantly increasing worldwide, this study addresses the possibility of using plastic oils (PO) obtained from these plastic wastes as biofuels. To this end, the replacement of the fossil diesel employed in internal combustion diesel engines with triple diesel/PO/vegetable oil mixtures has been investigated. Sunflower (SO) and castor oil (CO) mixed with PO in the most appropriate proportion are evaluated as pure vegetable oils (SVO). Thus, diesel/PO/SVO triple blends were prepared, characterized, and then tested on a diesel engine operating as electricity generator, evaluating power output, consumption, and exhaust emissions. The obtained results show that, with the incorporation of relatively small quantities of pure, non-edible vegetable oils, in double mixtures of PO/SO and PO/CO, an effective alternative fuel for transport is obtained, that allows for 100% of fossil diesel to be replaced. In fact, with these double PO/SVO biofuel mixtures, higher engine power values and lower consumption levels are obtained than those achieved with fossil diesel. Regarding exhaust emissions, these are produced with a slightly greater opacity than with fossil diesel, but there are lower values of carbon gases as a whole (CO + CO2) and in NOx gases. [ABSTRACT FROM AUTHOR]

The present investigation analyzes the influence of water content in a biodiesel blend using palm oil mill effluent: POME (8%). Two water emulsion blends were tested: POME (8%) + H2O (5%) and POME (8%) + H2O (10%). The tests were performed on a stationary diesel engine operating at four load conditions (25%, 50%, 75% and 100%). From the results, it is shown that the blends POME (8%) + H2O (5%) and POME (8%) + H2O (10%) allow a decrease of 2.2% and 4.7% in NOx emissions. In this way, the NOx formation problems of biodiesel are minimized. The evaporation of the water microparticles in the blends POME (8%) + H2O (5%) and POME (8%) + H2O (10%) improves the homogeneity between the air and the fuel. This contributes to a 2.65% decrease in BSFC and a 1.65% increase in BTE compared to POME (8%). Additionally, water emulsions achieve a 14.6%, 7.3%, 13.4%, 1.8%, and 14.1% reduction in CO, CO2, HC, NOx, and smoke opacity emissions compared to conventional diesel. In general, the emulsified blends POME (8%) + H2O (5%) and POME (8%) + H2O (10%) contribute to a greater reduction in engine pollutant emissions, as well as an improvement in engine performance parameters when compared to POME (8%). [ABSTRACT FROM AUTHOR]

This study investigated the negative impact of exhaust back-pressure (EBP) on diesel engine performance and how it can be mitigated by advancing fuel injection timing (FIT). Experiments were conducted on a diesel engine with various EBP and FIT settings, and the impact of these factors on engine performance was evaluated under a constant load. The results showed that increasing EBP delayed the combustion process, resulted in longer ignition delay periods, and decreased engine efficiency. However, by advancing FIT, these negative effects could be mitigated to some extent. Specifically, advancing FIT led to shorter ignition delay periods, improved combustion rate, and earlier maximum pressure values. The study highlights the potential of controlling FIT as a promising approach to reduce the negative impact of EBP on diesel engine performance and environmental impact. The results of the study have practical implications for diesel engine operators seeking to offset the negative impact of EBP resulting from the integration of waste heat recovery or aftertreatment systems in the exhaust system, which is aimed at improving the efficiency and reducing the environmental footprint of diesel engines. [ABSTRACT FROM AUTHOR]

Liquefied natural gas (LNG) use as shipping fuel has increased in recent years. While LNG results in lower carbon dioxide (CO2) emissions as well as benefits in terms of air pollutants, the slip of unburned methane, the main component of LNG, has remained a concern. In this study, methane together with other climate warming agents, CO2 and black carbon (BC), as well as other emission compounds were characterized from 4-stroke low-pressure dual fuel engine on-board a newly build cruise ship utilizing LNG as well as marine gas oil (MGO). The brake specific methane slip was found to vary according to engine load, being 2.3–3.0 g/kWh at 54–80% loads, but increasing to 10 g/kWh at 25% load and 21 g/kWh at 12% load. The LNG combustion also resulted in higher formaldehyde emissions compared to MGO, but reduction in formaldehyde levels was observed over the SCR catalyst present in the exhaust line of the dual-fuel engine, without urea injection, suggesting it may provide a pathway for formaldehyde mitigation. In terms of particle emissions, LNG use reduced particle mass (PM) by 87–93% and BC by 94–99% compared to MGO combustion. Non-volatile particle number above 23 nm (PNnv,>23nm) and 10 nm (PNnv,>10nm) were reduced by 88–97% and 97–99%, except at lowest engine load where PNnv,>10nm increased by 26% compared to MGO utilization. When total greenhouse gas (GHG) emissions including CO2 and BC were considered, LNG use resulted in 13–15% lower GHG at high loads, but the benefit was undermined by the escaping methane at low load conditions. Following the engine activity profile during 8-months of vessel operation on the Mediterranean suggested, however, that in a diesel-electric cruise ship, low load conditions are used mainly during arrivals and departures from harbors, as the engine was operated at loads above 40% for 90% of the operation time. Weighted emission factor, representing the actual engine operation, resulted in methane slip of 2.8 g/kWh or 1.7% of the fuel use, which is below the value considered in the FuelEU Maritime. The results suggest that load specific methane slip, together with engine load profile should be considered when evaluating methane slip on vessel or fleet level.

Energy shortage and environmental pollution are becoming more serious, biodiesel is regarded as the most promising alternative fuel for diesel engines due to its environmentally friendly and renewable characteristics. In this study, the biodiesel-ethanol blends were used in a diesel engine, and the purpose of the study was to simultaneously control the NOx and soot emissions of the diesel engine by adjusting the injection strategy and EGR rate. A turbocharged, six-cylinder, common rail direct injection (CRDI) engine model was established using GT-Power. The effects of the main-post injection strategy and post injection coupled with exhaust gas recirculation (EGR) on combustion and emission characteristics were investigated at a maximum torque speed and a medium load. The results show that when the main-post injection strategy is employed, the combustion duration of the main injection is shortened with an increase in the main-post injection interval (MPI). When the MPI increased to more than 18 °CA, the heat release of post injection could be observed clearly from the curve of the heat release rate, NOx emissions decreased by 5.70% and 7.12%, respectively, and soot emissions decreased by 25.56% and 30.20%, respectively. Moreover, with the increasing post injection quantity, the combustion duration of the main injection shortened, and the peak heat release rate (PHRR) of the post injection increased. When the fuel quantity for the post injection increased from 2 to 6 mg, NOx emissions decreased from 2.33% to 9.80%, and soot emissions decreased from 16.10% to 34.97%. The effect of post injection quantity on emissions was more significant than that of the MPI. In addition, with increasing EGR rate, the ignition delay is prolonged, the peak cylinder pressure, PHRR, peak combustion temperature and NOx emissions decrease, whereas soot emissions increase gradually. Main-post injection can improve the NOx-soot trade-off, the optimal EGR rate is 22.86% under a post injection quantity of 4 mg and a MPI of 22 °CA.

Incorporating jatropha biodiesel into discarded plastic oil and diesel on diesel engines and analysis of six fuel samples, three diesel types and two waste plastic diesel and jatropha biodiesel combinations. Following characterisation, a one-cylinder, DI diesel engine underwent comprehensive performance and emissions testing, involving spectroscopy. Addition of jatropha biodiesel led to reduced viscosity and density of the waste plastic-diesel blend, a 20% decrease in flash point, and 10% reductions in BSEC and BSFC, while lowering the engine's thermal efficiency by 5%. Jatropha biodiesel increased HC by 30%, reduced CO and NOx emissions by 20% and 5%. Both diesel and WPF20D60JB20 exhibited a of 36.45%, with BSEC values at full load of 9.91 and 9.84 MJ/kW-hr. WPF20D60JB20 demonstrated the best performance.

Congestion pricing (CP) is widely considered to have significant potential for effectively reducing vehicle miles traveled, reducing emissions, and providing a reliable revenue source for transportation investments. This study evaluated cities interested in CP—five in the U.S. (Boston, Los Angeles, New York, San Francisco, Seattle) and two in other countries (Vancouver, Canada, and Auckland, New Zealand). This study examines the following features of a CP system for each of these cities: 1) duration of CP investigations, 2) equity mitigations, 3) range of alternatives considered, 4) public engagement, and 5) importance of emissions reductions. Timelines are impossible to predict with certainty, but New York and Auckland appear closest to implementation. Vancouver, San Francisco, and Seattle are well into the process; and Boston and Los Angeles are early in the process. Other key findings include that most of the cities start considering a range of options before narrowing down to comparing more detailed CP systems. Vancouver and San Francisco have made public engagement a cornerstone of their plan development, using polls and workshops to finetune the details of their CP proposals. In contrast, Auckland, while still engaging with stakeholders and experts for guidance, has mainly focused on how to ensure public support and understanding of the proposals they recommend. In terms of equity, discounts are a common and primary strategy proposed among the cities, but some also develop a more comprehensive set of equity policies to accompany a CP system.

This study conducts experimental and numerical investigations on a stagnation-point, reverse-flow combustor to examine the effect of its design features on the combustion behavior and emission characteristics of non-premixed, turbulent hydrogen/air flames. The study covers a wide range of equivalence ratios, from ultra-lean to stoichiometric, and thermal power inputs varying between 5 kW and 20 kW. The main motivation behind this design is to achieve passive recirculation of flue gas within the combustor to enhance dilution of the incoming charge, thus potentially leading to relatively uniform thermal fields, lower temperatures, and suppressed NO x emissions. This design concept is implemented in a micro gas turbine – a practical energy conversion device tapped to play a major role in decarbonizing CHP systems suitable for small-scale industries. Optical chemiluminescence measurements, in addition to thermocouple-based temperature and Quantum Cascade Laser (QCL) spectroscopy-based exhaust emissions measurements, were conducted for all the test cases. Spatial OH* signal intensity is used as heat release signature to identify distinct features of the test flames, allowing for useful information on the nature and dynamics of the combustion process within the combustor. The results show stable hydrogen/air flames for all the operating conditions; however, a more distributed combustion is observed at higher powers for all the given equivalence ratios. Relatively higher NO x emissions at φ >0.2 suggest the lower achieved mixing between burnt and fresh gases, particularly in the non-preheated case, prevent a thorough dilution of the fresh mixture. The latter is necessary to achieve low-temperature, uniform thermal fields – an essential for low thermal NO x emissions in gas turbine combustors. Further, CFD results show that preheating considerably changes flow field dynamics and recirculation pattern for better mixing; however, this also dramatically increases thermal NO x emission, with the lowest levels observed at φ = 0.2, while the peak occurs at φ = 0.4. Finally, a 'brute-force' sensitivity analysis shows that thermal NO and NNH pathways contribute the most to NO formation in hydrogen/air flames. • The viability of hydrogen as a carbon-free alternative fuel for micro gas turbines is studied. • Preheating extends hydrogen flame stability at ultra-lean conditions. • Fuel injection velocity strongly affects the extent of charge dilution. • Effectiveness of recirculation depends upon the degree of mixing. • Thermal NO and NNH pathways contribute the most to NO formation in H 2 flames. [ABSTRACT FROM AUTHOR]

Biodiesel is a good substitute for fossil diesel fuel. However, the high viscosity, low volatility, and poor cold flow properties restrain its use at a high blending ratio or pure in diesel engines. In this regard, blending low-viscosity and high-volatility biofuel with biodiesel is a feasible method to eliminate the disadvantages of biodiesel. It is a cost-effective solution rather than making engine modifications. In this study, the applicability of high-proportion biodiesel (B90) in an existing diesel engine is experimentally investigated by adding methyl acetate and ethyl acetate to biodiesel. An improvement in kinematic viscosity and cold filter plugging point temperature is observed for acetate-added biodiesel fuels. Methyl acetate and ethyl acetate included biofuels result in higher thermal efficiency and lower pollutant emission than sole biodiesel. But their engine performance is still poor compared to diesel fuel. Brake-specific fuel consumption is increased by 24.01–32.29% with acetate-added biodiesel fuels compared to diesel fuel. However, their favorable combustion characteristics increase engine thermal efficiency by up to 3.58% compared to neat biodiesel. CO, HC, NO concentrations, and smoke opacity reduce with acetate-blended biodiesel fuels compared to neat biodiesel. Both methyl acetate and ethyl acetate simultaneously reduce NO emissions and smoke opacity. It is an essential finding of this study, indicating that these oxygenated additives can potentially improve the NOX-PM trade-off in diesel engines. [ABSTRACT FROM AUTHOR]

Faced with the depletion of fossil fuels and increasingly serious environmental pollution, finding an environmentally friendly renewable alternative fuel has become one of the current research focuses. In order to find new alternative fuels, reduce dependence on fossil fuels, improve air quality, and promote sustainable development goals, castor biodiesel was produced through transesterification, and mixed with diesel in a certain proportion. The engine performance and emissions were compared and analyzed under fixed load and different speeds of agricultural diesel engines. Biofuel, as a fuel containing oxygen, promotes complete combustion to a certain extent. As the proportion of castor biodiesel in the mixed fuel increases, the emissions of pollutants such as CO, HC, and smoke show a decreasing trend. The lowest CO, HC, and smoke emissions were observed in the B80 blend at 1800 rpm, at 0.3%, 23 ppm, and 3%, respectively. On the contrary, the CO2 and NOx emissions of the B80 blend are higher than those of 2.7 diesel, reaching 2.5% and 332 ppm respectively at 1800 rpm. The lower calorific value and higher viscosity of biodiesel result in a decrease in BTE and an increase in the BSFC of the blends. Higher combustion temperatures at high speeds promote oxidation reactions, resulting in reduced HC, CO, and smoke emissions, but increased CO2 and NOx emissions. At high speeds, fuel consumption increases, BSFC increases, and BTE decreases. Overall, castor biodiesel has similar physical and chemical properties to diesel and can be mixed with diesel in a certain proportion for use in CI engines, making it an excellent alternative fuel. [ABSTRACT FROM AUTHOR]

The article considers variables registered in the WLTP procedure. The test results of a passenger car with a compression-ignition engine have been analysed. The tests were carried out on a chassis dynamometer. The tests were performed for engine cold start and ran up to the point of reaching stabilized operating conditions. The average specific distance emissions and volumetric fuel consumption were assessed for individual test phases as well as for the entire test. It was found that the results in the first test phase, which corresponded to the engine cold start up to stabilized operating conditions, had the most significant impact on the overall exhaust emission and fuel consumption results in the test. The specific distance emissions of carbon monoxide, non-methane hydrocarbons and nitrogen oxides were by far the highest in the first phase of the test. In the fourth phase of the test, the specific distance emissions of methane and carbon dioxide turned out to be the highest, as well as the operational volumetric fuel consumption being the highest. [ABSTRACT FROM AUTHOR]

This experimental work highlights the superiority of hydrogen fuel on the performance, exhaust emission and exergy parameters of a compression ignition engine fueled with ethanol-jatropha biodiesel blend. The engine is operated at 25%, 50%, 75% and 100% of full load conditions and at a constant speed of 1500 rpm (±5 rpm) for the five different hydrogen injection durations, such as, 1200, 2500, 3700, 4500 and 6000 μs. The results shows that the 10% ethanol + 90% jatropha biodiesel (BE10) slightly improves the performance, emission and exergy parameters of the engine. The small addition of hydrogen, especially for the injection duration 2500 μs, to the BE10 has shown an improvement in brake thermal efficiency (2.09–2.92%), exergetic efficiency (1.85–2.67%), exergy destruction rate (1.72–7.05%) and entropy generation (4.26–9.47%). The increasing hydrogen share into the hybrid blend notably reduces the unburned hydrocarbon, carbon monoxide and particulate matter with slightly higher oxides of nitrogen emissions. • The hydrogen addition to ethanol-jatropha biodiesel improves the brake thermal efficiency. • The UHC, CO and PM emissions are significantly reduced with the increasing hydrogen share. • BE10H1 and BE10H2 strategies have demonstrated lower NO X emissions than diesel. • The exergetic efficiency, exergy destruction rate and entropy generation are improved with the hydrogen addition. [ABSTRACT FROM AUTHOR]

Current challenges in terms of exhaust emission limits are related to the reduction of the particle numbers in spark ignition direct injection engines. The article concerns the analysis of the thermodynamic parameters of engine operation, allowing the selection of the particulate filter configuration and its technical parameters. The designed system consisting of an internal combustion engine and an exhaust system with an exhaust gas treatment system should be sufficient to meet ecological requirements in the form of reducing particulate matter emissions. The analysis of particulate matter emissions for the system without a filter and with a filter installed in the engine exhaust system was carried out for the mass, number and dimensional distribution of particulate matter. The result was an assessment of filtration efficiency for the entire spectrum of particulate diameters in the identified engine operating ranges. As a result, it was found that the particulate filter used in the engine exhaust system effectively reduces the particle number due to the greater filtration efficiency of large particles. The summary of the work related to the analysis of the ecological parameters of a spark ignition engine with direct fuel injection was a simulation of road tests of a vehicle with the proposed modified vehicle exhaust system equipped with a particulate filter. For this configuration, the analysis of particulate number emissions in the parameterized engine operating areas showed that it is possible to meet the particulate number emission limits, and the obtained road emission results are fully acceptable in terms of the obtained absolute values. [ABSTRACT FROM AUTHOR]