Engine Emissions Research Articles

Optimization of operational parameters of marine methanol dual-fuel engine based on RSM-MOPSO

Methanol and natural gas, as green fuels for environmental protection, have shown great potential in the field of maritime transportation. This study explores how the methanol energy fraction (MEF), exhaust gas recirculation (EGR), excess air ratio (λ), and engine injection timing (EIT) influence combustion and emission traits in marine dual-fuel (DF) engine. Initially, a DF engine model was formulated through experiments using CONVERGE software, while the CHEMKIN program devised a chemical mechanism involving 100 compounds and 512 reactions. The response surface methodology (RSM) was subsequently utilized to design the experiment and develop the regression model. The improved multi-objective particle swarm optimization (MOPSO) algorithm was applied to optimize three critical variables: brake thermal efficiency (BTE), carbon monoxide (CO), and nitrogen oxide (NOx) emissions. Ultimately, feature-optimized scenarios from the Pareto front were chosen for comparative evaluation to derive the optimal configuration. The results show that when the decision variables MEF, EGR, λ and EIT are 22.33 %, 10 %, 1.81 and 11°CA BTDC respectively, there is a better trade-off between the three target variables. Compared with the original case, the change of ITE, NOx and CO emissions in the optimal case are +0.97 %, −39.53 % and −14.51 %, respectively. Overall, based on the intelligent optimization approach, the rational selection of DF engine parameters improved the ITE and most NOx and CO emissions were effectively suppressed.

Onboard test-based exhaust emission factors for marine diesel engines on anchor handling tug supply vessels

In order to accurately assess China’s port air pollution caused by AHTS (Anchor Handling Tug Supply Vessels) ships, 46 diesel engines on 27 AHTS ships were tested for onboard emissions using a large gas analyzer to statistically analyze their fuel-based and power-based emission factors. The results show that fuel-based NOx-emission factors for MEs, SEs and AEs before and after the use of the SCR system are 45.4, 38.24,33.04 g/kg and 6.35, 4.98, 5.82 g/kg, CO-emission factors are 7.95, 6.30, 7.96 g/kg and 6.90, 6.93, 8.32 g/kg, THC-emission factors are 0.49, 0.64, 0.25 g/kg and 0.42, 0.47, 0.22 g/kg, and CO2-emission factors are 3121.62, 3121.34, 3093.12 g/kg and 3088.14,3091.40, 3085.21 g/kg, respectively. Power-based NOx-emission factors for MEs, SEs and AEs before and after the use of the SCR system are 9.71, 8.61, 7.58 g/(kW·h) and 1.37, 1.23, 1.33 g/(kW·h), CO-emission factors are 1.71, 2.08, 1.84 g/(kW·h) and 1.47, 1.53, 1.93 g/(kW·h), THC-emission factors are 0.10, 0.14, 0.05 g/(kW·h) and 0.09, 0.13, 0.06 g/(kW·h), and CO2-emission factors are 671.73, 700.58, 718.46 g/(kW·h) and 664.42, 694.16, 716.92 g/(kW·h), respectively. The power-based emission factor is closely related to the diesel engine load, and the relationship between different exhaust emissions and diesel engine load shows different patterns. In addition, it was found that the NOx emissions of the ship decreased significantly to meet the IMO Tier III requirements after running SCR. The emission factors of CO, HC and CO2 have no obvious change whether SCR systems were operated or not. The AHTS marine engine emission factors obtained in this paper are highly relevant and can provide reliable data for establishing a suitable emission inventory for medium and high speed engineering support vessels.

Combustion and emissions of an ammonia heavy-duty engine with a hydrogen-fueled active pre-chamber ignition system

Combustion and emission characteristics of a heavy-duty single-cylinder ammonia engine with a hydrogen-fueled active pre-chamber ignition system are investigated experimentally at the condition of IMEP 10 bar, 1000 rpm, where effects of spark timing, excess air ratio (λ), and hydrogen energy ratio are tested. Three distinguishable combustion phases are observed, including pre-chamber combustion, turbulent-jet-controlled combustion, and ammonia-chemical-kinetics-controlled combustion. Advancing spark timing makes combustion phases earlier, increasing pressure rise rate, combustion pressure, and NOx emissions. The optimal spark timing for the highest indicated thermal efficiency (ITE) is −12°CA ATDC in the experiment. λ range for stable combustion is 1.1–1.5 and ITE peaks at λ = 1.3. The hydrogen energy ratio, 7.9%∼10.5%, has little influence on the engine performance. However, a low hydrogen energy ratio could increase the risk of misfire. The optimal hydrogen energy ratio is about 9∼10%.

Thermal and emission analysis of waste plastic and microalgae biodiesel as a potential power source for diesel engines: A sustainable approach.

The future of diesel engines is greatly influenced by ongoing research on alternative fuels. Renewable fuels have been researched and adopted by several nations to encourage the production and use of biodiesel. This study examines the energy conversion of waste plastic biodiesel and Spirulina microalgae biodiesel at a 20% blending ratio to analyze the behavior of a one-cylinder, 4-stroke diesel engine running at 1500rpm with a compression ratio of 17.5. The authors evaluated, analyzed, and compared the engine's combustion, performance, and emission at an incremental engine load of 25% from 25 to 100%. The findings demonstrated that the biodiesel fuel samples generated somewhat poorer efficiency but reduced emissions from the engine. At 100% load, the percentage differences between the diesel and blended fuel samplesranged from 2.4 to 7.3% for BTE, 2.9 to 16.5% for BSFC, and 1.0 to 4.62% for BSEC; however, the PM, SO2, and CO2 emissions were reduced by 1.6-28.8% except for NOx emissions, which are increased by up to 9.4%. Pure diesel exhibits the best performance characteristics; however, pure biodiesel exhibits the best emission characteristics. The 20% blended fuels showed promising results, as they exhibited comparable or slightly improved BTE values compared to their respective pure biodiesel fuels. The findings indicate that Spirulina microalgae biodiesel and waste plastic biodiesel have the potential to be utilized as substitute fuels for diesel engines; however, for the greatest performance and lowest emissions, their blending ratios and engine operating conditions must be optimized.

Innovative Metal Coating Strategies for Enhanced Engine Performance and Emission Mitigation in Internal Combustion Engines: A Comprehensive Review

This comprehensive work addresses the pressing environmental concerns associated with the automotive industry`s expansion and its reliance on fossil fuels. Focusing on the pivotal role of energy in vehicle propulsion, the paper explores diverse energy utilization methods and their conversion into mechanical energy for mobility. While chemical energy currently powers most vehicles, it contributes to detrimental emissions, necessitating innovations to enhance fuel quality, engine design, and materials. The research emphasizes refining the performance, and life cycle, and minimizing exhaust emissions of internal combustion engines. A key focus of this paper is the proposal of a novel approach that advocates the application of coatings to the combustion surface and catalytic converter to bolster engine performance and curtail emissions. The researchers highlight the efficacy of metal coatings, including thermal barrier coatings and catalytic coatings, presenting a comprehensive overview of experimental research articles endorsing the positive impact of metal coating strategies. These coatings aim to enhance combustion dynamics, manage thermal stresses, and optimize catalytic converter efficiency. In this technical paper offers valuable insights for researchers and engineers committed to mitigating the environmental impact of the automotive industry. It underscores the critical need for optimizing engine performance and minimizing emissions, with a specific emphasis on the promising potential of metal coating technologies to significantly contribute to these overarching objectives.

Effects of High-Density Polyethylene (HDPE) and Additives Fuel Blends on Diesel Engine’s Performance and Emissions and NOx Prediction using Boosted Tree Model

The rising demand for eco-friendly and sustainable fuel options has prompted the investigation of alternative energy sources. This study explores the use of blends of High-Density Polyethylene (HDPE), and 7% biodiesel (B7) with additives as a substitute for diesel fuel. The research involves comparing three different mix ratios of HDPE and additives with a conventional B7 blend: a control of 100% B7, a mix of 90% B7 with 10% HDPE, and a blend of 85% B7 with 10% HDPE and 5% additives. Fourier Transform Infrared (FTIR) spectroscopy was employed to identify the fuels' functional groups. The study also measured key performance metrics, including brake-specific fuel consumption (BSFC), brake power (BP), and exhaust emissions of nitrogen oxides (NOx), carbon monoxide (CO), hydrocarbons (HC), and carbon dioxide (CO2). A Boosted Tree Model was used to establish a prediction and analysis of NOx emissions. The findings indicate that incorporating additives into the HDPE blend positively influences both engine performance and emissions. The combination of HDPE and additives with B7 resulted in reduced emissions across various engine loads and speeds, decreasing hydrocarbon and carbon-containing emissions. The Boosted Tree Model, with a configuration of 4 leaf nodes, demonstrated strong predictive accuracy, with a coefficient of determination (R2) of 0.86 and a root-mean-square error (RMSE) of 0.38 for the training dataset, and R2 of 0.97 with RMSE of 0.16 for the validation dataset. The study underscores the benefits of integrating HDPE and additives into diesel blends, highlighting their potential to lower emissions and supporting the search for viable alternative fuels.

Enhancing engine performance, combustion, and emissions characteristics through CeO2-modified cottonseed biodiesel with hydrogen enrichment: A comprehensive investigation

This investigation delves into the combined use of nanoparticles added biodiesel blends and hydrogen as secondary fuels in CI engines, intending to minimize the reliance on traditional fossil fuels. Calcined wood ash (CWA) has been used as a heterogeneous catalyst for the preparation of cottonseed biodiesel. XRD, SEM and BET analysis was performed to characterize the catalyst. This study evaluates the impact of adding hydrogen and Cerium oxide (CeO2) nanoparticles to cottonseed biodiesel on a CRDI engine. It showed that H2 at an intake rate of 10 L/min improved the engine's overall performance and reduced hazardous emissions. By incorporating the CeO2 nanoparticles (75 ppm) in a cottonseed biodiesel blend and injecting H2 in the engine the BTE was enhanced by 27.8% and BSFC was decreased by 4.41%. There was a reduction of 24%, 22.8%, 6.42%, and 69.5% for HC, CO, CO2 and smoke emissions. On the other hand, NOx rose by 9.3% compared to diesel. The combustion characteristics, such as cylinder pressure showed 26.5% improvement at full load on inclusion of H2. Additionally, under maximum load, the blend C20 + CeO2+H2 has the shortest ignition delay and combustion duration leading to higher engine efficiency. The results of this investigation offer valuable insights into the potential of biodiesel-hydrogen dual-fuel strategies to reduce the environmental impact of CI engines while promoting sustainable energy practices.

Hydrogen enrichment in methanol SI engine at varying injection timing during compression stroke

This study investigates the effect of hydrogen enrichment in a direct-injected methanol-fuelled SI engine, with combustion and emission performance analysed by varying the methanol injection timing from 150° to 60° CA bTDC. A three-dimensional computational fluid dynamic model of the hydrogen-enriched methanol engine was developed to predict the engine performance, in-cylinder, and emission characteristics. The numerical model was solved using three-dimensional Reynolds-Averaged Navier Stokes, the RNG k-epsilon model for turbulence, the O'Rourke and Amsden sub-model for heat transfer, the extended Zeldovich mechanism for nitric oxide emissions, and the Hiroyasu-NSC model for soot emissions. The results indicated that retarding the injection timing resulted in a decrease in the indicated specific CO and soot emissions along with a rise in the indicated specific NOx emissions. Furthermore, hydrogen enrichment with methanol enhanced the hydroxyl radical concentration, reduced the combustion duration, reduced also the indicated specific CO and soot emissions while increasing the indicated specific NOx emissions. The study indicates that hydrogen enrichment could extend the late injection timing limit of methanol by enhancing fuel-air mixing, which improves and controls the combustion process more effectively.

Emission inventory of IVOCs from diesel engine emissions in China based on real-world measured data

Intermediate volatility organic compounds (IVOCs), recognized as significant precursors of secondary organic aerosols, play a pivotal role in environmental pollution. This study utilized measured real-world emission factors to construct an inventory of IVOC emissions from diesel engines and to analyze their spatial distribution across China in 2022. Furthermore, the emission inventory derived from this approach was compared with that obtained through the IVOC/primary organic aerosol (POA) ratio method. The following findings were observed: (1) In 2022, the total IVOC emissions from diesel engines in China amounted to approximately 430 Gg, surpassing those emitted by gasoline engines and residential solid fuel combustion. Specifically, the IVOC emissions attributed to on-road diesel vehicles, inland vessels, agricultural machinery, and non-road construction machinery were recorded at 377, 39.3, 10.4 and 3 Gg, respectively. (2) In terms of geographical distribution in 2022, IVOC emissions from diesel engines were predominantly concentrated in Eastern, Southern and Northern China; on-road diesel vehicle emissions were primarily located within logistics hubs or regions characterized by extensive national and arterial road networks; while non-road construction and agricultural machinery emissions were largely confined to Eastern and Central China. Emissions from inland vessels exhibited a more distinct regional pattern concentrated mainly within the Yangtze River Delta, Pearl River Delta, and Bohai Rim areas. (3) A comparative analysis between the inventory established using real-world measured emission factors and that derived via IVOC/POA ratios indicated that the latter methodology may have overestimated emissions associated with inland vessels and non-road construction machinery. Moving forward, reducing IVOC emissions from diesel engines is crucial for enhancing air quality and safeguarding human health-particularly concerning heavy-duty vehicles, light-duty vehicles, and inland vessels.

Investigation of the optimal timing and amount of fuel injection on the efficiency and emissions of a diesel engine through experimentation and numerical analysis

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 <5.6 %). Design Expert software was used to optimize the dependent variables (peak chamber temperature, brake mean effective pressure, engine torque, engine thermal efficiency and emissions of NOx) according to the studied variables (injection time and fuel injection quantity) based on response surface methodology. The results show that the recommended injecting time of 342 °C and the specific amount of fuel lead to better combustion efficiency, resulting in high engine performance and low emissions. The specific fuel consumption was highest at 2200 rpm with a 50 % load, while the lowest SFC level was observed at 1750 rpm with a 100 % load. The maximum value of NOx emissions was observed at full load. The findings show that the optimization of the injection timing and fuel injection quantity can effectively enhance the performance of the MTE660E engine. The study provides valuable insights into improving combustion efficiency, resulting in greater performance and reduced emissions without requiring expensive overhaul. It has potential applications in automotive and commercial transportation industries, thereby reducing fuel consumption and emissions.

Effects of industrial hydrogen-rich gases on the performance of the spark ignition engine under various combustion modes

Hydrogen is emerging as a promising alternative to traditional fossil fuels for the transportation. Additionally, the hydrogen-rich gases (HRG) can produce on a large scale during the process of chemical production. In this study, the influences of HRG on the performance behaviors of the spark ignition (SI) engine are comprehensively analyzed under various combustion modes and operating conditions. The experimental results indicate that with increasing the lambda, the torque of the test engine can maintain the target value under equivalent ratio and lean combustion modes, while it sharply decreases under ultra-lean combustion. When the value of the lambda is 1.5, the brake thermal efficiency (BTE) and brake specific hydrogen consumption (BSHC) of the HRG SI engine respectively reach up to 33.6% and 89.1 g/kW.h, yielding superior fuel economy. The NOx emissions of the HRG SI engine firstly increase and then decrease with increasing lambda, reaching the peak value at the lambda of 1.1. In addition, the NOx, CO, and HC emissions of the HRG SI engine greatly reduce when the lambda is approximately 1.5. Consequently, using HRG partially substitute the traditional fossil gasoline in the SI engine can benefit to achieve energy conservation and emissions reduction in transportation section.

Parametric study of combustion characteristics of diesel/methanol dual fuel engine using global sensitivity analysis and multi-objective optimization

The pursuit of clean and efficient internal combustion engine power necessitates the substitution of fossil fuels with methanol and the adoption of advanced combustion strategies. This study examines the combustion and emission characteristics of methanol/diesel dual-fuel compression ignition engines. To understand the intricate interplay between critical parameters and engine performance, the global sensitivity analysis (GSA) method is employed, utilizing Sobol sensitivity as the quantitative metric. The investigated parameters include methanol substitution rate, diesel injection parameters, and five thermodynamics parameters concerning in-cylinder conditions. A validated computational fluid dynamics (CFD) model, coupled with a chemical kinetic mechanism, is developed to predict the combustion behavior of the dual-fuel engine accurately. This predictive capability forms the basis for utilizing the tree-based process optimization (TPOT) algorithm. By implementing TPOT, a significant reduction in the mean square error (MSE) of the predicted characteristics model is achieved, averaging a decrease of 73.59%. Subsequently, a multi-objective optimization is conducted, exploring the impact of varying target weights on the optimal outcomes. Results show the initial pressure significantly impacts the engine's economy, power and emission characteristics, and NOx formation should be carefully considered in the combustion optimization of dual-fuel engines.

To Enhance the Performance of CI Engine with Using of Additives Based Hybrid Bio Fuel—A Review

AbstractThe growing demand of sustainable and environment friendly energy sources has spurred research and development efforts towards the integration of biofuels in various applications, particularly in internal combustion engines. Microemulsion technique is a new and innovative alternative to traditional fossil fuel that has gained a significant attention in recent years. This type of bio fuel is made by blending of small amount of biofuel and large amount of conventional diesel fuel. This review paper explores the potential of enhancing the performance of Compression ignition (CI) engines by incorporating additives into hybrid biofuels. The study focuses on the synergistic effects of combining traditional fossil fuels with bio‐derived components, such as ethanol, biodiesel, and other bio‐based additives. This review paper aim is to explore the performance of a 4‐stroke, single‐cylinder, direct injection Compression Ignition (CI) engine at different loads using different fuels blends like CNWEDB, BFNP150, PPNP150, and ME Diesel/Colza oil. The review outlines recent advancements in biofuel technology, including novel production methods and feedstock options, aiming to overcome limitations associated with conventional biofuels. The article aims to investigate the potential of vegetable oil in formulating MHBF, analyzing its performance and emissions in CI engines. The engine performance parameters viz., brake thermal efficiency brake specific fuel consumption have been reviewed and found that these values are comparable to the biodiesel blends with pure petrodiesel. At 60%, 80%, and full load condition the BTE of microemulsion diesel/colza oil is increasing while at 40%, 80%, and full load the BSFC is decreasing. Emissions reported by the various researchers, however, have a positive attribute with respect to NOx, CO, and UHC. At full load CO is decreasing and at all load conditions the value of UHC is decreasing. The paper concludes with a discussion on future research directions, emphasizing the need for continued innovation to address emerging issues and optimize the performance of CI engines for a sustainable and energy‐efficient future.

Effect of hybrid nanoparticles dispersed ternary fuel blend on diesel engine performance and emissions: Experimental and Taguchi-Grey relation study

The present study deals with the influence of hybrid nanoparticles dispersed in ternary fuel mixtures on the evaluation of the performance and emission characteristics of a single cylinder diesel engine. The fuel blend consists of 70% diesel, 20% Madhuca longifolia biodiesel, and 10% ethanol (by volume). The hybrid nanoparticles of ferric chloride (FeCl3) and graphene nanoparticles were then added to this ternary fuel mixture in different proportions, namely 50 mg/L and 75 mg/L, together with the surfactant and the dispersant in a ratio of 1:1. Moreover, the experiments were conducted on a diesel engine to evaluate the performance and emission parameters by varying different fuel samples, different loads (3, 6, 9, and 12 kgf) and injection pressures (i.e. 200, 225,and 250 bar). In addition, the Taguchi-Grey relation analysis was used for optimization, and the input parameters are fuel samples, loads and injection pressures. Experimental performance metrics, including brake specific fuel consumption (BSFC) and brake thermal efficiency (BTE), were improved when hybrid nanoparticles were added to the ternary fuel blend compared to diesel. At the same time, smoke opacity, nitrogen oxides (NOx), unburned hydrocarbons (UHC) and carbon monoxide (CO) emissions were reduced. Increasing the injection pressure also led to positive results, apart from NOx. Both performance and emissions were better for hybrid nanofuel based on surfactants and dispersants than for the base fuel, and it performed better of all dispersant-added nanofuels. The better results were obtained with D70B20E10NPs75QPAN75 mg/L than with the other fuel samples. The maximum BTE and lowest BSFC are 33.26% and 0.206 kg/kWh, while the minimized CO, UHC, NOx and smoke values at full load are 0.019%, 21 ppm, 833 ppm and 36.25%, respectively, at full load and injection pressure of 250 bar. By combining experimental investigations with the Taguchi -Grey method, a comprehensive and rapid assessment of the effects on the performance and emission characteristics of diesel engines was achieved.

Performance analysis of dual-fuel engines using acetylene and microalgae biodiesel: The role of fuel injection timing

This study evaluates the impact of varying fuel injection timing (FIT) and dual-fuel modes on the performance and emissions of a compression ignition (CI) engine under different load conditions. The biodiesel used was derived from Chlorella protothecoides microalgae through a two-step transesterification process, and its elemental composition was characterized using gas chromatography-mass spectrometry (GC-MS). Acetylene gas was introduced into the engine intake manifold at a rate of 3 L per minute (LPM), while a blend of 20 % methyl ester from Chlorella protothecoides (B20 MEOA) served as the primary injected fuel. To predict engine performance and emission characteristics, advanced machine learning models were employed and evaluated using four statistical criteria, including R-squared, mean absolute error (MAE), and mean squared error (MSE). Experimental results indicated that the optimal configuration involved a dual-fuel mode combining B20 MEOA with acetylene gas and an advanced FIT of 25° before top dead center (bTDC). Performance analysis revealed that under all load conditions, the specific fuel consumption (SFC) decreased by 7.3 %, while brake thermal efficiency (BTE) increased by 1.6 % compared to conventional diesel. Emission testing showed a 7.6 % rise in nitrogen oxide emissions, alongside significant reductions in unburned hydrocarbons (12.5 %), carbon monoxide (25.6 %), and smoke intensity (7.5 %) relative to standard diesel operation. Optimization of the engine parameters ensured that key metrics, such as brake power (BP) and brake-specific fuel consumption (BSFC), remained within acceptable limits. The random forest model outperformed other machine learning models, demonstrating superior accuracy in predicting performance and emissions across all statistical measures. This study underscores the potential of combining advanced biodiesel blends with optimized FIT strategies to improve engine efficiency and emissions control, offering a promising approach for sustainable dual-fuel engine operations.

Comparative Study on DI Diesel Engine Performance and Emissions using HCP microalgae biodiesel, Mahua oil biodiesel, Rubber seed oil biodiesel and Petroleum diesel

Abstract Energy consumption of the world is increasing hence the prices of fuels are increasing. Fossil fuels are the major source of energy but they are depleting in nature and they may exhaust in future. So we cannot depend on these sources and biofuels can be considered as substitute for fossil fuels, hence lot of researchers are doing extensive research on biofuels. So it is important to study the performance of different biofuels to find suitable one in terms of food crisis and better engine performance. Accordingly in this study the performance and emissions characteristics of Rubber seed oil, Mahua oil and microalgae oil biodiesels are studied. The results of this comparison study carried with HCP-B20, MO-B20 and RSO-B20 biodiesel blends indicates that the performance of HCP-B20 blend is better and emissions are lower compared to MO-B20 and RSO-B20 blends. The higher content of oxygen present in the microalgae biodiesel leads to higher rate of combustion reactions, in turn complete flame propagation and improved combustion. The BTE is lower with HCP-B20, MO-B20 and RSO-B20 compared to PD. Added advantage with this microalgae biofuel is, it is non-edible, it doesn’t require fertile land for its growth. So HCP-B20 blend may be viable for the commercial application.

Investigation the Thermal Behavior of Lemon and Orange Peels Composite Fuel Diesel

Background: The aim of this research is to investigate the thermal behavior of a composite fuel prepared by mixing diesel fuel with citrus peel powder in the presence of activators and combustion accelerators. The study focused on utilizing abundant citrus waste, such as lemon and orange peels, as sustainable bioresources to reduce environmental pollution and optimize fuel efficiency. The research explored the thermal properties of the composite fuel and compared it with pure diesel through combustion experiments conducted at atmospheric pressure and combustion pressure in the engine. Methods: The study set the limits of the investigation to various proportions of lemon and orange peel powder mixed with diesel, ranging from 5% to 15% by mass of the total fuel composite. Two catalysts, sodium hydroxide (NaOH) and sulfuric acid (H2SO4), along with calcium oxide (CaO) powder were incorporated into the mixtures as activators to enhance combustion efficiency. The composite fuel characterization included thermogravimetric analysis (TGA) and thermographmetric station experiments to observe the combustion processes and assess the thermal behavior of the composite fuel. Results: The results revealed four distinct phases of combustion during the burning time of 60 seconds: volatile combustion, liquid combustion, combustion of solid materials, and the interaction of active substances with combustion residues. Using activators and catalysts significantly enhanced combustion efficiency and minimized the amount of residue produced during the process, resulting in thermal behavior that is more similar to that of pure diesel. Lemon peel powder with activators demonstrates better thermal behavior compared to orange peel powder. Conclusions: Based on the findings, some recommendations are proposed for further development such as the optimization of activator ratios, exploration of different proportions of lemon and orange peel powder, and investigation of other catalysts. Real-world engine performance tests and emission profile analysis can validate the thermal behavior results obtained from combustion experiments.

Investigation of The Effect of Adding Natural Gas to A Gasoline Engine On Engine Performance and Emissions

Petroleum-based fuels are generally used in internal combustion engines. Petroleum-based fuels now have difficulty meeting Euro standards in terms of emissions. That's why different methods are used. One of these is that adding natural gas to fuels can be beneficial in reducing emissions and increasing engine performance. In the experimental study, the engine performance and emissions of adding natural gas at different rates (50, 100, 150 and 200 g/h) into the intake air of an engine using gasoline fuel at different torque values (5, 10, 15 and 20 Nm) at a constant 3000 rpm were examined. The engine used in the study is a Lombardini LGW 523 MPI gasoline two-cylinder engine. When the experimental results are examined, the addition of natural gas to gasoline fuel reduces fuel consumption. The lowest values in specific fuel consumption were obtained when natural gas was added. Emissions decreased with increasing torque. As the natural gas addition rate increased, the thermal efficiency increased.

Evaluation of the Possible Effects of Varying the Volumetric Ratio of Lpg on the Spark Ignition Engine's Performance, Emissions, and Combustion

This study investigated the performance, emission reactions, and combustion of liquefied petroleum gas (LPG) at various volumetric ratios with gasoline. The experiments were carried out on a single cylinder spark ignition (SI) engine at different engine loads (500 to 3000 W). In general, the use of LPG has a negative effect on performance and combustion, while making a positive contribution to emissions. The brake thermal efficiency (BTE) and brake specific fuel consumption (BSFC) values closest to 100% gasoline were obtained with 25% LPG and were lower by 0.36% and 4.55%, respectively. Conversely, using LPG resulted in lower emissions of carbon dioxide (CO2), hydrocarbons (HC), and carbon monoxide (CO). The lowest emissions were obtained with the use of 100% LPG as 0.5%, 65 ppm and 9.5%, respectively. Compared to 100% gasoline, 20.63%, 27.78% and 5.19% improvements were achieved. Finally, the cylinder gas pressure value was negatively affected using LPG. Compared to 100% gasoline, the gas pressure value obtained with 75% LPG content fuel was 7.81% lower. It has been concluded that LPG is an environmentally friendly alternative fuel in terms of emissions, and considering the decrease in performance values, 25% LPG can be used successfully in SI engines instead of 100% LPG.

Effects of Magnetic Fields and Nanoparticle Additives on Diesel Engine Emissions and Performance: A Comprehensive Experimental Analysis

T. In the present study, performance and emission changes in a compression ignition engine were investigated by combining two methods. The first method involves adding nanoparticle additives to diesel fuel. Titanium dioxide (TiO2) with a particle size of 21 nm was used as nanoparticle. TiO2 was added to diesel fuel at doses of 50 mg and 100 mg per 1 kg (50 and 100 ppm). After adding the nanoparticle to the diesel fuel, each mixture was stirred with a mechanical stirrer for one hour. In the second method, a magnetic field of 1 tesla was created around the fuel. Neodymium magnets were placed circularly around the diesel fuel line to create the magnetic field. The experiments were carried out at 660 RPM engine speed and 100% torque. During the experiments, data on engine performance, in-cylinder pressure and emissions were recorded. This study aims to contribute to the development of alternative fuel applications to improve performance and emissions in compression ignition engines.